Multiple ABC glucoside transporters mediate sugar-stimulated growth in the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120.

PubMed

Nieves-Morión, Mercedes; Flores, Enrique

2018-02-01

Cyanobacteria are generally capable of photoautotrophic growth and are widely distributed on Earth. The model filamentous, heterocyst-forming strain Anabaena sp. PCC 7120 has long been considered as a strict photoautotroph but is now known to be able to assimilate fructose. We have previously described two components of ABC glucoside uptake transporters from Anabaena that are involved in uptake of the sucrose analog esculin: GlsC [a nucleotide-binding domain subunit (NBD)] and GlsP [a transmembrane component (TMD)]. Here, we created Anabaena mutants of genes encoding three further ABC transporter components needed for esculin uptake: GlsD (NBD), GlsQ (TMD) and GlsR (periplasmic substrate-binding protein). Phototrophic growth of Anabaena was significantly stimulated by sucrose, fructose and glucose. Whereas the glsC and glsD mutants were drastically hampered in sucrose-stimulated growth, the different gls mutants were generally impaired in sugar-dependent growth. Our results suggest the participation of Gls and other ABC transporters encoded in the Anabaena genome in sugar-stimulated growth. Additionally, Gls transporter components influence the function of septal junctions in the Anabaena filament. We suggest that mixotrophic growth is important in cyanobacterial physiology and may be relevant for the wide success of these organisms in diverse environments. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Genetic diversity among and within cultured cyanobionts of diverse species of Azolla.

PubMed

Sood, A; Prasanna, R; Prasanna, B M; Singh, P K

2008-01-01

The cyanobionts isolated from 10 Azolla accessions belonging to 6 species (Azolla mexicana, A. microphylla, A. rubra, A. caroliniana, A. filiculoides, A. pinnata) were cultured under laboratory conditions and analyzed on the basis of whole cell protein profiles and molecular marker dataset generated using repeat sequence primers (STRR(mod) and HipTG). The biochemical and molecular marker profiles of the cyanobionts were compared with those of the free-living cyanobacteria and symbiotic Nostoc strains from Anthoceros sp., Cycas sp. and Gunnera monoika. Cluster analysis revealed the genetic diversity among the selected strains, and identified 3 distinct clusters. Group 1 included cyanobionts from all the 10 accessions of Azolla, group 2 comprised all the symbiotic Nostoc strains, while group 3 included the free-living cyanobacteria belonging to the genera Nostoc and Anabaena. The interrelationships among the Azolla cyanobionts were further revealed by principal component analysis. Cyanobionts from A. caroliniana-A. microphylla grouped together while cyanobionts associated with A. mexicana-A. filiculoides along with A. pinnata formed another group. A. rubra cyanobionts had intermediate relationship with both the subgroups. This is the first study analyzing the diversity existing among the cultured cyanobionts of diverse Azolla species through the use of biochemical and molecular profiles and also the genetic distinctness of these free-living cyanobionts as compared to cyanobacterial strains of the genera Anabaena and Nostoc.

Cellulose in Cyanobacteria. Origin of Vascular Plant Cellulose Synthase?

PubMed Central

Nobles, David R.; Romanovicz, Dwight K.; Brown, R. Malcolm

2001-01-01

Although cellulose biosynthesis among the cyanobacteria has been suggested previously, we present the first conclusive evidence, to our knowledge, of the presence of cellulose in these organisms. Based on the results of x-ray diffraction, electron microscopy of microfibrils, and cellobiohydrolase I-gold labeling, we report the occurrence of cellulose biosynthesis in nine species representing three of the five sections of cyanobacteria. Sequence analysis of the genomes of four cyanobacteria revealed the presence of multiple amino acid sequences bearing the DDD35QXXRW motif conserved in all cellulose synthases. Pairwise alignments demonstrated that CesAs from plants were more similar to putative cellulose synthases from Anabaena sp. Pasteur Culture Collection 7120 and Nostoc punctiforme American Type Culture Collection 29133 than any other cellulose synthases in the database. Multiple alignments of putative cellulose synthases from Anabaena sp. Pasteur Culture Collection 7120 and N. punctiforme American Type Culture Collection 29133 with the cellulose synthases of other prokaryotes, Arabidopsis, Gossypium hirsutum, Populus alba × Populus tremula, corn (Zea mays), and Dictyostelium discoideum showed that cyanobacteria share an insertion between conserved regions U1 and U2 found previously only in eukaryotic sequences. Furthermore, phylogenetic analysis indicates that the cyanobacterial cellulose synthases share a common branch with CesAs of vascular plants in a manner similar to the relationship observed with cyanobacterial and chloroplast 16s rRNAs, implying endosymbiotic transfer of CesA from cyanobacteria to plants and an ancient origin for cellulose synthase in eukaryotes. PMID:11598227

Beneficial cyanobacteria and eubacteria synergistically enhance bioavailability of soil nutrients and yield of okra.

PubMed

Manjunath, Mallappa; Kanchan, Amrita; Ranjan, Kunal; Venkatachalam, Siddarthan; Prasanna, Radha; Ramakrishnan, Balasubramanian; Hossain, Firoz; Nain, Lata; Shivay, Yashbir Singh; Rai, Awadhesh Bahadur; Singh, Bijendra

2016-02-01

Microorganisms in the rhizosphere mediate the cycling of nutrients, their enhanced mobilisation and facilitate their uptake, leading to increased root growth, biomass and yield of plants. We examined the promise of beneficial cyanobacteria and eubacteria as microbial inoculants, applied singly or in combination as consortia or biofilms, to improve growth and yields of okra. Interrelationships among the microbial activities and the micro/macro nutrient dynamics in soils and okra yield characteristics were assessed along with the changes in the soil microbiome. A significant effect of microbial inoculation on alkaline phosphatase activity was recorded both at the mid-crop and harvest stages. Microbial biomass carbon values were highest due to the Anabaena sp. - Providencia sp. (CR1 + PR3) application. The yield of okra ranged from 444.6-478.4 g(-1) plant and a positive correlation (0.69) recorded between yield and root weight. The application of Azotobacter led to the highest root weight and yield. The concentration of Zn at mid-crop stage was 60-70% higher in the Azotobacter sp. and Calothrix sp. inoculated soils, as compared to uninoculated control. Iron concentration in soil was more than 2-3 folds higher than control at the mid-crop stage, especially due to the application of Anabaena-Azotobacter biofilm and Azotobacter sp. Both at the mid-crop and harvest stages, the PCR-DGGE profiles of eubacterial communities were similar among the uninoculated control, the Anabaena sp. - Providencia sp. (CW1 + PW5) and the Anabaena-Azotobacter biofilm treatments. Although the profiles of the Azotobacter, Calothrix and CR1 + PR3 treatments were identical at these stages of growth, the profile of CR1 + PR3 was clearly distinguishable. The performance of the inoculants, particularly Calothrix (T6) and consortium of Anabaena and Providencia (CR1 + PR3; T5), in terms of microbiological and nutrient data, along with generation of distinct PCR-DGGE profiles suggested their superiority and emphasized the utility of combining microbiological and molecular tools in the selection of effective microbial inoculants.

Sterling C. Robertson Dam and Limestone Lake on the Navasota River, Texas (Leon, Limestone and Robertson Counties).

DTIC Science & Technology

1976-04-01

Plicrocysti s sp. Synechococcus sp. Order Chamaesi phonal es Chamaesiphon sp. Order Hormogonal1es Anabaena sp. Anabaenopsis sp. Arthrospira sp...Sc-ytonerrn sp. Stig m rp. Spirulina sp. Kingdom Protista Phylum Euglenophyta (Euglenas) Order Euglenales Eugena sp. Phacus sp. Trache omonas sp

Amino Acid Transporters and Release of Hydrophobic Amino Acids in the Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120.

PubMed

Pernil, Rafael; Picossi, Silvia; Herrero, Antonia; Flores, Enrique; Mariscal, Vicente

2015-04-23

Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium that can use inorganic compounds such as nitrate or ammonium as nitrogen sources. In the absence of combined nitrogen, it can fix N2 in differentiated cells called heterocysts. Anabaena also shows substantial activities of amino acid uptake, and three ABC-type transporters for amino acids have been previously characterized. Seven new loci encoding predicted amino acid transporters were identified in the Anabaena genomic sequence and inactivated. Two of them were involved in amino acid uptake. Locus alr2535-alr2541 encodes the elements of a hydrophobic amino acid ABC-type transporter that is mainly involved in the uptake of glycine. ORF all0342 encodes a putative transporter from the dicarboxylate/amino acid:cation symporter (DAACS) family whose inactivation resulted in an increased uptake of a broad range of amino acids. An assay to study amino acid release from Anabaena filaments to the external medium was set up. Net release of the alanine analogue α-aminoisobutyric acid (AIB) was observed when transport system N-I (a hydrophobic amino acid ABC-type transporter) was engaged in the uptake of a specific substrate. The rate of AIB release was directly proportional to the intracellular AIB concentration, suggesting leakage from the cells by diffusion.

Ca2+ Requirement for Aerobic Nitrogen Fixation by Heterocystous Blue-Green Algae 1

PubMed Central

Rodríguez, Herminia; Rivas, Joaquín; Guerrero, Miguel G.; Losada, Manuel

1990-01-01

The requirement of Ca2+ for growth and nitrogen fixation has been investigated in two strains of heterocystous blue-green algae (Anabaena sp. and Anabaena ATCC 33047). With combined nitrogen (nitrate or ammonium) or with N2 under microaerobic conditions, Ca2+ was not required for growth, at least in concentrations greater than traces. In contrast, Ca2+ was required as a macronutrient for growth and nitrogen fixation with air as the nitrogen source. Addition of Ca2+ to an aerobic culture without Ca2+ promoted, after a lag of several hours, development of nitrogenase activity and cell growth. Provision of air to a microaerobic culture in the absence of Ca2+ promoted a drastic drop in nitrogenase activity, which rapidly recovered its initial level upon restoration of microaerobic conditions. Development of nitrogenase activity in response to either Ca2+ or low oxygen tension was dependent on de novo protein synthesis. The role of Ca2+ seems to be related to protection of nitrogenase from inactivation, by conferring heterocysts resistance to oxygen. PMID:16667401

Expression of Shewanella oneidensis MR-1 [FeFe]-Hydrogenase Genes in Anabaena sp. Strain PCC 7120

PubMed Central

Gärtner, Katrin; Lechno-Yossef, Sigal; Cornish, Adam J.; Wolk, C. Peter

2012-01-01

H2 generated from renewable resources holds promise as an environmentally innocuous fuel that releases only energy and water when consumed. In biotechnology, photoautotrophic oxygenic diazotrophs could produce H2 from water and sunlight using the cells' endogenous nitrogenases. However, nitrogenases have low turnover numbers and require large amounts of ATP. [FeFe]-hydrogenases found in other organisms can have 1,000-fold higher turnover numbers and no specific requirement for ATP but are very O2 sensitive. Certain filamentous cyanobacteria protect nitrogenase from O2 by sequestering the enzyme within internally micro-oxic, differentiated cells called heterocysts. We heterologously expressed the [FeFe]-hydrogenase operon from Shewanella oneidensis MR-1 in Anabaena sp. strain PCC 7120 using the heterocyst-specific promoter PhetN. Active [FeFe]-hydrogenase was detected in and could be purified from aerobically grown Anabaena sp. strain PCC 7120, but only when the organism was grown under nitrate-depleted conditions that elicited heterocyst formation. These results suggest that the heterocysts protected the [FeFe]-hydrogenase against inactivation by O2. PMID:23023750

Improved eco-friendly recombinant Anabaena sp. strain PCC7120 with enhanced nitrogen biofertilizer potential.

PubMed

Chaurasia, Akhilesh Kumar; Apte, Shree Kumar

2011-01-01

Photosynthetic, nitrogen-fixing Anabaena strains are native to tropical paddy fields and contribute to the carbon and nitrogen economy of such soils. Genetic engineering was employed to improve the nitrogen biofertilizer potential of Anabaena sp. strain PCC7120. Constitutive enhanced expression of an additional integrated copy of the hetR gene from a light-inducible promoter elevated HetR protein expression and enhanced functional heterocyst frequency in the recombinant strain. The recombinant strain displayed consistently higher nitrogenase activity than the wild-type strain and appeared to be in homeostasis with compatible modulation of photosynthesis and respiration. The enhanced combined nitrogen availability from the recombinant strain positively catered to the nitrogen demand of rice seedlings in short-term hydroponic experiments and supported better growth. The engineered strain is stable, eco-friendly, and useful for environmental application as nitrogen biofertilizer in paddy fields.

Improved Eco-Friendly Recombinant Anabaena sp. Strain PCC7120 with Enhanced Nitrogen Biofertilizer Potential▿

PubMed Central

Chaurasia, Akhilesh Kumar; Apte, Shree Kumar

2011-01-01

Photosynthetic, nitrogen-fixing Anabaena strains are native to tropical paddy fields and contribute to the carbon and nitrogen economy of such soils. Genetic engineering was employed to improve the nitrogen biofertilizer potential of Anabaena sp. strain PCC7120. Constitutive enhanced expression of an additional integrated copy of the hetR gene from a light-inducible promoter elevated HetR protein expression and enhanced functional heterocyst frequency in the recombinant strain. The recombinant strain displayed consistently higher nitrogenase activity than the wild-type strain and appeared to be in homeostasis with compatible modulation of photosynthesis and respiration. The enhanced combined nitrogen availability from the recombinant strain positively catered to the nitrogen demand of rice seedlings in short-term hydroponic experiments and supported better growth. The engineered strain is stable, eco-friendly, and useful for environmental application as nitrogen biofertilizer in paddy fields. PMID:21057013

Influence of temperature and UVR on photosynthesis and morphology of four species of cyanobacteria.

PubMed

Giordanino, M Valeria Fiorda; Strauch, Sebastian M; Villafañe, Virginia E; Helbling, E Walter

2011-04-04

During the late austral spring of 2009 we carried out experiments (4days of duration) with four cyanobacteria species, Anabaena sp., Nostoc sp., Arthrospira platensis and Microcystis sp., to assess the combined effects of temperature and solar radiation on photosynthesis performance and morphology. Two experimental temperatures (18°C and 23°C, simulating a 5°C increase under a scenario of climate change) and three radiation treatments (by using different filters/materials) were implemented: (i) P (PAR, 400-700nm), (ii) PA (PAR+UV-A, 320-700nm) and, (iii) PAB (PAR+UV-A+UV-B, 280-700nm). In general, samples under the P treatment had less decrease/higher recovery rates of effective photochemical quantum yield (Y) than those receiving UV-A or UV-A+UV-B. The effects of increased temperature were species-specific: At the end of the experiments, it was seen that increased temperature benefited photosynthetic performance of Anabaena sp. and Nostoc sp. but not of Microcystis sp. and A. platensis. Higher temperature was also associated to an increase in the chain area of Anabaena sp., and to bigger trichomes in A. platensis; however, no morphological effects were observed in Microcystis sp. In addition, in Nostoc sp. the increase in temperature counteracted the UVR impact on the reduction of the chain area. How these effects and mechanisms will affect the trophodynamics and production of aquatic ecosystems is still uncertain, but the specificity of the responses suggests that not all cyanobacteria would be equally benefited by temperature increases therefore affecting the balance and interaction among species in the water column. Copyright © 2011 Elsevier B.V. All rights reserved.

General distribution of the nitrogen control gene ntcA in cyanobacteria.

PubMed Central

Frías, J E; Mérida, A; Herrero, A; Martín-Nieto, J; Flores, E

1993-01-01

The ntcA gene from Synechococcus sp. strain PCC 7942 encodes a regulatory protein which is required for the expression of all of the genes known to be subject to repression by ammonium in that cyanobacterium. Homologs to ntcA have now been cloned by hybridization from the cyanobacteria Synechocystis sp. strain PCC 6803 and Anabaena sp. strain PCC 7120. Sequence analysis has shown that these ntcA genes would encode polypeptides strongly similar (77 to 79% identity) to the Synechococcus NtcA protein. Sequences hybridizing to ntcA have been detected in the genomes of nine other cyanobacteria that were tested, including strains of the genera Anabaena, Calothrix, Fischerella, Nostoc, Pseudoanabaena, Synechococcus, and Synechocystis. Images PMID:8366058

Overexpression of FurA in Anabaena sp. PCC 7120 reveals new targets for this regulator involved in photosynthesis, iron uptake and cellular morphology.

PubMed

González, Andrés; Bes, M Teresa; Barja, François; Peleato, M Luisa; Fillat, María F

2010-11-01

Previous genomic analyses of the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 have identified three ferric uptake regulator (Fur) homologs with low sequence identities and probably different functions in the cell. FurA is a constitutive protein that shares the highest homology with Fur from heterotrophic bacteria and appears to be essential for in vitro growth. In this study, we have analysed the effects of FurA overexpression on the Anabaena sp. phenotype and investigated which of the observed alterations were directly operated by FurA. Overexpression of the regulator led to changes in cellular morphology, resulting in shorter filaments with rounded cells of different sizes. The furA-overexpressing strain showed a slower photoautotrophic growth and a marked decrease in the oxygen evolution rate. Overexpression of the regulator also decreased both catalase and superoxide dismutase activities, but did not lead to an increase in the levels of intracellular reactive oxygen species. By combining phenotypic studies, reverse transcription-PCR analyses and electrophoretic mobility shift assays, we identified three novel direct targets of FurA, including genes encoding a siderophore outer membrane transporter (schT), bacterial actins (mreBCD) and the PSII reaction center protein D1 (psbA). The affinity of FurA for these novel targets was markedly affected by the absence of divalent metal ions, confirming previous evidence of a critical role for the metal co-repressor in the function of the regulator in vivo. The results unravel new cellular processes modulated by FurA, supporting its role as a global transcriptional regulator in Anabaena sp. PCC 7120.

[Partial biological characteristics and algicidal activity of an algicidal bacterium].

PubMed

Li, San-Hua; Zhang, Qi-Ya

2013-02-01

An algicidal bacterium was isolated from freshwater (Lake Donghu in Wuhan) and coded as A01. The morphology of the algicidal bacterium was observed using optical microscope and electron microscopes, the results showed that A01 was rod-shaped, approximately 1.5 microm in length and 0.45 microm in width and with no flagella structure. A01 was Gram-negative and belongs to the family Acinetobacter sp. though identification by Gram's staining and 16S rDNA gene analysis. A01 exhibited strong algicidal activity on the bloom-forming cyanobacterium Anabaena eucompacta under laboratory conditions. The removal rate of chlorophyll a after 7-day incubation with the culture supernatant of A01 and thalli were 77% and 61%, respectively. Microscopic observation showed that almost all cyanobacterial cells were destroyed within 3 d of co-incubation with the supernatant of algicidal bacterium, but a mass of the cyanobacterial cell lysis was observed only after 5 d of co-incubation with the thalli of algicidal bacterium. These results indicated that the main algicidal component of A01 was in its culture supernatant. In other words, the strain A01 could secrete algicidal component against Anabaena eucompacta.

The TolC-like protein HgdD of the cyanobacterium Anabaena sp. PCC 7120 is involved in secondary metabolite export and antibiotic resistance.

PubMed

Hahn, Alexander; Stevanovic, Mara; Mirus, Oliver; Schleiff, Enrico

2012-11-30

The role of TolC has largely been explored in proteobacteria, where it functions as a metabolite and protein exporter. In contrast, little research has been carried out on the function of cyanobacterial homologues, and as a consequence, not much is known about the mechanism of cyanobacterial antibiotic uptake and metabolite secretion in general. It has been suggested that the TolC-like homologue of the filamentous, heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, termed heterocyst glycolipid deposition protein D (HgdD), is involved in both protein and lipid secretion. To describe its function in secondary metabolite secretion, we established a system to measure the uptake of antibiotics based on the fluorescent molecule ethidium bromide. We analyzed the rate of porin-dependent metabolite uptake and confirmed the functional relation between detoxification and the action of HgdD. Moreover, we identified two major facilitator superfamily proteins that are involved in this process. It appears that anaOmp85 (Alr2269) is not required for insertion or assembly of HgdD, because an alr2269 mutant does not exhibit a phenotype similar to the hgdD mutant. Thus, we could assign components of the metabolite efflux system and describe parameters of detoxification by Anabaena sp. PCC 7120.

Impaired Photosynthesis in Phosphatidylglycerol-Deficient Mutant of Cyanobacterium Anabaena sp. PCC7120 with a Disrupted Gene Encoding a Putative Phosphatidylglycerophosphatase1

PubMed Central

Wu, Feng; Yang, Zhenle; Kuang, Tingyun

2006-01-01

Phosphatidylglycerol (PG) is a ubiquitous phospholipid in thylakoid membranes of cyanobacteria and chloroplasts and plays an important role in the structure and function of photosynthetic membranes. The last step of the PG biosynthesis is dephosphorylation of phosphatidylglycerophosphate (PGP) catalyzed by PGP phosphatase. However, the gene-encoding PGP phosphatase has not been identified and cloned from cyanobacteria or higher plants. In this study, we constructed a PG-deficient mutant from cyanobacterium Anabaena sp. PCC7120 with a disrupted gene (alr1715, a gene for Alr1715 protein, GenBank accession no. BAB78081) encoding a putative PGP phosphatase. The obtained mutant showed an approximately 30% reduction in the cellular content of PG. Following the reduction in the PG content, the photoautotrophical growth of the mutant was restrained, and the cellular content of chlorophyll was decreased. The decreases in net photosynthetic and photosystem II (PSII) activities on a cell basis also occurred in this mutant. Simultaneously, the photochemical efficiency of PSII was considerably declined, and less excitation energy was transferred toward PSII. These findings demonstrate that the alr1715 gene of Anabaena sp. PCC7120 is involved in the biosynthesis of PG and essential for photosynthesis. PMID:16815953

MreB is important for cell shape but not for chromosome segregation of the filamentous cyanobacterium Anabaena sp. PCC 7120.

PubMed

Hu, Bin; Yang, Guohua; Zhao, Weixing; Zhang, Yingjiao; Zhao, Jindong

2007-03-01

MreB is a bacterial actin that plays important roles in determination of cell shape and chromosome partitioning in Escherichia coli and Caulobacter crescentus. In this study, the mreB from the filamentous cyanobacterium Anabaena sp. PCC 7120 was inactivated. Although the mreB null mutant showed a drastic change in cell shape, its growth rate, cell division and the filament length were unaltered. Thus, MreB in Anabaena maintains cell shape but is not required for chromosome partitioning. The wild type and the mutant had eight and 10 copies of chromosomes per cell respectively. We demonstrated that DNA content in two daughter cells after cell division in both strains was not always identical. The ratios of DNA content in two daughter cells had a Gaussian distribution with a standard deviation much larger than a value expected if the DNA content in two daughter cells were identical, suggesting that chromosome partitioning is a random process. The multiple copies of chromosomes in cyanobacteria are likely required for chromosome random partitioning in cell division.

Different Functions of the Paralogs to the N-Terminal Domain of the Orange Carotenoid Protein in the Cyanobacterium Anabaena sp. PCC 71201[OPEN

PubMed Central

López-Igual, Rocío; Wilson, Adjélé; Bourcier de Carbon, Céline; Sutter, Markus; Turmo, Aiko

2016-01-01

The photoactive Orange Carotenoid Protein (OCP) is involved in cyanobacterial photoprotection. Its N-terminal domain (NTD) is responsible for interaction with the antenna and induction of excitation energy quenching, while the C-terminal domain is the regulatory domain that senses light and induces photoactivation. In most nitrogen-fixing cyanobacterial strains, there are one to four paralogous genes coding for homologs to the NTD of the OCP. The functions of these proteins are unknown. Here, we study the expression, localization, and function of these genes in Anabaena sp. PCC 7120. We show that the four genes present in the genome are expressed in both vegetative cells and heterocysts but do not seem to have an essential role in heterocyst formation. This study establishes that all four Anabaena NTD-like proteins can bind a carotenoid and the different paralogs have distinct functions. Surprisingly, only one paralog (All4941) was able to interact with the antenna and to induce permanent thermal energy dissipation. Two of the other Anabaena paralogs (All3221 and Alr4783) were shown to be very good singlet oxygen quenchers. The fourth paralog (All1123) does not seem to be involved in photoprotection. Structural homology modeling allowed us to propose specific features responsible for the different functions of these soluble carotenoid-binding proteins. PMID:27208286

Zur (FurB) is a key factor in the control of the oxidative stress response in Anabaena sp. PCC 7120.

PubMed

Sein-Echaluce, Violeta C; González, Andrés; Napolitano, Mauro; Luque, Ignacio; Barja, Francisco; Peleato, M Luisa; Fillat, María F

2015-06-01

Iron and zinc are necessary nutrients whose homeostasis is tightly controlled by members of the ferric uptake regulator (FUR) superfamily in the cyanobacterium Anabaena sp. PCC7120. Although the link between iron metabolism and oxidative stress management is well documented, little is known about the connection between zinc homeostasis and the oxidative stress response in cyanobacteria. Zinc homeostasis in Anabaena is controlled by Zur, also named FurB. When overexpressed in Escherichia coli, Zur (FurB) improved cell survival during oxidative stress. In order to investigate the possible correlation between Zur and the oxidative stress response in Anabaena, zur deletion and zur-overexpressing strains have been constructed, and the consequences of Zur imbalance evaluated. The lack of Zur increased sensitivity to hydrogen peroxide (H2 O2 ), whereas an excess of Zur enhanced oxidative stress resistance. Both mutants displayed pleiotropic phenotypes, including alterations on the filament surfaces observable by scanning electron microscopy, reduced content of endogenous H2 O2 and altered expression of sodA, catalases and several peroxiredoxins. Transcriptional and biochemical analyses unveiled that the appropriate level of Zur is required for proper control of the oxidative stress response and allowed us to identify major antioxidant enzymes as novel members of the Zur regulon. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

Site-specific recombination in the cyanobacterium Anabaena sp. strain PCC 7120 catalyzed by the integrase of coliphage HK022.

PubMed

Melnikov, Olga; Zaritsky, Arieh; Zarka, Aliza; Boussiba, Sammy; Malchin, Natalia; Yagil, Ezra; Kolot, Mikhail

2009-07-01

The integrase (Int) of the lambda-like coliphage HK022 catalyzes the site-specific integration and excision of the phage DNA into and from the chromosome of its host, Escherichia coli. Int recognizes two different pairs of recombining sites attP x attB and attL x attR for integration and excision, respectively. This system was adapted to the cyanobacterium Anabaena sp. strain PCC 7120 as a potential tool for site-specific gene manipulations in the cyanobacterium. Two plasmids were consecutively cointroduced by conjugation into Anabaena cells, one plasmid that expresses HK022 Int recombinase and the other plasmid that carries the excision substrate P(glnA)-attL-T1/T2-attR-lacZ, where T1/T2 are the strong transcription terminators of rrnB, to prevent expression of the lacZ reporter under the constitutive promoter P(glnA). The Int-catalyzed site-specific recombination reaction was monitored by the expression of lacZ emanating as a result of T1/T2 excision. Int catalyzed the site-specific excision reaction in Anabaena cells when its substrate was located either on the plasmid or on the chromosome with no need to supply an accessory protein, such as integration host factor and excisionase (Xis), which are indispensable for this reaction in its host, E. coli.

Variety of DNA Replication Activity Among Cyanobacteria Correlates with Distinct Respiration Activity in the Dark.

PubMed

Ohbayashi, Ryudo; Yamamoto, Jun-Ya; Watanabe, Satoru; Kanesaki, Yu; Chibazakura, Taku; Miyagishima, Shin-Ya; Yoshikawa, Hirofumi

2017-02-01

Cyanobacteria exhibit light-dependent cell growth since most of their cellular energy is obtained by photosynthesis. In Synechococcus elongatus PCC 7942, one of the model cyanobacteria, DNA replication depends on photosynthetic electron transport. However, the critical signal for the regulatory mechanism of DNA replication has not been identified. In addition, conservation of this regulatory mechanism has not been investigated among cyanobacteria. To understand this regulatory signal and its dependence on light, we examined the regulation of DNA replication under both light and dark conditions among three model cyanobacteria, S. elongatus PCC 7942, Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120. Interestingly, DNA replication activity in Synechocystis and Anabaena was retained when cells were transferred to the dark, although it was drastically decreased in S. elongatus. Glycogen metabolism and respiration were higher in Synechocystis and Anabaena than in S. elongatus in the dark. Moreover, DNA replication activity in Synechocystis and Anabaena was reduced to the same level as that in S. elongatus by inhibition of respiratory electron transport after transfer to the dark. These results demonstrate that there is disparity in DNA replication occurring in the dark among cyanobacteria, which is caused by the difference in activity of respiratory electron transport. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Functional Dependence between Septal Protein SepJ from Anabaena sp. Strain PCC 7120 and an Amino Acid ABC-Type Uptake Transporter.

PubMed

Escudero, Leticia; Mariscal, Vicente; Flores, Enrique

2015-08-01

In the diazotrophic filaments of heterocyst-forming cyanobacteria, two different cell types, the CO2-fixing vegetative cells and the N2-fixing heterocysts, exchange nutrients, including some amino acids. In the model organism Anabaena sp. strain PCC 7120, the SepJ protein, composed of periplasmic and integral membrane (permease) sections, is located at the intercellular septa joining adjacent cells in the filament. The unicellular cyanobacterium Synechococcus elongatus strain PCC 7942 bears a gene, Synpcc7942_1024 (here designated dmeA), encoding a permease homologous to the SepJ permease domain. Synechococcus strains lacking dmeA or lacking dmeA and expressing Anabaena sepJ were constructed. The Synechococcus dmeA mutant showed a significant 22 to 32% decrease in the uptake of aspartate, glutamate, and glutamine, a phenotype that could be partially complemented by Anabaena sepJ. Synechococcus mutants of an ATP-binding-cassette (ABC)-type transporter for polar amino acids showed >98% decreased uptake of glutamate irrespective of the presence of dmeA or Anabaena sepJ in the same strain. Thus, Synechococcus DmeA or Anabaena SepJ is needed to observe full (or close to full) activity of the ABC transporter. An Anabaena sepJ deletion mutant was significantly impaired in glutamate and aspartate uptake, which also in this cyanobacterium requires the activity of an ABC-type transporter for polar amino acids. SepJ appears therefore to generally stimulate the activity of cyanobacterial ABC-type transporters for polar amino acids. Conversely, an Anabaena mutant of three ABC-type transporters for amino acids was impaired in the intercellular transfer of 5-carboxyfluorescein, a SepJ-related property. Our results unravel possible functional interactions in transport elements important for diazotrophic growth. Membrane transporters are essential for many aspects of cellular life, from uptake and export of substances in unicellular organisms to intercellular molecular exchange in multicellular organisms. Heterocyst-forming cyanobacteria such as Anabaena represent a unique case of multicellularity, in which two cell types exchange nutrients and regulators. The SepJ protein located at the intercellular septa in the filaments of Anabaena contains a permease domain of the drug/metabolite transporter (DMT) superfamily that somehow contributes to intercellular molecular transfer. In this work, we have found that SepJ stimulates the activity of a polar amino acid uptake transporter of the ATP-binding-cassette (ABC) superfamily, which could itself affect an intercellular transfer activity related to SepJ, thus unraveling possible functional interactions between these different transporters. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

DNA Probes Show Genetic Variation in Cyanobacterial Symbionts of the Azolla Fern and a Closer Relationship to Free-Living Nostoc Strains than to Free-Living Anabaena Strains

PubMed Central

Plazinski, Jacek; Zheng, Qi; Taylor, Rona; Croft, Lynn; Rolfe, Barry G.; Gunning, Brian E. S.

1990-01-01

Twenty-two isolates of Anabaena azollae derived from seven Azolla species from various geographic and ecological sources were characterized by DNA-DNA hybridization. Cloned DNA fragments derived from the genomic sequences of three different A. azollae isolates were used to detect restriction fragment length polymorphism among all symbiotic anabaenas. DNA clones were radiolabeled and hybridized against southern blot transfers of genomic DNAs of different isolates of A. azollae digested with restriction endonucleases. Eight DNA probes were selected to identify the Anabaena strains tested. Two were strain specific and hybridized only to A. azollae strains isolated from Azolla microphylla or Azolla caroliniana. One DNA probe was section specific (hybridized only to anabaenas isolated from Azolla ferns representing the section Euazolla), and five other probes gave finer discrimination among anabaenas representing various ecotypes of Azolla species. These cloned genomic DNA probes identified 11 different genotypes of A. azollae isolates. These included three endosymbiotic genotypes within Azolla filiculoides species and two genotypes within both A. caroliniana and Azolla pinnata endosymbionts. Although we were not able to discriminate among anabaenas extracted from different ecotypes of Azolla nilotica, Azolla mexicina, Azolla rubra and Azolla microphylla species, each of the endosymbionts was easily identified as a unique genotype. When total DNA isolated from free-living Anabaena sp. strain PCC7120 was screened, none of the genomic DNA probes gave detectable positive hybridization. Total DNA of Nostoc cycas PCC7422 hybridized with six of eight genomic DNA fragments. These data imply that the dominant symbiotic organism in association with Azolla spp. is more closely related to Nostoc spp. than to free-living Anabaena spp. Images PMID:16348182

Crystallization, X-ray diffraction analysis and SIRAS/molecular-replacenent phasing of three crystal forms of Anabaena sensory rhodopsin transducer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogeley, Lutz; Luecke, Hartmut, E-mail: hudel@uci.edu

2006-04-01

Crystals of Anabaena sensory rhodopsin transducer, the transducer for the cyanobacterial photosensor Anabaena sensory rhodopsin, obtained in the space groups P4, C2 and P2{sub 1}2{sub 1}2{sub 1} diffract to 1.8, 2.1 and 2.0 Å, respectively. Phases for these crystal forms were obtained by SIRAS phasing using an iodide quick-soak derivative (P4) and molecular replacement (C2 and P2{sub 1}2{sub 1}2{sub 1}). Anabaena sensory rhodopsin transducer (ASRT) is a 14.7 kDa soluble signaling protein associated with the membrane-embedded light receptor Anabaena sensory rhodopsin (ASR) from Anabaena sp., a freshwater cyanobacterium. Crystals of ASRT were obtained in three different space groups, P4, C2more » and P2{sub 1}2{sub 1}2{sub 1}, which diffract to 1.8, 2.1 and 2.0 Å, respectively. Phases for one of these crystal forms (P4) were obtained by SIRAS phasing using an iodide quick-soak derivative and a partial model was built. Phases for the remaining crystal forms were obtained by molecular replacement using the partial model from the P4 crystal form.« less

The interplay between siderophore secretion and coupled iron and copper transport in the heterocyst-forming cyanobacterium Anabaena sp. PCC 7120.

PubMed

Nicolaisen, Kerstin; Hahn, Alexander; Valdebenito, Marianne; Moslavac, Suncana; Samborski, Anastazia; Maldener, Iris; Wilken, Corinna; Valladares, Ana; Flores, Enrique; Hantke, Klaus; Schleiff, Enrico

2010-11-01

Iron uptake is essential for Gram-negative bacteria including cyanobacteria. In cyanobacteria, however, the iron demand is higher than in proteobacteria due to the function of iron as a cofactor in photosynthesis and nitrogen fixation, but our understanding of iron uptake by cyanobacteria stands behind the knowledge in proteobacteria. Here, two genes involved in this process in the heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 were identified. ORF all4025 encodes SchE, a putative cytoplasmic membrane-localized transporter involved in TolC-dependent siderophore secretion. Inactivation of schE resulted in an enhanced sensitivity to high metal concentrations and decreased secretion of hydroxamate-type siderophores. ORF all4026 encodes a predicted outer membrane-localized TonB-dependent iron transporter, IacT. Inactivation of iacT resulted in decreased sensitivity to elevated iron and copper levels. Expression of iacT from the artificial trc promoter (P(trc)) resulted in sensitization against tested metals. Further analysis showed that iron and copper effects are synergistic because a decreased supply of iron induced a significant decrease of copper levels in the iacT insertion mutant but an increase of those levels in the strain carrying P(trc)-iacT. Our results unravel a link between iron and copper homeostasis in Anabaena sp. PCC 7120. Copyright © 2010 Elsevier B.V. All rights reserved.

A Comprehensively Curated Genome-Scale Two-Cell Model for the Heterocystous Cyanobacterium Anabaena sp. PCC 71201[CC-BY

PubMed Central

Steuer, Ralf

2017-01-01

Anabaena sp. PCC 7120 is a nitrogen-fixing filamentous cyanobacterium. Under nitrogen-limiting conditions, a fraction of the vegetative cells in each filament terminally differentiate to nongrowing heterocysts. Heterocysts are metabolically and structurally specialized to enable O2-sensitive nitrogen fixation. The functionality of the filament, as an association of vegetative cells and heterocysts, is postulated to depend on metabolic exchange of electrons, carbon, and fixed nitrogen. In this study, we compile and evaluate a comprehensive curated stoichiometric model of this two-cell system, with the objective function based on the growth of the filament under diazotrophic conditions. The predicted growth rate under nitrogen-replete and -deplete conditions, as well as the effect of external carbon and nitrogen sources, was thereafter verified. Furthermore, the model was utilized to comprehensively evaluate the optimality of putative metabolic exchange reactions between heterocysts and vegetative cells. The model suggested that optimal growth requires at least four exchange metabolites. Several combinations of exchange metabolites resulted in predicted growth rates that are higher than growth rates achieved by only considering exchange of metabolites previously suggested in the literature. The curated model of the metabolic network of Anabaena sp. PCC 7120 enhances our ability to understand the metabolic organization of multicellular cyanobacteria and provides a platform for further study and engineering of their metabolism. PMID:27899536

Impairment of ntcA gene revealed its role in regulating iron homeostasis, ROS production and cellular phenotype under iron deficiency in cyanobacterium Anabaena sp. PCC 7120.

PubMed

Kaushik, Manish Singh; Srivastava, Meenakshi; Singh, Anumeha; Mishra, Arun Kumar

2017-08-01

Iron deficiency ends up into several unavoidable consequences including damaging oxidative stress in cyanobacteria. NtcA is a global nitrogen regulator controls wide range of metabolisms in addition to regulation of nitrogen metabolism. In present communication, NtcA based regulation of iron homeostasis, ROS production and cellular phenotype under iron deficiency in Anabaena 7120 has been investigated. NtcA regulates the concentration dependent iron uptake by controlling the expression of furA gene. NtcA also regulated pigment synthesis and phenotypic alterations in Anabaena 7120. A significant increase in ROS production and corresponding reduction in the activities of antioxidative enzymes (SOD, CAT, APX and GR) in CSE2 mutant strain in contrast to wild type Anabaena 7120 also suggested the possible involvement of NtcA in protection against oxidative stress in iron deficiency. NtcA has no impact on the expression of furB and furC in spite of presence of consensus NtcA binding site (NBS) and -10 boxes in their promoter. NtcA also regulates the thylakoid arrangement as well as related photosynthetic and respiration rates under iron deficiency in Anabaena 7120. Overall results suggested that NtcA regulates iron acquisition and in turn protect Anabaena cells from the damaging effects of oxidative stress induced under iron deficiency.

Synergistic Effects of Nano-Sized Titanium Dioxide and Zinc on the Photosynthetic Capacity and Survival of Anabaena sp.

PubMed Central

Tang, Yulin; Li, Shuyan; Qiao, Junlian; Wang, Hongtao; Li, Lei

2013-01-01

Anabaena sp. was used to examine the toxicity of exposure to a nano-TiO2 suspension, Zn2+ solution, and mixtures of nano-TiO2 and Zn2+ suspensions. Typical chlorophyll fluorescence parameters, including effective quantum yield, photosynthetic efficiency and maximal electron transport rate, were measured by a pulse-amplitude modulated fluorometer. Nano-TiO2 particles exhibited no significant toxicity at concentrations lower than 10.0 mg/L. The 96 h concentration for the 50% maximal effect (EC50) of Zn2+ alone to Anabaena sp. was 0.38 ± 0.004 mg/L. The presence of nano-TiO2 at low concentrations (<1.0 mg/L) significantly enhanced the toxicity of Zn2+ and consequently reduced the EC50 value to 0.29 ± 0.003 mg/L. However, the toxicity of the Zn2+/TiO2 system decreased with increasing nano-TiO2 concentration because of the substantial adsorption of Zn2+ by nano-TiO2. The toxicity curve of the Zn2+/TiO2 system as a function of incremental nano-TiO2 concentrations was parabolic. The toxicity significantly increased at the initial stage, reached its maximum, and then decreased with increasing nano-TiO2 concentration. Hydrodynamic sizes, concentration of nano-TiO2 and Zn2+ loaded nano-TiO2 were the main parameters for synergistic toxicity. PMID:23852017

All0809/8/7 is a DevBCA-like ABC-type efflux pump required for diazotrophic growth in Anabaena sp. PCC 7120.

PubMed

Staron, Peter; Maldener, Iris

2012-10-01

Efflux pumps export a wide variety of proteinaceous and non-proteinaceous substrates across the Gram-negative cell wall. For the filamentous cyanobacterium Anabaena sp. strain PCC 7120, the ATP-driven glycolipid efflux pump DevBCA-TolC has been shown to be crucial for the differentiation of N(2)-fixing heterocysts from photosynthetically active vegetative cells. In this study, a homologous system was described. All0809/8/7-TolC form a typical ATP-driven efflux pump as shown by surface plasmon resonance. This putative exporter is also involved in diazotrophic growth of Anabaena sp. PCC 7120. A mutant in all0809 encoding the periplasmic membrane fusion protein of the pump was not able to grow without combined nitrogen. Although heterocysts of this mutant were not distinguishable from those of the wild-type in light and electron micrographs, they were impaired in providing the microoxic environment necessary for N(2) fixation. RT-PCR of all0809 transcripts and localization studies on All0807-GFP revealed that All0809/8/7 was initially downregulated during heterocyst maturation and upregulated at later stages of heterocyst formation in all cells of the filament. A substrate of the efflux pump could not be identified in ATP hydrolysis assays. We discuss a role for All0809/8/7-TolC in maintaining the continuous periplasm and how this would be of special importance for heterocyst differentiation.

Detection of Anatoxin-a and Three Analogs in Anabaena spp. Cultures: New Fluorescence Polarization Assay and Toxin Profile by LC-MS/MS

PubMed Central

Sanchez, Jon A.; Otero, Paz; Alfonso, Amparo; Ramos, Vitor; Vasconcelos, Vitor; Aráoz, Romulo; Molgó, Jordi; Vieytes, Mercedes R.; Botana, Luis M.

2014-01-01

Anatoxin-a (ATX) is a potent neurotoxin produced by several species of Anabaena spp. Cyanobacteria blooms around the world have been increasing in recent years; therefore, it is urgent to develop sensitive techniques that unequivocally confirm the presence of these toxins in fresh water and cyanobacterial samples. In addition, the identification of different ATX analogues is essential to later determine its toxicity. In this paper we designed a fluorescent polarization (FP) method to detect ATXs in water samples. A nicotinic acetylcholine receptor (nAChR) labeled with a fluorescein derivative was used to develop this assay. Data showed a direct relationship between the amount of toxin in a sample and the changes in the polarization degree of the emitted light by the labeled nAChR, indicating an interaction between the two molecules. This method was used to measure the amount of ATX in three Anabaena spp. cultures. Results indicate that it is a good method to show ATXs presence in algal samples. In order to check the toxin profile of Anabaena cultures a LC-MS/MS method was also developed. Within this new method, ATX-a, retention time (RT) 5 min, and three other molecules with a mass m/z 180.1 eluting at 4.14 min, 5.90 min and 7.14 min with MS/MS spectra characteristic of ATX toxin group not previously identified were detected in the Anabaena spp. cultures. These ATX analogues may have an important role in the toxicity of the sample. PMID:24469431

Characterization of the response to zinc deficiency in the cyanobacterium Anabaena sp. strain PCC 7120.

PubMed

Napolitano, Mauro; Rubio, Miguel Ángel; Santamaría-Gómez, Javier; Olmedo-Verd, Elvira; Robinson, Nigel J; Luque, Ignacio

2012-05-01

Zur regulators control zinc homeostasis by repressing target genes under zinc-sufficient conditions in a wide variety of bacteria. This paper describes how part of a survey of duplicated genes led to the identification of the open reading frame all2473 as the gene encoding the Zur regulator of the cyanobacterium Anabaena sp. strain PCC 7120. All2473 binds to DNA in a zinc-dependent manner, and its DNA-binding sequence was characterized, which allowed us to determine the relative contribution of particular nucleotides to Zur binding. A zur mutant was found to be impaired in the regulation of zinc homeostasis, showing sensitivity to elevated concentrations of zinc but not other metals. In an effort to characterize the Zur regulon in Anabaena, 23 genes containing upstream putative Zur-binding sequences were identified and found to be regulated by Zur. These genes are organized in six single transcriptional units and six operons, some of them containing multiple Zur-regulated promoters. The identities of genes of the Zur regulon indicate that Anabaena adapts to conditions of zinc deficiency by replacing zinc metalloproteins with paralogues that fulfill the same function but presumably with a lower zinc demand, and with inducing putative metallochaperones and membrane transport systems likely being involved in the scavenging of extracellular zinc, including plasma membrane ABC transport systems and outer membrane TonB-dependent receptors. Among the Zur-regulated genes, the ones showing the highest induction level encode proteins of the outer membrane, suggesting a primary role for components of this cell compartment in the capture of zinc cations from the extracellular medium.

Toxicity of volcanic-ash leachate to a blue-green alga. Results of a preliminary bioassay experiment

USGS Publications Warehouse

McKnight, Diane M.; Feder, G.L.; Stiles, E.A.

1981-01-01

To assess the possible effects of volcanic ash from the May 18,1980, eruption of Mt. St. Helens, Washington, on aquatic ecosystems, we conducted a bioassay experiment with a blue-green alga, Anabaena flos-aquae. Results showed that leachate (obtained by leaching 151 g of ash with 130 mL of simulated freshwater) was lethal to Anabaena flos-aquae cultures when diluted as much as 1:100 with culture medium. Cultures exposed to a 1:500 dilution grew, but a toxic effect was indicated by abnormalities in the Anabaena filaments. This study indicates that ash from the Mt. St. Helens volcano could have an effect on aquatic ecosystems in the areas of significant ashfall. Further study is needed to determine the toxic chemical constituents in the ash and also its possible effects on other aquatic organisms.

Regulation of intracellular free calcium concentration during heterocyst differentiation by HetR and NtcA in Anabaena sp. PCC 7120.

PubMed

Shi, Yunming; Zhao, Weixing; Zhang, Wei; Ye, Zi; Zhao, Jindong

2006-07-25

Calcium ions are important to some prokaryotic cellular processes, such as heterocyst differentiation of cyanobacteria. Intracellular free Ca(2+)concentration, [Ca(2+)](i), increases several fold in heterocysts and is regulated by CcbP, a Ca(2+)-binding protein found in heterocyst-forming cyanobacteria. We demonstrate here that CcbP is degraded by HetR, a serine-type protease that controls heterocyst differentiation. The degradation depends on Ca(2+) and appears to be specific because HetR did not digest other tested proteins. CcbP was found to bind two Ca(2+) per molecule with K(D) values of 200 nM and 12.8 microM. Degradation of CcbP releases bound Ca(2+) that contributes significantly to the increase of [Ca(2+)](i) during the process of heterocyst differentiation in Anabaena sp. strain PCC 7120. We suggest that degradation of CcbP is a mechanism of positive autoregulation of HetR. The down-regulation of ccbP in differentiating cells and mature heterocysts, which also is critical to the regulation of [Ca(2+)](i), depends on NtcA. Coexpression of ntcA and a ccbP promoter-controlled gfp in Escherichia coli diminished production of GFP, and the decrease is enhanced by alpha-ketoglutarate. It was also found that NtcA could bind a fragment of the ccbP promoter containing an NtcA-binding sequence in a alpha-ketoglutarate-dependent fashion. Therefore, [Ca(2+)](i) is regulated by a collaboration of HetR and NtcA in heterocyst differentiation in Anabaena sp. strain PCC 7120.

Regulation of intracellular free calcium concentration during heterocyst differentiation by HetR and NtcA in Anabaena sp. PCC 7120

PubMed Central

Shi, Yunming; Zhao, Weixing; Zhang, Wei; Ye, Zi; Zhao, Jindong

2006-01-01

Calcium ions are important to some prokaryotic cellular processes, such as heterocyst differentiation of cyanobacteria. Intracellular free Ca2+concentration, [Ca2+]i, increases several fold in heterocysts and is regulated by CcbP, a Ca2+-binding protein found in heterocyst-forming cyanobacteria. We demonstrate here that CcbP is degraded by HetR, a serine-type protease that controls heterocyst differentiation. The degradation depends on Ca2+ and appears to be specific because HetR did not digest other tested proteins. CcbP was found to bind two Ca2+ per molecule with KD values of 200 nM and 12.8 μM. Degradation of CcbP releases bound Ca2+ that contributes significantly to the increase of [Ca2+]i during the process of heterocyst differentiation in Anabaena sp. strain PCC 7120. We suggest that degradation of CcbP is a mechanism of positive autoregulation of HetR. The down-regulation of ccbP in differentiating cells and mature heterocysts, which also is critical to the regulation of [Ca2+]i, depends on NtcA. Coexpression of ntcA and a ccbP promoter-controlled gfp in Escherichia coli diminished production of GFP, and the decrease is enhanced by α-ketoglutarate. It was also found that NtcA could bind a fragment of the ccbP promoter containing an NtcA-binding sequence in a α-ketoglutarate-dependent fashion. Therefore, [Ca2+]i is regulated by a collaboration of HetR and NtcA in heterocyst differentiation in Anabaena sp. strain PCC 7120. PMID:16849429

Bioselective synthesis of gold nanoparticles from diluted mixed Au, Ir, and Rh ion solution by Anabaena cylindrica

NASA Astrophysics Data System (ADS)

Rochert, Anna S.; Rösken, Liz M.; Fischer, Christian B.; Schönleber, Andreas; Ecker, Dennis; van Smaalen, Sander; Geimer, Stefan; Wehner, Stefan

2017-11-01

Over the last years, an environmentally friendly and economically efficient way of nanoparticle production has been found in the biosynthesis of metal nanoparticles by bacteria and cyanobacteria. In this study, Anabaena cylindrica, a non-toxic cyanobacterium, is deployed in a diluted ionic aqueous mixture of equal concentrations of gold, iridium, and rhodium, of 0.1 mM each, for the selective biosynthesis of metal nanoparticles (NPs). To analyze the cyanobacterial metal uptake, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS) were applied. Only gold can be found in crystalline and nanoparticle form inside the cells of A. cylindrica, and it is the only metal for which ICP-MS analyses show a rapid decrease of the concentration in the culture medium. A slight decrease of rhodium and none of iridium was observed in the evaluated timeline of 51 h. The average diameter size of the emerging gold nanoparticles increased over the first few days, but is found to be below 10 nm even after more than 2 days. A new evaluation method was used to determine the spatially resolved distribution of the nanoparticles inside the cyanobacterial cells. This new method was also used to analyze TEM images from earlier studies of A. cylindrica and Anabaena sp., both incubated with an overall concentration of 0.8 mM Au3+ to compare the metal uptake. A. cylindrica was found to be highly selective towards the formation of gold nanoparticles in the presence of rhodium and iridium.

Transcription activation by NtcA and 2-oxoglutarate of three genes involved in heterocyst differentiation in the cyanobacterium Anabaena sp. strain PCC 7120.

PubMed

Valladares, Ana; Flores, Enrique; Herrero, Antonia

2008-09-01

In Anabaena sp. strain PCC 7120, differentiation of heterocysts takes place in response to the external cue of combined nitrogen deprivation, allowing the organism to fix atmospheric nitrogen in oxic environments. NtcA, a global transcriptional regulator of cyanobacteria, is required for activation of the expression of multiple genes involved in heterocyst differentiation, including key regulators that are specific to the process. We have set up a fully defined in vitro system, which includes the purified Anabaena RNA polymerase, and have studied the effects of NtcA and its signaling effector 2-oxoglutarate on RNA polymerase binding, open complex formation, and transcript production from promoters of the hetC, nrrA, and devB genes that are activated by NtcA at different stages of heterocyst differentiation. Both RNA polymerase and NtcA could specifically bind to the target DNA in the absence of any effector. 2-Oxoglutarate had a moderate positive effect on NtcA binding, and NtcA had a limited positive effect on RNA polymerase recruitment at the promoters. However, a stringent requirement of both NtcA and 2-oxoglutarate was observed for the detection of open complexes and transcript production at the three investigated promoters. These results support a key role for 2-oxoglutarate in transcription activation in the developing heterocyst.

Inactivation of agmatinase expressed in vegetative cells alters arginine catabolism and prevents diazotrophic growth in the heterocyst-forming cyanobacterium Anabaena.

PubMed

Burnat, Mireia; Flores, Enrique

2014-10-01

Arginine decarboxylase produces agmatine, and arginase and agmatinase are ureohydrolases that catalyze the production of ornithine and putrescine from arginine and agmatine, respectively, releasing urea. In the genome of the filamentous, heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120, ORF alr2310 putatively encodes an ureohydrolase. Cells of Anabaena supplemented with [(14) C]arginine took up and catabolized this amino acid generating a set of labeled amino acids that included ornithine, proline, and glutamate. In an alr2310 deletion mutant, an agmatine spot appeared and labeled glutamate increased with respect to the wild type, suggesting that Alr2310 is an agmatinase rather than an arginase. As determined in cell-free extracts, agmatinase activity could be detected in the wild type but not in the mutant. Thus, alr2310 is the Anabaena speB gene encoding agmatinase. The ∆alr2310 mutant accumulated large amounts of cyanophycin granule polypeptide, lacked nitrogenase activity, and did not grow diazotrophically. Growth tests in solid media showed that agmatine is inhibitory for Anabaena, especially under diazotrophic conditions, suggesting that growth of the mutant is inhibited by non-metabolized agmatine. Measurements of incorporation of radioactivity from [(14) C]leucine into macromolecules showed, however, a limited inhibition of protein synthesis in the ∆alr2310 mutant. Analysis of an Anabaena strain producing an Alr2310-GFP (green fluorescent protein) fusion showed expression in vegetative cells but much less in heterocysts, implying compartmentalization of the arginine decarboxylation pathway in the diazotrophic filaments of this heterocyst-forming cyanobacterium. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Requirement of Fra proteins for communication channels between cells in the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120.

PubMed

Omairi-Nasser, Amin; Mariscal, Vicente; Austin, Jotham R; Haselkorn, Robert

2015-08-11

The filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 differentiates specialized cells, heterocysts, that fix atmospheric nitrogen and transfer the fixed nitrogen to adjacent vegetative cells. Reciprocally, vegetative cells transfer fixed carbon to heterocysts. Several routes have been described for metabolite exchange within the filament, one of which involves communicating channels that penetrate the septum between adjacent cells. Several fra gene mutants were isolated 25 y ago on the basis of their phenotypes: inability to fix nitrogen and fragmentation of filaments upon transfer from N+ to N- media. Cryopreservation combined with electron tomography were used to investigate the role of three fra gene products in channel formation. FraC and FraG are clearly involved in channel formation, whereas FraD has a minor part. Additionally, FraG was located close to the cytoplasmic membrane and in the heterocyst neck, using immunogold labeling with antibody raised to the N-terminal domain of the FraG protein.

Factors affecting the photoproduction of ammonia from dinitrogen and water by the cyanobacterium Anabaena sp. strain ATCC 33047.

PubMed

Ramos, J L; Guerrero, M G; Losada, M

1987-04-01

Synthesis of ammonia from dinitrogen and water by suspensions of Anabaena sp. Strain ATCC 33047 treated with the glutamine synthetase inhibitor L-methionine-D,L-sulfoximine is strictly dependent on light. Under otherwise optimal conditions, the yield of ammonia production is influenced by irradiance, as well as by the density, depth, and turbulence of the cell suspension. The interaction among these factors seems to determine the actual amount of light available to each single cell or filament in the suspension for the photoproduction process. Under convenient illumination, the limiting factor in the synthesis of ammonia seems to be the cellular nitrogenase activity level, but under limiting light conditions the limiting factor could, however, be the assimilatory power required for nitrogen fixation. Photosynthetic ammonia production from atmospheric nitrogen and water can operate with an efficiency of ca. 10% of its theoretical maximum, representing a remarkable process for the conversion of light energy into chemical energy.

Specific Glucoside Transporters Influence Septal Structure and Function in the Filamentous, Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120.

PubMed

Nieves-Morión, Mercedes; Lechno-Yossef, Sigal; López-Igual, Rocío; Frías, José E; Mariscal, Vicente; Nürnberg, Dennis J; Mullineaux, Conrad W; Wolk, C Peter; Flores, Enrique

2017-04-01

When deprived of combined nitrogen, some filamentous cyanobacteria contain two cell types: vegetative cells that fix CO 2 through oxygenic photosynthesis and heterocysts that are specialized in N 2 fixation. In the diazotrophic filament, the vegetative cells provide the heterocysts with reduced carbon (mainly in the form of sucrose) and heterocysts provide the vegetative cells with combined nitrogen. Septal junctions traverse peptidoglycan through structures known as nanopores and appear to mediate intercellular molecular transfer that can be traced with fluorescent markers, including the sucrose analog esculin (a coumarin glucoside) that is incorporated into the cells. Uptake of esculin by the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 was inhibited by the α-glucosides sucrose and maltose. Analysis of Anabaena mutants identified components of three glucoside transporters that move esculin into the cells: GlsC (Alr4781) and GlsP (All0261) are an ATP-binding subunit and a permease subunit of two different ABC transporters, respectively, and HepP (All1711) is a major facilitator superfamily (MFS) protein that was shown previously to be involved in formation of the heterocyst envelope. Transfer of fluorescent markers (especially calcein) between vegetative cells of Anabaena was impaired by mutation of glucoside transporter genes. GlsP and HepP interact in bacterial two-hybrid assays with the septal junction-related protein SepJ, and GlsC was found to be necessary for the formation of a normal number of septal peptidoglycan nanopores and for normal subcellular localization of SepJ. Therefore, beyond their possible role in nutrient uptake in Anabaena , glucoside transporters influence the structure and function of septal junctions. IMPORTANCE Heterocyst-forming cyanobacteria have the ability to perform oxygenic photosynthesis and to assimilate atmospheric CO 2 and N 2 These organisms grow as filaments that fix these gases specifically in vegetative cells and heterocysts, respectively. For the filaments to grow, these types of cells exchange nutrients, including sucrose, which serves as a source of reducing power and of carbon skeletons for the heterocysts. Movement of sucrose between cells in the filament takes place through septal junctions and has been traced with a fluorescent sucrose analog, esculin, that can be taken up by the cells. Here, we identified α-glucoside transporters of Anabaena that mediate uptake of esculin and, notably, influence septal structure and the function of septal junctions. Copyright © 2017 American Society for Microbiology.

Specific Glucoside Transporters Influence Septal Structure and Function in the Filamentous, Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120

PubMed Central

Nieves-Morión, Mercedes; Lechno-Yossef, Sigal; López-Igual, Rocío; Frías, José E.; Mariscal, Vicente; Nürnberg, Dennis J.; Mullineaux, Conrad W.; Wolk, C. Peter

2017-01-01

ABSTRACT When deprived of combined nitrogen, some filamentous cyanobacteria contain two cell types: vegetative cells that fix CO2 through oxygenic photosynthesis and heterocysts that are specialized in N2 fixation. In the diazotrophic filament, the vegetative cells provide the heterocysts with reduced carbon (mainly in the form of sucrose) and heterocysts provide the vegetative cells with combined nitrogen. Septal junctions traverse peptidoglycan through structures known as nanopores and appear to mediate intercellular molecular transfer that can be traced with fluorescent markers, including the sucrose analog esculin (a coumarin glucoside) that is incorporated into the cells. Uptake of esculin by the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 was inhibited by the α-glucosides sucrose and maltose. Analysis of Anabaena mutants identified components of three glucoside transporters that move esculin into the cells: GlsC (Alr4781) and GlsP (All0261) are an ATP-binding subunit and a permease subunit of two different ABC transporters, respectively, and HepP (All1711) is a major facilitator superfamily (MFS) protein that was shown previously to be involved in formation of the heterocyst envelope. Transfer of fluorescent markers (especially calcein) between vegetative cells of Anabaena was impaired by mutation of glucoside transporter genes. GlsP and HepP interact in bacterial two-hybrid assays with the septal junction-related protein SepJ, and GlsC was found to be necessary for the formation of a normal number of septal peptidoglycan nanopores and for normal subcellular localization of SepJ. Therefore, beyond their possible role in nutrient uptake in Anabaena, glucoside transporters influence the structure and function of septal junctions. IMPORTANCE Heterocyst-forming cyanobacteria have the ability to perform oxygenic photosynthesis and to assimilate atmospheric CO2 and N2. These organisms grow as filaments that fix these gases specifically in vegetative cells and heterocysts, respectively. For the filaments to grow, these types of cells exchange nutrients, including sucrose, which serves as a source of reducing power and of carbon skeletons for the heterocysts. Movement of sucrose between cells in the filament takes place through septal junctions and has been traced with a fluorescent sucrose analog, esculin, that can be taken up by the cells. Here, we identified α-glucoside transporters of Anabaena that mediate uptake of esculin and, notably, influence septal structure and the function of septal junctions. PMID:28096449

Chemical and rheological properties of an extracellular polysaccharide produced by the cyanobacterium Anabaena sp. ATCC 33047.

PubMed

Moreno, J; Vargas, M A; Madiedo, J M; Muñoz, J; Rivas, J; Guerrero, M G

2000-02-05

The cyanobacterium (blue-green alga) Anabaena sp. ATCC 33047 produces an exopolysaccharide (EPS) during the stationary growth phase in batch culture. Chemical analysis of EPS revealed a heteropolysaccharidic nature, with xylose, glucose, galactose, and mannose the main neutral sugars found. The infrared (IR) spectrum of EPS showed absorption bands of carboxylate groups. The average molecular mass of the polymer was 1.35 MDa. Aqueous dispersions at EPS concentrations ranging from 0.2% to 0.6% (w/w) showed marked shear-thinning properties (power-law behavior). Linear dynamic viscoelastic properties showed that the elastic component was always higher than the viscous component. Viscous and viscoelastic properties demonstrated the absence of conformational changes within the concentration range studied. Stress-growth experiments revealed that 0.4% and 0.6% (w/w) EPS dispersions showed thixotropic properties. A detailed comparison of the linear dynamic viscoelasticity, transient flow, and decreasing shear rate flow curve properties was made for 0.4% (w/w) dispersions of xanthan gum (XG), Alkemir 110 (AG), and EPS. Viscoelastic spectra demonstrated that the EPS dispersion turned out to be more "fluidlike" than the AG and XG dispersions. The flow indexes indicated that the EPS dispersion was less shear-sensitive than that of XG, showing essentially the same viscosity, that is, >50 s(-1). The fact that viscosities of EPS and AG dispersions were not substantially different within the shear-rate range covered must be emphasized, in relation to EPS potential applications. The rheological behavior of EPS dispersions indicates the formation of an intermediate structure between a random-coil polysaccharide and a weak gel. Copyright 2000 John Wiley & Sons, Inc.

Selection and characterization of Euglena anabaena var. minor as a new candidate Euglena species for industrial application.

PubMed

Suzuki, Kengo; Mitra, Sharbanee; Iwata, Osamu; Ishikawa, Takahiro; Kato, Sueo; Yamada, Koji

2015-01-01

Euglena gracilis is a microalgae used as a model organism. Recently, mass cultivation of this species has been achieved for industrial applications. The genus Euglena includes more than 200 species that share common useful features, but the potential industrial applications of other Euglena species have not been evaluated. Thus, we conducted a pilot screening study to identify other species that proliferate at a sufficiently rapid rate to be used for mass cultivation; we found that Euglena anabaena var. minor had a rapid growth rate. In addition, its cells accumulated more than 40% weight of carbohydrate, most of which is considered to be a euglenoid specific type of beta-1-3-glucan, paramylon. Carbohydrate is stored in E. anabaena var. minor cells during normal culture, whereas E. gracilis requires nitrogen limitation to facilitate paramylon accumulation. These results suggest the potential industrial application of E. anabaena var. minor.

Bioinformatics evidence for the transfer of mycosporine-like amino acid core (4-deoxygadusol) synthesizing gene from cyanobacteria to dinoflagellates and an attempt to mutate the same gene (YP_324358) in Anabaena variabilis PCC 7937.

PubMed

Singh, Shailendra P; Häder, Donat-P; Sinha, Rajeshwar P

2012-06-01

We have identified a homologue of 4-deoxygadusol (core of mycosporine-like amino acids) synthesizing gene (ZP_05036788) from Synechococcus sp. PCC 7335 that was found to have additional functionally unknown N-terminal domain similar to homologues from dinoflagellates based on the ClustalW analysis. Phylogenetic analysis revealed that Synechococcus sp. (ZP_05036788) makes a clade together with dinoflagellates and was closest to the Oxyrrhis marina. This study shows for the first time that N-terminal additional sequences that possess upstream plastid targeting sequence in Heterocapsa triquetra and Karlodinium micrum were already evolved in cyanobacteria, and plastid targeting sequence were evolved later in dinoflagellates after divergence from chloroplast lacking Oxyrrhis marina. Thus, MAAs synthesizing genes were transferred from cyanobacteria to dinoflagellates and possibly Synechococcus sp. PCC 7335 acted as a donor during lateral gene transfer event. In addition, we also tried to mutate 4-deoxygadusol synthesizing gene (YP_324358) of Anabaena variabilis PCC 7937 by homologous recombination, however, all approaches to get complete segregation of the mutants from the wild-type were unsuccessful, showing the essentiality of YP_324358 for A. variabilis PCC 7937. Copyright © 2012 Elsevier B.V. All rights reserved.

Bioconversion of oil sludge into biomass of lipid metabolites for use as a source of biofuel

NASA Astrophysics Data System (ADS)

Shchemelinina, T. N.; Matistov, N. V.; Markarova, M. Yu; Anchugova, E. M.

2018-01-01

The possibilities for the generation of biofuel from the results of the accumulation of lipids in oil-contaminated environments were studied. This type of accumulation occurs in the biomass of yeast strains Rhodotorula sp. VKM Y-2993D; in bacteria like Pseudomonas libanensis B-3041D and in consortia of microalgal strains such as Acutodesmus obliquus Syko-A Ch-055-12, Chlorella sp. SYKO A Ch-011-10, Monoraphidium sp., and Anabaena sp. The most promising of these for processing petroleum hydrocarbons into biofuels was found to be the consortium of microalgal strains, the content of palmitic acid of which reached 49.0 %, thereby achieving a mid-range cetane number.

Overexpression of SepJ alters septal morphology and heterocyst pattern regulated by diffusible signals in Anabaena.

PubMed

Mariscal, Vicente; Nürnberg, Dennis J; Herrero, Antonia; Mullineaux, Conrad W; Flores, Enrique

2016-09-01

Filamentous, N2 -fixing, heterocyst-forming cyanobacteria grow as chains of cells that are connected by septal junctions. In the model organism Anabaena sp. strain PCC 7120, the septal protein SepJ is required for filament integrity, normal intercellular molecular exchange, heterocyst differentiation, and diazotrophic growth. An Anabaena strain overexpressing SepJ made wider septa between vegetative cells than the wild type, which correlated with a more spread location of SepJ in the septa as observed with a SepJ-GFP fusion, and contained an increased number of nanopores, the septal peptidoglycan perforations that likely accommodate septal junctions. The septa between heterocysts and vegetative cells, which are narrow in wild-type Anabaena, were notably enlarged in the SepJ-overexpressing mutant. Intercellular molecular exchange tested with fluorescent tracers was increased for the SepJ-overexpressing strain specifically in the case of calcein transfer between vegetative cells and heterocysts. These results support an association between calcein transfer, SepJ-related septal junctions, and septal peptidoglycan nanopores. Under nitrogen deprivation, the SepJ-overexpressing strain produced an increased number of contiguous heterocysts but a decreased percentage of total heterocysts. These effects were lost or altered in patS and hetN mutant backgrounds, supporting a role of SepJ in the intercellular transfer of regulatory signals for heterocyst differentiation. © 2016 John Wiley & Sons Ltd.

The heterocyst differentiation transcriptional regulator HetR of the filamentous cyanobacterium Anabaena forms tetramers and can be regulated by phosphorylation.

PubMed

Valladares, Ana; Flores, Enrique; Herrero, Antonia

2016-02-01

Many filamentous cyanobacteria respond to the external cue of nitrogen scarcity by the differentiation of heterocysts, cells specialized in the fixation of atmospheric nitrogen in oxic environments. Heterocysts follow a spatial pattern along the filament of two heterocysts separated by ca. 10-15 vegetative cells performing oxygenic photosynthesis. HetR is a transcriptional regulator that directs heterocyst differentiation. In the model strain Anabaena sp. PCC 7120, the HetR protein was observed in various oligomeric forms in vivo, including a tetramer that peaked with maximal hetR expression during differentiation. Tetramers were not detected in a hetR point mutant incapable of differentiation, but were conspicuous in an over-differentiating strain lacking the PatS inhibitor. In differentiated filaments the HetR tetramer was restricted to heterocysts, being undetectable in vegetative cells. HetR co-purified with RNA polymerase from Anabaena mainly as a tetramer. In vitro, purified recombinant HetR was distributed between monomers, dimers, trimers and tetramers, and it was phosphorylated when incubated with (γ-(32)P)ATP. Phosphorylation and PatS hampered the accumulation of HetR tetramers and impaired HetR binding to DNA. In summary, tetrameric HetR appears to represent a functionally relevant form of HetR, whose abundance in the Anabaena filament could be negatively regulated by phosphorylation and by PatS. © 2015 John Wiley & Sons Ltd.

Solar energy conversion through biophotolysis. Final report, April 1, 1977-March 31, 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benemann, J.R.; Hallenbeck, P.C.; Murry, M.A.

Biophotolysis has been demonstrated using nitrogen-starved cultures of the blue-green alga Anabaena cylindrica. Individual chapters are devoted to: a review of literature on hydrogen from algae; development of the biophotolysis system; thermophilic blue-green algae; characterization and partial purification of the reversible hydrogenase; purification and properties of nitrogenase; studies with an antibody specific to nitrogenase; nitrogenase regulation in Anabaena cylindrica; and hydrogen production with photosynthetic bacteria.

Specific role of the cyanobacterial PipX factor in the heterocysts of Anabaena sp. strain PCC 7120.

PubMed

Valladares, Ana; Rodríguez, Virginia; Camargo, Sergio; Martínez-Noël, Giselle M A; Herrero, Antonia; Luque, Ignacio

2011-03-01

The PipX factor is a regulatory protein that seems to occur only in cyanobacteria. In the filamentous, heterocyst-forming Anabaena sp. strain PCC 7120, open reading frame (ORF) asr0485, identified as the pipX gene, is expressed mainly under conditions of combined-nitrogen deprivation dependent on the global N regulator NtcA and the heterocyst-specific regulator HetR. Primer extension and 5' rapid amplification of cDNA ends (RACE) analyses detected three transcription start points corresponding to a canonical NtcA-activated promoter (to which direct binding of NtcA was observed), an NtcA- and HetR-dependent promoter, and a consensus-type promoter, the last with putative -35 and -10 determinants. Activation of pipX took place in cells differentiating into heterocysts at intermediate to late stages of the process. Accordingly, disruption of pipX led to impaired diazotrophic growth, reduced nitrogenase activity, and impaired activation of the nitrogenase structural genes. The nitrogenase activity of the mutant was low under oxic conditions, likely resulting from inefficient protection against oxygen. In line with this, the activation of the coxB2A2C2 and coxB3A3C3 operons, encoding heterocyst-specific terminal respiratory oxidases responsible for internal oxygen removal, was deficient in the pipX mutant. Therefore, the Anabaena PipX factor shows a spatiotemporal specificity contributing to normal heterocyst function, including full activation of the nitrogenase structural genes and genes of the nitrogenase-protective features of the heterocyst.

NADPH-Thioredoxin Reductase C Mediates the Response to Oxidative Stress and Thermotolerance in the Cyanobacterium Anabaena sp. PCC7120.

PubMed

Sánchez-Riego, Ana M; Mata-Cabana, Alejandro; Galmozzi, Carla V; Florencio, Francisco J

2016-01-01

NADPH-thioredoxin reductase C (NTRC) is a bimodular enzyme composed of an NADPH-thioredoxin reductase and a thiioredoxin domain extension in the same protein. In plants, NTRC has been described to be involved in the protection of the chloroplast against oxidative stress damage through reduction of the 2-Cys peroxiredoxin (2-Cys Prx) as well as through other functions related to redox enzyme regulation. In cyanobacteria, the Anabaena NTRC has been characterized in vitro, however, nothing was known about its in vivo function. In order to study that, we have generated the first knockout mutant strain (ΔntrC), apart from the previously described in Arabidopsis. Detailed characterization of this strain reveals a differential sensitivity to oxidative stress treatments with respect to the wild-type Anabaena strain, including a higher level of ROS (reactive oxygen species) in normal growth conditions. In the mutant strain, different oxidative stress treatments such as hydrogen peroxide, methyl-viologen or high light irradiance provoke an increase in the expression of genes related to ROS detoxification, including AnNTRC and peroxiredoxin genes, with a concomitant increase in the amount of AnNTRC and 2-Cys Prx. Moreover, the role of AnNTRC in the antioxidant response is confirmed by the observation of a pronounced overoxidation of the 2-Cys Prx and a time-delay recovery of the reduced form of this protein upon oxidative stress treatments. Our results suggest the participation of this enzyme in the peroxide detoxification in Anabaena. In addition, we describe the role of Anabaena NTRC in thermotolerance, by the appearance of high molecular mass AnNTRC complexes, showing that the mutant strain is more sensitive to high temperature treatments.

Increased heterocyst frequency by patN disruption in Anabaena leads to enhanced photobiological hydrogen production at high light intensity and high cell density.

PubMed

Masukawa, Hajime; Sakurai, Hidehiro; Hausinger, Robert P; Inoue, Kazuhito

2017-03-01

The effects of increasing the heterocyst-to-vegetative cell ratio on the nitrogenase-based photobiological hydrogen production by the filamentous heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 were studied. Using the uptake hydrogenase-disrupted mutant (ΔHup) as the parent, a deletion-insertion mutant (PN1) was created in patN, known to be involved in heterocyst pattern formation and leading to multiple singular heterocysts (MSH) in Nostoc punctiforme strain ATCC 29133. The PN1 strain showed heterocyst differentiation but failed to grow in medium free of combined-nitrogen; however, a spontaneous mutant (PN22) was obtained on prolonged incubation of PN1 liquid cultures and was able to grow robustly on N 2 . The disruption of patN was confirmed in both PN1 and PN22 by PCR and whole genome resequencing. Under combined-nitrogen limitation, the percentage of heterocysts to total cells in the PN22 filaments was 13-15 and 16-18% under air and 1% CO 2 -enriched air, respectively, in contrast to the parent ΔHup which formed 6.5-11 and 9.7-13% heterocysts in these conditions. The PN22 strain exhibited a MSH phenotype, normal diazotrophic growth, and higher H 2 productivity at high cell concentrations, and was less susceptible to photoinhibition by strong light than the parent ΔHup strain, resulting in greater light energy utilization efficiency in H 2 production on a per unit area basis under high light conditions. The increase in MSH frequency shown here appears to be a viable strategy for enhancing H 2 productivity by outdoor cultures of cyanobacteria in high-light environments.

Demonstration of a sensory rhodopsin in eubacteria.

PubMed

Jung, Kwang-Hwan; Trivedi, Vishwa D; Spudich, John L

2003-03-01

We report the first sensory rhodopsin observed in the eubacterial domain, a green light-activated photoreceptor in Anabaena (Nostoc) sp. PCC7120, a freshwater cyanobacterium. The gene encoding the membrane opsin protein of 261 residues (26 kDa) and a smaller gene encoding a soluble protein of 125 residues (14 kDa) are under the same promoter in a single operon. The opsin expressed heterologously in Escherichia coli membranes bound all-trans retinal to form a pink pigment (lambda max 543 nm) with a photochemical reaction cycle of 110 ms half-life (pH 6.8, 18 degrees C). Co-expression with the 14 kDa protein increased the rate of the photocycle, indicating physical interaction with the membrane-embedded rhodopsin, which we confirmed in vitro by affinity enrichment chromatography and Biacore interaction. The pigment lacks the proton donor carboxylate residue in helix C conserved in known retinylidene proton pumps and did not exhibit detectable proton ejection activity. We detected retinal binding to the protein in Anabaena membranes by SDS-PAGE and autofluorography of 3H-labelled all-trans retinal of reduced membranes from the organism. We conclude that Anabaena rhodopsin functions as a photosensory receptor in its natural environment, and suggest that the soluble 14 kDa protein transduces a signal from the receptor. Therefore, unlike the archaeal sensory rhodopsins, which transmit signals by transmembrane helix-helix interactions with membrane-embedded transducers, the Anabaena sensory rhodopsin may signal through a soluble cytoplasmic protein, analogous to higher animal visual pigments.

Toxicokinetics of Microcystin and Dihydro-Microcystin in Swine

DTIC Science & Technology

1994-05-14

cyanobacteria (blue-green algae) including, Nicrocystis, Anabaena, Nostoc , and Oscillatoria, produce cyclic heptapeptida hepatotoxins that have been termed...1990) describe three hepatotoxic MCs from Nostoc spp. which retained toxicity similar to MCLR despite the fact that they contained an acetoxyl group...W. W. (1990) Structures of three new cyclic hepatapeptide hepatotoxins produced by the cyanobacterium (blue-green algae) Nostoc sp. Strain 152. J

Calcium impacts carbon and nitrogen balance in the filamentous cyanobacterium Anabaena sp. PCC 7120

PubMed Central

Walter, Julia; Lynch, Fiona; Battchikova, Natalia; Aro, Eva-Mari

2016-01-01

Calcium is integral to the perception, communication and adjustment of cellular responses to environmental changes. However, the role of Ca2+ in fine-tuning cellular responses of wild-type cyanobacteria under favourable growth conditions has not been examined. In this study, extracellular Ca2+ has been altered, and changes in the whole transcriptome of Anabaena sp. PCC 7120 have been evaluated under conditions replete of carbon and combined nitrogen. Ca2+ induced differential expression of many genes driving primary cellular metabolism, with transcriptional regulation of carbon- and nitrogen-related processes responding with opposing trends. However, physiological effects of these transcriptional responses on biomass accumulation, biomass composition, and photosynthetic activity over the 24h period following Ca2+ adjustment were found to be minor. It is well known that intracellular carbon:nitrogen balance is integral to optimal cell growth and that Ca2+ plays an important role in the response of heterocystous cyanobacteria to combined-nitrogen deprivation. This work adds to the current knowledge by demonstrating a signalling role of Ca2+ for making sensitive transcriptional adjustments required for optimal growth under non-limiting conditions. PMID:27012282

Calcium impacts carbon and nitrogen balance in the filamentous cyanobacterium Anabaena sp. PCC 7120.

PubMed

Walter, Julia; Lynch, Fiona; Battchikova, Natalia; Aro, Eva-Mari; Gollan, Peter J

2016-06-01

Calcium is integral to the perception, communication and adjustment of cellular responses to environmental changes. However, the role of Ca(2+) in fine-tuning cellular responses of wild-type cyanobacteria under favourable growth conditions has not been examined. In this study, extracellular Ca(2+) has been altered, and changes in the whole transcriptome of Anabaena sp. PCC 7120 have been evaluated under conditions replete of carbon and combined nitrogen. Ca(2+) induced differential expression of many genes driving primary cellular metabolism, with transcriptional regulation of carbon- and nitrogen-related processes responding with opposing trends. However, physiological effects of these transcriptional responses on biomass accumulation, biomass composition, and photosynthetic activity over the 24h period following Ca(2+) adjustment were found to be minor. It is well known that intracellular carbon:nitrogen balance is integral to optimal cell growth and that Ca(2+) plays an important role in the response of heterocystous cyanobacteria to combined-nitrogen deprivation. This work adds to the current knowledge by demonstrating a signalling role of Ca(2+) for making sensitive transcriptional adjustments required for optimal growth under non-limiting conditions. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Developmental rearrangement of cyanobacterial nif genes: nucleotide sequence, open reading frames, and cytochrome P-450 homology of the Anabaena sp. strain PCC 7120 nifD element.

PubMed Central

Lammers, P J; McLaughlin, S; Papin, S; Trujillo-Provencio, C; Ryncarz, A J

1990-01-01

An 11-kbp DNA element of unknown function interrupts the nifD gene in vegetative cells of Anabaena sp. strain PCC 7120. In developing heterocysts the nifD element excises from the chromosome via site-specific recombination between short repeat sequences that flank the element. The nucleotide sequence of the nifH-proximal half of the element was determined to elucidate the genetic potential of the element. Four open reading frames with the same relative orientation as the nifD element-encoded xisA gene were identified in the sequenced region. Each of the open reading frames was preceded by a reasonable ribosome-binding site and had biased codon utilization preferences consistent with low levels of expression. Open reading frame 3 was highly homologous with three cytochrome P-450 omega-hydroxylase proteins and showed regional homology to functionally significant domains common to the cytochrome P-450 superfamily. The sequence encoding open reading frame 2 was the most highly conserved portion of the sequenced region based on heterologous hybridization experiments with three genera of heterocystous cyanobacteria. Images PMID:2123860

CyDiv, a Conserved and Novel Filamentous Cyanobacterial Cell Division Protein Involved in Septum Localization.

PubMed

Mandakovic, Dinka; Trigo, Carla; Andrade, Derly; Riquelme, Brenda; Gómez-Lillo, Gabriela; Soto-Liebe, Katia; Díez, Beatriz; Vásquez, Mónica

2016-01-01

Cell division in bacteria has been studied mostly in Escherichia coli and Bacillus subtilis, model organisms for Gram-negative and Gram-positive bacteria, respectively. However, cell division in filamentous cyanobacteria is poorly understood. Here, we identified a novel protein, named CyDiv (Cyanobacterial Division), encoded by the all2320 gene in Anabaena sp. PCC 7120. We show that CyDiv plays a key role during cell division. CyDiv has been previously described only as an exclusive and conserved hypothetical protein in filamentous cyanobacteria. Using polyclonal antibodies against CyDiv, we showed that it localizes at different positions depending on cell division timing: poles, septum, in both daughter cells, but also in only one of the daughter cells. The partial deletion of CyDiv gene generates partial defects in cell division, including severe membrane instability and anomalous septum localization during late division. The inability to complete knock out CyDiv strains suggests that it is an essential gene. In silico structural protein analyses and our experimental results suggest that CyDiv is an FtsB/DivIC-like protein, and could therefore, be part of an essential late divisome complex in Anabaena sp. PCC 7120.

Classification and phylogeny of the cyanobiont Anabaena azollae Strasburger: an answered question?

PubMed

Pereira, Ana L; Vasconcelos, Vitor

2014-06-01

The symbiosis Azolla-Anabaena azollae, with a worldwide distribution in pantropical and temperate regions, is one of the most studied, because of its potential application as a biofertilizer, especially in rice fields, but also as an animal food and in phytoremediation. The cyanobiont is a filamentous, heterocystic cyanobacterium that inhabits the foliar cavities of the pteridophyte and the indusium on the megasporocarp (female reproductive structure). The classification and phylogeny of the cyanobiont is very controversial: from its morphology, it has been named Nostoc azollae, Anabaena azollae, Anabaena variabilis status azollae and recently Trichormus azollae, but, from its 16S rRNA gene sequence, it has been assigned to Nostoc and/or Anabaena, and from its phycocyanin gene sequence, it has been assigned as non-Nostoc and non-Anabaena. The literature also points to a possible co-evolution between the cyanobiont and the Azolla host, since dendrograms and phylogenetic trees of fatty acids, short tandemly repeated repetitive (STRR) analysis and restriction fragment length polymorphism (RFLP) analysis of nif genes and the 16S rRNA gene give a two-cluster association that matches the two-section ranking of the host (Azolla). Another controversy surrounds the possible existence of more than one genus or more than one species strain. The use of freshly isolated or cultured cyanobionts is an additional problem, since their morphology and protein profiles are different. This review gives an overview of how morphological, chemical and genetic analyses influence the classification and phylogeny of the cyanobiont and future research. © 2014 IUMS.

Identification of a common cyanobacterial symbiont associated with Azolla spp. through molecular and morphological characterization of free-living and symbiotic cyanobacteria.

PubMed Central

Gebhardt, J S; Nierzwicki-Bauer, S A

1991-01-01

Symbiotically associated cyanobacteria from Azolla mexicana and Azolla pinnata were isolated and cultured in a free-living state. Morphological analyses revealed differences between the free-living isolates and their symbiotic counterparts, as did restriction fragment length polymorphism (RFLP) analyses with both single-copy glnA and rbcS gene probes and a multicopy psbA gene probe. RFLP analyses with Anabaena sp. strain PCC 7120 nifD excision element probes, including an xisA gene probe, detected homologous sequences in DNA extracted from the free-living isolates. Sequences homologous to these probes were not detected in DNA from the symbiotically associated cyanobacteria. These analyses indicated that the isolates were not identical to the major cyanobacterial symbiont species residing in leaf cavities of Azolla spp. Nevertheless, striking similarities between several free-living isolates were observed. In every instance, the isolate from A. pinnata displayed banding patterns virtually identical to those of free-living cultures previously isolated from Azolla caroliniana and Azolla filiculoides. These results suggest the ubiquitous presence of a culturable minor cyanobacterial symbiont in at least three species of Azolla. Images PMID:1685078

Recent developments in therapeutic applications of Cyanobacteria.

PubMed

Raja, Rathinam; Hemaiswarya, Shanmugam; Ganesan, Venkatesan; Carvalho, Isabel S

2016-05-01

The cyanobacteria (blue-green algae) are photosynthetic prokaryotes having applications in human health with numerous biological activities and as a dietary supplement. It is used as a food supplement because of its richness in nutrients and digestibility. Many cyanobacteria (Microcystis sp, Anabaena sp, Nostoc sp, Oscillatoria sp., etc.) produce a great variety of secondary metabolites with potent biological activities. Cyanobacteria produce biologically active and chemically diverse compounds belonging to cyclic peptides, lipopeptides, fatty acid amides, alkaloids and saccharides. More than 50% of the marine cyanobacteria are potentially exploitable for extracting bioactive substances which are effective in killing cancer cells by inducing apoptotic death. Their role as anti-viral, anti-tumor, antimicrobial, anti-HIV and a food additive have also been well established. However, such products are at different stages of clinical trials and only a few compounds have reached to the market.

Robust stochastic Turing patterns in the development of a one-dimensional cyanobacterial organism.

PubMed

Di Patti, Francesca; Lavacchi, Laura; Arbel-Goren, Rinat; Schein-Lubomirsky, Leora; Fanelli, Duccio; Stavans, Joel

2018-05-01

Under nitrogen deprivation, the one-dimensional cyanobacterial organism Anabaena sp. PCC 7120 develops patterns of single, nitrogen-fixing cells separated by nearly regular intervals of photosynthetic vegetative cells. We study a minimal, stochastic model of developmental patterns in Anabaena that includes a nondiffusing activator, two diffusing inhibitor morphogens, demographic fluctuations in the number of morphogen molecules, and filament growth. By tracking developing filaments, we provide experimental evidence for different spatiotemporal roles of the two inhibitors during pattern maintenance and for small molecular copy numbers, justifying a stochastic approach. In the deterministic limit, the model yields Turing patterns within a region of parameter space that shrinks markedly as the inhibitor diffusivities become equal. Transient, noise-driven, stochastic Turing patterns are produced outside this region, which can then be fixed by downstream genetic commitment pathways, dramatically enhancing the robustness of pattern formation, also in the biologically relevant situation in which the inhibitors' diffusivities may be comparable.

Time-dependent growth of crystalline Au0-nanoparticles in cyanobacteria as self-reproducing bioreactors: 1. Anabaena sp.

NASA Astrophysics Data System (ADS)

Rösken, Liz M.; Körsten, Susanne; Fischer, Christian B.; Schönleber, Andreas; van Smaalen, Sander; Geimer, Stefan; Wehner, Stefan

2014-04-01

Customized metal nanoparticles are highly relevant in industrial processes, where they are used as catalysts and therefore needed on a large scale. An extremely economically and environmentally friendly way to produce metal nanoparticles is microbial biosynthesis, meaning the biosorption and bioreduction of diluted metal ions to zero valent (metal) nanoparticles. To maintain the key advantage of biosynthesis, including eco friendliness, a bioreactor (e.g., bacteria) has to be harmless by itself. Here, the ability of the cyanobacteria Anabaena sp. (SAG 12.82) is shown to fulfill both needs: bioreduction of Au3+ ions to Au0 and the subsequent formation of crystalline Au0-nanoparticles as well as absence of the release of toxic substances (e.g., anatoxin-a). The time-dependent growth of the nanoparticles is recorded by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) over a range of several days. Formation of nanoparticles starts within the first minutes at the heterocyst polysaccharide layer (HEP). After 4 h, the dominating amount of nanoparticles is found in the vegetative cells. The bioproduced nanoparticles are found in both cell types, mainly located along the thylakoid membranes of the vegetative cells and have a final average size of 9 nm within the examined timescale of a few days.

Azolla filiculoides Nitrogenase Activity Decrease Induced by Inoculation with Chlamydomonas sp. †

PubMed Central

Habte, Mitiku

1986-01-01

Experiments were conducted to determine the influence of Chlamydomonas sp. on nitrogen fixation (C2H2 → C2H4) in Azolla filiculoides and on the nitrogen fixation and growth of free-living Anabaena azollae 2B organisms. Inoculation of azolla medium with Chlamydomonas sp. was associated with decreased nitrogenase activity in A. filiculoides and with increases in the density of a fungal population identified as Acremonium sp. Subsequent inoculation of azolla medium with this fungus was also accompanied by a significant decrease in nitrogenase activity of A. filiculoides. However, the extent of depression of nitrogenase activity was significantly higher when azolla medium was inoculated with Chlamydomonas sp. than when it was inoculated with Acremonium sp. Inoculation of nitrogen-free Stanier medium with either Acremonium sp. or Chlamydomonas sp. did not adversely affect the growth or nitrogenase activity of free-living A. azollae. Decreased nitrogenase activity in A. filiculoides is apparently related to the adverse influence of the green alga and the fungus on the macrosymbiont. The mechanisms that might be involved are discussed. PMID:16347211

Characterization of Co-Cultivation of Cyanobacteria on Growth, Productions of Polysaccharides and Extracellular Proteins, Nitrogenase Activity, and Photosynthetic Activity.

PubMed

Xue, Chuizhao; Wang, Libo; Wu, Tong; Zhang, Shiping; Tang, Tao; Wang, Liang; Zhao, Quanyu; Sun, Yuhan

2017-01-01

Cyanobacteria as biofertilizers are benefit to reduce the use of chemical fertilizers and reestablish the ecological system in soil. In general, several strains of cyanobacteria were involved in the biofertilizers. The co-cultivation of cyanobacteria were characterized on growth profile, production of polysaccharides and extracellular proteins, nitrogenase activity, and photosynthetic activity for three selected N 2 -fixing cyanobacteria, Anabaena cylindrica (B1611 and F243) and Nostoc sp. (F280). After eight-day culture, the highest dry weights were obtained in F280 pure culture and co-cultivation of B1611 and F280. Higher production of extracellular proteins and cell-bonding polysaccharides (CPS) were observed in co-cultivations compared with pure culture. The highest released polysaccharides (RPS) contents were obtained in pure culture of F280 and co-cultivation of F280 and F243. Galactose and glucose were major components of CPS and RPS in all samples. Trehalose was a specific component of RPS in F280 pure culture. Based on the monosaccharide contents of CPS and RPS, F280 was the dominant species in the related treatments of co-cultivation. The nitrogenase activities in all treatments exhibited a sharp rise at the late stage while a significant decrease existed when three cyanobacteria strains were mixed. Photosynthetic activities for all treatments were determined with rapid light curve, and the related parameters were estimated.

Role of Two Cell Wall Amidases in Septal Junction and Nanopore Formation in the Multicellular Cyanobacterium Anabaena sp. PCC 7120

PubMed Central

Bornikoel, Jan; Carrión, Alejandro; Fan, Qing; Flores, Enrique; Forchhammer, Karl; Mariscal, Vicente; Mullineaux, Conrad W.; Perez, Rebeca; Silber, Nadine; Wolk, C. Peter; Maldener, Iris

2017-01-01

Filamentous cyanobacteria have developed a strategy to perform incompatible processes in one filament by differentiating specialized cell types, N2-fixing heterocysts and CO2-fixing, photosynthetic, vegetative cells. These bacteria can be considered true multicellular organisms with cells exchanging metabolites and signaling molecules via septal junctions, involving the SepJ and FraCD proteins. Previously, it was shown that the cell wall lytic N-acetylmuramyl-L-alanine amidase, AmiC2, is essential for cell–cell communication in Nostoc punctiforme. This enzyme perforates the septal peptidoglycan creating an array of nanopores, which may be the framework for septal junction complexes. In Anabaena sp. PCC 7120, two homologs of AmiC2, encoded by amiC1 and amiC2, were identified and investigated in two different studies. Here, we compare the function of both AmiC proteins by characterizing different Anabaena amiC mutants, which was not possible in N. punctiforme, because there the amiC1 gene could not be inactivated. This study shows the different impact of each protein on nanopore array formation, the process of cell–cell communication, septal protein localization, and heterocyst differentiation. Inactivation of either amidase resulted in significant reduction in nanopore count and in the rate of fluorescent tracer exchange between neighboring cells measured by FRAP analysis. In an amiC1 amiC2 double mutant, filament morphology was affected and heterocyst differentiation was abolished. Furthermore, the inactivation of amiC1 influenced SepJ localization and prevented the filament-fragmentation phenotype that is characteristic of sepJ or fraC fraD mutants. Our findings suggest that both amidases are to some extent redundant in their function, and describe a functional relationship of AmiC1 and septal proteins SepJ and FraCD. PMID:28929086

Role of Two Cell Wall Amidases in Septal Junction and Nanopore Formation in the Multicellular Cyanobacterium Anabaena sp. PCC 7120.

PubMed

Bornikoel, Jan; Carrión, Alejandro; Fan, Qing; Flores, Enrique; Forchhammer, Karl; Mariscal, Vicente; Mullineaux, Conrad W; Perez, Rebeca; Silber, Nadine; Wolk, C Peter; Maldener, Iris

2017-01-01

Filamentous cyanobacteria have developed a strategy to perform incompatible processes in one filament by differentiating specialized cell types, N 2 -fixing heterocysts and CO 2 -fixing, photosynthetic, vegetative cells. These bacteria can be considered true multicellular organisms with cells exchanging metabolites and signaling molecules via septal junctions, involving the SepJ and FraCD proteins. Previously, it was shown that the cell wall lytic N -acetylmuramyl-L-alanine amidase, AmiC2, is essential for cell-cell communication in Nostoc punctiforme . This enzyme perforates the septal peptidoglycan creating an array of nanopores, which may be the framework for septal junction complexes. In Anabaena sp. PCC 7120, two homologs of AmiC2, encoded by amiC1 and amiC2 , were identified and investigated in two different studies. Here, we compare the function of both AmiC proteins by characterizing different Anabaena amiC mutants, which was not possible in N. punctiforme , because there the amiC1 gene could not be inactivated. This study shows the different impact of each protein on nanopore array formation, the process of cell-cell communication, septal protein localization, and heterocyst differentiation. Inactivation of either amidase resulted in significant reduction in nanopore count and in the rate of fluorescent tracer exchange between neighboring cells measured by FRAP analysis. In an amiC1 amiC2 double mutant, filament morphology was affected and heterocyst differentiation was abolished. Furthermore, the inactivation of amiC1 influenced SepJ localization and prevented the filament-fragmentation phenotype that is characteristic of sepJ or fraC fraD mutants. Our findings suggest that both amidases are to some extent redundant in their function, and describe a functional relationship of AmiC1 and septal proteins SepJ and FraCD.

Characterisation of the paralytic shellfish toxin biosynthesis gene clusters in Anabaena circinalis AWQC131C and Aphanizomenon sp. NH-5.

PubMed

Mihali, Troco K; Kellmann, Ralf; Neilan, Brett A

2009-03-30

Saxitoxin and its analogues collectively known as the paralytic shellfish toxins (PSTs) are neurotoxic alkaloids and are the cause of the syndrome named paralytic shellfish poisoning. PSTs are produced by a unique biosynthetic pathway, which involves reactions that are rare in microbial metabolic pathways. Nevertheless, distantly related organisms such as dinoflagellates and cyanobacteria appear to produce these toxins using the same pathway. Hypothesised explanations for such an unusual phylogenetic distribution of this shared uncommon metabolic pathway, include a polyphyletic origin, an involvement of symbiotic bacteria, and horizontal gene transfer. We describe the identification, annotation and bioinformatic characterisation of the putative paralytic shellfish toxin biosynthesis clusters in an Australian isolate of Anabaena circinalis and an American isolate of Aphanizomenon sp., both members of the Nostocales. These putative PST gene clusters span approximately 28 kb and contain genes coding for the biosynthesis and export of the toxin. A putative insertion/excision site in the Australian Anabaena circinalis AWQC131C was identified, and the organization and evolution of the gene clusters are discussed. A biosynthetic pathway leading to the formation of saxitoxin and its analogues in these organisms is proposed. The PST biosynthesis gene cluster presents a mosaic structure, whereby genes have apparently transposed in segments of varying size, resulting in different gene arrangements in all three sxt clusters sequenced so far. The gene cluster organizational structure and sequence similarity seems to reflect the phylogeny of the producer organisms, indicating that the gene clusters have an ancient origin, or that their lateral transfer was also an ancient event. The knowledge we gain from the characterisation of the PST biosynthesis gene clusters, including the identity and sequence of the genes involved in the biosynthesis, may also afford the identification of these gene clusters in dinoflagellates, the cause of human mortalities and significant financial loss to the tourism and shellfish industries.

Characterisation of the paralytic shellfish toxin biosynthesis gene clusters in Anabaena circinalis AWQC131C and Aphanizomenon sp. NH-5

PubMed Central

Mihali, Troco K; Kellmann, Ralf; Neilan, Brett A

2009-01-01

Background Saxitoxin and its analogues collectively known as the paralytic shellfish toxins (PSTs) are neurotoxic alkaloids and are the cause of the syndrome named paralytic shellfish poisoning. PSTs are produced by a unique biosynthetic pathway, which involves reactions that are rare in microbial metabolic pathways. Nevertheless, distantly related organisms such as dinoflagellates and cyanobacteria appear to produce these toxins using the same pathway. Hypothesised explanations for such an unusual phylogenetic distribution of this shared uncommon metabolic pathway, include a polyphyletic origin, an involvement of symbiotic bacteria, and horizontal gene transfer. Results We describe the identification, annotation and bioinformatic characterisation of the putative paralytic shellfish toxin biosynthesis clusters in an Australian isolate of Anabaena circinalis and an American isolate of Aphanizomenon sp., both members of the Nostocales. These putative PST gene clusters span approximately 28 kb and contain genes coding for the biosynthesis and export of the toxin. A putative insertion/excision site in the Australian Anabaena circinalis AWQC131C was identified, and the organization and evolution of the gene clusters are discussed. A biosynthetic pathway leading to the formation of saxitoxin and its analogues in these organisms is proposed. Conclusion The PST biosynthesis gene cluster presents a mosaic structure, whereby genes have apparently transposed in segments of varying size, resulting in different gene arrangements in all three sxt clusters sequenced so far. The gene cluster organizational structure and sequence similarity seems to reflect the phylogeny of the producer organisms, indicating that the gene clusters have an ancient origin, or that their lateral transfer was also an ancient event. The knowledge we gain from the characterisation of the PST biosynthesis gene clusters, including the identity and sequence of the genes involved in the biosynthesis, may also afford the identification of these gene clusters in dinoflagellates, the cause of human mortalities and significant financial loss to the tourism and shellfish industries. PMID:19331657

Regulation of Development and Nitrogen Fixation in Anabaena

DOE Office of Scientific and Technical Information (OSTI.GOV)

James W. Golden

2008-10-17

The regulation of development and cellular differentiation is important for all multicellular organisms. The nitrogen-fixing filamentous cyanobacterium Anabaena (also Nostoc) sp. PCC 7120 (hereafter Anabaena) provides a model of multicellular microbial development and pattern formation. Anabaena reduces N2 to ammonia in specialized terminally differentiated cells called heterocysts. A one-dimensional developmental pattern of single heterocysts regularly spaced along filaments of photosynthetic vegetative cells is established to form a multicellular organism composed of these two interdependent cell types. This multicellular growth pattern, the distinct phylogeny of cyanobacteria, and the suspected antiquity of heterocyst development make this an important model system. Our long-termmore » goal is to understand the regulatory network required for heterocyst development and nitrogen fixation. This project is focused on two key aspects of heterocyst regulation: one, the mechanism by which HetR controls the initiation of differentiation, and two, the cis and trans acting factors required for expression of the nitrogen-fixation (nif) genes. HetR is thought to be a central regulator of heterocyst development but the partners and mechanisms involved in this regulation are unknown. Our recent results indicate that PatS and other signals that regulate heterocyst pattern cannot interact, directly or indirectly, with a R223W mutant of HetR. We plan to use biochemical and genetic approaches to identify proteins that interact with the HetR protein, which will help reveal the mechanisms underlying its regulation of development. Our second goal is to determine how the nif genes are expressed. It is important to understand the mechanisms controlling nif genes since they represent the culmination of the differentiation process and the essence of heterocyst function. The Anabaena genome lacks the genes required for expression of nif genes present in other organisms such as rpoN (sigma 54) and nifA. We will use nifH-gfp reporter fusions to define the upstream sequences that are required for nifH expression and for genetic experiments to identify the trans-acting factors required for nifH regulation.« less

Divisome-dependent subcellular localization of cell-cell joining protein SepJ in the filamentous cyanobacterium Anabaena.

PubMed

Ramos-León, Félix; Mariscal, Vicente; Frías, José E; Flores, Enrique; Herrero, Antonia

2015-05-01

Heterocyst-forming cyanobacteria are multicellular organisms that grow as filaments that can be hundreds of cells long. Septal junction complexes, of which SepJ is a possible component, appear to join the cells in the filament. SepJ is a cytoplasmic membrane protein that contains a long predicted periplasmic section and localizes not only to the cell poles in the intercellular septa but also to a position similar to a Z ring when cell division starts suggesting a relation with the divisome. Here, we created a mutant of Anabaena sp. strain PCC 7120 in which the essential divisome gene ftsZ is expressed from a synthetic NtcA-dependent promoter, whose activity depends on the nitrogen source. In the presence of ammonium, low levels of FtsZ were produced, and the subcellular localization of SepJ, which was investigated by immunofluorescence, was impaired. Possible interactions of SepJ with itself and with divisome proteins FtsZ, FtsQ and FtsW were investigated using the bacterial two-hybrid system. We found SepJ self-interaction and a specific interaction with FtsQ, confirmed by co-purification and involving parts of the SepJ and FtsQ periplasmic sections. Therefore, SepJ can form multimers, and in Anabaena, the divisome has a role beyond cell division, localizing a septal protein essential for multicellularity. © 2015 John Wiley & Sons Ltd.

Hydrogen production by Anabaena cylindrica: effects of varying ammonium and ferric ions, pH, and light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeffries, T.W.; Timourian, H.; Ward, R.L.

Anabaena cylindrica sparged with argon gas produced H/sub 2/ continuously for 30 days under limited light conditions (6.0 W/m/sup 2/) and for 18 days under elevated light conditions (32 W/m/sup 2/) in the absence of exogenous nitrogen. The efficiency of converting visible light energy (32 W/m/sup 2/) into chemical energy that is trapped as H/sub 2/ ranged between 0.35 and 0.85% (approximately 13 ..mu..l of H/sub 2/ per mg (dry wt) per h). Ammonium additions (0.2 mM NH/sup +//sub 4/) at various times destabilized the system and eventually suppressed H/sub 2/ production completely, as compared with the control. Cultures grownmore » with 5.0 mg of Fe/sup 3 +/ per liter produced H/sub 2/ at a rate about twice that of cultures with 0.5 mg of Fe/sup 3 +/ per liter. Cultures grown at pH 7.4 produced H/sub 2/ at the same initial rates as cultures that were grown at pH 9.4; however, the latter cultures continued to produce H/sub 2/ after CO/sub 2/ deprivation.« less

Screening of Norharmane from Seven Cyanobacteria by High-performance Liquid Chromatography.

PubMed

Karan, Tunay; Erenler, Ramazan

2017-10-01

Cyanobacteria, including pharmaceutically and medicinally valuable compounds attract the great attention lately. Norharmane (9H-pyrido (3,4-b) indole found in some cyanobacteria revealed a great number of biological effects. Seven cyanobacteria were isolated and identified from Yesilirmak River and Gaziosmanpasa University Campus to determine the norharmane content. Cyanobacteria collected from Tokat, Turkey were isolated and identified by morphologically. Norharmane (9H-pyrido [3,4-b] indole) quantities were presented for seven cyanobacteria, Chroococcus minutus (Kütz.) Nägeli, Geitlerinema carotinosum (Geitler) Anagnostidis, Nostoc linckia Bornet ex Bornet and Flahault, Anabaena oryzae F. E. Fritsch, Oscillatoria limnetica Lemmermann, Phormidium sp . Kützing ex Gomont, and Cylindrospermum sp . Kutzing ex E. Bornet and C. Flahault by high-performance liquid chromatography. The norharmane amount indicated for cyanobacterial culture media altered in a species-dependent kind in the range of 0.81-10.87 μg/g. C. minutus produced the most norharmane among the investigated cyanobacteria as 10.87 μg/g. Cyanobacteria could be an important source of norharmane as well as pharmaceutically valuable compounds. Seven cyanobacteria were isolated and identified from Yesilirmak RiverQuantitative analysis of norharmane was executed on isolated cyanobacteriaFour cyanobecteria species included the norharmane Chroococcus minutus contained the most norharmane (10.87 μg/g). Abbreviations used: HPLC: High performance liquid chromatograph.

Anabaena sp. strain PCC 7120 conR contains a LytR-CpsA-Psr domain, is developmentally regulated, and is essential for diazotrophic growth and heterocyst morphogenesis.

PubMed

Mella-Herrera, Rodrigo A; Neunuebel, M Ramona; Golden, James W

2011-03-01

The conR (all0187) gene of the filamentous cyanobacterium Anabaena (Nostoc) sp. strain PCC 7120 is predicted to be part of a family of proteins that contain the LytR-CpsA-Psr domain associated with septum formation and cell wall maintenance. The conR gene was originally misannotated as a transcription regulator. Northern RNA blot analysis showed that conR expression was upregulated 8 h after nitrogen step-down. Fluorescence microscopy of a P(conR)-gfp reporter strain revealed increased GFP fluorescence in proheterocysts and heterocysts beginning 9 h after nitrogen step-down. Insertional inactivation of conR caused a septum-formation defect of vegetative cells grown in nitrate-containing medium. In nitrate-free medium, mutant filaments formed abnormally long heterocysts and were defective for diazotrophic growth. Septum formation between heterocysts and adjacent vegetative cells was abnormal, often with one or both poles of the heterocysts appearing partially open. In a conR mutant, expression of nifH was delayed after nitrogen step-down and nitrogenase activity was approximately 70 % of wild-type activity, indicating that heterocysts of the conR mutant strain are partially functional. We hypothesize that the diazotrophic growth defect is caused by an inability of the heterocysts to transport fixed nitrogen to the neighbouring vegetative cells.

Life cycle energy and greenhouse gas profile of a process for the production of ammonium sulfate from nitrogen-fixing photosynthetic cyanobacteria.

PubMed

Razon, Luis F

2012-03-01

In this paper, an alternative means for nitrogen fixation that may consume less energy and release less greenhouse gases than the Haber-Bosch process is explored. A life-cycle assessment was conducted on a process to: culture the cyanobacterium, Anabaena sp. ATCC 33047, in open ponds; harvest the biomass and exopolysaccharides and convert these to biogas; strip and convert the ammonia from the biogas residue to ammonium sulfate; dry the ammonium sulfate solution to ammonium sulfate crystals and transport the finished product. The results suggest that substantial reductions in non-renewable energy use and greenhouse gas emissions may be realized. The study opens the possibility that Haber-Bosch ammonia may be replaced with ammonia from a biomass process which simultaneously generates renewable energy. The process is intrinsically safer than the Haber-Bosch process. However, there are trade-offs in terms of land use and possibly, water. Copyright © 2011 Elsevier Ltd. All rights reserved.

Environmental impacts of cooling system on Abou Qir Bay.

PubMed

Mohamed, Manal A; Abd-Elaty, Magda M; El-Shall, Wafaa I; Ramadan, Abou Bakr; Tawfik, Mohamed S

2005-01-01

This study was conducted to evaluate the impacts of cooling water on cooling system of Abou Qir Power Plant and on the receiving Abou Qir Bay. Abou Qir Power Plant is a conventional steam electric power plant located in Alexandria Governorate, Egypt. Water and biota samples were collected monthly from cooling water and Abou Qir Bay over a year. Heavy metals, radionuclide, anions and total hydrocarbons were analyzed in the samples using Instrumental Neutron Activation Analysis (INAA), Gamma-ray Spectrometry (GS), Ion Selective Electrodes (ISE) and Gas Chromatography (GC). The results revealed that the characteristics of inlet cooling water had a tendency to be corrosive to the cooling system. The outlet cooling water complied with Environmental Law 4/1994 in all measured parameters except phosphate, ammonia and total petroleum hydrocarbons. On the other hand, samples from all sites had the lowest annual total count of algae in winter and highest count during summer. There are -ve correlations between algae and heavy metals, hydrocarbons, and radioactivity. Algae correlated highly significantly (p<0.01) with Pb, Cu, Ni, total petroleum hydrocarbons, dissolved petroleum hydrocarbon and uranium. Anabaena Sp. (blue green algae) and Euglina Sp.(flagellate) had highly significant (p<0.01) -ve correlation with heavy metals and natural radioactivity. The accumulation percentage of heavy metals by algae ranged from 22% to 37%, and the highest percent was for uranium and the lowest was for chromium. It is recommended to optimize the addition of polyphosphate inhibitor at inlet cooling water to inhibit corrosion in the cooling system and to avoid increase of Anabaena Sp. in the outlet, and to avoid enhancing algae growth that has a great tendency to accumulate heavy metals, and good housekeeping to avoid oil spills containing hydrocarbons from the power plant to sea water.

A Cluster of Five Genes Essential for the Utilization of Dihydroxamate Xenosiderophores in Synechocystis sp. PCC 6803.

PubMed

Obando S, Tobias A; Babykin, Michael M; Zinchenko, Vladislav V

2018-05-21

The unicellular freshwater cyanobacterium Synechocystis sp. PCC 6803 is capable of using dihydroxamate xenosiderophores, either ferric schizokinen (FeSK) or a siderophore of the filamentous cyanobacterium Anabaena variabilis ATCC 29413 (SAV), as the sole source of iron in the TonB-dependent manner. The fecCDEB1-schT gene cluster encoding a siderophore transport system that is involved in the utilization of FeSK and SAV in Synechocystis sp. PCC 6803 was identified. The gene schT encodes TonB-dependent outer membrane transporter, whereas the remaining four genes encode the ABC-type transporter FecB1CDE formed by the periplasmic binding protein FecB1, the transmembrane permease proteins FecC and FecD, and the ATPase FecE. Inactivation of any of these genes resulted in the inability of cells to utilize FeSK and SAV. Our data strongly suggest that Synechocystis sp. PCC 6803 can readily internalize Fe-siderophores via the classic TonB-dependent transport system.

Environmental and Cultural Resources within the Trinity River Basin

DTIC Science & Technology

1971-01-01

Berimnopedia - Trinity River, Tarrant County (66) Hiorecyatia - Trinity River, Tarrant County (66) Oseillatoria - Trinity River, Tarrant County (66) Spirulina ...73, 74) have reported additional algae and fungi from North Texas waters. These species are listed below. Anabaena Anacystic Arthrospira Chroococcus

Monitoring of Water Quality and Microalgae Species Composition of Penaeus monodon Ponds in Pulau Pinang, Malaysia

PubMed Central

Shaari, Asma Liyana; Surif, Misni; Latiff, Faazaz Abd.; Omar, Wan Maznah Wan; Ahmad, Mohd Noor

2011-01-01

Many reports have revealed that the abundance of microalgae in shrimp ponds vary with changes in environmental factors such as light, temperature, pH, salinity and nutrient level throughout a shrimp culture period. In this study, shrimp cultivation period was divided into three stages (initial = week 0–5, mid = week 6–10 and final = week 11–15). Physical and chemical parameters throughout the cultivation period were studied and species composition of microalgae was monitored. Physical parameters were found to fluctuate widely with light intensity ranging between 182.23–1278 μmol photon m−2s−1, temperature between 29.56°C −31.59°C, dissolved oxygen (DO) between 4.56–8.21 mg/l, pH between 7.65–8.49 and salinity between 20‰–30‰. Ammonium (NH4+-N), nitrite (NO2−-N), nitrate (NO3−-N), and orthophosphate (PO43−-P) concentrations in the pond at all cultivation stages ranged from 0.017 to 0.38 mg/l, 0.24 to 2.12 mg/l, 0.06 to 0.98 mg/l and 0.16 to 1.93 mg/l respectively. Statistical test (ANOVA) showed that there were no significant difference (p<0.05) in nutrients concentrations among the cultivation stages. All nutrients concentrations however were still in the tolerable level and safe for shrimp culture. The chlorophyll a contents were found to range from 5.03±2.17 to 32.61±0.35 μg/l throughout the cultivation period. A total of 19 microalgae species were found in the shrimp pond, with diatoms contributing up to 72% of the species followed by Chlorophyta (11%) and Cyanophyta (11%). However, weekly species abundance varied through the study period. At the initial stage, when there were no shrimps in the pond, Anabaena spp. and Oscillatoria spp. (Cyanophyta) were the dominant species, followed by Chlorella sp. and Dunaliella sp. (Chlorophyta). When shrimps were introduced into the pond, Amphora sp., Navicula sp. Gyrosigma sp. and Nitzschia sp. (diatoms) started to exist. At the middle and towards the final stage of the shrimp culture period diatoms were the dominant species. The Chlorophyta (Chlorella sp.) domination took place only twice, which was at week 2 and 13. The absence of some of the coastal water microalgae species in the shrimp pond was most likely due to the fact that they could not tolerate the physicochemical factors of harsh environment. In this study, Cylindrotheca closterium was regarded as the most tolerant species among the microalgae due to its ability to exist for 6 weeks out of the 15 weeks of cultivation. PMID:24575209

Hydrogen production by nitrogen-starved cultures of Anabaena cylindrica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weissman, J.C.; Benemann, J.R.

Nitrogen-starved cultures of the alga Anabaena cylindrica 629 produced hydrogen and oxygen continuously for 7 to 19 days. Hydrogen production attained a maximum level after 1 to 2 days of starvation and was followed by a slow decline. The maximum rates were 30 ml of H/sub 2/ evolved per liter of culture per h or 32 ..mu..l of H/sub 2/ per mg of dry weight per h. In 5 to 7 days the rate of H/sub 2/ evolution by the more productive cultures fell to one-half its maximum value. The addition of 10/sup -4/ to 5 x 10/sup -4/ Mmore » ammonium increased the rate of oxygen evolution and the total hydrogen production of the cultures. H/sub 2/-O/sub 2/ ratios were 4:1 under conditions of complete nitrogen starvation and about 1.7:1 after the addition of ammonium. Thus, oxygen evolution was affected by the extent of the nitrogen starvation. Thermodynamic efficiencies of converting incident light energy to free energy of hydrogen via algal photosynthesis were 0.4 percent. Possible factors limiting hydrogen production were decline of reductant supply and filament breakage. Hydrogen production by filamentous, heterocystous blue-green algae could be used for development of a biophotolysis system.« less

Acid base properties of cyanobacterial surfaces I: Influences of growth phase and nitrogen metabolism on cell surface reactivity

NASA Astrophysics Data System (ADS)

Lalonde, S. V.; Smith, D. S.; Owttrim, G. W.; Konhauser, K. O.

2008-03-01

Significant efforts have been made to elucidate the chemical properties of bacterial surfaces for the purposes of refining surface complexation models that can account for their metal sorptive behavior under diverse conditions. However, the influence of culturing conditions on surface chemical parameters that are modeled from the potentiometric titration of bacterial surfaces has received little regard. While culture age and metabolic pathway have been considered as factors potentially influencing cell surface reactivity, statistical treatments have been incomplete and variability has remained unconfirmed. In this study, we employ potentiometric titrations to evaluate variations in bacterial surface ligand distributions using live cells of the sheathless cyanobacterium Anabaena sp. strain PCC 7120, grown under a variety of batch culture conditions. We evaluate the ability for a single set of modeled parameters, describing acid-base surface properties averaged over all culture conditions tested, to accurately account for the ligand distributions modeled for each individual culture condition. In addition to considering growth phase, we assess the role of the various assimilatory nitrogen metabolisms available to this organism as potential determinants of surface reactivity. We observe statistically significant variability in site distribution between the majority of conditions assessed. By employing post hoc Tukey-Kramer analysis for all possible pair-wise condition comparisons, we conclude that the average parameters are inadequate for the accurate chemical description of this cyanobacterial surface. It was determined that for this Gram-negative bacterium in batch culture, ligand distributions were influenced to a greater extent by nitrogen assimilation pathway than by growth phase.

Dinitrogen-fixing cyanobacteria in microbial mats of two shallow coral reef ecosystems.

PubMed

Charpy, Loic; Palinska, Katarzyna A; Casareto, Beatriz; Langlade, Marie José; Suzuki, Yoshimi; Abed, Raeid M M; Golubic, Stjepko

2010-01-01

Dinitrogen-fixing organisms in cyanobacterial mats were studied in two shallow coral reef ecosystems: La Reunion Island, southwestern Indian Ocean, Sesoko (Okinawa) Island, and northwestern Pacific Ocean. Rapidly expanding benthic miniblooms, frequently dominated by a single cyanobacterial taxon, were identified by microscopy and molecular tools. In addition, nitrogenase activity by these blooms was measured in situ. Dinitrogen fixation and its contribution to mat primary production were calculated using (15)N(2) and (13)C methods. Dinitrogen-fixing cyanobacteria from mats in La Reunion and Sesoko showed few differences in taxonomic composition. Anabaena sp. among heterocystous and Hydrocoleum majus and Symploca hydnoides among nonheterocystous cyanobacteria occurred in microbial mats of both sites. Oscillatoria bonnemaisonii and Leptolyngbya spp. occurred only in La Reunion, whereas Hydrocoleum coccineum dominated in Sesoko. Other mats dominated by Hydrocoleum lyngbyaceum, Phormidium laysanense, and Trichocoleus tenerrimus occurred at lower frequencies. The 24-h nitrogenase activity, as measured by acetylene reduction, varied between 11 and 324 nmoles C(2)H(2) reduced microg(-1) Chl a. The highest values were achieved by heterocystous Anabaena sp. performed mostly during the day. Highest values for nonheterocystous cyanobacteria were achieved by H. coccineum mostly during the night. Daily nitrogen fixation varied from nine (Leptolyngbya) to 238 nmoles N(2) microg(-1) Chl day(-1) (H. coccineum). Primary production rates ranged from 1,321 (S. hydnoides) to 9,933 nmoles C microg(-1) Chl day(-1) (H. coccineum). Dinitrogen fixation satisfied between 5% and 21% of the nitrogen required for primary production.

Effect of nitrogen starvation on the level of adenosine 3',5'-monophosphate in Anabaena variabilis.

PubMed

Hood, E E; Armour, S; Ownby, J D; Handa, A K; Bressan, R A

1979-12-03

Low levels of adenosine 3',5'-monophosphate (cyclic AMP) were detected in the cyanobacterium Anabaena variabilis using a protein binding assay and two radioisotopic labelling methods. The basal concentration of intracellular cyclic AMP ranged from 0.27 pmol/mg protein in A. variabilis Kutz grown under heterotrophic conditions to 1.0--2.7 pmol/mg protein in A. variabilis strain 377 grown autotrophically. Extracellular cyclic AMP was found to comprise as much as 90% of the total cyclic AMP in rapidly growing cultures. When A. variabilis strain 377 was starved of nitrogen, a 3--4-fold increase in intracellular cyclic AMP was observed during the 24 h period coincident with early heterocyst development.

Carotenoid Biosynthesis in Calothrix sp. 336/3: Composition of Carotenoids on Full Medium, During Diazotrophic Growth and After Long-Term H2 Photoproduction.

PubMed

Kosourov, Sergey; Murukesan, Gayathri; Jokela, Jouni; Allahverdiyeva, Yagut

2016-11-01

The carotenoid composition of the filamentous heterocystous N 2 -fixing cyanobacterium Calothrix sp. 336/3 was investigated under three conditions: in full medium (non-diazotrophic growth); in the absence of combined nitrogen (diazotrophic growth); and after long-term H 2 photoproduction (diazotrophic medium and absence of nitrogen in the atmosphere). Anabaena sp. PCC 7120 and its ΔhupL mutant with disrupted uptake hydrogenase were used as reference strains. Analysis of identified carotenoids and enzymes involved in carotenogenesis showed the presence of three distinct biosynthetic pathways in Calothrix sp. 336/3. The first one is directed towards biosynthesis of myxoxanthophylls, such as myxol 2'-methylpentoside and 2-hydroxymyxol 2'-methylpentoside. The second pathway results in production of hydroxylated carotenoids, such as zeaxanthin, caloxanthin and nostoxanthin, and the last pathway is responsible for biosynthesis of echinenone and hydroxylated forms of ketocarotenoids, such as 3'-hydroxyechinenone and adonixanthin. We found that carotenogenesis in filamentous heterocystous cyanobacteria varies depending on the nitrogen status of the cultures, with significant accumulation of echinenone during diazotrophic growth at the expense of β-carotene. Under the severe N deficiency and high CO 2 supply, which leads to efficient H 2 photoproduction, cyanobacteria degrade echinenone and β-carotene, and accumulate glycosylated and hydroxylated carotenoids, such as myxol (or ketomyxol) 2'-methylpentosides, 3'-hydroxyechinenone and zeaxanthin. We suggest that the stability of the photosynthetic apparatus in Calothrix sp. 336/3 cells under N deficiency and high carbon conditions, which also appeared as the partial recovery of the pigment composition by the end of the long-term (∼1 month) H 2 photoproduction process, might be mediated by a high content of hydroxycarotenoids. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Screening of Norharmane from Seven Cyanobacteria by High-performance Liquid Chromatography

PubMed Central

Karan, Tunay; Erenler, Ramazan

2017-01-01

Background: Cyanobacteria, including pharmaceutically and medicinally valuable compounds attract the great attention lately. Norharmane (9H-pyrido (3,4-b) indole found in some cyanobacteria revealed a great number of biological effects. Objective: Seven cyanobacteria were isolated and identified from Yesilirmak River and Gaziosmanpasa University Campus to determine the norharmane content. Materials and Methods: Cyanobacteria collected from Tokat, Turkey were isolated and identified by morphologically. Norharmane (9H-pyrido [3,4-b] indole) quantities were presented for seven cyanobacteria, Chroococcus minutus (Kütz.) Nägeli, Geitlerinema carotinosum (Geitler) Anagnostidis, Nostoc linckia Bornet ex Bornet and Flahault, Anabaena oryzae F. E. Fritsch, Oscillatoria limnetica Lemmermann, Phormidium sp. Kützing ex Gomont, and Cylindrospermum sp. Kutzing ex E. Bornet and C. Flahault by high-performance liquid chromatography. Results: The norharmane amount indicated for cyanobacterial culture media altered in a species-dependent kind in the range of 0.81–10.87 μg/g. C. minutus produced the most norharmane among the investigated cyanobacteria as 10.87 μg/g. Conclusion: Cyanobacteria could be an important source of norharmane as well as pharmaceutically valuable compounds. SUMMARY Seven cyanobacteria were isolated and identified from Yesilirmak RiverQuantitative analysis of norharmane was executed on isolated cyanobacteriaFour cyanobecteria species included the norharmaneChroococcus minutus contained the most norharmane (10.87 μg/g). Abbreviations used: HPLC: High performance liquid chromatograph. PMID:29142439

Biodegradation of polychlorinated biphenyls (PCBs) by the novel identified cyanobacterium Anabaena PD-1

PubMed Central

Zhang, Hangjun; Jiang, Xiaojun; Lu, Liping; Xiao, Wenfeng

2015-01-01

Polychlorinated biphenyls (PCBs), a class of hazardous pollutants, are difficult to dissipate in the natural environment. In this study, a cyanobacterial strain Anabaena PD-1 showed good resistance against PCB congeners. Compared to a control group, chlorophyll a content decreased 3.7% and 11.7% when Anabaena PD-1 was exposed to 2 and 5 mg/L PCBs for 7 d. This cyanobacterial strain was capable of decomposing PCB congeners which was conclusively proved by determination of chloride ion concentrations in chlorine-free medium. After 7 d, the chloride ion concentrations in PCB-treated groups (1, 2, 5 mg/L) were 3.55, 3.05, and 2.25 mg/L, respectively. The genetic information of strain PD-1 was obtained through 16S rRNA sequencing analysis. The GenBank accession number of 16S rRNA of Anabaena PD-1 was KF201693.1. Phylogenetic tree analysis clearly indicated that Anabaena PD-1 belonged to the genus Anabaena. The degradation half-life of Aroclor 1254 by Anabaena PD-1 was 11.36 d; the total degradation rate for Aroclor 1254 was 84.4% after 25 d. Less chlorinated PCB congeners were more likely to be degraded by Anabaena PD-1 in comparison with highly chlorinated congeners. Meta- and para-chlorines in trichlorodiphenyls and tetrachlorobiphenyls were more susceptible to dechlorination than ortho-chlorines during the PCB-degradation process by Anabaena PD-1. Furthermore, Anabaena PD-1 can decompose dioxin-like PCBs. The percent biodegradation of 12 dioxin-like PCBs by strain PD-1 ranged from 37.4% to 68.4% after 25 days. Results above demonstrate that Anabaena PD-1 is a PCB-degrader with great potential for the in situ bioremediation of PCB-contaminated paddy soils. PMID:26177203

Algicidal activity of a dibenzofuran-degrader Rhodococcus sp.

PubMed

Wang, Meng-Hui; Peng, Peng; Liu, Yu-Mei; Jia, Rui-Bao; Li, Li

2013-02-01

Rhodococcus sp. strain p52, a previously isolated dibenzofuran degrader, could effectively inhibit the growth of cyanobacteria, including species of Microcystis, Anabaena, and Nodularia. When strain p52 was inoculated at the concentration of 7.7×10(7) CFU/ml, 93.5% of exponentially growing Microcystis aeruginosa (7.3×10(6) cells/ml initially) was inhibited after 4 day. The threshold concentration for its algicidal activity against M. aeruginosa was 7.7×10(6) CFU/ml. Strain p52 exerted algicidal effect by synthesizing extracellular substances, which were identified as trans-3-indoleacrylic acid, DL-pipecolic acid, and L-pyroglutamic acid. The effective concentrations of trans-3-indoleacrylic acid and DL-pipecolic acid against M. aeruginosa were tested to be 0.5 mg/l and 5 mg/l, respectively.

Highly effective, regiospecific reduction of chalcone by cyanobacteria leads to the formation of dihydrochalcone: two steps towards natural sweetness.

PubMed

Żyszka, Beata; Anioł, Mirosław; Lipok, Jacek

2017-08-04

Chalcones are the biogenetic precursors of all known flavonoids, which play an essential role in various metabolic processes in photosynthesizing organisms. The use of whole cyanobacteria cells in a two-step, light-catalysed regioselective bio-reduction of chalcone, leading to the formation of the corresponding dihydrochalcone, is reported. The prokaryotic microalgae cyanobacteria are known to produce phenolic compounds, including flavonoids, as natural components of cells. It seems logical that organisms producing such compounds possess a suitable "enzymatic apparatus" to carry out their biotransformation. Therefore, determination of the ability of whole cells of selected cyanobacteria to carry out biocatalytic transformations of chalcone, the biogenetic precursor of all known flavonoids, was the aim of our study. Chalcone was found to be converted to dihydrochalcone by all examined cyanobacterial strains; however, the effectiveness of this process depends on the strain with biotransformation yields ranging from 3% to >99%. The most effective biocatalysts are Anabaena laxa, Aphanizomenon klebahnii, Nodularia moravica, Synechocystis aquatilis (>99% yield) and Merismopedia glauca (92% yield). The strains Anabaena sp. and Chroococcus minutus transformed chalcone in more than one way, forming a few products; however, dihydrochalcone was the dominant product. The course of biotransformation shed light on the pathway of chalcone conversion, indicating that the process proceeds through the intermediate cis-chalcone. The scaled-up process, conducted on a preparative scale and by using a mini-pilot photobioreactor, fully confirmed the high effectiveness of this bioconversion. Moreover, in the case of the mini-pilot photobioreactor batch cultures, the optimization of culturing conditions allowed the shortening of the process conducted by A. klebahnii by 50% (from 8 to 4 days), maintaining its >99% yield. This is the first report related to the use of whole cells of halophilic and freshwater cyanobacteria strains in a two-step, light-catalysed regioselective bio-reduction of chalcone, leading to the formation of the corresponding dihydrochalcone. The total bioconversion of chalcone in analytical, preparative, and mini-pilot scales of this process creates the possibility of its use in the food industry for the production of natural sweeteners.

Induction of the Nitrate Assimilation nirA Operon and Protein-Protein Interactions in the Maturation of Nitrate and Nitrite Reductases in the Cyanobacterium Anabaena sp. Strain PCC 7120.

PubMed

Frías, José E; Flores, Enrique

2015-07-01

Nitrate is widely used as a nitrogen source by cyanobacteria, in which the nitrate assimilation structural genes frequently constitute the so-called nirA operon. This operon contains the genes encoding nitrite reductase (nirA), a nitrate/nitrite transporter (frequently an ABC-type transporter; nrtABCD), and nitrate reductase (narB). In the model filamentous cyanobacterium Anabaena sp. strain PCC 7120, which can fix N2 in specialized cells termed heterocysts, the nirA operon is expressed at high levels only in media containing nitrate or nitrite and lacking ammonium, a preferred nitrogen source. Here we examined the genes downstream of the nirA operon in Anabaena and found that a small open reading frame of unknown function, alr0613, can be cotranscribed with the operon. The next gene in the genome, alr0614 (narM), showed an expression pattern similar to that of the nirA operon, implying correlated expression of narM and the operon. A mutant of narM with an insertion mutation failed to produce nitrate reductase activity, consistent with the idea that NarM is required for the maturation of NarB. Both narM and narB mutants were impaired in the nitrate-dependent induction of the nirA operon, suggesting that nitrite is an inducer of the operon in Anabaena. It has previously been shown that the nitrite reductase protein NirA requires NirB, a protein likely involved in protein-protein interactions, to attain maximum activity. Bacterial two-hybrid analysis confirmed possible NirA-NirB and NarB-NarM interactions, suggesting that the development of both nitrite reductase and nitrate reductase activities in cyanobacteria involves physical interaction of the corresponding enzymes with their cognate partners, NirB and NarM, respectively. Nitrate is an important source of nitrogen for many microorganisms that is utilized through the nitrate assimilation system, which includes nitrate/nitrite membrane transporters and the nitrate and nitrite reductases. Many cyanobacteria assimilate nitrate, but regulation of the nitrate assimilation system varies in different cyanobacterial groups. In the N2-fixing, heterocyst-forming cyanobacteria, the nirA operon, which includes the structural genes for the nitrate assimilation system, is expressed in the presence of nitrate or nitrite if ammonium is not available to the cells. Here we studied the genes required for production of an active nitrate reductase, providing information on the nitrate-dependent induction of the operon, and found evidence for possible protein-protein interactions in the maturation of nitrate reductase and nitrite reductase. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

The hetC Gene Is a Direct Target of the NtcA Transcriptional Regulator in Cyanobacterial Heterocyst Development

PubMed Central

Muro-Pastor, Alicia M.; Valladares, Ana; Flores, Enrique; Herrero, Antonia

1999-01-01

The heterocyst is the site of nitrogen fixation in aerobically grown cultures of some filamentous cyanobacteria. Heterocyst development in Anabaena sp. strain PCC 7120 is dependent on the global nitrogen regulator NtcA and requires, among others, the products of the hetR and hetC genes. Expression of hetC, tested by RNA- DNA hybridization, was impaired in an ntcA mutant. A nitrogen-regulated, NtcA-dependent putative transcription start point was localized at nucleotide −571 with respect to the hetC translational start. Sequences upstream from this transcription start point exhibit the structure of the canonical cyanobacterial promoter activated by NtcA, and purified NtcA protein specifically bound to a DNA fragment containing this promoter. Activation of expression of hetC during heterocyst development appears thus to be directly operated by NtcA. NtcA-mediated activation of hetR expression was not impaired in a hetC mutant, indicating that HetC is not an NtcA-dependent element required for hetR induction. PMID:10542167

Outdoor biophotolytic system using the cyanobacterium anabaena cylindrica B629

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, G.D.; Lambert, G.R.

The cyanobacterium Anabaena cylindrica B629 was suspended in small glass beads and incubated in a gas-tight glass vessel outdoors under a gas atmosphere comprising carbon monoxide (0.2%), acetylene (5%), oxygen (6.5%), and nitrogen. The solution phase initially contained sodium bicarbonate (10mM) at pH 7. Under these conditions the organism continuously produced hydrogen gas for over three weeks. The temperature of the culture was maintained below 30 /degree/C and the minimum night temperatures were recorded. The vessel was covered by a shadecloth, which reduced the natural illumination by approximately 70%. The system is an alternative to those requiring the strict absencemore » of oxygen and little nitrogen, and requires virtually no attention during the incubation period. 18 refs.« less

Sodium: a factor in growth of blue-green algae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, Amelia Kay

The response of heterocystous blue-green algae to varying concentrations of sodium was examined in axenic culture as well as in situ studies. Laboratory cultures of Anabaena cylindrica were treated with four concentrations of sodium and three concentrations of nitrate to determine the response in terms of rates of acetylene reduction, 14C assimilation, excretion of organic carbon, concentration of chlorophyll a, particulate organic carbon, particulate organic nitrogen, and heterocyst and filament numbers.

Evaluation of light energy to H 2 energy conversion efficiency in thin films of cyanobacteria and green alga under photoautotrophic conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kosourov, Sergey; Murukesan, Gayathri; Seibert, Michael

Cyanobacteria and green algae harness solar energy to split water and to fix CO 2. Under specific conditions, they are capable of photoproduction of molecular hydrogen (H 2). This study compares the light-energy-to-hydrogen-energy conversion efficiency (LHCE) in two heterocystous, N 2-fixing cyanobacteria (wild-type Calothrix sp. strain 336/3 and the ΔhupL mutant of Anabaena sp. strain PCC 7120) and in the sulfur-deprived green alga, Chlamydomonas reinhardtii strain CC-124, after entrapment of the cells in thin Ca 2+-alginate films. The experiments, performed under photoautotrophic conditions, showed higher LHCEs in the cyanobacteria as compared to the green alga. The highest efficiency of ca.more » 2.5% was obtained in films of the entrapped ΔhupL strain under low light condition (2.9 W m -2). Calothrix sp. 336/3 films produced H 2 with a maximum efficiency of 0.6% under 2.9 W m -2, while C. reinhardtii films produced H 2 most efficiently under moderate light (0.14% at 12.1 W m -2). Exposure of the films to light above 16 W m -2 led to noticeable oxidative stress in all three strains, which increased with light intensity. The presence of oxidative stress was confirmed by increased (i) degradation of chlorophylls and some structural carotenoids (such as β-carotene), (ii) production of hydroxylated carotenoids (such as zeaxanthin), and (iii) carbonylation of proteins. We conclude that the H 2 photoproduction efficiency in immobilized algae and cyanobacteria can be further improved by entrapping cultures in immobilization matrices with increased permeability for gases, especially oxygen, while matrices with low porosity produced increased amounts of xanthophylls and other antioxidant compounds.« less

Evaluation of light energy to H 2 energy conversion efficiency in thin films of cyanobacteria and green alga under photoautotrophic conditions

DOE PAGES

Kosourov, Sergey; Murukesan, Gayathri; Seibert, Michael; ...

2017-10-14

Cyanobacteria and green algae harness solar energy to split water and to fix CO 2. Under specific conditions, they are capable of photoproduction of molecular hydrogen (H 2). This study compares the light-energy-to-hydrogen-energy conversion efficiency (LHCE) in two heterocystous, N 2-fixing cyanobacteria (wild-type Calothrix sp. strain 336/3 and the ΔhupL mutant of Anabaena sp. strain PCC 7120) and in the sulfur-deprived green alga, Chlamydomonas reinhardtii strain CC-124, after entrapment of the cells in thin Ca 2+-alginate films. The experiments, performed under photoautotrophic conditions, showed higher LHCEs in the cyanobacteria as compared to the green alga. The highest efficiency of ca.more » 2.5% was obtained in films of the entrapped ΔhupL strain under low light condition (2.9 W m -2). Calothrix sp. 336/3 films produced H 2 with a maximum efficiency of 0.6% under 2.9 W m -2, while C. reinhardtii films produced H 2 most efficiently under moderate light (0.14% at 12.1 W m -2). Exposure of the films to light above 16 W m -2 led to noticeable oxidative stress in all three strains, which increased with light intensity. The presence of oxidative stress was confirmed by increased (i) degradation of chlorophylls and some structural carotenoids (such as β-carotene), (ii) production of hydroxylated carotenoids (such as zeaxanthin), and (iii) carbonylation of proteins. We conclude that the H 2 photoproduction efficiency in immobilized algae and cyanobacteria can be further improved by entrapping cultures in immobilization matrices with increased permeability for gases, especially oxygen, while matrices with low porosity produced increased amounts of xanthophylls and other antioxidant compounds.« less

Mutation of the murC and murB Genes Impairs Heterocyst Differentiation in Anabaena sp. Strain PCC 7120

PubMed Central

Videau, Patrick; Rivers, Orion S.; Ushijima, Blake; Oshiro, Reid T.; Kim, Min Joo; Philmus, Benjamin

2016-01-01

ABSTRACT To stabilize cellular integrity in the face of environmental perturbations, most bacteria, including cyanobacteria, synthesize and maintain a strong, flexible, three-dimensional peptidoglycan lattice. Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium capable of differentiating morphologically distinct nitrogen-fixing heterocyst cells in a periodic pattern. While heterocyst development has been shown to require proper peptidoglycan remodeling, the role of peptidoglycan synthesis has remained unclear. Here we report the identification of two peptidoglycan synthesis genes, murC (alr5065) and murB (alr5066), as required for heterocyst development. The murC and murB genes are predicted to encode a UDP-N-acetylmuramate:l-alanine ligase and a UDP-N-acetylenolpyruvoylglucosamine reductase, respectively, and we confirm enzymatic function through complementation of Escherichia coli strains deficient for these enzymes. Cells depleted of either murC or murB expression failed to differentiate heterocysts under normally inducing conditions and displayed decreased filament integrity. To identify the stage(s) of development affected by murC or murB depletion, the spatial distribution of expression of the patterning marker gene, patS, was examined. Whereas murB depletion did not affect the pattern of patS expression, murC depletion led to aberrant expression of patS in all cells of the filament. Finally, expression of gfp controlled by the region of DNA immediately upstream of murC was enriched in differentiating cells and was repressed by the transcription factor NtcA. Collectively, the data in this work provide evidence for a direct link between peptidoglycan synthesis and the maintenance of a biological pattern in a multicellular organism. IMPORTANCE Multicellular organisms that differentiate specialized cells must regulate morphological changes such that both cellular integrity and the dissemination of developmental signals are preserved. Here we show that the multicellular bacterium Anabaena, which differentiates a periodic pattern of specialized heterocyst cells, requires peptidoglycan synthesis by the murine ligase genes murC (alr5065) and murB (alr5066) for maintenance of patterned gene expression, filament integrity, and overall development. This work highlights the significant influence that intracellular structure and intercellular connections can have on the execution of a developmental program. PMID:26811320

Mutation of the murC and murB Genes Impairs Heterocyst Differentiation in Anabaena sp. Strain PCC 7120.

PubMed

Videau, Patrick; Rivers, Orion S; Ushijima, Blake; Oshiro, Reid T; Kim, Min Joo; Philmus, Benjamin; Cozy, Loralyn M

2016-04-01

To stabilize cellular integrity in the face of environmental perturbations, most bacteria, including cyanobacteria, synthesize and maintain a strong, flexible, three-dimensional peptidoglycan lattice. Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium capable of differentiating morphologically distinct nitrogen-fixing heterocyst cells in a periodic pattern. While heterocyst development has been shown to require proper peptidoglycan remodeling, the role of peptidoglycan synthesis has remained unclear. Here we report the identification of two peptidoglycan synthesis genes, murC (alr5065) and murB (alr5066), as required for heterocyst development. The murC and murB genes are predicted to encode a UDP-N-acetylmuramate:L-alanine ligase and a UDP-N-acetylenolpyruvoylglucosamine reductase, respectively, and we confirm enzymatic function through complementation of Escherichia coli strains deficient for these enzymes. Cells depleted of either murC or murB expression failed to differentiate heterocysts under normally inducing conditions and displayed decreased filament integrity. To identify the stage(s) of development affected by murC or murB depletion, the spatial distribution of expression of the patterning marker gene, patS, was examined. Whereas murB depletion did not affect the pattern of patS expression, murC depletion led to aberrant expression of patS in all cells of the filament. Finally, expression of gfp controlled by the region of DNA immediately upstream of murC was enriched in differentiating cells and was repressed by the transcription factor NtcA. Collectively, the data in this work provide evidence for a direct link between peptidoglycan synthesis and the maintenance of a biological pattern in a multicellular organism. Multicellular organisms that differentiate specialized cells must regulate morphological changes such that both cellular integrity and the dissemination of developmental signals are preserved. Here we show that the multicellular bacterium Anabaena, which differentiates a periodic pattern of specialized heterocyst cells, requires peptidoglycan synthesis by the murine ligase genes murC (alr5065) and murB (alr5066) for maintenance of patterned gene expression, filament integrity, and overall development. This work highlights the significant influence that intracellular structure and intercellular connections can have on the execution of a developmental program. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Nezha, a novel active miniature inverted-repeat transposable element in cyanobacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou Fengfeng; Tran Thao; Xu Ying

2008-01-25

Miniature inverted-repeat transposable elements (MITEs) were first identified in plants and exerted extensive proliferations throughout eukaryotic and archaeal genomes. But very few MITEs have been characterized in bacteria. We identified a novel MITE, called Nezha, in cyanobacteria Anabaena variabilis ATCC 29413 and Nostoc sp. PCC 7120. Nezha, like most previously known MITEs in other organisms, is small in size, non-coding, carrying TIR and DR signals, and of potential to form a stable RNA secondary structure, and it tends to insert into A+T-rich regions. Recent transpositions of Nezha were observed in A. variabilis ATCC 29413 and Nostoc sp. PCC 7120, respectively.more » Nezha might have proliferated recently with aid from the transposase encoded by ISNpu3-like elements. A possible horizontal transfer event of Nezha from cyanobacteria to Polaromonas JS666 is also observed.« less

Nitric oxide ameliorates the damaging effects of oxidative stress induced by iron deficiency in cyanobacterium Anabaena 7120.

PubMed

Kaushik, Manish Singh; Srivastava, Meenakshi; Srivastava, Alka; Singh, Anumeha; Mishra, Arun Kumar

2016-11-01

In cyanobacterium Anabaena 7120, iron deficiency leads to oxidative stress with unavoidable consequences. Nitric oxide reduces pigment damage and supported the growth of Anabaena 7120 in iron-deficient conditions. Elevation in nitric oxide accumulation and reduced superoxide radical production justified the role of nitric oxide in alleviating oxidative stress in iron deficiency. Increased activities of antioxidative enzymes and higher levels of ROS scavengers (ascorbate, glutathione and thiol) in iron deficiency were also observed in the presence of nitric oxide. Nitric oxide also supported the membrane integrity of Anabaena cells and reduces protein and DNA damage caused by oxidative stress induced by iron deficiency. Results suggested that nitric oxide alleviates the damaging effects of oxidative stress induced by iron deficiency in cyanobacterium Anabaena 7120.

The heterocyst regulatory protein HetP and its homologs modulate heterocyst commitment in Anabaena sp. strain PCC 7120.

PubMed

Videau, Patrick; Rivers, Orion S; Hurd, Kathryn; Ushijima, Blake; Oshiro, Reid T; Ende, Rachel J; O'Hanlon, Samantha M; Cozy, Loralyn M

2016-10-24

The commitment of differentiating cells to a specialized fate is fundamental to the correct assembly of tissues within a multicellular organism. Because commitment is often irreversible, entry into and progression through this phase of development must be tightly regulated. Under nitrogen-limiting conditions, the multicellular cyanobacterium Anabaena sp. strain PCC 7120 terminally commits ∼10% of its cells to become specialized nitrogen-fixing heterocysts. Although commitment is known to occur 9-14 h after the induction of differentiation, the factors that regulate the initiation and duration of this phase have yet to be elucidated. Here, we report the identification of four genes that share a functional domain and modulate heterocyst commitment: hetP (alr2818), asl1930, alr2902, and alr3234 Epistatic relationships between all four genes relating to commitment were revealed by deleting them individually and in combination; asl1930 and alr3234 acted most upstream to delay commitment, alr2902 acted next in the pathway to inhibit development, and hetP acted most downstream to drive commitment forward. Possible protein-protein interactions between HetP, its homologs, and the heterocyst master regulator, HetR, were assessed, and interaction partners were defined. Finally, patterns of gene expression for each homolog, as determined by promoter fusions to gfp and reverse transcription-quantitative PCR, were distinct from that of hetP in both spatiotemporal organization and regulation. We posit that a dynamic succession of protein-protein interactions modulates the timing and efficiency of the commitment phase of development and note that this work highlights the utility of a multicellular cyanobacterium as a model for the study of developmental processes.

Azolla-Anabaena Relationship

PubMed Central

Ray, Thomas B.; Mayne, Berger C.; Toia, Robert E.; Peters, Gerald A.

1979-01-01

Photosynthesis in the Azolla-Anabaena association was characterized with respect to photorespiration, early products of photosynthesis, and action spectra. Photorespiration as evidenced by an O2 inhibition of photosynthesis and an O2-dependent CO2 compensation concentration was found to occur in the association, and endophyte-free fronds, but not in the endophytic Anabaena. Analysis of the early products of photosynthesis indicated that both the fern and cyanobacterium fix CO2 via the Calvin cycle. The isolated endophytic Anabaena did not release significant amounts of amino acids synthesized from recently fixed carbon. The action spectra for photosynthesis in the Azolla-Anabaena association indicated that the maximum quantum yield is between 650 and 670 nanometers, while in the endophyte the maximum is between 580 and 640 nanometers. Although the endophytic cyanobacterium is photosynthetically competent, any contribution it makes to photosynthesis in the intact association was not apparent in the action spectrum. PMID:16661055

Cloning, overexpression and interaction of recombinant Fur from the cyanobacterium Anabaena PCC 7119 with isiB and its own promoter.

PubMed

Bes, M T; Hernández, J A; Peleato, M L; Fillat, M F

2001-01-15

A gene coding for a Fur (ferric uptake regulation) protein from the cyanobacterium Anabaena PCC 7119 has been cloned and overexpressed in Escherichia coli. DNA sequence analysis confirmed the presence of a 151-amino-acid open reading frame that showed homology with the Fur proteins reported for the unicellular cyanobacteria Synechococcus 7942 and Synechocystis PCC 6803. Two putative Fur-binding sites were detected in the promoter regions of the fur gene from Anabaena. Partially purified recombinant Fur binds to the flavodoxin promoter as well as its own promoter. This suggests that the Fur gene is autoregulated in Anabaena.

Genetic studies on a nitrogen-fixing cyanobacterium. [Anabaena; Escherichi coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolk, C.P.; Cardemil, L.; Elhai, J.

1987-04-01

Mutants of Anabaena PCC7120 capable of aerobic growth with NO/sub 3//sup -/ but not N/sub 2/, and capable of microaerobic reduction of C/sub 2/H/sub 2/, were isolated by penicillin enrichment after UV irradiation. Heterocysts of two mutants lack the principal envelope glycolipid, those of EF116 have a non-cohesive envelope polysaccharide, and those of other strains have other defects. A Nm/sup r/ cosmid library of DNA from wild type Anabaena PCC7120 was established in Escherichia coli bearing the Ap helper plasmid pDS4101. A conjugative plasmid was introduced, and the bacteria replicated to lawns of individual mutant strains of Anabaena. After onemore » day of non-selective growth, selection was applied for Nm/sup r/ and nitrogen fixation. Overlapping cosmids complementing EF116 and one complementing another mutant have been mapped. The complementing genes are thought to act early in differentiation. Inclusion, in an E. coli donor of an appropriate methylase gene enhanced, by a factor of 10/sup 2/ to 10/sup 3/, transfer to Anabaena PCC7120 of a plasmid containing numerous sites for the Anabaena restriction endonuclease, AvaII.« less

Deciphering the factors associated with the colonization of rice plants by cyanobacteria.

PubMed

Bidyarani, Ngangom; Prasanna, Radha; Chawla, Gautam; Babu, Santosh; Singh, Rajendra

2015-04-01

Cyanobacteria-rice plant interactions were analyzed using a hydroponics experiment. The activity of plant defense and pathogenesis-related enzymes, scanning electron microscopy, growth, nitrogen fixation (measured as ARA), and DNA fingerprinting assays proved useful in illustrating the nature of associations of cyanobacteria with rice plants. Microscopic analyses revealed the presence of short filaments and coiled masses of filaments of cyanobacteria near the epidermis and cortex of roots and shoot tissues. Among the six cyanobacterial strains employed, Calothrix sp. (RPC1), Anabaena laxa (RPAN8), and Anabaena azollae (C16) were the best performing strains, in terms of colonization in roots and stem. These strains also enhanced nitrogen fixation and stimulated the activity of plant defense/cell wall-degrading enzymes. A significantly high correlation was also recorded between the elicited plant enzymes, growth, and ARA. DNA fingerprinting using highly iterated palindromic sequences (HIP-TG) further helped in proving the establishment of inoculated organisms in the roots/shoots of rice plants. This study illustrated that the colonization of cyanobacteria in the plant tissues is facilitated by increased elicitation of plant enzymes, leading to improved plant growth, nutrient mobilization, and enhanced plant fitness. Such strains can be promising candidates for developing "cyanobacteria colonized-nitrogen-fixing rice plants" in the future. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Membrane anchoring of aminoacyl-tRNA synthetases by convergent acquisition of a novel protein domain.

PubMed

Olmedo-Verd, Elvira; Santamaría-Gómez, Javier; Ochoa de Alda, Jesús A G; Ribas de Pouplana, Lluis; Luque, Ignacio

2011-11-25

Four distinct aminoacyl-tRNA synthetases (aaRSs) found in some cyanobacterial species contain a novel protein domain that bears two putative transmembrane helices. This CAAD domain is present in glutamyl-, isoleucyl-, leucyl-, and valyl-tRNA synthetases, the latter of which has probably recruited the domain more than once during evolution. Deleting the CAAD domain from the valyl-tRNA synthetase of Anabaena sp. PCC 7120 did not significantly modify the catalytic properties of this enzyme, suggesting that it does not participate in its canonical tRNA-charging function. Multiple lines of evidence suggest that the function of the CAAD domain is structural, mediating the membrane anchorage of the enzyme, although membrane localization of aaRSs has not previously been described in any living organism. Synthetases containing the CAAD domain were localized in the intracytoplasmic thylakoid membranes of cyanobacteria and were largely absent from the plasma membrane. The CAAD domain was necessary and apparently sufficient for protein targeting to membranes. Moreover, localization of aaRSs in thylakoids was important under nitrogen limiting conditions. In Anabaena, a multicellular filamentous cyanobacterium often used as a model for prokaryotic cell differentiation, valyl-tRNA synthetase underwent subcellular relocation at the cell poles during heterocyst differentiation, a process also dependent on the CAAD domain.

Quantification of Concentration of Microalgae Anabaena Cylindrica, Coal-bed Methane Water Isolates Nannochloropsis Gaditana and PW-95 in Aquatic Solutions through Hyperspectral Reflectance Measurement and Analytical Model Establishment

NASA Astrophysics Data System (ADS)

Zhou, Z.; Zhou, X.; Apple, M. E.; Spangler, L.

2017-12-01

Three species of microalgae, Anabaena cylindrica (UTEX # 1611), coal-bed methane water isolates Nannochloropsis gaditana and PW-95 were cultured for the measurements of their hyperspectral profiles in different concentrations. The hyperspectral data were measured by an Analytical Spectral Devices (ASD) spectroradiomter with the spectral resolution of 1 nanometer over the wavelength ranges from 350nm to 1050 nm for samples of microalgae of different concentration. Concentration of microalgae was measured using a Hemocytometer under microscope. The objective of this study is to establish the relation between spectral reflectance and micro-algal concentration so that microalgae concentration can be measured remotely by space- or airborne hyperspectral or multispectral sensors. Two types of analytical models, linear reflectance-concentration model and Lamber-Beer reflectance-concentration model, were established for each species. For linear modeling, the wavelength with the maximum correlation coefficient between the reflectance and concentrations of algae was located and then selected for each species of algae. The results of the linear models for each species are shown in Fig.1(a), in which Refl_1, Refl_2, and Refl_3 represent the reflectance of Anabaena, N. Gaditana, and PW-95 respectively. C1, C2, and C3 represent the Concentrations of Anabaena, N. Gaditana, and PW-95 respectively. The Lamber-Beer models were based on the Lambert-Beer Law, which states that the intensity of light propagating in a substance dissolved in a fully transmitting solvent is directly proportional to the concentration of the substance and the path length of the light through the solution. Thus, for the Lamber-Beer modeling, a wavelength with large absorption in red band was selected for each species. The results of Lambert-Beer models for each species are shown in Fig.1(b). Based on the Lamber-Beer models, the absorption coefficient for the three different species will be quantified.

Geographical Segregation of the Neurotoxin-Producing Cyanobacterium Anabaena circinalis

PubMed Central

Beltran, E. Carolina; Neilan, Brett A.

2000-01-01

Blooms of the cyanobacterium Anabaena circinalis are a major worldwide problem due to their production of a range of toxins, in particular the neurotoxins anatoxin-a and paralytic shellfish poisons (PSPs). Although there is a worldwide distribution of A. circinalis, there is a geographical segregation of neurotoxin production. American and European isolates of A. circinalis produce only anatoxin-a, while Australian isolates exclusively produce PSPs. The reason for this geographical segregation of neurotoxin production by A. circinalis is unknown. The phylogenetic structure of A. circinalis was determined by analyzing 16S rRNA gene sequences. A. circinalis was found to form a monophyletic group of international distribution. However, the PSP- and non-PSP-producing A. circinalis formed two distinct 16S rRNA gene clusters. A molecular probe was designed, allowing the identification of A. circinalis from cultured and uncultured environmental samples. In addition, probes targeting the predominantly PSP-producing or non-PSP-producing clusters were designed for the characterization of A. circinalis isolates as potential PSP producers. PMID:11010900

ORGANIZATION OF THE nif GENES OF THE NONHETEROCYSTOUS CYANOBACTERIUM TRICHODESMIUM SP. IMS101.

PubMed

Dominic, Benny; Zani, Sabino; Chen, Yi-Bu; Mellon, Mark T; Zehr, Jonathan P

2000-08-26

An approximately 16-kb fragment of the Trichodesmium sp. IMS101 (a nonheterocystous filamentous cyanobacterium) "conventional"nif gene cluster was cloned and sequenced. The gene organization of the Trichodesmium and Anabaena variabilis vegetative (nif 2) nitrogenase gene clusters spanning the region from nif B to nif W are similar except for the absence of two open reading frames (ORF3 and ORF1) in Trichodesmium. The Trichodesmium nif EN genes encode a fused Nif EN polypeptide that does not appear to be processed into individual Nif E and Nif N polypeptides. Fused nif EN genes were previously found in the A. variabilis nif 2 genes, but we have found that fused nif EN genes are widespread in the nonheterocystous cyanobacteria. Although the gene organization of the nonheterocystous filamentous Trichodesmium nif gene cluster is very similar to that of the A. variabilis vegetative nif 2 gene cluster, phylogenetic analysis of nif sequences do not support close relatedness of Trichodesmium and A. variabilis vegetative (nif 2) nitrogenase genes.

Survey of cyanobacterial toxins in Czech water reservoirs--the first observation of neurotoxic saxitoxins.

PubMed

Jančula, Daniel; Straková, Lucie; Sadílek, Jan; Maršálek, Blahoslav; Babica, Pavel

2014-01-01

The environmental occurrence and concentrations of cyanobacterial toxins (cyanotoxins) were investigated in the Czech Republic. Concentrations of microcystins (MCs), cylindrospermopsin (CYN) or saxitoxins (STXs) were determined immunochemically by ELISA assays in 30 water samples collected from the surface layers of 19 reservoirs during the summer season of 2010. MCs were detected in 18 reservoirs and 83 % of samples, with median and maximal concentration being 1.5 and 18.6 μg/L, respectively. The high frequency of MC occurrence coincided with prevalence of cyanobacterium Microcystis sp., which was detected in 87 % samples, followed by Dolichospermum (Anabaena) sp. observed in 33 % samples. CYN was detected by ELISA only in one sample at a concentration of 1.2 μg/L. STXs presence was indicated for the first time in Czech water reservoirs when the toxins were found at low concentrations (0.03-0.04 μg/L) in two samples (7 %) collected from two different reservoirs, where STXs co-occurred with MCs and eventually also with CYN. In both STX-positive samples, the phytoplankton community was dominated by Microcystis sp., but Dolichospermum sp. and/or Aphanizomenon sp. were also present as putative producers of STX and/or CYN. Cyanotoxins commonly occurred in Czech water reservoirs, and MCs frequently at concentrations possibly associated with human health risks. MCs were the most prevalent and abundant cyanotoxins, but also other cyanotoxins were detected, though sporadically. Further research and regulatory monitoring of cyanotoxins other than MCs is therefore required.

Intercellular diffusion of a fluorescent sucrose analog via the septal junctions in a filamentous cyanobacterium.

PubMed

Nürnberg, Dennis J; Mariscal, Vicente; Bornikoel, Jan; Nieves-Morión, Mercedes; Krauß, Norbert; Herrero, Antonia; Maldener, Iris; Flores, Enrique; Mullineaux, Conrad W

2015-03-17

Many filamentous cyanobacteria produce specialized nitrogen-fixing cells called heterocysts, which are located at semiregular intervals along the filament with about 10 to 20 photosynthetic vegetative cells in between. Nitrogen fixation in these complex multicellular bacteria depends on metabolite exchange between the two cell types, with the heterocysts supplying combined-nitrogen compounds but dependent on the vegetative cells for photosynthetically produced carbon compounds. Here, we used a fluorescent tracer to probe intercellular metabolite exchange in the filamentous heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. We show that esculin, a fluorescent sucrose analog, is incorporated by a sucrose import system into the cytoplasm of Anabaena cells. The cytoplasmic esculin is rapidly and reversibly exchanged across vegetative-vegetative and vegetative-heterocyst cell junctions. Our measurements reveal the kinetics of esculin exchange and also show that intercellular metabolic communication is lost in a significant fraction of older heterocysts. SepJ, FraC, and FraD are proteins located at the intercellular septa and are suggested to form structures analogous to gap junctions. We show that a ΔsepJ ΔfraC ΔfraD triple mutant shows an altered septum structure with thinner septa but a denser peptidoglycan layer. Intercellular diffusion of esculin and fluorescein derivatives is impaired in this mutant, which also shows a greatly reduced frequency of nanopores in the intercellular septal cross walls. These findings suggest that FraC, FraD, and SepJ are important for the formation of junctional structures that constitute the major pathway for feeding heterocysts with sucrose. Anabaena and its relatives are filamentous cyanobacteria that exhibit a sophisticated form of prokaryotic multicellularity, with the formation of differentiated cell types, including normal photosynthetic cells and specialized nitrogen-fixing cells called heterocysts. The question of how heterocysts communicate and exchange metabolites with other cells in the filament is key to understanding this form of bacterial multicellularity. Here we provide the first information on the intercellular exchange of a physiologically important molecule, sucrose. We show that a fluorescent sucrose analog can be imported into the Anabaena cytoplasm by a sucrose import system. Once in the cytoplasm, it is rapidly and reversibly exchanged among all of the cells in the filament by diffusion across the septal junctions. Photosynthetically produced sucrose likely follows the same route from cytoplasm to cytoplasm. We identify some of the septal proteins involved in sucrose exchange, and our results indicate that these proteins form structures functionally analogous to metazoan gap junctions. Copyright © 2015 Nürnberg et al.

Construction of shuttle vectors capable of conjugative transfer from Escherichia coli to nitrogen-fixing filamentous cyanobacteria.

PubMed Central

Wolk, C P; Vonshak, A; Kehoe, P; Elhai, J

1984-01-01

Wild-type cyanobacteria of the genus Anabaena are capable of oxygenic photosynthesis, differentiation of cells called heterocysts at semiregular intervals along the cyanobacterial filaments, and aerobic nitrogen fixation by the heterocysts. To foster analysis of the physiological processes characteristic of these cyanobacteria, we have constructed a family of shuttle vectors capable of replication and selection in Escherichia coli and, in unaltered form, in several strains of Anabaena. Highly efficient conjugative transfer of these vectors from E. coli to Anabaena is dependent upon the presence of broad host-range plasmid RP-4 and of helper plasmids. The shuttle vectors contain portions of plasmid pBR322 required for replication and mobilization, with sites for Anabaena restriction enzymes deleted; cyanobacterial replicon pDU1, which lacks such sites; and determinants for resistance to chloramphenicol, streptomycin, neomycin, and erythromycin. Images PMID:6324204

Environmental influence on cyanobacteria abundance and microcystin toxin production in a shallow temperate lake.

PubMed

Lee, Tammy A; Rollwagen-Bollens, Gretchen; Bollens, Stephen M; Faber-Hammond, Joshua J

2015-04-01

The increasing frequency of harmful cyanobacterial blooms in freshwater systems is a commonly recognized problem due to detrimental effects on water quality. Vancouver Lake, a shallow, tidally influenced lake in the flood plain of the Columbia River within the city of Vancouver, WA, USA, has experienced numerous summertime cyanobacterial blooms, dominated by Aphanizomenon sp. and Anabaena sp. Cyanobacteria abundance and toxin (microcystin) levels have been monitored in this popular urban lake for several years; however, no previous studies have identified which cyanobacteria species produce toxins, nor analyzed how changes in environmental variables contribute to the fluctuations in toxic cyanobacteria populations. We used a suite of molecular techniques to analyze water samples from Vancouver Lake over two summer bloom cycles (2009 and 2010). Both intracellular and extracellular microcystin concentrations were measured using an ELISA kit. Intracellular microcystin concentrations exceeded WHO guidelines for recreational waters several times throughout the sampling period. PCR results demonstrated that Microcystis sp. was the sole microcystin-producing cyanobacteria species present in Vancouver Lake, although Microcystis sp. was rarely detected in microscopical counts. qPCR results indicated that the majority of the Microcystis sp. population contained the toxin-producing gene (mcyE), although Microcystis sp. abundance rarely exceeded 1 percent of overall cyanobacteria abundance. Non-metric multidimensional scaling (NMDS) revealed that PO4-P was the main environmental variable influencing the abundance of toxic and non-toxic cyanobacteria, as well as intracellular microcystin concentrations. Our study underscores the importance of using molecular genetic techniques, in addition to traditional microscopy, to assess the importance of less conspicuous species in the dynamics of harmful algal blooms. Copyright © 2014 Elsevier Inc. All rights reserved.

A core of three amino acids at the carboxyl-terminal region of glutamine synthetase defines its regulation in cyanobacteria.

PubMed

Saelices, Lorena; Robles-Rengel, Rocío; Florencio, Francisco J; Muro-Pastor, M Isabel

2015-05-01

Glutamine synthetase (GS) type I is a key enzyme in nitrogen metabolism, and its activity is finely controlled by cellular carbon/nitrogen balance. In cyanobacteria, a reversible process that involves protein-protein interaction with two proteins, the inactivating factors IF7 and IF17, regulates GS. Previously, we showed that three arginine residues of IFs are critical for binding and inhibition of GS. In this work, taking advantage of the specificity of GS/IFs interaction in the model cyanobacteria Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120, we have constructed a different chimeric GSs from these two cyanobacteria. Analysis of these proteins, together with a site-directed mutagenesis approach, indicates that a core of three residues (E419, N456 and R459) is essential for the inactivation process. The three residues belong to the last 56 amino acids of the C-terminus of Synechocystis GS. A protein-protein docking modeling of Synechocystis GS in complex with IF7 supports the role of the identified core for GS/IF interaction. © 2015 John Wiley & Sons Ltd.

Hydrogenase activity in the thermophile mastigocladus laminosus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benemann, J.R.; Miyamoto, K.; Hallenbeck, P.C.

Hydrogenase activity in the thermophilic cyanobacterium, Mastigocladus laminosus was studied both in vivo and in vitro. In vivo hydrogen consumption required oxygen but not light, was about ten-fold higher than in mesophilic cyanobacteria, and was relatively insensitive to carbon monoxide. H/sub 2/-supported acetylene reduction in reductant-limited cultures was a light-dependent, but O/sub 2/-independent reaction. In vitro hydrogen evolution was unaffected by carbon monoxide, and this activity could be partially purified using a procedure developed for Anabaena cylindrica.

Effects of UV-B and heavy metals on nitrogen and phosphorus metabolism in three cyanobacteria.

PubMed

Yadav, Shivam; Prajapati, Rajesh; Atri, Neelam

2016-01-01

Cyanobacteria sp. (diazotrophic and planktonic) hold a major position in ecosystem, former one due to their intrinsic capability of N2-fixation and later because of mineralization of organic matter. Unfortunately, their exposure to variety of abiotic stresses is unavoidable. Comparative analysis of interactive effect of UV-B and heavy metals (Cd/Zn) on nitrogen and phosphorus metabolism of three cyanobacteria (Anabaena, Microcystis, Nostoc) revealed additive inhibition (χ(2) significant p < 0.05) of NH4(+) and PO4(3-) uptake whereas increase in nitrate uptake upon UV-B + heavy metal exposure. Glutamine synthetase and Alkaline phosphatase activity was reduced after all treatments whereas Nitrate reductase activity showed slight stimulation in UV-B and UV-B + heavy metals treatment. Combination of UV-B and metals seems more detrimental to the NH4(+), PO4(3-) uptake, GS and APA activity. A significant stimulation in NO3(-) uptake and NR activity following exposure to UV-B in all the three cyanobacteria suggests UV-B-induced structural change(s) in the enzyme/carriers. Metals seem to compete for the binding sites of the enzymes and carriers; as noticed for Anabaena and Microcystis showing change in Km while no change in the Km value of Nostoc suggests non-competitive nutrient uptake. Higher accumulation and more adverse effect on Na(+) and K(+) efflux proposes Cd as more toxic compared to Zn. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Compartmentalized cyanophycin metabolism in the diazotrophic filaments of a heterocyst-forming cyanobacterium

PubMed Central

Burnat, Mireia; Herrero, Antonia; Flores, Enrique

2014-01-01

Heterocyst-forming cyanobacteria are multicellular organisms in which growth requires the activity of two metabolically interdependent cell types, the vegetative cells that perform oxygenic photosynthesis and the dinitrogen-fixing heterocysts. Vegetative cells provide the heterocysts with reduced carbon, and heterocysts provide the vegetative cells with fixed nitrogen. Heterocysts conspicuously accumulate polar granules made of cyanophycin [multi-L-arginyl-poly (L-aspartic acid)], which is synthesized by cyanophycin synthetase and degraded by the concerted action of cyanophycinase (that releases β-aspartyl-arginine) and isoaspartyl dipeptidase (that produces aspartate and arginine). Cyanophycin synthetase and cyanophycinase are present at high levels in the heterocysts. Here we created a deletion mutant of gene all3922 encoding isoaspartyl dipeptidase in the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. The mutant accumulated cyanophycin and β-aspartyl-arginine, and was impaired specifically in diazotrophic growth. Analysis of an Anabaena strain bearing an All3922-GFP (green fluorescent protein) fusion and determination of the enzyme activity in specific cell types showed that isoaspartyl dipeptidase is present at significantly lower levels in heterocysts than in vegetative cells. Consistently, isolated heterocysts released substantial amounts of β-aspartyl-arginine. These observations imply that β-aspartyl-arginine produced from cyanophycin in the heterocysts is transferred intercellularly to be hydrolyzed, producing aspartate and arginine in the vegetative cells. Our results showing compartmentalized metabolism of cyanophycin identify the nitrogen-rich molecule β-aspartyl-arginine as a nitrogen vehicle in the unique multicellular system represented by the heterocyst-forming cyanobacteria. PMID:24550502

Compartmentalized cyanophycin metabolism in the diazotrophic filaments of a heterocyst-forming cyanobacterium.

PubMed

Burnat, Mireia; Herrero, Antonia; Flores, Enrique

2014-03-11

Heterocyst-forming cyanobacteria are multicellular organisms in which growth requires the activity of two metabolically interdependent cell types, the vegetative cells that perform oxygenic photosynthesis and the dinitrogen-fixing heterocysts. Vegetative cells provide the heterocysts with reduced carbon, and heterocysts provide the vegetative cells with fixed nitrogen. Heterocysts conspicuously accumulate polar granules made of cyanophycin [multi-L-arginyl-poly (L-aspartic acid)], which is synthesized by cyanophycin synthetase and degraded by the concerted action of cyanophycinase (that releases β-aspartyl-arginine) and isoaspartyl dipeptidase (that produces aspartate and arginine). Cyanophycin synthetase and cyanophycinase are present at high levels in the heterocysts. Here we created a deletion mutant of gene all3922 encoding isoaspartyl dipeptidase in the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. The mutant accumulated cyanophycin and β-aspartyl-arginine, and was impaired specifically in diazotrophic growth. Analysis of an Anabaena strain bearing an All3922-GFP (green fluorescent protein) fusion and determination of the enzyme activity in specific cell types showed that isoaspartyl dipeptidase is present at significantly lower levels in heterocysts than in vegetative cells. Consistently, isolated heterocysts released substantial amounts of β-aspartyl-arginine. These observations imply that β-aspartyl-arginine produced from cyanophycin in the heterocysts is transferred intercellularly to be hydrolyzed, producing aspartate and arginine in the vegetative cells. Our results showing compartmentalized metabolism of cyanophycin identify the nitrogen-rich molecule β-aspartyl-arginine as a nitrogen vehicle in the unique multicellular system represented by the heterocyst-forming cyanobacteria.

Azolla-Anabaena Relationship 1

PubMed Central

Meeks, John C.; Steinberg, Nisan A.; Enderlin, Carol S.; Joseph, Cecillia M.; Peters, Gerald A.

1987-01-01

The major radioactive products of the fixation of [13N]N2 by Azolla caroliniana Willd.-Anabaena azollae Stras. were ammonium, glutamine, and glutamate, plus a small amount of alanine. Ammonium accounted for 70 and 32% of the total radioactivity recovered after fixation for 1 and 10 minutes, respectively. The presence of a substantial pool of [13N]N2-derived 13NH4+ after longer incubation periods was attributed to the spatial separation between the site of N2-fixation (Anabaena) and a second, major site of assimilation (Azolla). Initially, glutamine was the most highly radioactive organic product formed from [13N]N2, but after 10 minutes of fixation glutamate had 1.5 times more radiolabel than glutamine. These kinetics of radiolabeling, along with the effects of inhibitors of glutamine synthetase and glutamate synthase on assimilation of exogenous and [13N]N2-derived 13NH4+, indicate that ammonium assimilation occurred by the glutamate synthase cycle and that glutamate dehydrogenase played little or no role in the synthesis of glutamate by Azolla-Anabaena. PMID:16665538

Expression of foreign genes in filamentous cyanobacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuritz, T.; Wolk, C.P.

1993-06-01

Several advantages make cyanobacteria attractive hosts for biodegradative genes and possibly for other exogenous genes that have practical uses. The authors have obtained expression in Anabaena sp. strain PCC 7120 and Nostoc ellipsosporum of a dechlorination operon, fcbAB, from Arthrobacter globiformis, and have also developed a simple method for qualitative assessment of dechlorination by microorganisms, such as cyanobacteria, whose metabolism is dependent on the presence of chloride in the medium. Transcription of fcbAB under the control of a variety of promoters was monitored by placing luxAB (encoding luciferase) downstream from fcbAB, and by measuring light emission from luciferase. They believemore » that the system that they have described has value as a means to screen for factors influencing transcription of foreign genes in cyanobacteria.« less

Cyanobacteria as a Source for Novel Anti-Leukemic Compounds.

PubMed

Humisto, Anu; Herfindal, Lars; Jokela, Jouni; Karkman, Antti; Bjørnstad, Ronja; Choudhury, Romi R; Sivonen, Kaarina

2016-01-01

Cyanobacteria are an inspiring source of bioactive secondary metabolites. These bioactive agents are a diverse group of compounds which are varying in their bioactive targets, the mechanisms of action, and chemical structures. Cyanobacteria from various environments, especially marine benthic cyanobacteria, are found to be rich sources for the search for novel bioactive compounds. Several compounds with anticancer activities have been discovered from cyanobacteria and some of these have succeeded to enter the clinical trials. Varying anticancer agents are needed to overcome increasing challenges in cancer treatments. Different search methods are used to reveal anticancer compounds from natural products, but cell based methods are the most common. Cyanobacterial bioactive compounds as agents against acute myeloid leukemia are not well studied. Here we examined our new results combined with previous studies of anti-leukemic compounds from cyanobacteria with emphasis to reveal common features in strains producing such activity. We report that cyanobacteria harbor specific anti-leukemic compounds since several studied strains induced apoptosis against AML cells but were inactive against non-malignant cells like hepatocytes. We noted that particularly benthic strains from the Baltic Sea, such as Anabaena sp., were especially potential AML apoptosis inducers. Taken together, this review and re-analysis of data demonstrates the power of maintaining large culture collections for the search for novel bioactivities, and also how anti-AML activity in cyanobacteria can be revealed by relatively simple and low-cost assays.

Viruses Infecting a Freshwater Filamentous Cyanobacterium (Nostoc sp.) Encode a Functional CRISPR Array and a Proteobacterial DNA Polymerase B

PubMed Central

Chénard, Caroline; Wirth, Jennifer F.

2016-01-01

ABSTRACT   Here we present the first genomic characterization of viruses infecting Nostoc, a genus of ecologically important cyanobacteria that are widespread in freshwater. Cyanophages A-1 and N-1 were isolated in the 1970s and infect Nostoc sp. strain PCC 7210 but remained genomically uncharacterized. Their 68,304- and 64,960-bp genomes are strikingly different from those of other sequenced cyanophages. Many putative genes that code for proteins with known functions are similar to those found in filamentous cyanobacteria, showing a long evolutionary history in their host. Cyanophage N-1 encodes a CRISPR array that is transcribed during infection and is similar to the DR5 family of CRISPRs commonly found in cyanobacteria. The presence of a host-related CRISPR array in a cyanophage suggests that the phage can transfer the CRISPR among related cyanobacteria and thereby provide resistance to infection with competing phages. Both viruses also encode a distinct DNA polymerase B that is closely related to those found in plasmids of Cyanothece sp. strain PCC 7424, Nostoc sp. strain PCC 7120, and Anabaena variabilis ATCC 29413. These polymerases form a distinct evolutionary group that is more closely related to DNA polymerases of proteobacteria than to those of other viruses. This suggests that the polymerase was acquired from a proteobacterium by an ancestral virus and transferred to the cyanobacterial plasmid. Many other open reading frames are similar to a prophage-like element in the genome of Nostoc sp. strain PCC 7524. The Nostoc cyanophages reveal a history of gene transfers between filamentous cyanobacteria and their viruses that have helped to forge the evolutionary trajectory of this previously unrecognized group of phages. PMID:27302758

The cyanobiont in an Azolla fern is neither Anabaena nor Nostoc.

PubMed

Baker, Judith A; Entsch, Barrie; McKay, David B

2003-12-05

The cyanobacterial symbionts in the fern Azolla have generally been ascribed to either the Anabaena or Nostoc genera. By using comparisons of the sequences of the phycocyanin intergenic spacer and a fragment of the 16S rRNA, we found that the cyanobiont from an Azolla belongs to neither of these genera.

Intercellular Diffusion of a Fluorescent Sucrose Analog via the Septal Junctions in a Filamentous Cyanobacterium

PubMed Central

Nürnberg, Dennis J.; Mariscal, Vicente; Bornikoel, Jan; Nieves-Morión, Mercedes; Krauß, Norbert; Herrero, Antonia

2015-01-01

ABSTRACT Many filamentous cyanobacteria produce specialized nitrogen-fixing cells called heterocysts, which are located at semiregular intervals along the filament with about 10 to 20 photosynthetic vegetative cells in between. Nitrogen fixation in these complex multicellular bacteria depends on metabolite exchange between the two cell types, with the heterocysts supplying combined-nitrogen compounds but dependent on the vegetative cells for photosynthetically produced carbon compounds. Here, we used a fluorescent tracer to probe intercellular metabolite exchange in the filamentous heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. We show that esculin, a fluorescent sucrose analog, is incorporated by a sucrose import system into the cytoplasm of Anabaena cells. The cytoplasmic esculin is rapidly and reversibly exchanged across vegetative-vegetative and vegetative-heterocyst cell junctions. Our measurements reveal the kinetics of esculin exchange and also show that intercellular metabolic communication is lost in a significant fraction of older heterocysts. SepJ, FraC, and FraD are proteins located at the intercellular septa and are suggested to form structures analogous to gap junctions. We show that a ΔsepJ ΔfraC ΔfraD triple mutant shows an altered septum structure with thinner septa but a denser peptidoglycan layer. Intercellular diffusion of esculin and fluorescein derivatives is impaired in this mutant, which also shows a greatly reduced frequency of nanopores in the intercellular septal cross walls. These findings suggest that FraC, FraD, and SepJ are important for the formation of junctional structures that constitute the major pathway for feeding heterocysts with sucrose. PMID:25784700

Complete genome sequence of Anabaena variabilis ATCC 29413

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thiel, Teresa; Pratte, Brenda S.; Zhong, Jinshun

2013-01-01

Anabaena variabilis ATCC 29413 is a filamentous, heterocyst-forming cyanobacterium that has served as a model organism, with an extensive literature extending over 40 years. The strain has three distinct nitrogenases that function under different environmental conditions and is capable of photoautotrophic growth in the light and true heterotrophic growth in the dark using fructose as both carbon and energy source. While this strain was first isolated in 1964 in Mississippi and named Ana-baena flos-aquae MSU A-37, it clusters phylogenetically with cyanobacteria of the genus Nostoc. The strain is a moderate thermophile, growing well at approximately 40 C. Here we providemore » some additional characteristics of the strain, and an analysis of the complete genome sequence.« less

Diversification of DnaA dependency for DNA replication in cyanobacterial evolution.

PubMed

Ohbayashi, Ryudo; Watanabe, Satoru; Ehira, Shigeki; Kanesaki, Yu; Chibazakura, Taku; Yoshikawa, Hirofumi

2016-05-01

Regulating DNA replication is essential for all living cells. The DNA replication initiation factor DnaA is highly conserved in prokaryotes and is required for accurate initiation of chromosomal replication at oriC. DnaA-independent free-living bacteria have not been identified. The dnaA gene is absent in plastids and some symbiotic bacteria, although it is not known when or how DnaA-independent mechanisms were acquired. Here, we show that the degree of dependency of DNA replication on DnaA varies among cyanobacterial species. Deletion of the dnaA gene in Synechococcus elongatus PCC 7942 shifted DNA replication from oriC to a different site as a result of the integration of an episomal plasmid. Moreover, viability during the stationary phase was higher in dnaA disruptants than in wild-type cells. Deletion of dnaA did not affect DNA replication or cell growth in Synechocystis sp. PCC 6803 or Anabaena sp. PCC 7120, indicating that functional dependency on DnaA was already lost in some nonsymbiotic cyanobacterial lineages during diversification. Therefore, we proposed that cyanobacteria acquired DnaA-independent replication mechanisms before symbiosis and such an ancestral cyanobacterium was the sole primary endosymbiont to form a plastid precursor.

Primary light harvesting system: phycobilisomes and associated membranes. Progress report, January 1, 1977--December 31, 1977

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gantt, E.

1977-01-01

Phycobilisomes attached to photosynthetic membranes function as the major light harvesting system in red and blue-green algae. It represents one of the most efficient energy transfer systems in photosynthetic organisms. Allophycocyanin is the terminal pigment in the transfer chain funnelling energy to chlorophyll in all intact phycobilisomes isolated from numerous algal species (Porphyridium cruentum, P. aerugineum, P. sordidum, Rhodosorus marinus, Griffithsia pacifica, Anacystis nidulans, Agmanellum quadruplicatum, Anabaena variabilis, Nostoc sp., Fremyella diplosiphon). Of the several forms of allophycocyanin which exist in dissociated phycobilisomes, the long wavelength form with a fluorescence emission of 675 nm (23/sup 0/C) and 685 (-196/sup 0/C)more » is considered to be the bridging pigment between the phycobilisome and chlorophyll. In Nostoc sp. this form comprises as much as 20 percent of the total allophycocyanin content. Some interconversion between allophycocyanin forms has been observed, which suggests that the same molecule can exist in various conformational or aggregational states. A medium was devised in which energetically active phycobilisome-photosynthetic vesicles were obtained. This is the first step necessary for effective recombination studies of phycobilisomes with membranes and for future exploration of the phycobilisome-membrane binding site.« less

Optimization of Culture Medium for the Growth of Candida sp. and Blastobotrys sp. as Starter Culture in Fermentation of Cocoa Beans (Theobroma cacao) Using Response Surface Methodology (RSM).

PubMed

Mahazar, N H; Zakuan, Z; Norhayati, H; MeorHussin, A S; Rukayadi, Y

2017-01-01

Inoculation of starter culture in cocoa bean fermentation produces consistent, predictable and high quality of fermented cocoa beans. It is important to produce healthy inoculum in cocoa bean fermentation for better fermented products. Inoculum could minimize the length of the lag phase in fermentation. The purpose of this study was to optimize the component of culture medium for the maximum cultivation of Candida sp. and Blastobotrys sp. Molasses and yeast extract were chosen as medium composition and Response Surface Methodology (RSM) was then employed to optimize the molasses and yeast extract. Maximum growth of Candida sp. (7.63 log CFU mL-1) and Blastobotrys sp. (8.30 log CFU mL-1) were obtained from the fermentation. Optimum culture media for the growth of Candida sp., consist of 10% (w/v) molasses and 2% (w/v) yeast extract, while for Blastobotrys sp., were 1.94% (w/v) molasses and 2% (w/v) yeast extract. This study shows that culture medium consists of molasses and yeast extract were able to produce maximum growth of Candida sp. and Blastobotrys sp., as a starter culture for cocoa bean fermentation.

Identification of facultatively heterotrophic, N/sub 2/-fixing cyanobacteria able to receive plasmid vectors from Escherichia coli by conjugation. [Anabaena spp; Nostoc

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flores, E.; Wolk, C.P.

1985-06-01

Plasmid vectors transferable by conjugation from Escherichia coli to obligately photoautotrophic strains of Anabaena spp. are also transferred to and maintained in heterotrophic, filamentous cyanobacteria of the genus Nostoc. These organisms can be used for the genetic analysis of oxygenic photosynthesis, chromatic adaptation, nitrogen fixation, and heterocyst development.

Synergistic Effect of Sarocladium sp. and Cryptococcus sp. Co-Culture on Crude Oil Biodegradation and Biosurfactant Production.

PubMed

Kamyabi, Aliyeh; Nouri, Hoda; Moghimi, Hamid

2017-05-01

This study was conducted to evaluate the co-culture ability of two yeast (Sarocladium sp. and Cryptococcus sp.) isolates as compared to their individual cultures in surfactant production and oil degradation. The results showed that individual culture of each strain was capable of producing surfactant, degrading oil, and pyrene; also, a synergistic effect was observed when a co-culture was applied. Oil removal and biomass production were 28 and 35% higher in the co-culture than in individual cultures, respectively. To investigate the synergistic effects of mix culture on oil degradation, the surface tension, emulsification activity (EA), and cell surface hydrophobicity of individual and co-culture were studied. A comparison between the produced biosurfactant and chemical surfactants showed that individual culture of each yeast strain could reduce the surface tension like SDS and about 10% better than Tween 80. The results showed that the microbial consortium could reduce the surface tension more, by 10 and 20%, than SDS and Tween 80, respectively. Both individual cultures of Sarocladium sp. and Cryptococcus sp. showed good emulsification activity (0.329 and 0.412, respectively) when compared with a non-inoculated medium. Emulsification activity measurement for the two yeast mix cultures showed an excellent 33 and 67% increase as compared to the individual culture of Sarocladium sp. and Cryptococcus sp., respectively. The cell surface hydrophobicity of Sarocladium sp. and Cryptococcus sp. increased (38 and 85%) when the cells were treated with pyrene as a hydrophobic substrate for four generations. Finally, a 40% increase for pyrene degradation was measured in a co-culture of the two yeast mix culture. According to the results of the present study, the co-culture system exhibited better performance and this study will enhance the understanding of the synergistic effects of yeast co-culture on oil degradation.

Exposure of phototrophs to 548 days in low Earth orbit: microbial selection pressures in outer space and on early earth

PubMed Central

Cockell, Charles S; Rettberg, Petra; Rabbow, Elke; Olsson-Francis, Karen

2011-01-01

An epilithic microbial community was launched into low Earth orbit, and exposed to conditions in outer space for 548 days on the European Space Agency EXPOSE-E facility outside the International Space Station. The natural phototroph biofilm was augmented with akinetes of Anabaena cylindrica and vegetative cells of Nostoc commune and Chroococcidiopsis. In space-exposed dark controls, two algae (Chlorella and Rosenvingiella spp.), a cyanobacterium (Gloeocapsa sp.) and two bacteria associated with the natural community survived. Of the augmented organisms, cells of A. cylindrica and Chroococcidiopsis survived, but no cells of N. commune. Only cells of Chroococcidiopsis were cultured from samples exposed to the unattenuated extraterrestrial ultraviolet (UV) spectrum (>110 nm or 200 nm). Raman spectroscopy and bright-field microscopy showed that under these conditions the surface cells were bleached and their carotenoids were destroyed, although cell morphology was preserved. These experiments demonstrate that outer space can act as a selection pressure on the composition of microbial communities. The results obtained from samples exposed to >200 nm UV (simulating the putative worst-case UV exposure on the early Earth) demonstrate the potential for epilithic colonization of land masses during that time, but that UV radiation on anoxic planets can act as a strong selection pressure on surface-dwelling organisms. Finally, these experiments have yielded new phototrophic organisms of potential use in biomass and oxygen production in space exploration. PMID:21593797

Exposure of phototrophs to 548 days in low Earth orbit: microbial selection pressures in outer space and on early earth.

PubMed

Cockell, Charles S; Rettberg, Petra; Rabbow, Elke; Olsson-Francis, Karen

2011-10-01

An epilithic microbial community was launched into low Earth orbit, and exposed to conditions in outer space for 548 days on the European Space Agency EXPOSE-E facility outside the International Space Station. The natural phototroph biofilm was augmented with akinetes of Anabaena cylindrica and vegetative cells of Nostoc commune and Chroococcidiopsis. In space-exposed dark controls, two algae (Chlorella and Rosenvingiella spp.), a cyanobacterium (Gloeocapsa sp.) and two bacteria associated with the natural community survived. Of the augmented organisms, cells of A. cylindrica and Chroococcidiopsis survived, but no cells of N. commune. Only cells of Chroococcidiopsis were cultured from samples exposed to the unattenuated extraterrestrial ultraviolet (UV) spectrum (>110 nm or 200 nm). Raman spectroscopy and bright-field microscopy showed that under these conditions the surface cells were bleached and their carotenoids were destroyed, although cell morphology was preserved. These experiments demonstrate that outer space can act as a selection pressure on the composition of microbial communities. The results obtained from samples exposed to >200 nm UV (simulating the putative worst-case UV exposure on the early Earth) demonstrate the potential for epilithic colonization of land masses during that time, but that UV radiation on anoxic planets can act as a strong selection pressure on surface-dwelling organisms. Finally, these experiments have yielded new phototrophic organisms of potential use in biomass and oxygen production in space exploration.

Oxygen availability strongly affects chronological lifespan and thermotolerance in batch cultures of Saccharomyces cerevisiae

PubMed Central

Bisschops, Markus M.; Vos, Tim; Martínez-Moreno, Rubén; Cortés, Pilar T.; Pronk, Jack T.; Daran-Lapujade, Pascale

2015-01-01

Stationary-phase (SP) batch cultures of Saccharomyces cerevisiae, in which growth has been arrested by carbon-source depletion, are widely applied to study chronological lifespan, quiescence and SP-associated robustness. Based on this type of experiments, typically performed under aerobic conditions, several roles of oxygen in aging have been proposed. However, SP in anaerobic yeast cultures has not been investigated in detail. Here, we use the unique capability of S. cerevisiae to grow in the complete absence of oxygen to directly compare SP in aerobic and anaerobic bioreactor cultures. This comparison revealed strong positive effects of oxygen availability on adenylate energy charge, longevity and thermotolerance during SP. A low thermotolerance of anaerobic batch cultures was already evident during the exponential growth phase and, in contrast to the situation in aerobic cultures, was not substantially increased during transition into SP. A combination of physiological and transcriptome analysis showed that the slow post-diauxic growth phase on ethanol, which precedes SP in aerobic, but not in anaerobic cultures, endowed cells with the time and resources needed for inducing longevity and thermotolerance. When combined with literature data on acquisition of longevity and thermotolerance in retentostat cultures, the present study indicates that the fast transition from glucose excess to SP in anaerobic cultures precludes acquisition of longevity and thermotolerance. Moreover, this study demonstrates the importance of a preceding, calorie-restricted conditioning phase in the acquisition of longevity and stress tolerance in SP yeast cultures, irrespective of oxygen availability. PMID:28357268

Retinal is formed from apo-carotenoids in Nostoc sp. PCC7120: in vitro characterization of an apo-carotenoid oxygenase

PubMed Central

Scherzinger, Daniel; Ruch, Sandra; Kloer, Daniel P.; Wilde, Annegret; Al-Babili, Salim

2006-01-01

The sensory rhodopsin from Anabaena (Nostoc) sp. PCC7120 is the first cyanobacterial retinylidene protein identified. Here, we report on NosACO (Nostoc apo-carotenoid oxygenase), encoded by the ORF (open reading frame) all4284, as the candidate responsible for the formation of the required chromophore, retinal. In contrast with the enzymes from animals, NosACO converts β-apo-carotenals instead of β-carotene into retinal in vitro. The identity of the enzymatic products was proven by HPLC and gas chromatography–MS. NosACO exhibits a wide substrate specificity with respect to chain lengths and functional end-groups, converting β-apo-carotenals, (3R)-3-hydroxy-β-apo-carotenals and the corresponding alcohols into retinal and (3R)-3-hydroxyretinal respectively. However, kinetic analyses revealed very divergent Km and Vmax values. On the basis of the crystal structure of SynACO (Synechocystis sp. PCC6803 apo-carotenoid oxygenase), a related enzyme showing similar enzymatic activity, we designed a homology model of the native NosACO. The deduced structure explains the absence of β-carotene-cleavage activity and indicates that NosACO is a monotopic membrane protein. Accordingly, NosACO could be readily reconstituted into liposomes. To localize SynACO in vivo, a Synechocystis knock-out strain was generated expressing SynACO as the sole carotenoid oxygenase. Western-blot analyses showed that the main portion of SynACO occurred in a membrane-bound form. PMID:16759173

Removal of Anabaena flos-aquae in water treatment process using Moringa oleifera and assessment of fatty acid profile of generated sludge.

PubMed

Moreti, Livia O R; Coldebella, Priscila Ferri; Camacho, Franciele P; Carvalho Bongiovani, Milene; Pereira de Souza, Aloisio Henrique; Kirie Gohara, Aline; Matsushita, Makoto; Fernandes Silva, Marcela; Nishi, Letícia; Bergamasco, Rosângela

2016-01-01

This study aimed to evaluate the efficiency of the coagulation/flocculation/dissolved air flotation (C/F/DAF) process using the coagulant Moringa oleifera (MO) seed powder, and to analyse the profile of fatty acids present in the generated sludge after treatment. For the tests, deionized water artificially contaminated with cell cultures of Anabaena flos-aquae was used, with a cell density in the order of 10(4) cells mL(-1). C/F/DAF tests were conducted using 'Flotest' equipment. For fatty acid profile analyses, a gas chromatograph equipped with a flame ionization detector was used. It was seen that the optimal dosage (100 mg L(-1)) of MO used in the C/F/DAF process was efficient at removing nearly all A. flos-aquae cells (96.4%). The sludge obtained after treatment contained oleic acid (61.7%) and palmitic acid (10.8%). Thus, a water treatment process using C/F/DAF linked to integral MO powder seed was found to be efficient in removing cells of cyanobacteria, and produced a sludge rich in oleic acid that is a precursor favourable for obtaining quality biodiesel, thus becoming an alternative application for the recycling of such biomass.

Attachment of toxigenic Vibrio cholerae 01 to various freshwater plants and survival with a filamentous green alga, Rhizoclonium fontanum.

PubMed

Islam, M S; Drasar, B S; Bradley, D J

1989-12-01

In Bangladesh, cholera epidemics occur twice a year. V. cholerae 01 are readily isolated from the environment only during epidemics. The interepidemic reservoirs or sites of survival and multiplication of V. cholerae are still unknown. Investigations were carried out with various fresh-water plants as possible reservoirs of V. cholerae in the environment. Attachment to and acute population changes of V. cholerae on various plant surfaces was used as a screening technique to screen a particular plant species for survival studies. Five plant species, Anabaena variabilis, Rhizoclonium fontanum, Cladophora sp., Fontinalis antipyretica and Elodea canadensis were used for attachment experiments. Among these plants, R. fontanum showed the best attachment. On the basis of attachment results, survival experiments were carried out with R. fontanum. At 0.05% salinity toxigenic V. cholerae 01 survive longer in the presence of R. fontanum than in medium without algae.

Photosynthetic production of hydrogen. [Blue-green alga, Anabaena cylindrica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neil, G.; Nicholas, D.J.D.; Bockris, J.O.

A systematic investigation of photosynthetic hydrogen production using a blue-green alga, Anabaena cylindrica, was carried out. The results indicate that there are two important problems which must be overcome for large-scale hydrogen production using photosynthetic processes. These are (a) the development of a stable system, and (b) attainment of at least a fifty-fold increase in the rate of hydrogen evolution per unit area illuminated.

Cell wall amidase AmiC1 is required for cellular communication and heterocyst development in the cyanobacterium Anabaena PCC 7120 but not for filament integrity.

PubMed

Berendt, Susanne; Lehner, Josef; Zhang, Yao Vincent; Rasse, Tobias M; Forchhammer, Karl; Maldener, Iris

2012-10-01

Filamentous cyanobacteria of the order Nostocales display typical properties of multicellular organisms. In response to nitrogen starvation, some vegetative cells differentiate into heterocysts, where fixation of N(2) takes place. Heterocysts provide a micro-oxic compartment to protect nitrogenase from the oxygen produced by the vegetative cells. Differentiation involves fundamental remodeling of the gram-negative cell wall by deposition of a thick envelope and by formation of a neck-like structure at the contact site to the vegetative cells. Cell wall-hydrolyzing enzymes, like cell wall amidases, are involved in peptidoglycan maturation and turnover in unicellular bacteria. Recently, we showed that mutation of the amidase homologue amiC2 gene in Nostoc punctiforme ATCC 29133 distorts filament morphology and function. Here, we present the functional characterization of two amiC paralogues from Anabaena sp. strain PCC 7120. The amiC1 (alr0092) mutant was not able to differentiate heterocysts or to grow diazotrophically, whereas the amiC2 (alr0093) mutant did not show an altered phenotype under standard growth conditions. In agreement, fluorescence recovery after photobleaching (FRAP) studies showed a lack of cell-cell communication only in the AmiC1 mutant. Green fluorescent protein (GFP)-tagged AmiC1 was able to complement the mutant phenotype to wild-type properties. The protein localized in the septal regions of newly dividing cells and at the neck region of differentiating heterocysts. Upon nitrogen step-down, no mature heterocysts were developed in spite of ongoing heterocyst-specific gene expression. These results show the dependence of heterocyst development on amidase function and highlight a pivotal but so far underestimated cellular process, the remodeling of peptidoglycan, for the biology of filamentous cyanobacteria.

Clear differences in metabolic and morphological adaptations of akinetes of two Nostocales living in different habitats.

PubMed

Perez, Rebeca; Forchhammer, Karl; Salerno, Graciela; Maldener, Iris

2016-02-01

Akinetes are resting spore-like cells formed by some heterocyst-forming filamentous cyanobacteria for surviving long periods of unfavourable conditions. We studied the development of akinetes in two model strains of cyanobacterial cell differentiation, the planktonic freshwater Anabaena variabilis ATCC 29413 and the terrestrial or symbiotic Nostoc punctiforme ATCC 29133, in response to low light and phosphate starvation. The best trigger of akinete differentiation of Anabaena variabilis was low light; that of N. punctiforme was phosphate starvation. Light and electron microscopy revealed that akinetes of both species differed from vegetative cells by their larger size, different cell morphology and large number of intracellular granules. Anabaena variabilis akinetes had a multilayer envelope; those of N. punctiforme had a simpler envelope. During akinete development of Anabaena variabilis, the amount of the storage compounds cyanophycin and glycogen increased transiently, whereas in N. punctiforme, cyanophycin and lipid droplets increased transiently. Photosynthesis and respiration decreased during akinete differentiation in both species, and remained at a low level in mature akinetes. The clear differences in the metabolic and morphological adaptations of akinetes of the two species could be related to their different lifestyles. The results pave the way for genetic and functional studies of akinete differentiation in these species.

Cyanobacteria associated with Anopheles albimanus (Diptera: Culicidae) larval habitats in southern Mexico.

PubMed

Vázquez-Martínez, M Guadalupe; Rodríguez, Mario H; Arredondo-Jiménez, Juan I; Méndez-Sanchez, José D; Bond-Compeán, J Guillermo; Cold-Morgan, Michelle

2002-11-01

Cyanobacteria associated with Anopheles albimanus Wiedemann larval habitats from southern Chiapas, Mexico, were isolated and identified from water samples and larval midguts using selective medium BG-11. Larval breeding sites were classified according to their hydrology and dominant vegetation. Cyanobacteria isolated in water samples were recorded and analyzed according to hydrological and vegetation habitat breeding types, and mosquito larval abundance. In total, 19 cyanobacteria species were isolated from water samples. Overall, the most frequently isolated cyanobacterial taxa were Phormidium sp., Oscillatoria sp., Aphanocapsa cf. littoralis, Lyngbya lutea, P. animalis, and Anabaena cf. spiroides. Cyanobacteria were especially abundant in estuaries, irrigation canals, river margins and mangrove lagoons, and more cyanobacteria were isolated from Brachiaria mutica, Ceratophyllum demersum, and Hymenachne amplexicaulis habitats. Cyanobacteria were found in habitats with low to high An. albimanus larval abundance, but Aphanocapsa cf. littoralis was associated with habitats of low larval abundance. No correlation was found between water chemistry parameters and the presence of cyanobacteria, however, water temperature (29.2-29.4 degrees C) and phosphate concentration (79.8-136.5 ppb) were associated with medium and high mosquito larvae abundance. In An. albimanus larval midguts, only six species of cyanobacteria were isolated, the majority being from the most abundant cyanobacteria in water samples.

Transcription and Regulation of the Bidirectional Hydrogenase in the Cyanobacterium Nostoc sp. Strain PCC 7120▿

PubMed Central

Sjöholm, Johannes; Oliveira, Paulo; Lindblad, Peter

2007-01-01

The filamentous, heterocystous cyanobacterium Nostoc sp. strain PCC 7120 (Anabaena sp. strain PCC 7120) possesses an uptake hydrogenase and a bidirectional enzyme, the latter being capable of catalyzing both H2 production and evolution. The completely sequenced genome of Nostoc sp. strain PCC 7120 reveals that the five structural genes encoding the bidirectional hydrogenase (hoxEFUYH) are separated in two clusters at a distance of approximately 8.8 kb. The transcription of the hox genes was examined under nitrogen-fixing conditions, and the results demonstrate that the cluster containing hoxE and hoxF can be transcribed as one polycistronic unit together with the open reading frame alr0750. The second cluster, containing hoxU, hoxY, and hoxH, is transcribed together with alr0763 and alr0765, located between the hox genes. Moreover, alr0760 and alr0761 form an additional larger operon. Nevertheless, Northern blot hybridizations revealed a rather complex transcription pattern in which the different hox genes are expressed differently. Transcriptional start points (TSPs) were identified 66 and 57 bp upstream from the start codon of alr0750 and hoxU, respectively. The transcriptions of the two clusters containing the hox genes are both induced under anaerobic conditions concomitantly with the induction of a higher level of hydrogenase activity. An additional TSP, within the annotated alr0760, 244 bp downstream from the suggested translation start codon, was identified. Electrophoretic mobility shift assays with purified LexA from Nostoc sp. strain PCC 7120 demonstrated specific interactions between the transcriptional regulator and both hox promoter regions. However, when LexA from Synechocystis sp. strain PCC 6803 was used, the purified protein interacted only with the promoter region of the alr0750-hoxE-hoxF operon. A search of the whole Nostoc sp. strain PCC 7120 genome demonstrated the presence of 216 putative LexA binding sites in total, including recA and recF. This indicates that, in addition to the bidirectional hydrogenase gene, a number of other genes, including open reading frames connected to DNA replication, recombination, and repair, may be part of the LexA regulatory network in Nostoc sp. strain PCC 7120. PMID:17630298

Sulfur deficiency changes mycosporine-like amino acid (MAA) composition of Anabaena variabilis PCC 7937: a possible role of sulfur in MAA bioconversion.

PubMed

Singh, Shailendra P; Klisch, Manfred; Sinha, Rajeshwar P; Häder, Donat-Peter

2010-01-01

In the present investigation we show for the first time that bioconversion of a primary mycosporine-like amino acid (MAA) into a secondary MAA is regulated by sulfur deficiency in the cyanobacterium Anabaena variabilis PCC 7937. This cyanobacterium synthesizes the primary MAA shinorine (RT = 2.2 min, lambda(max) = 334 nm) under normal conditions (PAR + UV-A + UV-B); however, under sulfur deficiency, a secondary MAA palythine-serine (RT = 3.9 min, lambda(max) = 320 nm) appears. Addition of methionine to sulfur-deficient cultures resulted in the disappearance of palythine-serine, suggesting the role of primary MAAs under sulfur deficiency in recycling of methionine by donating the methyl group from the glycine subunit of shinorine to tetrahydrofolate to regenerate the methionine from homocysteine. This is also the first report for the synthesis of palythine-serine by cyanobacteria which has so far been reported only from corals. Addition of methionine also affected the conversion of mycosporine-glycine into shinorine, consequently, resulted in the appearance of mycosporine-glycine (RT = 3.6 min, lambda(max) = 310 nm). Our results also suggest that palythine-serine is synthesized from shinorine. Based on these results we propose that glycine decarboxylase is the potential enzyme that catalyzes the bioconversion of shinorine to palythine-serine by decarboxylation and demethylation of the glycine unit of shinorine.

Pathophysiology and Toxicokinetic Studies of Blue-Green Algae Intoxication in the Swine Model

DTIC Science & Technology

1989-09-26

In that study a ratio of L� of toxin to CTR infused into similar in situ rat gut loop preparations ameliorated the toxicoses and the liver weights...that had been produced and extracted from laboratory grown Anabaena flos- aguae NCR-525-17, paraoxon, or a control solution. Each of the 5 treatments was...Carmichael, W. W. (1987) Anatoxin-a(s), an 3 anticholinesterase from the cyanobacterium Anabaena flos- aguae NRC-525-17. Toxicon 25:1221. 3 Matsunaga, S

Removal of Anabaena spiroides by potassium permanganate pre-oxidation: effect on photosynthetic capacity and molecular weight distribution.

PubMed

Qiao, Junlian; Zhang, Xiaodong; Lv, Liping

2017-11-01

Bench scale tests were conducted to investigate the effect of potassium permanganate pre-oxidation on the photosynthetic activity and molecular weight distribution of Anabaena spiroides. Different concentrations of potassium permanganate were added into the suspension of Anabaena spiroides, one of the dominant algae in water bloom, and after pre-oxidation of permanganate for 1 h, the results show that the removal rate significantly increases by 33.99~36.35% compared to direct coagulation. Then, the algal characteristics, including photosynthetic ability, the changes in extracellular organic matter three-dimensional fluorescence, and the distribution of molecular weight were conducted and the results show that along with increasing concentration of potassium permanganate, the photosynthetic ability of algae decreases, more extracellular organic matter is secreted, and large molecular weight matter (humic-like and fulvic-like substances) are generated. Therefore, this study demonstrates that potassium permanganate could be used in addressing the algae-rich water.

Plant-fed versus chemicals-fed rhizobacteria of Lucerne: Plant-only teabags culture media not only increase culturability of rhizobacteria but also recover a previously uncultured Lysobacter sp., Novosphingobium sp. and Pedobacter sp.

PubMed

Hegazi, Nabil A; Sarhan, Mohamed S; Fayez, Mohamed; Patz, Sascha; Murphy, Brian R; Ruppel, Silke

2017-01-01

In an effort to axenically culture the previously uncultivable populations of the rhizobacteria of Lucerne (Medicago sativa L.), we propose plant-only teabags culture media to mimic the nutritional matrix available in the rhizosphere. Here, we show that culture media prepared from Lucerne powder teabags substantially increased the cultivability of Lucerne rhizobacteria compared with a standard nutrient agar, where we found that the cultivable populations significantly increased by up to 60% of the total bacterial numbers as estimated by Quantitative Real-time Polymerase Chain Reaction (qRT-PCR). Cluster analysis of 16S rDNA Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) of cultivable Colony-Forming Units (CFUs) revealed a more distinct composition and separation of bacterial populations recovered on the plant-only teabags culture media than those developed on a standard nutrient agar. Further, the new plant medium gave preference to the micro-symbiont Sinorhizobium meliloti, and succeeded in isolating a number of not-yet-cultured bacteria, most closely matched to Novosphingobium sp., Lysobacter sp. and Pedobacter sp. The present study may encourage other researchers to consider moving from the well-established standard culture media to the challenging new plant-only culture media. Such a move may reveal previously hidden members of rhizobacteria, and help to further explore their potential environmental impacts.

Factors influencing the abundance of the side population in a human myeloma cell line.

PubMed

Mo, Sui-Lin; Li, Jia; Loh, Yen S; Brown, Ross D; Smith, Adrian L; Chen, Yuling; Joshua, Douglas; Roufogalis, Basil D; Li, George Q; Fan, Kei; Ng, Michelle C H; Sze, Daniel Man-Yuen

2011-01-01

Side population (SP) refers to a group of cells, which is capable to efflux Hoechst 33342, a DNA-binding dye. SP cells exist both in normal and tumor tissues. Although SP abundance has been used as an indicator for disease prognostic and drug screening in many research projects, few studies have systematically examined the factors influencing SP analysis. In this study we aim to develop a more thorough understanding of the multiple factors involved in SP analysis including Hoechst 33342 staining and cell culture. RPMI-8226, a high SP percentage (SP%) human myeloma cell line was employed here. The results showed that SP% was subject to staining conditions including: viable cell proportion, dye concentration, staining cell density, incubation duration, staining volume, and mix interval. In addition, SP% was highest in day one after passage, while dropped steadily over time. This study shows that both staining conditions and culture duration can significantly affect SP%. In this case, any conclusions based on SP% should be interpreted cautiously. The relation between culture duration and SP% suggests that the incidence of SP cells may be related to cell proliferation and cell cycle phase. Maintaining these technical variables consistently is essential in SP research.

Cultural Explanations of Sleep Paralysis in Italy: The Pandafeche Attack and Associated Supernatural Beliefs.

PubMed

Jalal, Baland; Romanelli, Andrea; Hinton, Devon E

2015-12-01

The current study examines cultural explanations regarding sleep paralysis (SP) in Italy. The study explores (1) whether the phenomenology of SP generates culturally specific interpretations and causal explanations and (2) what are the beliefs and local traditions associated with such cultural explanations. The participants were Italian nationals from the general population (n = 68) recruited in the region of Abruzzo, Italy. All participants had experienced at least one lifetime episode of SP. The sleep paralysis experiences and phenomenology questionnaire were orally administered to participants. We found a multilayered cultural interpretation of SP, namely the Pandafeche attack, associated with various supernatural beliefs. Thirty-eight percent of participants believed that this supernatural being, the Pandafeche-often referred to as an evil witch, sometimes as a ghost-like spirit or a terrifying humanoid cat-might have caused their SP. Twenty-four percent of all participants sensed the Pandafeche was present during their SP. Strategies to prevent Pandafeche attack included sleeping in supine position, placing a broom by the bedroom door, or putting a pile of sand by the bed. Case studies are presented to illustrate the study findings. The Pandafeche attack thus constitutes a culturally specific, supernatural interpretation of the phenomenology of SP in the Abruzzo region of Italy.

Light Driven CO2 Fixation by Using Cyanobacterial Photosystem I and NADPH-Dependent Formate Dehydrogenase

PubMed Central

Ihara, Masaki; Kawano, Yusuke; Urano, Miho; Okabe, Ayako

2013-01-01

The ultimate goal of this research is to construct a new direct CO2 fixation system using photosystems in living algae. Here, we report light-driven formate production from CO2 by using cyanobacterial photosystem I (PS I). Formate, a chemical hydrogen carrier and important industrial material, can be produced from CO2 by using the reducing power and the catalytic function of formate dehydrogenase (FDH). We created a bacterial FDH mutant that experimentally switched the cofactor specificity from NADH to NADPH, and combined it with an in vitro-reconstituted cyanobacterial light-driven NADPH production system consisting of PS I, ferredoxin (Fd), and ferredoxin-NADP+-reductase (FNR). Consequently, light-dependent formate production under a CO2 atmosphere was successfully achieved. In addition, we introduced the NADPH-dependent FDH mutant into heterocysts of the cyanobacterium Anabaena sp. PCC 7120 and demonstrated an increased formate concentration in the cells. These results provide a new possibility for photo-biological CO2 fixation. PMID:23936519

Light driven CO2 fixation by using cyanobacterial photosystem I and NADPH-dependent formate dehydrogenase.

PubMed

Ihara, Masaki; Kawano, Yusuke; Urano, Miho; Okabe, Ayako

2013-01-01

The ultimate goal of this research is to construct a new direct CO2 fixation system using photosystems in living algae. Here, we report light-driven formate production from CO2 by using cyanobacterial photosystem I (PS I). Formate, a chemical hydrogen carrier and important industrial material, can be produced from CO2 by using the reducing power and the catalytic function of formate dehydrogenase (FDH). We created a bacterial FDH mutant that experimentally switched the cofactor specificity from NADH to NADPH, and combined it with an in vitro-reconstituted cyanobacterial light-driven NADPH production system consisting of PS I, ferredoxin (Fd), and ferredoxin-NADP(+)-reductase (FNR). Consequently, light-dependent formate production under a CO2 atmosphere was successfully achieved. In addition, we introduced the NADPH-dependent FDH mutant into heterocysts of the cyanobacterium Anabaena sp. PCC 7120 and demonstrated an increased formate concentration in the cells. These results provide a new possibility for photo-biological CO2 fixation.

Role of calcium in acclimation of the cyanobacterium Synechococcus elongatus PCC 7942 to nitrogen starvation.

PubMed

Leganés, Francisco; Forchhammer, Karl; Fernández-Piñas, Francisca

2009-01-01

A Ca2+ signal is required for the process of heterocyst differentiation in the filamentous diazotrophic cyanobacterium Anabaena sp. PCC 7120. This paper presents evidence that a transient increase in intracellular free Ca2+ is also involved in acclimation to nitrogen starvation in the unicellular non-diazotrophic cyanobacterium Synechococcus elongatus PCC 7942. The Ca2+ transient was triggered in response to nitrogen step-down or the addition of 2-oxoglutarate (2-OG), or its analogues 2,2-difluoropentanedioic acid (DFPA) and 2-methylenepentanedioic acid (2-MPA), to cells growing with combined nitrogen, suggesting that an increase in intracellular 2-OG levels precedes the Ca2+ transient. The signalling protein P(II) and the transcriptional regulator NtcA appear to be needed to trigger the signal. Suppression of the Ca2+ transient by the intracellular Ca2+ chelator N,N'-[1,2-ethanediylbis(oxy-2,1-phenylene)]bis[N-[2-[(acetyloxy)methoxy]-2-oxoethyl

New Anabaena and Nostoc cyanophages from sewage settling ponds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, N.; Thiel, T.; Giddings, T.H., Jr.

1981-10-15

We have isolated, from sewage settling ponds, 16 cyanophages for heterocyst forming, filamentous cyanobacteria of the genera Anabaena and Nostoc. These phages fall into three groups based on morphology, host range, one-step growth curves, and restriction digests. On the basis of these criteria they can be distinguished from cyanophages A-1(L), A-4(L), N-1, and AN-10 which we received from other laboratories. Certain of the newly described phages are similar in morphology to the short-tailed LPP cyanophages, and others to the long-tailed AS cyanophages.

Degradation of textile dyes by cyanobacteria.

PubMed

Dellamatrice, Priscila Maria; Silva-Stenico, Maria Estela; Moraes, Luiz Alberto Beraldo de; Fiore, Marli Fátima; Monteiro, Regina Teresa Rosim

Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Genomic Survey and Biochemical Analysis of Recombinant Candidate Cyanobacteriochromes Reveals Enrichment for Near UV/Violet Sensors in the Halotolerant and Alkaliphilic Cyanobacterium Microcoleus IPPAS B353*

PubMed Central

Cho, Sung Mi; Jeoung, Sae Chae; Song, Ji-Young; Kupriyanova, Elena V.; Pronina, Natalia A.; Lee, Bong-Woo; Jo, Seong-Whan; Park, Beom-Seok; Choi, Sang-Bong; Song, Ji-Joon; Park, Youn-Il

2015-01-01

Cyanobacteriochromes (CBCRs), which are exclusive to and widespread among cyanobacteria, are photoproteins that sense the entire range of near-UV and visible light. CBCRs are related to the red/far-red phytochromes that utilize linear tetrapyrrole (bilin) chromophores. Best characterized from the unicellular cyanobacterium Synechocystis sp. PCC 6803 and the multicellular heterocyst forming filamentous cyanobacteria Nostoc punctiforme ATCC 29133 and Anabaena sp. PCC 7120, CBCRs have been poorly investigated in mat-forming, nonheterocystous cyanobacteria. In this study, we sequenced the genome of one of such species, Microcoleus IPPAS B353 (Microcoleus B353), and identified two phytochromes and seven CBCRs with one or more bilin-binding cGMP-specific phosphodiesterase, adenylyl cyclase and FhlA (GAF) domains. Biochemical and spectroscopic measurements of 23 purified GAF proteins from phycocyanobilin (PCB) producing recombinant Escherichia coli indicated that 13 of these proteins formed near-UV and visible light-absorbing covalent adducts: 10 GAFs contained PCB chromophores, whereas three contained the PCB isomer, phycoviolobilin (PVB). Furthermore, the complement of Microcoleus B353 CBCRs is enriched in near-UV and violet sensors, but lacks red/green and green/red CBCRs that are widely distributed in other cyanobacteria. We hypothesize that enrichment in short wavelength-absorbing CBCRs is critical for acclimation to high-light environments where this organism is found. PMID:26405033

Evaluation of biodegradable plastics as solid hydrogen donors for the reductive dechlorination of fthalide by Dehalobacter species.

PubMed

Yoshida, Naoko; Ye, Lizhen; Liu, Fengmao; Li, Zhiling; Katayama, Arata

2013-02-01

Biodegradable plastics (BPs) were evaluated for their applicability as sustainable and solid H(2) donors for microbial reductive dechlorination of 4,5,6,7-tetrachlorophthalide (fthalide). After a screening test of several BPs, the starch-based plastic (SP) that produced the highest levels of H(2) was selected for its use as the sole H(2) donor in this reaction. Fthalide dechlorination was successfully accomplished by combining an H(2)-producing SP culture and a KFL culture containing Dehalobacter species, supplemented with 0.13% and 0.5% SP, respectively. The efficiency of H(2) use in dechlorination was evaluated in a combined culture containing the KFL culture and strain Clostridium sp. Ma13, a new isolate that produces H(2) from SP. Results obtained with this culture indicated increased H(2)-fraction for fthalide dechlorination much more in this culture than in compared with a KFL culture supplemented with 20mM lactate, which are 0.75 H(2)·glucose(-1) and 0.015 H(2)·lactate(-1) in mol ratio, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

Adherent culture conditions enrich the side population obtained from the cochlear modiolus-derived stem/progenitor cells.

PubMed

Chao, Ting-Ting; Wang, Chih-Hung; Chen, Hsin-Chien; Shih, Cheng-Ping; Sytwu, Huey-Kang; Huang, Kun-Lun; Chen, Shao-Yuan

2013-05-01

Previously, our group reported that sphere-forming cells derived from the organ of Corti represent the stem/progenitor cells (SPCs) of the cochlea due to their properties of self-renewal and multipotency. However, long-term propagation of sphere-forming cells under suspension culture conditions may fail to maintain the characteristic stemness of these cells. Therefore, this study investigated whether an adherent culture system would be beneficial in terms of preserving more stem-like cells for long-term manipulations in vitro. Isolated modiolus-derived SPCs were placed on poly-d-lysine-coated petri dishes to form the so-called "adherent" culture system. Modiolus SPCs cultured under adherent conditions exhibited a significantly increased percentage of cells with the side population (SP) phenotype (18.6%) compared with cells cultured under conventional suspension culture conditions (0.8%). Even after repeated passages, modiolus SPCs cultured under adherent culture conditions preserved more SP phenotype cells. In comparison with the non-SP phenotype cells, the sorted SP cells exhibited more stem-like but less differentiated properties, with an upregulated expression of the ATP-binding cassette subfamily G member 2 (ABCG2), Nestin, Sox2, and Nanog proteins. Furthermore, Retinoic acid (RA) treatment confirmed the expression of the multipotent differentiation markers in the SP cells, including TUJ1, pancytokeratin, glial fibrillary acidic protein (GFAP), and p27(Kip1). Employment of an adherent culture system, instead of a suspension culture system, resulted in the enrichment of the SP cells from SPCs while retaining their stemness and multipotency. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Cross-cultural validity and measurement invariance of the Organizational Stressor Indicator for Sport Performers (OSI-SP) across three countries.

PubMed

Arnold, R; Ponnusamy, V; Zhang, C-Q; Gucciardi, D F

2017-08-01

Organizational stressors are a universal phenomenon which can be particularly prevalent and problematic for sport performers. In view of their global existence, it is surprising that no studies have examined cross-cultural differences in organizational stressors. One explanation for this is that the Organizational Stressor Indicator for Sport Performers (OSI-SP; Arnold, Fletcher, & Daniels, 2013), which can comprehensively measure the organizational pressures that sport performers have encountered, has not yet been translated from English into any other languages nor scrutinized cross-culturally. The first purpose of this study, therefore, was to examine the cross-cultural validity of the OSI-SP. In addition, the study aimed to test the equivalence of the OSI-SP's factor structure across cultures. British (n = 379), Chinese (n = 335), and Malaysian (n = 444) sport performers completed the OSI-SP. Confirmatory factor analyses confirmed the cross-cultural validity of the factorial model for the British and Malaysian samples; however, the overall model fit for the Chinese data did not meet all guideline values. Support was provided for the equality of factor loadings, variances, and covariances on the OSI-SP across the British and Malaysian cultures. These findings advance knowledge and understanding on the cross-cultural existence, conceptualization, and operationalization of organizational stressors. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Biodiesel production from microalgal isolates of southern Pakistan and quantification of FAMEs by GC-MS/MS analysis

PubMed Central

2012-01-01

Background Microalgae have attracted major interest as a sustainable source for biodiesel production on commercial scale. This paper describes the screening of six microalgal species, Scenedesmus quadricauda, Scenedesmus acuminatus, Nannochloropsis sp., Anabaena sp., Chlorella sp. and Oscillatoria sp., isolated from fresh and marine water resources of southern Pakistan for biodiesel production and the GC-MS/MS analysis of their fatty acid methyl esters (FAMEs). Results Growth rate, biomass productivity and oil content of each algal species have been investigated under autotrophic condition. Biodiesel was produced from algal oil by acid catalyzed transesterification reaction and resulting fatty acid methyl esters (FAMEs) content was analyzed by GC/MS. Fatty acid profiling of the biodiesel, obtained from various microalgal oils showed high content of C-16:0, C-18:0, cis-Δ9C-18:1, cis-Δ11C-18:1 (except Scenedesmus quadricauda) and 10-hydroxyoctadecanoic (except Scenedesmus acuminatus). Absolute amount of C-14:0, C-16:0 and C-18:0 by a validated GC-MS/MS method were found to be 1.5-1.7, 15.0-42.5 and 4.2-18.4 mg/g, respectively, in biodiesel obtained from various microalgal oils. Biodiesel was also characterized in terms of cetane number, kinematic viscosity, density and higher heating value and compared with the standard values. Conclusion Six microalgae of local origin were screened for biodiesel production. A method for absolute quantification of three important saturated fatty acid methyl esters (C-14, C-16 and C-18) by gas chromatography-tandem mass spectrometry (GC-MS/MS), using multiple reactions monitoring (MRM) mode, was employed for the identification and quantification of biodiesels obtained from various microalgal oils. The results suggested that locally found microalgae can be sustainably harvested for the production of biodiesel. This offers the tremendous economic opportunity for an energy-deficient nation. PMID:23216896

Advantages of Environmental Scanning Electron Microscopy in Studies of Microorganisms

DTIC Science & Technology

1993-01-01

external structures, cultures of Aspergillus sp. and Cunninghamella sp. but details of cytoplasmic organization were lacking were maintained on corn meal ... agar . (Fig. 7). Uncoated, freeze-dried Euglena sp. cells exam- ined with either ESD or BSE detectors did not exhibit Specimen Preparation for ESEM...approximately Agar plugs from sporulating cultures of Cunning- 1.0 pLm in diameter (Fig. 23). Many of the vesicles ap- hamella sp., Mucor sp., and Aspergillus

The contribution of nitrogen fixation by cyanobacteria to particulate organic nitrogen in a constructed wetland

NASA Astrophysics Data System (ADS)

Zhang, X.; PAN, X.; MA, M.; Li, W.; Cui, L.

2016-12-01

N-fixing cyanobacteria can create extra nitrogen for aquatic ecosystems. Previous studies reported inconsistence patterns of the contribution of biological nitrogen fixation to the nitrogen pools in aquatic ecosystems. However, there were few studies concerning the effect of fixed nitrogen by cyanobacteria on the nitrogen removal efficiency in constructed wetlands. This study was performed at the Beijing Wildlife Rescue and Rehabilitation Centre, where a constructed lake for the habitation of waterfowls and a constructed wetland for purifying sewage from the lake are located. The composition of phytoplankton communities, the concentrations of particulate organic nitrogen (PON) and nitrogen fixation rates (Rn) in the constructed lake and the constructed wetland were compared throughout a growing season. We counted the densities of genus Anabaena and Microcystis cells, and explored their relationships with PON and Rn in water. The proportions of PON from various sources, including the ambient N2, waterfowl faeces, wetland sediments and the nitrates, were calculated by the natural abundance of 15N with the IsoSource software. The result revealed that the constructed lake was alternately dominated by Anabaena and Microcystis throughout the growing season, and the Rn was positively correlated with PON and the cell density of Anabaena (P < 0.05). This implied that the fixed nitrogen by N-fixing Anabaena might be utilized by non-N-fixing Microcystis, maintaining the fixed nitrogen with PON form. The ambient N2 composed 0.5 82% and 50.0 84.7% to the PON in the constructed lake and wetland respectively during the growing season. The proportions of PON from N2 increased to more than 80% when the Rn reached the highest in September. The result demonstrated that the nitrogen fixed by Anabaena might be utilized by non-N-fixing Microcystis which formed water blooms in summer. Therefore, the decline of the removal efficiency of PON in the constructed wetland in summer might indirectly result from the nitrogen fixation, since the proliferated algal were difficult to sediment in surface flow wetlands.

Plant-fed versus chemicals-fed rhizobacteria of Lucerne: Plant-only teabags culture media not only increase culturability of rhizobacteria but also recover a previously uncultured Lysobacter sp., Novosphingobium sp. and Pedobacter sp.

PubMed Central

Hegazi, Nabil A.; Sarhan, Mohamed S.; Fayez, Mohamed; Patz, Sascha; Murphy, Brian R.; Ruppel, Silke

2017-01-01

In an effort to axenically culture the previously uncultivable populations of the rhizobacteria of Lucerne (Medicago sativa L.), we propose plant-only teabags culture media to mimic the nutritional matrix available in the rhizosphere. Here, we show that culture media prepared from Lucerne powder teabags substantially increased the cultivability of Lucerne rhizobacteria compared with a standard nutrient agar, where we found that the cultivable populations significantly increased by up to 60% of the total bacterial numbers as estimated by Quantitative Real-time Polymerase Chain Reaction (qRT-PCR). Cluster analysis of 16S rDNA Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) of cultivable Colony-Forming Units (CFUs) revealed a more distinct composition and separation of bacterial populations recovered on the plant-only teabags culture media than those developed on a standard nutrient agar. Further, the new plant medium gave preference to the micro-symbiont Sinorhizobium meliloti, and succeeded in isolating a number of not-yet-cultured bacteria, most closely matched to Novosphingobium sp., Lysobacter sp. and Pedobacter sp. The present study may encourage other researchers to consider moving from the well-established standard culture media to the challenging new plant-only culture media. Such a move may reveal previously hidden members of rhizobacteria, and help to further explore their potential environmental impacts. PMID:28686606

Halobacterium sp. SP1(1) as a starter culture for accelerating fish sauce fermentation.

PubMed

Akolkar, A V; Durai, D; Desai, A J

2010-07-01

Application of Halobacterium sp. SP1(1) for the acceleration of fish sauce fermentation. Traditional fish sauce fermentation was mimicked using Halobacterium sp. SP1(1) as starter culture. Protease activity, peptide release and α-amino content (parameters used to monitor the progress of the fermentation) were high at day 10 in tests and day 20 in un-inoculated controls. The total protein and nitrogen contents were also high in tests compared with controls. The amino acid profile observed at the end of fermentation in experimental samples, when compared with the commercial sauce preparation, was found to be better with respect to flavour and aroma contributing amino acids as well as essential amino acid lysine. Microflora analysis of the final fish sauce revealed the absence of any nonhalophilic or halotolerant micro-organisms. The protease-producing halophilic isolates obtained from the fish sauce of eviscerated and uneviscerated controls were identified as Halobacterium sp. F1 and F2, respectively, by 16S rDNA sequence analysis. Exogenous augmentation of Halobacterium sp. SP1(1) accelerated the fish sauce fermentation process with an additive effect on the existing natural microflora present in the fish during fermentation. Halobacterium sp SP1(1), therefore, can be used as an important starter culture for accelerating the fish fermentation process, which is attributed to its extracellular protease. The present study is the first report on use of Halobacterium species as a starter culture for accelerating fish sauce fermentation. Use of halobacterial starter cultures may revolutionize the process in fish sauce industries by reducing the fermentation time and making the process more economical with improved nutritive value of product. Journal compilation © 2009 The Society for Applied Microbiology. No claim to Indian Government works.

Flavodiiron proteins Flv1 and Flv3 enable cyanobacterial growth and photosynthesis under fluctuating light.

PubMed

Allahverdiyeva, Yagut; Mustila, Henna; Ermakova, Maria; Bersanini, Luca; Richaud, Pierre; Ajlani, Ghada; Battchikova, Natalia; Cournac, Laurent; Aro, Eva-Mari

2013-03-05

Cyanobacterial flavodiiron proteins (FDPs; A-type flavoprotein, Flv) comprise, besides the β-lactamase-like and flavodoxin domains typical for all FDPs, an extra NAD(P)H:flavin oxidoreductase module and thus differ from FDPs in other Bacteria and Archaea. Synechocystis sp. PCC 6803 has four genes encoding the FDPs. Flv1 and Flv3 function as an NAD(P)H:oxygen oxidoreductase, donating electrons directly to O2 without production of reactive oxygen species. Here we show that the Flv1 and Flv3 proteins are crucial for cyanobacteria under fluctuating light, a typical light condition in aquatic environments. Under constant-light conditions, regardless of light intensity, the Flv1 and Flv3 proteins are dispensable. In contrast, under fluctuating light conditions, the growth and photosynthesis of the Δflv1(A) and/or Δflv3(A) mutants of Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120 become arrested, resulting in cell death in the most severe cases. This reaction is mainly caused by malfunction of photosystem I and oxidative damage induced by reactive oxygen species generated during abrupt short-term increases in light intensity. Unlike higher plants that lack the FDPs and use the Proton Gradient Regulation 5 to safeguard photosystem I, the cyanobacterial homolog of Proton Gradient Regulation 5 is shown not to be crucial for growth under fluctuating light. Instead, the unique Flv1/Flv3 heterodimer maintains the redox balance of the electron transfer chain in cyanobacteria and provides protection for photosystem I under fluctuating growth light. Evolution of unique cyanobacterial FDPs is discussed as a prerequisite for the development of oxygenic photosynthesis.

The Effects of Microalgae as Live Food for Brachionus plicatilis (Rotifer) in Intensive Culture System

PubMed Central

Rahman, Abdull Razak Abd; Cob, Zaidi Che; Jamari, Zainoddin; Mohamed, Abdul Majid; Toda, Tatsuki; Ross, Othman Haji

2018-01-01

Brachionus plicatilis is used to feed fish and crustacean larvae in the aquaculture industry. It is well established that the type of microalgae may influence rotifer production. This experiment was conducted to determine the effect of five different locally available microalgae species at Fisheries Research Institute (FRI), Kampung Pulau Sayak, Kedah, Malaysia on the instantaneous growth rate (μ) of rotifer. Nannochloris sp., Tetraselmis sp., Isochrysis sp., Chlorella sp., and Nannochloropsis sp. were used as feed at different algae densities (0.1, 0.3, 0.7 and 1.5 × 106 cells/ml) and culture volumes (20, 70 and 210 ml). At algae densities ranging from 0.3 to 1.5 × 106 cells/ml, an average μ value of more than 0.90 per day were recorded for all algae species. However, at density of 0.1 × 106 cells/ml, only Tetraselmis sp. resulted in the significantly highest μ value compared with others (p < 0.05). In terms of volume, smaller culture volume of Tetraselmis sp. (20 ml) showed significantly higher μ compared with higher volume (70 and 210 ml cultures). PMID:29644020

Growth and Photosynthetic Characteristics of Toxic and Non-Toxic Strains of the Cyanobacteria Microcystis aeruginosa and Anabaena circinalis in Relation to Light

PubMed Central

Islam, M. Ashraful; Beardall, John

2017-01-01

Cyanobacteria are major bloom-forming organisms in freshwater ecosystems and many strains are known to produce toxins. Toxin production requires an investment in energy and resources. As light is one of the most important factors for cyanobacterial growth, any changes in light climate might affect cyanobacterial toxin production as well as their growth and physiology. To evaluate the effects of light on the growth and physiological parameters of both toxic and non-toxic strains of Microcystis aeruginosa and Anabaena circinalis, cultures were grown at a range of light intensities (10, 25, 50, 100, 150 and 200 µmol m−2 s−1). The study revealed that the toxic strains of both species (CS558 for M. aeruginosa and CS537 and CS541 for A. circinalis) showed growth (µ) saturation at a higher light intensity compared to the non-toxic strains (CS338 for M. aeruginosa and CS534 for A. circinalis). Both species showed differences in chlorophyll a, carotenoid, allophycocyanin (APC) and phycoerythrin (PE) content between strains. There were also differences in dark respiration (Rd), light saturated oxygen evolution rates (Pmax) and efficiency of light harvesting (α) between strains. All other physiological parameters showed no statistically significant differences between strains. This study suggest that the different strains respond differently to different light habitats. Thus, changes in light availability may affect bloom intensity of toxic and nontoxic strains of cyanobacteria by changing the dominance and succession patterns. PMID:28777340

Bacterial Anabaena variabilis phenylalanine ammonia lyase: a biocatalyst with broad substrate specificity.

PubMed

Lovelock, Sarah L; Turner, Nicholas J

2014-10-15

Phenylalanine ammonia lyases (PALs) catalyse the regio- and stereoselective hydroamination of cinnamic acid analogues to yield optically enriched α-amino acids. Herein, we demonstrate that a bacterial PAL from Anabaena variabilis (AvPAL) displays significantly higher activity towards a series of non-natural substrates than previously described eukaryotic PALs. Biotransformations performed on a preparative scale led to the synthesis of the 2-chloro- and 4-trifluoromethyl-phenylalanine derivatives in excellent ee, highlighting the enormous potential of bacterial PALs as biocatalysts for the synthesis of high value, non-natural amino acids. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimizing cyanobacteria growth conditions in a sealed environment to enable chemical inhibition tests with volatile chemicals.

PubMed

Johnson, Tylor J; Zahler, Jacob D; Baldwin, Emily L; Zhou, Ruanbao; Gibbons, William R

2016-07-01

Cyanobacteria are currently being engineered to photosynthetically produce next-generation biofuels and high-value chemicals. Many of these chemicals are highly toxic to cyanobacteria, thus strains with increased tolerance need to be developed. The volatility of these chemicals may necessitate that experiments be conducted in a sealed environment to maintain chemical concentrations. Therefore, carbon sources such as NaHCO3 must be used for supporting cyanobacterial growth instead of CO2 sparging. The primary goal of this study was to determine the optimal initial concentration of NaHCO3 for use in growth trials, as well as if daily supplementation of NaHCO3 would allow for increased growth. The secondary goal was to determine the most accurate method to assess growth of Anabaena sp. PCC 7120 in a sealed environment with low biomass titers and small sample volumes. An initial concentration of 0.5g/L NaHCO3 was found to be optimal for cyanobacteria growth, and fed-batch additions of NaHCO3 marginally improved growth. A separate study determined that a sealed test tube environment is necessary to maintain stable titers of volatile chemicals in solution. This study also showed that a SYTO® 9 fluorescence-based assay for cell viability was superior for monitoring filamentous cyanobacterial growth compared to absorbance, chlorophyll α (chl a) content, and biomass content due to its accuracy, small sampling size (100μL), and high throughput capabilities. Therefore, in future chemical inhibition trials, it is recommended that 0.5g/L NaHCO3 is used as the carbon source, and that culture viability is monitored via the SYTO® 9 fluorescence-based assay that requires minimum sample size. Copyright © 2016 Elsevier B.V. All rights reserved.

Production of induced secondary metabolites by a co-culture of sponge-associated actinomycetes, Actinokineospora sp. EG49 and Nocardiopsis sp. RV163.

PubMed

Dashti, Yousef; Grkovic, Tanja; Abdelmohsen, Usama Ramadan; Hentschel, Ute; Quinn, Ronald J

2014-05-22

Two sponge-derived actinomycetes, Actinokineospora sp. EG49 and Nocardiopsis sp. RV163, were grown in co-culture and the presence of induced metabolites monitored by ¹H NMR. Ten known compounds, including angucycline, diketopiperazine and β-carboline derivatives 1-10, were isolated from the EtOAc extracts of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163. Co-cultivation of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163 induced the biosynthesis of three natural products that were not detected in the single culture of either microorganism, namely N-(2-hydroxyphenyl)-acetamide (11), 1,6-dihydroxyphenazine (12) and 5a,6,11a,12-tetrahydro-5a,11a-dimethyl[1,4]benzoxazino[3,2-b][1,4]benzoxazine (13a). When tested for biological activity against a range of bacteria and parasites, only the phenazine 12 was active against Bacillus sp. P25, Trypanosoma brucei and interestingly, against Actinokineospora sp. EG49. These findings highlight the co-cultivation approach as an effective strategy to access the bioactive secondary metabolites hidden in the genomes of marine actinomycetes.

The Effects of Microalgae as Live Food for Brachionus plicatilis (Rotifer) in Intensive Culture System.

PubMed

Rahman, Abdull Razak Abd; Cob, Zaidi Che; Jamari, Zainoddin; Mohamed, Abdul Majid; Toda, Tatsuki; Ross, Othman Haji

2018-03-01

Brachionus plicatilis is used to feed fish and crustacean larvae in the aquaculture industry. It is well established that the type of microalgae may influence rotifer production. This experiment was conducted to determine the effect of five different locally available microalgae species at Fisheries Research Institute (FRI), Kampung Pulau Sayak, Kedah, Malaysia on the instantaneous growth rate (μ) of rotifer. Nannochloris sp., Tetraselmis sp., Isochrysis sp., Chlorella sp., and Nannochloropsis sp. were used as feed at different algae densities (0.1, 0.3, 0.7 and 1.5 × 10 6 cells/ml) and culture volumes (20, 70 and 210 ml). At algae densities ranging from 0.3 to 1.5 × 10 6 cells/ml, an average μ value of more than 0.90 per day were recorded for all algae species. However, at density of 0.1 × 10 6 cells/ml, only Tetraselmis sp. resulted in the significantly highest μ value compared with others ( p < 0.05). In terms of volume, smaller culture volume of Tetraselmis sp. (20 ml) showed significantly higher μ compared with higher volume (70 and 210 ml cultures).

Measuring N2 Pressure Using Cyanobacteria Discipline: Geomicrobiology

NASA Technical Reports Server (NTRS)

Silverman, Shaelyn N.; Kopf, Sebastian; Gordon, Richard; Bebout, Brad M.; Som, Sanjoy

2017-01-01

The evolution of Earth's atmosphere has been governed by biological evolution. Dinitrogen (N2) has been a major constituent of Earth's atmosphere throughout the planet's history, yet only a few constraints exist for the partial pressure of N2 (pN2). In this study we evaluate two new potential proxies for pN2: the physical spacing between heterocysts and the isotopic signature of nitrogen fixation in filamentous cyanobacteria. Heterocyst-forming filamentous cyanobacteria are some of the oldest photosynthetic microorganisms on Earth, and debated fossilized specimens have been found in sedimentary rocks as old as 2 Ga. These organisms overcome nitrogen limitation in their aqueous environment through cellular differentiation along their filaments. The specialized cells that develop, known as heterocysts, fix the nitrogen and laterally distribute it to neighboring cells along the filaments. Because the concentration of the dissolved N2 available to the filaments correlates directly with pN2, any preservable physiological response of the organism to the changed N2 availability constitutes a potential proxy for pN2. In the laboratory, we have examined how pN2 is reflected in the heterocyst spacing pattern and in the isotopic signature of nitrogen fixation by subjecting the representative species Anabaena cylindrica and Anabaena variabilis to different N2 partial pressures during growth at constant temperature and lighting (in media free of combined nitrogen). We show experimentally that the distance between heterocysts and the nitrogen isotope fractionation measured in bulk biomass reflect the pN2 experienced by Anabaena cylindrica. Current work is investigating these responses in Anabaena variabilis. When heterocystous cyanobacteria fossilize, these morphological and isotopic signatures should preserve information about pN2 at that time. Application of this relationship to the rock record may provide a paleoproxy to complement the two existing geobarometers.

Induction of Larval Settlement in the Reef Coral Porites astreoides by a Cultivated Marine Roseobacter Strain.

PubMed

Sharp, K H; Sneed, J M; Ritchie, K B; Mcdaniel, L; Paul, V J

2015-04-01

Successful larval settlement and recruitment by corals is critical for the survival of coral reef ecosystems. Several closely related strains of γ-proteobacteria have been identified as cues for coral larval settlement, but the inductive properties of other bacterial taxa naturally occurring in reef ecosystems have not yet been explored. In this study, we assayed bacterial strains representing taxonomic groups consistently detected in corals for their ability to influence larval settlement in the coral Porites astreoides. We identified one α-proteobacterial strain, Roseivivax sp. 46E8, which significantly increased larval settlement in P. astreoides. Logarithmic growth phase (log phase) cell cultures of Roseivivax sp. 46E8 and filtrates (0.22μm) from log phase Roseivivax sp. 46E8 cultures significantly increased settlement, suggesting that an extracellular settlement factor is produced during active growth phase. Filtrates from log phase cultures of two other bacterial isolates, Marinobacter sp. 46E3, and Cytophaga sp. 46B6, also significantly increased settlement, but the cell cultures themselves did not. Monospecific biofilms of the three strains did not result in significant increases in larval settlement. Organic and aqueous/methanol extracts of Roseivivax sp. 46E8 cultures did not affect larval settlement. Examination of filtrates from cell cultures showed that Roseivivax sp. 46E8 spontaneously generated virus-like particles in log and stationary phase growth. Though the mechanism of settlement enhancement by Roseivivax sp. 46E8 is not yet elucidated, our findings point to a new aspect of coral-Roseobacter interactions that should be further investigated, especially in naturally occurring, complex microbial biofilms on reef surfaces. © 2015 Marine Biological Laboratory.

Growth of Chlamydomonas reinhardtii in acetate-free medium when co-cultured with alginate-encapsulated, acetate-producing strains of Synechococcus sp. PCC 7002.

PubMed

Therien, Jesse B; Zadvornyy, Oleg A; Posewitz, Matthew C; Bryant, Donald A; Peters, John W

2014-01-01

The model alga Chlamydomonas reinhardtii requires acetate as a co-substrate for optimal production of lipids, and the addition of acetate to culture media has practical and economic implications for algal biofuel production. Here we demonstrate the growth of C. reinhardtii on acetate provided by mutant strains of the cyanobacterium Synechococcus sp. PCC 7002. Optimal growth conditions for co-cultivation of C. reinhardtii with wild-type and mutant strains of Synechococcus sp. 7002 were established. In co-culture, acetate produced by a glycogen synthase knockout mutant of Synechococcus sp. PCC 7002 was able to support the growth of a lipid-accumulating mutant strain of C. reinhardtii defective in starch production. Encapsulation of Synechococcus sp. PCC 7002 using an alginate matrix was successfully employed in co-cultures to limit growth and maintain the stability. The ability of immobilized strains of the cyanobacterium Synechococcus sp. PCC 7002 to produce acetate at a level adequate to support the growth of lipid-accumulating strains of C. reinhartdii offers a potentially practical, photosynthetic alternative to providing exogenous acetate into growth media.

Mycosporine-like amino acids (MAAs) profile of a rice-field cyanobacterium Anabaena doliolum as influenced by PAR and UVR.

PubMed

Singh, Shailendra P; Sinha, Rajeshwar P; Klisch, Manfred; Häder, Donat-P

2008-12-01

The mycosporine-like amino acid (MAA) profile of a rice-field cyanobacterium, Anabaena doliolum, was studied under PAR and PAR + UVR conditions. The high-performance liquid chromatographic analysis of water-soluble compounds reveals the biosynthesis of three MAAs, mycosporine-glycine (lambda (max) = 310 nm), porphyra-334 (lambda (max) = 334 nm) and shinorine (lambda (max) = 334 nm), with retention times of 4.1, 3.5 and 2.3 min, respectively. This is the first report for the occurrence of mycosporine-glycine and porphyra-334 in addition to shinorine in Anabaena strains studied so far. The results indicate that mycosporine-glycine (monosubstituted) acts as a precursor for the biosynthesis of the bisubstituted MAAs shinorine and porphyra-334. Mycosporine-glycine was under constitutive control while porphyra-334 and shinorine were induced by UV-B radiation, indicating the involvement of UV-regulated enzymes in the biotransformation of MAAs. It seems that A. doliolum is able to protect its cell machinery from UVR by synthesizing a complex set of MAAs and thus is able to survive successfully during the summer in its natural brightly lit habitats.

Effects of lead accumulation on the Azolla caroliniana-Anabaena association.

PubMed

Roberts, Anne E; Boylen, Charles W; Nierzwicki-Bauer, Sandra A

2014-04-01

The effect of lead accumulation on photopigment production, mineral nutrition, and Anabaena vegetative cell size and heterocyst formation in Azolla caroliniana was investigated. Plants were exposed to 0, 1, 5, 10, and 20 mg L(-1) lead acetate for ten days. Lead accumulation increased when plants were treated with higher lead concentrations. Results revealed a statistically significant decline in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoids in 5, 10, and 20 mg Pb L(-1) treatment groups as compared to plants with 0 or 1 mg Pb L(-1) treatments. No statistically significant change in anthocyanin production was observed. Calcium, magnesium, and zinc concentrations in plants decreased in increasing treatment groups, whereas sodium and potassium concentrations increased. Nitrogen and carbon were also found to decrease in plant tissue. Anabaena vegetative cells decreased in size and heterocyst frequency declined rapidly in a Pb dose-dependent manner. These results indicate that, while A. caroliniana removes lead from aqueous solution, the heavy metal causes physiological and biochemical changes by impairing photosynthesis, changing mineral nutrition, and impeding the growth and formation of heterocysts of the symbiotic cyanobacteria that live within leaf cavities of the fronds. Copyright © 2014. Published by Elsevier Inc.

Diversity of endophytic fungi associated with the foliar tissue of a hemi-parasitic plant Macrosolen cochinchinensis.

PubMed

Zhou, Sheng-Liang; Yan, Shu-Zhen; Liu, Qi-Sha; Chen, Shuang-Lin

2015-01-01

Foliar fungal endophytes are an important plant-associated fungal group. However, little is known about these fungi in hemi-parasitic plants, a unique plant group which derive nutrients from living plants of its hosts by haustoria while are photosynthetic to some degree. In this paper, the endophytic fungi in the leaves of a species of hemi-parasitic plant, Macrosolen cochinchinensis, were studied by both culture-dependent and culture-independent methods. By culture-dependent method, a total of 511 isolates were recovered from 452 of 600 leaf fragments (colonization rate = 75.3 %) and were identified to be 51 taxa. Valsa sp. was the most abundant (relative abundance = 38.4 %), followed by Cladosporium sp. 1 (13.5 %), Ulocladium sp. (4.3 %), Phomopsis sp. 2 (3.7 %), Hendersonia sp. (3.5 %), and Diaporthe sp. 4 (3.5 %). The Shannon index (H') of the isolated endophytic fungi was 2.628, indicating a moderate diversity. By culture-independent method, Aspergillus spp., Cladosporium sp., Mycosphaerella sp., Acremonium strictum, and Tremella sp. were detected. To our knowledge, the Tremella species have never been detected as endophytes so far. In addition, a cloned sequence was not similar with any current sequence in the Genbank, which may represent a novel species. Altogether, this study documented endophytic fungal assemble in the leaves of M. cochinchinensis which was worthy of our attention, and may expand our knowledge about endophytic fungi within the photosynthetic tissues of plants.

To bloom or not to bloom: contrasting responses of cyanobacteria to recent heat waves explained by critical thresholds of abiotic drivers.

PubMed

Huber, Veronika; Wagner, Carola; Gerten, Dieter; Adrian, Rita

2012-05-01

Past heat waves are considered harbingers of future climate change. In this study, we have evaluated the effects of two recent Central European summer heat waves (2003 and 2006) on cyanobacterial blooms in a eutrophic, shallow lake. While a bloom of cyanobacteria developed in 2006, consistent with our expectations, cyanobacterial biomass surprisingly remained at a record-low during the entire summer of 2003. Critical thresholds of abiotic drivers extracted from the long-term (1993-2007) data set of the studied lake using classification tree analysis (CTA) proved suitable to explain these observations. We found that cyanobacterial blooms were especially favoured in 2006 because thermal stratification was critically intense (Schmidt stability >44 g cm cm(-2)) and long-lasting (>3 weeks). Our results also suggest that some cyanobacterial species (Anabaena sp.) benefitted directly from the stable water column, whereas other species (Planktothrix sp.) took advantage of stratification-induced internal nutrient loading. In 2003, conditions were less favourable for cyanobacteria due to a spell of lower temperatures and stronger winds in mid-summer; as a result, the identified thresholds of thermal stratification were hardly ever reached. Overall, our study shows that extracting critical thresholds of environmental drivers from long-term records is a promising avenue for predicting ecosystem responses to future climate warming. Specifically, our results emphasize that not average temperature increase but changes in short-term meteorological variability will determine whether cyanobacteria will bloom more often in a warmer world.

Evaluation of an On-Farm Culture System (Accumast) for Fast Identification of Milk Pathogens Associated with Clinical Mastitis in Dairy Cows.

PubMed

Ganda, Erika Korzune; Bisinotto, Rafael Sisconeto; Decter, Dean Harrison; Bicalho, Rodrigo Carvalho

2016-01-01

The present study aimed evaluate an on-farm culture system for identification of milk pathogens associated with clinical mastitis in dairy cows using two different gold standard approaches: standard laboratory culture in study 1 and 16S rRNA sequencing in study 2. In study 1, milk from mastitic quarters (i.e. presence of flakes, clots, or serous milk; n = 538) was cultured on-farm using a single plate containing three selective chromogenic media (Accumast-FERA Animal Health LCC, Ithaca, NY) and in a reference laboratory using standard culture methods, which was considered the gold standard. In study 2, mastitic milk was cultured on-farm and analyzed through 16S rRNA sequencing (n = 214). In both studies, plates were cultured aerobically at 37°C for 24 h and read by a single technician masked to gold standard results. Accuracy, sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were calculated based on standard laboratory culture in study 1, and PPV was calculated based on sequencing results in study 2. Overall accuracy of Accumast was 84.9%. Likewise, accuracy for identification of Gram-negative bacteria, Staphylococcus sp., and Streptococcus sp. was 96.4%, 93.8%, and 91.5%, respectively. Sensitivity, specificity, PPV, and NPV were 75.0%, 97.9%, 79.6%, and 97.3% for identification of E. coli, 100.0%, 99.8%, 87.5%, and 100.0% for S. aureus, 70.0%, 95.0%, 45.7%, and 98.1% for other Staphylococcus sp., and 90.0%, 92.9%, 91.8%, and 91.2% for Streptococcus sp. In study 2, Accumast PPV was 96.7% for E. coli, 100.0% for Enterococcus sp., 100.0% for Other Gram-negatives, 88.2% for Staphylococcus sp., and 95.0% for Streptococcus sp., respectively. In conclusion, Accumast is a unique approach for on-farm identification pathogens associated with mastitis, presenting overall sensitivity and specificity of 82.3% and 89.9% respectively.

Evaluation of an On-Farm Culture System (Accumast) for Fast Identification of Milk Pathogens Associated with Clinical Mastitis in Dairy Cows

PubMed Central

Ganda, Erika Korzune; Bisinotto, Rafael Sisconeto; Decter, Dean Harrison; Bicalho, Rodrigo Carvalho

2016-01-01

The present study aimed evaluate an on-farm culture system for identification of milk pathogens associated with clinical mastitis in dairy cows using two different gold standard approaches: standard laboratory culture in study 1 and 16S rRNA sequencing in study 2. In study 1, milk from mastitic quarters (i.e. presence of flakes, clots, or serous milk; n = 538) was cultured on-farm using a single plate containing three selective chromogenic media (Accumast—FERA Animal Health LCC, Ithaca, NY) and in a reference laboratory using standard culture methods, which was considered the gold standard. In study 2, mastitic milk was cultured on-farm and analyzed through 16S rRNA sequencing (n = 214). In both studies, plates were cultured aerobically at 37°C for 24 h and read by a single technician masked to gold standard results. Accuracy, sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were calculated based on standard laboratory culture in study 1, and PPV was calculated based on sequencing results in study 2. Overall accuracy of Accumast was 84.9%. Likewise, accuracy for identification of Gram-negative bacteria, Staphylococcus sp., and Streptococcus sp. was 96.4%, 93.8%, and 91.5%, respectively. Sensitivity, specificity, PPV, and NPV were 75.0%, 97.9%, 79.6%, and 97.3% for identification of E. coli, 100.0%, 99.8%, 87.5%, and 100.0% for S. aureus, 70.0%, 95.0%, 45.7%, and 98.1% for other Staphylococcus sp., and 90.0%, 92.9%, 91.8%, and 91.2% for Streptococcus sp. In study 2, Accumast PPV was 96.7% for E. coli, 100.0% for Enterococcus sp., 100.0% for Other Gram-negatives, 88.2% for Staphylococcus sp., and 95.0% for Streptococcus sp., respectively. In conclusion, Accumast is a unique approach for on-farm identification pathogens associated with mastitis, presenting overall sensitivity and specificity of 82.3% and 89.9% respectively. PMID:27176216

A synthetic oligopeptide derived from enamel matrix derivative promotes the differentiation of human periodontal ligament stem cells into osteoblast-like cells with increased mineralization.

PubMed

Kato, Hirohito; Katayama, Nobuhito; Taguchi, Yoichiro; Tominaga, Kazuya; Umeda, Makoto; Tanaka, Akio

2013-10-01

In a previous study, the authors obtained a synthetic peptide (SP) for useful periodontal tissue regeneration. Periodontal ligament stem cells (PDLSCs) have multiple potentiality to contribute to tissue regeneration. The aim of this experiment is to investigate the effect of SP on human PDLSCs. Periodontal ligament cells were obtained from healthy adult human third molars and used to isolate single PDLSC-derived colonies. The mesenchymal stem cell nature of the PDLSCs was confirmed by immunohistochemical evaluation of STRO-1 expression. Proliferation and osteoblastic differentiation were investigated by culturing PDLSCs in normal or osteogenic medium with and without SP (100 ng/mL). Osteoblast differentiation was assessed by measuring alkaline phosphatase (ALP) activity, osteocalcin production, mRNA expression of osteonectin, mineralization, and calcium deposition. Isolated PDLSCs were immunohistochemically positive for vimentin and STRO-1 and negative for cytokeratin. A greater number of calcified nodules were observed in osteogenic medium culture with SP than without. In the early and later stages of PDLSC culture with SP, osteonectin production and osteocalcin production were increased. SP in culture with osteogenic medium significantly enhanced proliferation of PDLSCs, as well as ALP activity, expression of osteonectin, osteocalcin production, formation of calcified nodules, and mineralization. SP enhances the formation of calcified nodules and osteocalcin production in the culture of PDLSCs into osteoblast-like cells and is a useful material for periodontal tissue regeneration.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chaurasia, Neha; Mishra, Yogesh; Rai, Lal Chand

Phytochelatin synthase (PCS) is involved in the synthesis of phytochelatins (PCs), plays role in heavy metal detoxification. The present study describes for first time the functional expression and characterization of pcs gene of Anabaena sp. PCC 7120 in Escherichia coli in terms of offering protection against heat, salt, carbofuron (pesticide), cadmium, copper, and UV-B stress. The involvement of pcs gene in tolerance to above abiotic stresses was investigated by cloning of pcs gene in expression vector pGEX-5X-2 and its transformation in E. coli BL21 (DE3). The E. coli cells transformed with pGEX-5X-pcs showed better growth than control cells (pGEX-5X-2) undermore » temperature (47 deg. C), NaCl (6% w/v), carbofuron (0.025 mg ml{sup -1}), CdCl{sub 2} (4 mM), CuCl{sub 2} (1 mM), and UV-B (10 min) exposure. The enhanced expression of pcs gene revealed by RT-PCR analysis under above stresses at different time intervals further advocates its role in tolerance against above abiotic stresses.« less

Direct analysis of phycobilisomal antenna proteins and metabolites in small cyanobacterial populations by laser ablation electrospray ionization mass spectrometry.

PubMed

Parsiegla, Goetz; Shrestha, Bindesh; Carrière, Frédéric; Vertes, Akos

2012-01-03

Due to their significance in energy and environmental and natural product research, as well as their large genetic diversity, rapid in situ analysis of cyanobacteria is of increasing interest. Metabolic profiles and the composition of energy harvesting antenna protein complexes are needed to understand how environmental factors affect the functioning of these microorganisms. Here, we show that laser ablation electrospray ionization (LAESI) mass spectrometry enables the direct analysis of phycobilisomal antenna proteins and report on numerous metabolites from intact cyanobacteria. Small populations (n < 616 ± 76) of vegetative Anabaena sp. PCC7120 cyanobacterial cells are analyzed by LAESI mass spectrometry. The spectra reveal the ratio of phycocyanin (C-PC) and allophycocyanin (APC) in the antenna complex, the subunit composition of the phycobiliproteins, and the tentative identity of over 30 metabolites and lipids. Metabolites are tentatively identified by accurate mass measurements, isotope distribution patterns, and literature searches. The rapid simultaneous analysis of abundant proteins and diverse metabolites enables the evaluation of the environmental response and metabolic adaptation of cyanobacteria and other microorganisms. © 2011 American Chemical Society

Development of a process for efficient use of CO2 from flue gases in the production of photosynthetic microorganisms.

PubMed

González-López, C V; Acién Fernández, F G; Fernández-Sevilla, J M; Sánchez Fernández, J F; Molina Grima, E

2012-07-01

A new methodology to use efficiently flue gases as CO(2) source in the production of photosynthetic microorganisms is proposed. The CO(2) is absorbed in an aqueous phase that is then regenerated by microalgae. Carbonated solutions could absorb up to 80% of the CO(2) from diluted gas reaching total inorganic carbon (TIC) concentrations up to 2.0 g/L. The pH of the solution was maintained at 8.0-10.0 by the bicarbonate/carbonate buffer, so it is compatible with biological regeneration. The absorption process was modeled and the kinetic parameters were determined. Anabaena sp. demonstrated to tolerate pH (8.0-10.0) and TIC (up to 2.0 g/L) conditions imposed by the absorption step. Experiments of regeneration of the liquid phase demonstrated the feasibility of the overall process, converting CO(2) into organic matter. The developed process avoids heating to regenerate the liquid whereas maximizing the efficiency of CO(2) use, which is relevant to achieve the commercial production of biofuels from microalgae. Copyright © 2012 Wiley Periodicals, Inc.

Phycobilisomes from blue-green and red algae: isolation criteria and dissociation characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gantt, E.; Lipschultz, C.A.; Grabowski, J.

1979-04-01

A general procedure for the isolation of functionally intact phycobilisomes was devised, based on modifications of previously used procedures. It has been successful with numerous species of red and blue-green algae (Anabaena variabilis, Anacystis nidulans, Agmenellum quadruplicatum, Fremyella diplosiphon, Glaucosphaera vacuolata, Griffithsia pacifica, Nemalion multifidum, Nostoc sp., Phormidium persicinum, Porphyridium cruentum, P. sordidum, P. aerugineum, Rhodosorus marinus). Isolation was carried out in 0.75 molar K-phosphate (pH 6.8 to 7.0) at 20 to 23 C on sucrose step gradients. Lower temperature (4 to 10 C) was usually unfavorable resulting in uncoupling of energy transfer and partial dissociation of the phycobilisomes, sometimesmore » with complete loss of allophycocyanin. Intact phycobilisomes were characterized by fluorescence emission peaks of 670 to 675 nanometers at room temperature, and 678 to 685 nanometers at liquid nitrogen temperature. Uncoupling and subsequent dissociation of phycobilisomes, in lowered ionic conditions, varied with the species and the degree of dissociation but occurred preferentially between phycocyanin and allophycocyanin, or between phycocyanin and phycoerythrin.« less

Identification of toxigenic Cyanobacteria of the genus Microcystis in the Curonian Lagoon (Baltic Sea)

NASA Astrophysics Data System (ADS)

Belykh, O. I.; Dmitrieva, O. A.; Gladkikh, A. S.; Sorokovikova, E. G.

2013-02-01

In 2002-2008, seasonal (April-November) monitoring of the phytoplankton in the Russian part of the Curonian Lagoon at five fixed sites was performed. A total of 91 Cyanobacteria, 100 Bacillariophyta, 280 Chlorophyta, 21 Cryptophyta, and 24 Dinophyta species were found. Six potentially toxic species of cyanobacteria: Aphanizomenon flos-aquae, Anabaena sp., Microcystis aeruginosa, M. viridis, M. wesenbergii, and Planktothrix agardhii dominated the phytoplankton biomass and caused water blooms. The seasonal average phytoplankton biomass ranged from 30 to 137 g/m3. The cyanobacteria's biomass varied from 10 to 113 g/m3 forming 30-82% of the total with a mean of 50%. With the aid of genetic markers (microcystin ( mcy) and nodularin synthetases), six variants of the microcystin-producing gene mcyE from the genus Microcystis were identified. Due to the intensive and lengthy blooms of potentially toxic and toxigenic cyanobacteria, the environmental conditions in the Curonian Lagoon appear unfavorable. The water should be monitored for cyanotoxins with analytical methods in order to determine if the area is safe for recreational use.

Isolation and screening of heterocystous cyanobacterial strains for biodiesel production by evaluating the fuel properties from fatty acid methyl ester (FAME) profiles.

PubMed

Anahas, Antonyraj Matharasi Perianaika; Muralitharan, Gangatharan

2015-05-01

This study reports on the biodiesel quality parameters of eleven heterocystous cyanobacterial strains based on fatty acid methyl esters (FAME) profiles. The biomass productivity of the tested cyanobacterial strains ranged from 9.33 to 20.67 mg L(-1) d(-1) while the lipid productivity varied between 0.65 and 2.358 mg L(-1) d(-1). The highest biomass and lipid productivity was observed for Calothrix sp. MBDU 013 but its lipid content is only 11.221 in terms of percent dry weight, next to the Anabaena sphaerica MBDU 105, whose lipid content is high. To identify the most competent isolate, a multi-criteria decision analyses (MCDA) was performed by including the key chemical and physical parameters of biodiesel calculated from FAME profiles. The isolate A.sphaerica MBDU 105 is the most promising biodiesel feed stock based on decision vector through Preference Ranking Organisation Method for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GAIA) analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Removal of phenanthrene from soil by co-cultures of bacteria and fungi pregrown on sugarcane bagasse pith.

PubMed

Chávez-Gómez, B; Quintero, R; Esparza-García, F; Mesta-Howard, A M; Zavala Díaz de la Serna, F J; Hernández-Rodríguez, C H; Gillén, T; Poggi-Varaldo, H M; Barrera-Cortés, J; Rodríguez-Vázquez, R

2003-09-01

Sixteen co-cultures composed of four bacteria and four fungi grown on sugarcane bagasse pith were tested for phenanthrene degradation in soil. The four bacteria were identified as Pseudomonas aeruginose, Ralstonia pickettii, Pseudomonas sp. and Pseudomonas cepacea. The four fungi were identified as: Penicillium sp., Trichoderma viride, Alternaria tenuis and Aspergillus terrus that were previously isolated from different hydrocarbon-contaminated soils. Fungi had a statistically significant positive (0.0001

Utilization of LPG and gasoline engine exhaust emissions by microalgae.

PubMed

Taştan, Burcu Ertit; Duygu, Ergin; Ilbaş, Mustafa; Dönmez, Gönül

2013-02-15

The effect of engine exhaust emissions on air pollution is one of the greatest problems that the world is facing today. The study focused on the effects of realistic levels of engine exhaust emissions of liquid petroleum gas (LPG) and gasoline (GSN) on Phormidium sp. and Chlorella sp. Multi parameters including pH, different medial compositions, fuel types, flow rates and biomass concentrations were described in detail. Effects of some growth factors such as triacontanol (TRIA) and salicylic acid (SA) have also been tested. The maximum biomass concentration of Phormidium sp. reached after 15 days at 0.36 and 0.15 g/L initial biomass concentrations were found as 1.160 g/L for LPG emission treated cultures and 1.331 g/L for GSN emission treated cultures, respectively. The corresponding figures were 1.478 g/L for LPG emission treated cultures and 1.636 g/L for GSN emission treated cultures at 0.65 and 0.36 g/L initial Chlorella sp. biomass concentrations. This study highlights the significance of using Phormidium sp. and Chlorella sp. for utilization of LPG and GSN engine exhaust emissions by the help of growth factors. Copyright © 2013. Published by Elsevier B.V.

Microalgal biomass production and on-site bioremediation of carbon dioxide, nitrogen oxide and sulfur dioxide from flue gas using Chlorella sp. cultures.

PubMed

Chiu, Sheng-Yi; Kao, Chien-Ya; Huang, Tzu-Ting; Lin, Chia-Jung; Ong, Seow-Chin; Chen, Chun-Da; Chang, Jo-Shu; Lin, Chih-Sheng

2011-10-01

The growth and on-site bioremediation potential of an isolated thermal- and CO₂-tolerant mutant strain, Chlorella sp. MTF-7, were investigated. The Chlorella sp. MTF-7 cultures were directly aerated with the flue gas generated from coke oven of a steel plant. The biomass concentration, growth rate and lipid content of Chlorella sp. MTF-7 cultured in an outdoor 50-L photobioreactor for 6 days was 2.87 g L⁻¹ (with an initial culture biomass concentration of 0.75 g L⁻¹), 0.52 g L⁻¹ d⁻¹ and 25.2%, respectively. By the operation with intermittent flue gas aeration in a double-set photobioreactor system, average efficiency of CO₂ removal from the flue gas could reach to 60%, and NO and SO₂ removal efficiency was maintained at approximately 70% and 50%, respectively. Our results demonstrate that flue gas from coke oven could be directly introduced into Chlorella sp. MTF-7 cultures to potentially produce algal biomass and efficiently capture CO₂, NO and SO₂ from flue gas. Copyright © 2011 Elsevier Ltd. All rights reserved.

Phylogenetic Analysis and Antimicrobial Profiles of Cultured Emerging Opportunistic Pathogens (Phyla Actinobacteria and Proteobacteria) Identified in Hot Springs.

PubMed

Jardine, Jocelyn Leonie; Abia, Akebe Luther King; Mavumengwana, Vuyo; Ubomba-Jaswa, Eunice

2017-09-15

Hot spring water may harbour emerging waterborne opportunistic pathogens that can cause infections in humans. We have investigated the diversity and antimicrobial resistance of culturable emerging and opportunistic bacterial pathogens, in water and sediment of hot springs located in Limpopo, South Africa. Aerobic bacteria were cultured and identified using 16S ribosomal DNA (rDNA) gene sequencing. The presence of Legionella spp. was investigated using real-time polymerase chain reaction. Isolates were tested for resistance to ten antibiotics representing six different classes: β-lactam (carbenicillin), aminoglycosides (gentamycin, kanamycin, streptomycin), tetracycline, amphenicols (chloramphenicol, ceftriaxone), sulphonamides (co-trimoxazole) and quinolones (nalidixic acid, norfloxacin). Gram-positive Kocuria sp. and Arthrobacter sp. and gram-negative Cupriavidus sp., Ralstonia sp., Cronobacter sp., Tepidimonas sp., Hafnia sp. and Sphingomonas sp. were isolated, all recognised as emerging food-borne pathogens. Legionella spp. was not detected throughout the study. Isolates of Kocuria , Arthrobacter and Hafnia and an unknown species of the class Gammaproteobacteria were resistant to two antibiotics in different combinations of carbenicillin, ceftriaxone, nalidixic acid and chloramphenicol. Cronobacter sp. was sensitive to all ten antibiotics. This study suggests that hot springs are potential reservoirs for emerging opportunistic pathogens, including multiple antibiotic resistant strains, and highlights the presence of unknown populations of emerging and potential waterborne opportunistic pathogens in the environment.

Efficient Secretion of Recombinant Proteins from Rice Suspension-Cultured Cells Modulated by the Choice of Signal Peptide.

PubMed

Huang, Li-Fen; Tan, Chia-Chun; Yeh, Ju-Fang; Liu, Hsin-Yi; Liu, Yu-Kuo; Ho, Shin-Lon; Lu, Chung-An

2015-01-01

Plant-based expression systems have emerged as a competitive platform in the large-scale production of recombinant proteins. By adding a signal peptide, αAmy3sp, the desired recombinant proteins can be secreted outside transgenic rice cells, making them easy to harvest. In this work, to improve the secretion efficiency of recombinant proteins in rice expression systems, various signal peptides including αAmy3sp, CIN1sp, and 33KDsp have been fused to the N-terminus of green fluorescent protein (GFP) and introduced into rice cells to explore the efficiency of secretion of foreign proteins. 33KDsp had better efficiency than αAmy3sp and CIN1sp for the secretion of GFP from calli and suspension-cultured cells. 33KDsp was further applied for the secretion of mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) from transgenic rice suspension-cultured cells; approximately 76%-92% of total rice-derived mGM-CSF (rmGM-CSF) was detected in the culture medium. The rmGM-CSF was bioactive and could stimulate the proliferation of a murine myeloblastic leukemia cell line, NSF-60. The extracellular yield of rmGM-CSF reached 31.7 mg/L. Our study indicates that 33KDsp is better at promoting the secretion of recombinant proteins in rice suspension-cultured cell systems than the commonly used αAmy3sp.

Sleep Paralysis in Brazilian Folklore and Other Cultures: A Brief Review

PubMed Central

de Sá, José F. R.; Mota-Rolim, Sérgio A.

2016-01-01

Sleep paralysis (SP) is a dissociative state that occurs mainly during awakening. SP is characterized by altered motor, perceptual, emotional and cognitive functions, such as inability to perform voluntary movements, visual hallucinations, feelings of chest pressure, delusions about a frightening presence and, in some cases, fear of impending death. Most people experience SP rarely, but typically when sleeping in supine position; however, SP is considered a disease (parasomnia) when recurrent and/or associated to emotional burden. Interestingly, throughout human history, different peoples interpreted SP under a supernatural view. For example, Canadian Eskimos attribute SP to spells of shamans, who hinder the ability to move, and provoke hallucinations of a shapeless presence. In the Japanese tradition, SP is due to a vengeful spirit who suffocates his enemies while sleeping. In Nigerian culture, a female demon attacks during dreaming and provokes paralysis. A modern manifestation of SP is the report of “alien abductions”, experienced as inability to move during awakening associated with visual hallucinations of aliens. In all, SP is a significant example of how a specific biological phenomenon can be interpreted and shaped by different cultural contexts. In order to further explore the ethnopsychology of SP, in this review we present the “Pisadeira”, a character of Brazilian folklore originated in the country’s Southeast, but also found in other regions with variant names. Pisadeira is described as a crone with long fingernails who lurks on roofs at night and tramples on the chest of those who sleep on a full stomach with the belly up. This legend is mentioned in many anthropological accounts; however, we found no comprehensive reference on the Pisadeira from the perspective of sleep science. Here, we aim to fill this gap. We first review the neuropsychological aspects of SP, and then present the folk tale of the Pisadeira. Finally, we summarize the many historical and artistic manifestations of SP in different cultures, emphasizing the similarities and differences with the Pisadeira. PMID:27656151

Vibrio sp. DSM 14379 pigment production--a competitive advantage in the environment?

PubMed

Starič, Nejc; Danevčič, Tjaša; Stopar, David

2010-10-01

The ability to produce several antibacterial agents greatly increases the chance of producer's survival. In this study, red-pigmented Vibrio sp. DSM 14379 and Bacillus sp., both isolated from the same sampling volume from estuarine waters of the Northern Adriatic Sea, were grown in a co-culture. The antibacterial activity of the red pigment extract was tested on Bacillus sp. in microtiter plates. The MIC(50) for Bacillus sp. was estimated to be around 10⁻⁵ mg/L. The extract prepared form the nonpigmented mutant of Vibrio sp. had no antibacterial effect. The pigment production of Vibrio sp. was studied under different physicochemical conditions. There was no pigment production at high or low temperatures, high or low salt concentrations in peptone yeast extract (PYE) medium, low glucose concentration in mineral growth medium or high glucose concentration in PYE medium. This indicates that the red pigment production is a luxurious good that Vibrio sp. makes only under favorable conditions. The Malthusian fitness of Bacillus sp. in a co-culture with Vibrio sp. under optimal environmental conditions dropped from 4.0 to -7.6, which corresponds to three orders of magnitude decrease in the number of CFU relative to the monoculture. The nonpigmented mutant of Vibrio sp. in a co-culture with Bacillus sp. had a significant antibacterial activity. This result shows that studying antibacterial properties in isolation (i.e. pigment extract only) may not reveal full antibacterial potential of the bacterial strain. The red pigment is a redundant antibacterial agent of Vibrio sp.

Alveolar type II cell-fibroblast interactions, synthesis and secretion of surfactant and type I collagen.

PubMed

Griffin, M; Bhandari, R; Hamilton, G; Chan, Y C; Powell, J T

1993-06-01

During alveolar development and alveolar repair close contacts are established between fibroblasts and lung epithelial cells through gaps in the basement membrane. Using co-culture systems we have investigated whether these close contacts influence synthesis and secretion of the principal surfactant apoprotein (SP-A) by cultured rat lung alveolar type II cells and the synthesis and secretion of type I collagen by fibroblasts. The alveolar type II cells remained cuboidal and grew in colonies on fibroblast feeder layers and on Matrigel-coated cell culture inserts but were progressively more flattened on fixed fibroblast monolayers and plastic. Alveolar type II cells cultured on plastic released almost all their SP-A into the medium by 4 days. Alveolar type II cells cultured on viable fibroblasts or Matrigel-coated inserts above fibroblasts accumulated SP-A in the medium at a constant rate for the first 4 days, and probably recycle SP-A by endocytosis. The amount of mRNA for SP-A was very low after 4 days of culture of alveolar type II cells on plastic, Matrigel-coated inserts or fixed fibroblast monolayers: relatively, the amount of mRNA for SP-A was increased 4-fold after culture of alveolar type II cells on viable fibroblasts. Co-culture of alveolar type II cells with confluent human dermal fibroblasts stimulated by 2- to 3-fold the secretion of collagen type I into the culture medium, even after the fibroblasts' growth had been arrested with mitomycin C. Collagen secretion, by fibroblasts, also was stimulated 2-fold by conditioned medium from alveolar type II cells cultured on Matrigel. The amount of mRNA for type I collagen increased only modestly when fibroblasts were cultured in this conditioned medium. This stimulation of type I collagen secretion diminished as the conditioned medium was diluted out, but at high dilutions further stimulation occurred, indicating that a factor that inhibited collagen secretion also was being diluted out. The conditioned medium contained low levels of IGF-1 and the stimulation of type I collagen secretion was abolished when the conditioned medium was pre-incubated with antibodies to insulin-like growth factor 1 (IGF-1). There are important reciprocal interactions between alveolar type II cells and fibroblasts in co-culture. Direct contacts between alveolar type II cells and fibroblasts appear to have a trophic effect on cultured alveolar type II cells, increasing the levels of mRNA for SP-A. Rat lung alveolar type II cells appear to release a factor (possibly IGF-1) that stimulates type I collagen secretion by fibroblasts.

[Correlation between clinical characteristics and mycological tests in the vulvovaginitis by Candida].

PubMed

Buitrón García, Rafael; Bonifaz, Alexandro; Amancio Chassin, Octavio; Basurto Kuba, Erich; Araiza, Javier; Romero Cabello, Raúl

2007-02-01

Vulvovaginitis caused by Candida sp is one of the most frequent infections. To culture and to identify the fungi related to clinical manifestations of patients based on a suspected diagnosis of vulvovaginal candidiasis. A prospective, transversal and comparative study was performed on 181 women older than 18 years with vulvovaginitis by Candida sp. A correlation was made between the clinical characteristics of this entity and mycological tests such as direct examination and cultures. The direct exam or fresh vaginal exam and cervical sample was positive for the different microscopic forms of Candida (blastoconidia, pseudohyphye or pseudomycelia) in 60.8% (110 women); at the same time that cultures were positive for Candida sp in 51.9% (94 patients). The direct examination and the cultures of vaginal and cervical exudate are mandatory tests for diagnosis of Candida sp in women with vulvovaginitis.

Cultivation of Chlorella sp. with livestock waste compost for lipid production.

PubMed

Zhu, L-D; Li, Z-H; Guo, D-B; Huang, F; Nugroho, Y; Xia, K

2017-01-01

Cultivation of microalgae Chlorella sp. with livestock waste compost as an alternative nutrient source was investigated in this present study. Five culture media with different nutrient concentrations were prepared. The characteristics of algal growth and lipid production were examined. The results showed that the specific growth rate together with biomass and lipid productivities was different among all the cultures. As the initial nutrient concentration decreased, the lipid content of Chlorella sp. increased. The variations in lipid productivity of Chlorella sp. among all the cultures were mainly due to the deviations in biomass productivity. The livestock waste compost medium with 2000mgL -1 COD provided an optimal nutrient concentration for Chlorella sp. cultivation, where the highest productivities of biomass (288.84mgL -1 day -1 ) and lipid (104.89mgL -1 day -1 ) were presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced biodegradation of alkane hydrocarbons and crude oil by mixed strains and bacterial community analysis.

PubMed

Chen, Yu; Li, Chen; Zhou, Zhengxi; Wen, Jianping; You, Xueyi; Mao, Youzhi; Lu, Chunzhe; Huo, Guangxin; Jia, Xiaoqiang

2014-04-01

In this study, two strains, Acinetobacter sp. XM-02 and Pseudomonas sp. XM-01, were isolated from soil samples polluted by crude oil at Bohai offshore. The former one could degrade alkane hydrocarbons (crude oil and diesel, 1:4 (v/v)) and crude oil efficiently; the latter one failed to grow on alkane hydrocarbons but could produce rhamnolipid (a biosurfactant) with glycerol as sole carbon source. Compared with pure culture, mixed culture of the two strains showed higher capability in degrading alkane hydrocarbons and crude oil of which degradation rate were increased from 89.35 and 74.32 ± 4.09 to 97.41 and 87.29 ± 2.41 %, respectively. In the mixed culture, Acinetobacter sp. XM-02 grew fast with sufficient carbon source and produced intermediates which were subsequently utilized for the growth of Pseudomonas sp. XM-01 and then, rhamnolipid was produced by Pseudomonas sp. XM-01. Till the end of the process, Acinetobacter sp. XM-02 was inhibited by the rapid growth of Pseudomonas sp. XM-01. In addition, alkane hydrocarbon degradation rate of the mixed culture increased by 8.06 to 97.41 % compared with 87.29 % of the pure culture. The surface tension of medium dropping from 73.2 × 10(-3) to 28.6 × 10(-3) N/m. Based on newly found cooperation between the degrader and the coworking strain, rational investigations and optimal strategies to alkane hydrocarbons biodegradation were utilized for enhancing crude oil biodegradation.

Relationship between the Unicellular Red Alga Porphyridium sp. and Its Predator, the Dinoflagellate Gymnodinium sp

PubMed Central

Ucko, Michal; Cohen, Ephraim; Gordin, Hillel; Arad, Shoshana (Malis)

1989-01-01

Contamination of algae cultivated outdoors by various microorganisms, such as bacteria, fungi, algae, and protozoa, can affect growth and product quality, sometimes causing fast collapse of the cultures. The main contaminant of Porphyridium cultures grown outdoors in Israel is a Gymnodinium sp., a dinoflagellate that feeds on the alga. Comparison of the effects of various environmental conditions, i.e., pH, salinity, and temperature, on Gymnodinium and Porphyridium species revealed that the Gymnodinium sp. has sharp optimum curves, whereas the Porphyridium sp. has a wider range of optimum conditions and is also more resistant to extreme environmental variables. The mode of preying on the alga was observed, and the specificity of the Gymnodinium sp. for the Porphyridium sp. was shown. In addition, Gymnodinium extract was shown to contain enzymatic degrading activity specific to the Porphyridium sp. cell wall polysaccharide. PMID:16348059

Carbon Monoxide, Hydrogen, and Formate Metabolism during Methanogenesis from Acetate by Thermophilic Cultures of Methanosarcina and Methanothrix Strains.

PubMed

Zinder, S H; Anguish, T

1992-10-01

CO and H(2) have been implicated in methanogenesis from acetate, but it is unclear whether they are directly involved in methanogenesis or electron transfer in acetotrophic methanogens. We compared metabolism of H(2), CO, and formate by cultures of the thermophilic acetotrophic methanogens Methanosarcina thermophila TM-1 and Methanothrix sp. strain CALS-1. M. thermophila accumulated H(2) to partial pressures of 40 to 70 Pa (1 Pa = 0.987 x 10 atm), as has been previously reported for this and other Methanosarcina cultures. In contrast, Methanothrix sp. strain CALS-1 accumulated H(2) to maximum partial pressures near 1 Pa. Growing cultures of Methanothrix sp. strain CALS-1 initially accumulated CO, which reached partial pressures near 0.6 Pa (some CO came from the rubber stopper) during the middle of methanogenesis; this was followed by a decrease in CO partial pressures to less than 0.01 Pa by the end of methanogenesis. Accumulation or consumption of CO by cultures of M. thermophila growing on acetate was not detected. Late-exponential-phase cultures of Methanothrix sp. strain CALS-1, in which the CO partial pressure was decreased by flushing with N(2)-CO(2), accumulated CO to 0.16 Pa, whereas cultures to which ca. 0.5 Pa of CO was added consumed CO until it reached this partial pressure. Cyanide (1 mM) blocked CO consumption but not production. High partial pressures of H(2) (40 kPa) inhibited methanogenesis from acetate by M. thermophila but not by Methanothrix sp. strain CALS-1, and 2 kPa of CO was not inhibitory to M. thermophila but was inhibitory to Methanothrix sp. strain CALS-1. Levels of CO dehydrogenase, hydrogenase, and formate dehydrogenase in Methanothrix sp. strain CALS-1 were 9.1, 0.045, and 5.8 mumol of viologen reduced min mg of protein. These results suggest that CO plays a role in Methanothrix sp. strain CALS-1 similar to that of H(2) in M. thermophila and are consistent with the conclusion that CO is an intermediate in a catabolic or anabolic pathway in Methanothrix sp. strain CALS-1; however, they could also be explained by passive equilibration of CO with a metabolic intermediate.

Carbon Monoxide, Hydrogen, and Formate Metabolism during Methanogenesis from Acetate by Thermophilic Cultures of Methanosarcina and Methanothrix Strains

PubMed Central

Zinder, S. H.; Anguish, T.

1992-01-01

CO and H2 have been implicated in methanogenesis from acetate, but it is unclear whether they are directly involved in methanogenesis or electron transfer in acetotrophic methanogens. We compared metabolism of H2, CO, and formate by cultures of the thermophilic acetotrophic methanogens Methanosarcina thermophila TM-1 and Methanothrix sp. strain CALS-1. M. thermophila accumulated H2 to partial pressures of 40 to 70 Pa (1 Pa = 0.987 × 10-5 atm), as has been previously reported for this and other Methanosarcina cultures. In contrast, Methanothrix sp. strain CALS-1 accumulated H2 to maximum partial pressures near 1 Pa. Growing cultures of Methanothrix sp. strain CALS-1 initially accumulated CO, which reached partial pressures near 0.6 Pa (some CO came from the rubber stopper) during the middle of methanogenesis; this was followed by a decrease in CO partial pressures to less than 0.01 Pa by the end of methanogenesis. Accumulation or consumption of CO by cultures of M. thermophila growing on acetate was not detected. Late-exponential-phase cultures of Methanothrix sp. strain CALS-1, in which the CO partial pressure was decreased by flushing with N2-CO2, accumulated CO to 0.16 Pa, whereas cultures to which ca. 0.5 Pa of CO was added consumed CO until it reached this partial pressure. Cyanide (1 mM) blocked CO consumption but not production. High partial pressures of H2 (40 kPa) inhibited methanogenesis from acetate by M. thermophila but not by Methanothrix sp. strain CALS-1, and 2 kPa of CO was not inhibitory to M. thermophila but was inhibitory to Methanothrix sp. strain CALS-1. Levels of CO dehydrogenase, hydrogenase, and formate dehydrogenase in Methanothrix sp. strain CALS-1 were 9.1, 0.045, and 5.8 μmol of viologen reduced min-1 mg of protein-1. These results suggest that CO plays a role in Methanothrix sp. strain CALS-1 similar to that of H2 in M. thermophila and are consistent with the conclusion that CO is an intermediate in a catabolic or anabolic pathway in Methanothrix sp. strain CALS-1; however, they could also be explained by passive equilibration of CO with a metabolic intermediate. PMID:16348788

Identifying and Controlling Contamination of Date Palm Tissue Cultures.

PubMed

Abdel-Karim, Abeer H I

2017-01-01

Fungal and bacterial contaminations are major problems facing in vitro date palm (Phoenix dactylifera L.) proliferation. To overcome this problem, we must first identify the fungal (e.g., Alternaria sp., Aspergillus niger, Penicillium sp.) and bacterial (e.g., Pseudomonas sp.) spread in date palm in vitro cultures. Incorporating fungicides (e.g., copper oxychloride, Vitavax T, and Topsin M) or antibiotics (e.g., streptomycin, Banocin, and Bencid D) at 500 mg/L in medium significantly reduces the contamination rate during various stages of in vitro date palm culture. Streptomyces chloramphenicol (pharmacy) is highly effective in reducing the bacterial contamination of date palm cultures to below 10%, as well as enhancing growth vigor.

Polysaccharides from the envelopes of heterocysts and spores of the blue-green algae Anabaena variabilis and Cylindrospermum licheniforme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cardemil, L.; Wolk, C.P.

The polysaccharides from the envelopes of heterocysts of Cylindrospermum licheniforme Kutz., and of heterocysts and spores of Anabaena variabilis Kutz., like those from the differentiated cells of Anabaena cylindrica Lemm., have a 1,3-linked backbone consisting of glucosyl and mannosyl residues in a molar ratio of approximately 3:1. As is the case with A. cylindrica the polysaccharides from A. variabilis and from the heterocysts of C. licheniforme have terminal xylosyl and galactosyl residues as side branches. In addition, the polysaccharide from C. licheniforme resembles that from A. cylindrica in having terminal mannosyl residues as side branches (absent from A. variabilis). Themore » polysaccharides from A. variabilis resemble that from A. cylindrica in having glucose-containing side branches (absent from the heterocyst polysaccharide from C. licheniforme), but in contrast to the polysaccharides from the other two species they also have terminal arabinosyl residues as side branches. All of the polysaccharides mentioned appear to be structurally related; we present tentative structures for those not previously investigated. In contrast, the envelope of spores of C. licheniforme contains only a largely 4-linked galactan. The bulk of this envelope is not polysaccharide in nature, and contains aromatic groups.« less

Simultaneous Wastewater Treatment, Algal Biomass Production and Electricity Generation in Clayware Microbial Carbon Capture Cells.

PubMed

Jadhav, Dipak A; Jain, Sumat C; Ghangrekar, Makarand M

2017-11-01

Performance of microbial carbon capture cells (MCCs), having a low-cost clayware separator, was evaluated in terms of wastewater treatment and electricity generation using algae Chlorella pyrenoidosa in MCC-1 and Anabaena ambigua in MCC-2 and without algae in a cathodic chamber of MCC-3. Higher power production was achieved in MCC-1 (6.4 W/m 3 ) compared to MCC-2 (4.29 W/m 3 ) and MCC-3 (3.29 W/m 3 ). Higher coulombic efficiency (15.23 ± 1.30%) and biomass production (66.4 ± 4.7 mg/(L*day)) in MCC-1 indicated the superiority of Chlorella over Anabaena algae for carbon capture and oxygen production to facilitate the cathodic reduction. Algal biofilm formation on the cathode surface of MCC-1 increased dissolved oxygen in the catholyte and decreased the cathodic charge transfer resistance with increase in reduction current. Electrochemical analyses revealed slow cathodic reactions and increase in internal resistance in MCC-2 (55 Ω) than MCC-1 (30 Ω), due to lower oxygen produced by Anabaena algae. Thus, biomass production in conjunction with wastewater treatment, CO 2 sequestration and electricity generation can be achieved using Chlorella algal biocathode in MCC.

Draft Genome Sequence of a Dictyoglomus sp. from an Enrichment Culture of a New Zealand Geothermal Spring

PubMed Central

Donaho, John A.; Kelley, John F.; St. John, Emily; Turner, Christina; Podar, Mircea; Stott, Matthew B.

2018-01-01

ABSTRACT A draft genome of a novel Dictyoglomus sp., NZ13-RE01, was obtained from a New Zealand hot spring enrichment culture. The 1,927,012-bp genome is similar in both size and G+C content to other Dictyoglomus spp. Like its relatives, Dictyoglomus sp. NZ13-RE01 encodes many genes involved in complex carbohydrate metabolism. PMID:29545298

Efficient Expression of Maltohexaose-Forming α-Amylase from Bacillus stearothermophilus in Brevibacillus choshinensis SP3 and Its Use in Maltose Production

PubMed Central

Duan, Xuguo

2017-01-01

The maltohexaose-forming, Ca2+-independent α-amylase gene from Bacillus stearothermophilus (AmyMH) was efficiently expressed in Brevibacillus choshinensis SP3. To improve the production of AmyMH in B. choshinensis SP3, the temperature and initial pH of culture medium were optimized. In addition, single-factor and response surface methodologies were pursued to optimize culture medium. Addition of proline to the culture medium significantly improved the production of recombinant α-amylase in B. choshinensis SP3. This improvement may result from improved cellular integrity of recombinant B. choshinensis SP3 in existence of proline. Culture medium optimization resulted in an 8-fold improvement in α-amylase yield, which reached 1.72 × 104 U·mL−1. The recombinant α-amylase was applied to the production of maltose on a laboratory scale. A maltose content of 90.72%, which could be classified as an extremely high maltose syrup, could be achieved using 15% (m/v) corn starch as the substrate. This study demonstrated that the B. choshinensis SP3 expression system was able to produce substantial quantities of recombinant α-amylase that has potential application in the starch industry. PMID:29250543

Explanations of sleep paralysis among Egyptian college students and the general population in Egypt and Denmark.

PubMed

Jalal, Baland; Simons-Rudolph, Joseph; Jalal, Bamo; Hinton, Devon E

2014-04-01

This cross-cultural study compared explanations of sleep paralysis (SP) in two countries and two groups with different levels of education in one country. Comparisons were made between individuals having experienced SP at least once in a lifetime from Cairo, Egypt (n = 89), Copenhagen, Denmark (n = 59), and the American University in Cairo, Egypt (n = 44). As hypothesized, participants from the general Egyptian population were more likely to endorse supernatural causal explanation of their SP compared to participants from Denmark; participants from the American University in Cairo were less likely to endorse supernatural causes of their SP compared to participants from the general Egyptian population. Moreover, participants from the American University in Cairo were marginally significantly more likely to endorse supernatural causes of their SP compared to participants from Denmark. Additionally, we explored which culturally bound explanations and beliefs about SP existed in Egypt and Denmark. We found that nearly half (48%) of the participants from the general Egyptian population believed their SP to be caused by the Jinn, a spirit-like creature with roots in Islamic tradition, which constitutes a culturally bound interpretation of the phenomenology of SP in this region of the world. Case studies are presented to illustrate these findings.

Phylogenetic Analysis and Antimicrobial Profiles of Cultured Emerging Opportunistic Pathogens (Phyla Actinobacteria and Proteobacteria) Identified in Hot Springs

PubMed Central

Jardine, Jocelyn Leonie; Mavumengwana, Vuyo

2017-01-01

Hot spring water may harbour emerging waterborne opportunistic pathogens that can cause infections in humans. We have investigated the diversity and antimicrobial resistance of culturable emerging and opportunistic bacterial pathogens, in water and sediment of hot springs located in Limpopo, South Africa. Aerobic bacteria were cultured and identified using 16S ribosomal DNA (rDNA) gene sequencing. The presence of Legionella spp. was investigated using real-time polymerase chain reaction. Isolates were tested for resistance to ten antibiotics representing six different classes: β-lactam (carbenicillin), aminoglycosides (gentamycin, kanamycin, streptomycin), tetracycline, amphenicols (chloramphenicol, ceftriaxone), sulphonamides (co-trimoxazole) and quinolones (nalidixic acid, norfloxacin). Gram-positive Kocuria sp. and Arthrobacter sp. and gram-negative Cupriavidus sp., Ralstonia sp., Cronobacter sp., Tepidimonas sp., Hafnia sp. and Sphingomonas sp. were isolated, all recognised as emerging food-borne pathogens. Legionella spp. was not detected throughout the study. Isolates of Kocuria, Arthrobacter and Hafnia and an unknown species of the class Gammaproteobacteria were resistant to two antibiotics in different combinations of carbenicillin, ceftriaxone, nalidixic acid and chloramphenicol. Cronobacter sp. was sensitive to all ten antibiotics. This study suggests that hot springs are potential reservoirs for emerging opportunistic pathogens, including multiple antibiotic resistant strains, and highlights the presence of unknown populations of emerging and potential waterborne opportunistic pathogens in the environment. PMID:28914802

Fungi Associated with Materials’ Biodeterioration in the Humid Tropics

DTIC Science & Technology

1983-01-01

Cephalosphorium sp and Rhizopus sp. The mineral salts cultures again showed the presence of Trichoderma sp and Cephalosporium sp. The fungus Fusarium sp was... Trichoderma SD #1 A/ Ce halosvorium sp a Curvlara sp Phoma SD Unkn-own #? Tropicalized Cotton Cephalosporlum sp a/ Trichoderna SD #1 a! (2 weeks...sp Cotton None Trichoderma sp #2 a usarium SD i/ Phoma SD A/ Te-iFaosorium SD Cotton Cephaloseoriun sD a/ Fusariun SD a/ (2 weeks additional Aroasidu

The role of lactic acid bacteria (Lactobacillus sp yel133) from beef in inhibiting of microbial contaminants on various fillers of starter culture

NASA Astrophysics Data System (ADS)

Yunilas; Mirwandhono, E.

2018-02-01

The role of Lactic Acid Bacteria (LAB) on the starter culture can be seen from the ability to grow and suppress the growth of microbial contaminants (fungi). The research aimed to investigate the role of LAB (Lactobacillus sp YEL133) in inhibiting microbial contaminants (fungi) on starter cultures of various fillers. The materials used in this research was Lactobacillus sp YEL133 from beef and various fillers (rice flour, corn starch and wheat flour). The research methods used completely randomized design (CRD) with 3 treatments and 4 replications. The treatments of this research was P1(rice flour), P2 (corn starch) and P3 (wheat flour) that inoculated with Lactobacillus sp YEL133. Parameters which is observed such as: growth of lactic acid bacteria, total microbes and total fungi as microbial contaminants. The results showed that the starter culture with a filler material of rice flour produce lactic acid bacteria and microbes were highly significant (P <0.01) for corn starch and wheat flour, as well as able to suppress the growth of microbial contaminants (fungi). The conclusion of the research is the use Lactobacillus sp YEL133 can suppress the growth of fungi on the starter culture using rice flour.

Properties of Polyhydroxyalkanoate Granules and Bioemulsifiers from Pseudomonas sp. and Burkholderia sp. Isolates Growing on Glucose.

PubMed

Sacco, Laís Postai; Castellane, Tereza Cristina Luque; Lopes, Erica Mendes; de Macedo Lemos, Eliana Gertrudes; Alves, Lúcia Maria Carareto

2016-03-01

A Burkholderia and Pseudomonas species designated as AB4 and AS1, respectively, were isolated from soil containing decomposing straw or sugar cane bagasse collected from Brazil. This study sought to evaluate the capacities of culture media, cell-free medium, and crude lysate preparations (containing PHB inclusion bodies) from bacterial cell cultures to stabilize emulsions with several hydrophobic compounds. Four conditions showed good production of bioemulsifiers (E24 ≥ 50 %), headed by substantially cell-free media from bacterial cell cultures in which bacterial isolates from Burkholderia sp. strain AB4 and Pseudomonas sp. strain AS1 were grown. Our results revealed that the both isolates (AB4 and AS1 strains) exhibited high emulsification indices (indicating usefulness in bioremediation) and good stabilities.

Alkane Biosynthesis Genes in Cyanobacteria and Their Transcriptional Organization

PubMed Central

Klähn, Stephan; Baumgartner, Desirée; Pfreundt, Ulrike; Voigt, Karsten; Schön, Verena; Steglich, Claudia; Hess, Wolfgang R.

2014-01-01

In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl–acyl carrier protein reductase and aldehyde deformylating oxygenase. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short-chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado) and sll0209 (aar), which give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313, and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in cyanobacteria. PMID:25022427

Draft Genome Sequence of a Dictyoglomus sp. from an Enrichment Culture of a New Zealand Geothermal Spring.

PubMed

Reysenbach, Anna-Louise; Donaho, John A; Kelley, John F; St John, Emily; Turner, Christina; Podar, Mircea; Stott, Matthew B

2018-03-15

A draft genome of a novel Dictyoglomus sp., NZ13-RE01, was obtained from a New Zealand hot spring enrichment culture. The 1,927,012-bp genome is similar in both size and G+C content to other Dictyoglomus spp. Like its relatives, Dictyoglomus sp. NZ13-RE01 encodes many genes involved in complex carbohydrate metabolism. Copyright © 2018 Reysenbach et al.

Is it feasible to diagnose catheter-related candidemia without catheter withdrawal?

PubMed

Fernández-Cruz, Ana; Martín-Rabadán, Pablo; Suárez-Salas, Marisol; Rojas-Wettig, Loreto; Pérez, María Jesús; Guinea, Jesús; Guembe, María; Peláez, Teresa; Sánchez-Carrillo, Carlos; Bouza, Emilio

2014-07-01

Many bloodstream infections (BSI) in patients with central venous catheters (CVC) are not catheter-related (CR). Assessment of catheter involvement without catheter withdrawal has not been studied in candidemia. We assessed the value of conservative techniques to evaluate catheters as the origin of candidemia in patients with CVC in a prospective cohort study (superficial Gram stain and culture, Kite technique (Gram stain and culture of the first 1 cm blood drawn from the CVC), proportion of positive blood cultures (PPBCs), differential time to positivity (DTP), and minimal time to positivity (MTP)). All catheters were cultured at withdrawal. From June 2008 to January 2012, 22 cases fulfilled the inclusion criteria. CR-candidemia (CRC) was confirmed in 10. Validity values for predicting CRC were: superficial Gram stain (S, 30%; Sp, 81.83%; PPV, 60%; NPV, 56.3%; Ac, 57.1%), superficial cultures (S, 40%; Sp, 75%; PPV, 57.1%; NPV, 60%; Ac, 59.1%), Kite Gram stain (S, 33.3%; Sp, 66.7%; PPV, 50%; NPV, 50%; Ac, 50%), Kite culture (S, 80%; Sp, 66.7%; PPV, 66.7%; NPV, 80%; Ac, 72.7%), PPBC (S, 50%; Sp, 41.7%; PPV, 41.7%; NPV, 50.0%; Ac, 45.5%), DTP (S, 100%; Sp, 33.3%; PPV, 55.6%; NPV, 100%; Ac, 63.6%), and MTTP (S, 70%; Sp, 58.3%; PPV, 58.3%; NPV, 70%; Ac, 63.6%). While combinations of two tests improved sensitivity and NPV, more than two tests did not improve validity values. Classic tests to assess CR-BSI caused by bacteria cannot be reliably used to diagnose CRC. Combinations of tests could be useful, but more and larger studies are required. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Substance P enhances proliferation and paracrine potential of adipose-derived stem cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Suna; Piao, Jiyuan; Son, Youngsook

Stem cells have tremendous promise to treat intractable diseases. Notably, adipose-derived stem cells (ADSCs) are actively being investigated because of ease of sampling and high repopulation capacity in vitro. ADSCs can exert a therapeutic effect through differentiation and paracrine potential, and these actions have been proven in many diseases, including cutaneous and inflammatory diseases. Transplantation of ADSCs necessitates therapeutic quantities and thus, long term ex vivo culture of ADSCs. However, this procedure can impair the activity of ADSCs and provoke cellular senescence, leading to low efficacy in vivo. Accordingly, strategies to restore cellular activity and inhibit senescence of stem cells during ex vivo culturemore » are needed for stem cell-based therapies. This study evaluated a potential supplementary role of Substance P (SP) in ADSC ex vivo culture. After confirming that the ADSC cell cycle was damaged by passage 6 (p6), ADSCs at p6 were cultured with SP, and their proliferation rates, cumulative cell numbers, cytokine profiles, and impact on T/endothelial cells were assessed. Long-term culture weakened proliferation ability and secretion of the cytokines, transforming growth factor-beta 1 (TGF-beta1), vascular endothelial growth factor (VEGF), and stromal cell derived factor-1 alpha (SDF-1alpha) in ADSCs. However, SP treatment reduced the population doubling time (PDT), enabling gain of a sufficient number of ADSCs at early passages. In addition, SP restored cytokine secretion, enhancing the ADSC-mediated paracrine effect on T cell and human umbilical vein endothelial cells (HUVECs). Taken together, these results suggest that SP can retain the therapeutic effect of ADSCs by elevating their proliferative and paracrine potential in ex vivo culture. - Highlights: • Long-term culture of ADSCs leads to cell senescence. • Paracrine potential of ADSC decreases as passage number increases. • SP enhances the weakened proliferation capacity of ADSCs. • SP stimulates cytokine secretion from ADSC with impaired paracrine potential.« less

Phylogenetically distant clade of Nostoc-like taxa with the description of Aliinostoc gen. nov. and Aliinostoc morphoplasticum sp. nov.

PubMed

Bagchi, Suvendra Nath; Dubey, Neelam; Singh, Prashant

2017-09-01

Nostoc is a complex and tough genus to differentiate, and its morphological plasticity makes it taxonomically complicated. Its cryptic diversity and almost no distinguishable morphological characteristics make this genus incredibly heterogeneous to evaluate on taxonomic scales. The strain NOS, isolated from a eutrophic water body, is being described as a new genus Aliinostoc with the strain showing motile hormogonia with gas vesicles as an atypical feature, which is currently considered as the diacritical feature of the genus but should be subjected to critical evaluation in the near future. The phylogenetic placement of Aliinostoc along with some other related sequences of Nostoc clearly separated this clade from Nostoc sensu stricto with high bootstrap support and robust topology in all the methods tested, thus providing strong proof of the taxa being representative of a new genus which morphologically appears to be Nostoc-like. Subsequent phylogenetic assessment using the rbcL, psbA, rpoC1 and tufA genes was done with the aim of facilitating future multi-locus studies on the proposed genus for better taxonomic clarity and resolution. Folding of the 16S-23S internal transcribed spacer region and subsequent comparisons with members of the genera Nostoc, Anabaena, Aulosira, Cylindrospermum, Sphaerospermopsis, Raphidiopsis, Desmonostoc and Mojavia gave entirely new secondary structures for the D1-D1' and box-B helix. Clear and separate clustering from Nostoc sensu stricto supports the establishment of Aliinostoc gen. nov. with the type species being Aliinostoc morphoplasticum sp. nov. in accordance with the International Code of Nomenclature for algae, fungi and plants.

Screening and selection of most potent diazotrophic cyanobacterial isolate exhibiting natural tolerance to rice field herbicides for exploitation as biofertilizer.

PubMed

Singh, Surendra; Datta, Pallavi

2006-01-01

Periodic applications of heavy dosages of herbicides in modern rice-agriculture are a necessary evil for obtaining high crop productivity. Such herbicides are not only detrimental to weeds but biofertilizer strains of diazotrophic cyanobacteria also. It is therefore, essential to screen and select such biofertilizer strains of diazotrophic cyanobacteria exhibiting natural tolerance to common rice-field herbicides that can be further improved by mutational techniques to make biofertilizer technology a viable one. Therefore, efforts have been made to screen five dominant diazotrophic cyanobacterial forms e.g. filamentous heterocystous Nostoc punctiforme , Nostoc calcicola , Anabaena variabilis and unicellular Gloeocapsa sp. and Aphanocapsa sp. along with standard laboratory strain Nostoc muscorum ISU against increasing concentrations (0-100 mg l(-1) of four commercial grade common rice-field herbicides i.e. Arozin, Butachlor, Alachlor and 2,4-D under diazotrophic growth conditions. The lethal and IGC(50) concentrations for all four herbicides tested were found highest for A. variabilis as compared to other test cyanobacteria. The lowest reduction in chlorophyll a content, photosynthetic oxygen evolution, and N(2)-fixation was found in A. variabilis as compared to other rice field isolates and standard laboratory strain N. muscorum ISU. On the basis of prolong survival potential and lowest reductions in vital metabolic activities tested at IGC(50) concentration of four herbicides, it is concluded that A. variabilis is the most potent and promising cyanobacterial isolate as compared with other forms. This could be further improved by mutational techniques for exploitation as most potential and viable biofertilizer strain.

Hydrogen peroxide treatment promotes chlorophytes over toxic cyanobacteria in a hyper-eutrophic aquaculture pond.

PubMed

Yang, Zhen; Buley, Riley P; Fernandez-Figueroa, Edna G; Barros, Mario U G; Rajendran, Soorya; Wilson, Alan E

2018-05-12

Controlling blooms of toxigenic phytoplankton, including cyanobacteria, is a high priority for managers of aquatic systems that are used for drinking water, recreation, and aquaculture production. Although a variety of treatment approaches exist, hydrogen peroxide (H 2 O 2 ) has the potential to be an effective and ecofriendly algaecide given that this compound may select against cyanobacteria while not producing harmful residues. To broadly evaluate the effectiveness of H 2 O 2 on toxigenic phytoplankton, we tested multiple concentrations of H 2 O 2 on (1) four cyanobacterial cultures, including filamentous Anabaena, Cylindrospermopsis, and Planktothrix, and unicellular Microcystis, in a 5-day laboratory experiment and (2) a dense cyanobacterial bloom in a 7-day field experiment conducted in a nutrient-rich aquaculture pond. In the laboratory experiment, half-maximal effective concentrations (EC 50 ) were similar for Anabaena, Cylindrospermopsis, and Planktothrix (average EC 50  = 0.41 mg L -1 ) but were ∼10x lower than observed for Microcystis (EC 50  = 5.06 mg L -1 ). Results from a field experiment in an aquaculture pond showed that ≥1.3 and ≥ 6.7 mg L -1 of H 2 O 2 effectively eliminated Planktothrix and Microcystis, respectively. Moreover, 6.7 mg L -1 of H 2 O 2 reduced microcystin and enhanced phytoplankton diversity, while causing relatively small negative effects on zooplankton abundance. In contrast, 20 mg L -1 of H 2 O 2 showed the greatest negative effect on zooplankton. Our results demonstrate that H 2 O 2 can be an effective, rapid algaecide for controlling toxigenic cyanobacteria when properly dosed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Isolation of a selected microbial consortium capable of degrading methyl parathion and p-nitrophenol from a contaminated soil site.

PubMed

Pino, Nancy J; Dominguez, Maria C; Penuela, Gustavo A

2011-01-01

A bacterial consortium with the ability to degrade methyl parathion and p-nitrophenol, using these compounds as the only carbon source, was obtained by selective enrichment in a medium with methyl parathion. Samples were taken from Moravia, Medellin; an area that is highly contaminated, owing to the fact that it was used as a garbage dump from 1974 to 1982. Acinetobacter sp, Pseudomonas putida, Bacillus sp, Pseudomonas aeruginosa Citrobacter freundii, Stenotrophomonas sp, Flavobacterium sp, Proteus vulgaris, Pseudomonas sp, Acinetobacter sp, Klebsiella sp and Proteus sp were the microorganisms identified within the consortium. In culture, the consortium was able to degrade 150 mg L⁻¹ of methyl-parathion and p-nitrophenol in 120 h, but after adding glucose or peptone to the culture, the time of degradation decreased to 24 h. In soil, the consortium was also able to degrade 150 mg L⁻¹ of methyl parathion in 120 h at different depths and also managed to decrease the toxicity.

Corrosive Metabolic Activity of Desulfovibrio sp. on 316L Stainless Steel

NASA Astrophysics Data System (ADS)

Arkan, Simge; Ilhan-Sungur, Esra; Cansever, Nurhan

2016-12-01

The present study investigated the effects of chemical parameters (SO4 2-, PO4 3-, Cl-, pH) and the contents of extracellular polymeric substances (EPS) regarding the growth of Desulfovibrio sp. on the microbiologically induced corrosion of 316L stainless steel (SS). The experiments were carried out in laboratory-scaled test and control systems. 316L SS coupons were exposed to Desulfovibrio sp. culture over 720 h. The test coupons were removed at specific sampling times for enumeration of Desulfovibrio sp., determination of the corrosion rate by the weight loss measurement method and also for analysis of carbohydrate and protein in the EPS. The chemical parameters of the culture were also established. Biofilm/film formation and corrosion products on the 316L SS surfaces were investigated by scanning electron microscopy and energy-dispersive x-ray spectrometry analyses in the laboratory-scaled systems. It was found that Desulfovibrio sp. led to the corrosion of 316L SS. Both the amount of extracellular protein and chemical parameters (SO4 2- and PO4 3-) of the culture caused an increase in the corrosion of metal. There was a significantly positive relationship between the sessile and planktonic Desulfovibrio sp. counts ( p < 0.01). It was detected that the growth phases of the sessile and planktonic Desulfovibrio sp. were different from each other and the growth phases of the sessile Desulfovibrio sp. vary depending on the subspecies of Desulfovibrio sp. and the type of metal when compared with the other published studies.

Aggregation of Sea Urchin Phagocytes Is Augmented In Vitro by Lipopolysaccharide

PubMed Central

Majeske, Audrey J.; Bayne, Christopher J.; Smith, L. Courtney

2013-01-01

Development of protocols and media for culturing immune cells from marine invertebrates has not kept pace with advancements in mammalian immune cell culture, the latter having been driven by the need to understand the causes of and develop therapies for human and animal diseases. However, expansion of the aquaculture industry and the diseases that threaten these systems creates the need to develop cell and tissue culture methods for marine invertebrates. Such methods will enable us to better understand the causes of disease outbreaks and to develop means to avoid and remedy epidemics. We report a method for the short-term culture of phagocytes from the purple sea urchin, Strongylocentrotus purpuratus, by modifying an approach previously used to culture cells from another sea urchin species. The viability of cultured phagocytes from the purple sea urchin decreases from 91.6% to 57% over six days and phagocyte morphology changes from single cells to aggregates leading to the formation of syncytia-like structures. This process is accelerated in the presence of lipopolysaccharide suggesting that phagocytes are capable of detecting this molecular pattern in culture conditions. Sea urchin immune response proteins, called Sp185/333, are expressed on the surface of a subset of phagocytes and have been associated with syncytia-like structures. We evaluated their expression in cultured phagocytes to determine their possible role in cell aggregation and in the formation of syncytia-like structures. Between 0 and 3 hr, syncytia-like structures were observed in cultures when only ∼10% of the cells were positive for Sp185/333 proteins. At 24 hr, ∼90% of the nuclei were Sp185/333-positive when all of the phagocytes had aggregated into syncytia-like structures. Consequently, we conclude that the Sp185/333 proteins do not have a major role in initiating the aggregation of cultured phagocytes, however the Sp185/333 proteins are associated with the clustered nuclei within the syncytia-like structures. PMID:23613847

Aggregation of sea urchin phagocytes is augmented in vitro by lipopolysaccharide.

PubMed

Majeske, Audrey J; Bayne, Christopher J; Smith, L Courtney

2013-01-01

Development of protocols and media for culturing immune cells from marine invertebrates has not kept pace with advancements in mammalian immune cell culture, the latter having been driven by the need to understand the causes of and develop therapies for human and animal diseases. However, expansion of the aquaculture industry and the diseases that threaten these systems creates the need to develop cell and tissue culture methods for marine invertebrates. Such methods will enable us to better understand the causes of disease outbreaks and to develop means to avoid and remedy epidemics. We report a method for the short-term culture of phagocytes from the purple sea urchin, Strongylocentrotus purpuratus, by modifying an approach previously used to culture cells from another sea urchin species. The viability of cultured phagocytes from the purple sea urchin decreases from 91.6% to 57% over six days and phagocyte morphology changes from single cells to aggregates leading to the formation of syncytia-like structures. This process is accelerated in the presence of lipopolysaccharide suggesting that phagocytes are capable of detecting this molecular pattern in culture conditions. Sea urchin immune response proteins, called Sp185/333, are expressed on the surface of a subset of phagocytes and have been associated with syncytia-like structures. We evaluated their expression in cultured phagocytes to determine their possible role in cell aggregation and in the formation of syncytia-like structures. Between 0 and 3 hr, syncytia-like structures were observed in cultures when only ~10% of the cells were positive for Sp185/333 proteins. At 24 hr, ~90% of the nuclei were Sp185/333-positive when all of the phagocytes had aggregated into syncytia-like structures. Consequently, we conclude that the Sp185/333 proteins do not have a major role in initiating the aggregation of cultured phagocytes, however the Sp185/333 proteins are associated with the clustered nuclei within the syncytia-like structures.

Substance P and neurokinin 1 receptors as potential therapeutic targets in children with OSA.

PubMed

Gozal, David; Kim, Jinkwan; Bhattacharjee, Rakesh; Goldman, Julie L; Kheirandish-Gozal, Leila

2014-05-01

Increased substance P (SP) levels and abundant expression of neurokinin (NK) 1 receptor in adenotonsillar tissues of children with OSA but not recurrent tonsillar infection (RI) suggest that NK1 antagonists could be useful in treating OSA. The effects of SP and the NK1 antagonist GR-82334 were examined on mixed cell cultures prepared from dissociated tonsils harvested intraoperatively from children with OSA and RI. Proliferation was assessed by [3H]-thymidine or 5-ethynyl-2'-deoxyuridine incorporation, and inflammatory cytokine production (tumor necrosis factor [TNF]-α, IL-6, IL-1β) was assessed in supernatants by enzyme-linked immunosorbent assay. SP elicited dose-dependent increases in tonsillar cell proliferation in mixed cell cultures from children with OSA but not with RI (P < .0001). The NK1 antagonist exhibited dose-dependent reductions in cellular proliferative rates in OSA-derived cell cultures but not in RI-derived mixed cell cultures (P < .00001). SP treatment was associated with increased TNF-α and IL-6 production, and GR-82334 abrogated SP effects, as well as reduced basal cytokine release (P < .0001). SP pathways appear to underlie intrinsic proliferative and inflammatory signaling pathways in tonsillar tissues from children with OSA but not with RI. Selective disruption of these pathways may provide nonsurgical alternatives for prevention and treatment of pediatric OSA.

Evaluation of Culture Conditions to Obtain Fatty Acids from Saline Microalgae Species: Dunaliella salina, Sinecosyfis sp., and Chroomonas sp.

PubMed Central

Castilla Casadiego, D. A.; Albis Arrieta, A. R.; Angulo Mercado, E. R.; Cervera Cahuana, S. J.; Baquero Noriega, K. S.; Suárez Escobar, A. F.; Morales Avendaño, E. D.

2016-01-01

The use of the saline microalgae, Dunaliella salina, Sinecosyfis sp., and Chroomonas sp., was explored as an alternative source for the production of fatty acids using fertilizer and glycerol as culture media. The nutrient medium used contained “Nutrifoliar,” a commercial fertilizer, and/or glycerol, in natural sea water. The microalgae were placed in cultures with different conditions. The parameters that favored the largest production of fatty acids were 24 hours of agitation and illumination, 1620 L/day of air supply, 2.25 L of air/min, and a temperature of 32°C using “Nutrifoliar” as the culture media. Results indicated that, from 3 g of microalgae in wet base of Chroomonas sp., 54.43 mg of oil was produced. The chromatographic characterization of oil obtained revealed the presence of essential fatty acids such as 9,12,15-octadecatrienoic acid (omega-3) and 4,7,10-hexadecatrienoic acid (omega-6) from the species Dunaliella salina. On the other hand, 9,12-octadecadienoic acid (omega-6) and cis-11-eicosenoic acid (omega-9) were identified from the species Chroomonas sp. The temperature variations played an important role in the velocity of growth or the production of the algae biomass, the amount of oil, and the ability to produce fatty acids. PMID:27376085

Evaluation of Culture Conditions to Obtain Fatty Acids from Saline Microalgae Species: Dunaliella salina, Sinecosyfis sp., and Chroomonas sp.

PubMed

Castilla Casadiego, D A; Albis Arrieta, A R; Angulo Mercado, E R; Cervera Cahuana, S J; Baquero Noriega, K S; Suárez Escobar, A F; Morales Avendaño, E D

2016-01-01

The use of the saline microalgae, Dunaliella salina, Sinecosyfis sp., and Chroomonas sp., was explored as an alternative source for the production of fatty acids using fertilizer and glycerol as culture media. The nutrient medium used contained "Nutrifoliar," a commercial fertilizer, and/or glycerol, in natural sea water. The microalgae were placed in cultures with different conditions. The parameters that favored the largest production of fatty acids were 24 hours of agitation and illumination, 1620 L/day of air supply, 2.25 L of air/min, and a temperature of 32°C using "Nutrifoliar" as the culture media. Results indicated that, from 3 g of microalgae in wet base of Chroomonas sp., 54.43 mg of oil was produced. The chromatographic characterization of oil obtained revealed the presence of essential fatty acids such as 9,12,15-octadecatrienoic acid (omega-3) and 4,7,10-hexadecatrienoic acid (omega-6) from the species Dunaliella salina. On the other hand, 9,12-octadecadienoic acid (omega-6) and cis-11-eicosenoic acid (omega-9) were identified from the species Chroomonas sp. The temperature variations played an important role in the velocity of growth or the production of the algae biomass, the amount of oil, and the ability to produce fatty acids.

Anti-Methicillin Resistant Staphylococcus aureus Activity and Optimal Culture Condition of Streptomyces sp. SUK 25

PubMed Central

Siti Junaidah, Ahmad; Suhaini, Sudi; Mohd Sidek, Hasidah; Basri, Dayang Fredalina; Zin, Noraziah Mohamad

2015-01-01

Background: The potential of secondary metabolites extracted from Streptomyces sp. to treat bacterial infections including infections with Staphylococcus aureus is previously documented. The current study showed significant antimicrobial activities associated with endophytic Streptomyces sp. isolated from medicinal plants in Peninsular Malaysia. Objectives: The current study aimed to determine anti-methicillin-resistant-Staphylococcus aureus (MRSA) activities of Streptomyces sp. isolates. Materials and Methods: Disc diffusion and Minimum Inhibitory Concentration (MIC) assay were used to determine the antibacterial activity of Streptomyces sp. isolates. Optimization of fermentation parameters for the most potent anti-MRSA extract in terms of medium type, pH, aeration rate, and culture period was also carried out. Lastly, toxicity of the extract against Chang liver cells was determined employing the MTT, 2- (3, 5- diphenyltetrazol-2-ium-2-yl) -4, 5-dimethyl -1, 3 - thiazole; bromide assay. Results: The results indicated Streptomyces sp. SUK 25 isolates showed the most potent anti-MRSA activity. Disc diffusion assay revealed that spread plate technique was more efficient in screening anti-MRSA activity compared to pour plate (P < 0.05). To determine anti–MRSA MIC of Streptomyces sp. SUK 25, Thronton media was used. Therefore, MIC was determined as 2.44 ± 0.01 µg/mL, and accordingly, the lowest MIC was 1.95 µg/mL based on a seven-day culture, pH7, and aeration rate of 140 rpm. The crude extract was not toxic against Chang liver cells (IC50 = 43.31 ± 1.24 µg/mL). Conclusions: The Streptomyces sp. SUK 25 culturing was optimized using Thronton media, at pH 7 and aeration of 140 rpm. Further isolation and identification of bioactive compounds will develop anti-MRSA therapeutics. PMID:26060562

Cultural Resources Investigations of the West Bank Hurricane Protection Project, Jefferson Parish, Louisiana

DTIC Science & Technology

1989-09-01

most common understory plants include thistle (Carduus sp.), violet (Viola sp.), bur- marigold (Bidens laevis), and ferns. Drained cypress-tupelo swamp... marigold (Bidens laevis), violet (Viola sp.), thistle (Carduus sp.), and Southern shield fern (Thelypteris kunthil). Drained marsh makes up the

Mesosecrin: a secreted glycoprotein produced in abundance by human mesothelial, endothelial, and kidney epithelial cells in culture

PubMed Central

1987-01-01

Human mesothelial cells, endothelial cells, and type II kidney epithelial cells growing in culture devote approximately 3% of their total protein synthesis to the production of an Mr approximately 46-kD, pI 7.1, secreted glycoprotein (designated Sp46). Fibroblasts make about 1/10th as much Sp46 as these cell types, and their synthesis is dependent upon hydrocortisone. Keratinocytes, urothelial cells, conjunctival epithelial cells, and mammary epithelial cells do not make detectable amounts of Sp46. Mesothelial cells secrete Sp46 onto the substratum, and from there it is subsequently released into the medium. Immunofluorescence analysis using specific antisera discloses that Sp46 is deposited beneath cells as a fine coating on the substratum. In sparse cultures, Sp46 is detected in trails behind motile cells. In contrast, secreted fibronectin coalesces into fibers, most of which remain in contact with and on top of the cells; thus Sp46 does not preferentially bind to fibronectin. About 6 kD of the mass of human Sp46 is N-linked oligosaccharide, which is terminally sialated before secretion. Sp46 has a low glycine content, indicating that it is not a collagenlike protein. Its NH2-terminal sequence over the first 40 amino acids does not resemble any protein for which sequence information is available. Sp46 appears to be a novel extracellular glycoprotein, high- level constitutive expression of which is restricted to mesoderm- derived epithelial and endothelial cells. We therefore propose for it the name "mesosecrin." PMID:3543023

Effects of Bacterial Community Members on the Proteome of the Ammonia-Oxidizing Bacterium Nitrosomonas sp. Strain Is79

PubMed Central

Sedlacek, Christopher J.; Nielsen, Susanne; Greis, Kenneth D.; Haffey, Wendy D.; Revsbech, Niels Peter; Ticak, Tomislav; Laanbroek, Hendrikus J.

2016-01-01

ABSTRACT Microorganisms in the environment do not exist as the often-studied pure cultures but as members of complex microbial communities. Characterizing the interactions within microbial communities is essential to understand their function in both natural and engineered environments. In this study, we investigated how the presence of a nitrite-oxidizing bacterium (NOB) and heterotrophic bacteria affect the growth and proteome of the chemolithoautotrophic ammonia-oxidizing bacterium (AOB) Nitrosomonas sp. strain Is79. We investigated Nitrosomonas sp. Is79 in co-culture with Nitrobacter winogradskyi, in co-cultures with selected heterotrophic bacteria, and as a member of the nitrifying enrichment culture G5-7. In batch culture, N. winogradskyi and heterotrophic bacteria had positive effects on the growth of Nitrosomonas sp. Is79. An isobaric tag for relative and absolute quantification (iTRAQ) liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach was used to investigate the effect of N. winogradskyi and the co-cultured heterotrophic bacteria from G5-7 on the proteome of Nitrosomonas sp. Is79. In co-culture with N. winogradskyi, several Nitrosomonas sp. Is79 oxidative stress response proteins changed in abundance, with periplasmic proteins increasing and cytoplasmic proteins decreasing in abundance. In the presence of heterotrophic bacteria, the abundance of proteins directly related to the ammonia oxidation pathway increased, while the abundance of proteins related to amino acid synthesis and metabolism decreased. In summary, the proteome of Nitrosomonas sp. Is79 was differentially influenced by the presence of either N. winogradskyi or heterotrophic bacteria. Together, N. winogradskyi and heterotrophic bacteria reduced the oxidative stress for Nitrosomonas sp. Is79, which resulted in more efficient metabolism. IMPORTANCE Aerobic ammonia-oxidizing microorganisms play an important role in the global nitrogen cycle, converting ammonia to nitrite. In their natural environment, they coexist and interact with nitrite oxidizers, which convert nitrite to nitrate, and with heterotrophic microorganisms. The presence of nitrite oxidizers and heterotrophic bacteria has a positive influence on the growth of the ammonia oxidizers. Here, we present a study investigating the effect of nitrite oxidizers and heterotrophic bacteria on the proteome of a selected ammonia oxidizer in a defined culture to elucidate how these two groups improve the performance of the ammonia oxidizer. The results show that the presence of a nitrite oxidizer and heterotrophic bacteria reduced the stress for the ammonia oxidizer and resulted in more efficient energy generation. This study contributes to our understanding of microbe-microbe interactions, in particular between ammonia oxidizers and their neighboring microbial community. PMID:27235442

Endoglucanase and xylanase production by Bacillus sp. AR03 in co-culture.

PubMed

Hero, Johan S; Pisa, José H; Perotti, Nora I; Romero, Cintia M; Martínez, María A

2017-07-03

The behavior of three isolates retrieved from different cellulolytic consortia, Bacillus sp. AR03, Paenibacillus sp. AR247 and Achromobacter sp. AR476-2, were examined individually and as co-cultures in order to evaluate their ability to produce extracellular cellulases and xylanases. Utilizing a peptone-based medium supplemented with carboxymethyl cellulose (CMC), an increase estimation of 1.30 and 1.50 times was obtained by the co-culture containing the strains AR03 and AR247, with respect to enzyme titles registered by their individual cultivation. On the contrary, the extracellular enzymatic production decreased during the co-cultivation of strain AR03 with the non-cellulolytic Achromobacter sp. AR476-2. The synergistic behavior observed through the combined cultivation of the strains AR03 and AR247 might be a consequence of the consumption by Paenibacillus sp. AR247 of the products of the CMC hydrolysis (i.e., cellobiose and/or cello-oligosaccharides), which were mostly generated by the cellulase producer Bacillus sp. AR03. The effect observed could be driven by the requirement to fulfill the nutritional supply from both strains on the substrate evaluated. These results would contribute to a better description of the degradation of the cellulose fraction of the plant cell walls in nature, expected to an efficient utilization of renewable sources.

Microbiota Influences Morphology and Reproduction of the Brown Alga Ectocarpus sp.

PubMed Central

Tapia, Javier E.; González, Bernardo; Goulitquer, Sophie; Potin, Philippe; Correa, Juan A.

2016-01-01

Associated microbiota play crucial roles in health and disease of higher organisms. For macroalgae, some associated bacteria exert beneficial effects on nutrition, morphogenesis and growth. However, current knowledge on macroalgae–microbiota interactions is mostly based on studies on green and red seaweeds. In this study, we report that when cultured under axenic conditions, the filamentous brown algal model Ectocarpus sp. loses its branched morphology and grows with a small ball-like appearance. Nine strains of periphytic bacteria isolated from Ectocarpus sp. unialgal cultures were identified by 16S rRNA sequencing, and assessed for their effect on morphology, reproduction and the metabolites secreted by axenic Ectocarpus sp. Six of these isolates restored morphology and reproduction features of axenic Ectocarpus sp. Bacteria-algae co-culture supernatants, but not the supernatant of the corresponding bacterium growing alone, also recovered morphology and reproduction of the alga. Furthermore, colonization of axenic Ectocarpus sp. with a single bacterial isolate impacted significantly the metabolites released by the alga. These results show that the branched typical morphology and the individuals produced by Ectocarpus sp. are strongly dependent on the presence of bacteria, while the bacterial effect on the algal exometabolome profile reflects the impact of bacteria on the whole physiology of this alga. PMID:26941722

Microbiota Influences Morphology and Reproduction of the Brown Alga Ectocarpus sp.

PubMed

Tapia, Javier E; González, Bernardo; Goulitquer, Sophie; Potin, Philippe; Correa, Juan A

2016-01-01

Associated microbiota play crucial roles in health and disease of higher organisms. For macroalgae, some associated bacteria exert beneficial effects on nutrition, morphogenesis and growth. However, current knowledge on macroalgae-microbiota interactions is mostly based on studies on green and red seaweeds. In this study, we report that when cultured under axenic conditions, the filamentous brown algal model Ectocarpus sp. loses its branched morphology and grows with a small ball-like appearance. Nine strains of periphytic bacteria isolated from Ectocarpus sp. unialgal cultures were identified by 16S rRNA sequencing, and assessed for their effect on morphology, reproduction and the metabolites secreted by axenic Ectocarpus sp. Six of these isolates restored morphology and reproduction features of axenic Ectocarpus sp. Bacteria-algae co-culture supernatants, but not the supernatant of the corresponding bacterium growing alone, also recovered morphology and reproduction of the alga. Furthermore, colonization of axenic Ectocarpus sp. with a single bacterial isolate impacted significantly the metabolites released by the alga. These results show that the branched typical morphology and the individuals produced by Ectocarpus sp. are strongly dependent on the presence of bacteria, while the bacterial effect on the algal exometabolome profile reflects the impact of bacteria on the whole physiology of this alga.

Cr(VI) reduction from contaminated soils by Aspergillus sp. N2 and Penicillium sp. N3 isolated from chromium deposits.

PubMed

Fukuda, Tsubasa; Ishino, Yasuhiro; Ogawa, Akane; Tsutsumi, Kadzuyo; Morita, Hiroshi

2008-10-01

Aspergillus sp. N2 and Penicillium sp. N3 are chromate-resistant filamentous fungi that were isolated from Cr(VI) contaminated soil based on their ability to decrease hexavalent chromium levels in the growth medium. After 120 h of growth in a medium containing 50 ppm Cr(VI) at near neutral pH, Aspergillus sp. N2 reduced the Cr(VI) concentration by about 75%. Penicillium sp. N3 was able to reduce the Cr(VI) concentration by only 35%. However, Penicillium sp. N3 reduced the Cr(VI) concentration in the medium by 93% under acidic conditions. Interestingly, the presence of Cu(II) enhanced the Cr(VI) reducing ability of Aspergillus sp. N2 and Penicillium sp. N3 at near neutral pH. Aspergillus sp. N2 and Penicillium sp. N3 reduced the Cr(VI) concentration in the growth medium to a virtually undetectable level within 120 h. For both Aspergillus sp. N2 and Penicillium sp. N3, mycelial seed cultures were more efficient at Cr(VI) reduction than conidium seed cultures. The mechanisms of Cr(VI) reduction in Aspergillus sp. N2 and Penicillium sp. N3 were enzymatic reduction and sorption to mycelia. Enzymatic activity contributed significantly to Cr(VI) reduction. Aspergillus sp. N2 and Penicillium sp. N3 reduced the levels of Cr(VI) in polluted soil samples, suggesting that these strains might be useful for cleaning up chromium-contaminated sites.

The aquatic fern Azolla as a natural plant-factory for ammonia removal from fish-breeding fresh wastewater.

PubMed

Carlozzi, Pietro; Padovani, Giulia

2016-05-01

This study has investigated the potential of an Azolla-Anabaena symbiosis, a marriage between the cyanobacterium Anabaena azollae and the aquatic fern (Azolla), to remove ammonia from freshwater fish breeding areas. Experiments were carried out under artificial light of 20, 70, and 140 μmol m(-2) s(-1). We investigated three different water temperatures for the growing Azolla, ranging from sub-optimal to optimal temperatures (15, 22, and 28 °C). The capability of Azolla to remove ammonia from wastewater was demonstrated, and the highest ammonia concentration tolerated by the symbiosis between Azolla-anabaena without any toxic effect on the aquatic ferns was ascertained. The shortest time taken to remove ammonia from wastes, 2.5 cm deep and at 28 °C, was 40 min. The ammonia removal rate (A RR) was both light and temperature dependent and the highest rate (6.394 h(-1)) was attained at light intensity of 140 μmol m(-2) s(-1) and at a temperature of 28 °C; the lowest (0.947 h(-1)) was achieved at 20 μmol m(-2) s(-1) and 15 °C. The depth of the fish-wastewater pool also affected the A RR with the relation between A RR and the depth being a hyperbolic function.

Growth and cellular ion content of a salt-sensitive symbiotic system Azolla pinnata-Anabaena azollae under NaCl stress.

PubMed

Rai, Vandna; Sharma, Naveen Kumar; Rai, Ashwani K

2006-09-01

Salinity, at a concentration of 10 mM NaCl affected the growth of Azolla pinnata-Anabaena azollae association and became lethal at 40 mM. Plants exposed up to 30 mM NaCl exhibited longer roots than the control, especially during the beginning of incubation. Average root number in plants exposed to 10 and 20 mM NaCl remained almost the same as in control. A further rise in NaCl concentration to 30 mM reduced the root number, and roots shed off at 40 mM NaCl. Presence of NaCl in the nutrient solution increased the cellular Na+ of the intact association exhibiting differential accumulation by individual partners, while it reduced the cellular Ca2+ level. However, cellular K+ content did not show significant change. Cellular Na+ based on fresh weight of respective individual partners (host tissues and cyanobiont) remained higher in the host tissues than the cyanobiont, while reverse was true for K+ and Ca2+ contents. The contribution of A. azollae in the total cellular ion content of the association was a little because of meagre contribution of the cyanobiont mass (19-21%). High salt sensitivity of Azolla-Anabaena complex is due to an inability of the association to maintain low Na+ and high Ca2+ cellular level.

Interactions between amphibians' symbiotic bacteria cause the production of emergent anti-fungal metabolites

PubMed Central

Loudon, Andrew H.; Holland, Jessica A.; Umile, Thomas P.; Burzynski, Elizabeth A.; Minbiole, Kevin P. C.; Harris, Reid N.

2014-01-01

Amphibians possess beneficial skin bacteria that protect against the disease chytridiomycosis by producing secondary metabolites that inhibit the pathogen Batrachochytrium dendrobatidis (Bd). Metabolite production may be a mechanism of competition between bacterial species that results in host protection as a by-product. We expect that some co-cultures of bacterial species or strains will result in greater Bd inhibition than mono-cultures. To test this, we cultured four bacterial isolates (Bacillus sp., Janthinobacterium sp., Pseudomonas sp. and Chitinophaga arvensicola) from red-backed salamanders (Plethodon cinereus) and cultured isolates both alone and together to collect their cell-free supernatants (CFS). We challenged Bd with CFSs from four bacterial species in varying combinations. This resulted in three experimental treatments: (1) CFSs of single isolates; (2) combined CFSs of two isolates; and (3) CFSs from co-cultures. Pair-wise combinations of four bacterial isolates CFSs were assayed against Bd and revealed additive Bd inhibition in 42.2% of trials, synergistic inhibition in 42.2% and no effect in 16.6% of trials. When bacteria isolates were grown in co-cultures, complete Bd inhibition was generally observed, and synergistic inhibition occurred in four out of six trials. A metabolite profile of the most potent co-culture, Bacillus sp. and Chitinophaga arvensicola, was determined with LC-MS and compared with the profiles of each isolate in mono-culture. Emergent metabolites appearing in the co-culture were inhibitory to Bd, and the most potent inhibitor was identified as tryptophol. Thus mono-cultures of bacteria cultured from red-backed salamanders interacted synergistically and additively to inhibit Bd, and such bacteria produced emergent metabolites when cultured together, with even greater pathogen inhibition. Knowledge of how bacterial species interact to inhibit Bd can be used to select probiotics to provide amphibians with protection against Bd. PMID:25191317

Lipid production from tapioca wastewater by culture of Scenedesmus sp. with simultaneous BOD, COD and nitrogen removal

NASA Astrophysics Data System (ADS)

Romaidi; Hasanudin, Muhammad; Kholifah, Khusnul; Maulidiyah, Alik; Putro, Sapto P.; Kikuchi, Akira; Sakaguchi, Toshifumi

2018-05-01

The use of microalgae to produce biodiesel or possibly remove nutrients from industrial wastewater has gained important attention during recent years due to their photosynthetic rate and its versatile nature to grow in various wastewater systems. In this study, a microalgae, Scenedesmus sp., was cultured to enhance the lipid production and nutrients removal from tapioca wastewater sample. To assess lipid production, Scenedesmus sp. was cultured in different concentration of tapioca wastewater sample (from 0 to 100 %), and nutrient removal including BOD, COD, NH4, NO2, NO3 level by Scenedesmus sp. was assessed in 100% of tapioca wastewater culture. After 8 days of culture, it was found out that 50% of tapioca wastewater sample resulted in highest concentration of lipid content than that of the other concentrations. The level of environment indicator as nutrient removal such as BOD, COD, NH4, NO2, NO3 were also decreased up to 74%, 72%, 95%, 91%, and 91%, respectively. The pH condition changed from initial condition acidic (pH: 4) to neutral or basic condition (pH: 7-8) as recommended in wastewater treatment system. This research provided a novel approach and achieved efficient simultaneous lipid production and nutrients removal from tapioca wastewater sample by Scenedesmus’s culture system.

Culture of Daphnia sp. (crustacean – cladocera): the effect of manure variation on the growth, natality, and mortality

NASA Astrophysics Data System (ADS)

Herman, H.; Andriani, Y.; Sahidin, A.; Hidayat, T.; Herawati, T.

2018-04-01

The objective of this research was to analyze the growth rate, reproduction rate, and mortality rate of Daphnia sp. which cultured in variant organic manure. This research used experimental method Randomized Completely Block Design (RCBD) with four treatment and three replications. The treatments in this research were the variant manures from chicken, quail, goat, and cow with same of growth (2,4 g/l). Daphnia cultured with using 100 breeders since from neonets (0 day) until growth up and died in one life cycle. At the 3-days, culture of Daphnia sp was give peak population with maximum age of culture using quail manure is 7 days, and other treatments are 8 days. The growth rate and the reproduction rate of using quail manure was higher than using chicken manure, goat manure, and cow manure (mean GR = 3.68 : 2.32 : 2.74 : 2.97; mean RR = 3.87 : 2.59 : 3.00 : 3.31; p < 0,05). Although all the breeders of Daphnia sp. died at 8th day of culture, quail manure give the lowest of mortality rate than using chicken manure, goat manure, and cow manure (mean MR = 0.19 : 0.28 : 0.26 : 0.34).

Air-dust-borne associations of phototrophic and hydrocarbon-utilizing microorganisms: promising consortia in volatile hydrocarbon bioremediation.

PubMed

Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

2012-11-01

Aquatic and terrestrial associations of phototrophic and heterotrophic microorganisms active in hydrocarbon bioremediation have been described earlier. The question arises: do similar consortia also occur in the atmosphere? Dust samples at the height of 15 m were collected from Kuwait City air, and analyzed microbiologically for phototrophic and heterotrophic hydrocarbon-utilizing microorganisms, which were subsequently characterized according to their 16S rRNA gene sequences. The hydrocarbon utilization potential of the heterotrophs alone, and in association with the phototrophic partners, was measured quantitatively. The chlorophyte Gloeotila sp. and the two cyanobacteria Nostoc commune and Leptolyngbya thermalis were found associated with dust, and (for comparison) the cynobacteria Leptolyngbya sp. and Acaryochloris sp. were isolated from coastal water. All phototrophic cultures harbored oil vapor-utilizing bacteria in the magnitude of 10(5) g(-1). Each phototrophic culture had its unique oil-utilizing bacteria; however, the bacterial composition in Leptolyngbya cultures from air and water was similar. The hydrocarbon-utilizing bacteria were affiliated with Acinetobacter sp., Aeromonas caviae, Alcanivorax jadensis, Bacillus asahii, Bacillus pumilus, Marinobacter aquaeolei, Paenibacillus sp., and Stenotrophomonas maltophilia. The nonaxenic cultures, when used as inocula in batch cultures, attenuated crude oil in light and dark, and in the presence of antibiotics and absence of nitrogenous compounds. Aqueous and diethyl ether extracts from the phototrophic cultures enhanced the growth of the pertinent oil-utilizing bacteria in batch cultures, with oil vapor as a sole carbon source. It was concluded that the airborne microbial associations may be effective in bioremediating atmospheric hydrocarbon pollutants in situ. Like the aquatic and terrestrial habitats, the atmosphere contains dust-borne associations of phototrophic and heterotrophic hydrocarbon-utilizing bacteria that are active in hydrocarbon attenuation.

[Effects of continuous application of bio-organic fertilizer on banana production and cultural microflora of bulk soil in orchard with serious disease incidence].

PubMed

Zhong, Shu-tang; Shen, Zong-zhuan; Sun, Yi-fei; Lyu, Na-na; Ruan, Yun-ze; Li, Rong; Shen, Qi-rong

2015-02-01

A field experiment was conducted for two years to investigate the effects of different fertilization applications on the suppression of banana fusarium wilt disease, crop yield, fruit quality and culturable microflora in a banana orchard which has been monocultured with banana for 12 years and suffered serious banana fusarium wilt disease. The fertilizers included chemical fertilizer (CF), cow manure compost (CM), pig manure compost (PM) and bio-organic fertilizer (BIO). The banana soil microflora was invested using plate-counting method and culture-dependent polymerase chain reaction denaturing gradient gel electrophoresis method (CD PCR-DGGE). Results showed that, compared with the other treatments, 2-year consecutive application of BIO significantly reduced the banana fusarium wilt disease incidence, and improved the banana mass per tree, crop yield, total soluble sugar content and the ratio of total soluble sugar to titratable acidity of fruits (sugar/acid ratio). Moreover, the analysis of culturable microflora showed that BIO application significantly increased the soil microbial biomass, soil culturable bacteria, bacillus and actinomycetes, and the ratio of bacteria to fungi (B/F) , while decreased the Fusarium oxysporum. Based on the CD PCR-DGGE results, the BIO application significantly altered the soil culturable bacterial structure and showed highest richness and diversity after 2 years of BIO application. The phylogenetic analysis of the selected bands showed that BIO application enriched the soil with the species of Paenibacillus sp., Burkholderia sp., uncultured Verrucomicrobia sp. and Bacillus aryabhattai, and depressed the species of Ralstonia sp., Chryseobacterium gleum, Fluviicola taffensis, Enterobacter sp. and Bacillus megaterium. These results confirmed that the continuous application of BIO effectively controlled the fusarium wilt disease, improved the crop yield and fruit quality, and modulated the soil culturable microflora under field condition.

Bacterial diversity associated with the rotifer Brachionus plicatilis sp. complex determined by culture-dependent and -independent methods.

PubMed

Ishino, Ryota; Iehata, Shunpei; Nakano, Miyo; Tanaka, Reiji; Yoshimatsu, Takao; Maeda, Hiroto

2012-03-01

The bacterial communities associated with rotifers (Brachionus plicatilis sp. complex) and their culture water were determined using culture-dependent and -independent methods (16S rRNA gene clone library). The bacterial communities determined by the culture-independent method were more diverse than those determined by the culture-dependent method. Although the culture-dependent method indicated the bacterial community of rotifers was relatively similar to that of the culture water, 16S rRNA gene clone library analyses revealed a great difference between the two microbiotas. Our results suggest that most bacteria associated with rotifers are not easily cultured using conventional methods, and that the microbiota of rotifers do not correspond with that of the culture water completely.

Cyanobacterial diversity in extreme environments in Baja California, Mexico: a polyphasic study.

PubMed

López-Cortés, A; García-Pichel, F; Nübel, U; Vázquez-Juárez, R

2001-12-01

Cyanobacterial diversity from two geographical areas of Baja California Sur, Mexico, were studied: Bahia Concepcion, and Ensenada de Aripez. The sites included hypersaline ecosystems, sea bottom, hydrothermal springs, and a shrimp farm. In this report we describe four new morphotypes, two are marine epilithic from Bahia Concepcion, Dermocarpa sp. and Hyella sp. The third, Geitlerinema sp., occurs in thermal springs and in shrimp ponds, and the fourth, Tychonema sp., is from a shrimp pond. The partial sequences of the 16S rRNA genes and the phylogenetic relationship of four cyanobacterial strains (Synechococcus cf. elongatus, Leptolyngbya cf. thermalis, Leptolyngbya sp., and Geitlerinema sp.) are also presented. Polyphasic studies that include the combination of light microscopy, cultures and the comparative analysis of 16S rRNA gene sequences provide the most powerful approach currently available to establish the diversity of these oxygenic photosynthetic microorganisms in culture and in nature.

A rapid analysis of water for anatoxin a, the unstable toxic alkaloid from Anabaena flos-aquae, the stable non-toxic alkaloids left after bioreduction and a related amine which may be nature's precursor to anatoxin a.

PubMed

Smith, R A; Lewis, D

1987-04-01

Poisoning of animals by Anabaena Flos-Aquae alkaloid is a common, but sporadic event (1). Anatoxin A is the toxic principle responsible for acute fatalities (2), and tends to disappear along with the toxicity within a few days of the event, thus complicating diagnosis. This report reveals our simplified analytical methodology for Anatoxin A (2-acetyl-9-azabicyclo[4.2.1] non-2,3-ene), for the non-toxic compounds into which it bioreduces, the chair and boat forms of 2-acetyl-9-azabicyclo[4.2.1] nonane, and for an as yet uncharacterized amine C10H15N.

Changes in symbiotic and associative interrelations in a higher plant-bacterial system during space flight

NASA Astrophysics Data System (ADS)

Kordyum, V. A.; Man'ko, V. G.; Popova, A. F.; Shcherbak, O. H.; Mashinsky, A. L.; Nguen-Hgue-Thyok

The miniature cenosis consisting of the water fern Azolla with its associated symbiotic nitrogen-fixing cyanobacterium Anabaena and the concomitant bacteria was investigated. Ecological closure was shown to produce sharp quantitative and qualitative changes in the number and type of concomitant bacteria. Changes in the distribution of bacterial types grown on beef-extract broth after space flight were recorded. Anabaena azollae underwent the most significant changes under spaceflight conditions. Its cell number per Azolla biomass unit increased substantially. Thus closure of cenosis resulted in a weakening of control over microbial development by Azolla. This tendency was augmented by spaceflight factors. Reduction in control exerted by macro-organisms over development of associated micro-organisms must be taken into account in constructing closed ecological systems in the state of weightlessness.

An overview of diversity, occurrence, genetics and toxin production of bloom-forming Dolichospermum (Anabaena) species.

PubMed

Li, Xiaochuang; Dreher, Theo W; Li, Renhui

2016-04-01

The new genus name Dolichospermum, for most of the planktonic former members of the genus Anabaena, is one of the most ubiquitous bloom-forming cyanobacterial genera. Its dominance and persistence have increased in recent years, due to eutrophication from anthropogenic activities and global climate change. Blooms of Dolichospermum species, with their production of secondary metabolites that commonly include toxins, present a worldwide threat to environmental and public health. In this review, recent advances of the genus Dolichospermum are summarized, including taxonomy, genetics, bloom occurrence, and production of toxin and taste-and-odor compounds. The recent and continuing acquisition of genome sequences is ushering in new methods for monitoring and understanding the factors regulating bloom dynamics. Copyright © 2015 Elsevier B.V. All rights reserved.

A role for the diazotrophic cyanobacterium, Cyanothece sp. strain ATCC 51142, in nitrogen cycling for CELSS applications.

PubMed

Schneegurt, M A; Sherman, L A

1996-01-01

Simple calculations show that fixed nitrogen regeneration in a CELSS may not be as efficient as stowage and resupply of fixed nitrogen compounds. However, fixed nitrogen regeneration may be important for the sustainability and safety of a deployed CELSS. Cyanothece sp. strain ATCC 51142, a unicellular, aerobic, diazotrophic cyanobacterium, with high growth rates and a robust metabolism, is a reasonable candidate organism for a biological, fixed nitrogen regeneration system. In addition, Cyanothece sp. cultures may be used to balance gas exchange ratio imparities between plants and humans. The regeneration of fixed nitrogen compounds by cyanobacterial cultures was examined in the context of a broad computer model/simulation (called CELSS-3D). When cyanothece sp. cultures were used to balance gas exchange imparities, the biomass harvested could supply as much as half of the total fixed nitrogen needed for plant biomass production.

Repertoire of free-living protozoa in contact lens solutions.

PubMed

Bouchoucha, Ibtissem; Aziz, Aurore; Hoffart, Louis; Drancourt, Michel

2016-10-29

The repertoire of free-living protozoa in contact lens solutions is poorly known despite the fact that such protozoa may act as direct pathogens and may harbor intra-cellular pathogens. Between 2009 and 2014, the contact lens solutions collected from patients presenting at our Ophthalmology Department for clinically suspected keratitis, were cultured on non-nutrient agar examined by microscope for the presence of free-living protozoa. All protozoa were identified by 18S rRNA gene sequencing. A total of 20 of 233 (8.6 %) contact lens solution specimens collected from 16 patients were cultured. Acanthamoeba amoeba in 16 solutions (80 %) collected from 12 patients and Colpoda steini, Cercozoa sp., Protostelium sp. and a eukaryotic more closely related to Vermamoeba sp., were each isolated in one solution. Cercozoa sp., Colpoda sp., Protostelium sp. and Vermamoeba sp. are reported for the first time as contaminating contact lens solutions. The repertoire of protozoa in contact lens solutions is larger than previously known.

Characterization of side population in thyroid cancer cell lines: cancer stem-like cells are enriched partly but not exclusively.

PubMed

Mitsutake, Norisato; Iwao, Atsuhiko; Nagai, Kazuhiro; Namba, Hiroyuki; Ohtsuru, Akira; Saenko, Vladimir; Yamashita, Shunichi

2007-04-01

There is increasing evidence that cancers contain their own stem-like cells called cancer stem cells (CSCs). A small subset of cells, termed side population (SP), has been identified using flow cytometric analysis. The SP cells have the ability to exclude the DNA binding dye, Hoechst33342, and are highly enriched for stem cells in many kinds of normal tissues. Because CSCs are thought to be drug resistant, SP cells in cancers might contain CSCs. We initially examined the presence of SP cells in several human thyroid cancer cell lines. A small percentage of SP cells were found in ARO (0.25%), FRO (0.1%), NPA (0.06%), and WRO (0.02%) cells but not TPC1 cells. After sorting, the SP cells generated both SP and non-SP cells in culture. The clonogenic ability of SP cells was significantly higher than that of non-SP cells. Moreover, the SP prevalence was dependent on cell density in culture, suggesting that SP cells preferentially survived at lower cell density. Microarray experiment revealed differential gene expression profile between SP and non-SP cells, and several genes related to stemness were up-regulated. However, non-SP population also contained cells that were tumorigenic in nude mice, and non-SP cells generated a small number of SP cells. These results suggest that cancer stem-like cells are partly, but not exclusively, enriched in SP population. Clarifying the key tumorigenic population might contribute to the establishment of a novel therapy for thyroid cancer.

The combined effects of UV-B radiation and herbicides on photosynthesis, antioxidant enzymes and DNA damage in two bloom-forming cyanobacteria.

PubMed

Chen, Lanzhou; Xie, Mu; Bi, Yonghong; Wang, Gaohong; Deng, Songqiang; Liu, Yongding

2012-06-01

In this study, we investigated the combined effects of UV-B irradiation and herbicides (glyphosate, GPS; 2-Methyl-4-chlorophenoxyacetic acid, MCPA-Na; 3-(3,4-dichlorophenyl)-1,1-dimethylurea, DCMU) and the antioxidant (ascorbic acid, ASC) on photosynthesis, antioxidant enzymes and DNA damage in two bloom-forming cyanobacteria, Anabaena sp. and Microcystis viridis. UV-B irradiance increased reactive oxygen species (ROS) production, which decreased chlorophyll a fluorescence yield, pigment content and superoxide dismutase (SOD) activity, and increased malondialdehyde (MDA) content and caused serious DNA damage. The degree of these damages was aggravated by the addition of DCMU, GPS and MCPA, and was partially mitigated by the addition of ASC. During the recovery process, the degree and mechanism in restoring DNA damage and photosynthesis inhibition were different by the removal of UV-B and herbicides (DCMU, GPS and MCPA) in both cyanobacteria. These results suggest that the combination of UV-B and exogenous herbicides have detrimental effects on cyanobacterial metabolism through either a ROS-mediated process or by affecting the electron transport chain, and may cause the shifts in the phytoplankton community. Copyright © 2012 Elsevier Inc. All rights reserved.

Stable coexistence of five bacterial strains as a cellulose-degrading community.

PubMed

Kato, Souichiro; Haruta, Shin; Cui, Zong Jun; Ishii, Masaharu; Igarashi, Yasuo

2005-11-01

A cellulose-degrading defined mixed culture (designated SF356) consisting of five bacterial strains (Clostridium straminisolvens CSK1, Clostridium sp. strain FG4, Pseudoxanthomonas sp. strain M1-3, Brevibacillus sp. strain M1-5, and Bordetella sp. strain M1-6) exhibited both functional and structural stability; namely, no change in cellulose-degrading efficiency was observed, and all members stably coexisted through 20 subcultures. In order to investigate the mechanisms responsible for the observed stability, "knockout communities" in which one of the members was eliminated from SF356 were constructed. The dynamics of the community structure and the cellulose degradation profiles of these mixed cultures were determined in order to evaluate the roles played by each eliminated member in situ and its impact on the other members of the community. Integration of each result gave the following estimates of the bacterial relationships. Synergistic relationships between an anaerobic cellulolytic bacterium (C. straminisolvens CSK1) and two strains of aerobic bacteria (Pseudoxanthomonas sp. strain M1-3 and Brevibacillus sp. strain M1-5) were observed; the aerobes introduced anaerobic conditions, and C. straminisolvens CSK1 supplied metabolites (acetate and glucose). In addition, there were negative relationships, such as the inhibition of cellulose degradation by producing excess amounts of acetic acid by Clostridium sp. strain FG4, and growth suppression of Bordetella sp. strain M1-6 by Brevibacillus sp. strain M1-5. The balance of the various types of relationships (both positive and negative) is thus considered to be essential for the stable coexistence of the members of this mixed culture.

Comparison of Thraustochytrids Aurantiochytrium sp., Schizochytrium sp., Thraustochytrium sp., and Ulkenia sp. for production of biodiesel, long-chain omega-3 oils, and exopolysaccharide.

PubMed

Lee Chang, Kim Jye; Nichols, Carol Mancuso; Blackburn, Susan I; Dunstan, Graeme A; Koutoulis, Anthony; Nichols, Peter D

2014-08-01

Heterotrophic growth of thraustochytrids has potential in coproducing biodiesel for transportation, as well as producing a feedstock for omega-3 long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA), especially docosahexaenoic acid (DHA) for use in nutraceuticals. In this study, we compared eight new endemic Australian thraustochytrid strains from the genera Aurantiochytrium, Schizochytrium, Thraustochytrium, and Ulkenia for the synthesis of exopolysaccharide (EPS), in addition to biodiesel and LC-PUFA. Aurantiochytrium sp. strains readily utilized glucose for biomass production, and increasing glucose from 2 to 4 % w/v of the culture medium resulted in increased biomass yield by an average factor of 1.7. Ulkenia sp. strain TC 010 and Thraustochytrium sp. strain TC 033 did not utilize glucose, while Schizochytrium sp. strain TC 002 utilized less than half the glucose available by day 14, and Thraustochytrium sp. strain TC 004 utilized glucose at 4 % w/v but not 2 % w/v of the culture suggesting a threshold requirement between these values. Across all strains, increasing glucose from 2 to 4 % w/v of the culture medium resulted in increased total fatty acid methyl ester content by an average factor of 1.9. Despite an increasing literature demonstrating the capacity of thraustochytrids for DHA synthesis, the production of EPS from these organisms is not well documented. A broad range of EPS yields was observed. The maximum yield of EPS was observed for Schizochytrium sp. strain TC 002 (299 mg/L). High biomass-producing strains that also have high lipid and high EPS yield may be better candidates for commercial production of biofuels and other coproducts.

Francisella marina sp. nov., etiologic agent of systemic disease in cultured spotted rose snapper (Lutjanus guttatus) in Central America

USDA-ARS?s Scientific Manuscript database

Historically, piscine francisellosis in various warm, temperate and coldwater fish hosts has been attributed to Francisella noatunensis. From 2015-2016, an undescribed Francisella sp. was recovered during mortality events in cultured spotted rose snapper (Lutjanus guttatus) off the Pacific coast of ...

Dichloromethane Fermentation by a Dehalobacter sp. in an Enrichment Culture Derived from Pristine River Sediment

PubMed Central

Justicia-Leon, Shandra D.; Ritalahti, Kirsti M.; Mack, E. Erin

2012-01-01

Dichloromethane (DCM) as the sole substrate supported growth of a Dehalobacter sp. in an enrichment culture derived from noncontaminated river sediment. DCM was not reductively dechlorinated, and acetate was produced, indicating DCM fermentation and further suggesting Dehalobacter growth is not limited to organohalide respiration. PMID:22179245

Cyanobacteria reduce quagga mussel (Dreissena rostriformis bugensis) spawning and fertilization success

USGS Publications Warehouse

Boegehold, Anna G; Johnson, Nicholas; Ran, Jeffrey L; Kashian, Donna R

2018-01-01

exposure to cyanobacteria can inhibit quagga mussel spawning and fertilization. We assessed spawning in the presence of serotonin, a known spawning inducer, where adult quagga mussels placed in individual vials were exposed to 13 cyanobacteria cultures and purified algal toxin (microcystin-LR) with artificial lake water as the control. Fertilization success was evaluated by combining eggs with sperm in conjunction with cyanobacteria, and enumerating zygote formation marked by cellular cleavage. Several cyanobacterial strains reduced spawning and fertilization success, but microcystin-LR had no effect. Fertilization was more sensitive to cyanobacteria than gamete release. Only 1 culture, Aphanizomenon flos-aquae, inhibited spawning, whereas 6 cultures consisting of Anabaena flos-aquae, Dolichospermum lemmermanii, Gloeotrichia echinulata, Lyngbya wollei, and 2 Microcystis aeruginosa isolates reduced fertilization rates by up to 44%. The effects of cyanobacteria on reproduction in invasive freshwater mussels in the wild have not yet been identified. However, our laboratory studies show that concentrations of cyanobacteria that are possible during bloom conditions probably limit reproduction. Reproductive consequences on wild populations may become more prevalent as cyanobacteria blooms occur earlier in the year, making overlap between blooms and mussel spawning more common. Describing the mechanism by which cyanobacteria inhibit spawning and fertilization could reveal novel control methods to limit reproduction of this invasive species.

Characterization of two subsurface H2-utilizing bacteria, Desulfomicrobium hypogeium sp. nov. and Acetobacterium psammolithicum sp. nov., and their ecological roles.

PubMed

Krumholz, L R; Harris, S H; Tay, S T; Suflita, J M

1999-06-01

We examined the relative roles of acetogenic and sulfate-reducing bacteria in H2 consumption in a previously characterized subsurface sandstone ecosystem. Enrichment cultures originally inoculated with ground sandstone material obtained from a Cretaceous formation in central New Mexico were grown with hydrogen in a mineral medium supplemented with 0.02% yeast extract. Sulfate reduction and acetogenesis occurred in these cultures, and the two most abundant organisms carrying out the reactions were isolated. Based on 16S rRNA analysis data and on substrate utilization patterns, these organisms were named Desulfomicrobium hypogeium sp. nov. and Acetobacterium psammolithicum sp. nov. The steady-state H2 concentrations measured in sandstone-sediment slurries (threshold concentration, 5 nM), in pure cultures of sulfate reducers (threshold concentration, 2 nM), and in pure cultures of acetogens (threshold concentrations 195 to 414 nM) suggest that sulfate reduction is the dominant terminal electron-accepting process in the ecosystem examined. In an experiment in which direct competition for H2 between D. hypogeium and A. psammolithicum was examined, sulfate reduction was the dominant process.

ACANTHAMOEBA SP.S-11 PHAGOCYTOTIC ACTIVITY ON MYCOBACTERIUM LEPRAE IN DIFFERENT NUTRIENT CONDITIONS.

PubMed

Paling, Sepling; Wahyuni, Ratna; Ni'matuzahroh; Winarni, Dwi; Iswahyudi; Astari, Linda; Adriaty, Dinar; Agusni, Indropo; Izumi, Shinzo

2018-01-01

Mycobacterium leprae ( M. leprae ) is a pathogenic bacterium that causes leprosy. The presence of M. leprae in the environment is supported by microorganisms that act as the new host for M. leprae . Acanthamoeba 's potential to be a host of M. leprae in the environment. Acanthamoeba sp. is Free Living Amoeba (FLA) that classified as holozoic, saprophytic, and saprozoic. The existence of nutrients in the environment influence Acanthamoeba ability to phagocytosis or pinocytosis. This study is aimed to determine Acanthamoeba sp.S-11 phagocytic activity to Mycobacterium leprae ( M. leprae ) which cultured in non-nutrient media and riched-nutrient media. This research conducted by culturing Acanthamoeba sp.S-11 and M. leprae on different nutrient media conditions. M. leprae intracellular DNA were isolated and amplified by M. leprae specific primers through Real Time PCR (Q-PCR). The results showed that Acanthamoeba co-cultured on non-nutrient media were more active to phagocyte M. leprae than on rich-nutrient media. The use of non-nutrient media is recommended to optimize Acanthamoeba sp. phagocytic activity to M. leprae .

Growth and enzymological characteristics of a pink-pigmented facultative methylotroph Methylobacterium sp. MB1.

PubMed

Baev, M V; Kuznetsov, E V; Skladnev, D A; Govorukhina, N I; Sterkin, V E; Tsygankov, Y D

1992-01-01

Growth characteristics of batch and continuous cultures of the pink facultative methylotroph Methylobacterium sp. MB1 were determined. The response of a chemostat culture to a pulse increase of methanol concentration was studied. Malate, succinate and oxaloacetate additions to the methanol-supplemented medium decreased batch culture growth inhibition by methanol. The carotenoid content in cells grown in a chemostat decreased with increasing growth rate. The key enzyme activities of C1-metabolism were measured in a chemostat culture at different dilution rates.

Unusual Versatility of the Filamentous, Diazotrophic Cyanobacterium Anabaena torulosa Revealed for Its Survival during Prolonged Uranium Exposure

PubMed Central

Chandwadkar, Pallavi; Nayak, Chandrani

2017-01-01

ABSTRACT Reports on interactions between cyanobacteria and uranyl carbonate are rare. Here, we present an interesting succession of the metabolic responses employed by a marine, filamentous, diazotrophic cyanobacterium, Anabaena torulosa for its survival following prolonged exposure to uranyl carbonate extending up to 384 h at pH 7.8 under phosphate-limited conditions. The cells sequestered uranium (U) within polyphosphates on initial exposure to 100 μM uranyl carbonate for 24 to 28 h. Further incubation until 120 h resulted in (i) significant degradation of cellular polyphosphates causing extensive chlorosis and cell lysis, (ii) akinete differentiation followed by (iii) extracellular uranyl precipitation. X-ray diffraction (XRD) analysis, fluorescence spectroscopy, X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) spectroscopy established the identity of the bioprecipitated uranium as a U(VI) autunite-type mineral, which settled at the bottom of the vessel. Surprisingly, A. torulosa cells resurfaced as small green flakes typical of actively growing colonies on top of the test solutions within 192 to 240 h of U exposure. A consolidated investigation using kinetics, microscopy, and physiological and biochemical analyses suggested a role of inducible alkaline phosphatase activity of cell aggregates/akinetes in facilitating the germination of akinetes leading to substantial regeneration of A. torulosa by 384 h of uranyl incubation. The biomineralized uranium appeared to be stable following cell regeneration. Altogether, our results reveal novel insights into the survival mechanism adopted by A. torulosa to resist sustained uranium toxicity under phosphate-limited oxic conditions. IMPORTANCE Long-term effects of uranyl exposure in cyanobacteria under oxic phosphate-limited conditions have been inadequately explored. We conducted a comprehensive examination of the metabolic responses displayed by a marine cyanobacterium, Anabaena torulosa, to cope with prolonged exposure to uranyl carbonate at pH 7.8 under phosphate limitation. Our results highlight distinct adaptive mechanisms harbored by this cyanobacterium that enabled its natural regeneration following extensive cell lysis and uranium biomineralization under sustained uranium exposure. Such complex interactions between environmental microbes such as Anabaena torulosa and uranium over a broader time range advance our understanding on the impact of microbial processes on uranium biogeochemistry. PMID:28258135

Isolation of marine fungi Aspergillus sp. and its in vitro antifouling activity against marine bacteria.

PubMed

Thiyagarajan, Santhananmari; Bavya, Manoharan; Jamal, Alruwaili

2016-09-01

Biofouling is considered as a main issue of concern in aquatic environment causing severe economic loss and pollution. The aim of the present study was to isolate marine fungus antagonistic to biofouling bacteria and to define antifouling compounds present in it. Using standard plate method five predominant biofouling bacteria viz., Methylococcus sp., Flavobacterium sp., Marinococcus sp., Serratia sp. and Pseudomonas sp. were isolated from marine solid substances on Zobell's agar. Tolerance range of these bacteria to NaCl was 2-10%. Isolation of fungi from mangrove and estuarine sediments and their screening identified Aspergillus sp. EF4 as a potential isolate. This isolate caused inhibition of all the five test bacterial cultures measuring zone diameters respectively of 11, 16, 12, 13 and 11mm.? Subsequent to submerged fermentation using shaking flask method this fungus produced bioactive compounds within 5 days. The culture parameters optimized were raffinose as carbon source, yeast extract as lone nitrogen source, pH up to 9.0 and temperature up to 40?C. Antifouling compounds of culture filtrate were separated and detected by a three-step procedure involving thin layer chromatography, bioautography and preparative TLC. The in vitro assay involving glass slide-wooden stick-biofilm method revealed that these compounds could cause inhibition and destruction of bacteria to an extent of 2.16 x 104 CFU ml-1 and 2.46 x 104 CFU ml-1 respectively while growth of bacteria in control beaker was enumerated to be 4.41 x 104 CFU ml-1. High performance liquid chromatography of culture filtrate indicated probable principal antifouling compound as Fumonisin B2. Isolation of antagonistic marine fungus from Indian coast and detection of its antifouling compound would help in planning effective strategies for controlling biofouling in marine environment.

Failure Analysis of Pitted Copper Pipes Used in Underground Water and Preventive Measures

NASA Astrophysics Data System (ADS)

Nam, Gi-ho; Lee, Jong-kwon; Kim, Kyung-ja

2018-05-01

This study performed an experiment on the causes of pitting corrosion in a copper tubing used for a sprinkler system. Corrosion products of a copper tubing that sustained pitting corrosion were collected and cultured in Culture medium [Luria-Bertani, Brain heart infusion, Tryptic soy broth (TSB), R2A]. Four types of bacteria were found through identification: Micrococcus luteus sp (species)., Staphylococcus sp., Sphingomonas sp., and Bacillus sp. The copper toxicity test was performed for each microorganism. Among the four microorganisms, Micrococcus luteus sp. showed good growth in the environment containing copper ions. On the immersion test, changes in pH and Optical density were measured; On the inductively coupled plasma optical emission spectrometry test, the copper concentration of each culture medium was measured. The surface of each copper sample was observed using a scanning electron microscope. The corrosion potential of a copper sample, after 48 h exposure of the TSB medium containing Micrococcus luteus sp., was measured using a potentiodynamic polarization experiment. The next experiment was conducted to prevent microbial corrosion by suppressing the growth of microorganisms. Six 30 ml TSB culture media with controlled pH value of 4, 5, 6, 7, 8, and 9 through HCl and NaOH were manufactured. Then the microorganisms were cultured in 37 °C 133 rpm, of which the growth status was checked every 24 h for 3 days. It was found that microorganisms did not grow on culture media with the pH value of 6 and lower. The same experiment conducted on culture media controlled with acetic acid, nitric acid, and sulfuric acid, also showed no growth of microorganisms on media with pH value of 6 and lower. Six 5 ml TSB culture media each containing 0.5, 0.25, 0.125, 0.0625, 0.0312%, and 0.0156% NaOCl and NaOBr as germicides were manufactured. 0.01 μl of microorganisms were inoculated on the media and cultured in 37 °C for 48 h. It was found that microorganisms did not grow in media with NaOCl and NaOBr concentration of 0.0625% and higher. Therefore, it can be suggested that in environments with pH value of 6 or lower, or NaOCl and NaOBr concentration of higher than 0.0625% suppresses microbial growth, thereby preventing microbial corrosion.

Failure Analysis of Pitted Copper Pipes Used in Underground Water and Preventive Measures

NASA Astrophysics Data System (ADS)

Nam, Gi-ho; Lee, Jong-kwon; Kim, Kyung-ja

2018-03-01

This study performed an experiment on the causes of pitting corrosion in a copper tubing used for a sprinkler system. Corrosion products of a copper tubing that sustained pitting corrosion were collected and cultured in Culture medium [Luria-Bertani, Brain heart infusion, Tryptic soy broth (TSB), R2A]. Four types of bacteria were found through identification: Micrococcus luteus sp (species)., Staphylococcus sp., Sphingomonas sp., and Bacillus sp. The copper toxicity test was performed for each microorganism. Among the four microorganisms, Micrococcus luteus sp. showed good growth in the environment containing copper ions. On the immersion test, changes in pH and Optical density were measured; On the inductively coupled plasma optical emission spectrometry test, the copper concentration of each culture medium was measured. The surface of each copper sample was observed using a scanning electron microscope. The corrosion potential of a copper sample, after 48 h exposure of the TSB medium containing Micrococcus luteus sp., was measured using a potentiodynamic polarization experiment. The next experiment was conducted to prevent microbial corrosion by suppressing the growth of microorganisms. Six 30 ml TSB culture media with controlled pH value of 4, 5, 6, 7, 8, and 9 through HCl and NaOH were manufactured. Then the microorganisms were cultured in 37 °C 133 rpm, of which the growth status was checked every 24 h for 3 days. It was found that microorganisms did not grow on culture media with the pH value of 6 and lower. The same experiment conducted on culture media controlled with acetic acid, nitric acid, and sulfuric acid, also showed no growth of microorganisms on media with pH value of 6 and lower. Six 5 ml TSB culture media each containing 0.5, 0.25, 0.125, 0.0625, 0.0312%, and 0.0156% NaOCl and NaOBr as germicides were manufactured. 0.01 μl of microorganisms were inoculated on the media and cultured in 37 °C for 48 h. It was found that microorganisms did not grow in media with NaOCl and NaOBr concentration of 0.0625% and higher. Therefore, it can be suggested that in environments with pH value of 6 or lower, or NaOCl and NaOBr concentration of higher than 0.0625% suppresses microbial growth, thereby preventing microbial corrosion.

Effects of Bacterial Community Members on the Proteome of the Ammonia-Oxidizing Bacterium Nitrosomonas sp. Strain Is79.

PubMed

Sedlacek, Christopher J; Nielsen, Susanne; Greis, Kenneth D; Haffey, Wendy D; Revsbech, Niels Peter; Ticak, Tomislav; Laanbroek, Hendrikus J; Bollmann, Annette

2016-08-01

Microorganisms in the environment do not exist as the often-studied pure cultures but as members of complex microbial communities. Characterizing the interactions within microbial communities is essential to understand their function in both natural and engineered environments. In this study, we investigated how the presence of a nitrite-oxidizing bacterium (NOB) and heterotrophic bacteria affect the growth and proteome of the chemolithoautotrophic ammonia-oxidizing bacterium (AOB) Nitrosomonas sp. strain Is79. We investigated Nitrosomonas sp. Is79 in co-culture with Nitrobacter winogradskyi, in co-cultures with selected heterotrophic bacteria, and as a member of the nitrifying enrichment culture G5-7. In batch culture, N. winogradskyi and heterotrophic bacteria had positive effects on the growth of Nitrosomonas sp. Is79. An isobaric tag for relative and absolute quantification (iTRAQ) liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach was used to investigate the effect of N. winogradskyi and the co-cultured heterotrophic bacteria from G5-7 on the proteome of Nitrosomonas sp. Is79. In co-culture with N. winogradskyi, several Nitrosomonas sp. Is79 oxidative stress response proteins changed in abundance, with periplasmic proteins increasing and cytoplasmic proteins decreasing in abundance. In the presence of heterotrophic bacteria, the abundance of proteins directly related to the ammonia oxidation pathway increased, while the abundance of proteins related to amino acid synthesis and metabolism decreased. In summary, the proteome of Nitrosomonas sp. Is79 was differentially influenced by the presence of either N. winogradskyi or heterotrophic bacteria. Together, N. winogradskyi and heterotrophic bacteria reduced the oxidative stress for Nitrosomonas sp. Is79, which resulted in more efficient metabolism. Aerobic ammonia-oxidizing microorganisms play an important role in the global nitrogen cycle, converting ammonia to nitrite. In their natural environment, they coexist and interact with nitrite oxidizers, which convert nitrite to nitrate, and with heterotrophic microorganisms. The presence of nitrite oxidizers and heterotrophic bacteria has a positive influence on the growth of the ammonia oxidizers. Here, we present a study investigating the effect of nitrite oxidizers and heterotrophic bacteria on the proteome of a selected ammonia oxidizer in a defined culture to elucidate how these two groups improve the performance of the ammonia oxidizer. The results show that the presence of a nitrite oxidizer and heterotrophic bacteria reduced the stress for the ammonia oxidizer and resulted in more efficient energy generation. This study contributes to our understanding of microbe-microbe interactions, in particular between ammonia oxidizers and their neighboring microbial community. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Isolation of AHL-degrading bacteria from micro-algal cultures and their impact on algal growth and on virulence of Vibrio campbellii to prawn larvae.

PubMed

Pande, Gde Sasmita Julyantoro; Natrah, Fatin Mohd Ikhsan; Flandez, Ace Vincent Bravo; Kumar, Uday; Niu, Yufeng; Bossier, Peter; Defoirdt, Tom

2015-12-01

Inactivation of quorum sensing (QS) signal molecules, such as acylhomoserine lactones (AHLs) of pathogenic bacteria, has been proposed as a novel method to combat bacterial diseases in aquaculture. Despite the importance of micro-algae for aquaculture, AHL degradation by bacteria associated with micro-algal cultures has thus far not been investigated. In this study, we isolated Pseudomonas sp. NFMI-T and Bacillus sp. NFMI-C from open cultures of the micro-algae Tetraselmis suecica and Chaetoceros muelleri, respectively. An AHL degradation assay showed that either monocultures or co-cultures of the isolates were able to degrade the AHL N-hexanoyl-L-homoserine lactone. In contrast, only Bacillus sp. NFMI-C was able to inactivate N-hydroxybutanoyl-L-homoserine lactone, the AHL produced by Vibrio campbellii. The isolated bacteria were able to persist for up to 3 weeks in conventionalized micro-algal cultures, indicating that they were able to establish and maintain themselves within open algal cultures. Using gnotobiotic algal cultures, we found that the isolates did not affect growth of the micro-algae from which they were isolated, whereas a mixture of both isolates increased the growth of Tetraselmis and decreased the growth of Chaetoceros. Finally, addition of Bacillus sp. NFMI-C to the rearing water of giant river prawn (Macrobrachium rosenbergii) larvae significantly improved survival of the larvae when challenged with pathogenic V. campbellii, whereas it had no effect on larval growth.

Diagnostic utility of melanin production by fungi: study on tissue sections and culture smears with Masson-Fontana stain.

PubMed

Sundaram, Challa; Shantveer, G Uppin; Umabala, Pamidi; Lakshmi, Vemu

2014-01-01

Dematiaceous fungi appear brown in tissue section due to melanin in their cell walls. When the brown color is not seen on routine H and E and culture is not available, differentiation of dematiaceous fungi from other fungi is difficult on morphology alone. To study if melanin production by dematiaceous fungi can help differentiate them from other types of fungi. Fifty tissue sections of various fungal infections and 13 smears from cultures of different species of fungi were stained with Masson Fontana stain to assess melanin production. The tissue sections included biopsies from 26 culture-proven fungi and 24 biopsies of filamentous fungi diagnosed on morphology alone with no culture confirmation. All culture-proven dematiaceous fungi and Zygomycetes showed strong positivity in sections and culture smears. Aspergillus sp showed variable positivity and intensity. Cryptococcus neoformans showed strong positivity in tissue sections and culture smears. Tissue sections of septate filamentous fungi (9/15), Zygomycetes (4/5), and fungi with both hyphal and yeast morphology (4/4) showed positivity for melanin. The septate filamentous fungi negative for melanin were from biopsy samples of fungal sinusitis including both allergic and invasive fungal sinusitis and colonizing fungal balls. Melanin is produced by both dematiaceous and non-dematiaceous fungi. Masson-Fontana stain cannot reliably differentiate dematiaceous fungi from other filamentous fungi like Aspergillus sp; however, absence of melanin in the hyphae may be used to rule out dematiaceous fungi from other filamentous fungi. In the differential diagnosis of yeast fungi, Cryptococcus sp can be differentiated from Candida sp by Masson-Fontana stain in tissue sections.

Draft Genome Sequence of Muricauda sp. Strain K001 Isolated from a Marine Cyanobacterial Culture.

PubMed

Vizzotto, Carla S; Lopes, Fabyano A C; Green, Stefan J; Steindorff, Andrei S; Walter, Juline M; Thompson, Fabiano L; Krüger, Ricardo H

2018-05-31

We report the whole-genome sequence of Muricauda sp. strain K001 isolated from a marine cyanobacterial culture. This genome sequence will improve our understanding of the influence of heterotrophic bacteria on the physiology of cyanobacteria and may contribute to the development of new natural products. Copyright © 2018 Vizzotto et al.

Culture medium optimization for acetic acid production by a persimmon vinegar-derived bacterium.

PubMed

Kim, Jin-Nam; Choo, Jong-Sok; Wee, Young-Jung; Yun, Jong-Sun; Ryu, Hwa-Won

2005-01-01

A new acetic acid-producing microorganism, Acetobacter sp. RKY4, was isolated from Korean traditional persimmon vinegar, and we optimized the culture medium for acetic acid production from ethanol using the newly isolated Acetobacter sp. RKY4. The optimized culture medium for acetic acid production using this microorganism was found to be 40 g/L ethanol, 10 g/L glycerol, 10 g/L corn steep liquor, 0.5 g/L MgSO4.7H2O, and 1.0 g/L (NH4)H2PO4. Acetobacter sp. RKY4 produced 47.1 g/L of acetic acid after 48 h of fermentation in a 250 mL Erlenmeyer flask containing 50 mL of the optimized medium.

Biodegradation of gamma-hexachlorocyclohexane (lindane) and alpha-hexachlorocyclohexane in water and a soil slurry by a Pandoraea species.

PubMed

Okeke, Benedict C; Siddique, Tariq; Arbestain, Marta Camps; Frankenberger, William T

2002-04-24

Isomers of 1,2,3,4,5,6-hexachlorocyclohexane (HCH) were some of the most widely used pesticides. Despite reduction in their production and use, HCH isomers present a serious environmental hazard. In this study, two bacterial isolates (LIN-1 and LIN-3) that can grow on gamma-HCH as a sole source of carbon and energy were isolated from an enrichment culture. In liquid cultures of LIN-1 and LIN-3, 25.0 and 45.5% removal of gamma-HCH, respectively, were achieved in 2 weeks. LIN-3 was identified as Pandoraea sp. by 16S rRNA gene sequence analysis (99% identity). Pandoraea sp. substantially degraded both gamma- and alpha-HCH isomers at concentrations of 10-200 mg L(-1) in liquid cultures. After 8 weeks of incubation in liquid culture, 89.9 and 93.3% of the gamma- and alpha-HCH isomers declined, respectively, at an initial concentration of 150 mg L(-1). In soil slurry cultures of Pandoraea sp., simulating a soil slurry phase bioremediation treatment, substantial decreases in the levels of the HCH isomers were observed at concentrations of 50-200 mg L(-1). After 9 weeks, 59.6 and 53.3% biodegradations of gamma- and alpha-HCH isomers, respectively, were achieved at 150 mg L(-1). Using two 23-mer oligonucloetide primers targeting the 330 bp region of the 16S rRNA gene of Pandoraea sp., an approximately 330 bp PCR product was successfully amplified from DNA templates prepared from bacterial colonies and soil slurry culture. This system provides a direct and rapid PCR-based molecular tool for tracking Pandoraea sp. strain LIN-3 in water and soils. These results have implied implications for the treatment of soils and water contaminated with HCH isomers.

Substance P enhances proliferation and paracrine potential of adipose-derived stem cells in vitro.

PubMed

Kim, Suna; Piao, Jiyuan; Son, Youngsook; Hong, Hyun Sook

2017-03-25

Stem cells have tremendous promise to treat intractable diseases. Notably, adipose-derived stem cells (ADSCs) are actively being investigated because of ease of sampling and high repopulation capacity in vitro. ADSCs can exert a therapeutic effect through differentiation and paracrine potential, and these actions have been proven in many diseases, including cutaneous and inflammatory diseases. Transplantation of ADSCs necessitates therapeutic quantities and thus, long term ex vivo culture of ADSCs. However, this procedure can impair the activity of ADSCs and provoke cellular senescence, leading to low efficacy in vivo. Accordingly, strategies to restore cellular activity and inhibit senescence of stem cells during ex vivo culture are needed for stem cell-based therapies. This study evaluated a potential supplementary role of Substance P (SP) in ADSC ex vivo culture. After confirming that the ADSC cell cycle was damaged by passage 6 (p6), ADSCs at p6 were cultured with SP, and their proliferation rates, cumulative cell numbers, cytokine profiles, and impact on T/endothelial cells were assessed. Long-term culture weakened proliferation ability and secretion of the cytokines, transforming growth factor-beta 1 (TGF-beta1), vascular endothelial growth factor (VEGF), and stromal cell derived factor-1 alpha (SDF-1alpha) in ADSCs. However, SP treatment reduced the population doubling time (PDT), enabling gain of a sufficient number of ADSCs at early passages. In addition, SP restored cytokine secretion, enhancing the ADSC-mediated paracrine effect on T cell and human umbilical vein endothelial cells (HUVECs). Taken together, these results suggest that SP can retain the therapeutic effect of ADSCs by elevating their proliferative and paracrine potential in ex vivo culture. Copyright © 2017 Elsevier Inc. All rights reserved.

Cultural Resources Survey and Testing Along Ditch 19 and Extensive Testing of 23DU289, Dunklin and Stoddard Counties, Missouri.

DTIC Science & Technology

1988-06-30

Carya illinoensis ) 1 1 Persimmon (Diospyros virginiana) T 2 2 Pl.um (Prunus sp.) T Red Haw (Crataegus sp.) T 1 11 Red Mulberry (Morus rubra) T...2 Cherry (Prunus sp.) T Cottonwood (Populus sp.) 1 3 Dogwood (Cornus sp.) 1 Hackberry (Celtus occidentalis) 12 9 Hickory, ( Carya sp.) 5 4 Shellhark... Carya laciniosa) T Hornbeam (Ostrya virginiana) 2 Kentucky Coffee Tree( Gymnoeladus dioica)T Locust, T Black (Robinia pseudo-acacia) T Honey

Isolation and characterization of a marine algicidal bacterium against the harmful raphidophyceae Chattonella marina.

PubMed

Kim, Yun Sook; Lee, Dae-Sung; Jeong, Seong-Yun; Lee, Woe Jae; Lee, Myung-Suk

2009-02-01

A bacterial strain named AB-4 showing algicidal activity against Chattonella marina was isolated from coastal water of ULjin, Republic of Korea. The isolated strain was identified as Bacillus sp. by culture morphology, biochemical reactions, and homology research based on 16S rDNA. The bacterial culture led to the lysis of algal cells, suggesting that the isolated strain produced a latent algal-lytic compound. Amongst changes in algicidal activity by different culture filtrate volumes, the 10% (100 microl/ml) concentration showed the biggest change in algicidal activity; there, estimated algicidal activity was 95%. The swimming movements of Chattonella marina cells were inhibited because of treatment of the bacterial culture; subsequently, Chattonella marina cells became swollen and rounded. With longer exposure time, algal cells were disrupted and cellular components lost their integrity and decomposed. The released algicide(s) were heat-tolerant and stable in pH variations, except pH 3, 4, and 5. Culture filtrate of Bacillus sp. AB-4 was toxic against harmful algae bloom (HAB) species and nontoxic against livefood organisms. Bacillus sp. AB-4 showed comparatively strong activity against Akashiwo sanguinea, Fibriocapsa japonica, Heterosigma akashiwo, and Scrippsiella trochoidea. These results suggest that the algicidal activity of Bacillus sp. AB-4 is potentially useful for controlling outbreaks of Chattonella marina.

Production of Gouda cheese and Camembert with probiotic cultures: the suitability of some commercial probiotic cultures to be implemented in cheese.

PubMed

Van de Casteele, S; Ruyssen, T; Vanheuverzwijn, T; Van Assche, P

2003-01-01

The behaviour of 10 probiotic cultures (L. acidophilus, Bifidobacterium sp., L. rhamnosus and L. paracasei) was examined during the production and ripening of Gouda cheese and Camembert. The overall objective of this research project was to obtain a product (cheese) containing at least 10(7) probiotic cfu/g. In general 10(6) cfu of a probiotic culture must be implemented per ml cheese milk, together with the cheesestarter, to reach this objective. L. paracasei sp. have the ability to grow more than 2 log units during cheese ripening. A lower inoculation value can be considered for these cultures.

The effect of temperature on the sensitivity of Daphnia magna to cyanobacteria is genus dependent.

PubMed

Hochmuth, Jennifer D; De Schamphelaere, Karel A C

2014-10-01

In the present study, the authors investigated the effects of 6 different genera of cyanobacteria on multiple endpoints of Daphnia magna in a 21-d life table experiment conducted at 3 different temperatures (15 °C, 19 °C, and 23 °C). The specific aims were to test if the effect of temperature on Daphnia's sensitivity to cyanobacteria differed among different cyanobacteria and if the rank order from most to least harmful cyanobacteria to Daphnia reproduction changed or remained the same across the studied temperature range. Overall, the authors observed a decrease in harmful effects on reproduction with increasing temperature for Microcystis, Nodularia, and Aphanizomenon, and an increase in harmful effects with increasing temperature for Anabaena and Oscillatoria. No effect of temperature was observed on Daphnia sensitivity to Cylindrospermopsis. Harmful effects of Microcystis and Nodularia on reproduction appear to be mirrored by a decrease in length. On the other hand, harmful effects of Anabaena, Aphanizomenon, and Oscillatoria on reproduction were correlated with a decrease in intrinsic rate of natural increase, which was matched by a later onset of reproduction in exposures to Oscillatoria. In addition, the results suggest that the cyanobacteria rank order of harmfulness may change with temperature. Higher temperatures may increase the sensitivity of D. magna to the presence of some cyanobacteria (Anabaena and Oscillatoria) in their diet, whereas the harmful effects of others (Microcystis, Nodularia, and Aphanizomenon) may be reduced by higher temperatures. © 2014 SETAC.

Time-dependent growth of crystalline Au(0)-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica.

PubMed

Rösken, Liz M; Cappel, Felix; Körsten, Susanne; Fischer, Christian B; Schönleber, Andreas; van Smaalen, Sander; Geimer, Stefan; Beresko, Christian; Ankerhold, Georg; Wehner, Stefan

2016-01-01

Microbial biosynthesis of metal nanoparticles as needed in catalysis has shown its theoretical ability as an extremely environmentally friendly production method in the last few years, even though the separation of the nanoparticles is challenging. Biosynthesis, summing up biosorption and bioreduction of diluted metal ions to zero valent metals, is especially ecofriendly, when the bioreactor itself is harmless and needs no further harmful reagents. The cyanobacterium Anabaena cylindrica (SAG 1403.2) is able to form crystalline Au(0)-nanoparticles from Au(3+) ions and does not release toxic anatoxin-a. X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and laser-induced breakdown spectroscopy (LIBS) are applied to monitor the time-dependent development of gold nanoparticles for up to 40 hours. Some vegetative cells (VC) are filled with nanoparticles within minutes, while the extracellular polymeric substances (EPS) of vegetative cells and the heterocyst polysaccharide layer (HEP) are the regions, where the first nanoparticles are detected on most other cells. The uptake of gold starts immediately after incubation and within four hours the average size remains constant around 10 nm. Analyzing the TEM images with an image processing program reveals a wide distribution for the diameter of the nanoparticles at all times and in all regions of the cyanobacteria. Finally, the nanoparticle concentration in vegetative cells of Anabaena cylindrica is about 50% higher than in heterocysts (HC). These nanoparticles are found to be located along the thylakoid membranes.

The LysR-type transcription factor PacR is a global regulator of photosynthetic carbon assimilation in Anabaena.

PubMed

Picossi, Silvia; Flores, Enrique; Herrero, Antonia

2015-09-01

Cyanobacteria perform water-splitting photosynthesis and are important primary producers impacting the carbon and nitrogen cycles at global scale. They fix CO2 through ribulose-bisphosphate carboxylase/oxygenase (RuBisCo) and have evolved a distinct CO2 concentrating mechanism (CCM) that builds high CO2 concentrations in the vicinity of RuBisCo favouring its carboxylase activity. Filamentous cyanobacteria such as Anabaena fix CO2 in photosynthetic vegetative cells, which donate photosynthate to heterocysts that rely on a heterotrophic metabolism to fix N2 . CCM elements are induced in response to inorganic carbon limitation, a cue that exposes the photosynthetic apparatus to photodamage by over-reduction. An Anabaena mutant lacking the LysR-type transcription factor All3953 grew poorly and dies under high light. The rbcL operon encoding RuBisCo was induced upon carbon limitation in the wild type but not in the mutant. ChIP-Seq analysis was used to globally identify All3953 targets under carbon limitation. Targets include, besides rbcL, genes encoding CCM elements, photorespiratory pathway- photosystem- and electron transport-related components, and factors, including flavodiiron proteins, with a demonstrated or putative function in photoprotection. Quantitative reverse transcription polymerase chain reaction analysis of selected All3953 targets showed regulation in the wild type but not in the mutant. All3953 (PacR) is a global regulator of carbon assimilation in an oxygenic photoautotroph. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

A Salt-Inducible Mn-Catalase (KatB) Protects Cyanobacterium from Oxidative Stress.

PubMed

Chakravarty, Dhiman; Banerjee, Manisha; Bihani, Subhash C; Ballal, Anand

2016-02-01

Catalases, enzymes that detoxify H2O2, are widely distributed in all phyla, including cyanobacteria. Unlike the heme-containing catalases, the physiological roles of Mn-catalases remain inadequately characterized. In the cyanobacterium Anabaena, pretreatment of cells with NaCl resulted in unusually enhanced tolerance to oxidative stress. On exposure to H2O2, the NaCl-treated Anabaena showed reduced formation of reactive oxygen species, peroxides, and oxidized proteins than the control cells (i.e. not treated with NaCl) exposed to H2O2. This protective effect correlated well with the substantial increase in production of KatB, a Mn-catalase. Addition of NaCl did not safeguard the katB mutant from H2O2, suggesting that KatB was indeed responsible for detoxifying the externally added H2O2. Moreover, Anabaena deficient in KatB was susceptible to oxidative effects of salinity stress. The katB gene was strongly induced in response to osmotic stress or desiccation. Promoter-gfp analysis showed katB to be expressed only in the vegetative cells but not in heterocysts. Biochemically, KatB was an efficient, robust catalase that remained active in the presence of high concentrations of NaCl. Our findings unravel the role of Mn-catalase in acclimatization to salt/oxidative stress and demonstrate that the oxidative stress resistance of an organism can be enhanced by a simple compound such as NaCl. © 2016 American Society of Plant Biologists. All Rights Reserved.

Photophosphorylation capacity of stable spheroplast preparations of anabaena.

PubMed

Spiller, H

1980-09-01

Spheroplasts from Anabaena 7119 (formerly designated Nostoc muscorum) were prepared in the presence of serum albumin in 0.5 molar sucrose. Electron transport and photophosphorylation were preserved (> 70% of the maximum rate for 1 week). The pH profile of electron transport and photophosphorylation in the reactions H(2)O --> NADP, H(2)O --> methyl viologen, and H(2)O --> ferricyanide shows that uncoupling by ammonia is small throughout and increases slightly with higher pH. ADP + Pi increased NADP reduction from H(2)O by 2.5-fold. The ratios of ATP formed per electron pair transported ranged from 0.9 to 1.5. Effects of catalase and superoxide dismutase on the overall O(2) balance implicate pseudocyclic electron transport and phosphorylation. The quenching of 9-aminoacridine fluorescence indicates the formation of a Delta pH from 2 to 2.6 during illumination. This pH gradient is abolished by uncouplers; however, complete uncoupling is achieved only by 3-chlorocarbonyl cyanide phenylhydrazone or valinomycin + NH(4) (+). In the presence of NH(4) (+) alone, the membrane potential may act as the driving force for photophosphorylation.Increasing amounts of bovine serum albumin protected phosphorylation from uncoupling by silicomolybdic acid. 3-(3,4-Dichlorophenyl)-1, 1-dimethylurea-insensitive water oxidation by silicomolybdic acid provides evidence that the site for 3-(3,4-dichlorophenyl)-1, 1-dimethylurea action is on the acceptor and not donor side of photosystem II in the procaryote Anabaena. It is concluded that stable spheroplasts retain coupled electron transport approaching in vivo rates.

The sRNA NsiR4 is involved in nitrogen assimilation control in cyanobacteria by targeting glutamine synthetase inactivating factor IF7.

PubMed

Klähn, Stephan; Schaal, Christoph; Georg, Jens; Baumgartner, Desirée; Knippen, Gernot; Hagemann, Martin; Muro-Pastor, Alicia M; Hess, Wolfgang R

2015-11-10

Glutamine synthetase (GS), a key enzyme in biological nitrogen assimilation, is regulated in multiple ways in response to varying nitrogen sources and levels. Here we show a small regulatory RNA, NsiR4 (nitrogen stress-induced RNA 4), which plays an important role in the regulation of GS in cyanobacteria. NsiR4 expression in the unicellular Synechocystis sp. PCC 6803 and in the filamentous, nitrogen-fixing Anabaena sp. PCC 7120 is stimulated through nitrogen limitation via NtcA, the global transcriptional regulator of genes involved in nitrogen metabolism. NsiR4 is widely conserved throughout the cyanobacterial phylum, suggesting a conserved function. In silico target prediction, transcriptome profiling on pulse overexpression, and site-directed mutagenesis experiments using a heterologous reporter system showed that NsiR4 interacts with the 5'UTR of gifA mRNA, which encodes glutamine synthetase inactivating factor (IF)7. In Synechocystis, we observed an inverse relationship between the levels of NsiR4 and the accumulation of IF7 in vivo. This NsiR4-dependent modulation of gifA (IF7) mRNA accumulation influenced the glutamine pool and thus [Formula: see text] assimilation via GS. As a second target, we identified ssr1528, a hitherto uncharacterized nitrogen-regulated gene. Competition experiments between WT and an ΔnsiR4 KO mutant showed that the lack of NsiR4 led to decreased acclimation capabilities of Synechocystis toward oscillating nitrogen levels. These results suggest a role for NsiR4 in the regulation of nitrogen metabolism in cyanobacteria, especially for the adaptation to rapid changes in available nitrogen sources and concentrations. NsiR4 is, to our knowledge, the first identified bacterial sRNA regulating the primary assimilation of a macronutrient.

Optimization of cyanophycin production in recombinant strains of Pseudomonas putida and Ralstonia eutropha employing elementary mode analysis and statistical experimental design.

PubMed

Diniz, Simone Cardoso; Voss, Ingo; Steinbüchel, Alexander

2006-03-05

Elementary mode analysis was applied to simulate conditions for cyanophycin (CGP) biosynthesis and to optimize its production in bacteria. The conclusions from these simulations were confirmed by experiments with recombinant strains of the wild types and polyhydroxyalkanoate (PHA)-negative mutants of Ralstonia eutropha and Pseudomonas putida expressing CGP synthetase genes (cphA) of Synechocystis sp. strain PCC6308 or Anabaena sp. strain PCC7120. In particular, the effects of suitable precursor substrates and of oxygen supply as well as of the capability to accumulate PHA in addition to CGP biosynthesis were investigated. Since CGP consists of the amino acids aspartate and arginine, the tricarboxylic acid cycle (TCC), which provides intermediates for biosynthesis of these amino acids, seems to be important. Excretion of intermediates of the TCC upon cultivation at restricted oxygen supply and conversion of fumarate mainly to malate and to only little succinate in the absence of oxygen indicated that TCC intermediates for arginine and aspartate biosynthesis were provided by the oxidative or reductive parts of the TCC, respectively. The following important conclusions were made from the experiments and the simulations: (i) external arginine additionally supplied to the medium, (ii) oxygen limitation, and (iii) absence of PHA accumulation exerted positive effects on CGP accumulation. These conclusions were utilized to obtain CGP contents in the cells of as high as 17.9% (w x w(-1)) during cultivation of the investigated bacteria at the 30-L scale using mineral salts medium. Such high CGP contents were previously not obtained with these bacteria at a 30-L scale, even if complex media were used.

Anatoxin-a and its metabolites in blue-green algae food supplements from Canada and Portugal.

PubMed

Rawn, Dorothea F K; Niedzwiadek, Barbara; Lau, Benjamin P Y; Saker, Martin

2007-03-01

Blue-green algae and spirulina are marketed in health food stores and over the Internet as food supplements in Canada, the United States, and Europe. The reported benefits of consuming these products include improved digestion, strengthening of the immune system, and relief from the symptoms of attention deficit disorder. Some of these products have been found to contain elevated concentrations of microcystins, which are known hepatotoxins. In addition to producing microcystins, Anabaena sp. and Aphanizomenon sp. also produce the potent neurotoxin anatoxin-a. Samples of food supplements containing blue-green algae and spirulina were collected in Portugal and from urban centers across Canada in 2005. Extracts of these supplements were analyzed to determine the presence and concentrations of anatoxin-a and its two main metabolites, dihydroanatoxin-a and epoxyanatoxin-a. Initial analyses were performed using high-performance liquid chromatography (HPLC) with fluorescence detection, and confirmation required the use of LC with tandem mass spectrometry (LC-MS-MS). The HPLC with fluorescence detection indicated no anatoxin-a, but four samples were suspected to contain either dihydroanatoxin-a or epoxyanatoxin-a at 0.1 to 0.2 microg/g. LC-MS-MS results, however, indicated no trace of either transformation product in any sample analyzed. The detection limits for anatoxin-a, dihydroanatoxin-a, and epoxyanatoxin-a were similar for both fluorescence detection (0.2 to 0.3, 0.4 to 1.4, and 0.2 to 1.5 pg on the column, respectively) and mass spectrometry (0.3 to 1.5, 0.3 to 0.8, and 0.5 to 0.8 pg on the column, respectively). Because of the higher specificity of the LC-MS-MS analysis, all tested food supplement samples were considered free of anatoxin-a and its transformation products.

Translational control of small heat shock genes in mesophilic and thermophilic cyanobacteria by RNA thermometers

PubMed Central

Cimdins, Annika; Klinkert, Birgit; Aschke-Sonnenborn, Ursula; Kaiser, Friederike M; Kortmann, Jens; Narberhaus, Franz

2014-01-01

Cyanobacteria constitute a heterogeneous phylum of oxygen-producing, photosynthetic prokaryotes. They are susceptible to various stress conditions like heat, salt, or light stress, all inducing the cyanobacterial heat shock response (HSR). Cyanobacterial small heat shock proteins (sHsps) are known to preserve thylakoid membrane integrity under stress conditions, thereby protecting the photosynthesis machinery. In Synechocystis sp PCC 6803, synthesis of the sHsp Hsp17 is regulated by an RNA thermometer (RNAT) in the 5′-untranslated region (5′-UTR) of the hsp17 mRNA. RNATs are direct temperature sensors that control expression of many bacterial heat shock and virulence genes. They hinder translation at low temperatures by base pairing, thus blocking ribosome access to the mRNA.   To explore the temperature range in which RNATs act, we studied various RNAT candidates upstream of sHsp genes from mesophilic and thermophilic cyanobacteria. The mesophilic cyanobacteria Anabaena variabilis and Nostoc sp chromosomally encode two sHsps each. Reporter gene studies suggested RNAT-mediated post-transcriptional regulation of shsp expression in both organisms. Detailed structural analysis of the two A. variabilis candidates revealed two novel RNAT types. The first, avashort, regulates translation primarily by masking of the AUG translational start codon. The second, featuring an extended initial hairpin, thus named avalong, presumably makes use of complex tertiary interaction. The 5′-UTR of the small heat shock gene hspA in the thermophile Thermosynechococcus elongatus is predicted to adopt an extended secondary structure. Structure probing revealed that the ribosome binding site was blocked at temperatures below 55 °C. The results of this study demonstrate that cyanobacteria commonly use RNATs to control expression of their small heat shock genes. PMID:24755616

Strategy for improving extracellular lipolytic activities by a novel thermotolerant Staphylococcus sp. strain

PubMed Central

2011-01-01

Background Extracellular bacterial lipases received much attention for their substrate specificity and their ability to function under extreme environments (pH, temperature...). Many staphylococci produced lipases which were released into the culture medium. Reports of extracellular thermostable lipases from Staphylococcus sp. and active in alkaline conditions are not previously described. Results This study focused on novel strategies to increase extracellular lipolytic enzyme production by a novel Staphylococcus sp. strain ESW. The microorganism needed neutral or alkaline pH values between 7.0 and 12.0 for growth. For pH values outside this range, cell growth seemed to be significantly inhibited. Staphylococcus sp. culture was able to grow within a wide temperature range (from 30 to 55°C). The presence of oils in the culture medium leaded to improvements in cells growth and lipolytic enzyme activity. On the other hand, although chemical surfactants leaded to an almost complete inhibition of growth and lipolytic enzyme production, their addition along the culture could affect the location of the enzyme. In addition, our results showed that this novel Staphylococcus sp. strain produced biosurfactants simultaneously with lipolytic activity, when soapstock (The main co-product of the vegetable oil refining industry), was used as the sole carbon source. Conclusion A simultaneous biosurfactant and extracellular lipolytic enzymes produced bacterial strain with potential application in soap stock treatment PMID:22078466

Use of secondary-treated wastewater for the production of Muriellopsis sp.

PubMed

Gómez, C; Escudero, R; Morales, M M; Figueroa, F L; Fernández-Sevilla, J M; Acién, F G

2013-03-01

In this paper, the use of secondary-treated wastewater as the culture medium for the production of Muriellopsis sp. microalgal biomass is analyzed. Using this wastewater, a maximum biomass productivity of 0.5 g l(-1) day(-1) was measured, it being only 38 % lower than that achieved using the standard culture medium. Due to the low nitrogen content of secondary-treated wastewater, cultures produced in a medium containing a high percentage of it become nitrate-limited, thus the quantum yield reduces by up to 0.38 g E(-1)--this compares to 0.67 g E(-1) when using a standard culture medium. On the other hand, nitrate limitation enhances the accumulation of lipids and carbohydrates, with values measured at 33 and 66 % dry weight, respectively. It was also demonstrated that secondary-treated wastewater does not have any toxic effect on the growth of Muriellopsis sp. in spite of nitrogen being in the form of ammonium rather than in nitrate. Moreover, the secondary-treated wastewater was depurated when used to produce Muriellopsis sp., with the outlet biological oxygen demand and chemical oxygen demand being lower than at the inlet; the nitrate and phosphate concentrations were zero. Therefore, Muriellopsis sp. production using secondary-treated wastewater allows a reduction in the process cost by decreasing freshwater and fertilizer use, as well as by depurating the water, thus greatly enhancing process sustainability.

RNA polymerase gene, microorganism having said gene and the production of RNA polymerase by the use of said microorganism

DOEpatents

Kotani, Hirokazu; Hiraoka, Nobutsugu; Obayashi, Akira

1991-01-01

SP6 bacteriophage RNA polymerase is produced by cultivating a new microorganism (particularly new strains of Escherichia coli) harboring a plasmid that carries SP6 bacteriophage RNA polymerase gene and recovering SP6 bacteriophage RNA polymerase from the culture broth. SP6 bacteriophage RNA polymerase gene is provided as are new microorganisms harboring a plasmid that carries SP6 bacteriophage RNA polymerase gene.

Substance P induced preprotachykinin-a mRNA, neutral endopeptidase mRNA and substance P in cultured normal fibroblasts.

PubMed

Bae, Sang-Jae; Matsunaga, Yoshitaka; Takenaka, Motoi; Tanaka, Yoichi; Hamazaki, Yoichiro; Shimizu, Kazuhiro; Katayama, Ichiro

2002-04-01

In certain skin diseases, stress can modulate the induction and/or progression of cutaneous manifestations. However, little is known about the circuit in neuroendocrine and in the immune systems of the skin. To address this question, we have analyzed the regulatory mechanisms of autocrine induction of substance P (SP) by cultured normal human fibroblasts that compose the major population of the skin and might augment stress-induced skin inflammatory responses. In nonstimulated conditions, normal fibroblasts express a moderate amount of preprotachykinin-A (PPT-A), a precursor of SP mRNA, and exogenous SP significantly upregulated PPT-A mRNA expression. Maximum response of SP peptide and SP mRNA in fibroblasts was observed 1-3 h after stimulation with SP. In contrast, the expression of neutral endopeptidase (NEP), a cell surface peptide with hydrolyzing activity of SP, was increased in fibroblasts stimulated with SP after 24 h. The administration of NEP inhibitor (phosphoramidon) to the fibroblasts induced higher SP production. In addition, the neurokinin (NK) receptor antagonists (spantide, FK224 and FK888) and protein synthesis inhibitor (cycloheximide) inhibited SP production by 30-40% of control response. In immunostaining study, specific cytoplasmic staining of SP was observed in fibroblasts stimulated with SP. Finally, we confirmed that the nucleotide sequence of the PPT-A expressed in fibroblasts perfectly corresponded to the gene bank human PPT-A cDNA. This is the first report that SP mRNA, NEP mRNA and SP peptide can be induced by normal human skin fibroblasts in response to exogenous SP, and that fibroblast-derived SP might play an important role in the induction and acceleration of certain cutaneous diseases. Copyright 2002 S. Karger AG, Basel

Parasites infecting the cultured oyster Crassostrea gasar (Adanson, 1757) in Northeast Brazil.

PubMed

Queiroga, Fernando Ramos; Vianna, Rogério Tubino; Vieira, Cairé Barreto; Farias, Natanael Dantas; Da Silva, Patricia Mirella

2015-05-01

The oyster Crassostrea gasar is a species widely used as food and a source of income for the local population of the estuaries of Northeast Brazil. Perkinsus marinus and Perkinsus olseni are deleterious parasites for oyster farming and were recently detected in Brazil. In this study, a histopathologic survey of the oyster C. gasar cultured in the estuary of the River Mamanguape (Paraíba State) was performed. Adult oysters were collected in December 2011 and March, May, August and October 2012 and processed for histology and Perkinsus sp. identification by molecular analyses. Histopathological analysis revealed the presence of parasitic organisms including viral gametocytic hypertrophy, prokaryote-like colonies, protozoans (Perkinsus sp. and Nematopsis sp.) and metazoans (Tylocephalum sp. and cestodes). Other commensal organisms were also detected (the protozoan Ancistrocoma sp. and the turbellarian Urastoma sp.). The protozoan parasite Perkinsus sp. had the highest overall prevalence among the symbiotic organisms studied (48.9%), followed by Nematopsis sp. (36.3%). The other organisms were only sporadically observed. Only the protozoan Perkinsus sp. caused alterations in the oysters' infected organs. Molecular analyses confirmed the presence of P. marinus, P. olseni and Perkinsus beihaiensis infecting the oyster C. gasar. This is the first report of P. beihaiensis in this oyster species.

Effect of inorganic fertilizer on the growth of freshwater Chlorella sp.

NASA Astrophysics Data System (ADS)

Rahardini, R. A.; Helmiati, S.; Triyatmo, B.

2018-03-01

One of the alternative nutrient sources in the culture of Chlorella sp. is inorganic fertilizer. The aim of this study was to determine the effect of inorganic fertilizer composition in the culture medium on the growth of Chlorella sp. This research was conducted by using the 2.5 L transparent containers containing 2 L freshwater. The culture was carried out in laboratory facilitated with an air conditioner, fluorescent light and continuous aeration for 14 days of culture. The treatments consisted of fertilizer composition of Urea:ZA:TSP i.e. P1 (1:1:0,50), P2 (2:2:0,70), P3 (3:3:1), P4 (4:4:1,25) and P0 (Walne medium) as a positive control. Each treatment was performed in triplicates and arranged based on the Completely Randomized Design. Chlorella sp. was inoculated with the initial density of 30 × 104 cells·mL-1. The results of this study showed that the inorganic fertilizer composition of 3:3:1 provided the highest growth rate of 25.9 %/day, and the highest population density reached 2.348 × 104 cells·mL-1. The doubling time was not affected by the inorganic fertilizer treatments.

Characterization of Two Subsurface H2-Utilizing Bacteria, Desulfomicrobium hypogeium sp. nov. and Acetobacterium psammolithicum sp. nov., and Their Ecological Roles

PubMed Central

Krumholz, Lee R.; Harris, Steve H.; Tay, Stephen T.; Suflita, Joseph M.

1999-01-01

We examined the relative roles of acetogenic and sulfate-reducing bacteria in H2 consumption in a previously characterized subsurface sandstone ecosystem. Enrichment cultures originally inoculated with ground sandstone material obtained from a Cretaceous formation in central New Mexico were grown with hydrogen in a mineral medium supplemented with 0.02% yeast extract. Sulfate reduction and acetogenesis occurred in these cultures, and the two most abundant organisms carrying out the reactions were isolated. Based on 16S rRNA analysis data and on substrate utilization patterns, these organisms were named Desulfomicrobium hypogeium sp. nov. and Acetobacterium psammolithicum sp. nov. The steady-state H2 concentrations measured in sandstone-sediment slurries (threshold concentration, 5 nM), in pure cultures of sulfate reducers (threshold concentration, 2 nM), and in pure cultures of acetogens (threshold concentrations 195 to 414 nM) suggest that sulfate reduction is the dominant terminal electron-accepting process in the ecosystem examined. In an experiment in which direct competition for H2 between D. hypogeium and A. psammolithicum was examined, sulfate reduction was the dominant process. PMID:10347005

Up-regulation of lymphocyte antigen 6 complex expression in side-population cells derived from a human trophoblast cell line HTR-8/SVneo.

PubMed

Inagaki, Tetsunori; Kusunoki, Soshi; Tabu, Kouichi; Okabe, Hitomi; Yamada, Izumi; Taga, Tetsuya; Matsumoto, Akemi; Makino, Shintaro; Takeda, Satoru; Kato, Kiyoko

2016-01-01

The continual proliferation and differentiation of trophoblasts are critical for the maintenance of pregnancy. It is well known that the tissue stem cells are associated with the development of tissues and pathologies. It has been demonstrated that side-population (SP) cells identified by fluorescence-activated cell sorting (FACS) are enriched with stem cells. The SP cells in HTR-8/SVneo cells derived from human primary trophoblast cells were isolated by FACS. HTR-8/SVneo-SP cell cultures generated both SP and non-SP (NSP) subpopulations. In contrast, NSP cell cultures produced NSP cells and failed to produce SP cells. These SP cells showed self-renewal capability by serial colony-forming assay. Microarray expression analysis using a set of HTR-8/SVneo-SP and -NSP cells revealed that SP cells overexpressed several stemness genes including caudal type homeobox2 (CDX2) and bone morphogenic proteins (BMPs), and lymphocyte antigen 6 complex locus D (LY6D) gene was the most highly up-regulated in HTR-8/SVneo-SP cells. LY6D gene reduced its expression in the course of a 7-day cultivation in differentiation medium. SP cells tended to reduce its fraction by treatment of LY6D siRNA indicating that LY6D had potential to maintain cell proliferation of HTR-8/SVneo-SP cells. On ontology analysis, epithelial-mesenchymal transition (EMT) pathway was involved in the up-regulated genes on microarray analysis. HTR-SVneo-SP cells showed enhanced migration. This is the first report that LY6D was important for the maintenance of HTR-8/SVneo-SP cells. EMT was associated with the phenotype of these SP cells.

Purification and some properties of Fe protein of nitrogenase from. Anabaena cylindrica

NASA Astrophysics Data System (ADS)

Du, Daixian; Lin, Huimin; He, Zhenrong; Dai, Lingfen; Xin, Wusheng; Li, Shanghao

1990-12-01

The Fe protein of Anabaena cylindrica was first separated and purified by chromatography through DEAE-cellulose columns then by gel electrophoresis. The specific activity was up to 142.46 nmol C2H4/mg protein · min. It was homogeneous as shown by 1) a single band in the gel electrophorogram; 2) absence of Mo and tryptophan; 3) content of about 3.4 atoms of Fe per mole protein. The molecular weight of the Fe protein of A. cylindrica was about 61,000 daltons as estimated by SDS-gel electrophoresis and calculated from the amino acid composition. The residues of aspartate and glutamate were about 2.6 times that of arginine and lysine in the Fe protein. Crossing Fe protein of A. cylindrica with Mo-Fe protein of Azotobacter vinelandii gave positive result. The reciprocal crossing also showed activity.

Factors Determining the Biodiversity of Halophilic Microorganisms on Historic Masonry Buildings.

PubMed

Otlewska, Anna; Adamiak, Justyna; Stryszewska, Teresa; Kańka, Stanisław; Gutarowska, Beata

2017-06-24

The aim of the present study was to obtain insights into the relationship between the chemical (salt content and pH) and physico-mechanical (humidity and compressive strength) properties of mineral-based materials from historic buildings with salt efflorescence and the growth and biodiversity of halophilic microorganisms. Samples were mainly characterized by pH 6.5-8.5 and a moisture content of between 0.12 and 3.3%. Significant variations were also found in the salt content (sulfates, chlorides, and nitrates) of the materials. An SEM/EDS analysis of material surfaces revealed the presence of halite, calcite, gypsum, sodium sulfate, and potassium-sodium sulfate. Culture-dependent and culture-independent (clone library construction) approaches were both applied to detect halophilic microorganisms. Results derived from culturable methods and the materials analysis revealed a correlation between the total halophile count and pH value as well as sulfate content. A correlation was not observed between the concentration of chlorides or nitrates and the number of halophilic microorganisms. The materials studied were inhabited by the culturable halophilic bacteria Halobacillus sp., Virgibacillus sp., and Marinococcus sp. as well as the yeast Sterigmatomyces sp., which was isolated for the first time from mineral materials. Culture-independent techniques revealed the following bacterial species: Salinibacterium, Salinisphaera, Rubrobacter, Rubricoccus, Halomonas, Halorhodospira, Solirubrobacter, Salinicoccus, and Salinibacter. Biodiversity was the highest in materials with high or moderate salinity.

Factors Determining the Biodiversity of Halophilic Microorganisms on Historic Masonry Buildings

PubMed Central

Otlewska, Anna; Adamiak, Justyna; Stryszewska, Teresa; Kańka, Stanisław; Gutarowska, Beata

2017-01-01

The aim of the present study was to obtain insights into the relationship between the chemical (salt content and pH) and physico-mechanical (humidity and compressive strength) properties of mineral-based materials from historic buildings with salt efflorescence and the growth and biodiversity of halophilic microorganisms. Samples were mainly characterized by pH 6.5–8.5 and a moisture content of between 0.12 and 3.3%. Significant variations were also found in the salt content (sulfates, chlorides, and nitrates) of the materials. An SEM/EDS analysis of material surfaces revealed the presence of halite, calcite, gypsum, sodium sulfate, and potassium-sodium sulfate. Culture-dependent and culture-independent (clone library construction) approaches were both applied to detect halophilic microorganisms. Results derived from culturable methods and the materials analysis revealed a correlation between the total halophile count and pH value as well as sulfate content. A correlation was not observed between the concentration of chlorides or nitrates and the number of halophilic microorganisms. The materials studied were inhabited by the culturable halophilic bacteria Halobacillus sp., Virgibacillus sp., and Marinococcus sp. as well as the yeast Sterigmatomyces sp., which was isolated for the first time from mineral materials. Culture-independent techniques revealed the following bacterial species: Salinibacterium, Salinisphaera, Rubrobacter, Rubricoccus, Halomonas, Halorhodospira, Solirubrobacter, Salinicoccus, and Salinibacter. Biodiversity was the highest in materials with high or moderate salinity. PMID:28592721

Growth of Chlamydomonas reinhardtii in acetate-free medium when co-cultured with alginate-encapsulated, acetate-producing strains of Synechococcus sp. PCC 7002

DOE PAGES

Therien, Jesse B.; Zadvornyy, Oleg A.; Posewitz, Matthew C.; ...

2014-10-18

The model alga Chlamydomonas reinhardtii requires acetate as a co-substrate for optimal production of lipids, and the addition of acetate to culture media has practical and economic implications for algal biofuel production. We demonstrate the growth of C. reinhardtii on acetate provided by mutant strains of the cyanobacterium Synechococcus sp. PCC7002.

Organophosphonates utilization by soil strains of Ochrobactrum anthropi and Achromobacter sp.

PubMed

Ermakova, Inna T; Shushkova, Tatyana V; Sviridov, Alexey V; Zelenkova, Nina F; Vinokurova, Natalya G; Baskunov, Boris P; Leontievsky, Alexey A

2017-07-01

Four bacterial strains from glyphosate- or alkylphosphonates-contaminated soils were tested for ability to utilize different organophosphonates. All studied strains readily utilized methylphosphonic acid and a number of other phosphonates, but differed in their ability to degrade glyphosate. Only strains Ochrobactrum anthropi GPK 3 and Achromobacter sp. Kg 16 utilized this compound after isolation from enrichment cultures with glyphosate. Achromobacter sp. MPK 7 from the same enrichment culture, similar to Achromobacter sp. MPS 12 from methylphosphonate-polluted source, required adaptation to growth on GP. Studied strains varied significantly in their growth parameters, efficiency of phosphonates degradation and characteristic products of this process, as well as in their energy metabolism. These differences give grounds to propose a possible model of interaction between these strains in microbial consortium in phosphonate-contaminated soils.

Antagonistic activities of some Bifidobacterium sp. strains isolated from resident infant gastrointestinal microbiota on Gram-negative enteric pathogens.

PubMed

Delcaru, Cristina; Alexandru, Ionela; Podgoreanu, Paulina; Cristea, Violeta Corina; Bleotu, Coralia; Chifiriuc, Mariana Carmen; Bezirtzoglou, Eugenia; Lazar, Veronica

2016-06-01

The gastrointestinal microbiota contributes to the consolidation of the anti-infectious barrier against enteric pathogens. The purpose of this study was to investigate the influence of Bifidobacterium sp. strains, recently isolated from infant gastrointestinal microbiota on the in vitro growth and virulence features expression of enteropathogenic bacterial strains. The antibacterial activity of twelve Bifidobacterium sp. strains isolated from human feces was examined in vitro against a wide range of Gram negative pathogenic strains isolated from 30 infant patients (3 days to 5 years old) with diarrhea. Both potential probiotic strains (Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium catenulatum, Bifidobacterium breve, Bifidobacterium ruminantium) and enteropathogenic strains (EPEC, EIEC, Klebsiella pneumoniae, Salmonella sp., Yersinia enterocolitica, Pseudomonas aeruginosa) were identified by MALDI-TOF and confirmed serologically when needed. The bactericidal activity, growth curve, adherence to the cellular HEp-2 substratum and production of soluble virulence factors have been assessed in the presence of different Bifidobacterium sp. cultures and fractions (whole culture and free-cell supernatants). Among the twelve Bifidobacterium sp. strains, the largest spectrum of antimicrobial activity against 9 of the 18 enteropathogenic strains was revealed for a B. breve strain recently isolated from infant intestinal feces. The whole culture and free-cell supernatant of B. breve culture decreased the multiplication rate, shortened the log phase and the total duration of the growth curve, with an earlier entrance in the decline phase and inhibited the adherence capacity to a cellular substratum and the swimming/swarming motility too. These results indicate the significant probiotic potential of the B. breve strain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Metallomics and NMR-based metabolomics of Chlorella sp. reveal the synergistic role of copper and cadmium in multi-metal toxicity and oxidative stress.

PubMed

Zhang, Wenlin; Tan, Nicole G J; Fu, Baohui; Li, Sam F Y

2015-03-01

Industrial wastewaters often contain high levels of metal mixtures, in which metal mixtures may have synergistic or antagonistic effects on aquatic organisms. A combination of metallomics and nuclear magnetic resonance spectroscopy (NMR)-based metabolomics was employed to understand the consequences of multi-metal systems (Cu, Cd, Pb) on freshwater microalgae. Morphological characterization, cell viability and chlorophyll a determination of metal-spiked Chlorella sp. suggested synergistic effects of Cu and Cd on growth inhibition and toxicity. While Pb has no apparent effect on Chlorella sp. metabolome, a substantial decrease of sucrose, amino acid content and glycerophospholipid precursors in Cu-spiked microalgae revealed Cu-induced oxidative stress. Addition of Cd to Cu-spiked cultures induced more drastic metabolic perturbations, hence we confirmed that Cu and Cd synergistically influenced photosynthesis inhibition, oxidative stress and membrane degradation. Total elemental analysis revealed a significant decrease in K, and an increase in Na, Mg, Zn and Mn concentrations in Cu-spiked cultures. This indicated that Cu is more toxic to Chlorella sp. as compared to Cd or Pb, and the combination of Cu and Cd has a strong synergistic effect on Chlorella sp. oxidative stress induction. Oxidative stress is confirmed by liquid chromatography tandem mass spectrometry analysis, which demonstrated a drastic decrease in the GSH/GSSG ratio solely in Cu-spiked cultures. Interestingly, we observed Cu-facilitated Cd and Pb bioconcentration in Chlorella sp. The absence of phytochelatins and an increment of extracellular polymeric substances (EPS) yields in Cu-spiked cultures suggested that the mode of bioconcentration of Cd and Pb is through adsorption of free metals onto the algal EPS rather than intracellular chelation to phytochelatins.

Enhanced Oil Production by the Tropical Marine Diatom Thalassiosira Sp. Cultivated in Outdoor Photobioreactors.

PubMed

Kusumaningtyas, Pintaka; Nurbaiti, Santi; Suantika, Gede; Amran, Muhammad Bachri; Nurachman, Zeily

2017-08-01

Microalgae-derived oils have potential as a biofuel feedstock. To produce microalgal oils at a large scale, large amounts of nutrients and energy are needed to grow the algae. In this study, we evaluated three types of agricultural fertilizer (AF)-based culture media (AF1, AF2, and AF3) based on a previously published enriched seawater (ES) medium to produce biomass and oils from Thalassiosira sp. Under laboratory conditions, the highest cell productivity of Thalassiosira sp. was obtained with the AF3 medium. Thalassiosira sp. cultured in the AF3 medium produced 10.4 ± 0.9 mg L -1  day -1 oils, which is significantly higher than the 5.8 ± 0.7 mg L -1  day -1 produced in the ES medium. The higher production was due to the presence of nitrate and trace elements, both of which played roles in enhancing biomass and oil content, respectively. During cell growth, resting spores appeared inside the cells and were a marker to harvest the cells. Because of the abundant availability of sunlight in the tropics during the year, the oil production of Thalassiosira sp. in the AF3 medium was scaled up using outdoor photobioreactors under different weather conditions (rainy and dry seasons). Thalassiosira sp. produced more unsaturated fatty acids during the rainy season and produced more saturated fatty acids during the dry season. This study also demonstrated that it was possible to culture Thalassiosira sp. under outdoor conditions using a low-cost agricultural fertilizer-based culture medium (AF3 medium) to produce biodiesel feedstock with an annual production of 8.1 ± 0.4 t ha -1 during the dry season and of 23.9 ± 6.8 t ha -1 during the rainy season.

Substance P enhances collagen remodeling and MMP-3 expression by human tenocytes.

PubMed

Fong, Gloria; Backman, Ludvig J; Hart, David A; Danielson, Patrik; McCormack, Bob; Scott, Alex

2013-01-01

The loss of collagen organization is considered a hallmark histopathologic feature of tendinosis. At the cellular level, tenocytes have been shown to produce signal substances that were once thought to be restricted to neurons. One of the main neuropeptides implicated in tendinosis, substance P (SP), is known to influence collagen organization, particularly after injury. The aim of this study was to examine the influence of SP on collagen remodeling by primary human tendon cells cultured in vitro in three-dimensional collagen lattices. We found that SP stimulation led to an increased rate of collagen remodeling mediated via the neurokinin-1 receptor (NK-1 R), the preferred cell receptor for SP. Gene expression analysis showed that SP stimulation resulted in significant increases in MMP3, COL3A1 and ACTA2 mRNA levels in the collagen lattices. Furthermore, cyclic tensile loading of tendon cell cultures along with the administration of exogenous SP had an additive effect on MMP3 expression. Immunoblotting confirmed that SP increased MMP3 protein levels via the NK-1 R. This study indicates that SP, mediated via NK-1 R, increases collagen remodeling and leads to increased MMP3 mRNA and protein expression that is further enhanced by cyclic mechanical loading. Copyright © 2012 Orthopaedic Research Society.

Substance P and neurokinin A in human nasal mucosa.

PubMed

Baraniuk, J N; Lundgren, J D; Okayama, M; Goff, J; Mullol, J; Merida, M; Shelhamer, J H; Kaliner, M A

1991-03-01

The tachykinins substance P (SP) and neurokinin A (NKA) were studied in human inferior turbinate nasal mucosa by radioimmunoassay, immunohistochemistry, and autoradiography and for their effect upon mucus release in an in vitro culture system in order to infer their potential functions in the upper respiratory tract. Similar amounts of SP (1.03 +/- 0.12 pmol/g wet weight; mean +/- SEM; n = 26) and NKA (0.76 +/- 0.23; n = 7) were found. NKA and SP immunoreactive nerve fibers were found in the walls of arterioles, venules, and sinusoids and as individual fibers in gland acini, near the basement membrane, and in the epithelium. [125I]SP bound to arterioles, venules, and glands. [125I]NKA bound only to arterioles. In short-term explant culture of fragments of human nasal mucosa, both 1 microM SP and 1 microM NKA stimulated release of [3H]glucosamine-labeled respiratory glycoconjugates. These results indicate that SP and NKA have similar distributions in nociceptive sensory nerves in human nasal mucosa. The distribution of [125I]SP binding sites is consistent with a role for SP as a vasodilator and mucous secretagogue. The presence of [125I] NKA binding sites on vessels suggests a primary role for NKA in regulating vasomotor tone.

Growth in coculture stimulates metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2.

PubMed

Sørensen, Sebastian R; Ronen, Zeev; Aamand, Jens

2002-07-01

Metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2 was significantly enhanced when the strain was grown in coculture with a soil bacterium (designated strain SRS1). Both members of this consortium were isolated from a highly enriched isoproturon-degrading culture derived from an agricultural soil previously treated regularly with the herbicide. Based on analysis of the 16S rRNA gene, strain SRS1 was assigned to the beta-subdivision of the proteobacteria and probably represents a new genus. Strain SRS1 was unable to degrade either isoproturon or its known metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, or 4-isopropyl-aniline. Pure culture studies indicate that Sphingomonas sp. SRS2 is auxotrophic and requires components supplied by association with other soil bacteria. A specific mixture of amino acids appeared to meet these requirements, and it was shown that methionine was essential for Sphingomonas sp. SRS2. This suggests that strain SRS1 supplies amino acids to Sphingomonas sp. SRS2, thereby leading to rapid metabolism of (14)C-labeled isoproturon to (14)CO(2) and corresponding growth of strain SRS2. Proliferation of strain SRS1 suggests that isoproturon metabolism by Sphingomonas sp. SRS2 provides unknown metabolites or cell debris that supports growth of strain SRS1. The role of strain SRS1 in the consortium was not ubiquitous among soil bacteria; however, the indigenous soil microflora and some strains from culture collections also stimulate isoproturon metabolism by Sphingomonas sp. strain SRS2 to a similar extent.

Growth in Coculture Stimulates Metabolism of the Phenylurea Herbicide Isoproturon by Sphingomonas sp. Strain SRS2

PubMed Central

Sørensen, Sebastian R.; Ronen, Zeev; Aamand, Jens

2002-01-01

Metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2 was significantly enhanced when the strain was grown in coculture with a soil bacterium (designated strain SRS1). Both members of this consortium were isolated from a highly enriched isoproturon-degrading culture derived from an agricultural soil previously treated regularly with the herbicide. Based on analysis of the 16S rRNA gene, strain SRS1 was assigned to the β-subdivision of the proteobacteria and probably represents a new genus. Strain SRS1 was unable to degrade either isoproturon or its known metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, or 4-isopropyl-aniline. Pure culture studies indicate that Sphingomonas sp. SRS2 is auxotrophic and requires components supplied by association with other soil bacteria. A specific mixture of amino acids appeared to meet these requirements, and it was shown that methionine was essential for Sphingomonas sp. SRS2. This suggests that strain SRS1 supplies amino acids to Sphingomonas sp. SRS2, thereby leading to rapid metabolism of 14C-labeled isoproturon to 14CO2 and corresponding growth of strain SRS2. Proliferation of strain SRS1 suggests that isoproturon metabolism by Sphingomonas sp. SRS2 provides unknown metabolites or cell debris that supports growth of strain SRS1. The role of strain SRS1 in the consortium was not ubiquitous among soil bacteria; however, the indigenous soil microflora and some strains from culture collections also stimulate isoproturon metabolism by Sphingomonas sp. strain SRS2 to a similar extent. PMID:12089031

Sodium: some effects on bluegreen algal growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, A.K.; Wetzel, R.G.

The growth of heterocystous bluegreen algae in various concentrations of sodium was examined in axenic culture as well as in situ studies. Anabaena cylindrica Lemm, with no Na/sup +/ added, suffered from decreased rates of acetylene reduction, /sup 14/C assimilation, excretion of organic C as well as lower concentrations of chlorophyll a and particulate organic C compared to cultures supplied with 5, 10, and 50 mg Na/sup +/ . l/sup -1/. Sodium deficient algae released extracellularly a higher percentage of previously fixed C as organic C. No differences in any parameter measured were demonstrable among cultures grown with 5, 10,more » and 50 mg Na/sup +/ . l/sup -1/. High nitrate concentrations (20 mg NO/sub 3/- . /sup -1/) resulted in decreased rates of acetylene reduction and heterocyst numbers in Na sufficient and Na deficient cultures; however, decreased cellular Na content at high NO/sub 3/- levels occurred only in N deficient cultures. Higher percentages of excreted organic C occurred with increasing NO/sub 3/- concentrations in Na deficient cultures. Sodium enrichment of natural bluegreen populations with the addition of 50, 100, and 200 mg Na/sup +/ . l/sup -1/ elicited neither a stimulatory nor an inhibitory response in photosynthetic C fixation. In contrast, the addition of small amounts of Na/sup +/ (5 mg . l/sup -1/) resulted in increased C fixation. However, since the Na concentration of the lake water, at ca. 5 mg Na/sup +/ . l/sup -1/, was sufficient for growth of the bluegreens present, sodium is not assumed to be limiting under most natural conditions. No increase in in situ acetylene reduction rates occurred with additions of sodium.« less

Formalin produces depolarizations in human airway smooth muscle in vitro.

PubMed

Richards, Ira S; DeHate, Robin B

2006-03-01

Respiratory irritants may result in airway smooth muscle (ASM) depolarization and bronchoconstriction. We examined the effect of formalin on membrane potentials in human ASM in two types of in vitro preparations: strip preparations, which contain functional sensory and motor nerve endings and cultured cells, which lack these nerve endings due to the tissue dissociation process. Depolarizations occurred in atropine-treated strip preparations in response to formalin exposures, but not in similarly-treated cultured cells, suggesting a role for non-cholinergic mediators in formalin-induced depolarization. It is suggested that formalin may act as an irritant to produce bronchoconstriction that is mediated by the release of endogenous substance P (SP) from peripheral sensory nerve endings. This is supported by our observation that exogenous SP produced depolarizations of a magnitude similar to those produced by formalin in both strip preparations and cultured cells. In addition, capsaicin, which releases endogenous SP from nerve endings, produced depolarizations of a magnitude similar to formalin in strip preparations, but was without effect in cultured cells.

Cultural Resources Survey of Palmetto and Coochie Revetments, Mississippi River M-326 to 315

DTIC Science & Technology

1993-11-11

oils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Sedim entary...wildlife are asters (Aster sp.), buck vine (Amelopsis arborea), dewberry (Rubus sp.), elderberry ( Sambucus canadensis), and various maples (Acer sp...time characterized by a "filling in" of regional areas by peoples adapting to essentially modern natural environments. The concept of an Archaic Stage

Application of MSSIP-2 nutrient in marine phytoplankton culture to support the production of biomass for biofuel industry

NASA Astrophysics Data System (ADS)

Taba, Paulina; Kasim, S.; Raya, I.

2018-03-01

A research on the application of MSSIP-2 nutrient in marine phytoplankton culture has been conducted to produce biomass to be used as raw material for biofuel. Marine phytoplankton was cultivated using the nutrient media and the growth rates were studied by measuring the cell solidity at various growth times. Seven phytoplanktons; Isochrysis aff galbana, Spirulina sp., Thalassiosira sp., and Nitzchia sp., Chlorella vulgaris, Chaetoceros calcitrans and Isochrysis tahiti were used in the research. The experimental temperature, salinity, and pH of the media were measured and the specific growth rates of phytoplanktons were determined using the first order rate equation. Results showed that the highest specific growth rate was given by Chlorella vulgaris (0.0322 cells/hour) and the lowest one was by Thalassiosira sp. (0.0277 cells/hour). The highest biomass weight was obtained from Isochrysis aff galbana (0.329 g), whereas the lowest one (0.27 g) was from Nitzchia sp. The carbohydrate content was various, the highest content was 34.07% found in Isochrysis aff galbana and the lowest was 28.16% in Thalassiosira sp.

Solar energy conversion through biophotolysis. Third annual report, 1 April 1978-31 March 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benemann, J.R.; Murry, M.A.; Hallenbeck, P.C.

This report covers the progress during the third year of this project. The state-of-the-art of biophotolysis was reviewed and a bioengineering analysis carried out. The conclusions were that practical biophotolysis systems are feasible; however, they will require, in most cases, relatively long-term R and D. The biophotolysis system developed under this project, utilizing heterocystous blue-green algae, was demonstrated both indoors and outdoors with a model converter system using the heterocystous blue-grees alga Anabaena cylindrica. Maximal light energy conversion efficiencies were 2.5% indoors and about 0.2% outdoors, averaged for periods of about two weeks. Achievement of such rates required optimization ofmore » N/sub 2/ supply and culture density. A small amount of N/sub 2/ in the argon gas phase used to sparge the cultures was beneficial to the stability of a long-term hydrogen-production activity. A relatively small amount of the hydrogen produced by these cultures can be ascribed to the activity of the reversible hydrogenase which was studied by nitrogenase inactivation through poisoning with tungstate. The regulation of nitrogenase activity in these algae was studied through physiological and immunochemical methods. In particular, the oxygen protection mechanism was examined. Thermophilic blue-green algae have potential for biophotolysis; hydrogen production was studied in the laboratory. Preliminary experiments on the photofermentation of organic substrates to hydrogen was studied with photosynthetic bacteria.« less

Solar energy conversion through biophotolysis. Third annual report, April 1, 1978-March 31, 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benemann, J.R.; Murry, M.A.; Hallenbeck, P.C.

This report covers the progress during the third year of this project. The state-of-the-art of biophotolysis was reviewed and a bioengineering analysis carried out. The conclusions were that practical biophotolysis systems are feasible; however, they will require, in most cases, relatively long-term R and D. The biophotolysis system developed under this project, utilizing heterocystous blue-green algae, was demonstrated both indoors and outdoors with a model converter system using the heterocystous blue-green alga Anabaena cylindrica. Maximal light energy conversion efficiencies were 2.5% indoors and about 0.2% outdoors, averaged for periods of about two weeks. Achievement of such rates required optimization ofmore » N/sub 2/ supply and culture density. A small amount of N/sub 2/ in the argon gas phase used to sparge the cultures was beneficial to the stability of a long-term hydrogen-production activity. A relatively small amount of the hydrogen produced by these cultures can be ascribed to the activity of the reversible hydrogenase which was studied by nitrogenase inactivation through poisoning with tungstate. The regulation of nitrogenase activity in these algae was studied through physiological and immunochemical methods. In particular, the oxygen protection mechanism was examined. Thermophilic blue-green algae have potential for biophotolysis; hydrogen production was studied in the laboratory. Preliminary experiments on the photofermentation of organic substrates to hydrogen was studied with photosynthetic bacteria.« less

Unusual Versatility of the Filamentous, Diazotrophic Cyanobacterium Anabaena torulosa Revealed for Its Survival during Prolonged Uranium Exposure.

PubMed

Acharya, Celin; Chandwadkar, Pallavi; Nayak, Chandrani

2017-05-01

Reports on interactions between cyanobacteria and uranyl carbonate are rare. Here, we present an interesting succession of the metabolic responses employed by a marine, filamentous, diazotrophic cyanobacterium, Anabaena torulosa for its survival following prolonged exposure to uranyl carbonate extending up to 384 h at pH 7.8 under phosphate-limited conditions. The cells sequestered uranium (U) within polyphosphates on initial exposure to 100 μM uranyl carbonate for 24 to 28 h. Further incubation until 120 h resulted in (i) significant degradation of cellular polyphosphates causing extensive chlorosis and cell lysis, (ii) akinete differentiation followed by (iii) extracellular uranyl precipitation. X-ray diffraction (XRD) analysis, fluorescence spectroscopy, X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) spectroscopy established the identity of the bioprecipitated uranium as a U(VI) autunite-type mineral, which settled at the bottom of the vessel. Surprisingly, A. torulosa cells resurfaced as small green flakes typical of actively growing colonies on top of the test solutions within 192 to 240 h of U exposure. A consolidated investigation using kinetics, microscopy, and physiological and biochemical analyses suggested a role of inducible alkaline phosphatase activity of cell aggregates/akinetes in facilitating the germination of akinetes leading to substantial regeneration of A. torulosa by 384 h of uranyl incubation. The biomineralized uranium appeared to be stable following cell regeneration. Altogether, our results reveal novel insights into the survival mechanism adopted by A. torulosa to resist sustained uranium toxicity under phosphate-limited oxic conditions. IMPORTANCE Long-term effects of uranyl exposure in cyanobacteria under oxic phosphate-limited conditions have been inadequately explored. We conducted a comprehensive examination of the metabolic responses displayed by a marine cyanobacterium, Anabaena torulosa , to cope with prolonged exposure to uranyl carbonate at pH 7.8 under phosphate limitation. Our results highlight distinct adaptive mechanisms harbored by this cyanobacterium that enabled its natural regeneration following extensive cell lysis and uranium biomineralization under sustained uranium exposure. Such complex interactions between environmental microbes such as Anabaena torulosa and uranium over a broader time range advance our understanding on the impact of microbial processes on uranium biogeochemistry. Copyright © 2017 American Society for Microbiology.

Genetic element from human surfactant protein SP-C gene confers bronchiolar-alveolar cell specificity in transgenic mice.

PubMed

Glasser, S W; Korfhagen, T R; Wert, S E; Bruno, M D; McWilliams, K M; Vorbroker, D K; Whitsett, J A

1991-10-01

Transgenic mice bearing chimeric genes consisting of 5'-sequences derived from the human surfactant protein C (SP-C) gene and the bacterial chloramphenicol acetyltransferase (CAT) gene were generated. Analysis of CAT activity was utilized to demonstrate tissue-specific and developmental expression of chimeric genes containing 3.7 kb of sequences from the human SP-C gene. Lung-specific expression of the 3.7 SP-C-CAT transgene was observed in eight distinct transgenic mouse lines. Expression of the 3.7 SP-C-CAT transgene was first detected in fetal lung on day 11 of gestation and increased dramatically with advancing gestational age, reaching adult levels of activity before birth. In situ hybridization demonstrated that expression of 3.7 SP-C-CAT mRNA was confined to the distal respiratory epithelium. Antisense CAT hybridization was detected in bronchiolar and type II epithelial cells in the adult lung of the 3.7 SP-C-CAT transgenic mice. In situ hybridization of four distinct 3.7 SP-C-CAT transgenic mouse lines demonstrated bronchiolar-alveolar expression of the chimeric CAT gene, although the relative intensity of expression at each site varied within the lines studied. Glucocorticoids increased murine SP-C mRNA in fetal lung organ culture. Likewise, expression of 3.7 SP-C-CAT transgene increased during fetal lung organ or explant culture and was further enhanced by glucocorticoid in vitro. The 5'-regions of human SP-C conferred developmental, lung epithelial, and glucocorticoid-enhanced expression of bacterial CAT in transgenic mice. The increased expression of SP-C accompanying prenatal lung development and exposure to glucocorticoid is mediated, at least in part, at the transcriptional level, being influenced by cis-active elements contained within the 5'-flanking region of the human SP-C gene.

Culturable Aerobic and Facultative Anaerobic Intestinal Bacterial Flora of Black Cobra (Naja naja karachiensis) in Southern Pakistan

PubMed Central

Iqbal, Junaid; Sagheer, Mehwish; Tabassum, Nazneen; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

2014-01-01

Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections. PMID:25002979

The long-term effect of uranium and pH on the community composition of an artificial consortium.

PubMed

Brzoska, Ryann M; Bollmann, Annette

2016-01-01

In the environment, microorganisms are living in diverse communities, which are impacted by the prevailing environmental conditions. Here, we present a study investigating the effect of low pH and elevated uranium concentration on the dynamics of an artificial microbial consortium. The members (Caulobacter sp. OR37, Asinibacterium sp. OR53, Ralstonia sp. OR214 and Rhodanobacter sp. OR444) were isolated from a uranium contaminated and acidic subsurface sediment. In pure culture, Ralstonia sp. OR214 had the highest growth rate at neutral and low pH and only Caulobacter sp. OR37 and Asinibacterium sp. OR53 grew in the presence uranium. The four strains were mixed in equal ratios, incubated at neutral and low pH and in the presence uranium and transferred to fresh medium once per week for 30 weeks. After 30 weeks, Ralstonia sp. OR214 was dominant at low and neutral pH and Caulobacter sp. OR37 and Asinibacterium sp. OR53 were dominant in the presence of uranium. After 12 weeks, the cultures were also transferred to new conditions to access the response of the consortia to changing conditions. The transfers showed an irreversible effect of uranium, but not of low pH on the consortia. Overall, the strains initially tolerant to the respective conditions persisted over time in high abundances in the consortia. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effect of tea saponin on ephyrae and polyps of the moon jellyfish Aurelia sp.1.

PubMed

Dong, Zhijun; Sun, Tingting; Liang, Likun; Wang, Lei

2017-01-01

The moon jellyfish (Aurelia sp.1) is thought to be a nuisance for the sea cucumber aquaculture, which commonly occur in the sea cucumber (Apostichopus japonicus) culture ponds of the Yellow Sea, China. To develop an appropriate method to control Aurelia sp.1 blooms, the toxic effects of tea saponin on Aurelia sp.1 ephyrae and polyps were tested in laboratory experiments. Our results revealed that tea saponin caused significant morphological changes, behavioral abnormality and mortality in Aurelia sp.1 ephyrae and polyps in 24 h and 48 h exposure experiments. The 24 h and 48 h median lethal concentrations (LC50) values of tea saponin for Aurelia sp.1 ephyrae were 1.9 and 1.1 mg L-1 respectively, while the LC50 value for Aurelia sp.1 polyps was 0.4 mg L-1 after 24h and 48 h of exposure to tea saponin. Comparison with literature results of tea saponin on A. japonicus indicates that the resistance of A. japonicus to tea saponin is 12-18 times greater than that of Aurelia sp.1 ephyrae. Therefore, the appropriate tea saponin dosage for the control of Aurelia sp.1 should be paid enough attention in order to minimize possible damage for sea cucumber. We suggest that the recommended level of tea saponin to eradicate Aurelia sp.1 ephyrae and polyps in sea cucumber culture ponds be lower than 1.35 mg L-1.

Effect of tea saponin on ephyrae and polyps of the moon jellyfish Aurelia sp.1

PubMed Central

Sun, Tingting; Liang, Likun; Wang, Lei

2017-01-01

The moon jellyfish (Aurelia sp.1) is thought to be a nuisance for the sea cucumber aquaculture, which commonly occur in the sea cucumber (Apostichopus japonicus) culture ponds of the Yellow Sea, China. To develop an appropriate method to control Aurelia sp.1 blooms, the toxic effects of tea saponin on Aurelia sp.1 ephyrae and polyps were tested in laboratory experiments. Our results revealed that tea saponin caused significant morphological changes, behavioral abnormality and mortality in Aurelia sp.1 ephyrae and polyps in 24 h and 48 h exposure experiments. The 24 h and 48 h median lethal concentrations (LC50) values of tea saponin for Aurelia sp.1 ephyrae were 1.9 and 1.1 mg L-1 respectively, while the LC50 value for Aurelia sp.1 polyps was 0.4 mg L-1 after 24h and 48 h of exposure to tea saponin. Comparison with literature results of tea saponin on A. japonicus indicates that the resistance of A. japonicus to tea saponin is 12–18 times greater than that of Aurelia sp.1 ephyrae. Therefore, the appropriate tea saponin dosage for the control of Aurelia sp.1 should be paid enough attention in order to minimize possible damage for sea cucumber. We suggest that the recommended level of tea saponin to eradicate Aurelia sp.1 ephyrae and polyps in sea cucumber culture ponds be lower than 1.35 mg L-1. PMID:28777817

Enhancing methyl parathion degradation by the immobilization of Burkholderia sp. isolated from agricultural soils.

PubMed

Fernández-López, Maikel Gilberto; Popoca-Ursino, Carolina; Sánchez-Salinas, Enrique; Tinoco-Valencia, Raunel; Folch-Mallol, Jorge Luis; Dantán-González, Edgar; Laura Ortiz-Hernández, Ma

2017-10-01

Organophosphate pesticides are of great interest for research because they are currently the most commonly used pesticides. In this study, a bacterial strain capable of completely degrading methyl parathion (MP) was isolated from agricultural soils in central Mexico. This strain was designated strain S5-2 and was identified as Burkholderia cenocepacia. To increase degradation yields, cells were immobilized on three different supports: powdered zeolite and Opuntia sp. and Agave sp. fibers. The results indicated a significant increase in MP hydrolysis and p-nitrophenol (PNP) degradation with immobilized cells compared to free cell cultures. Furthermore, immobilized cells were capable of withstanding and degrading higher concentrations of PNP compared to cell suspension cultures. The cell viability in the free cell cultures, as well as PNP degradation, was affected at concentrations greater than 25 mg/L. In contrast, cells immobilized on Opuntia sp. and Agave sp. fibers completely degraded PNP at concentrations of 100 mg/L. To verify that MP solution toxicity was decreased by B. cenocepacia strain S5-2 via pesticide degradation, we measured the acetylcholinesterase activity, both before and after treatment with bacteria. The results demonstrate that the activity of acetylcholinesterase was unaffected after MP degradation by bacteria. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Complete Genome Sequence of Petrimonas sp. Strain IBARAKI, Assembled from the Metagenome Data of a Culture Containing Dehalococcoides spp.

PubMed

Ikegami, Kentaro; Aita, Yuto; Shiroma, Akino; Shimoji, Makiko; Tamotsu, Hinako; Ashimine, Noriko; Shinzato, Misuzu; Ohki, Shun; Nakano, Kazuma; Teruya, Kuniko; Satou, Kazuhito; Hirano, Takashi; Yohda, Masafumi

2018-05-03

The complete genome sequence of Petrimonas sp. strain IBARAKI in a Dehalococcoides -containing culture was determined using the PacBio RS II platform. The genome is a single circular chromosome of 3,693,233 nucleotides (nt), with a GC content of 44%. This is the first genome sequence of a Petrimonas species. Copyright © 2018 Ikegami et al.

A method of batch-purifying microalgae with multiple antibiotics at extremely high concentrations

NASA Astrophysics Data System (ADS)

Han, Jichang; Wang, Song; Zhang, Lin; Yang, Guanpin; Zhao, Lu; Pan, Kehou

2016-01-01

Axenic microalgal strains are highly valued in diverse microalgal studies and applications. Antibiotics, alone or in combination, are often used to avoid bacterial contamination during microalgal isolation and culture. In our preliminary trials, we found that many microalgae ceased growing in antibiotics at extremely high concentrations but could resume growth quickly when returned to an antibiotics-free liquid medium and formed colonies when spread on a solid medium. We developed a simple and highly efficient method of obtaining axenic microalgal cultures based on this observation. First, microalgal strains of different species or strains were treated with a mixture of ampicillin, gentamycin sulfate, kanamycin, neomycin and streptomycin (each at a concentration of 600 mg/L) for 3 days; they were then transferred to antibiotics-free medium for 5 days; and finally they were spread on solid f/2 media to allow algal colonies to form. With this method, five strains of Nannochloropsis sp. (Eustigmatophyceae), two strains of Cylindrotheca sp. (Bacillariophyceae), two strains of Tetraselmis sp. (Chlorodendrophyceae) and one strain of Amphikrikos sp. (Trebouxiophyceae) were purified successfully. The method shows promise for batch-purifying microalgal cultures.

Effects of different culture media on biodegradation of triclosan by Rhodotorula mucilaginosa and Penicillium sp.

PubMed

Ertit Taştan, Burcu; Özdemir, Caner; Tekinay, Turgay

Triclosan is an antimicrobial agent and a persistent pollutant. The biodegradation of triclosan is dependent on many variables including the biodegradation organism and the environmental conditions. Here, we evaluated the triclosan degradation potential of two fungi strains, Rhodotorula mucilaginosa and Penicillium sp., and the rate of its turnover to 2,4-dichlorophenol (2,4-DCP). Both of these strains showed less susceptibility to triclosan when grown in minimal salt medium. In order to further evaluate the effects of environmental conditions on triclosan degradation, three different culture conditions including original thermal power plant wastewater, T6 nutrimedia and ammonium mineral salts medium were used. The maximum triclosan degradation yield was 48% for R. mucilaginosa and 82% for Penicillium sp. at 2.7 mg/L triclosan concentration. Biodegradation experiments revealed that Penicillium sp. was more tolerant to triclosan. Scanning electron microscopy micrographs also showed the morphological changes of fungus when cells were treated with triclosan. Overall, these fungi strains could be used as effective microorganisms in active uptake (degradation) and passive uptake (sorption) of triclosan and their efficiency can be increased by optimizing the culture conditions.

Sub-Cellular Localization and Complex Formation by Aminoacyl-tRNA Synthetases in Cyanobacteria: Evidence for Interaction of Membrane-Anchored ValRS with ATP Synthase.

PubMed

Santamaría-Gómez, Javier; Ochoa de Alda, Jesús A G; Olmedo-Verd, Elvira; Bru-Martínez, Roque; Luque, Ignacio

2016-01-01

tRNAs are charged with cognate amino acids by aminoacyl-tRNA synthetases (aaRSs) and subsequently delivered to the ribosome to be used as substrates for gene translation. Whether aminoacyl-tRNAs are channeled to the ribosome by transit within translational complexes that avoid their diffusion in the cytoplasm is a matter of intense investigation in organisms of the three domains of life. In the cyanobacterium Anabaena sp. PCC 7120, the valyl-tRNA synthetase (ValRS) is anchored to thylakoid membranes by means of the CAAD domain. We have investigated whether in this organism ValRS could act as a hub for the nucleation of a translational complex by attracting other aaRSs to the membranes. Out of the 20 aaRSs, only ValRS was found to localize in thylakoid membranes whereas the other enzymes occupied the soluble portion of the cytoplasm. To investigate the basis for this asymmetric distribution of aaRSs, a global search for proteins interacting with the 20 aaRSs was conducted. The interaction between ValRS and the FoF1 ATP synthase complex here reported is of utmost interest and suggests a functional link between elements of the gene translation and energy production machineries.

Biotreatment of industrial olive washing water by synergetic association of microalgal-bacterial consortia in a photobioreactor.

PubMed

Maza-Márquez, P; González-Martínez, A; Martínez-Toledo, M V; Fenice, M; Lasserrot, A; González-López, J

2017-01-01

This study presents an effective technology for the olive processing industry to remediate olive washing water. A 14.5-L enclosed tubular photobioreactor was inoculated with a stable microalgal-bacterial consortium obtained by screening strains well adapted to olive washing water. The capacity of an enclosed tubular photobioreactor to remove toxic compounds was evaluated under photosynthesis conditions and without any external supply of oxygen. The results showed that the dominant green microalgae Scenedesmus obliquus, Chlorella vulgaris and the cyanobacteria Anabaena sp. and bacteria present in olive washing water (i.e. Pantoea agglomerans and Raoultella terrigena) formed a synergistic association that was resistant to toxic pollutants present in the effluent and during the initial biodegradation process, which resulted in the breakdown of the pollutant. Total phenolic compounds, COD, BOD 5 , turbidity and colour removals of 90.3 ± 11.4, 80.7 ± 9.7, 97.8 ± 12.7, 82.9 ± 8.4 and 83.3 ± 10.4 %, respectively, were recorded in the photobioreactor at 3 days of hydraulic retention time. Graphical abstract Biotreatment of industrial olive washing water by synergetic association of microalgal-bacterial consortia in a photobioreactor.

Interspecific and intraspecific diversity and interaction of cyanobacteria throughout a bloom

EPA Science Inventory

Using high throughput 16S rRNA gene sequencing of samples from a complete bloom cycle, Cyanobacteria had five main genera, Planktothrix, Aphanizomenon, Dolichospermum, Microcystis and Cylindrospermopsis, along with three minor genera Anabaena, Oscillatoria, and Leptolyngbya. Many...

Intermittent illumination increases biophotolytic hydrogen yield by Anabaena cylindrica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeffries, T.W.; Leach, K.L.

Intermittent illumination increased H/sub 2/ and C/sub 2/H/sub 4/ yields per unit of light from growing cells and from nitrogen-starved cells by 1.7- and 1.35-fold, respectively, as compared with continuous illumination.

Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria

PubMed Central

da Silva, Fábio Daniel Florêncio; Lima, Alex Ranieri Jerônimo; Moraes, Pablo Henrique Gonçalves; Siqueira, Andrei Santos; Dall’Agnol, Leonardo Teixeira; Baraúna, Anna Rafaella Ferreira; Martins, Luisa Carício; Oliveira, Karol Guimarães; de Lima, Clayton Pereira Silva; Nunes, Márcio Roberto Teixeira; Vianez-Júnior, João Lídio Silva Gonçalves

2016-01-01

Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here. PMID:27198027

Floating cultivation of marine cyanobacteria using coal fly ash.

PubMed

Matsumoto, M; Yoshida, E; Takeyama, H; Matsunaga, T

2000-01-01

The aim of this study was to develop improved methodologies for bulk culturing of biotechnologically useful marine cyanobacteria in the open ocean. We have investigated the viability of using coal fly ash (CFA) blocks as the support medium in a novel floating culture system for marine micro-algae. The marine cyanobacterium Synechococcus sp. NKBG 040607 was found to adhere to floating CFA blocks in liquid culture medium. Maximum density of attached cells of 2.0 x 10(8) cells/cm2 was achieved using seawater. The marine cyanobacterium Synechococcus sp. NKBG 042902 weakly adhered to floating CFA blocks in BG-11 medium. Increasing the concentration of calcium ion in the culture medium enhanced adherence to CFA blocks.

Effects of temperature and glucose limitation on coal solubilization by Candida ML13

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, B.

1991-04-01

Biological processing has received considerable attention in recent years as a technology for the utilization of low-ranked coals. Several fungi and actinomycetes have been shown to liquefy highly oxidized coal in pure culture under aerobic conditions. This report describes the optimization of cultural conditions for coal solubilization by Candida sp. ML13, an organism originally isolated from a naturally weathered coal seam. Coal solubilization by surface cultures of Candida sp. has previously been demonstrated. The author describes here the elicitation of the activity in submerged cultures as well as the effect of carbohydrate concentration, carbon source, temperature, and agitation rate onmore » coal solubilization by this organism.« less

Gastrointestinal parasites of mountain gorillas (Gorilla gorilla beringei) in the Parc National des Volcans, Rwanda.

PubMed

Sleeman, J M; Meader, L L; Mudakikwa, A B; Foster, J W; Patton, S

2000-09-01

Ninety-eight fecal samples were collected from 74 free-living mountain gorillas (Gorilla gorilla beringei) from the Parc National des Volcans, Rwanda, between July 1995 and January 1997 and examined for parasites by Sheather's sugar and zinc sulfate flotation methods, trichrome staining, and larval cultures. All samples contained at least one parasite. Seventeen endoparasites were identified, including eight protozoa, seven nematodes, one cestode, and one trematode. Two species of arthropod mite were also recovered from the fecal samples. Parasites observed on fecal examinations included strongyle/trichostrongyle-type eggs (72/74) (representing Oesphagostomum sp., Trichostrongylus sp., Hyostrongylus spp., and possibly Murshidia sp.), Strongyloides sp. (1/74), Trichuris trichiura (2/74), Probstmayria sp. (7/74), Anoplocephala sp. (63/74), Entamoeba hartmanni cysts and trophozoites (19/70), Endolimax nana cysts (31/70), Iodamoeba buetschlii cysts (11/70), Endolimax nana or Iodamoeba buetschlii trophozoites (63/70). Entamoeba coli cysts and trophozoites (14/70), Entamoeba histolytica trophozoite (1/70), Chilomastix sp. cysts and trophozoites (31/70), and Giardia sp. cysts (2/70). In addition, one ascarid and one trematode egg were seen. There were no significant differences in the prevalence of parasites between males and females and between age groups: however, infants and juveniles appeared to have a lower prevalence of Anoplocephala gorillae, and the silverbacked males appeared to have a higher prevalence of Probstmayria sp. Parasite prevalence was consistent among the five social groups studied except Susa group had a significantly lower prevalence of Anoplocephala gorillae. Trichuris trichiura, Strongyloides sp., Chilomastix sp., and Endolimax nana were identified for the first time in this population, and it is possible that these parasites were of human origin. Although there were no obvious clinical effects due to the presence of these parasites, six parasites identified (Trichuris trichiura, Strongyloides sp., Oesphagostomum sp., Trichostrongylus sp., Entamoeba histolytica, and Giardia sp.) could potentially be pathogenic. Some of the parasite products and cultured larvae could not be speciated.

In vitro comparative analysis of monocrotophos degrading potential of Aspergillus flavus, Fusarium pallidoroseum and Macrophomina sp.

PubMed

Jain, Rachna; Garg, Veena; Yadav, Deepak

2014-06-01

Fungal degradation is emerging as a new powerful tool for the removal of potent neurotoxin pesticide, monocrotophos. Therefore, the present study is aimed at comparative characterization of monocrotophos degrading ability of three different fungal strains. Fungal strains were isolated from local agricultural soil by enrichment culture method, screened by gradient culture and identified as Aspergillus flavus, Fusarium pallidoroseum and Macrophomina sp. Growth kinetics revealed a direct positive influence of monocrotophos on the viability of fungal isolates. Fungal degradation was studied in phosphorus free liquid culture medium supplemented with 150 mg L(-1) concentration of monocrotophos for a period of 15 days under optimized culture conditions. Degradation of MCP followed first order kinetics with kdeg of 0.007, 0.002 and 0.005 day(-1) and half life (t1/2) of 4.21, 12.64 and 6.32 days for A. flavus, F. pallidoroseum and Macrophomina sp. respectively. To the best of our knowledge, it is the first report signifying the potential of monocrotophos degradation by Fusarium and Macrophomina sp. The results were further confirmed by HPTLC and FTIR which indicates disappearance of monocrotophos by hydrolytic cleavage of vinyl phosphate bond. Degradation of monocrotophos by fungal isolates was accompanied by the release of extracellular alkaline phosphatases, inorganic phosphates and ammonia. The overall comparative analysis followed the order of A. flavus > Macrophomina sp. > F. pallidoroseum. Therefore, it could be concluded from the study that these three different fungal strains could be effectively used as a potential candidate for the removal of monocrotophos from contaminated sites.

Enhanced polyaromatic hydrocarbon degradation by adapted cultures of actinomycete strains.

PubMed

Bourguignon, Natalia; Isaac, Paula; Alvarez, Héctor; Amoroso, María J; Ferrero, Marcela A

2014-12-01

Fifteen actinomycete strains were evaluated for their potential use in removal of polycyclic aromatic hydrocarbons (PAH). Their capability to degrade of naphthalene, phenanthrene, and pyrene was tested in minimal medium (MM) and MM with glucose as another substrate. Degradation of naphthalene in MM was observed in all isolates at different rates, reaching maximum values near to 76% in some strains of Streptomyces, Rhodococcus sp. 016 and Amycolatopsis tucumanensis DSM 45259. Maximum values of degradation of phenanthrene in MM occurred in cultures of A. tucumanensis DSM 45259 (36.2%) and Streptomyces sp. A12 (20%), while the degradation of pyrene in MM was poor and only significant with Streptomyces sp. A12 (4.3%). Because of the poor performance when growing on phenanthrene and pyrene alone, Rhodococcus sp. 20, Rhodococcus sp. 016, A. tucumanensis DSM 45259, Streptomyces sp. A2, and Streptomyces sp. A12 were challenged to an adaptation schedule of successive cultures on a fresh solid medium supplemented with PAHs, decreasing concentration of glucose in each step. As a result, an enhanced degradation of PAHs by adapted strains was observed in the presence of glucose as co-substrate, without degradation of phenanthrene and pyrene in MM while an increase to up to 50% of degradation was seen with these strains in glucose amended media. An internal fragment of the catA gene, which codes for catechol 1,2-dioxygenase, was amplified from both Rhodococcus strains, showing the potential for degradation of aromatic compounds via salycilate. These results allow us to propose the usefulness of these actinomycete strains for PAH bioremediation in the environment. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evidence for an amoeba-like infectious stage of ichthyophonus sp. and description of a circulating blood stage: a probable mechanism for dispersal within the fish host

USGS Publications Warehouse

Kocan, Richard; LaPatra, Scott; Hershberger, Paul

2013-01-01

Small amoeboid cells, believed to be the infectious stage of Ichthyophonus sp., were observed in the bolus (stomach contents) and tunica propria (stomach wall) of Pacific staghorn sculpins and rainbow trout shortly after they ingested Ichthyophonus sp.–infected tissues. By 24–48 hr post-exposure (PE) the parasite morphed from the classically reported multinucleate thick walled schizonts to 2 distinct cell types, i.e., a larger multinucleate amoeboid cell surrounded by a narrow translucent zone and a smaller spherical cell surrounded by a “halo” and resembling a small schizont. Both cell types also appeared in the tunica propria, indicating that they had recently penetrated the columnar epithelium of the stomach. No Ichthyophonus sp. pseudo-hyphae (“germination tubes”) were observed in the bolus or penetrating the stomach wall. Simultaneously, Ichthyophonus sp. was isolated in vitro from aortic blood, which was consistently positive from 6 to 144 hr PE, then only intermittently for the next 4 wk. Small PAS-positive cells observed in blood cultures grew into colonies consisting of non-septate tubules (pseudo-hyphae) terminating in multinucleated knob-like apices similar to those seen in organ explant cultures. Organ explants were culture positive every day; however, typical Ichthyophonus sp. schizonts were not observed histologically until 20–25 days PE. From 20 to 60 days PE, schizont diameter increased from ≤25 μm to ≥82 μm. Based on the data presented herein, we are confident that we have resolved the life cycle of Ichthyophonus sp. within the piscivorous host.

Mixed submerged fermentation with two filamentous fungi for cellulolytic and xylanolytic enzyme production.

PubMed

Garcia-Kirchner, O; Muñoz-Aguilar, M; Pérez-Villalva, R; Huitrón-Vargas, C

2002-01-01

The efficient saccharification of lignocellulosic materials requires the cooperative actions of different cellulase enzyme activities: exoglucanase, endoglucanase, beta-glucosidase, and xylanase. Previous studies with the fungi strains Aureobasidium sp. CHTE-18, Penicillium sp. CH-TE-001, and Aspergillus terreus CH-TE-013, selected mainly because of their different cellulolytic and xylanolytic activities, have demonstrated the capacity of culture filtrates of cross-synergistic action in the saccharification of native sugarcane bagasse pith. In an attempt to improve the enzymatic hydrolysis of different cellulosic materials, we investigated a coculture fermentation with two of these strains to enhance the production of cellulases and xylanases. The 48-h batch experimental results showed that the mixed culture of Penicillium sp. CH-TE-001 and A. terreus CH-TE-013 produced culture filtrates with high protein content, cellulase (mainly beta-glucosidase), and xylanase activities compared with the individual culture of each strain. The same culture conditions were used in a simple medium with mineral salts, corn syrup liquor, and sugarcane bagasse pith as the sole carbon source with moderate shaking at 29 degrees C. Finally, we compared the effect of the cell-free culture filtrates obtained from the mixed and single fermentations on the saccharification of different kinds of cellulosic materials.

Enhancement of palmarumycin C12 and C13 production in liquid culture of the endophytic fungus Berkleasmium sp. Dzf12 by oligosaccharides from its host plant Dioscorea zingiberensis.

PubMed

Li, Yan; Shan, Tijiang; Mou, Yan; Li, Peiqin; Zhao, Jianglin; Zhao, Wensheng; Peng, Youliang; Zhou, Ligang; Ding, Chunbang

2012-03-26

Three crude oligosaccharides were respectively prepared by acid hydrolysis of three polysaccharides, which were water-extracted polysaccharide (WEP), sodium hydroxide-extracted polysaccharide (SEP) and acid-extracted polysaccharide (AEP) from the rhizomes of Dioscorea zingiberensis. Among the three oligosaccharides, the crude oligosaccharide prepared by acid hydrolysis of WEP was found to be the most efficient elicitor to enhance the production of palmarumycins C(12) and C(13) in liquid culture of endophytic fungus Berkleasmium sp. Dzf12. When OW was applied to the medium at 300 mg/L on day 3 of culture, the maximal yields of palmarumycin C(12) (87.96 mg/L) and palmarumycin C(13) (422.28 mg/L) were achieved on day 15 of culture, which were 9.83 and 3.24-fold in comparison with those (8.95 and 130.43 mg/L) of control, respectively. The results indicate that addition of the oligosaccharides from the host plant D. zingiberensis should be an effective strategy for enhancing production of palmarumycins C(12) and C(13) in liquid culture of endophytic fungus Berkleasmium sp. Dzf12.

Laccase production by Monotospora sp., an endophytic fungus in Cynodon dactylon.

PubMed

Wang, J W; Wu, J H; Huang, W Y; Tan, R X

2006-03-01

The effects of the carbon and nitrogen sources, initial pH and incubation temperature on laccase production by the endophytic fungus Monotospora sp. were evaluated. The optimal temperature and initial pH for laccase production by Monotospora sp. in submerged culture were found to be 30 degrees C and 8.5, respectively. Maltose (2 g l(-1)) and ammonium tartrate (10 g l(-1)) were the most suitable carbon and nitrogen source for laccase production. Under optimal culture medium, the maximum laccase activity was determined to be 13.55 U ml(-1), which was approximately four times higher than that in basal medium. This is the first report on laccase production by an endophytic fungus.

Viruses Infecting a Freshwater Filamentous Cyanobacterium (Nostoc sp.) Encode a Functional CRISPR Array and a Proteobacterial DNA Polymerase B.

PubMed

Chénard, Caroline; Wirth, Jennifer F; Suttle, Curtis A

2016-06-14

Here we present the first genomic characterization of viruses infecting Nostoc, a genus of ecologically important cyanobacteria that are widespread in freshwater. Cyanophages A-1 and N-1 were isolated in the 1970s and infect Nostoc sp. strain PCC 7210 but remained genomically uncharacterized. Their 68,304- and 64,960-bp genomes are strikingly different from those of other sequenced cyanophages. Many putative genes that code for proteins with known functions are similar to those found in filamentous cyanobacteria, showing a long evolutionary history in their host. Cyanophage N-1 encodes a CRISPR array that is transcribed during infection and is similar to the DR5 family of CRISPRs commonly found in cyanobacteria. The presence of a host-related CRISPR array in a cyanophage suggests that the phage can transfer the CRISPR among related cyanobacteria and thereby provide resistance to infection with competing phages. Both viruses also encode a distinct DNA polymerase B that is closely related to those found in plasmids of Cyanothece sp. strain PCC 7424, Nostoc sp. strain PCC 7120, and Anabaena variabilis ATCC 29413. These polymerases form a distinct evolutionary group that is more closely related to DNA polymerases of proteobacteria than to those of other viruses. This suggests that the polymerase was acquired from a proteobacterium by an ancestral virus and transferred to the cyanobacterial plasmid. Many other open reading frames are similar to a prophage-like element in the genome of Nostoc sp. strain PCC 7524. The Nostoc cyanophages reveal a history of gene transfers between filamentous cyanobacteria and their viruses that have helped to forge the evolutionary trajectory of this previously unrecognized group of phages. Filamentous cyanobacteria belonging to the genus Nostoc are widespread and ecologically important in freshwater, yet little is known about the genomic content of their viruses. Here we report the first genomic analysis of cyanophages infecting filamentous freshwater cyanobacteria, revealing that their gene content is unlike that of other cyanophages. In addition to sharing many gene homologues with freshwater cyanobacteria, cyanophage N-1 encodes a CRISPR array and expresses it upon infection. Also, both viruses contain a DNA polymerase B-encoding gene with high similarity to genes found in proteobacterial plasmids of filamentous cyanobacteria. The observation that phages can acquire CRISPRs from their hosts suggests that phages can also move them among hosts, thereby conferring resistance to competing phages. The presence in these cyanophages of CRISPR and DNA polymerase B sequences, as well as a suite of other host-related genes, illustrates the long and complex evolutionary history of these viruses and their hosts. Copyright © 2016 Chénard et al.

Influence of endogenous and exogenous electron donors and trichloroethylene oxidation toxicity on trichloroethylene oxidation by methanotrophic cultures from a groundwater aquifer.

PubMed Central

Henry, S M; Grbić-Galić, D

1991-01-01

Trichloroethylene (TCE)-transforming aquifer methanotrophs were evaluated for the influence of TCE oxidation toxicity and the effect of reductant availability on TCE transformation rates during methane starvation. TCE oxidation at relatively low (6 mg liter-1) TCE concentrations significantly reduced subsequent methane utilization in mixed and pure cultures tested and reduced the number of viable cells in the pure culture Methylomonas sp. strain MM2 by an order of magnitude. Perchloroethylene, tested at the same concentration, had no effect on the cultures. Neither the TCE itself nor the aqueous intermediates were responsible for the toxic effect, and it is suggested that TCE oxidation toxicity may have resulted from reactive intermediates that attacked cellular macromolecules. During starvation, all methanotrophs tested exhibited a decline in TCE transformation rates, and this decline followed exponential decay. Formate, provided as an exogenous electron donor, increased TCE transformation rates in Methylomonas sp. strain MM2, but not in mixed culture MM1 or unidentified isolate, CSC-1. Mixed culture MM2 did not transform TCE after 15 h of starvation, but mixed cultures MM1 and MM3 did. The methanotrophs in mixed cultures MM1 and MM3, and the unidentified isolate CSC-1 that was isolated from mixed culture MM1 contained lipid inclusions, whereas the methanotrophs of mixed culture MM2 and Methylomonas sp. strain MM2 did not. It is proposed that lipid storage granules serve as an endogenous source of electrons for TCE oxidation during methane starvation. Images PMID:2036010

Microbial activity of trench leachates from shallow-land, low-level radioactive waste disposal sites.

PubMed Central

Francis, A J; Dobbs, S; Nine, B J

1980-01-01

Trench leachate samples collected anoxically from shallow-land, low-level radioactive waste disposal sites were analyzed for total aerobic and anaerobic populations, sulfate reducers, denitrifiers, and methanogens. Among the several aerobic and anaerobic bacteria isolated, only Bacillus sp., Pseudomonas sp., Citrobacter sp., and Clostridium sp. were identified. Mixed bacterial cultures isolated from the trench leachates were able to grow anaerobically in trench leachates, which indicates that the radionuclides and organic chemicals present were not toxic to these bacteria. Changes in concentrations of several of the organic constituents of the waste leachate samples were observed due to anaerobic microbial activity. Growth of a mixed culture of trench-water bacteria in media containing a mixture of radionuclides, 60Co, 85Sr, and 134,137Cs, was not affected at total activity concentrations of 2.6 X 10(2) and 2.7 X 10(3) pCi/ml. PMID:7406490

Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria.

PubMed

da Silva, Fábio Daniel Florêncio; Lima, Alex Ranieri Jerônimo; Moraes, Pablo Henrique Gonçalves; Siqueira, Andrei Santos; Dall'Agnol, Leonardo Teixeira; Baraúna, Anna Rafaella Ferreira; Martins, Luisa Carício; Oliveira, Karol Guimarães; de Lima, Clayton Pereira Silva; Nunes, Márcio Roberto Teixeira; Vianez-Júnior, João Lídio Silva Gonçalves; Gonçalves, Evonnildo Costa

2016-05-19

Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here. Copyright © 2016 da Silva et al.

Isolation and evaluation of potent Pseudomonas species for bioremediation of phorate in amended soil.

PubMed

Jariyal, Monu; Gupta, V K; Jindal, Vikas; Mandal, Kousik

2015-12-01

Use of phorate as a broad spectrum pesticide in agricultural crops is finding disfavor due to persistence of both the principal compound as well as its toxic residues in soil. Three phorate utilizing bacterial species (Pseudomonas sp. strain Imbl 4.3, Pseudomonas sp. strain Imbl 5.1, Pseudomonas sp. strain Imbl 5.2) were isolated from field soils. Comparative phorate degradation analysis of these species in liquid cultures identified Pseudomonas sp. strain Imbl 5.1 to cause complete metabolization of phorate during seven days as compared to the other two species in 13 days. In soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil), Pseudomonas sp. strain Imbl 5.1 resulted in active metabolization of phorate by between 94.66% and 95.62% establishing the same to be a potent bacterium for significantly relieving soil from phorate residues. Metabolization of phorate to these phorate residues did not follow the first order kinetics. This study proves that Pseudomonas sp. strain Imbl 5.1 has huge potential for active bioremediation of phorate both in liquid cultures and agricultural soils. Copyright © 2015 Elsevier Inc. All rights reserved.

In vitro generation of type-II pneumocytes can be initiated in human CD34(+) stem cells.

PubMed

Srikanth, Lokanathan; Venkatesh, Katari; Sunitha, Manne Mudhu; Kumar, Pasupuleti Santhosh; Chandrasekhar, Chodimella; Vengamma, Bhuma; Sarma, Potukuchi Venkata Gurunadha Krishna

2016-02-01

Human CD34(+) stem cells differentiated into type-II pneumocytes in Dulbecco's modified Eagle medium (DMEM) having hydrocortisone, insulin, fibroblast growth factor (FGF), epidermal growth factor (EGF) and bovine serum albumin (BSA), expressing surfactant proteins-B (SP-B) and C (SP-C), alkaline phosphatase (ALP) and lysozyme. FACS-enumerated pure CD34(+) cells, isolated from human peripheral blood, were cultured in DMEM and showed positive reaction with anti-human CD34 monoclonal antibodies in immunocytochemistry. These cells were cultured in DMEM having hydrocortisone, insulin, FGF, EGF and BSA (HIFEB-D) medium having an air-liquid interface. They differentiated into type-II pneumocytes with expression of SP-B and SP-C genes and disappearance of CD34 expression as assessed using real-time PCR. In reverse transcription-PCR amplicons showed 208 and 907 bp confirming SP-B and SP-C expressions. These cells expressed ALP with an activity of 1.05 ± 0.09 mM ml(-1) min(-1) and lysozyme that killed E. coli. The successful differentiation of human CD34(+) stem cells into type-II pneumocytes, and transplantation of such cells obtained from the patient's stem cell could be the futuristic approach to regenerate diseased lung alveoli.

Differences in nutrient uptake capacity of the benthic filamentous algae Cladophora sp., Klebsormidium sp. and Pseudanabaena sp. under varying N/P conditions.

PubMed

Liu, Junzhuo; Vyverman, Wim

2015-03-01

The N/P ratio of wastewater can vary greatly and directly affect algal growth and nutrient removal process. Three benthic filamentous algae species Cladophora sp., Klebsormidium sp. and Pseudanabaena sp. were isolated from a periphyton bioreactor and cultured under laboratory conditions on varying N/P ratios to determine their ability to remove nitrate and phosphorus. The N/P ratio significantly influenced the algal growth and phosphorus uptake process. Appropriate N/P ratios for nitrogen and phosphorus removal were 5-15, 7-10 and 7-20 for Cladophora sp., Klebsormidium sp. and Pseudanabaena sp., respectively. Within these respective ranges, Cladophora sp. had the highest biomass production, while Pseudanabaena sp. had the highest nitrogen and phosphorus contents. This study indicated that Cladophora sp. had a high capacity of removing phosphorus from wastewaters of low N/P ratio, and Pseudanabaena sp. was highly suitable for removing nitrogen from wastewaters with high N/P ratio. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparative characterization of novel ene-reductases from cyanobacteria.

PubMed

Fu, Yilei; Castiglione, Kathrin; Weuster-Botz, Dirk

2013-05-01

The growing importance of biocatalysis in the syntheses of enantiopure molecules results from the benefits of enzymes regarding selectivity and specificity of the reaction and ecological issues of the process. Ene-reductases (ERs) from the old yellow enzyme family have received much attention in the last years. These flavo-enzymes catalyze the trans-specific reduction of activated C=C bonds, which is an important reaction in asymmetric synthesis, because up to two stereogenic centers can be created in one reaction. However, limitations of ERs described in the literature such as their moderate catalytic activity and their strong preference for NADPH promote the search for novel ERs with improved properties. In this study, we characterized nine novel ERs from cyanobacterial strains belonging to different taxonomic orders and habitats. ERs were identified with activities towards a broad spectrum of alkenes. The reduction of maleimide was catalyzed with activities of up to 35.5 U mg(-1) using NADPH. Ketoisophorone and (R)-carvone, which were converted to the highly valuable compounds (R)-levodione and (2R,5R)-dihydrocarvone, were reduced with reaction rates of up to 2.2 U mg(-1) with NADPH. In contrast to other homologous ERs from the literature, NADH was accepted at moderate to high rates as well: Enzyme activities of up to 16.7 U mg(-1) were obtained for maleimide and up to 1.3 U mg(-1) for ketoisophorone and (R)-carvone. Additionally, excellent stereoselectivities were achieved in the reduction of (R)-carvone (97-99% de). In particular, AnabaenaER3 from Anabaena variabilis ATCC 29413 and AcaryoER1 from Acaryochloris marina MBIC 11017 were identified as useful biocatalysts. Therefore, novel ERs from cyanobacteria with high catalytic efficiency were added to the toolbox for the asymmetric reduction of alkenes. Copyright © 2012 Wiley Periodicals, Inc.

Sucrose biosynthesis in a prokaryotic organism: Presence of two sucrose-phosphate synthases in Anabaena with remarkable differences compared with the plant enzymes

PubMed Central

Porchia, Andrea C.; Salerno, Graciela L.

1996-01-01

Biosynthesis of sucrose-6-P catalyzed by sucrose-phosphate synthase (SPS), and the presence of sucrose-phosphate phosphatase (SPP) leading to the formation of sucrose, have both been ascertained in a prokaryotic organism: Anabaena 7119, a filamentous heterocystic cyanobacterium. Two SPS activities (SPS-I and SPS-II) were isolated by ion-exchange chromatography and partially purified. Four remarkable differences between SPSs from Anabaena and those from higher plants were shown: substrate specificity, effect of divalent cations, native molecular mass, and oligomeric composition. Both SPS-I and SPS-II accept Fru-6-P (Km for SPS-I = 0.8 ± 0.1 mM; Km for SPS-II = 0.7 ± 0.1 mM) and UDP-Glc as substrates (Km for SPS-I = 1.3 ± 0.4 mM; Km for SPS-II = 4.6 ± 0.4 mM), but unlike higher plant enzymes, they are not specific for UDP-Glc. GDP-Glc and TDP-Glc are also SPS-I substrates (Km for GDP-Glc = 1.2 ± 0.2 mM and Km for TDP-Glc = 4.0 ± 0.4 mM), and ADP-Glc is used by SPS-II (Km for ADP-Glc = 5.7 ± 0.7 mM). SPS-I has an absolute dependence toward divalent metal ions (Mg2+ or Mn2+) for catalytic activity, not found in plants. A strikingly smaller native molecular mass (between 45 and 47 kDa) was determined by gel filtration for both SPSs, which, when submitted to SDS/PAGE, showed a monomeric composition. Cyanobacteria are, as far as the authors know, the most primitive organisms that are able to biosynthesize sucrose as higher plants do. PMID:8942980

Phylogeography of Cylindrospermopsin and Paralytic Shellfish Toxin-Producing Nostocales Cyanobacteria from Mediterranean Europe (Spain)

PubMed Central

Cirés, Samuel; Wörmer, Lars; Ballot, Andreas; Agha, Ramsy; Wiedner, Claudia; Velázquez, David; Casero, María Cristina

2014-01-01

Planktonic Nostocales cyanobacteria represent a challenge for microbiological research because of the wide range of cyanotoxins that they synthesize and their invasive behavior, which is presumably enhanced by global warming. To gain insight into the phylogeography of potentially toxic Nostocales from Mediterranean Europe, 31 strains of Anabaena (Anabaena crassa, A. lemmermannii, A. mendotae, and A. planctonica), Aphanizomenon (Aphanizomenon gracile, A. ovalisporum), and Cylindrospermopsis raciborskii were isolated from 14 freshwater bodies in Spain and polyphasically analyzed for their phylogeography, cyanotoxin production, and the presence of cyanotoxin biosynthesis genes. The potent cytotoxin cylindrospermopsin (CYN) was produced by all 6 Aphanizomenon ovalisporum strains at high levels (5.7 to 9.1 μg CYN mg−1 [dry weight]) with low variation between strains (1.5 to 3.9-fold) and a marked extracellular release (19 to 41% dissolved CYN) during exponential growth. Paralytic shellfish poisoning (PSP) neurotoxins (saxitoxin, neosaxitoxin, and decarbamoylsaxitoxin) were detected in 2 Aphanizomenon gracile strains, both containing the sxtA gene. This gene was also amplified in non-PSP toxin-producing Aphanizomenon gracile and Aphanizomenon ovalisporum. Phylogenetic analyses supported the species identification and confirmed the high similarity of Spanish Anabaena and Aphanizomenon strains with other European strains. In contrast, Cylindrospermopsis raciborskii from Spain grouped together with American strains and was clearly separate from the rest of the European strains, raising questions about the current assumptions of the phylogeography and spreading routes of C. raciborskii. The present study confirms that the nostocalean genus Aphanizomenon is a major source of CYN and PSP toxins in Europe and demonstrates the presence of the sxtA gene in CYN-producing Aphanizomenon ovalisporum. PMID:24334673

Phylogeography of cylindrospermopsin and paralytic shellfish toxin-producing nostocales cyanobacteria from mediterranean europe (Spain).

PubMed

Cirés, Samuel; Wörmer, Lars; Ballot, Andreas; Agha, Ramsy; Wiedner, Claudia; Velázquez, David; Casero, María Cristina; Quesada, Antonio

2014-02-01

Planktonic Nostocales cyanobacteria represent a challenge for microbiological research because of the wide range of cyanotoxins that they synthesize and their invasive behavior, which is presumably enhanced by global warming. To gain insight into the phylogeography of potentially toxic Nostocales from Mediterranean Europe, 31 strains of Anabaena (Anabaena crassa, A. lemmermannii, A. mendotae, and A. planctonica), Aphanizomenon (Aphanizomenon gracile, A. ovalisporum), and Cylindrospermopsis raciborskii were isolated from 14 freshwater bodies in Spain and polyphasically analyzed for their phylogeography, cyanotoxin production, and the presence of cyanotoxin biosynthesis genes. The potent cytotoxin cylindrospermopsin (CYN) was produced by all 6 Aphanizomenon ovalisporum strains at high levels (5.7 to 9.1 μg CYN mg(-1) [dry weight]) with low variation between strains (1.5 to 3.9-fold) and a marked extracellular release (19 to 41% dissolved CYN) during exponential growth. Paralytic shellfish poisoning (PSP) neurotoxins (saxitoxin, neosaxitoxin, and decarbamoylsaxitoxin) were detected in 2 Aphanizomenon gracile strains, both containing the sxtA gene. This gene was also amplified in non-PSP toxin-producing Aphanizomenon gracile and Aphanizomenon ovalisporum. Phylogenetic analyses supported the species identification and confirmed the high similarity of Spanish Anabaena and Aphanizomenon strains with other European strains. In contrast, Cylindrospermopsis raciborskii from Spain grouped together with American strains and was clearly separate from the rest of the European strains, raising questions about the current assumptions of the phylogeography and spreading routes of C. raciborskii. The present study confirms that the nostocalean genus Aphanizomenon is a major source of CYN and PSP toxins in Europe and demonstrates the presence of the sxtA gene in CYN-producing Aphanizomenon ovalisporum.

Chytridiomycosis of Marine Diatoms-The Role of Stress Physiology and Resistance in Parasite-Host Recognition and Accumulation of Defense Molecules.

PubMed

Scholz, Bettina; Küpper, Frithjof C; Vyverman, Wim; Ólafsson, Halldór G; Karsten, Ulf

2017-01-25

Little is known about the role of chemotaxis in the location and attachment of chytrid zoospores to potential diatom hosts. Hypothesizing that environmental stress parameters affect parasite-host recognition, four chytrid-diatom tandem cultures ( Chytridium sp./ Navicula sp., Rhizophydium type I/ Nitzschia sp., Rhizophydium type IIa/ Rhizosolenia sp., Rhizophydium type IIb/ Chaetoceros sp.) were used to test the chemotaxis of chytrid zoospores and the presence of potential defense molecules in a non-contact-co-culturing approach. As potential triggers in the chemotaxis experiments, standards of eight carbohydrates, six amino acids, five fatty acids, and three compounds known as compatible solutes were used in individual and mixed solutions, respectively. In all tested cases, the whole-cell extracts of the light-stressed (continuous light exposure combined with 6 h UV radiation) hosts attracted the highest numbers of zoospores (86%), followed by the combined carbohydrate standard solution (76%), while all other compounds acted as weak triggers only. The results of the phytochemical screening, using biomass and supernatant extracts of susceptible and resistant host-diatom cultures, indicated in most of the tested extracts the presence of polyunsaturated fatty acids, phenols, and aldehydes, whereas the bioactivity screenings showed that the zoospores of the chytrid parasites were only significantly affected by the ethanolic supernatant extract of the resistant hosts.

Microflora of black and red pepper.

PubMed

Christensen, C M; Fanse, H A; Nelson, G H; Bates, F; Mirocha, C J

1967-05-01

Dilution cultures of 30 samples of ground black pepper yielded an average of 39,000 colonies of fungi per g, with a range of 1,700 to 310,000 per g. Total numbers of colonies of bacteria from 11 samples averaged 194,000,000 per g, with a range from 8,300,000 to 704,000,000 per g. A variety of fungi grew from nearly all surface-disinfected whole peppercorns that were cultured. Thirteen samples of ground red pepper from the United States yielded an average of 1,600 colonies of storage fungi per g and an equal number of other fungi; five samples from India yielded an average of 78,900 colonies of storage fungi per g and 169,400 colonies of other fungi per g. Among the fungi from both black and red pepper were Aspergillus flavus and A. ochraceus, some isolates of which, when grown for 8 to 10 days on moist autoclaved corn and fed to white rats or to 2-day-old Pekin ducklings, were rapidly lethal to them. Aflatoxin B(1) was isolated from one of the samples of corn on which A. flavus from black pepper was grown. Among the bacteria isolated from ground black pepper were Escherichia coli, E. freudii, Serratia sp., Klebsiella sp., Bacillus sp., Staphylococcus sp., and Streptococcus sp. No cultures of Shigella or Salmonella were found.

Three new drimane sesquiterpenoids from cultures of the fungus Penicillium sp.

PubMed

Ding, Jian-Hai; Ding, Zhang-Gui; Chunyu, Wei-Xun; Zhao, Jiang-Yuan; Wang, Hai-Bin; Liu, Shi-Wei; Wang, Fei

2017-08-01

Three new drimane sesquiterpenoids, 12-hydroxyalbrassitriol (1), drim-8(12)-en-6β,7α, 9α,11-tetraol (2), and drim-68(12)-dien-9α,11-diol (3), along with one known analog albrassitriol (4), were isolated from cultures of the tin mine tailings-associated fungus Penicillium sp. The new structures were determined on the basis of extensive spectroscopic analyses. All compounds were tested for their cytotoxicities against five human cancer cell lines.

[Pectolytic enzymes formed by Penicillium and Fusarium micromycetes].

PubMed

Devdariani, T G; Aĭzenberg, V L; Bilaĭ, T I; Zakordonets, L A; Mudzhiri, L A

1982-01-01

The ability of the two cultures Penicillium sp. and Fusarium sp. to synthesize extracellular pectolytic enzymes was investigated. The cultivation conditions providing a high level of the biosynthesis of these enzymes were identified. The methods of isolating the enzymes by means of organic solvents were developed. The pectinase from Penicillium sp. showed a higher thermostability whereas that from Fusarium sp. displayed a greater acid resistance. Using glutaraldehyde and titanium salts, active immobilized forms of pectinases on silica carriers were prepared.

Role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh.

PubMed

Islam, M Sirajul; Islam, M Shafiqul; Mahmud, Zahid H; Cairncross, Sandy; Clemens, John D; Collins, Andrew E

2015-09-01

In Bangladesh, cholera is endemic and maintains a regular seasonal pattern. The role of phytoplankton in maintaining endemicity and seasonality of cholera was monitored in Matlab, Bangladesh. Phytoplankton and water samples were collected from two ponds bi-weekly for 1 year. The association of Vibrio cholerae O1 with phytoplankton was studied by culture and direct fluorescent antibody techniques. The bio-physicochemical parameters of water were measured and data for cases of cholera were collected from the records of Matlab hospital. The correlation of cholera cases with levels of phytoplankton, V. cholerae and bio-physicochemical parameters of water was carried out using Pearson's correlation coefficients. V. cholerae O1 survived for 48 days in association with Anabaena variabilis in a culturable state, but survived for a year in a viable but non-culturable (VBNC) state. V. cholerae survived for 12 and 32 days in a culturable state in control water (without algae) and water with algae, respectively. There was a significant correlation between changing levels of cholera cases in the community and the blue green algae and total phytoplankton in the aquatic environment. A significant correlation was also found between the cholera cases and chlorophyll-a and VBNC V. cholerae O1 in the aquatic environment. This study demonstrated the role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Bacterial biodegradation of melamine-contaminated aged soil: influence of different pre-culture media or addition of activation material.

PubMed

Hatakeyama, Takashi; Takagi, Kazuhiro

2016-08-01

This study aimed to investigate the biodegrading potential of Arthrobacter sp. MCO, Arthrobacter sp. CSP, and Nocardioides sp. ATD6 in melamine-contaminated upland soil (melamine: approx. 10.5 mg/kg dry weight) after 30 days of incubation. The soil sample used in this study had undergone annual treatment of lime nitrogen, which included melamine; it was aged for more than 10 years in field. When R2A broth was used as the pre-culture medium, Arthrobacter sp. MCO could degrade 55 % of melamine after 30 days of incubation, but the other strains could hardly degrade melamine (approximately 25 %). The addition of trimethylglycine (betaine) in soil as an activation material enhanced the degradation rate of melamine by each strain; more than 50 % of melamine was degraded by all strains after 30 days of incubation. In particular, strain MCO could degrade 72 % of melamine. When the strains were pre-cultured in R2A broth containing melamine, the degradation rate of melamine in soil increased remarkably. The highest (72 %) melamine degradation rate was noted when strain MCO was used with betaine addition.

Descriptions of Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina) from Haryana, India.

PubMed

Tomar, V V S; Somvanshi, Vishal S; Bajaj, Harish K

2015-03-01

Two different nematodes were isolated from the bark of Albizia lebbeck trees; one from insect infested and another from noninfested, healthy tree. Based on the biological, morphological, and molecular evidences, the nematodes are described as Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina). Deladenus albizicus n. sp., isolated from insect-infested tree, multiplied on the fungus Nigrospora oryzae. Myceliophagous females of this nematode reproduced by parthenogenesis and spermathecae were indistinct. Infective females, readily produced in the cultures, are dorsally curved. Only one type of males containing small-sized sperms in their genital tracts were produced in the culture. Myceliophagous females: L = 0.75 to 1.71 mm, a = 32.3 to 50.8, b = 9.3 to 11.2, b' = 5.2 to 7.3, c = 27.2 to 35.6, V = 91.0 to 93.3, c' = 2.0 to 2.9, stylet = 11 to 12 µm, excretory pore in the region of median pharyngeal bulb, 43 to 47 µm anterior to hemizonid. Deladenus processus n. sp., isolated from bark of healthy A. lebbeck tree, was cultured on Alternaria alternata. Myceliophagous females reproduced by amphimixis and their spermathecae contained rounded sperms. Infective females were never produced, even in old cultures. Myceliophagous females: L = 0.76 to 0.99 mm, a = 34 to 49, b = 13.3 to 17.7, b' = 3.8 to 5.8, c = 19.6 to 22.8, V = 92.2 to 93.5, c' = 2.7 to 3.5, stylet = 6 to 7 µm, excretory pore in the proximity of hemizonid, tail conoid, tapering from both sides to a long pointed central process. It is proposed to classify Deladenus species in three groups: durus, siricidicola, and laricis groups based on female and spermatogonia dimorphism, mode of reproduction, and insect parasitism.

Descriptions of Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina) from Haryana, India

PubMed Central

Tomar, V. V. S.; Somvanshi, Vishal S.; Bajaj, Harish K.

2015-01-01

Two different nematodes were isolated from the bark of Albizia lebbeck trees; one from insect infested and another from noninfested, healthy tree. Based on the biological, morphological, and molecular evidences, the nematodes are described as Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina). Deladenus albizicus n. sp., isolated from insect-infested tree, multiplied on the fungus Nigrospora oryzae. Myceliophagous females of this nematode reproduced by parthenogenesis and spermathecae were indistinct. Infective females, readily produced in the cultures, are dorsally curved. Only one type of males containing small-sized sperms in their genital tracts were produced in the culture. Myceliophagous females: L = 0.75 to 1.71 mm, a = 32.3 to 50.8, b = 9.3 to 11.2, b’ = 5.2 to 7.3, c = 27.2 to 35.6, V = 91.0 to 93.3, c’ = 2.0 to 2.9, stylet = 11 to 12 µm, excretory pore in the region of median pharyngeal bulb, 43 to 47 µm anterior to hemizonid. Deladenus processus n. sp., isolated from bark of healthy A. lebbeck tree, was cultured on Alternaria alternata. Myceliophagous females reproduced by amphimixis and their spermathecae contained rounded sperms. Infective females were never produced, even in old cultures. Myceliophagous females: L = 0.76 to 0.99 mm, a = 34 to 49, b = 13.3 to 17.7, b’ = 3.8 to 5.8, c = 19.6 to 22.8, V = 92.2 to 93.5, c’ = 2.7 to 3.5, stylet = 6 to 7 µm, excretory pore in the proximity of hemizonid, tail conoid, tapering from both sides to a long pointed central process. It is proposed to classify Deladenus species in three groups: durus, siricidicola, and laricis groups based on female and spermatogonia dimorphism, mode of reproduction, and insect parasitism. PMID:25861116

A Cultural Resources Evaluation of the Pammel Creek Site (47Lc61): An Oneota Occupation at La Crosse, Wisconsin

DTIC Science & Technology

1984-05-01

1 1 chrysemys/Gratemys sp. 1 - Small turtle sp. 2 - Fishes Estimated Total Live Weipht(kg) Lepisosteus sp. 3 1 .5 Amia calva 1 1 - Esox sp. 1 1 .2...Amphib. Gastropods 4 4 Feature 3 Estimated Total Fishes Live Weight(kg) Amia calva 1 1 2.3 Ictaluridae 2 1 •9 Feature 4 4 Freshwater Mussels Quadrula...Remains by Feature Number of Elements MNI 6 F.9 (cont.) Estimated Total Fishes Live Weight(kg) Lepisosteus sp. 5 1 .5 Amia calva 3 - - Catosom6i ae 1

Endosulfan induced biochemical changes in nitrogen-fixing cyanobacteria.

PubMed

Kumar, Satyendra; Habib, Khalid; Fatma, Tasneem

2008-09-15

Pesticide contamination in aquatic ecosystem including paddy fields is a serious global environmental concern. Cyanobacteria are also affected by pesticides as non- target organism. For better exploitation of cyanobacteria as biofertiliser, it is indispensable to select tolerant strains along with understanding of their tolerance. Three cyanobacterial strains viz. Aulosira fertilissima, Anabaena variabilis and Nostoc muscorum were studied for their stress responses to an organochlorine pesticide 'endosulfan' with special reference to oxidative stress, role of proline and antioxidant enzymes in endosulfan induced free radical detoxification. Reduction in growth, photosynthetic pigments and carbohydrate of the test microorganisms were accompanied with increase in their total protein, proline, malondialdehye (MDA), superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) in higher endosulfan doses. Increased amount of MDA is indicative of formation of free radicals, while increased level of CAT, APX, SOD and proline indicated their involvement in free radical scavenging mechanism. In lower concentrations, test pesticide showed increase in photosynthetic pigments. Order of tolerance was Nostoc muscorum>Anabaena variabilis>Aulosira fertilissima.

Effect of mineral phosphates on growth and nitrogen fixation of diazotrophic cyanobacteria Anabaena variabilis and Westiellopsis prolifica.

PubMed

Yandigeri, Mahesh S; Yadav, Arvind K; Meena, Kamlesh Kumar; Pabbi, Sunil

2010-03-01

The nitrogen fixing cyanobacterial strains namely Anabaena variabilis (Nostocales, Nostocaceae) and Westiellopsis prolifica (Nostocales, Hapalosiphonaceae) were evaluated for their nitrogen fixation and growth potential in response to different concentrations (10, 20 and 30 mg P) of the alternate insoluble P-sources Mussorie Rock Phosphate and Tricalcium Phosphate. Distinct and significant intergeneric differences were observed with respect to nitrogen fixation measured as Acetylene Reduction Activity (ARA) and growth potential as soluble proteins, total carbohydrate content, dry weight and total chlorophyll content in response to different concentrations of Mussorie Rock Phosphate and Tricalcium Phosphate. Both the strains showed higher soluble protein content at 20 mg P (Mussorie Rock Phosphate) that increased with time of incubation in A. variabilis. Both cyanobacteria recorded maximum Acetylene Reduction Activity at 20 mg P (Tricalcium Phosphate) followed by activity in presence of soluble phosphate (K2HPO4). The mean activity at all concentrations of insoluble phosphate (Mussorie Rock Phosphate and Tricalcium Phosphate) was more than in the presence of soluble phosphate.

Advanced solid-state NMR techniques for characterization of membrane protein structure and dynamics: Application to Anabaena Sensory Rhodopsin

NASA Astrophysics Data System (ADS)

Ward, Meaghan E.; Brown, Leonid S.; Ladizhansky, Vladimir

2015-04-01

Studies of the structure, dynamics, and function of membrane proteins (MPs) have long been considered one of the main applications of solid-state NMR (SSNMR). Advances in instrumentation, and the plethora of new SSNMR methodologies developed over the past decade have resulted in a number of high-resolution structures and structural models of both bitopic and polytopic α-helical MPs. The necessity to retain lipids in the sample, the high proportion of one type of secondary structure, differential dynamics, and the possibility of local disorder in the loop regions all create challenges for structure determination. In this Perspective article we describe our recent efforts directed at determining the structure and functional dynamics of Anabaena Sensory Rhodopsin, a heptahelical transmembrane (7TM) protein. We review some of the established and emerging methods which can be utilized for SSNMR-based structure determination, with a particular focus on those used for ASR, a bacterial protein which shares its 7TM architecture with G-protein coupled receptors.

Na(+) regulation by combined nitrogen in Azolla pinnata-Anabaena azollae symbiotic association during salt toxicity.

PubMed

Singh, Satya S; Singh, Santosh K; Mishra, Arun K

2008-01-01

To study the regulation of Na(+) ion by combined-N sources in Azolla pinnata-Anabaena azollae, Na(+) influx, intracellular Na(+) and Na(+) efflux were investigated in the presence of different N-sources (N(2), NH(4)(+), NO(3)(-) and urea) and various NaCl concentrations. Sodium influx by Azolla pinnata fronds was minimum in the presence of NO(3)(-). Almost identical levels of intracellular sodium, although less than N(2) and NH(4)(+) incubated fronds were observed in the presence of NO(3)(-) and urea. Efflux of sodium was minimum in urea and NO(3)(-) grown fronds. A low residual sodium was observed in the fronds incubated in NO(3)(-) and urea supplemented media. Results suggest that nitrate and urea curtailed the entry of sodium, reduced salt toxicity maximally by maintaining the minimum level of sodium and also conserved energy due to slow influx and efflux of Na(+) within the fronds during salt shock and the process of adaptation.

[Characterisation of Candida sp. isolated from patients after abdominal surgery].

PubMed

Adámková, V; Vaňková, A; Ulrych, J; Matek, K

2017-01-01

Intraabdominal candidiasis (IAC) is the predominant type of invasive candidiasis after candidemia. The majority of epidemiological studies on Candida are focused only on bloodstream infections. Nevertheless, the role of blood cultures has limited application in patients with abdominal candidiasis. IAC, which includes peritonitis and intraabdominal abscesses, may occur in around 40% of patients following repeat gastrointestinal (GI) surgery or GI perforation. Retrospective analysis of culture isolates of Candida sp. from clinical specimens of patients after abdominal surgery. The study period was from January 1 to October 31, 2016. Our study of 33 patients with findings of Candida sp. from the abdominal cavity found a mortality of 15.2%, the most frequent strain being C. albicans and C. glabrata. All strains of Candida sp. were susceptible to echinocandins. Candida sp. is part of normal microbiota of the gastrointestinal tract and its isolation is often difficult to interpret. Unfortunately, the pathophysiologic importance of Candida isolation from the abdominal space is not completely clear in many clinical situations.Key words: invasive candidiasis intra-abdominal candidiasis laboratory diagnostics.

Isolation, Identification, and Optimization of Culture Conditions of a Bioflocculant-Producing Bacterium Bacillus megaterium SP1 and Its Application in Aquaculture Wastewater Treatment

PubMed Central

Luo, Liang; Huang, Xiaoli; Du, Xue; Wang, Chang'an; Li, Jinnan; Wang, Liansheng

2016-01-01

A bioflocculant-producing bacterium, Bacillus megaterium SP1, was isolated from biofloc in pond water and identified by using both 16S rDNA sequencing analysis and a Biolog GEN III MicroStation System. The optimal carbon and nitrogen sources for Bacillus megaterium SP1 were 20 g L−1 of glucose and 0.5 g L−1 of beef extract at 30°C and pH 7. The bioflocculant produced by strain SP1 under optimal culture conditions was applied into aquaculture wastewater treatment. The removal rates of chemical oxygen demand (COD), total ammonia nitrogen (TAN), and suspended solids (SS) in aquaculture wastewater reached 64, 63.61, and 83.8%, respectively. The volume of biofloc (FV) increased from 4.93 to 25.97 mL L−1. The addition of Bacillus megaterium SP1 in aquaculture wastewater could effectively improve aquaculture water quality, promote the formation of biofloc, and then form an efficient and healthy aquaculture model based on biofloc technology. PMID:27840823

Scenedesmus sp. NJ-1 isolated from Antarctica: a suitable renewable lipid source for biodiesel production.

PubMed

Chen, Zhuo; Gong, Yangmin; Fang, Xiantao; Hu, Hanhua

2012-11-01

Microalgal lipids are promising alternative feedstocks for biodiesel production. Scenedesmus sp. NJ-1, an oil-rich freshwater microalga isolated from Antarctica, was identified to be a suitable candidate to produce biodiesel in this study. This strain could grow at temperatures ranging from 4 to 35 °C. With regular decrease in nitrate concentration in the medium, large quantities of triacylglycerols accumulated under batch culture conditions detected by thin layer chromatography and BODIPY 505/515 fluorescent staining. Scenedesmus sp. NJ-1 achieved the average biomass productivity of 0.105 g l⁻¹ d⁻¹ (dry weight) and nearly the highest lipid content (35 % of dry cell weight) was reached at day 28 in the batch culture. Neutral lipids accounted for 78 % of total lipids, and C18:1 (n-9), C16:0 were the major fatty acids in total lipids, composing 37 and 20 % of total fatty acids of Scenedesmus sp. NJ-1 grown for 36 days, respectively. These results suggested that Scenedesmus sp. NJ-1 was a good source of microalgal oils for biodiesel production.

In vitro differentiation of quail neural crest cells into sensory-like neuroblasts

NASA Technical Reports Server (NTRS)

Sieber-Blum, Maya; Kumar, Sanjiv R.; Riley, Danny A.

1988-01-01

Data are presented that demonstrate the ability of quail neural-crest embrionic cells grown as primary culture to differentiate in vitro into sensorylike neuroblasts. After 7-14 days of growth as primary culture, many of the putative sensory neuroblasts displayed substance P (SP)-like immunoreactivity and some exhibited histochemical carbonic anhydrase activity. Double staining experiments showed that the SP-like immunoreactive neuroblasts did not contain detectable levels of tyrosine hydroxylase or dopamine-beta-hydroxylase. The neuronal nature of the cultured sensorylike neuroblasts was further documented by double labeling for antibodies against the 68 kDa neurofilament polypeptide and substance P.

Idiopathic Granulomatous Mastitis Associated with Corynebacterium Sp. Infection

PubMed Central

Lee, Yun Sun; Balfour, John

2011-01-01

Idiopathic granulomatous mastitis (IGM) is a rare inflammatory condition of the breast. The etiology and treatments options of IGM remain controversial. Previous case reports have suggested that Corynebacterium sp., a gram-positive bacillus endogenous to the skin, may be associated with IGM. In the present report, we describe the first case of IGM with a positive culture for Corynebacterium sp. reported in the United States. PMID:21857740

Isolation of Potential Bacteria as Inoculum for Biofloc Formation in Pacific Whiteleg Shrimp, Litopenaeus vannamei Culture Ponds.

PubMed

Kasan, Nor Azman; Ghazali, Nurarina Ayuni; Ikhwanuddin, Mhd; Ibrahim, Zaharah

2017-01-01

A new green technology to reduce environmental damages while optimizing production of Pacific Whiteleg shrimp, Litopenaeus vannamei was developed known as "Biofloc technology". Microbial communities in biofloc aggregates are responsible in eliminating water exchange and producing microbial proteins that can be used as supplemented feed for L. vannamei. This study aimed to isolate and identify potential bioflocculant-producing bacteria to be used as inoculum for rapid formation of biofloc. For the purpose of this study, bacterial communities during 0, 30 and 70 days of culture (DOC) of L. vannamei grow-out ponds were isolated and identified through phenotypic and 16S rDNA sequences analysis. Phylogenetic relationships between isolated bacteria were then evaluated through phylogenetic tree analysis. One-way analysis of variance (ANOVA) was used to compare the differences of microbial communities at each DOC. Out of 125 bacterial isolates, nine species of bacteria from biofloc were identified successfully. Those bacteria species were identified as Halomonas venusta, H. aquamarina, Vibrio parahaemolyticus, Bacillus infantis, B. cereus, B. safensis, Providencia vermicola, Nitratireductor aquimarinus and Pseudoalteromonas sp., respectively. Through phylogenetic analysis, these isolates belong to Proteobacteria and Firmicutes families under the genera of Halomonas sp., Vibrio sp., Bacillus sp., Providencia sp., Nitratireductor sp. and Pseudoalteromonas sp. In this study, bioflocculant-producing bacteria were successfully identified which are perfect candidates in forming biofloc to reduce water pollution towards a sustainable aquaculture industry. Presence of Halomonas sp. and Bacillus sp. in all stages of biofloc formation reinforces the need for new development regarding the ability of these species to be used as inoculum in forming biofloc rapidly.

Bioremediation of Bisphenol A and Benzophenone by Glycosylation with Immobilized Marine Microalga Pavlova sp.

PubMed Central

Shimoda, Kei; Hamada, Hiroki

2009-01-01

Cultured cells of Pavlova sp. glycosylated bisphenol A to its mono-glucoside, 2-(4-β-D-glucopyranosyloxyphenyl)-2-hydroxyphenylpropane (9%). Use of immobilized Pavlova cells in sodium alginate gel improved yield of the product (17%). On the other hand, Pavlova cell cultures converted benzophenone into diphenylmethanol (49%) and diphenylmethyl β-D-glucopyranoside (6%). Incubation of benzophenone with immobilized Pavlova cells gave products in higher yields; the yields of diphenylmethanol and diphenylmethyl β-D-glucopyranoside were 85 and 15%, respectively. PMID:20508758

The novel gluconeogenesis inhibitors FR225659 and related compounds that originate from Helicomyces sp. No. 19353. I. Taxonomy, fermentation, isolation and physico-chemical properties.

PubMed

Ohtsu, Yoshihiro; Sasamura, Hiromi; Tsurumi, Yasuhisa; Yoshimura, Seiji; Takase, Shigehiro; Hashimoto, Michizane; Shibata, Toshihiro; Hino, Motohiro; Fujii, Takashi

2003-08-01

FR225659 and four related compounds are novel gluconeogenesis inhibitors that consist of a novel acyl-group and three abnormal amino acids. They were isolated from the culture broth of Helicomyces sp. No. 19353 and can be purified by absorptive resin and reverse-phase column chromatography. They are potent inhibitors of gluconeogenesis in primary cultured rat hepatocytes and thus may be useful as anti-diabetic agents.

Influence of agitation on the removal of nonylphenol by the white-rot fungi Trametes versicolor and Bjerkandera sp. BOL 13.

PubMed

Soares, Ana; Guieysse, Benoit; Mattiasson, Bo

2006-02-01

Bjerkandera sp. BOL 13 removed 95% of nonylphenol (at 9.7 mg nonylphenol L(-1) day(-1)) from aqueous medium after 5 days of incubation in agitated cultures. This removal rate decreased 2.5-fold in static cultures. By comparison, Trametes versicolor removed nonylphenol at 2.8 mg L(-1) day(-1) under conditions of static incubation, probably due to the action of laccase, but no growth was recorded in the agitated bottles.

Cyanobacterium sp. host cell and vector for production of chemical compounds in cyanobacterial cultures

DOEpatents

Piven, Irina; Friedrich, Alexandra; Duhring, Ulf; Uliczka, Frank; Baier, Kerstin; Inaba, Masami; Shi, Tuo; Wang, Kui; Enke, Heike; Kramer, Dan

2014-09-30

A cyanobacterial host cell, Cyanobacterium sp., that harbors at least one recombinant gene for the production of a chemical compounds is provided, as well as vectors derived from an endogenous plasmid isolated from the cell.

Cyanobacterium sp. host cell and vector for production of chemical compounds in Cyanobacterial cultures

DOEpatents

Piven, Irina; Friedrich, Alexandra; Duhring, Ulf; Uliczka, Frank; Baier, Kerstin; Inaba, Masami; Shi, Tuo; Wang, Kui; Enke, Heike; Kramer, Dan

2016-04-19

A cyanobacterial host cell, Cyanobacterium sp., that harbors at least one recombinant gene for the production of a chemical compounds is provided, as well as vectors derived from an endogenous plasmid isolated from the cell.

The dual regulation of substance P-mediated inflammation via human synovial mast cells in rheumatoid arthritis.

PubMed

Okamura, Yuki; Mishima, Shintaro; Kashiwakura, Jun-Ichi; Sasaki-Sakamoto, Tomomi; Toyoshima, Shota; Kuroda, Kazumichi; Saito, Shu; Tokuhashi, Yasuaki; Okayama, Yoshimichi

2017-09-01

Neural pathways are thought to be directly involved in the pathogenesis of rheumatoid arthritis (RA). Although synovial mast cells (MCs) are activated by substance P (SP), the role of MCs in neural pathways in RA remains unknown. The aims of this study were to investigate 1) whether tachykinins are produced by synovial MCs and whether production differs in RA and osteoarthritis (OA) patients, and 2) what is the responsible receptor for SP in synovial MCs. Synovial tissues were obtained from patients with RA or OA undergoing joint replacement surgery. Cultured synovium-derived MCs were generated by culturing dispersed synovial cells with stem cell factor. SP expression was investigated using immunofluorescence and enzyme immunoassays. Mas-related gene X2 (MrgX2) expression was reduced in human MCs using a lentiviral shRNA silencing technique. SP expression was localized around the cell membrane in 41% (median) of the MCs in synovium from RA but in only 7% of that from OA, suggesting the activation of MCs. Synovial MCs expressed tachykinin (TAC) 1 mRNA, the expression of which was upregulated by the aggregation of FcɛRI or the addition of aggregated IgG. However, the released SP appeared to be rapidly degraded by MC chymase. Synovial MCs were activated with SP through MrgX2 to release histamine without producing proinflammatory cytokines. Activated synovial MCs may rapidly degrade SP, which may downregulate the SP-mediated activation of synoviocytes in RA. On the other hand, SP activates MCs to induce inflammatory mediators, suggesting the dual regulation of SP-mediated inflammation by MCs in RA. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Upstream factors affecting Tualatin River algae—Tracking the 2008 Anabaena algae bloom to Wapato Lake, Oregon

USGS Publications Warehouse

Rounds, Stewart A.; Carpenter, Kurt D.; Fesler, Kristel J.; Dorsey, Jessica L.

2015-12-17

The results and insights derived from this study can be used to enhance future monitoring and data collection strategies designed to improve water quality and plankton models and better predict dissolved-oxygen concentrations in the lower Tualatin River.

Modeling the Relationship between Safety Climate and Safety Performance in a Developing Construction Industry: A Cross-Cultural Validation Study

PubMed Central

Zahoor, Hafiz; Chan, Albert P. C.; Utama, Wahyudi P.; Gao, Ran; Zafar, Irfan

2017-01-01

This study attempts to validate a safety performance (SP) measurement model in the cross-cultural setting of a developing country. In addition, it highlights the variations in investigating the relationship between safety climate (SC) factors and SP indicators. The data were collected from forty under-construction multi-storey building projects in Pakistan. Based on the results of exploratory factor analysis, a SP measurement model was hypothesized. It was tested and validated by conducting confirmatory factor analysis on calibration and validation sub-samples respectively. The study confirmed the significant positive impact of SC on safety compliance and safety participation, and negative impact on number of self-reported accidents/injuries. However, number of near-misses could not be retained in the final SP model because it attained a lower standardized path coefficient value. Moreover, instead of safety participation, safety compliance established a stronger impact on SP. The study uncovered safety enforcement and promotion as a novel SC factor, whereas safety rules and work practices was identified as the most neglected factor. The study contributed to the body of knowledge by unveiling the deviations in existing dimensions of SC and SP. The refined model is expected to concisely measure the SP in the Pakistani construction industry, however, caution must be exercised while generalizing the study results to other developing countries. PMID:28350366

Modeling the Relationship between Safety Climate and Safety Performance in a Developing Construction Industry: A Cross-Cultural Validation Study.

PubMed

Zahoor, Hafiz; Chan, Albert P C; Utama, Wahyudi P; Gao, Ran; Zafar, Irfan

2017-03-28

This study attempts to validate a safety performance (SP) measurement model in the cross-cultural setting of a developing country. In addition, it highlights the variations in investigating the relationship between safety climate (SC) factors and SP indicators. The data were collected from forty under-construction multi-storey building projects in Pakistan. Based on the results of exploratory factor analysis, a SP measurement model was hypothesized. It was tested and validated by conducting confirmatory factor analysis on calibration and validation sub-samples respectively. The study confirmed the significant positive impact of SC on safety compliance and safety participation , and negative impact on number of self-reported accidents/injuries . However, number of near-misses could not be retained in the final SP model because it attained a lower standardized path coefficient value. Moreover, instead of safety participation , safety compliance established a stronger impact on SP. The study uncovered safety enforcement and promotion as a novel SC factor, whereas safety rules and work practices was identified as the most neglected factor. The study contributed to the body of knowledge by unveiling the deviations in existing dimensions of SC and SP. The refined model is expected to concisely measure the SP in the Pakistani construction industry, however, caution must be exercised while generalizing the study results to other developing countries.

In Vitro Cultivation of 'Unculturable' Oral Bacteria, Facilitated by Community Culture and Media Supplementation with Siderophores.

PubMed

Vartoukian, Sonia R; Adamowska, Aleksandra; Lawlor, Megan; Moazzez, Rebecca; Dewhirst, Floyd E; Wade, William G

2016-01-01

Over a third of oral bacteria are as-yet-uncultivated in-vitro. Siderophores have been previously shown to enable in-vitro growth of previously uncultivated bacteria. The objective of this study was to cultivate novel oral bacteria in siderophore-supplemented culture media. Various compounds with siderophore activity, including pyoverdines-Fe-complex, desferricoprogen and salicylic acid, were found to stimulate the growth of difficult-to-culture strains Prevotella sp. HOT-376 and Fretibacterium fastidiosum. Furthermore, pyrosequencing analysis demonstrated increased proportions of the as-yet-uncultivated phylotypes Dialister sp. HOT-119 and Megasphaera sp. HOT-123 on mixed culture plates supplemented with siderophores. Therefore a culture model was developed, which incorporated 15 μg siderophore (pyoverdines-Fe-complex or desferricoprogen) or 150 μl neat subgingival-plaque suspension into a central well on agar plates that were inoculated with heavily-diluted subgingival-plaque samples from subjects with periodontitis. Colonies showing satellitism were passaged onto fresh plates in co-culture with selected helper strains. Five novel strains, representatives of three previously-uncultivated taxa (Anaerolineae bacterium HOT-439, the first oral taxon from the Chloroflexi phylum to have been cultivated; Bacteroidetes bacterium HOT-365; and Peptostreptococcaceae bacterium HOT-091) were successfully isolated. All novel isolates required helper strains for growth, implying dependence on a biofilm lifestyle. Their characterisation will further our understanding of the human oral microbiome.

Monoxenic liquid culture with Escherichia coli of the free-living nematode Panagrolaimus sp. (strain NFS 24-5), a potential live food candidate for marine fish and shrimp larvae.

PubMed

Ayub, Farhana; Seychelles, Laurent; Strauch, Olaf; Wittke, Martina; Ehlers, Ralf-Udo

2013-09-01

The free-living, bacterial-feeding nematode Panagrolaimus sp. (strain NFS 24-5) has potential for use as live food for marine shrimp and fish larvae. Mass production in liquid culture is a prerequisite for its commercial exploitation. Panagrolaimus sp. was propagated in monoxenic liquid culture on Escherichia coli and parameters, like nematode density, population dynamics and biomass were recorded and compared with life history table data. A mean maximum nematode density of 174,278 mL(-1) and a maximum of 251,000 mL(-1) were recorded on day 17 after inoculation. Highest average biomass was 40 g L(-1) at day 13. The comparison with life history table data indicated that the hypothetical potential of liquid culture is much higher than documented during this investigation. Nematode development is delayed in liquid culture and egg production per female is more than five times lower than reported from life history trait analysis. The latter assessed a nematode generation time of 7.1 days, whereas the process time at maximum nematode density in liquid culture was 16 days indicating that a reduction of the process time can be achieved by further investigating the influence of nematode inoculum density on population development. The results challenge future research to reduce process time and variability and improve population dynamics also during scale-up of the liquid culture process.

Assessing cultural competency skills in gastroenterology fellowship training.

PubMed

Balzora, Sophie; Abiri, Benjamin; Wang, Xiao-Jing; McKeever, James; Poles, Michael; Zabar, Sondra; Gillespie, Colleen; Weinshel, Elizabeth

2015-02-14

To assess and teach cultural competency skills at the fellowship training level through the use of objective structured clinical examinations (OSCEs). We revised four scenarios to infuse a specific focus on cross-cultural care, and to render them appropriate for gastroenterology fellows. Three are discussed here: (1) Poor Health Literacy; (2) Disclosing/Apologizing for a Complication to a Patient Who Mistrusts the Healthcare System; and (3) Breaking Bad News to a Fatalistic Patient. A fourth case emphasizing shared decision-making will be described elsewhere. Four stations were completed by fellows and observed live by four faculty members, and the fellows' performance was assessed. Eleven fellows from four programs participated in the four OSCE. In the "Poor Health Literacy" case, 18% (2/11) of participants recognized that the standardized patient (SP) had below-basic health literacy. None successfully evaluated the SP's reading skills in a culturally-sensitive manner. In "Disclosing/Apologizing for a Complication", 4/11 (36%) personally apologized for the complication. 1/11 recognized the SP's mistrust of the medical system. With "Breaking Bad News", 27% (3/11) explored the patient's values to identify her fatalistic beliefs. OSCEs can be used to assess deficiencies in culturally-competent care at the fellowship level. OSCEs also afford fellowships the opportunity to inform future training curricula.

Oil removal from petroleum sludge using bacterial culture with molasses substrate at temperature variation

NASA Astrophysics Data System (ADS)

Ni'matuzahroh, Puspitasari, Alvin Oktaviana; Pratiwi, Intan Ayu; Fatimah, Sumarsih, Sri; Surtiningsih, Tini; Salamun

2016-03-01

The study aims to reveal the potency of biosurfactant-producing bacterial culture with molasses as substrate growth in releasing oil from the petroleum sludge at temperature variations. Bacteria used consisted of (Acinetobacter sp. P2(1), Pseudomonas putida T1(8), Bacillus subtilis 3KP and Micrococcus sp. L II 61). The treatments were tested at 40°C, 50°C and 60 °C for 7 days of incubation. Synthetic surfactant (Tween 20) was used as a positive control and molasses as a negative control. Release of petroleum hydrocarbons from oil sludge was expressed in percentage of oil removal from oil sludge (%). Data were analyzed statistically using the Analysis of Variance (α = 0.05) and continued with Games-Howell test. The kinds of bacterial cultures, incubation temperature and combination of both affected the percentage of oil removal. The abilities of Bacillus subtilis 3KP and Micrococcus sp. LII 61cultures in oil removal from oil sludge at the temperature exposure of 60°C were higher than Tween 20. Both of bacterial cultures grown on molasses can be proposed as a replacement for synthetic surfactant to clean up the accumulation of oil sludge in a bottom of oil refinery tank.

Improvement of FK506 Production in the High-Yielding Strain Streptomyces sp. RM7011 by Engineering the Supply of Allylmalonyl-CoA Through a Combination of Genetic and Chemical Approach.

PubMed

Mo, SangJoon; Lee, Sung-Kwon; Jin, Ying-Yu; Suh, Joo-Won

2016-02-01

FK506, a widely used immunosuppressant, is a 23-membered polyketide macrolide that is produced by several Streptomyces species. FK506 high-yielding strain Streptomyces sp. RM7011 was developed from the discovered Streptomyces sp. KCCM 11116P by random mutagenesis in our previous study. The results of transcript expression analysis showed that the transcription levels of tcsA, B, C, and D were increased in Streptomyces sp. RM7011 by 2.1-, 3.1-, 3.3-, and 4.1- fold, respectively, compared with Streptomyces sp. KCCM 11116P. The overexpression of tcsABCD genes in Streptomyces sp. RM7011 gave rise to approximately 2.5-fold (238.1 μg/ml) increase in the level of FK506 production compared with that of Streptomyces sp. RM7011. When vinyl pentanoate was added into the culture broth of Streptomyces sp. RM7011, the level of FK506 production was approximately 2.2-fold (207.7 μg/ml) higher than that of the unsupplemented fermentation. Furthermore, supplementing the culture broth of Streptomyces sp. RM7011 expressing tcsABCD genes with vinyl pentanoate resulted in an additional 1.7-fold improvement in the FK506 titer (498.1 μg/ml) compared with that observed under nonsupplemented condition. Overall, the level of FK506 production was increased approximately 5.2-fold by engineering the supply of allylmalonyl-CoA in the high-yielding strain Streptomyces sp. RM7011, using a combination of overexpressing tcsABCD genes and adding vinyl pentanoate, as compared with Streptomyces sp. RM7011 (95.3 μg/ml). Moreover, among the three precursors analyzed, pentanoate was the most effective precursor, supporting the highest titer of FK506 in the FK506 high-yielding strain Streptomyces sp. RM7011.

Effects of soy peptone on the inoculum preparation of Streptococcus zooepidemicus for production of hyaluronic acid.

PubMed

Benedini, Leandro Junqueira; Santana, Maria Helena Andrade

2013-02-01

Soy peptone (SP) was studied as nutrient source in replacement of the conventional media as Brain-Heart Infusion (BHI) and sheep blood in the first seed culture medium in Petri plates of Streptococcus zooepidemicus. This substitution, aimed at meeting the claim of the pharmaceutical and cosmetics industries, for the removal of animal sources of the culture media used in obtaining their products for safety reasons. The animal sources were used as a control. The effects of this substitution were studied in fermentations carried out at 37°C and 150rpm in 250mL Erlenmeyer flasks containing 100mL culture medium containing glucose and SP only. The replacement of animal nutrient sources by SP to about twice the BHI concentration did not alter the amount of the produced HA, or caused deviations in the metabolism of the microorganism in favor of HA to the detriment of cell growth. Copyright © 2013 Elsevier Ltd. All rights reserved.

Metalaxyl Degradation by Mucorales Strains Gongronella sp. and Rhizopus oryzae.

PubMed

Martins, Maria Rosário; Santos, Cledir; Pereira, Pablo; Cruz-Morais, Júlio; Lima, Nelson

2017-12-14

In this study, the degradation of metalaxyl was investigated in the presence of two Mucorales strains, previously isolated from soil subjected to repeated treatments with this fungicide and selected after enrichment technique. Fungal strains were characterised by a polyphasic approach using phylogenetic analysis of the Internal Transcribed Spacer (ITS) gene region, phenotypic characterisation by Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) spectral analysis, and growth kinetics experiments. The strains were identified as Gongronella sp. and Rhizopus oryzae . The fungal growth kinetics in liquid cultures containing metalaxyl fits with Haldane model. Under laboratory conditions, the ability of Gongronella sp. and R. oryzae cultures to degrade metalaxyl was evaluated in liquid cultures and soil experiments. Both species were able to: (a) use metalaxyl as the main carbon and energy source; and (b) degrade metalaxyl in polluted soils, with rates around 1.0 mg kg - ¹ d - ¹. This suggests these strains could degrade metalaxyl in soils contaminated with this fungicide.

Genome Sequence of the Marine Janibacter Sp. Strain HTCC2649 ▿

PubMed Central

Thrash, J. Cameron; Cho, Jang-Cheon; Bertagnolli, Anthony D.; Ferriera, Steve; Johnson, Justin; Vergin, Kevin L.; Giovannoni, Stephen J.

2011-01-01

Janibacter sp. strain HTCC2649 is a novel marine member of the Actinobacteria, family Intrasporangiaceae, and is closely related to Janibacter melonis CM2104T and Knoellia sinensis HKI 0119T. The organism was isolated from a sample collected at Hydrostation S south of Bermuda by using high-throughput culturing techniques. Here we present the genome sequence of Janibacter sp. strain HTCC2649. PMID:21075932

Bioprospecting of Novel and Bioactive Compounds from Marine Actinomycetes Isolated from South China Sea Sediments.

PubMed

Yang, Na; Song, Fuhang

2018-02-01

Marine actinomycetes are less investigated compared to terrestrial strains as potential sources of natural products. To date, few investigations have been performed on culturable actinomycetes associated with South China Sea sediments. In the present study, twenty-eight actinomycetes were recovered from South China Sea sediments after dereplication by traditional culture-dependent method. The 16S rRNA gene sequences analyses revealed that these strains related to five families and seven genera. Twelve representative strains possessed at least one of the biosynthetic genes coding for polyketide synthase I, II, and nonribosomal peptide synthetase. Four strains had anti-Mycobacterium phlei activities and five strains had activities against methicillin-resistant Staphylococcus aureus. 10 L-scale fermentation of strains Salinispora sp. NHF45, Nocardiopsis sp. NHF48, and Streptomyces sp. NHF86 were carried out for novel and bioactive compounds discovery. Finally, we obtained a novel α-pyrone compound from marine Nocardiopsis sp. NHF48, an analogue of paulomenol from marine Streptomyces sp. NHF86 and a new source of rifamycin B, produced by Salinispora sp. NHF45. The present study concluded that marine actinomycetes, which we isolated from South China Sea sediments, will be a suitable source for the development of novel and bioactive compounds.

Evaluation of novel thermo-resistant Micractinium and Scenedesmus sp. for efficient biomass and lipid production under different temperature and nutrient regimes.

PubMed

Sonmez, Cagla; Elcin, Evrim; Akın, Dilan; Oktem, Huseyin Avni; Yucel, Meral

2016-07-01

Despite the vast interest in microalgae as feedstock for biodiesel production, relatively few studies examined their response to diurnal temperature fluctuation. Here, we describe biomass and lipid productivities and fatty acid profiles of thermo-resistant Micractinium sp. and Scenedesmus sp. grown in batch cultures in a laboratory set-up that mimics a typically warm summer day in Central Anatolia with a 16-h light temperature of 30°C and 8-h dark temperature of 16°C (30°C (day)/16°C (night)). Both strains can survive a temperature range of 10-50°C. We found the lipid productivities of Micractinium sp. and Scenedesmus sp. as 30/21mgL(-1)d(-1) and 6/7mgL(-1)d(-1), respectively during the 30°C (day)/16°C (night) cycle. Saturated fatty acid content increased with increasing temperature. Additionally, we cultured Micractinium sp. under Nitrogen (N) and Phosphorus (P) limiting conditions. Highest lipid productivity of 85.4±2mgL(-1)d(-1) was obtained under P-depletion during exponential growth phase. Oleic acid amount also increased eight fold during P-deplete. Copyright © 2016 Elsevier Ltd. All rights reserved.

Infections caused by pathogenic free-living amebas (Balamuthia mandrillaris and Acanthamoeba sp.) in horses.

PubMed

Kinde, Hailu; Read, Deryck H; Daft, Barbara M; Manzer, Michael; Nordhausen, Robert W; Kelly, Daryl J; Fuerst, Paul A; Booton, Gregory; Visvesvara, Govinda S

2007-05-01

This article describes amebic infections in 4 horses: granulomatous amebic encephalitis caused by Balamuthia mandrillaris and Acanthamoeba culbertsoni and systemic infections caused by Acanthamoeba sp. The former infection occurred in 1 of 4 horses spontaneously without any underlying conditions; the latter amebic infection was perhaps "opportunistic" considering the visceral involvement by this protozoan in association with Aspergillus sp. and/or Escherichia coli and Pseudomonas sp. The clinicopathologic findings and demonstration of the amebic organisms using immunohistochemical techniques, culture, polymerase chain reactions, and electron microscopy are presented.

Growth and enzymatic responses of phytopathogenic fungi to glucose in culture media and soil

PubMed Central

Costa, Beatriz de Oliveira; Nahas, Ely

2012-01-01

The effect of inoculation of Aspergillus flavus , Fusarium verticillioides , and Penicillium sp. in Dystrophic Red Latosol (DRL) and Eutroferric Red Latosol (ERL) soils with or without glucose on the total carbohydrate content and the dehydrogenase and amylase activities was studied. The fungal growth and spore production in culture medium with and without glucose were also evaluated. A completely randomized design with factorial arrangement was used. The addition of glucose in the culture medium increased the growth rate of A. flavus and Penicillium sp. but not of F. verticillioides . The number of spores increased 1.2 for F. verticillioides and 8.2 times for A. flavus in the medium with glucose, but was reduced 3.5 times for Penicillium sp. The total carbohydrates contents reduced significantly according to first and second degree equations. The consumption of total carbohydrates by A. flavus and Penicillium sp. was higher than the control or soil inoculated with F. verticillioides . The addition of glucose to soils benefited the use of carbohydrates, probably due to the stimulation of fungal growth. Dehydrogenase activity increased between 1.5 to 1.8 times ( p <0.05) in soils with glucose and inoculated with the fungi (except F. verticillioides ), in relation to soil without glucose. Amylase activity increased 1.3 to 1.5 times due to the addition of glucose in the soil. Increased amylase activity was observed in the DRL soil with glucose and inoculated with A. flavus and Penicillium sp. when compared to control. PMID:24031836

Elucidating MTBE degradation in a mixed consortium using a multidisciplinary approach.

PubMed

Bastida, Felipe; Rosell, Mònica; Franchini, Alessandro G; Seifert, Jana; Finsterbusch, Stefanie; Jehmlich, Nico; Jechalke, Sven; von Bergen, Martin; Richnow, Hans H

2010-08-01

The structure and function of a microbial community capable of biodegrading methyl-tert-butyl ether (MTBE) was characterized using compound-specific stable isotope analysis (CSIA), clone libraries and stable isotope probing of proteins (Protein-SIP). The enrichment culture (US3-M), which originated from a gasoline-impacted site in the United States, has been enriched on MTBE as the sole carbon source. The slope of isotopic enrichment factors (epsilon(C) of -2.29+/-0.03 per thousand; epsilon(H) of -58+/-6 per thousand) for carbon and hydrogen discrimination (Deltadelta(2)H/Deltadelta(13)C) was on average equal to Lambda=24+/-2, a value closely related to the reaction mechanism of MTBE degradation in Methylibium petroleiphilum PM1. 16S rRNA gene libraries revealed sequences belonging to M. petroleiphilum PM1, Hydrogenophaga sp., Thiothrix unzii, Rhodobacter sp., Nocardiodes sp. and different Sphingomonadaceae bacteria. Protein-SIP analysis of the culture grown on (13)C-MTBE as the only carbon source revealed that proteins related to members of the Comamonadaceae family, such as Delftia acidovorans, Acidovorax sp. or Comamonas sp., were not (13)C-enriched, whereas proteins related to M. petroleiphilum PM1 showed an average incorporation of 94.5 atom%(13)C. These results indicate a key role for this species in the degradation of MTBE within the US3-M consortia. The combination of CSIA, molecular biology and Protein-SIP facilitated the analysis of an MTBE-degrading mixed culture from a functional and phylogenetic point of view.

Application of Low cost Spirulina growth medium using Deep sea water

NASA Astrophysics Data System (ADS)

Lim, Dae-hack; Kim, Bong-ju; Lee, Sung-jae; Choi, Nag-chul; Park, Cheon-young

2017-04-01

Deep-sea water has a relatively constant temperature, abundant nutrients such as calcium, magnesium, nitrates, and phosphates, etc., and stable water quality, even though there might be some variations of their compositions according to collection places. Thus, deep-sea water would be a good substrate for algal growth and biomass production since it contains various nutrients, including a fluorescent red pigment, and β-carotene, etc. The aim of this study was to investigate the economics of a culture condition through comparative analysis to Spirulina platensis growth characteristic under various medium conditions for cost-effective production of Spirulina sp.. Growth experiments were performed with S. platensis under various culture medium conditions (deep sea water + SP medium). Growth tests for culture medium demonstrated that the deep sea water to SP medium ratio of 50:50(W/W) was effective in S. platensis with the maximum biomass (1.35g/L) and minimum medium making cost per production mass (133.28 KRW/g). Parameter estimation of bio-kinetics (maximum growth rate and yield) for low cost medium results showed that the maximum growth rate and yield of N, P, K were obtained under deep sea water to SP medium ratio of 50:50(W/W) of 0.057 1/day and 0.151, 0.076, 0.123, respectively. Acknowledgment : "This research was a part of the project titled 'Development of microalgae culture technique for cosmetic materials based on ocean deep sea water(20160297)', funded by the Ministry of Oceans and Fisheries, Korea."

[The comparison on growth rate and photopigments of filaments of Spirulina platensis strain Z with different morphology].

PubMed

Wang, Z; Cui, H; Zhu, J; Jia, X; Qian, K

1998-08-01

The line-shaped filaments Sp-Z(L) were isolated and cultured from Spirulina platensis Sp-Z. The growth rate of Sp-Z(L) was only 64% as much as that of Sp-Z when the light intensity was 4000 Lux. The contents (x 10(-3) g/g dry weight) of chlorophylls, carotenoids and phycobilins of Sp-Z(L) and Sp-Z were 20.6, 0.343, 5.00 and 24.1 0.297, 4.46, respectively. Moreover, as to the absorption spectra of the three photopigments of Sp-Z(L), red shifts were observed. Therefore, after the spiral Sp-Z breeded or changed into Sp-Z(L), The contents of carotenoids and phycobilins raised 23% and 12%, respectively, but the contents of chlorophylls dropped 14.5%, and the growth rate dropped 36% too. The results probably showed that the decrease of chlorophylls was one of the main reasons that caused the remarkable decrease of the growth rate of Sp-Z(L).

Optimization of lipids' ultrasonic extraction and production from Chlorella sp. using response-surface methodology.

PubMed

Hadrich, Bilel; Akremi, Ismahen; Dammak, Mouna; Barkallah, Mohamed; Fendri, Imen; Abdelkafi, Slim

2018-04-17

Three steps are very important in order to produce microalgal lipids: (1) controlling microalgae cultivation via experimental and modeling investigations, (2) optimizing culture conditions to maximize lipids production and to determine the fatty acid profile the most appropriate for biodiesel synthesis, and (3) optimizing the extraction of the lipids accumulated in the microalgal cells. Firstly, three kinetics models, namely logistic, logistic-with-lag and modified Gompertz, were tested to fit the experimental kinetics of the Chlorella sp. microalga culture established on standard conditions. Secondly, the response-surface methodology was used for two optimizations in this study. The first optimization was established for lipids production from Chlorella sp. culture under different culture conditions. In fact, different levels of nitrate concentrations, salinities and light intensities were applied to the culture medium in order to study their influences on lipids production and determine their fatty acid profile. The second optimization was concerned with the lipids extraction factors: ultrasonic's time and temperature, and chloroform-methanol solvent ratio. All models (logistic, logistic-with-lag and modified Gompertz) applied for the experimental kinetics of Chlorella sp. show a very interesting fitting quality. The logistic model was chosen to describe the Chlorella sp. kinetics, since it yielded the most important statistical criteria: coefficient of determination of the order of 94.36%; adjusted coefficient of determination equal to 93.79% and root mean square error reaching 3.685 cells · ml - 1 . Nitrate concentration and the two interactions involving the light intensity (Nitrate concentration × light intensity, and salinities × light intensity) showed a very significant influence on lipids production in the first optimization (p < 0.05). Yet, only the quadratic term of chloroform-methanol solvent ratio showed a significant influence on lipids extraction relative to the second step of optimization (p < 0.05). The two most abundant fatty acid methyl esters (≈72%) derived from the Chlorella sp. microalga cultured in the determined optimal conditions are: palmitic acid (C16:0) and oleic acid (C18:1) with the corresponding yields of 51.69% and 20.55% of total fatty acids, respectively. Only the nitrate deficiency and the high intensity of light can influence the microalgal lipids production. The corresponding fatty acid methyl esters composition is very suitable for biodiesel production. Lipids extraction is efficient only over long periods of time when using a solvent with a 2/1 chloroform/methanol ratio.

Comparison of background levels of culturable fungal spore concentrations in indoor and outdoor air in southeastern Austria

NASA Astrophysics Data System (ADS)

Haas, D.; Habib, J.; Luxner, J.; Galler, H.; Zarfel, G.; Schlacher, R.; Friedl, H.; Reinthaler, F. F.

2014-12-01

Background concentrations of airborne fungi are indispensable criteria for an assessment of fungal concentrations indoors and in the ambient air. The goal of this study was to define the natural background values of culturable fungal spore concentrations as reference values for the assessment of moldy buildings. The concentrations of culturable fungi were determined outdoors as well as indoors in 185 dwellings without visible mold, obvious moisture problems or musty odor. Samples were collected using the MAS-100® microbiological air sampler. The study shows a characteristic seasonal influence on the background levels of Cladosporium, Penicillium and Aspergillus. Cladosporium sp. had a strong outdoor presence, whereas Aspergillus sp. and Penicillium sp. were typical indoor fungi. For the region of Styria, the median outdoor concentrations are between 100 and 940 cfu/m³ for culturable xerophilic fungi in the course of the year. Indoors, median background levels are between 180 and 420 cfu/m³ for xerophilic fungi. The I/O ratios of the airborne fungal spore concentrations were between 0.2 and 2.0. For the assessment of indoor and outdoor air samples the dominant genera Cladosporium, Penicillium and Aspergillus should receive special consideration.

Influence of culture conditions and medium composition on the production of antibacterial compounds by marine Serratia sp. WPRA3.

PubMed

Jafarzade, Mahtab; Yahya, Nur Ain; Shayesteh, Fatemeh; Usup, Gires; Ahmad, Asmat

2013-06-01

This study was undertaken to investigate the influence of culture conditions and medium components on production of antibacterial compounds by Serratia sp. WPRA3 (JX020764) which was isolated from marine water of Port Dickson, Malaysia. Biochemical, morphological, and molecular characteristics suggested that the isolate is a new candidate of the Serratia sp. The isolate showed strong antimicrobial activity against fungi, Gram-negative and Gram-positive bacteria. This bacterium exhibited optimum antibacterial compounds production at 28°C, pH 7 and 200 rev/min aeration during 72 h of incubation period. Highest antibacterial activity was obtained when sodium chloride (2%), yeast extract (0.5%), and glucose concentration (0.75%) were used as salt, nitrogen, and carbon sources respectively. Different active fractions were obtained by Thin-Layer Chromatography (TLC) and Flash Column Chromatography (FCC) from ethyl acetate crude extracts namely OCE and RCE in different culture conditions, OCE (pH 5, 200 rev/min) and RCE (pH 7/without aeration). In conclusion, the results suggested different culture conditions have a significant impact on the types of secondary metabolites produced by the bacterium.

Simultaneous microalgal biomass production and CO2 fixation by cultivating Chlorella sp. GD with aquaculture wastewater and boiler flue gas.

PubMed

Kuo, Chiu-Mei; Jian, Jhong-Fu; Lin, Tsung-Hsien; Chang, Yu-Bin; Wan, Xin-Hua; Lai, Jinn-Tsyy; Chang, Jo-Shu; Lin, Chih-Sheng

2016-12-01

A microalgal strain, Chlorella sp. GD, cultivated in aquaculture wastewater (AW) aerated with boiler flue gas, was investigated. When AW from a grouper fish farm was supplemented with additional nutrients, the microalgal biomass productivity after 7days of culture was 0.794gL -1 d -1 . CO 2 fixation efficiencies of the microalgal strains aerated with 0.05, 0.1, 0.2, and 0.3vvm of boiler flue gas (containing approximately 8% CO 2 ) were 53, 51, 38, and 30%, respectively. When the microalgal strain was cultured with boiler flue gas in nutrient-added AW, biomass productivity increased to 0.892gL -1 d -1 . In semi-continuous cultures, average biomass productivities of the microalgal strain in 2-day, 3-day, and 4-day replacement cultures were 1.296, 0.985, and 0.944gL -1 d -1 , respectively. These results demonstrate the potential of using Chlorella sp. GD cultivations in AW aerated with boiler flue gas for reusing water resources, reducing CO 2 emission, and producing microalgal biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan salt lake on Qinghai-Tibet Plateau].

PubMed

Shen, Shuo

2017-04-04

I studied the community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan Salt Lake. I isolated and cultured the moderate halophilic bacteria on different selective media. After the 16S rRNA gene sequences was amplified and measured, I constructed the phylogenic tree, analyzed the community structure and calculated the diversity indexes according to the 16S rRNA gene information. A total of 421 moderate halophilic bacteria were isolated from water and mud samples in Qrhan Salt Lake. The 16S rRNA gene information showed that 4 potential novel species belonged to the family Bacillaceae. Eighty-three model strains belonged to 3 phylurms 6 families 16 genus. Among them, Bacillus sp., Oceanobacillus sp. and Halomonas sp. were dominant species. Diversity analysis showed that the diversity of strains isolated from water sample was higher than that from mud sample, but the dominance degree of strains isolated from mud sample was higher than that from water sample. The genetic diversity of moderate halophilic bacteria isolated from Qrhan Salt Lake was abundant. Also, there were dominant and novel species of culturable moderate halophilic bacteria in this lake.

Structural Investigation of Biological and Semiconductor Nanostructures with Nonlinear Multicontrast Microscopy

NASA Astrophysics Data System (ADS)

Cisek, Richard

Physical and functional properties of advanced nano-composite materials and biological structures are determined by self-organized atoms and molecules into nanostructures and in turn by microscopic organization of the nanostructures into assemblies of higher structural complexity. Therefore, microscopes are indispensable tools for structural investigations at various levels of organization. In this work, novel nonlinear optical microscopy methods were developed to non-invasively study structural organization at the nanoscopic and microscopic levels. Atomic organization of semiconductor nanowires, molecular organization of amylose biocrystallites in starch granules, and microscopic organization of several photosynthetic organisms was elucidated. The structure of ZnSe nanowires, key components in many modern nanodevices, was investigated using polarization harmonic generation microscopy. Based on nonlinear optical properties of the different crystal lattices, zinc blende and wurtzite nanowires were differentiated, and the three-dimensional orientation of the zinc blende nanowires could be found. The structure of starch granules, a model biocrystal, important in food as well as health sciences, was also investigated using polarization harmonic microscopy. The study was combined with ab initio calculations using the crystal structures of amylose A and B, revealing that second harmonic signals originate from the hydroxide and hydrogen bonds in the starch granules. Visualization of several photosynthetic organisms including the green algae, Chlamydomonas reinhardtii, two species of cyanobacteria, Leptolyngbya sp. and Anabaena sp., aggregates of light-harvesting pigment-protein complexes as well as chloroplasts from green plants were also explored, revealing that future nonlinear microscopy applications could include structural studies of cell walls, the Chlamydomonas eyespot, and photosynthetic membranes. In this study, several nonlinear optical microscopy modalities were developed for quantitative structural investigations of nano and micro-sized architectures. Non-invasive extraction of crystallographic information in microscopic samples will have a number of potential benefits, for example, in clinical applications, allowing observations of disease states inside tissues without the need for biopsy. Industrial nanotechnology will benefit from fast determination of nanostructures with nonlinear microscopy that will improve quality of nanodevices.

Quality improvement on half-fin anchovy (Setipinna taty) fish sauce by Psychrobacter sp. SP-1 fermentation.

PubMed

Zheng, Bin; Liu, Yu; He, Xiaoxia; Hu, Shiwei; Li, Shijie; Chen, Meiling; Jiang, Wei

2017-10-01

A method of improving fish sauce quality during fermentation was investigated. Psychrobacter sp. SP-1, a halophilic protease-producing bacterium, was isolated from fish sauce with flavor-enhancing properties and non-biogenic amine-producing activity. The performance of Psychrobacter sp. SP-1 in Setipinna taty fish sauce fermentation was investigated further. The inoculation of Psychrobacter sp. SP-1 did not significantly affect pH or NaCl concentration changes (P > 0.05), although it significantly increased total moderately halophilic microbial count, protease activity, total soluble nitrogen content and amino acid nitrogen content, and also promoted the umami taste and meaty aroma (P < 0.05). Furthermore, the inoculation of Psychrobacter sp. SP-1 significantly decreased total volatile basic nitrogen content and biogenic amines content (P < 0.05), which were regarded as harmful compounds in foods. The results of the present study demonstrate that Psychrobacter sp. SP-1 can be used as a potential starter culture for improving fish sauce quality by fermentation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Optimization of cellulase production by Penicillium sp.

PubMed

Prasanna, H N; Ramanjaneyulu, G; Rajasekhar Reddy, B

2016-12-01

The production of cellulolytic enzymes (β-exoglucanase, β-endoglucanase and β-glucosidase) by Penicillium sp. on three different media in liquid shake culture conditions was compared. The organism exhibited relatively highest activity of endoglucanase among three enzymes measured at 7-day interval during the course of its growth on Czapek-Dox medium supplemented with 0.5 % (w/v) cellulose. Cellulose at 0.5 %, lactose at 0.5 %, sawdust at 0.5 %, yeast extract at 0.2 % as a nitrogen source, pH 5.0 and 30 °C temperature were found to be optimal for growth and cellulase production by Penicillium sp. Yields of Fpase, CMCase and β-glucosidase, attained on optimized medium with Penicillium sp. were 8.7, 25 and 9.52 U/ml, respectively with increment of 9.2, 5.9 and 43.8-folds over titers of the respective enzyme on unoptimised medium. Cellulase of the fungal culture with the ratio of β-glucosidase to Fpase greater than one will hold potential for biotechnological applications.

Endothelialization of TiO2 Nanorods Coated with Ultrathin Amorphous Carbon Films

NASA Astrophysics Data System (ADS)

Chen, Hongpeng; Tang, Nan; Chen, Min; Chen, Dihu

2016-03-01

Carbon plasma nanocoatings with controlled fraction of sp3-C bonding were deposited on TiO2 nanorod arrays (TNAs) by DC magnetic-filtered cathodic vacuum arc deposition (FCVAD). The cytocompatibility of TNA/carbon nanocomposites was systematically investigated. Human umbilical vein endothelial cells (HUVECs) were cultured on the nanocomposites for 4, 24, and 72 h in vitro. It was found that plasma-treated TNAs exhibited excellent cell viability as compared to the untreated. Importantly, our results show that cellular responses positively correlate with the sp3-C content. The cells cultured on high sp3-C-contented substrates exhibit better attachment, shape configuration, and proliferation. These findings indicate that the nanocomposites with high sp3-C content possessed superior cytocompatibility. Notably, the nanocomposites drastically reduced platelet adhesion and activation in our previous studies. Taken together, these findings suggest the TNA/carbon scaffold may serve as a guide for the design of multi-functionality devices that promotes endothelialization and improves hemocompatibility.

Application of Fungicides and Microalgal Phenolic Extracts for the Direct Control of Fumonisin Contamination in Maize.

PubMed

Scaglioni, Priscila Tessmer; Blandino, Massimo; Scarpino, Valentina; Giordano, Debora; Testa, Giulio; Badiale-Furlong, Eliana

2018-05-16

Fungicides and, for the first time, microalgal phenolic extracts (MPE) from Spirulina sp. and Nannochloropsis sp. were applied on maize culture media under field conditions to evaluate their ability to minimize Fusarium species development and fumonisin production. An in vitro assay against F. verticillioides was carried out using maize grains as the culture medium. An open-field experiment was carried out in Northwest Italy under natural infection conditions. The compared treatments were factorial combinations of two insecticide treatments (an untreated control and pyrethroid, used against European Corn Borer), four antifungal treatments (an untreated control, MPE from Spirulina sp., MPE from Nannochloropsis sp., and a synthetic fungicide), and two timings of the application of the antifungal compounds (at maize flowering and at the milk stage). The MPE compounds were capable of inhibiting fumonisin production in vitro more efficiently than tebuconazole. Insecticide application reduced the infection by Fusarium species and subsequent fumonisin contamination. However, fumonisins in maize fields were not significantly controlled by either fungicide or MPE application.

Phosphate Solubilization Potential and Phosphatase Activity Of Rhizospheric Trichoderma Spp.

PubMed Central

Anil, Kapri; Lakshmi, Tewari

2010-01-01

Trichoderma sp., a well known biological control agent against several phytopathogens, was tested for its phosphate (P) solubilizing potential. Fourteen strains of Trichoderma sp. were isolated from the forest tree rhizospheres of pinus, deodar, bamboo, guava and oak on Trichoderma selective medium. The isolates were tested for their in-vitro P-solubilizing potential using National Botanical Research Institute Phosphate (NBRIP) broth containing tricalcium phosphate (TCP) as the sole P source, and compared with a standard culture of T. harzianum. All the cultures were found to solubilize TCP but with varying potential. The isolate DRT-1 showed maximum amount of soluble phosphate (404.07 εg.ml-1), followed by the standard culture of T. harzianum (386.42 εg.ml-1) after 96 h of incubation at 30±10C. Extra-cellular acid and alkaline phosphatases of the fungus were induced only in the presence of insoluble phosphorus source (TCP). High extra-cellular alkaline phosphatase activity was recorded for the isolate DRT-1 (14.50 U.ml-1) followed by the standard culture (13.41 U.ml-1) at 72h. The cultures showed much lesser acid phosphatase activities. Under glasshouse conditions, Trichoderma sp. inoculation increased chickpea (Cicer arietinum) growth parameters including shoot length, root length, fresh and dry weight of shoot as well as roots, in P-deficient soil containing only bound phosphate (TCP). Shoot weight was increased by 23% and 33% by inoculation with the isolate DRT-1 in the soil amended with 100 and 200 mg TCP kg-1 soil, respectively, after 60 d of sowing. The study explores high P-solubilizing potential of Trichoderma sp., which can be exploited for the solubilization of fixed phosphates present in the soil, thereby enhancing soil fertility and plant growth. PMID:24031556

Symbiosis between microorganisms from kombucha and kefir: Potential significance to the enhancement of kombucha function.

PubMed

Yang, Zhiwei; Zhou, Feng; Ji, Baoping; Li, Bo; Luo, Yangchao; Yang, Li; Li, Tao

2010-01-01

Gluconacetobacter sp. A4 (G. sp. A4), which had strong ability to produce d-saccharic acid 1, 4 lactone (DSL), was the key functional bacteria isolated from the kombucha preserved. This paper investigated the interaction between G. sp. A4 and ten different strains of lactic acid bacteria (LAB) obtained from kefir. The result suggested that the LAB promoted DSL production of G. sp. A4 to different extents, ranging from 4.86% to 86.70%. Symbiosis between G. sp. A4 and LAB was studied. LAB's metabolites, xylitol, and acetic acid, were utilized by G. sp. A4, and it promoted the growth of G. sp. A4 and yield of DSL. Therefore, in developing starter cultures for kombucha fermentation process, a mixed flora of LAB and G. sp. A4 would be the optimal combination.

Outdoor cultivation of lutein-rich cells of Muriellopsis sp. in open ponds.

PubMed

Blanco, Antonio M; Moreno, José; Del Campo, José A; Rivas, Joaquín; Guerrero, Miguel G

2007-01-01

The growth performance of the chlorophycean microalga Muriellopsis sp. outdoors in open tanks agitated with a paddlewheel and its ability to accumulate carotenoids have been evaluated throughout the year. The cells grown in the open system had free lutein as the main carotenoid, with violaxanthin, beta-carotene, and neoxanthin also present. Lutein content of the dry biomass ranged from 0.4 to 0.6%, depending on the growth and environmental conditions. In addition, the biomass of Muriellopsis sp. had a high content in both protein and lipids with about half of the fatty acids being of the polyunsaturated type, with alpha-linolenic acid accounting for almost 30% of the total fatty acids. The effect of determinant parameters on the performance of the cultures in open tanks was evaluated. Operating conditions that allow the maintenance of productive cultures were established under semicontinuous regime for 9 months throughout the year. Biomass and lutein yields in the open system were not far from those in closed tubular photobioreactors, and reached productivity values of 20 g dry biomass, containing around 100 mg lutein m(-2) day(-1) in summer. The outdoor culture of Muriellopsis sp. in open ponds thus represents a real alternative to established systems for the production of lutein.

Synergistic growth studies of Entamoeba gingivalis using an Ecologen.

PubMed

Gannon, J T; Linke, H A

1992-11-01

A unique multiple diffusion growth chamber, an Ecologen, designed for the study of interactions among microorganisms, was introduced as a means of growing xenic cultures of Entamoeba gingivalis with Crithidia sp. or Yersinia enterocolitica. Entamoeba gingivalis was grown in the central diffusion reservoir of the Ecologen connected to separate growth chambers inoculated with the microorganisms to be evaluated. Growth of the accompanying bacteria in the E. gingivalis compartment was almost completely eliminated, except for sparse Pseudomonas sp. growth. The most vital E. gingivalis cultures were observed when either Crithidia sp. or Y. enterocolitica were added to the Ecologen 48 h prior to the E. gingivalis inoculum. The medium which provided the best growth of the oral protozoan in this system was the new improved E. gingivalis medium containing antibiotics.

[Cytotoxicity of the secondary metabolites of Marine Mangrove Fungus Paecilomyces sp. tree 1-7 on human hepatoma cell line HepG2].

PubMed

Cai, Xiao-Ling; Gao, Jun-Ping; Li, Qing; Wen, Lu; She, Zhi-Gang; Lin, Yong-Cheng

2008-06-01

To study the cytotoxicity of the secondary metabolites of Marine Mangrove Fungus Paecilomyces sp. Tree 1-7 on human hepatoma cell line HepG2 cultured in vitro. Three groups were divided: compounds group, 5-Fu group and control group. The cytotoxicity was measured by MTT method when HepG2 cells were treated by different concentration of the secondary metabolites of Paecilomyces sp. Tree 1-7. Secalonic acid A, tenellic acid A and alternin inhibited the growth of human hepatoma cell line HepG2, the IC50 separately were 2.0, 62.1 and 7.0 microg/ml. Secalonic acid A and alternin have strong cytotoxicity on HepG2 cultured in vitro.

Substance P reduces TNF-α-induced apoptosis in human tenocytes through NK-1 receptor stimulation.

PubMed

Backman, Ludvig J; Eriksson, Daniella E; Danielson, Patrik

2014-10-01

It has been hypothesised that an upregulation of the neuropeptide substance P (SP) and its preferred receptor, the neurokinin-1 receptor (NK-1 R), is a causative factor in inducing tenocyte hypercellularity, a characteristic of tendinosis, through both proliferative and antiapoptotic stimuli. We have demonstrated earlier that SP stimulates proliferation of human tenocytes in culture. The aim of this study was to investigate whether SP can mediate an antiapoptotic effect in tumour necrosis factor-α (TNF-α)-induced apoptosis of human tenocytes in vitro. A majority (approximately 75%) of tenocytes in culture were immunopositive for TNF Receptor-1 and TNF Receptor-2. Exposure of the cells to TNF-α significantly decreased cell viability, as shown with crystal violet staining. TNF-α furthermore significantly increased the amount of caspase-10 and caspase-3 mRNA, as well as both BID and cleaved-poly ADP ribosome polymerase (c-PARP) protein. Incubation of SP together with TNF-α resulted in a decreased amount of BID and c-PARP, and in a reduced lactate dehydrogenase release, as compared to incubation with TNF-α alone. The SP effect was blocked with a NK-1 R inhibitor. This study shows that SP, through stimulation of the NK-1 R, has the ability to reduce TNF-α-induced apoptosis of human tenocytes. Considering that SP has previously been shown to stimulate tenocyte proliferation, the study confirms SP as a potent regulator of cell-turnover in tendon tissue, capable of stimulating hypercellularity through different mechanisms. This gives further support for the theory that the upregulated amount of SP seen in tendinosis could contribute to hypercellularity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Translation and validation of a Spanish version of the xerostomia inventory.

PubMed

Serrano, Carlos; Fariña, María P; Pérez, Cristhian; Fernández, Marcos; Forman, Katherine; Carrasco, Mauricio

2016-12-01

The aim of this study was to validate a Spanish cross-cultural adaptation of the xerostomia inventory (XI). The original English version of XI was translated into Spanish, cross-culturally adapted and field tested. The Spanish version of XI (XI-Sp) was tested with a sample of 41 patients with xerostomia. The reliability of the XI-Sp was determined through internal consistency and test-retest methods. The construct validity of XI-Sp was determined by means of correlation between XI-Sp scores and salivary flow measurements. Overall XI-Sp scores were 40.8 (SD = 10) for the first application and 40.2 (SD = 9.5) for the second. Cronbach's alpha value for the XI-Sp was 0.89 and 0.87, respectively, while interitem correlation averages were r = 0.44 and r = 0.39 for each application. Interitem correlation and corrected total was r c ≥0.30. The test-retest intraclass correlation coefficient value for the XI-Sp score was 0.59 and 0.91. Convergent validity for construct validity correlation with salivary flow showed a medium effect size (r 2  = 0.10) for the first application but did not make a statistically significant prediction for the second (r 2  = 0.7). This study provides evidence concerning the reliability of the XI-Sp, showing that it may be a useful tool for Spanish-speaking xerostomia patients for both clinical and epidemiologic research. © 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Characterization of a novel Pseudomonas sp. that mineralizes high concentrations of pentachlorophenol.

PubMed Central

Radehaus, P M; Schmidt, S K

1992-01-01

A pentachlorophenol (PCP)-mineralizing bacterium was isolated from polluted soil and identified as Pseudomonas sp. strain RA2. In batch cultures, Pseudomonas sp. strain RA2 used PCP as its sole source of carbon and energy and was capable of completely degrading this compound as indicated by radiotracer studies, stoichiometric release of chloride, and biomass formation. Pseudomonas sp. strain RA2 was able to mineralize a higher concentration of PCP (160 mg liter-1) than any previously reported PCP-degrading pseudomonad. At a PCP concentration of 200 mg liter-1, cell growth was completely inhibited and PCP was not degraded, although an active population of Pseudomonas sp. RA2 was still present in these cultures after 2 weeks. The inhibitory effect of PCP was partially attributable to its effect on the growth rate of Pseudomonas sp. strain RA2. The highest specific growth rate (mu = 0.09 h-1) was reached at a PCP concentration of 40 mg liter-1 but decreased at higher or lower PCP concentrations, with the lowest mu (0.05 h-1) occurring at 150 mg liter-1. Despite this reduction in growth rate, total biomass production was proportional to PCP concentration at all PCP concentrations degraded by Pseudomonas sp. RA2. In contrast, final cell density was reduced to below expected values at PCP concentrations greater than 100 mg liter-1. These results indicate that, in addition to its effect as an uncoupler of oxidative phosphorylation, PCP may also inhibit cell division in Pseudomonas sp. strain RA2.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1444401

Possible linkage of SP6 transcriptional activity with amelogenesis by protein stabilization.

PubMed

Utami, Trianna W; Miyoshi, Keiko; Hagita, Hiroko; Yanuaryska, Ryna Dwi; Horiguchi, Taigo; Noma, Takafumi

2011-01-01

Ameloblasts produce enamel matrix proteins such as amelogenin, ameloblastin, and amelotin during tooth development. The molecular mechanisms of ameloblast differentiation (amelogenesis) are currently not well understood. SP6 is a transcription factor of the Sp/KLF family that was recently found to regulate cell proliferation in a cell-type-specific manner. Sp6-deficient mice demonstrate characteristic tooth anomalies such as delayed eruption of the incisors and supernumerary teeth with disorganized amelogenesis. However, it remains unclear how Sp6 controls amelogenesis. In this study, we used SP6 high producer cells to identify SP6 target genes. Based on the observations that long-term culture of SP6 high producer cells reduced SP6 protein expression but not Sp6 mRNA expression, we found that SP6 is short lived and specifically degraded through a proteasome pathway. We established an in vitro inducible SP6 expression system coupled with siRNA knockdown and found a possible linkage between SP6 and amelogenesis through the regulation of amelotin and Rock1 gene expression by microarray analysis. Our findings suggest that the regulation of SP6 protein stability is one of the crucial steps in amelogenesis.

Possible Linkage of SP6 Transcriptional Activity with Amelogenesis by Protein Stabilization

PubMed Central

Utami, Trianna W.; Miyoshi, Keiko; Hagita, Hiroko; Yanuaryska, Ryna Dwi; Horiguchi, Taigo; Noma, Takafumi

2011-01-01

Ameloblasts produce enamel matrix proteins such as amelogenin, ameloblastin, and amelotin during tooth development. The molecular mechanisms of ameloblast differentiation (amelogenesis) are currently not well understood. SP6 is a transcription factor of the Sp/KLF family that was recently found to regulate cell proliferation in a cell-type-specific manner. Sp6-deficient mice demonstrate characteristic tooth anomalies such as delayed eruption of the incisors and supernumerary teeth with disorganized amelogenesis. However, it remains unclear how Sp6 controls amelogenesis. In this study, we used SP6 high producer cells to identify SP6 target genes. Based on the observations that long-term culture of SP6 high producer cells reduced SP6 protein expression but not Sp6 mRNA expression, we found that SP6 is short lived and specifically degraded through a proteasome pathway. We established an in vitro inducible SP6 expression system coupled with siRNA knockdown and found a possible linkage between SP6 and amelogenesis through the regulation of amelotin and Rock1 gene expression by microarray analysis. Our findings suggest that the regulation of SP6 protein stability is one of the crucial steps in amelogenesis. PMID:22046099

The oxygen evolving enhancer protein 1 (OEE) of photosystem II in green algae exhibits thioredoxin activity.

PubMed

Heide, Heinrich; Kalisz, Henryk M; Follmann, Hartmut

2004-02-01

A thioredoxin-like chloroplast protein of the fructosebisphosphatase-stimulating f-type, but with an unusually high molecular mass of 28 kDa has previously been identified and purified to homogeneity in a fractionation scheme for resolution of the acid- and heat-stable, regular-size (12kDa) thioredoxins of the unicellular green algae, Scenedesmus obliquus. An apparently analogous protein of 26 kDa was described in a cyanobacterium, Anabaena sp., but no such large thioredoxin species f exists in the thioredoxin profiles of higher plants. The structure of the 28 kDa protein, which had been envisaged to represent a precursor, or fusion product of the two more specialized, common chloroplast thioredoxins f and m has now been determined by amino acid sequencing. Although it exhibits virtually all the properties and enzyme-modulating activities of a thioredoxin proper this algal protein, surprisingly, does not belong to the thioredoxin family of small redox proteins but is identical with OEE (oxygen evolving enhancer) protein 1, an auxiliary component of the photosystem II manganese cluster. Extracts of Chlorella vulgaris and Chlamydomonas reinhardtii also contain heat-stable protein fractions of 23-26 kDa capable of specifically stimulating chloroplast fructosebisphosphatase in vitro. In contrast, OEE protein 1 from spinach is not able to modulate FbPase or NADP malate dehydrogenase from spinach chloroplasts. A dual function of the OEE protein in algal photosynthesis is envisaged.

Stratification by cyanobacteria in lakes: a dynamic buoyancy model indicates size limitations met by Planktothrix rubescens filaments.

PubMed

Walsby, Anthony E

2005-11-01

The ability of the Planktothrix rubescens to stratify in Lake Zürich is related to the size and shape of the cyanobacterial filaments. Detailed measurements made in the lake are used in a dynamic computer model of buoyancy regulation to investigate the vertical movements of filaments tracking the depth at which the irradiance would support neutral buoyancy. The movement of the filament lags behind the constantly changing target depth owing to (a) the time taken for the filament to respond to the irradiance by changing its density and (b) the time it takes to move by sinking down or floating up through the water column. The model simulates the stratification depth over a 5-month period of the summer from the continuous measurements of irradiance and weekly measurements of light attenuation and temperature, without any further adjustment over the period. Models using filaments of the size observed in Lake Zürich explain several details of the observed depth changes: smaller planktonic cyanobacteria (e.g. Limnothrix sp.) are unable to migrate fast enough and larger ones (e.g. Anabaena spp.) will overshoot and become entrained in the epilimnion. The model can be used to simulate recruitment of Planktothrix filaments from different depths after vernal stratification. Recruitment of filaments from depths down to 45 m will contribute to the metalimnetic population increase in early July.

Kinetics of chromate reduction during naphthalene degradation in a mixed culture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, H.; Sewell, G.W.; Pritchard, P.H.

A mixed culture of Bacillus sp. K1 and Sphingomonas paucimobilis EPA 505 was exposed to chromate and naphthalene. Batch experiments showed that chromate was reduced and naphthalene was degraded by the mixed culture. Chromate reduction occurred initially at a high rate followed by a decrease in rate until chromate reduction ceased. Chromate reduction decreased in the mixed culture when a lower ratio of S. paucimobilis EPA 505 to Bacillus sp. K1 was utilized. A kinetic model incorporating a term for the cell density ratio is proposed to describe chromate reduction in the mixed culture under both chromate limited and electronmore » donor limited conditions. The validity of the model, and its parameter values, was verified by experimental data generated under a variety of initial population compositions and a broad range of chromate concentrations. The consistent result of experimental data with model predictions implies that the model is useful for evaluating the interactions and the use of mixed culture for chromate removal.« less

The Peptidoglycan-Binding Protein SjcF1 Influences Septal Junction Function and Channel Formation in the Filamentous Cyanobacterium Anabaena.

PubMed

Rudolf, Mareike; Tetik, Nalan; Ramos-León, Félix; Flinner, Nadine; Ngo, Giang; Stevanovic, Mara; Burnat, Mireia; Pernil, Rafael; Flores, Enrique; Schleiff, Enrico

2015-06-30

Filamentous, heterocyst-forming cyanobacteria exchange nutrients and regulators between cells for diazotrophic growth. Two alternative modes of exchange have been discussed involving transport either through the periplasm or through septal junctions linking adjacent cells. Septal junctions and channels in the septal peptidoglycan are likely filled with septal junction complexes. While possible proteinaceous factors involved in septal junction formation, SepJ (FraG), FraC, and FraD, have been identified, little is known about peptidoglycan channel formation and septal junction complex anchoring to the peptidoglycan. We describe a factor, SjcF1, involved in regulation of septal junction channel formation in the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. SjcF1 interacts with the peptidoglycan layer through two peptidoglycan-binding domains and is localized throughout the cell periphery but at higher levels in the intercellular septa. A strain with an insertion in sjcF1 was not affected in peptidoglycan synthesis but showed an altered morphology of the septal peptidoglycan channels, which were significantly wider in the mutant than in the wild type. The mutant was impaired in intercellular exchange of a fluorescent probe to a similar extent as a sepJ deletion mutant. SjcF1 additionally bears an SH3 domain for protein-protein interactions. SH3 binding domains were identified in SepJ and FraC, and evidence for interaction of SjcF1 with both SepJ and FraC was obtained. SjcF1 represents a novel protein involved in structuring the peptidoglycan layer, which links peptidoglycan channel formation to septal junction complex function in multicellular cyanobacteria. Nonetheless, based on its subcellular distribution, this might not be the only function of SjcF1. Cell-cell communication is central not only for eukaryotic but also for multicellular prokaryotic systems. Principles of intercellular communication are well established for eukaryotes, but the mechanisms and components involved in bacteria are just emerging. Filamentous heterocyst-forming cyanobacteria behave as multicellular organisms and represent an excellent model to study prokaryotic cell-cell communication. A path for intercellular metabolite exchange appears to involve transfer through molecular structures termed septal junctions. They are reminiscent of metazoan gap junctions that directly link adjacent cells. In cyanobacteria, such structures need to traverse the peptidoglycan layers in the intercellular septa of the filament. Here we describe a factor involved in the formation of channels across the septal peptidoglycan layers, thus contributing to the multicellular behavior of these organisms. Copyright © 2015 Rudolf et al.

Agrobacterium-mediated transformation of lipomyces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Ziyu; Magnuson, Jon K.; Deng, Shuang

This disclosure provides Agrobacterium-mediated transformation methods for the oil-producing (oleaginous) yeast Lipomyces sp., as well as yeast produced by the method. Such methods utilize Agrobacterium sp. cells that have a T-DNA binary plasmid, wherein the T-DNA binary plasmid comprises a first nucleic acid molecule encoding a first protein and a second nucleic acid molecule encoding a selective marker that permits growth of transformed Lipomyces sp. cells in selective culture media comprising an antibiotic.

Outdoor Growth Characterization of an Unknown Microalga Screened from Contaminated Chlorella Culture.

PubMed

Huo, Shuhao; Shang, Changhua; Wang, Zhongming; Zhou, Weizheng; Cui, Fengjie; Zhu, Feifei; Yuan, Zhenhong; Dong, Renjie

2017-01-01

Outdoor microalgae cultivation process is threatened by many issues, such as pest pollution and complex, changeable weather. Therefore, it is difficult to have identical growth rate for the microalgae cells and to keep their continuous growth. Outdoor cultivation requires the algae strains not only to have a strong ability to accumulate oil, but also to adapt to the complicated external environment. Using 18S rRNA technology, one wild strain Scenedesmus sp. FS was isolated and identified from the culture of Chlorella zofingiensis . Upon contamination by Scenedesmus sp., the species could quickly replace Chlorella zofingiensis G1 and occupy ecological niche in the outdoor column photobioreactors. The results indicated that Scenedesmus sp. FS showed high alkali resistance. It also showed that even under the condition of a low inoculum rate (OD 680 , 0.08), Scenedesmus sp. FS could still grow in the outdoor raceway pond under a high alkaline environment. Even under unoptimized conditions, the oil content of Scenedesmus sp. FS could reach more than 22% and C16-C18 content could reach up to 79.68%, showing that this species has the potential for the biodiesel production in the near future.

Outdoor Growth Characterization of an Unknown Microalga Screened from Contaminated Chlorella Culture

PubMed Central

Zhou, Weizheng; Zhu, Feifei

2017-01-01

Outdoor microalgae cultivation process is threatened by many issues, such as pest pollution and complex, changeable weather. Therefore, it is difficult to have identical growth rate for the microalgae cells and to keep their continuous growth. Outdoor cultivation requires the algae strains not only to have a strong ability to accumulate oil, but also to adapt to the complicated external environment. Using 18S rRNA technology, one wild strain Scenedesmus sp. FS was isolated and identified from the culture of Chlorella zofingiensis. Upon contamination by Scenedesmus sp., the species could quickly replace Chlorella zofingiensis G1 and occupy ecological niche in the outdoor column photobioreactors. The results indicated that Scenedesmus sp. FS showed high alkali resistance. It also showed that even under the condition of a low inoculum rate (OD680, 0.08), Scenedesmus sp. FS could still grow in the outdoor raceway pond under a high alkaline environment. Even under unoptimized conditions, the oil content of Scenedesmus sp. FS could reach more than 22% and C16–C18 content could reach up to 79.68%, showing that this species has the potential for the biodiesel production in the near future. PMID:28357405

Continuous Cultivation for Apparent Optimization of Defined Media for Cellulomonas sp. and Bacillus cereus

PubMed Central

Summers, R. J.; Boudreaux, D. P.; Srinivasan, V. R.

1979-01-01

Steady-state continuous culture was used to optimize lean chemically defined media for a Cellulomonas sp. and Bacillus cereus strain T. Both organisms were extremely sensitive to variations in trace-metal concentrations. However, medium optimization by this technique proved rapid, and multifactor screening was easily conducted by using a minimum of instrumentation. The optimized media supported critical dilution rates of 0.571 and 0.467 h−1 for Cellulomonas and Bacillus, respectively. These values approximated maximum growth rate values observed in batch culture. PMID:16345417

Bacillus swezeyi sp. nov. and Bacillus haynesii sp. nov., isolated from desert soil

USDA-ARS?s Scientific Manuscript database

Two isolates of Gram-positive, facultatively anaerobic, motile, rod-shaped, endospore-forming bacteria were identified during a survey of the diversity of Bacillus strains deposited in the Agriculture Research Service Culture Collection. These strains were originally isolated from soil in Evolution ...

CROSS-INDUCTION OF PYRENE AND PHENANTHRENE IN MYCOBACTERIUM SP. ISOLATED FROM POLYCYCLIC AROMATIC HYDROCARBON CONTAMINATED RIVER SEDIMENTS

EPA Science Inventory

A polycyclic aromatic hydrocarbon (PAH)-degrading culture enriched from contaminated river sediments and a Mycobacterium sp. isolated from the enrichment were tested to investigate the possible synergistic and antagonistic interactions affecting the degradation of pyrene in the p...

A novel endophytic Huperzine A-producing fungus, Shiraia sp. Slf14, isolated from Huperzia serrata.

PubMed

Zhu, D; Wang, J; Zeng, Q; Zhang, Z; Yan, R

2010-10-01

To characterize and identify a novel Huperzine A (HupA)-producing fungal strain Slf14 isolated from Huperzia serrata (Thunb. ex Murray) Trev. in China. The isolation, identification and characterization of a novel endophytic fungus producing HupA specifically and consistently from the leaves of H. serrata were investigated. The fungus was identified as Shiraia sp. Slf14 by molecular and morphological methods. The HupA produced by this endophytic fungus was shown to be identical to authentic HupA analysed by thin layer chromatographic, High-performance liquid chromatography (HPLC), LC-MS, (1) H NMR and acetylcholinesterase (AChE) inhibition activity in vitro. The amount of HupA produced by Shiraia sp. Slf14 was quantified to be 327.8 μg l(-1) by HPLC, which was far higher than that of the reported endophytic fungi, Acremonium sp., Blastomyces sp. and Botrytis sp. The production of HupA by endophyte Shiraia sp. Slf14 is an enigmatic observation. It would be interesting to further study the HupA production and regulation by the cultured endophyte in H. serrata and in axenic cultures. Although the current accumulation of HupA by the endophyte is not very high, it could provide a promising alterative approach for large-scale production of HupA. However, further strain improvement and the fermentation process optimization are required to result in the consistent and dependable production. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Epidemiology of Salmonella sp. in California cull dairy cattle: prevalence of fecal shedding and diagnostic accuracy of pooled enriched broth culture of fecal samples.

PubMed

Abu Aboud, Omran A; Adaska, John M; Williams, Deniece R; Rossitto, Paul V; Champagne, John D; Lehenbauer, Terry W; Atwill, Robert; Li, Xunde; Aly, Sharif S

2016-01-01

The primary objective of this cross-sectional study was to estimate the crude, seasonal and cull-reason stratified prevalence of Salmonella fecal shedding in cull dairy cattle on seven California dairies. A secondary objective was to estimate and compare the relative sensitivity (Se) and specificity (Sp) for pools of 5 and 10 enriched broth cultures of fecal samples for Salmonella sp. detection. Seven dairy farms located in the San Joaquin Valley of California were identified and enrolled in the study as a convenience sample. Cull cows were identified for fecal sampling once during each season between 2014 and 2015, specifically during spring, summer, fall, and winter, and 10 cows were randomly selected for fecal sampling at the day of their sale. In addition, study personnel completed a survey based on responses of the herd manager to questions related to the previous four month's herd management. Fecal samples were frozen until testing for Salmonella. After overnight enrichment in liquid broth, pools of enrichment broth (EBP) were created for 5 and 10 samples. All individual and pooled broths were cultured on selective media with putative Salmonella colonies confirmed by biochemical testing before being serogrouped and serotyped. A total of 249 cull cows were enrolled into the study and their fecal samples tested for Salmonella. The survey-weighted period prevalence of fecal shedding of all Salmonella sp. in the cull cow samples across all study herds and the entire study period was 3.42% (N = 249; SE 1.07). The within herd prevalence of Salmonella shed in feces did not differ over the four study seasons (P = 0.074). The Se of culture of EBP of five samples was 62.5% (SE = 17.12), which was not statistically different from the Se of culture of EBP of 10 (37.5%, SE = 17.12, P = 0.48). The Sp of culture of EBP of five samples was 95.24% (SE = 3.29) and for pools of 10 samples was 100.00% (SE = 0). There was no statistical difference between the culture relative specificities of EBP of 5 and 10 (P > 0.99). Our study showed a numerically higher prevalence of Salmonella shedding in the summer, although the results were not significant, most likely due to a lack of power from the small sample size. A higher prevalence in summer months may be related to heat stress. To detect Salmonella, investigators may expect a 62.5% sensitivity for culture of EBP of five, relative to individual fecal sample enrichment and culture. In contrast, culture of EBP of 10 samples resulted in a numerically lower Se. Culture of EBP of size 5 or 10 samples, given similar prevalence and limit of detection, can be expected to yield specificities of 95 and 100%, respectively.

Epidemiology of Salmonella sp. in California cull dairy cattle: prevalence of fecal shedding and diagnostic accuracy of pooled enriched broth culture of fecal samples

PubMed Central

Abu Aboud, Omran A.; Adaska, John M.; Williams, Deniece R.; Rossitto, Paul V.; Champagne, John D.; Lehenbauer, Terry W.; Atwill, Robert; Li, Xunde

2016-01-01

Background The primary objective of this cross-sectional study was to estimate the crude, seasonal and cull-reason stratified prevalence of Salmonella fecal shedding in cull dairy cattle on seven California dairies. A secondary objective was to estimate and compare the relative sensitivity (Se) and specificity (Sp) for pools of 5 and 10 enriched broth cultures of fecal samples for Salmonella sp. detection. Methods Seven dairy farms located in the San Joaquin Valley of California were identified and enrolled in the study as a convenience sample. Cull cows were identified for fecal sampling once during each season between 2014 and 2015, specifically during spring, summer, fall, and winter, and 10 cows were randomly selected for fecal sampling at the day of their sale. In addition, study personnel completed a survey based on responses of the herd manager to questions related to the previous four month’s herd management. Fecal samples were frozen until testing for Salmonella. After overnight enrichment in liquid broth, pools of enrichment broth (EBP) were created for 5 and 10 samples. All individual and pooled broths were cultured on selective media with putative Salmonella colonies confirmed by biochemical testing before being serogrouped and serotyped. Results A total of 249 cull cows were enrolled into the study and their fecal samples tested for Salmonella. The survey-weighted period prevalence of fecal shedding of all Salmonella sp. in the cull cow samples across all study herds and the entire study period was 3.42% (N = 249; SE 1.07). The within herd prevalence of Salmonella shed in feces did not differ over the four study seasons (P = 0.074). The Se of culture of EBP of five samples was 62.5% (SE = 17.12), which was not statistically different from the Se of culture of EBP of 10 (37.5%, SE = 17.12, P = 0.48). The Sp of culture of EBP of five samples was 95.24% (SE = 3.29) and for pools of 10 samples was 100.00% (SE = 0). There was no statistical difference between the culture relative specificities of EBP of 5 and 10 (P > 0.99). Discussion Our study showed a numerically higher prevalence of Salmonella shedding in the summer, although the results were not significant, most likely due to a lack of power from the small sample size. A higher prevalence in summer months may be related to heat stress. To detect Salmonella, investigators may expect a 62.5% sensitivity for culture of EBP of five, relative to individual fecal sample enrichment and culture. In contrast, culture of EBP of 10 samples resulted in a numerically lower Se. Culture of EBP of size 5 or 10 samples, given similar prevalence and limit of detection, can be expected to yield specificities of 95 and 100%, respectively. PMID:27635350

KINETICS OF CHROMATE REDUCTION DURING NAPHTHALENE DEGRADATION IN A MIXED CULTURE

EPA Science Inventory

A mixed culture of Bacillus sp. K1 and Sphingomonas paucimobilis EPA 505 was exposed to chromate and naphthalene. Batch experiments showed that chromate was reduced and naphthalene was degraded by the mixed culture. Chromate reduction occurred initially at a high rate followed by...

Parasitic amoebae found in water bodies of Ukraine.

PubMed

Patsyuk, Marina

2017-12-01

Two parasitic amoebian species are found in mollusks of the water bodies of Ukraine. Vahlkampfia sp. is found in hepatopankreas of Unio conus Spengler, 1793, and Acanthamoeba sp. is observed in mantle cavity of Viviparus viviparus Linnaeus, 1758. For these protist species, the mollusks are shown to be intermediate hosts where amoebae feed and reproduce. An experimental infection with Vahlkampfia sp. and Acanthamoeba sp. was not successful, no pathological changes in mollusks were observed. These amoebae are successfully cultured in fresh water and agar medium, hence we can safely consider them free-living. Copyright © 2017 Elsevier Inc. All rights reserved.

Reparation and Immunomodulating Properties of Bacillus sp. Metabolites from Permafrost.

PubMed

Kalenova, L F; Melnikov, V P; Besedin, I M; Bazhin, A S; Gabdulin, M A; Kolyvanova, S S

2017-09-01

An ointment containing metabolites of Bacillus sp. microorganisms isolated from permafrost samples was applied onto the skin wound of BALB/c mice. Metabolites isolated during culturing of Bacillus sp. at 37°C produced a potent therapeutic effect and promoted wound epithelialization by 30% in comparison with the control (ointment base) and by 20% in comparison with Solcoseryl. Treatment with Bacillus sp. metabolites stimulated predominantly humoral immunity, reduced the time of wound contraction and the volume of scar tissue, and promoted complete hair recovery. These metabolites can be considered as modulators of the wound process with predominance of regeneration mechanisms.

Ermophilane sesquiterpenes from Hawaiian endophytic fungus Chaetoconis sp.FT087

USDA-ARS?s Scientific Manuscript database

Seven sesquiterpene derivatives, including chaetopenoids A–F and dendryphiellin A1, and 6-methyl-(2E,4E, 6S) octadienoic acid were isolated from the culture broth of Chaetoconis sp. FT087. Their structures were determined through the analysis of HRMS and NMR spectroscopic data. The absolute configur...

Energy transfer in Anabaena variabilis filaments adapted to nitrogen-depleted and nitrogen-enriched conditions studied by time-resolved fluorescence.

PubMed

Onishi, Aya; Aikawa, Shimpei; Kondo, Akihiko; Akimoto, Seiji

2017-09-01

Nitrogen is among the most important nutritious elements for photosynthetic organisms such as plants, algae, and cyanobacteria. Therefore, nitrogen depletion severely compromises the growth, development, and photosynthesis of these organisms. To preserve their integrity under nitrogen-depleted conditions, filamentous nitrogen-fixing cyanobacteria reduce atmospheric nitrogen to ammonia, and self-adapt by regulating their light-harvesting and excitation energy-transfer processes. To investigate the changes in the primary processes of photosynthesis, we measured the steady-state absorption and fluorescence spectra and time-resolved fluorescence spectra (TRFS) of whole filaments of the nitrogen-fixing cyanobacterium Anabaena variabilis at 77 K. The filaments were grown in standard and nitrogen-free media for 6 months. The TRFS were measured with a picosecond time-correlated single photon counting system. Despite the phycobilisome degradation, the energy-transfer paths within phycobilisome and from phycobilisome to both photosystems were maintained. However, the energy transfer from photosystem II to photosystem I was suppressed and a specific red chlorophyll band appeared under the nitrogen-depleted condition.

Aluminum effects on uptake and metabolism of phosphorus by the Cyanobacterium Anabaena cylindrica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pettersson, A.; Haellbom, L. Bergman, B.

Aluminum severely affects the growth of the cyanobacterium Anabaena cylindrica and induces symptoms indicating phosphorus starvation. Pre- or post-treating the cells with high (90 micromolar) phosphorus reduces the toxicity of aluminum compared to cells receiving a lower orthophosphate concentration. In this study aluminum (ranging from 9 to 36 micromolar) and phosphorus concentrations were chosen so that the precipitation of insoluble AlPO/sub 4/ never exceeded 10% of the total phosphate concentration. The uptake of /sup 32/P-phosphorus is not disturbed by aluminium either at high (100 micromolar) or low (10 micromolar) concentrations of phosphate. Also, the rapid accumulation of polyphosphate granules inmore » cells exposed to aluminum indicates that the incorporation of phosphate is not disturbed. However, a significant decrease in the mobilization of the polyphosphates is observed, as is a lowered activity of the enzyme acid phosphatase, in aluminum treated cells. We conclude that aluminum acts on the intracellular metabolism of phosphate, which eventually leads to phosphorus starvation rather than on its uptake in the cyanobacterium A. cylindrica.« less

Ultrasonic Characteristics and Cellular Properties of Anabaena Gas Vesicles.

PubMed

Yang, Yaoheng; Qiu, Zhihai; Hou, Xuandi; Sun, Lei

2017-12-01

Ultrasound imaging is a common modality in clinical examination and biomedical research, but has not played a significant role in molecular imaging for lack of an appropriate contrast agent. Recently, biogenic gas vesicles (GVs), naturally formed by cyanobacteria and haloarchaea, have exhibited great potential as an ultrasound molecular imaging probe with a much smaller size (∼100 nm) and improved imaging contrast. However, the basic acoustic and biological properties of GVs remain unclear, which hinders future application. Here, we studied the fundamental acoustic properties of a rod-shaped gas vesicle from Anabaena, a kind of cyanobacterium, including attenuation, oscillation resonance, and scattering, as well as biological behaviors (cellular internalization and cytotoxicity). We found that GVs have two resonance peaks (85 and 120 MHz). We also observed a significant non-linear effect and its pressure dependence as well. Ultrasound B-mode imaging reveals sufficient echogenicity of GVs for ultrasound imaging enhancement at high frequencies. Biological characterization also reveals endocytosis and non-toxicity. Copyright © 2017 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

Trehalose-producing enzymes MTSase and MTHase in Anabaena 7120 under NaCl stress.

PubMed

Asthana, Ravi K; Nigam, Subhasha; Maurya, Archana; Kayastha, Arvind M; Singh, Sureshwar P

2008-05-01

Salt tolerance, a multigenic trait, necessitates knowledge about biosynthesis and function of candidate gene(s) at the cellular level. Among the osmolytes, trehalose biosynthesis in cyanobacteria facing NaCl stress is little understood. Anabaena 7120 filaments exposed to 150 mM: NaCl fragmented and recovered on transfer to -NaCl medium with the increased heterocysts frequency (7%) over the control (4%). Cells failed to retain Na+ beyond a threshold [2.19 mM/cm3 (PCV)]. Whereas NaCl-stressed cells exhibited a marginal rise in K+ (1.1-fold) only at 30 h, for Na+ it was 130-fold at 48 h over cells in control. A time-course study (0-54 h) revealed reduction in intracellular Na+ beyond 48 h [0.80 mM/cm3 (PCV)] suggestive of ion efflux. The NaCl-stressed cells showed differential expression of maltooligosyltrehalose synthase (MTSase; EC 5.4.99.15) and maltooligosyltrehalose trehalohydrolase (MTHase; EC 3.2.1.141) depending on the time and the extent of intracellular Na+ buildup.

DNA Isolation of Microbial Contaminants in Aviation Turbine Fuel via Traditional Polymerase Chain Reaction (PCR) and Direct PCR. Preliminary Results

DTIC Science & Technology

2005-11-01

fuel gauge malfunctions, fuel line and filter plugging, and corrosion. As a result, there is considerable interest in identifying microbial growth ...corrosion. As a result, there is considerable interest in identifying microbial growth and finding strategies to mitigate it. Previous research to... Rhodotorula sp. Yes Yes Trichosporium sp. Yes Trichoderma sp. (viride + others) Yes Yes 4 Table 2. Culturability Determined as a Percentage of

Interleukin-1beta-induced airway hyperresponsiveness enhances substance P in intrinsic neurons of ferret airway.

PubMed

Wu, Z-X; Satterfield, B E; Fedan, J S; Dey, R D

2002-11-01

Interleukin (IL)-1beta causes airway inflammation, enhances airway smooth muscle responsiveness, and alters neurotransmitter expression in sensory, sympathetic, and myenteric neurons. This study examines the role of intrinsic airway neurons in airway hyperresponsiveness (AHR) induced by IL-1beta. Ferrets were instilled intratracheally with IL-1beta (0.3 microg/0.3 ml) or saline (0.3 ml) once daily for 5 days. Tracheal smooth muscle contractility in vitro and substance P (SP) expression in tracheal neurons were assessed. Tracheal smooth muscle reactivity to acetylcholine (ACh) and methacholine (MCh) and smooth muscle contractions to electric field stimulation (EFS) both increased after IL-1beta. The IL-1beta-induced AHR was maintained in tracheal segments cultured for 24 h, a procedure that depletes SP from sensory nerves while maintaining viability of intrinsic airway neurons. Pretreatment with CP-99994, an antagonist of neurokinin 1 receptor, attenuated the IL-1beta-induced hyperreactivity to ACh and MCh and to EFS in cultured tracheal segments. SP-containing neurons in longitudinal trunk, SP innervation of superficial muscular plexus neurons, and SP nerve fiber density in tracheal smooth muscle all increased after treatment with IL-1beta. These results show that IL-1beta-enhanced cholinergic airway smooth muscle contractile responses are mediated by the actions of SP released from intrinsic airway neurons.

Effect of neutral endopeptidase inhibition on substance-P-induced increase in short-circuit current of canine cultured tracheal epithelium.

PubMed

Tamaoki, J; Sakai, N; Isono, K; Kanemura, T; Chiyotani, A; Yamauchi, F; Takizawa, T; Konno, K

1991-01-01

We studied the effect of substance P (SP) on the electric properties of cultured canine tracheal epithelium and its possible modulation by neutral endopeptidase (NEP) by Ussing's short-circuited technique in vitro. Addition of SP (5 x 10(-6) M) to the mucosal side increased short-circuit current (SCC) from 5.1 +/- 0.9 to 10.3 +/- 2.2 microA/cm2 (mean +/- SE; p less than 0.01), which was accompanied by increases in transepithelial potential difference and conductance. The effect of the mucosal SP on SCC was dose-dependent, with the maximal increase from the baseline value being 5.8 +/- 1.0 microA/cm2 observed at 5 x 10(-5) M. The NEP inhibitor phosphoramidon (10(-5) M) did not affect these responses. On the other hand, SCC was not altered by the addition of SP to the submucosal side. However, it was increased dose-dependently in the presence of phosphoramidon (10(-5) M) but not in the presence of captopril, bestatin or leupeptin. This stimulatory effect of submucosal SP was abolished by furosemide, diphenylamine-2-carboxylate and Cl-free medium, but not by amiloride. These results suggest that SP may selectively stimulate Cl secretion across the airway epithelium and that this effect may be modulated by submucosal NEP.

Interspecific cooperation: enhanced growth, attachment and strain-specific distribution in biofilms through Azospirillum brasilense-Pseudomonas protegens co-cultivation.

PubMed

Pagnussat, Luciana A; Salcedo, Florencia; Maroniche, Guillermo; Keel, Christoph; Valverde, Claudio; Creus, Cecilia M

2016-10-01

Plant-growth-promoting bacteria belonging to Azospirillum and Pseudomonas genera are major inhabitants of the rhizosphere. Both are increasingly commercialized as crops inoculants. Interspecific interaction in the rhizosphere is critical for inoculants aptness. The objective of this work was to evaluate Azospirillum and Pseudomonas interaction in mixed biofilms by co-cultivation of the model strains Azospirillum brasilense Sp245 and Pseudomonas protegens CHA0. The results revealed enhanced growth of both strains when co-cultured in static conditions. Moreover, Sp245 biofilm formed in plastic surfaces was increased 2-fold in the presence of CHA0. Confocal microscopy revealed highly structured mixed biofilms showing Sp245 mainly on the bottom and CHA0 towards the biofilm surface. In addition, A. brasilense biofilm was thicker and denser when co-cultured with P. protegens. In a colony-colony interaction assay, Sp245 changed nearby CHA0 producing small colony phenotype, which accounts for a diffusible metabolite mediator; though CHA0 spent medium did not affect Sp245 colony phenotype. Altogether, these results point to a cooperative interaction between A. brasilense Sp245 and P. protegens CHA0 in which both strains increase their static growth and produce structured mixed biofilms with a strain-specific distribution. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[Pigments of green sulfur bacteria isolated from reservoirs of Iavoriv sulfur deposit].

PubMed

Baran, I M; Hudz', S P; Hnatush, S O; Fedorovych, A M

2004-01-01

The enormous amount of hydrogen sulfide (up to 11 mg/ml) is present in the Yavoriv sulfur deposit reservoirs owing to sulfur reductive bacteria activity. As a consequence the ecological situation is badly affected and requires recovering. The biological H2S decomposition by photosynthetic sulfur bacteria, which use the hydrogen sulfide as electron donor during photosynthesis, can be one of the possible ways of this toxic substance destruction. The qualitative and quantitative analysis of photosynthetic pigments composition that derived from green photosynthesizing sulfur bacteria from reservoirs of Yavoriv sulfur deposit is carried out. It was fixed that Pelodictyon sp., Chlorobium sp. and isolated consortia "Pelochromatium sp." contain the bacteriochlorophyll c and d. All the isolated cultures contained bacteriochlorophyll a in trace amounts. The obtained photosynthetic pigments (bacteriochlorophylls, carotenoids) were recognized by their absorption spectra in the visible and far-red region and by their quantity. The difference was not essential. All investigated cultures of isolated bacteria contain some carotenoid the Chlorobium sp. and obtained consortia possesses isorenieratene. The absorption maxima of extracted pigments from young cultures of isolated green sulfur bacteria are more definitely displayed than those from old cultures. Investigations of phototrophic sulfur bacteria were carried out in Ukraine up to now. Ecological problem that occurred in the Yavoriv sulfur deposit as a result of the deposit exploitation caused a necessity of the investigation of photosynthetic sulfur bacteria and bacterial photosynthesis mechanism. The photosynthetic pigments nature identification will promote the fast and precise identification of the new forms of photosynthetic sulfur bacteria and will extend our knowledge about their role in the anoxygenic photosynthesis.

Hematodinium spp. infections in wild and cultured populations of marine crustaceans along the coast of China.

PubMed

Wang, Jin-Feng; Li, Meng; Xiao, Jie; Xu, Wen-Jun; Li, Cai-Wen

2017-05-11

The parasitic dinoflagellate Hematodinium spp. infects a broad range of marine crustaceans. Its epidemics have impacted wild populations of various commercial fishery species around the world and the sustainability of mariculture in China. To study the epidemiology of Hematodinium spp. in marine crustaceans along the coast of China, we conducted a broad survey of wild and cultured stocks of major crustacean species in 2013 to 2015. Hematodinium sp. infections were identified in wild stocks of Portunus trituberculatus from Huludao, Laizhou, Qingdao, Yangtze River Estuary and Zhoushan, and Scylla paramamosain from Shantou; and cultured stocks of Portunus trituberculatus and Penaeus monodon from a polyculture pond in Qingdao. In the polyculture pond, Hematodinium sp. infections were observed in Portunus trituberculatus from June until October, with peak prevalence (up to 90%) observed in late July to early August. Furthermore, Hematodinium sp. infection was identified for the first time in the giant tiger prawn Penaeus monodon in the polyculture system during the disease outbreak. Phylogenetic analysis indicated that the Hematodinium isolate infecting Penaeus monodon was identical to the isolate infecting the co-cultured Portunus trituberculatus, and it was grouped into H. perezi genotype II together with the other isolates reported in China. The Hematodinium sp. isolated from Portunus trituberculatus appeared to have similar life stages as the H. perezi genotype III isolated from the American blue crab Callinectes sapidus. Our study indicates that outbreaks of Hematodinium disease can be a significant threat to the widely used polyculture system for decapods in China that may be particularly vulnerable to such generalist pathogens.

Fluctuation of Bacteria on Bleb Surface After Trabeculectomy With Adjunctive Mitomycin C.

PubMed

Takahashi, Nobumichi; Sawada, Akira; Mochizuki, Kiyofumi; Katada, Toshihiko; Yamamoto, Tetsuya

2016-05-01

To determine whether the bacterial and floral patterns on the bleb surface are affected by the season in eyes that had undergone trabeculectomy with adjunctive mitomycin C. Forty-four glaucoma patients who had an avascular or a hypovascular cystic filtering bleb were studied. Swabs of the bleb surface were taken 4 times in 1 year. The samples were cultured, and all organisms isolated were identified and tested for antibiotic sensitivity and resistance. Of the 176 specimens, 48 tested positive in cultures. Out of the 44 glaucoma eyes that had undergone trabeculectomy, 30 (68.2%) eyes were culture positive. A total of 58 strains were isolated. The organisms isolated were 22 strains of Staphylococcus epidermidis, 21 strains of Propionibacterium acnes, 8 strains of Corynebacterium sp., 5 strains of Staphylococcus sp., and 1 strain of both Neisseria sp., and Candida parapsilosis. Fifteen eyes had a positive culture ≥2 times, and in 10 of these eyes, the same strain was isolated. There was no resistance to vancomycin by S. epidermidis, P. acnes, and Corynebacterium sp. All of the isolates of S.epidermidis were sensitive to minocycline and amikacin. The rate of bacterial detection in the spring was 13.6%, summer was 20.5%, autumn was 45.5%, and winter was 29.5%. The increase in the incidence of bacterial presence during autumn was significant (P=0.006; the Fisher exact probability test). It is not rare to detect the bacterial organisms on the bleb surface in glaucomatous eyes that had undergone trabeculectomy. The prevalence varied with the season and was highest in the autumn.

Production of fungal antibiotics using polymeric solid supports in solid-state and liquid fermentation.

PubMed

Bigelis, Ramunas; He, Haiyin; Yang, Hui Y; Chang, Li-Ping; Greenstein, Michael

2006-10-01

The use of inert absorbent polymeric supports for cellular attachment in solid-state fungal fermentation influenced growth, morphology, and production of bioactive secondary metabolites. Two filamentous fungi exemplified the utility of this approach to facilitate the discovery of new antimicrobial compounds. Cylindrocarpon sp. LL-Cyan426 produced pyrrocidines A and B and Acremonium sp. LL-Cyan416 produced acremonidins A-E when grown on agar bearing moist polyester-cellulose paper and generated distinctly different metabolite profiles than the conventional shaken or stationary liquid fermentations. Differences were also apparent when tenfold concentrated methanol extracts from these fermentations were tested against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria, and zones of inhibition were compared. Shaken broth cultures of Acremonium sp. or Cylindrocarpon sp. showed complex HPLC patterns, lower levels of target compounds, and high levels of unwanted compounds and medium components, while agar/solid support cultures showed significantly increased yields of pyrrocidines A and B and acremonidins A-E, respectively. This method, mixed-phase fermentation (fermentation with an inert solid support bearing liquid medium), exploited the increase in surface area available for fungal growth on the supports and the tendency of some microorganisms to adhere to solid surfaces, possibly mimicking their natural growth habits. The production of dimeric anthraquinones by Penicillium sp. LL-WF159 was investigated in liquid fermentation using various inert polymeric immobilization supports composed of polypropylene, polypropylene cellulose, polyester-cellulose, or polyurethane. This culture produced rugulosin, skyrin, flavomannin, and a new bisanthracene, WF159-A, after fermentation in the presence and absence of polymeric supports for mycelial attachment. The physical nature of the different support systems influenced culture morphology and relative metabolite yields, as determined by HPLC analysis and measurement of antimicrobial activity. The application of such immobilized-cell fermentation methods under solid and liquid conditions facilitated the discovery of new antibiotic compounds, and offers new approaches to fungal fermentation for natural product discovery.

Synergistic Degradation of Linuron by a Bacterial Consortium and Isolation of a Single Linuron-Degrading Variovorax Strain

PubMed Central

Dejonghe, Winnie; Berteloot, Ellen; Goris, Johan; Boon, Nico; Crul, Katrien; Maertens, Siska; Höfte, Monica; De Vos, Paul; Verstraete, Willy; Top, Eva M.

2003-01-01

The bacterial community composition of a linuron-degrading enrichment culture and the role of the individual strains in linuron degradation have been determined by a combination of methods, such as denaturing gradient gel electrophoresis of the total 16S rRNA gene pool, isolation and identification of strains, and biodegradation assays. Three strains, Variovorax sp. strain WDL1, Delftia acidovorans WDL34, and Pseudomonas sp. strain WDL5, were isolated directly from the linuron-degrading culture. In addition, subculture of this enrichment culture on potential intermediates in the degradation pathway of linuron (i.e., N,O-dimethylhydroxylamine and 3-chloroaniline) resulted in the isolation of, respectively, Hyphomicrobium sulfonivorans WDL6 and Comamonas testosteroni WDL7. Of these five strains, only Variovorax sp. strain WDL1 was able to use linuron as the sole source of C, N, and energy. WDL1 first converted linuron to 3,4-dichloroaniline (3,4-DCA), which transiently accumulated in the medium but was subsequently degraded. To the best of our knowledge, this is the first report of a strain that degrades linuron further than the aromatic intermediates. Interestingly, the rate of linuron degradation by strain WDL1 was lower than that for the consortium, but was clearly increased when WDL1 was coinoculated with each of the other four strains. D. acidovorans WDL34 and C. testosteroni WDL7 were found to be responsible for degradation of the intermediate 3,4-DCA, and H. sulfonivorans WDL6 was the only strain able to degrade N,O-dimethylhydroxylamine. The role of Pseudomonas sp. strain WDL5 needs to be further elucidated. The degradation of linuron can thus be performed by a single isolate, Variovorax sp. strain WDL1, but is stimulated by a synergistic interaction with the other strains isolated from the same linuron-degrading culture. PMID:12620840

Francisella marina sp. nov., etiologic agent of systemic disease in cultured spotted rose snapper (Lutjanus guttatus) in Central America.

PubMed

Soto, Esteban; Griffin, Matt J; Morales, Juan Alberto; Barquero Calvo, Elías; de Alexandre Sebastião, Fernanda; Lopez Porras, Adrián; Víquez-Rodríguez, Xindy; Reichley, Stephen R; Rosser, Thomas G; Ware, Cynthia; Byrne, Barbara A; García, Julio C; LaFrentz, Benjamin R; Camus, Alvin C

2018-06-18

Historically, piscine francisellosis in various warm, temperate and coldwater fish hosts has been attributed to Francisella noatunensis From 2015-2016, an undescribed Francisella sp. was recovered during mortality events in cultured spotted rose snapper ( Lutjanus guttatus ) off the Pacific coast of Central America. Despite high mortality and emaciation, limited gross findings were observed in affected fish. Histological examination revealed multifocal granulomatous lesions, with the presence of numerous small, pleomorphic coccobacilli, predominantly in the peritoneum, spleen, kidneys, liver, pancreas, heart, and intestine. Sequencing of an ∼1400 bp fragment of the 16S rRNA gene demonstrated these isolates to be most similar (99.9% identity) to Francisella sp. isolate TX077308 cultured from sea water in the Gulf of Mexico, while sharing <99% similarity to other Fransicella spp. Biochemical analysis, multi-locus sequence comparisons of select housekeeping-genes, repetitive extragenic palindromic PCR fingerprinting, matrix-assisted laser-desorption ionization-time of flight mass spectrometry, and fatty acid methyl esters analysis revealed marked differences between these isolates and other described members of the genus. Koch's postulates were fulfilled by experimental intracoelomic injection and immersion trials using Nile ( Oreochromis niloticus ) and blue tilapia ( O. aureus ). Based on observed phenotypic and genotypic differences from recognized Francisella spp., the name Francisella marina sp. nov. (NRRL # B-65518) is proposed to accommodate these novel strains. Importance Finfish aquaculture is the fastest growing global food production sector. Infectious disease, particularly emergent pathogens, pose a significant threat to established and nascent aquaculture industries worldwide. Herein, we characterize a novel pathogen isolated from mortality events in cultured spotted rose snapper in Central America. The bacteria recovered from these outbreaks were genetically and phenotypically dissimilar from other known Francisella spp. from fish, representing a previously unrecognized member of the genus Francisella , for which the name Francisella marina sp. nov. is proposed. Copyright © 2018 American Society for Microbiology.

Rahnella sp. strain EK12: Cell surface properties and diesel oil biodegradation after long-term contact with natural surfactants and diesel oil.

PubMed

Smułek, Wojciech; Zdarta, Agata; Guzik, Urszula; Dudzińska-Bajorek, Beata; Kaczorek, Ewa

2015-07-01

The changes in cell surface properties of Rahnella sp. strain EK12 and modifications in genetic material after long-term contact with saponins and rhamnolipids, were investigated. Rhamnolipids caused a decrease of hydrophobicity in liquid cultures compared with saponins. On the other hand, in cultures with rhamnolipids, the addition of diesel oil results in a rapid rise of cell surface hydrophobicity. The similar effect was not so significant in the presence of saponins. For the bacteria grown in the presence of saponins or rhamnolipids, but without diesel oil, the ratio of unsaturated to saturated fatty acids decreased, in comparison to the control culture. The differences observed in hydrophobicity, zeta potential and fatty acids profiles, indicated various mechanisms of an interaction between a surfactant and a bacterial cells. The results have also shown an impact of the long-term contact on changes in genetic material of Rahnella sp. strain EK12 cells. Moreover, the presence of saponins led to significant increase of diesel oil biodegradation. Copyright © 2015 Elsevier GmbH. All rights reserved.

The effect of thallus spreading method on productivity of Gracilaria sp. culture

NASA Astrophysics Data System (ADS)

Hidayatulbaroroh, R.; Nurhudah, M.; Edy, M. H.; Suharyadi

2018-04-01

The aim of this study was to determine growth of (Gracilaria sp.) with different spreading time of thallus. The study was conducted from March to April 2017 in pond located in Domas Village, Serang Region, Banten Province. The experiment followed completely randomized design with the treatment of different time on spreading of seaweed thallus during the culture period (45 days). Treatments were without spreading (as control), spreading every 2 weeks, and spreading every 3 weeks. The observed variables were weight of seaweed thallus and several water quality parameters. Analysis of seaweed weight used ANOVA test and Tukey HSD test. The results showed that the spread seaweed thallus had a significant effect on weight gain in 0.05 level. It used 100 gram Gracilaria sp. as initial weight, treatment without spreading thallus produced 508 gram, spreading every 2 weeks produced 906 gram and spreading every 3 weeks produced 790 gram. Based on the weight gain of thallus, seaweed culture by spreading thallus every 3 weeks and 2 weeks seem to be able to increase productivity by 56 % and 78 %, respectively.

Evaluation of insecticidal activity of a bacterial strain, Serratia sp. EML-SE1 against diamondback moth.

PubMed

Jeong, Hyung Uk; Mun, Hye Yeon; Oh, Hyung Keun; Kim, Seung Bum; Yang, Kwang Yeol; Kim, Iksoo; Lee, Hyang Burm

2010-08-01

To identify novel bioinsecticidal agents, a bacterial strain, Serratia sp. EML-SE1, was isolated from a dead larva of the lepidopteran diamondback moth (Plutella xylostella) collected from a cabbage field in Korea. In this study, the insecticidal activity of liquid cultures in Luria-Bertani broth (LBB) and nutrient broth (NB) of a bacterial strain, Serratia sp. EML-SE1 against thirty 3rd and 4th instar larvae of the diamondback moth was investigated on a Chinese cabbage leaf housed in a round plastic cage (Ø 10 x 6 cm). 72 h after spraying the cabbage leaf with LBB and NB cultures containing the bacterial strain, the mortalities of the larvae were determined to be 91.7% and 88.3%, respectively. In addition, the insecticidal activity on potted cabbage containing 14 leaves in a growth cage (165 x 83 x 124 cm) was found to be similar to that of the plastic cage experiment. The results of this study provided valuable information on the insecticidal activity of the liquid culture of a Serratia species against the diamondback moth.

Amino acid residues in Anabaena ferredoxin crucial to interaction with ferredoxin-NADP+ reductase: site-directed mutagenesis and laser flash photolysis.

PubMed

Hurley, J K; Salamon, Z; Meyer, T E; Fitch, J C; Cusanovich, M A; Markley, J L; Cheng, H; Xia, B; Chae, Y K; Medina, M

1993-09-14

Ferredoxin (Fd) functions in photosynthesis to transfer electrons from photosystem I to ferredoxin-NADP+ reductase (FNR). We have made several site-directed mutants of Anabaena 7120 Fd and have used laser flash photolysis to investigate the effects of these mutations on the kinetics of reduction of oxidized Fd by deazariboflavin semiquinone (dRfH.) and the reduction of oxidized Anabaena FNR by reduced Fd. None of the mutations influenced the second-order rate constant for dRfH. reduction by more than a factor of 2, suggesting that the ability of the [2Fe-2S] cluster to participate in electron transfer was not seriously affected. In contrast, a surface charge reversal mutation, E94K, resulted in a 20,000-fold decrease in the second-order rate constant for electron transfer from Fd to FNR, whereas a similar mutation at an adjacent site, E95K, produced little or no change in reaction rate constant compared to wild-type Fd. Such a dramatic difference between contiguous surface mutations suggests a very precise surface complementarity at the protein-protein interface. Mutations introduced at F65 (F65I and F65A) also decreased the rate constant for the Fd/FNR electron transfer reaction by more than 3 orders of magnitude. Spectroscopic and thermodynamic measurements with both the E94 and F65 mutants indicated that the kinetic differences cannot be ascribed to changes in gross conformation, redox potential, or FNR binding constant but rather reflect the protein-protein interactions that control electron transfer. Several mutations at other sites in the vicinity of E94 and F65 (R42, T48, D68, and D69) resulted in little or no perturbation of the Fd/FNR interaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Engineering Pichia pastoris for Efficient Production of a Novel Bifunctional Strongylocentrotus purpuratus Invertebrate-Type Lysozyme.

PubMed

Huang, Peng; Shi, Jinlei; Sun, Qingwen; Dong, Xianping; Zhang, Ning

2018-04-13

Lysozymes are known as ubiquitously distributed immune effectors with hydrolytic activity against peptidoglycan, the major bacterial cell wall polymer, to trigger cell lysis. In the present study, the full-length cDNA sequence of a novel sea urchin Strongylocentrotus purpuratus invertebrate-type lysozyme (sp-iLys) was synthesized according to the codon usage bias of Pichia pastoris and was cloned into a constitutive expression plasmid pPIC9K. The resulting plasmid, pPIC9K-sp-iLys, was integrated into the genome of P. pastoris strain GS115. The bioactive recombinant sp-iLys was successfully secreted into the culture broth by positive transformants. The highest lytic activity of 960 U/mL of culture supernatant was reached in fed-batch fermentation. Using chitin affinity chromatography and gel-filtration chromatography, recombinant sp-iLys was produced with a yield of 94.5 mg/L and purity of > 99%. Recombinant sp-iLys reached its peak lytic activity of 8560 U/mg at pH 6.0 and 30 °C and showed antimicrobial activities against Gram-negative bacteria (Vibrio vulnificus, Vibrio parahemolyticus, and Aeromonas hydrophila) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). In addition, recombinant sp-iLys displayed isopeptidase activity which reached the peak at pH 7.5 and 37 °C with the presence of 0.05 M Na + . In conclusion, this report describes the heterologous expression of recombinant sp-iLys in P. pastoris on a preparative-scale, which possesses lytic activity and isopeptidase activity. This suggests that sp-iLys might play an important role in the innate immunity of S. purpuratus.

Elicitation of gymnemic acid production in cell suspension cultures of Gymnema sylvestre R.Br. through endophytic fungi.

PubMed

Netala, Vasudeva Reddy; Kotakadi, Venkata Subbaiah; Gaddam, Susmila Aparna; Ghosh, Sukhendu Bikash; Tartte, Vijaya

2016-12-01

The enhancement of plant secondary metabolite production in cell suspension cultures through biotic or abiotic elicitation has become a potential biotechnological approach for commercialization or large-scale production of bioactive compounds. Gymnema sylvestre R.Br. is an important medicinal plant, rich in a group of oleanane triterpenoid saponins called gymnemic acid, well known for its anti-diabetic activity. Two endophytic fungal strains were isolated from the leaves of G. sylvestre and identified as Polyancora globosa and Xylaria sp. based on the PCR amplification and internal transcribed spacer (ITS 1-5.8S-ITS 2) sequencing of 18S rRNA gene. The process of elicitation of cell suspension cultures of G. sylvestre with dried powder of fungal mycelia (DPFM) and extracellular culture filtrate (ECF) of endophytic fungi consistently enhanced the accumulation of gymnemic acid and the DPFM was proved to be an effective elicitor when compared to the ECF. The DPFM elicited the gymnemic acid content in the range of 2.57-10.45-fold, while the ECF elicited the gymnemic acid content in the range of 2.39-7.8-fold. P. globosa, a novel and a rare endophytic fungal strain, has shown a great influence on the production of gymnemic acid. Cell suspension cultures elicited with DPFM of P. globosa produced higher amount of gymnemic acid content (124.23 mg/g dried cell weight) compared to the cultures elicited with DPFM of Xylaria sp. (102.24 mg/g DCW). But the cultures treated with consortium of DPFM of both fungi showed great influence on the production of gymnemic acid (139.98 mg/g DCW) than the cultures treated with DPFM alone. Similarly, cultures treated with consortium of ECF of both fungi produced more gymnemic acid content (94.86 mg/g DCW) compared with cultures treated with ECF of Xylaria sp. (77.93 mg/g DCW) and ECF of P. globosa (78.65 mg/g DCW) alone.

Endophytic bacteria in plant tissue culture: differences between easy- and difficult-to-propagate Prunus avium genotypes.

PubMed

Quambusch, Mona; Pirttilä, Anna Maria; Tejesvi, Mysore V; Winkelmann, Traud; Bartsch, Melanie

2014-05-01

The endophytic bacterial communities of six Prunus avium L. genotypes differing in their growth patterns during in vitro propagation were identified by culture-dependent and culture-independent methods. Five morphologically distinct isolates from tissue culture material were identified by 16S rDNA sequence analysis. To detect and analyze the uncultivable fraction of endophytic bacteria, a clone library was established from the amplified 16S rDNA of total plant extract. Bacterial diversity within the clone libraries was analyzed by amplified ribosomal rDNA restriction analysis and by sequencing a clone for each identified operational taxonomic unit. The most abundant bacterial group was Mycobacterium sp., which was identified in the clone libraries of all analyzed Prunus genotypes. Other dominant bacterial genera identified in the easy-to-propagate genotypes were Rhodopseudomonas sp. and Microbacterium sp. Thus, the community structures in the easy- and difficult-to-propagate cherry genotypes differed significantly. The bacterial genera, which were previously reported to have plant growth-promoting effects, were detected only in genotypes with high propagation success, indicating a possible positive impact of these bacteria on in vitro propagation of P. avium, which was proven in an inoculation experiment. © The Author 2014. Published by Oxford University Press. All rights reserved.

Qualitatively Monitoring Binding and Expression of the Transcription Factors Sp1 and NFI as a Useful Tool to Evaluate the Quality of Primary Cultured Epithelial Stem Cells in Tissue Reconstruction.

PubMed

Le-Bel, Gaëtan; Ghio, Sergio Cortez; Larouche, Danielle; Germain, Lucie; Guérin, Sylvain L

2018-05-27

Electrophoretic mobility shift assays and Western blots are simple, efficient, and rapid methods to study DNA-protein interactions and protein expression, respectively. Primary cultures and subcultures of epithelial cells are widely used for the production of tissue-engineered substitutes and are gaining popularity as a model for gene expression studies. The preservation of stem cells through the culture process is essential to produce high quality substitutes. However, the increase in the number of cell passages is associated with a decrease in their ability to proliferate until senescence is reached. This process is likely to be mediated by the altered expression of nuclear-located transcription factors such as Sp1 and NFI, whose expression has been documented to be required for cell adhesion, migration, and differentiation. In some of our recent studies, we observed a correlation between reconstructed tissues exhibiting poor histological and structural characteristics and a low expression of Sp1 in their constituting epithelial cells. Therefore, monitoring both the expression and DNA binding of these transcription factors in human skin and corneal epithelial cells is a useful tool for characterizing the quality of primary cultured epithelial cells.

Morphology, antigenicity, and nucleic acid content of the Bacteroides sp. used in the culture of Entamoeba histolytica.

PubMed

Albach, R A; Shaffer, J G; Watson, R H

1965-10-01

Albach, Richard A. (Lutheran General Hospital, Park Ridge, Ill.), James G. Shaffer, and Robert H. Watson. Morphology, antigenicity, and nucleic acid content of the Bacteroides sp. used in the culture of Entamoeba histolytica. J. Bacteriol. 90:1045-1053. 1965.-Certain changes in morphology, antigenicity, and nucleic acid content that occur in a culture of Bacteroides sp. in the presence of penicillin G in CLG medium are described. This "variant" is one of seven recovered in several laboratories, all of which are descendants of the original Bacteroides isolated by Shaffer and Frye. Penicillin-inhibited cells of this culture are currently being used in the routine propagation of Entamoeba histolytica in CLG medium. Evidence is presented for the loss of ability to react with antibody in these penicillin-inhibited bacteria in CLG medium, when studied by fluorescent-antibody techniques. The implications of the antigenic changes observed as they pertain to similar antigenic studies of the amoebas are discussed. A pronounced reduction in the ribonucleic acid (RNA) content of such penicillin-inhibited cells was also observed. The potential importance of the changes that occur in the RNA of these cells with respect to considerations of the growth requirements of the amoebas is also discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stochaj, W.R.; Grossman, A.R.

One- and two-dimensional sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunological analyses were used to visualize differences in polypeptides synthesized by Symbiodinium sp. from the anemone Aiptasia pallida when grown in the cultured and endosymbiotic states (freshly isolated zooxanthellae). Surprisingly, a comparison of proteins in cultured and endosymbiotic Symbiodinium sp. revealed only four major polypeptides with similar isoelectric and molecular mass characteristics. Using monospecific antibodies, we demonstrated differences in specific proteins synthesized by the dinoflagellate in the two different growth states. The dimeric, 14 kDa form of the peripheral membrane peridinin-chlorophyll a binding protein predominates under endosymbiotic conditions, whereas the monomeric, 35more » kDa form predominates under the culture conditions used in this study. Antibodies to form II ribulose-1,5-bisphosphate carboxylase revealed 62 and 60 kDa forms of this protein in the alga grown as an endosymbiont and in culture, respectively. Differences in the integral membrane peridinin-chlorophyll a-c-binding proteins were also observed. These results demonstrate that there are major changes in the populations of proteins synthesized by Symbiodinium sp. in response to the conditions in hospite. Such changes may reflect a developmental switch that tailors the physiology of the alga to the conditions encountered in the endosymbiotic state. 77 refs., 6 figs.« less

Outdoor Cultivation of Marine Diatoms for Year-Round Production of Biofuels.

PubMed

Matsumoto, Mitsufumi; Nojima, Daisuke; Nonoyama, Tomomi; Ikeda, Kiichi; Maeda, Yoshiaki; Yoshino, Tomoko; Tanaka, Tsuyoshi

2017-03-25

Biofuel production using microalgae is believed to have the advantage of continuous year-round production over crop plants, which have strong seasonality. However, actual year-round production of microalgal lipids using outdoor mass cultivation has rarely been demonstrated. In our previous study, it was demonstrated that the oleaginous diatom, Fistulifera solaris , was culturable in outdoor bioreactors from spring to autumn, whereas biomass and lipid production in winter failed because F. solaris did not grow below 15 °C. Therefore, another candidate strain that is culturable in winter is required. In this study, a cold-tolerant diatom, Mayamaea sp. JPCC CTDA0820, was selected as a promising candidate for biofuel production in winter. Laboratory-scale characterization revealed that this diatom was culturable at temperatures as low as 10 °C. Subsequently, F. solaris (April-October) and Mayamaea sp. JPCC CTDA0820 (November-March) were cultured in outdoor open-pond bioreactors, wherein year-round production of diatom lipids was successfully demonstrated. The maximal values of areal productivities of biomass and lipids reached to 9.79 and 1.80 g/(m² day) for F. solaris , and 8.62 and 0.92 g/(m² day) for Mayamaea sp. JPCC CTDA0820, respectively. With the combined use of these two diatom species, stable year-round production of microalgal lipids became possible.

Formation of methyl mercury by bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamdy, M.K.; Noyes, O.R.

1975-09-01

Twenty-three Hg/sup 2 +/-resistant cultures were isolated from sediment of the Savannah River in Georgia; of these, 14 were gram-negative short rods belonging to the genera Escherichia and Enterobacter, six were gram-positive cocci (three Staphylococcus sp. and three Streptococcus sp.) and three were Bacillus sp. All the Escherichia, Enterobacter, and the Bacillus strain were more resistant to Hg/sup 2 +/ than the strains of staphylococci and streptococci. Adaptation using serial dilutions and concentration gradient agar plate techniques showed that it was possible to select a Hg/sup 2 +/-resistant strain from a parent culture identified as Enterobacter aerogenes. This culture resistedmore » 1,200 ..mu..g of Hg/sup 2 +/ per ml of medium and produced methyl mercury from HgCl/sub 2/, but was unable to convert Hg/sup 2 +/ to volatile elemental mercury (Hg/sup 0/). Under constant aeration (i.e., submerged culture), slightly more methyl mercury was formed than in the absence of aeration. Production of methyl mercury was cycle in nature and slightly decreased if DL-homocysteine was present in media, but increased with methylcobalamine. It is concluded that the bacterial production of methyl mercury may be a means of resistance and detoxification against mercurials in which inorganic Hg/sup 2 +/ is converted to organic form and secreted into the environment.« less

Growth, Toxin Production and Allelopathic Effects of Pseudo-nitzschia multiseries under Iron-Enriched Conditions

PubMed Central

Sobrinho, Bruna Fernanda; de Camargo, Luana Mocelin; Sandrini-Neto, Leonardo; Kleemann, Cristian Rafael; Machado, Eunice da Costa; Mafra, Luiz Laureno

2017-01-01

In order to assess the effects of Fe-enrichment on the growth and domoic acid (DA) production of the toxigenic diatom Pseudo-nitzschia multiseries, static cultures that received the addition of different iron (Fe) concentrations were maintained for 30 days. Intra- and extracellular DA concentrations were evaluated over time, and growth and chain-formation were compared to those of non-toxic diatoms, Bacillaria sp. Growth rates of P. multiseries (μ = 0.45–0.73 d−1) were similar among cultures containing different Fe concentrations. Likewise, the similar incidence and length of P. multiseries stepped cell chains (usually 2–4; up to 8-cell long) among the treatments reinforces that the cultures were not growth-inhibited under any condition tested, suggesting an efficient Fe acquisition mechanism. Moreover, DA concentrations were significantly higher under the highest Fe concentration, indicating that Fe is required for toxin synthesis. Bacillaria sp. reached comparable growth rates under the same Fe concentrations, except when the dissolved cell contents from a P. multiseries culture was added. The 50–70% reduction in cell density and 70–90% decrease in total chlorophyll-a content of Bacillaria sp. at early stationary growth phase indicates, for the first time, an allelopathic effect of undetermined compounds released by Pseudo-nitzschia to another diatom species. PMID:29064395

Growth, Toxin Production and Allelopathic Effects of Pseudo-nitzschia multiseries under Iron-Enriched Conditions.

PubMed

Sobrinho, Bruna Fernanda; de Camargo, Luana Mocelin; Sandrini-Neto, Leonardo; Kleemann, Cristian Rafael; Machado, Eunice da Costa; Mafra, Luiz Laureno

2017-10-24

In order to assess the effects of Fe-enrichment on the growth and domoic acid (DA) production of the toxigenic diatom Pseudo-nitzschia multiseries , static cultures that received the addition of different iron (Fe) concentrations were maintained for 30 days. Intra- and extracellular DA concentrations were evaluated over time, and growth and chain-formation were compared to those of non-toxic diatoms, Bacillaria sp. Growth rates of P. multiseries (μ = 0.45-0.73 d -1 ) were similar among cultures containing different Fe concentrations. Likewise, the similar incidence and length of P. multiseries stepped cell chains (usually 2-4; up to 8-cell long) among the treatments reinforces that the cultures were not growth-inhibited under any condition tested, suggesting an efficient Fe acquisition mechanism. Moreover, DA concentrations were significantly higher under the highest Fe concentration, indicating that Fe is required for toxin synthesis. Bacillaria sp. reached comparable growth rates under the same Fe concentrations, except when the dissolved cell contents from a P. multiseries culture was added. The 50-70% reduction in cell density and 70-90% decrease in total chlorophyll-a content of Bacillaria sp. at early stationary growth phase indicates, for the first time, an allelopathic effect of undetermined compounds released by Pseudo-nitzschia to another diatom species.

A Verhulst model for microalgae Botryococcus sp. growth and nutrient removal in wastewater

NASA Astrophysics Data System (ADS)

Jamaian, Siti Suhana; Bakeri, Noorhadila Mohd; Sunar, Norshuhaila Mohamed; Gani, Paran

2017-08-01

Microalgae Botryococcus sp. is a colonial green alga found in lakes and reservoirs in Malaysia. Previous studies reported that the potential of Botryococcus sp. photosynthesis as a source of fuel. The Botryococcus sp. contains hydrocarbon up to 75% of dry weight, which can be converted into petrol, diesel or turbine fuel or other liquid or gaseous hydrocarbons. Recently, an experimental study was conducted on phycoremediation technology for wastewater using Botryococcus sp. The phycoremediation technology is useful to remove the excess of nutrients such as nitrogen, phosphorus and also have the ability to remove various pollutants from wastewater. This research implements the Verhulst model to estimate the nutrient removal by microalgae Botryococcus sp. from the wastewater. This model has been validated with the experiments of microalgae Botryococcus sp. grown in domestic and palm oil wastewater. The results suggested that microalgae Botryococcus sp. could be cultured in domestic and palm oil wastewater while nutrients are reduced from these wastewaters.

Isolation of Corynebacterium tuscaniae sp. nov. from Blood Cultures of a Patient with Endocarditis

PubMed Central

Riegel, Philippe; Creti, Roberta; Mattei, Romano; Nieri, Alfredo; von Hunolstein, Christina

2006-01-01

A strain of an unknown coryneform bacterium was repeatedly isolated in pure culture from the blood of a patient affected by endocarditis. Comparative 16S rRNA gene sequence analysis revealed that this isolate represented a new subline within the genus Corynebacterium. This new taxon can be identified by the presence of corynomycolic acids and its enzymatic activities and fermentation of sugars. Acid production from glucose and maltose, pyrazinamidase and alkaline phoshatase activities, and hippurate hydrolysis were the most characteristic phenotypic features of the bacterium. On the basis of both phenotypic and phylogenetic evidence, it is proposed that this isolate be classified as a novel species, Corynebacterium tuscaniae sp. nov. The type strain, ISS-5309, has been deposited in the American Type Culture Collection (ATCC BAA-1141) and in the Culture Collection of the University of Göteborg (CCUG 51321). PMID:16455875

Sterilisation of Hydroponic Culture Solution Contaminated by Fungi using an Atmospheric Pressure Corona Discharge

NASA Astrophysics Data System (ADS)

Mizukami, Kohji; Satoh, Kohki; Kanayama, Hiroshi; Itoh, Hidenori; Tagashira, Hiroaki; Shimozuma, Mitsuo; Okamoto, Hiroyuki; Takasaki, Satoko; Kinoshita, Muneshige

The hydroponic culture solution contaminated by fungi is sterilised by a DC corona discharge, and the sterilisation characteristics are investigated in this work. A DC streamer corona discharge is generated at atmospheric pressure in air between needle clusters and a water bath containing contaminated solution by fungus such as Fusarium oxysporum f. sp. spinaciae or Fusarium sp.. It is found that the fungi are killed by the exposure of the corona discharge, and that the death rates of the fungi chiefly depend on the concentration of the hydroponic culture solutions. It is also found that the number densities of the fungi decrease exponentially with the energy expenditure of the corona discharge, and that damping coefficients of the fungi densities depend on the concentration of the hydroponic culture solutions. This suggests that the fungi are chiefly inactivated by electroporation.

Mycoplasma insons sp. nov., a twisted mycoplasma from green iguanas (Iguana iguana)

PubMed Central

May, Meghan; Ortiz, G. Javier; Wendland, Lori D.; Rotstein, David S.; Relich, Ryan F.; Balish, Mitchell F.; Brown, Daniel R.

2008-01-01

Mycoplasma insons sp. nov., first cultured from the choanae and tracheae of healthy green iguanas (Iguana iguana) from El Salvador, was readily distinguished from all previously described mollicutes and assigned to the Mycoplasma fastidiosum phylogenetic cluster by 16S rRNA gene sequence comparisons. Growth inhibition assays distinguished the isolates serologically from the other two members of that cluster. Many M. insons cells exhibit a remarkable twisted rod morphology despite lacking a cell wall. The organism is nonmotile, produces acid from glucose, but does not hydrolyze arginine, esculin, or urea. Mycoplasma insons 16S rRNA gene was also detected by PCR in packed blood cells from culture-negative iguanas. The type strain I17P1T has been deposited with the Mollicutes Collection at Purdue University and with the American Type Culture Collection (ATCC BAA-1435) in the USA. A limited number of cultures generated by the authors have also been deposited with the Culture Collection, University of Göteborg, in Sweden (CCUG 53461). PMID:17697083

Quinolactacins A, B and C: novel quinolone compounds from Penicillium sp. EPF-6. I. Taxonomy, production, isolation and biological properties.

PubMed

Kakinuma, N; Iwai, H; Takahashi, S; Hamano, K; Yanagisawa, T; Nagai, K; Tanaka, K; Suzuki, K; Kirikae, F; Kirikae, T; Nakagawa, A

2000-11-01

Quinolactacins A (1), B (2) and C (3), novel quinolone antibiotics have been found from the cultured broth of a fungal strain isolated from the larvae of the mulberry pyralid Margaronia pyloalis Welker). The fungal strain, EPF-6 was identified as Penicillium sp. from its morphological characteristics. Quinolactacins were obtained from the culture medium by solvent extraction and chromatographic purification. Compound 1 showed inhibitory activity against tumor necrosis factor (TNF) production induced by murine peritoneal macrophages and macrophage-like J774.1 cells stimulated with lipopolysaccharide (LPS).

Cross-cultural sex differences in situational triggers of aggressive responses.

PubMed

Zajenkowska, Anna; Mylonas, Kostas; Lawrence, Claire; Konopka, Karolina; Rajchert, Joanna

2014-10-01

This paper examines male and female individual differences in situational triggers of aggressive responses (STAR) in three countries as well as cross-cultural sex differences in trait aggression (aggression questionnaire, AQ). Convenience sampling was employed (university students) for the descriptive correlational study (Poland N = 300, 63% female, mean age 21.86, SD = 2.12; UK N = 196, 60% female, mean age 20.48, SD = 3.79; Greece N = 299, 57% female, mean age 20.71, SD = 4.42). The results showed that the STAR scale is an equivalent construct across all three countries. Overall, females were more sensitive to both provocation (SP) and frustration (SF) than males. When controlling for trait aggression, Polish and Greek females scored similarly in SP and higher than UK females. No sex differences in SP or SF were found in the UK sample. Additionally, Polish participants scored the highest in SP. Furthermore, when trait aggression was removed, the Greek participants were most sensitive to frustration, whereas Polish and English participants' SF did not differ. We discuss the results with regard to intercultural differences between investigated countries. © 2014 International Union of Psychological Science.

A glimpse into the genetic basis of symbiosis between Hydrogenophaga and their helper strains in the biodegradation of 4-aminobenzenesulfonate

PubMed Central

Kim, Kangsan; Gan, Han Ming

2017-01-01

We report the whole genome sequences of Hydrogenophaga intermedia S1 and Agrobacterium radiobacter S2, the first reported bacterial co-culture capable of degrading 4-aminobenzenesulfonate (4-ABS), a recalcitrant industrial waste product. To gain insights into the genetic basis for the syntrophic interaction between this symbiotic pair and also another recently reported Hydrogenophaga associated co-culture, Hydrogenophaga sp. PBC and Ralstonia sp. PBA, we performed detailed genetic analysis of these four strains focusing on the metabolic pathways associated with biotin, para-aminobenzoic acid (pABA), and protocatechuate metabolism. Both assembled Hydrogenophaga draft genomes are missing a majority of the genetic components associated in the biosynthetic pathway of pABA and biotin. Interestingly, a fused pABA synthase was found in R. sp PBA but not in A. radiobacter S2. Furthermore, using whole genome data, the taxonomic classification of R. sp. PBA and A. radiobacter S2 (both previously inferred from 16S rRNA gene) was re-investigated, providing new evidence to propose for their re-classification at the genus and species level, respectively PMID:28775791

IAA-producing Penicillium sp. NICS01 triggers plant growth and suppresses Fusarium sp.-induced oxidative stress in sesame (Sesamum indicum L.).

PubMed

Radhakrishnan, Ramalingam; Shim, Kang-Bo; Lee, Byeong-Won; Hwang, Chung-Dong; Pae, Suk-Bok; Park, Chang-Hwan; Kim, Sung-Up; Lee, Choon-Ki; Baek, In-Youl

2013-06-28

Application of rhizospheric fungi is an effective and environmentally friendly method of improving plant growth and controlling many plant diseases. The current study was aimed to identify phytohormone-producing fungi from soil, to understand their roles in sesame plant growth, and to control Fusarium disease. Three predominant fungi (PNF1, PNF2, and PNF3) isolated from the rhizospheric soil of peanut plants were screened for their growth-promoting efficiency on sesame seedlings. Among these isolates, PNF2 significantly increased the shoot length and fresh weight of seedlings compared with controls. Analysis of the fungal culture filtrate showed a higher concentration of indole acetic acid in PNF2 than in the other isolates. PNF2 was identified as Penicillium sp. on the basis of phylogenetic analysis of ITS sequence similarity. The in vitro biocontrol activity of Penicillium sp. against Fusarium sp. was exhibited by a 49% inhibition of mycelial growth in a dual culture bioassay and by hyphal injuries as observed by scanning electron microscopy. In addition, greenhouse experiments revealed that Fusarium inhibited growth in sesame plants by damaging lipid membranes and reducing protein content. Co-cultivation with Penicillium sp. mitigated Fusarium-induced oxidative stress in sesame plants by limiting membrane lipid peroxidation, and by increasing the protein concentration, levels of antioxidants such as total polyphenols, and peroxidase and polyphenoloxidase activities. Thus, our findings suggest that Penicillium sp. is a potent plant growthpromoting fungus that has the ability to ameliorate damage caused by Fusarium infection in sesame cultivation.

The development of a cultural standardized patient examination for a general surgery residency program.

PubMed

Chun, Maria B J; Young, Keane G M; Honda, Andrea F; Belcher, Gary F; Maskarinec, Gregory G

2012-01-01

Cultural competency and cross-cultural care issues in surgery resident education are areas of recognized need. The Accreditation Council for Graduate Medical Education (ACGME) has developed 6 core competencies addressing training to provide high quality care. Of these, cultural training is addressed under 3: patient care, professionalism, and interpersonal and communication skills. Our study sought to develop a measurable tool-a cultural standardized patient (SP) examination-that integrates cross-cultural care issues within the core competencies. All first year surgery residents (PGY-1) were required to participate in the videotaped cultural SP examination as part of the general surgery residency curriculum. Two measures were utilized to assess resident performance. On the same day, we administered a Cross-Cultural Care Survey. The SP examination was assessed by trained surgery teaching faculty using a written checklist that was developed to evaluate residents on all 6 ACGME competencies. Of the 26 eligible participants over 2 years, we were able to analyze the pre- and post-test results for 24 residents. The post-test score of the "attitude toward cross-cultural care" subscale of the Cross-Cultural Care Survey was significantly lower than the pre-test score (p = 0.012; Wilcoxon signed-ranks test). There were significant differences by ethnicity on all 3 subscales of the Cross-Cultural Care Survey (attitude = p < 0.05, knowledge = p < 0.01, skills = p < 0.05) on the pre-test. However, only the knowledge subscale scores remained significantly different between ethnicities on the post-test (p < 0.01). After additional assessment, evaluation, and refinement, our goal is to incorporate cross-cultural health care training as a permanent part of our curriculum. Our hope is that efforts to provide training in cross-cultural healthcare leads to high quality care and positive outcomes for the patient. This will not only enhance our training program, but may also become a useful tool for other surgery residency programs. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Identification of an entomopathogenic bacterium, Serratia sp. ANU101, and its hemolytic activity.

PubMed

Kim, Yonggyun; Kim, Keunseob; Seo, Jiae; Shrestha, Sony; Kim, Hosanna H; Nalini, Madanagopal; Yi, Youngkeun

2009-03-01

Four different bacterial colonies were isolated from an old stock of an entomopathogenic nematode, Steinernema monticolum. They all showed entomopathogenicity to final instar larvae of beet armyworm, Spodoptera exigua, by hemocoelic injection. However, they varied in colony form, susceptibility to antibiotics, and postmortem change of the infected host insects. Biolog microbial identification and 16S rDNA sequence analyses indicate that these are four different species classified into different bacterial genera. owing to high entomopathogenicity and a cadaver color of infected insect host, Serratia sp. was selected as a main symbiotic bacterial species and analyzed for its pathogenicity. Although no virulence of Serratia sp. was detected at oral administration, the bacteria gave significant synergistic pathogenicity to fifth instar S. exigua when it was treated along with a spore-forming entomopathogenic bacterium, Bacillus thuringiensis. The synergistic effect was explained by an immunosuppressive effect of Serratia sp. by its high cytotoxic effect on hemocytes of S. exigua, because Serratia sp. caused septicemia of S. exigua when the bacterial cells were injected into S. exigua hemocoel. The cytotoxic factor(s) was present in the culture medium because the sterilized culture broth possessed high potency in the cytotoxicity, which was specific to granular cells and plasmatocytes, two main immune-associated hemocytes in insects.

Interspecies modulation of bacterial development through iron competition and siderophore piracy

PubMed Central

Traxler, Matthew F.; Seyedsayamdost, Mohammad R.; Clardy, Jon; Kolter, Roberto

2012-01-01

Summary While soil-dwelling actinomycetes are renowned for secreting natural products, little is known about the roles of these molecules in mediating actinomycete interactions. In a previous co-culture screen, we found that one actinomycete, Amycolatopsis sp. AA4, inhibited aerial hyphae formation in adjacent colonies of Streptomyces coelicolor. A siderophore, amychelin, mediated this developmental arrest. Here we present genetic evidence that confirms the role of the amc locus in the production of amychelin and in the inhibition of S. coelicolor development. We further characterize the Amycolatopsis sp. AA4 - S. coelicolor interaction by examining expression of developmental and iron acquisition genes over time in co-culture. Manipulation of iron availability and/or growth near Amycolatopsis sp. AA4 led to alterations in expression of the critical developmental gene bldN, and other key down-stream genes in the S. coelicolor transcriptional cascade. In Amycolatopsis sp. AA4, siderophore genes were down-regulated when grown near S. coelicolor, leading us to find that deferrioxamine E, produced by S. coelicolor, could be readily utilized by Amycolatopsis sp. AA4. Collectively these results suggest that competition for iron via siderophore piracy and species-specific siderophores can alter patterns of gene expression and morphological differentiation during actinomycete interactions. PMID:22931126

Interspecies modulation of bacterial development through iron competition and siderophore piracy.

PubMed

Traxler, Matthew F; Seyedsayamdost, Mohammad R; Clardy, Jon; Kolter, Roberto

2012-11-01

While soil-dwelling actinomycetes are renowned for secreting natural products, little is known about the roles of these molecules in mediating actinomycete interactions. In a previous co-culture screen, we found that one actinomycete, Amycolatopsis sp. AA4, inhibited aerial hyphae formation in adjacent colonies of Streptomyces coelicolor. A siderophore, amychelin, mediated this developmental arrest. Here we present genetic evidence that confirms the role of the amc locus in the production of amychelin and in the inhibition of S. coelicolor development. We further characterize the Amycolatopsis sp. AA4 - S. coelicolor interaction by examining expression of developmental and iron acquisition genes over time in co-culture. Manipulation of iron availability and/or growth near Amycolatopsis sp. AA4 led to alterations in expression of the critical developmental gene bldN, and other key downstream genes in the S. coelicolor transcriptional cascade. In Amycolatopsis sp. AA4, siderophore genes were downregulated when grown near S. coelicolor, leading us to find that deferrioxamine E, produced by S. coelicolor, could be readily utilized by Amycolatopsis sp. AA4. Collectively these results suggest that competition for iron via siderophore piracy and species-specific siderophores can alter patterns of gene expression and morphological differentiation during actinomycete interactions. © 2012 Blackwell Publishing Ltd.

Co-culturing a novel Bacillus strain with Clostridium tyrobutyricum ATCC 25755 to produce butyric acid from sucrose

PubMed Central

2013-01-01

Background Currently, the most promising microorganism used for the bio-production of butyric acid is Clostridium tyrobutyricum ATCC 25755T; however, it is unable to use sucrose as a sole carbon source. Consequently, a newly isolated strain, Bacillus sp. SGP1, that was found to produce a levansucrase enzyme, which hydrolyzes sucrose into fructose and glucose, was used in a co-culture with this strain, permitting C. tyrobutyricum ATCC 25755T to ferment sucrose to butyric acid. Results B. sp. SGP1 alone did not show any butyric acid production and the main metabolite produced was lactic acid. This allowed C. tyrobutyricum ATCC 25755T to utilize the monosaccharides resulting from the activity of levansucrase together with the lactic acid produced by B. sp. SGP1 to generate butyric acid, which was the main fermentative product within the co-culture. Furthermore, the final acetic acid concentration in the co-culture was significantly lower when compared with pure C. tyrobutyricum ATCC 25755T cultures grown on glucose. In fed-batch fermentations, the optimum conditions for the production of butyric acid were around pH 5.50 and a temperature of 37°C. Under these conditions, the final butyrate concentration was 34.2±1.8 g/L with yields of 0.35±0.03 g butyrate/g sucrose and maximum productivity of 0.3±0.04 g/L/h. Conclusions Using this co-culture, sucrose can be utilized as a carbon source for butyric acid production at a relatively high yield. In addition, this co-culture offers also the benefit of a greater selectivity, with butyric acid constituting 92.8% of the acids when the fermentation was terminated. PMID:23452443

Co-culturing a novel Bacillus strain with Clostridium tyrobutyricum ATCC 25755 to produce butyric acid from sucrose.

PubMed

Dwidar, Mohammed; Kim, Seil; Jeon, Byoung Seung; Um, Youngsoon; Mitchell, Robert J; Sang, Byoung-In

2013-03-04

Currently, the most promising microorganism used for the bio-production of butyric acid is Clostridium tyrobutyricum ATCC 25755T; however, it is unable to use sucrose as a sole carbon source. Consequently, a newly isolated strain, Bacillus sp. SGP1, that was found to produce a levansucrase enzyme, which hydrolyzes sucrose into fructose and glucose, was used in a co-culture with this strain, permitting C. tyrobutyricum ATCC 25755T to ferment sucrose to butyric acid. B. sp. SGP1 alone did not show any butyric acid production and the main metabolite produced was lactic acid. This allowed C. tyrobutyricum ATCC 25755T to utilize the monosaccharides resulting from the activity of levansucrase together with the lactic acid produced by B. sp. SGP1 to generate butyric acid, which was the main fermentative product within the co-culture. Furthermore, the final acetic acid concentration in the co-culture was significantly lower when compared with pure C. tyrobutyricum ATCC 25755T cultures grown on glucose. In fed-batch fermentations, the optimum conditions for the production of butyric acid were around pH 5.50 and a temperature of 37°C. Under these conditions, the final butyrate concentration was 34.2±1.8 g/L with yields of 0.35±0.03 g butyrate/g sucrose and maximum productivity of 0.3±0.04 g/L/h. Using this co-culture, sucrose can be utilized as a carbon source for butyric acid production at a relatively high yield. In addition, this co-culture offers also the benefit of a greater selectivity, with butyric acid constituting 92.8% of the acids when the fermentation was terminated.

[Extracellular proteolytic enzymes of Azospirillum brasilensis strain Sp7 and regulation of their activity by a homologous lectin].

PubMed

Chernyshova, M P; Alen'kina, S A; Nikitina, V E; Ignatov, V V

2005-01-01

It was found that Azospirillum brasilensis strain Sp7 is able to produce extracellular proteolytic enzymes. The enzymes were active within a broad range of pH values, with two peaks of activity being located in the acid and alkaline pH areas; required calcium ions; and exhibited substrate specificity with respect to azogelatin. Zymography allowed at least four proteolytic enzymes with molecular weights of 32, 45, 52, and 174 kDa to be detected in A. brasilense Sp7 culture liquid. It was shown that the lectin from A. brasilense Sp7 can inhibit proteolytic enzymes.

Production of gluconic acid using Micrococcus sp.: optimisation of carbon and nitrogen sources.

PubMed

Joshi, V D; Sreekantiah, K R; Manjrekar, S P

1996-01-01

A process for production of gluconic acid from glucose by a Micrococcus sp. is described. More than 400 bacterial cultures isolated from local soil were tested for gluconic acid production. Three isolates, were selected on basis of their ability to produce gluconic acid and high titrable acidity. These were identified as Micrococcus sp. and were named M 27, M 54 and M 81. Nutritional and other parameters for maximum production of gluconic acid by the selected isolates were optimised. It was found that Micrococcus sp. isolate M 27 gave highest yield of 8.19 g gluconic acid from 9 g glucose utilised giving 91% conversion effeciency.

Upregulation and Identification of Antibiotic Activity of a Marine-Derived Streptomyces sp. via Co-Cultures with Human Pathogens.

PubMed

Sung, Anne A; Gromek, Samantha M; Balunas, Marcy J

2017-08-11

Marine natural product drug discovery has begun to play an important role in the treatment of disease, with several recently approved drugs. In addition, numerous microbial natural products have been discovered from members of the order Actinomycetales, particularly in the genus Streptomyces , due to their metabolic diversity for production of biologically active secondary metabolites. However, many secondary metabolites cannot be produced under laboratory conditions because growth conditions in flask culture differ from conditions in the natural environment. Various experimental conditions (e.g., mixed fermentation) have been attempted to increase yields of previously described metabolites, cause production of previously undetected metabolites, and increase antibiotic activity. Adult ascidians-also known as tunicates-are sessile marine invertebrates, making them vulnerable to predation and therefore are hypothesized to use host-associated bacteria that produce biologically active secondary metabolites for chemical defense. A marine-derived Streptomyces sp. strain PTY087I2 was isolated from a Panamanian tunicate and subsequently co-cultured with human pathogens including Bacillus subtilis , methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa , followed by extraction. Co-culture of Streptomyces sp. PTY087I2 with each of these human pathogens resulted in increased production of three antibiotics: granaticin, granatomycin D, and dihydrogranaticin B, as well as several analogues seen via molecular networking. In addition, co-cultures resulted in strongly enhanced biological activity against the Gram positive human pathogens used in these experiments. Expanded utilization of co-culture experiments to allow for competitive interactions may enhance metabolite production and further our understanding of these microbial interactions.

Diversity of bacteria producing pigmented colonies in aerosol, snow and soil samples from remote glacial areas (Antarctica, Alps and Andes)

NASA Astrophysics Data System (ADS)

González-Toril, E.; Amils, R.; Delmas, R. J.; Petit, J.-R.; Komárek, J.; Elster, J.

2008-04-01

Four different communities and one culture of pigmented microbial assemblages were obtained by incubation in mineral medium of samples collected from high elevation snow in the Alps (Mt. Blanc area) and the Andes (Nevado Illimani summit, Bolivia), from Antarctic aerosol (French station Dumont d'Urville) and a maritime Antarctic soil (King George Island, South Shetlands, Uruguay Station Artigas). Molecular analysis of more than 200 16S rRNA gene sequences showed that all cultured cells belong to the Bacteria domain. The phylogenetic comparison with the currently available rDNA database allowed the identification of sequences belonging to Proteobacteria (Alpha-, Beta- and Gamma-proteobacteria), Actinobacteria and Bacteroidetes phyla. The Andes snow culture was the richest in bacterial diversity (eight microorganisms identified) and the maritime Antarctic soil the poorest (only one). Snow samples from Col du midi (Alps) and the Andes shared the highest number of identified microorganisms (Agrobacterium, Limnobacter, Aquiflexus and two uncultured Alphaproteobacteria clones). These two sampling sites also shared four sequences with the Antarctic aerosol sample (Limnobacter, Pseudonocardia and an uncultured Alphaproteobacteria clone). The only microorganism identified in the maritime Antarctica soil (Brevundimonas sp.) was also detected in the Antarctic aerosol. The two snow samples from the Alps only shared one common microorganism. Most of the identified microorganisms have been detected previously in cold environments (Dietzia kujamenisi, Pseudonocardia Antarctica, Hydrogenophaga palleronii and Brebundimonas sp.), marine sediments (Aquiflexus balticus, Pseudomonas pseudoalkaligenes, Pseudomonas sp. and one uncultured Alphaproteobacteria), and soils and rocks (Pseudonocardia sp., Agrobactrium sp., Limnobacter sp. and two uncultured Alphaproteobacetria clones). Air current dispersal is the best model to explain the presence of very specific microorganisms, like those used in this work, in very distant environments. In addition these microorganisms have to be resistant to extreme conditions and able to grow in oligotrophic environments. Considering the habitats in which they have been identified, the presence of pigments must be related with their ability to resist high doses of radiation.

Isolation and characterization of a novel Helicobacter species, Helicobacter jaachi sp. nov., from common marmosets (Callithrix jaachus)

PubMed Central

Shen, Zeli; Feng, Yan; Sheh, Alexander; Everitt, Jeffrey; Bertram, Frederick; Paster, Bruce J.

2015-01-01

Purpose-bred common marmosets from domestic sources housed in a US research facility, and used in multiple drug discovery programmes, were noted to have a high incidence of spontaneous inflammatory bowel disease and sporadic cholecystitis and cholangiohepatitis. Inflammatory infiltrates increased in incidence and severity with age. Because Helicobacter spp. have been linked to gastrointestinal diseases, samples from the gastrointestinal tracts of 39 marmosets were screened for Helicobacter spp. by culture and PCR. Helicobacter spp. were frequently detected in marmosets; 28.2 % of the marmosets were positive for a proposed novel species, Helicobacter jaachi sp. nov., by culture, and 48.7 % were positive by Helicobacter genus-specific PCR. Seventeen strains of Helicobacter sp. from 11 marmosets were cultured from various gastrointestinal sites. Older animals (age 6–11 years) had a higher helicobacter prevalence rate (57.1 %) compared with younger animals (age 3–5 years), which had a 27.2 % prevalence rate. Cells of H. jaachi sp. nov. were catalase, urease and oxidase positive and had fusiform morphology, with periplasmic fibres and multiple bipolar, sheathed flagella. All isolates had similar 16S and 23S rRNA sequences, which clustered as representatives of a novel Helicobacter species closely related to ‘Helicobacter sanguini’ (97 %), a species isolated from cotton-top tamarins and ‘Helicobacter callitrichis’ (96 %) isolated previously from the faeces of common marmosets. The whole genome sequence of one of the liver isolates, H. jaachi sp. nov. MIT 09-6949T, had a 1.9 Mb genome length with a 41 mol% DNA G+C content. The type strain of Helicobacter jaachi sp. nov., MIT 09-6949T, has been deposited in the BCCM/LMG Bacteria Collection as LMG 28613T. These findings add to the increasing number of animal species with gastrointestinal disease in which novel enterohepatic Helicobacter spp. have been isolated. PMID:26297446

Detection and identification of intestinal pathogenic bacteria by hybridization to oligonucleotide microarrays

PubMed Central

Jin, Lian-Qun; Li, Jun-Wen; Wang, Sheng-Qi; Chao, Fu-Huan; Wang, Xin-Wei; Yuan, Zheng-Quan

2005-01-01

AIM: To detect the common intestinal pathogenic bacteria quickly and accurately. METHODS: A rapid (<3 h) experimental procedure was set up based upon the gene chip technology. Target genes were amplified and hybridized by oligonucleotide microarrays. RESULTS: One hundred and seventy strains of bacteria in pure culture belonging to 11 genera were successfully discriminated under comparatively same conditions, and a series of specific hybridization maps corresponding to each kind of bacteria were obtained. When this method was applied to 26 divided cultures, 25 (96.2%) were identified. CONCLUSION: Salmonella sp., Escherichia coli, Shigella sp., Listeria monocytogenes, Vibrio parahaemolyticus, Staphylococcus aureus, Proteus sp., Bacillus cereus, Vibrio cholerae, Enterococcus faecalis, Yersinia enterocolitica, and Campylobacter jejuni can be detected and identified by our microarrays. The accuracy, range, and discrimination power of this assay can be continually improved by adding further oligonucleotides to the arrays without any significant increase of complexity or cost. PMID:16437687

Occurrence of the haemocyte parasite Bonamia sp. in flat oysters Ostrea puelchana farmed in San Antonio Bay (Argentina).

PubMed

Kroeck, Marina A; Montes, Jaime

2005-02-28

Culture of native flat oysters Ostrea puelchana d'Orbigny in San Antonio Bay (San Matías Gulf, Argentina) began in 1995. After elevated mortality (33%) occurred in September 1996, 18 mo after immersion, histopathological analysis and evaluation of parasitic prevalence was carried out. In October 1997, after 31 mo of cultivation, cumulative mortality was 80%, and in December of the same year, when individuals reached marketable size, mortality was 95% and culture was discontinued. The present study describes the haemocytic parasitism that affected O. puelchana, and suggests that a Bonamia sp. was the etiological agent. This parasite should be considered as a different species from Bonamia sp. detected in Australia and New Zealand until more studies are made to determine the correct taxonomy. This work constitutes the first record of this haemocyte parasite in flat oysters from the Argentinean coast.

Improved production of an enzyme that hydrolyses raw yam starch by Penicillium sp. S-22 using fed-batch fermentation.

PubMed

Sun, Hai-Yan; Ge, Xiang-Yang; Zhang, Wei-Guo

2006-11-01

A newly isolated strain, Penicillium sp. S-22, was used to produce an enzyme that hydrolyses raw yam starch [raw yam starch digesting enzyme (RYSDE)]. The enzyme activity and overall enzyme productivity were respectively 16 U/ml and 0.19 U/ml h in the batch culture. The enzyme activity increased to 85 U/ml by feeding of partially hydrolyzed raw yam starch. When a mixture containing partially hydrolyzed raw yam starch and peptone was fed by a pH-stat strategy, the enzyme activity reached 366 U/ml, 23-fold of that obtained in the batch culture, and the overall productivity reached 3.4 U/ml h, which was 18-fold of that in the batch culture.

Myxozoan pathogens in cultured Malaysian fishes. II. Myxozoan infections of redtail catfish Hemibagrus nemurus in freshwater cage cultures.

PubMed

Molnár, K; Székely, C; Mohamed, K; Shaharom-Harrison, F

2006-03-02

Cage-cultured Asian redtail catfish Hemibagrus nemurus (Valenciennes, 1840), a popular food fish in Southeast Asia, proved to be infected by 3 myxozoan species. All the 3 species belonged to the genus Henneguya: 2 were identified as H. mystusia Sarkar, 1985 and H. hemibagri Tchang et Ma, 1993, while the other was described as H. basifilamentalis sp. n. All plasmodia were found in the gills and were characterised by a specific site selection. H. mystusia formed plasmodia in the multi-layered epithelium between the gill lamellae and in the non-lamellar edge of the gill filaments, while H. hemibagri developed in the capillary network of the lamellae. H. basifilamentalis sp. n. had large oval plasmodia located deep among the filaments just above the gill arch.

Detection of bioactive exometabolites produced by the filamentous marine cyanobacterium Geitlerinema sp.

PubMed

Caicedo, Nelson H; Kumirska, Jolanta; Neumann, Jennifer; Stolte, Stefan; Thöming, Jorg

2012-08-01

Marine cyanobacteria are noted for their ability to excrete metabolites with biotic properties. This paper focuses on such exometabolites obtained from the culture of the marine filamentous cyanobacterium Geitlerinema sp. strain, their purification and subsequent analyses. By this means the recoveries of the active compounds, a prerequisite for properly determining their concentration, are quantified here for the first time. We demonstrate a new procedure using Amberlite XAD-1180 resin in combination with the eluent isopropanol for extraction of the culture media and gas chromatography as simplified chemical analysis. This procedure reduced necessary bacteria cultivation time (from 150 to 21 days) at low volumes of culture media (300 mL) required for identification of two selected bioactive compounds: 4,4'-dihydroxybiphenyl and harmane.

Stimulation of synthesis and release of brain-derived neurotropic factor from intestinal smooth muscle cells by substance P and pituitary adenylate cyclase-activating peptide.

PubMed

Al-Qudah, M; Alkahtani, R; Akbarali, H I; Murthy, K S; Grider, J R

2015-08-01

Brain-derived neurotrophic factor (BDNF) is a neurotrophin present in the intestine where it participates in survival and growth of enteric neurons, augmentation of enteric circuits, and stimulation of intestinal peristalsis and propulsion. Previous studies largely focused on the role of neural and mucosal BDNF. The expression and release of BDNF from intestinal smooth muscle and the interaction with enteric neuropeptides has not been studied in gut. The expression and secretion of BDNF from smooth muscle cultured from the rabbit intestinal longitudinal muscle layer in response to substance P (SP) and pituitary adenylate cyclase-activating peptide (PACAP) was measured by western blot and enzyme-linked immunosorbent assay. BDNF mRNA was measured by reverse-transcription polymerase chain reaction. The expression of BNDF protein and mRNA was greater in smooth muscle cells (SMCs) from the longitudinal muscle than from circular muscle layer. PACAP and SP increased the expression of BDNF protein and mRNA in cultured longitudinal SMCs. PACAP and SP also stimulated the secretion of BDNF from cultured longitudinal SMCs. Chelation of intracellular calcium with BAPTA (1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) prevented SP-induced increase in BDNF mRNA and protein expression and SP-induced secretion of BDNF. Neuropeptides known to be present in enteric neurons innervating the longitudinal layer increase the expression of BDNF mRNA and protein in SMCs and stimulate the release of BDNF. Considering the ability of BDNF to enhance smooth muscle contraction, this autocrine loop may partially explain the characteristic hypercontractility of longitudinal muscle in inflammatory bowel disease. © 2015 John Wiley & Sons Ltd.

Nerve growth factor-enhanced airway responsiveness involves substance P in ferret intrinsic airway neurons.

PubMed

Wu, Z-X; Dey, R D

2006-07-01

Nerve growth factor (NGF), a member of the neurotrophin family, enhances synthesis of neuropeptides in sensory and sympathetic neurons. The aim of this study was to examine the effect of NGF on airway responsiveness and determine whether these effects are mediated through synthesis and release of substance P (SP) from the intrinsic airway neurons. Ferrets were instilled intratracheally with NGF or saline. Tracheal smooth muscle contractility to methacholine and electrical field stimulation (EFS) was assessed in vitro. Contractions of isolated tracheal smooth muscle to EFS at 10 and 30 Hz were significantly increased in the NGF treatment group (10 Hz: 33.57 +/- 2.44%; 30 Hz: 40.12 +/- 2.78%) compared with the control group (10 Hz: 27.24 +/- 2.14%; 30 Hz: 33.33 +/- 2.31%). However, constrictive response to cholinergic agonist was not significantly altered between the NGF treatment group and the control group. The NGF-induced modulation of airway smooth muscle to EFS was maintained in tracheal segments cultured for 24 h, a procedure that causes a significant anatomic and functional loss of SP-containing sensory fibers while maintaining viability of intrinsic airway neurons. The number of SP-containing neurons in longitudinal trunk and superficial muscular plexus and SP nerve fiber density in tracheal smooth muscle all increased significantly in cultured trachea treated with NGF. Pretreatment with CP-99994, an antagonist of neurokinin 1 receptor, attenuated the NGF-induced increased contraction to EFS in cultured segments but had no effect in saline controls. These results show that the NGF-enhanced airway smooth muscle contractile responses to EFS are mediated by the actions of SP released from intrinsic airway neurons.

Culture and molecular identification of fungal contaminants in edible bird nests.

PubMed

Chen, Jennifer Xiao Jing; Wong, Shew Fung; Lim, Patricia Kim Chooi; Mak, Joon Wah

2015-01-01

Widespread food poisoning due to microbial contamination has been a major concern for the food industry, consumers and governing authorities. This study is designed to determine the levels of fungal contamination in edible bird nests (EBNs) using culture and molecular techniques. Raw EBNs were collected from five house farms, and commercial EBNs were purchased from five Chinese traditional medicine shops (companies A-E) in Peninsular Malaysia. The fungal contents in the raw and commercial EBNs, and boiled and unboiled EBNs were determined. Culturable fungi were isolated and identified. In this study, the use of these methods revealed that all EBNs had fungal colony-forming units (CFUs) that exceeded the limit set by Standards and Industrial Research Institute of Malaysia (SIRIM) for yeast and moulds in EBNs. There was a significant difference (p < 0.05) in the number of types of fungi isolated from raw and commercial EBNs, but no significant difference in the reduction of the number of types of fungi after boiling the EBNs (p > 0.05). The types of fungi isolated from the unboiled raw EBNs were mainly soil, plant and environmental fungi, while the types of fungi isolated from the boiled raw EBNs, unboiled and boiled commercial EBNs were mainly environmental fungi. Aspergillus sp., Candida sp., Cladosporium sp., Neurospora sp. and Penicillum sp. were the most common fungi isolated from the unboiled and boiled raw and commercial EBNs. Some of these fungi are mycotoxin producers and cause opportunistic infections in humans. Further studies to determine the mycotoxin levels and methods to prevent or remove these contaminations from EBNs for safe consumption are necessary. The establishment and implementation of stringent regulations for the standards of EBNs should be regularly updated and monitored to improve the quality of the EBNs and consumer safety.

Identification of Fungal Communities Associated with the Biodeterioration of Waterlogged Archeological Wood in a Han Dynasty Tomb in China

PubMed Central

Liu, Zijun; Wang, Yu; Pan, Xiaoxuan; Ge, Qinya; Ma, Qinglin; Li, Qiang; Fu, Tongtong; Hu, Cuiting; Zhu, Xudong; Pan, Jiao

2017-01-01

The Mausoleum of the Dingtao King (termed ‘M2’) is a large-scale huangchang ticou tomb that dates to the Western Han Dynasty (206 B.C.–25 A.D.). It is the highest-ranking Han Dynasty tomb discovered to date. However, biodeterioration on the surface of the tomb M2 is causing severe damage to its wooden materials. The aim of the present study was to give insight into the fungal communities colonized the wooden tomb. For this purpose, seven samples were collected from different sections of the tomb M2 which exhibited obvious biodeterioration in the form of white spots. Microbial structures associated with the white spots were observed with scanning electron microscopy. Fungal community structures were assessed for seven samples via a combination of high-throughput sequencing and culture-dependent techniques. Sequencing analyses identified 114 total genera that belonged to five fungal phyla. Hypochnicium was the most abundant genus across all samples and accounted for 98.61–99.45% of the total community composition. Further, Hypochnicium sp. and Mortierella sp. cultures were successfully isolated from the tomb samples, and were distinguished as Hypochnicium sp. WY-DT1 and Mortierella sp. NK-DT1, respectively. Cultivation-dependent experiments indicated that the dominant member, Hypochnicium sp. WY- DT1, could grow at low temperatures and significantly degraded cellulose and lignin. Thus, our results taken together suggest that this fungal strain must be regarded as a serious threat to the preservation of the wooden tomb M2. The results reported here are useful for informing future contamination mitigation efforts for the tomb M2 as well as other similar cultural artifacts. PMID:28890715

Enhancement of Palmarumycin C12 and C13 Production by the Endophytic Fungus Berkleasmium sp. Dzf12 in an Aqueous-Organic Solvent System.

PubMed

Mou, Yan; Xu, Dan; Mao, Ziling; Dong, Xuejiao; Lin, Fengke; Wang, Ali; Lai, Daowan; Zhou, Ligang; Xie, Bingyan

2015-11-12

The endophytic fungus Berkleasmium sp. Dzf12, isolated from Dioscorea zingiberensis, was found to produce palmarumycins C12 and C13 which possess a great variety of biological activities. Seven biocompatible water-immiscible organic solvents including n-dodecane, n-hexadecane, 1-hexadecene, liquid paraffin, dibutyl phthalate, butyl oleate and oleic acid were evaluated to improve palmarumycins C12 and C13 production in suspension culture of Berkleasmium sp. Dzf12. Among the chosen solvents both butyl oleate and liquid paraffin were the most effective to improve palmarumycins C12 and C13 production. The addition of dibutyl phthalate, butyl oleate and oleic acid to the cultures of Berkleasmium sp. Dzf12 significantly enhanced palmarumycin C12 production by adsorbing palmarumycin C12 into the organic phase. When butyl oleate was fed at 5% (v/v) in medium at the beginning of fermentation (day 0), the highest palmarumycin C12 yield (191.6 mg/L) was achieved, about a 34.87-fold increase in comparison with the control (5.3 mg/L). n-Dodecane, 1-hexadecene and liquid paraffin had a great influence on the production of palmarumycin C13. When liquid paraffin was added at 10% (v/v) in medium on day 3 of fermentation, the palmarumycin C13 yield reached a maximum value (134.1 mg/L), which was 4.35-fold that of the control (30.8 mg/L). Application of the aqueous-organic solvent system should be a simple and efficient process strategy for enhancing palmarumycin C12 and C13 production in liquid cultures of the endophytic fungus Berkleasmium sp. Dzf12.

Far from superficial: microbial diversity associated with the skin and mucus of fish

USGS Publications Warehouse

Cipriano, Rocco C.; Dove, Alistair; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

2011-01-01

During horizontal or water-borne infection involving an obligate pathogen (e.g. – Aeromonas salmonicida, cause of furunculosis), the pathogen interacted with and influenced the microbial diversity of the dermal mucus of fish. Prior to infection, the prevalent bacterial flora cultured from juvenile Atlantic salmon (Salmo salar) included Pseudomonas fluorescens, Comomonas terrigenia, Acinetobacter sp., Moraxella sp., Pseudomonas dimunita, Alcaligenes denitrificans, Pseudomonas pseudoalcaligenes, and Pseudomonas alcaligenes, Serratia liquefaciens, Aeromonas hydrophila, other motile Aeromonas spp., and Corynebacterium aquaticum. After A. salmonicida was initially detected in this population as an external mucus infection, Acinetobacter sp., Moraxella sp., C. terrigenia, P. fluorescens, and P. dimunita, Staphylococcus sp., and A. hydrophila, were also present in appreciable numbers. Within several weeks, however, the A. salmonicida infection amplified and composed 78% of the total flora in the mucus. Only P. dimunita (4%). P. fluorescens (2%), and C. terrigenia (1%) were cultured at that time and more than a third of these fish showed evidence of a systemic A. salmonicida infection within their kidneys. Eight weeks after oral oxytetracycline treatments, A. salmonicida was no longer isolated from the mucus or kidneys of any fish and glucose inert or other oxidative microbes (e.g., P. fluorescens, C. terrigenia, Acinetobacter sp., Moraxella sp.) were beginning to repopulate the external surface of the salmon in increasing frequency. Still present and composing fairly large percentages of the total flora were A. hydrophila, as well as Enterobacter sp., and P. putrefaciens. A normal microbial diversity was re-established as the fish recovered. In another investigation, reduced biological diversity was noted in the dermal mucus among smallmouth bass that were sampled from the Jackson River (Covington, VA). In these fish, A. hydrophila and P. putrefaciens were the two predominant microorganisms composing 49.5% and 31.2% of the total bacterial flora, despite the absence of systemic infection or any other clinical signs of disease. In another instance, P. fluorescens was the sole bacterium associated with the surface of Atlantic salmon eggs regardless of their viability at the eyed stage of development. Collectively, these results indicate that the kinetics and distributions of the surface bacterial flora on aquatic organisms is affected by numerous factors including pathogen invasion, environmental conditions, and fish culture practices.

Characterization of Fe (III)-reducing enrichment culture and isolation of Fe (III)-reducing bacterium Enterobacter sp. L6 from marine sediment.

PubMed

Liu, Hongyan; Wang, Hongyu

2016-07-01

To enrich the Fe (III)-reducing bacteria, sludge from marine sediment was inoculated into the medium using Fe (OH)3 as the sole electron acceptor. Efficiency of Fe (III) reduction and composition of Fe (III)-reducing enrichment culture were analyzed. The results indicated that the Fe (III)-reducing enrichment culture with the dominant bacteria relating to Clostridium and Enterobacter sp. had high Fe (III) reduction of (2.73 ± 0.13) mmol/L-Fe (II). A new Fe (III)-reducing bacterium was isolated from the Fe (III)-reducing enrichment culture and identified as Enterobacter sp. L6 by 16S rRNA gene sequence analysis. The Fe (III)-reducing ability of strain L6 under different culture conditions was investigated. The results indicated that strain L6 had high Fe (III)-reducing activity using glucose and pyruvate as carbon sources. Strain L6 could reduce Fe (III) at the range of NaCl concentrations tested and had the highest Fe (III) reduction of (4.63 ± 0.27) mmol/L Fe (II) at the NaCl concentration of 4 g/L. This strain L6 could reduce Fe (III) with unique properties in adaptability to salt variation, which indicated that it can be used as a model organism to study Fe (III)-reducing activity isolated from marine environment. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Quantification of viable bacterial starter cultures of Virgibacillus sp. and Tetragenococcus halophilus in fish sauce fermentation by real-time quantitative PCR.

PubMed

Udomsil, Natteewan; Chen, Shu; Rodtong, Sureelak; Yongsawatdigul, Jirawat

2016-08-01

Real-time quantitative polymerase chain reaction (qPCR) methods were developed for the quantification of Virgibacillus sp. SK37 and Tetragenococcus halophilus MS33, which were added as starter cultures in fish sauce fermentation. The PCR assays were coupled with propidium monoazide (PMA) treatment of samples to selectively quantify viable cells and integrated with exogenous recombinant Escherichia coli cells to control variabilities in analysis procedures. The qPCR methods showed species-specificity for both Virgibacillus halodenitrificans and T. halophilus as evaluated using 6 reference strains and 28 strains of bacteria isolated from fish sauce fermentation. The qPCR efficiencies were 101.1% for V. halodenitrificans and 90.2% for T. halophilus. The quantification limits of the assays were 10(3) CFU/mL and 10(2) CFU/mL in fish sauce samples with linear correlations over 4 Logs for V. halodenitrificans and T. halophilus, respectively. The matrix effect was not observed when evaluated using fish sauce samples fermented for 1-6 months. The developed PMA-qPCR methods were successfully applied to monitor changes of Virgibacillus sp. SK37 and T. halophilus MS33 in a mackerel fish sauce fermentation model where culture-dependent techniques failed to quantify the starter cultures. The results demonstrated the usability of the methods as practical tools for monitoring the starter cultures in fish sauce fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Test characteristics of milk amyloid A ELISA, somatic cell count, and bacteriological culture for detection of intramammary pathogens that cause subclinical mastitis.

PubMed

Jaeger, S; Virchow, F; Torgerson, P R; Bischoff, M; Biner, B; Hartnack, S; Rüegg, S R

2017-09-01

Bovine mastitis is an important disease in the dairy industry, causing economic losses as a result of withheld milk and treatment costs. Several studies have suggested milk amyloid A (MAA) as a promising biomarker in the diagnosis of mastitis. In the absence of a gold standard for diagnosis of subclinical mastitis, we estimated the diagnostic test accuracy of a commercial MAA-ELISA, somatic cell count (SCC), and bacteriological culture using Bayesian latent class modeling. We divided intramammary infections into 2 classes: those caused by major pathogens (e.g., Escherichia coli, Staphylococcus aureus, streptococci, and lacto-/enterococci) and those caused by all pathogens (major pathogens plus Corynebacterium bovis, coagulase-negative staphylococci, Bacillus spp., Streptomyces spp.). We applied the 3 diagnostic tests to all samples. Of 433 composite milk samples included in this study, 275 (63.5%) contained at least 1 colony of any bacterial species; of those, 56 contained major pathogens and 219 contained minor pathogens. The remaining 158 samples (36.5%) were sterile. We determined 2 different thresholds for the MAA-ELISA using Bayesian latent class modeling: 3.9 µg/mL to detect mastitis caused by major pathogens and 1.6 µg/mL to detect mastitis caused by all pathogens. The optimal SCC threshold for identification of subclinical mastitis was 150,000 cells/mL; this threshold led to higher specificity (Sp) than 100,000 cells/mL. Test accuracy for major-pathogen intramammary infections was as follows: SCC, sensitivity (Se) 92.6% and Sp 72.9%; MAA-ELISA, Se 81.4% and Sp 93.4%; bacteriological culture, Se 23.8% and Sp 95.2%. Test accuracy for all-pathogen intramammary infections was as follows: SCC, sensitivity 90.3% and Sp 71.8%; MAA-ELISA, Se 88.0% and Sp 65.2%; bacteriological culture, Se 83.8% and Sp 54.8%. We suggest the use of SCC and MAA-ELISA as a combined screening procedure for situations such as a Staphylococcus aureus control program. With Bayesian latent class analysis, we were able to identify a more differentiated use of the 3 diagnostic tools. The MAA-ELISA is a valuable addition to existing tools for the diagnosis of subclinical mastitis. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Cell Homogeneity Indispensable for Regenerative Medicine by Cultured Human Corneal Endothelial Cells.

PubMed

Hamuro, Junji; Toda, Munetoyo; Asada, Kazuko; Hiraga, Asako; Schlötzer-Schrehardt, Ursula; Montoya, Monty; Sotozono, Chie; Ueno, Morio; Kinoshita, Shigeru

2016-09-01

To identify the subpopulation (SP) among heterogeneous cultured human corneal endothelial cells (cHCECs) devoid of cell-state transition applicable for cell-based therapy. Subpopulation presence in cHCECs was confirmed via surface CD-marker expression level by flow cytometry. CD markers effective for distinguishing distinct SPs were selected by analyzing those on established cHCECs with a small cell area and high cell density. Contrasting features among three typical cHCEC SPs was confirmed by PCR array for extracellular matrix (ECM). Combined analysis of CD markers was performed to identify the SP (effector cells) applicable for therapy. ZO-1 and Na+/K+ ATPase, CD200, and HLA expression were compared among heterogeneous SPs. Flow cytometry analysis identified the effector cell expressing CD166+CD105-CD44-∼+/-CD26-CD24-, but CD200-, and the presence of other SPs with CD166+ CD105-CD44+++ (CD26 and CD24, either + or -) was confirmed. PCR array revealed three distinct ECM expression profiles. Some SPs expressed ZO-1 and Na+/K+ ATPase at comparable levels with effector cells, while only one SP expressed CD200, but not on effector cells. Human leukocyte antigen expression was most reduced in the effector SP. The proportion of effector cells (E-ratio) inversely paralleled donor age and decreased during prolonged culture passages. The presence of Rho-associated protein kinase (ROCK) inhibitor increased the E-ratio in cHCECs. The average area of effector cells was approximately 200∼220 μm2, and the density of cHCECs exceeded 2500 cells/mm2. A specified cultured effector cell population sharing the surface phenotypes with mature HCECs in corneal tissues may serve as an alternative to donor corneas for the treatment of corneal endothelial dysfunction.

Regulatory CD8{sup +} T cells induced by exposure to all-trans retinoic acid and TGF-{beta} suppress autoimmune diabetes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kishi, Minoru; Yasuda, Hisafumi, E-mail: yasuda@med.kobe-u.ac.jp; Abe, Yasuhisa

Antigen-specific regulatory CD4{sup +} T cells have been described but there are few reports on regulatory CD8{sup +} T cells. We generated islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)-specific regulatory CD8{sup +} T cells from 8.3-NOD transgenic mice. CD8{sup +} T cells from 8.3-NOD splenocytes were cultured with IGRP, splenic dendritic cells (SpDCs), TGF-{beta}, and all-trans retinoic acid (ATRA) for 5 days. CD8{sup +} T cells cultured with either IGRP alone or IGRP and SpDCs in the absence of TGF-{beta} and ATRA had low Foxp3{sup +} expression (1.7 {+-} 0.9% and 3.2 {+-} 4.5%, respectively). In contrast, CD8{sup +} T cellsmore » induced by exposure to IGRP, SpDCs, TGF-{beta}, and ATRA showed the highest expression of Foxp3{sup +} in IGRP-reactive CD8{sup +} T cells (36.1 {+-} 10.6%), which was approximately 40-fold increase compared with that before induction culture. CD25 expression on CD8{sup +} T cells cultured with IGRP, SpDCs, TGF-{beta}, and ATRA was only 7.42%, whereas CD103 expression was greater than 90%. These CD8{sup +} T cells suppressed the proliferation of diabetogenic CD8{sup +} T cells from 8.3-NOD splenocytes in vitro and completely prevented diabetes onset in NOD-scid mice in cotransfer experiments with diabetogenic splenocytes from NOD mice in vivo. Here we show that exposure to ATRA and TGF-{beta} induces CD8{sup +}Foxp3{sup +} T cells ex vivo, which suppress diabetogenic T cells in vitro and in vivo.« less

Coexisting bacterial populations responsible for multiphasic mineralization kinetics in soil. [Janthinobacterium sp. Rhodococcus sp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, S.K.; Gier, M.J.

1990-09-01

Experiments were conducted to study populations of indigenous microorganisms capable of mineralizing 2,4-dinitrophenol (DNP) in two soils. Previous kinetic analyses indicated the presence of two coexisting populations of DNP-mineralizing microorganisms in a forest soil (soil 1). Studies in which eucaryotic and procaryotic inhibitors were added to this soil indicated that both populations were bacterial. Most-probable-number counts with media containing different concentrations of DNP indicated that more bacteria could mineralize low concentrations of DNP than could metabolize high concentrations of it. Enrichments with varying concentrations of DNP and various combinations of inhibitors consistently resulted in the isolation of the same twomore » species of bacteria from soil 1. This soil contained a large number and variety of fungi, but no fungi capable of mineralizing DNP were isolated. The two bacterial isolates were identified as a Janthinobacterium sp. and a Rhodococcus sp. The Janthinobacterium sp. had a low {mu}{sub max} and a low K{sub m} for DNP mineralization, whereas the Rhodococcus sp. had much higher values for both parameters. These differences between the two species of bacteria were similar to differences seen when soil was incubated with different concentrations of DNP. Values for {mu}{sub max} from soil incubations were similar to {mu}{sub max} values obtained in pure culture studies. In contrast, K{sub s} and K{sub m} values showed greater variation between soil and pure culture studies.« less

Enhanced saturated fatty acids accumulation in cultures of newly-isolated strains of Schizochytrium sp. and Thraustochytriidae sp. for large-scale biodiesel production.

PubMed

Wang, Qiuzhen; Sen, Biswarup; Liu, Xianhua; He, Yaodong; Xie, Yunxuan; Wang, Guangyi

2018-08-01

Heterotrophic marine protists (Thraustochytrids) have received increasingly global attention as a renewable, sustainable and alternative source of biodiesel because of their high ability of saturated fatty acids (SFAs) accumulation. Yet, the influence of extrinsic factors (nutrients and environmental conditions) on thraustochytrid culture and optimal conditions for high SFAs production are poorly described. In the present study, two different thraustochytrid strains, Schizochytrium sp. PKU#Mn4 and Thraustochytriidae sp. PKU#Mn16 were studied for their growth and SFAs production profiles under various conditions (carbon, nitrogen, temperature, pH, KH 2 PO 4 , salinity, and agitation speed). Of the culture conditions, substrates (C and N) source and conc., temperature, and agitation speed significantly influenced the cell growth and SFAs production of both strains. Although both the strains were capable of growth and SFAs production in the broad range of culture conditions, their physiological responses to KH 2 PO 4 , pH, and salinity were dissimilar. Under their optimal batch culture conditions, peak SFAs productions of 3.3g/L and 2.2g/L with 62% and 49% SFAs contents (relative to total fatty acids) were achieved, respectively. The results of 5-L fed-batch fermentation under optimal conditions showed a nearly 4.5-fold increase in SFAs production (i.e., 7.5g/L) by both strains compared to unoptimized conditions. Of the two strains, the quality of biodiesel produced from the fatty acids of PKU#Mn4 met the biodiesel standard defined by ASTM6751. This study, to the knowledge of the authors, is the first comprehensive report of optimal fermentation conditions demonstrating enhanced SFAs production by strains belonging to two different thraustochytrid genera and provides the basis for large-scale biodiesel production. Copyright © 2018. Published by Elsevier B.V.