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Sample records for actinomycete strain designated

  1. Strain improvement in actinomycetes in the postgenomic era.

    PubMed

    Baltz, Richard H

    2011-06-01

    With the recent advances in DNA sequencing technologies, it is now feasible to sequence multiple actinomycete genomes rapidly and inexpensively. An important observation that emerged from early Streptomyces genome sequencing projects was that each strain contains genes that encode 20 or more potential secondary metabolites, only a fraction of which are expressed during fermentation. More recently, this observation has been extended to many other actinomycetes with large genomes. The discovery of a wealth of orphan or cryptic secondary metabolite biosynthetic gene clusters has suggested that sequencing large numbers of actinomycete genomes may provide the starting materials for a productive new approach to discover novel secondary metabolites. The key issue for this approach to be successful is to find ways to turn on or turn up the expression of cryptic or poorly expressed pathways to provide material for structure elucidation and biological testing. In this review, I discuss several genetic approaches that are potentially applicable to many actinomycetes for this application.

  2. Isolation and in vitro selection of actinomycetes strains as potential probiotics for aquaculture

    PubMed Central

    Bernal, Milagro García; Campa-Córdova, Ángel Isidro; Saucedo, Pedro Enrique; González, Marlen Casanova; Marrero, Ricardo Medina; Mazón-Suástegui, José Manuel

    2015-01-01

    Aim: This study was designed to describe a series of in vitro tests that may aid the discovery of probiotic strains from actinomycetes. Materials and Methods: Actinomycetes were isolated from marine sediments using four different isolation media, followed by antimicrobial activity and toxicity assessment by the agar diffusion method and the hemolysis of human blood cells, respectively. Extracellular enzymatic production was monitored by the hydrolysis of proteins, lipids and carbohydrates. Tolerance to different pH values and salt concentrations was also determined, followed by hydrophobicity analysis and genetic identification of the most promising strains. Results: Five out of 31 isolated strains showed antimicrobial activity against three Vibrio species. Three non-hemolytic strains (N7, RL8 and V4) among these active isolates yielded positive results in hydrophobicity tests and exhibited good growth at salt concentrations ranging from 0% to 10%, except strain RL8, which required a salt concentration >0.6%. Although these strains did not grow at pH<3, they showed different enzymatic activities. Phylogenetic analysis revealed that strains N7 and V4 have more than 99% identity with several Streptomyces species, whereas the closest matches to strain RL8 are Streptomyces panacagri and Streptomyces flocculus, with 98% and 98.2% similarity, respectively. Conclusion: Three actinomycetes strains showing probiotic-like properties were discovered using several in vitro tests that can be easily implemented in different institutions around the world. PMID:27047067

  3. Biology of Frankia strains, actinomycete symbionts of actinorhizal plants.

    PubMed Central

    Benson, D R; Silvester, W B

    1993-01-01

    Frankia strains are N2-fixing actinomycetes whose isolation and cultivation were first reported in 1978. They induce N2-fixing root nodules on diverse nonleguminous (actinorhizal) plants that are important in ecological successions and in land reclamation and remediation. The genus Frankia encompasses a diverse group of soil actinomycetes that have in common the formation of multilocular sporangia, filamentous growth, and nitrogenase-containing vesicles enveloped in multilaminated lipid envelopes. The relatively constant morphology of vesicles in culture is modified by plant interactions in symbiosis to give a diverse array of vesicles shapes. Recent studies of the genetics and molecular genetics of these organisms have begun to provide new insights into higher-plant-bacterium interactions that lead to productive N2-fixing symbioses. Sufficient information about the relationship of Frankia strains to other bacteria, and to each other, is now available to warrant the creation of some species based on phenotypic and genetic criteria. Images PMID:8336669

  4. 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.

  5. Genome Sequence of Streptomyces viridosporus Strain T7A ATCC 39115, a Lignin-Degrading Actinomycete

    PubMed Central

    Davis, Jennifer R.; Goodwin, Lynne; Teshima, Hazuki; Detter, Chris; Tapia, Roxanne; Han, Cliff; Huntemann, Marcel; Wei, Chia-Lin; Han, James; Chen, Amy; Kyrpides, Nikos; Mavrommatis, Kostas; Szeto, Ernest; Markowitz, Victor; Ivanova, Natalia; Mikhailova, Natalia; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Woyke, Tanja; Pitluck, Sam; Peters, Lin; Nolan, Matt; Land, Miriam

    2013-01-01

    We announce the availability of the genome sequence of Streptomyces viridosporus strain T7A ATCC 39115, a plant biomass-degrading actinomycete. This bacterium is of special interest because of its capacity to degrade lignin, an underutilized component of plants in the context of bioenergy. It has a full complement of genes for plant biomass catabolism. PMID:23833133

  6. Genome Sequence of Streptomyces viridosporus Strain T7A ATCC 39115, a Lignin-Degrading Actinomycete

    SciTech Connect

    Davis, Jennifer R.; Goodwin, Lynne A.; Teshima, Hazuki; Detter, J. Chris; Tapia, Roxanne; Han, Cliff; Huntemann, Marcel; Wei, Chia-Lin; Han, James; Chen, Amy; Kyrpides, Nikos C; Mavromatis, K; Szeto, Ernest; Markowitz, Victor; Ivanova, N; Mikhailova, Natalia; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Woyke, Tanja; Pitluck, Sam; Peters, Lin; Nolan, Matt; Land, Miriam L; Sello, Jason K.

    2013-01-01

    We announce the availability of the genome sequence of Streptomyces viridosporus strain T7A ATCC 39115, a plant biomass- degrading actinomycete. This bacterium is of special interest because of its capacity to degrade lignin, an underutilized compo- nent of plants in the context of bioenergy. It has a full complement of genes for plant biomass catabolism.

  7. [Bioactivity of endophytic actinomycetes from medicinal plants and secondary metabolites from strain D62].

    PubMed

    Liu, Ning; Zhang, Hui; Zheng, Wen; Huang, Ying; Wang, Hai-Bin

    2007-10-01

    It is believed that genetic recombination of the endophytes with the hosts that occurred in evolutionary time could result in some endophytes producing certain phytochemical originally characteristic of the host. Based on this widely accepted hypothesis, there have been increasing research efforts focused on screening for novel natural products from endophytes. In this study, antimicrobial and antitumor activities of 165 actinomycetes isolated from medicinal plants collected from Xishuangbanna were tested by agar diffusion method and WST-8 assay respectively. The results showed that over 42% of the isolates exhibited antagonism against pathogenic strains, and 54.5% displayed excellent inhibition against mouse melanoma cell line B16 or/and human alveolar epithelial cell line A549. These results are superior to those of soil actinomycetes, indicating tremendous potential of endophytic of actinomycetes for exploration. Six compounds that had both antimicrobial and antitumor activities were separated and purified from isolate Streptomyces sp. D62 by resin adsorption, silica-gel column and sephadex chromatography, etc. On the basis of spectral analyses, they were identified as antimycin A4a (1), antimycin A7a (2), antimycin A2a (3), antimycin A1a (4), 10-hydroxy-10-methyl-dodec-2-en-1,4-olide (5) and 6-(2-(4-aminophenyl)-2-oxoethyl)-3,5-dimethyl-tetrahydropyran-2-one(6), with the last one defined as a novel compound. Based on all these results, it is convinced that endophytic actinomycetes are a promising resource for bioactive natural product discovery.

  8. Antibacterial discovery in actinomycetes strains with mutations in RNA polymerase or ribosomal protein S12.

    PubMed

    Hosaka, Takeshi; Ohnishi-Kameyama, Mayumi; Muramatsu, Hideyuki; Murakami, Kana; Tsurumi, Yasuhisa; Kodani, Shinya; Yoshida, Mitsuru; Fujie, Akihiko; Ochi, Kozo

    2009-05-01

    We show that selection of drug-resistant bacterial mutants allows the discovery of antibacterial compounds. Mutant strains of a soil-isolated Streptomyces species that does not produce antibacterials synthesize a previously unknown class of antibacterial, which we name piperidamycin. Overall, 6% of non-Streptomyces actinomycetes species and 43% of Streptomyces species that do not produce antibacterials are activated to produce them. The antibacterial-producing mutants all carried mutations in RNA polymerase and/or the ribosomal protein S12.

  9. Chromium(VI) resistance and removal by actinomycete strains isolated from sediments.

    PubMed

    Polti, Marta A; Amoroso, María J; Abate, Carlos M

    2007-03-01

    Forty-one isolated actinomycetes were used to study qualitative and semi-quantitative screening of chromium(VI) resistance. Chromate-removing activity was estimated using the Cr(VI) specific colorimetric reagent 1,5-diphenylcarbazide. Twenty percent of the isolates from El Cadillal (EC) and 14% of isolates from a copper filter plant (CFP) were able to grow at 13 mM of Cr(VI). All isolates from sugar cane (SCP) could grow up to Cr(VI) concentration of 17 mM. EC, CFP and SCP strains were able to remove 24%, 30% and more than 40% of Cr(VI), respectively. The highest and lowest Cr(VI) specific removal values were 75.5 mg g(-1) cell by M3 (CFP), and 1.5 mg g(-1) cell by C35 (EC) strains. Eleven Cr(VI) resistant strains were characterized and identified as species of the genera Streptomyces (10) and Amycolatopsis (1). Differences on actinomycete community composition between contaminated and non-contaminated soil were found. This study showed the potential capacity of actinomycetes as tools for Cr(VI) bioremediation.

  10. Characterization of cytotoxic compound from marine sediment derived actinomycete Streptomyces avidinii strain SU4

    PubMed Central

    Sudha, S; Masilamani, Selvam M

    2012-01-01

    Objective To investigate the cytotoxic activity of actinomycete isolated from marine sediment. Methods In the present study the DNA was isolated and the ITS region of 16s rRNA was amplified by polymerase chain reaction, using two universal bacterial primers, 1492R (5′-GGTTACCTTGTTAC GACTT-3′) and Eubac27F (5′-AGAGTTTGATCCTGGCTC AG-3′). The amplified products were purified using TIANgel mini purification kit, ligated to MD18-T simple vector (TaKaRa), and transformed into competent cells of Escherichia coli DH5α. 16S rRNA gene fragment was sequenced using forward primer M13F (-47) and reverse primer M13R (-48). Blast search sequence similarity was found against the existing non-redundant nucleotide sequence database thus, identified as Streptomyces sp SU, Streptomyces rubralavandulae strain SU1, Streptomyces cacaoi strain SU2, Streptomyces cavourensis strain SU3, Streptomyces avidinii strain SU4, Streptomyces globisporus strain SU5, Streptomyces variabilis strain SU6, Streptomyces coelicolor strain SU 7. Among the eight identified isolates, one actinomycete Streptomyces avidinii strain SU4 was selected for further study. Results Crude extract of the actinomycete isolate exhibited IC50 in 64.5 µg against Hep-2 cell line, 250 µg in VERO cell line. This value is very close to the criteria of cytotoxicity activity for the crude extracts, as established by the American National Cancer Institute (NCI) is in IC50 < 30 µg/mL. The GC MS analysis showed that the active principle might be 1,2-benzenedicarboxylic acid, bis(2-methylpropyl) ester (12.17%), isooctyl phthalate (15.29%) with the retention time 15.642 and 21.612, respectively. Conclusions This study clearly proves that the marine sediment derived actinomycetes with bioactive metabolites can be expected to provide high quality biological material for high throughout biochemical and anticancer screening programs. These results help us to conclude that the potential of using metabolic engineering and post

  11. Inhibition of Aspergillus parasiticus and cancer cells by marine actinomycete strains

    NASA Astrophysics Data System (ADS)

    Li, Ping; Yan, Peisheng

    2014-12-01

    Ten actinomycete strains isolated from the Yellow Sea off China's coasts were identified as belonging to two genera by 16S rDNA phylogenetic analysis: Streptomyces and Nocardiopsis. Six Streptomyces strains (MA10, 2SHXF01-3, MA35, MA05-2, MA05-2-1 and MA08-1) and one Nocardiopsis strain (MA03) were predicted to have the potential to produce aromatic polyketides based on the analysis of the KSα (ketoacyl-synthase) gene in the type II PKS (polyketides synthase) gene cluster. Four strains (MA03, MA01, MA10 and MA05-2) exhibited significant inhibitory effects on mycelia growth (inhibition rate >50%) and subsequent aflatoxin production (inhibition rate >75%) of the mutant aflatoxigenic Aspergillus parasiticus NFRI-95. The ethyl acetate extracts of the broth of these four strains displayed significant inhibitory effects on mycelia growth, and the IC50 values were calculated (MA03: 0.275 mg mL-1, MA01: 0.106 mg mL-1, MA10: 1.345 mg mL-1 and MA05-2: 1.362 mg mL-1). Five strains (2SHXF01-3, MA03, MA05-2, MA01 and MA08-1) were selected based on their high cytotoxic activities. The ethyl acetate extract of the Nocardiopsis strain MA03 was particularly noted for its high antitumor activity against human carcinomas of the cervix (HeLa), lung (A549), kidney (Caki-1) and liver (HepG2) (IC50: 2.890, 1.981, 3.032 and 2.603 μg mL-1, respectively). The extract also remarkably inhibited colony formation of HeLa cells at an extremely low concentration (0.5 μg mL-1). This study highlights that marine-derived actinomycetes are a huge resource of compounds for the biological control of aflatoxin contamination and the development of novel drugs for human carcinomas.

  12. Spontaneous and induced mutations to rifampicin, streptomycin and spectinomycin resistances in actinomycetes: mutagenic mechanisms and applications for strain improvement.

    PubMed

    Baltz, Richard H

    2014-09-01

    Chemical mutagenesis continues to be an important foundational methodology for the generation of highly productive actinomycete strains for the commercial production of antibiotics and other secondary metabolites. In the past, the determination of frequencies of chemically induced resistance to rifampicin (RifR), spectinomycin (SpcR) and streptomycin (StrR) have served as surrogate markers to monitor the efficiencies and robustness of mutagenic protocols. Recent studies indicate that high level RifR, SpcR and StrR phenotypes map to specific regions of the rpoB, rpsE and rpsL genes, respectively, in actinomycetes. Moreover, mutagenesis to RifR can occur spontaneously at many different sites in rpoB, and all six types of base-pair substitutions, as well as in-frame deletions and insertions, have been observed. The RifR/rpoB system provides a robust method to rank mutagenic protocols, to evaluate mutagen specificity and to study spontaneous mutagenesis mechanisms involved in the maintenance of high G+C content in Streptomyces species and other actinomycetes.

  13. Complete Genome Sequence of Micromonospora Strain L5, a Potential Plant-Growth-Regulating Actinomycete, Originally Isolated from Casuarina equisetifolia Root Nodules

    SciTech Connect

    Hirsch, A. M.; Alvarado, J.; Bruce, D.; Chertkov, O.; De Hoff, P. L.; Detter, J. C.; Fujishige, N. A.; Goodwin, L. A.; Han, J.; Han, S.; Ivanova, N.; Land, M. L.; Lum, M. R.; Milani-Nejad, N.; Nolan, M.; Pati, A.; Pitluck, S.; Tran, S. S.; Woyke, T.; Valdes, M.

    2013-08-29

    Micromonospora species live in diverse environments and exhibit a broad range of functions including antibiotic production, biocontrol, and ability to degrade complex polysaccharides. To learn more about these versatile actinomycetes, we sequenced the genome of strain L5, originally isolated from root nodules of an actinorhizal plant growing in Mexico.

  14. Complete Genome Sequence of Micromonospora Strain L5, a Potential Plant-Growth-Regulating Actinomycete, Originally Isolated from Casuarina equisetifolia Root Nodules

    PubMed Central

    Alvarado, Johana; Bruce, David; Chertkov, Olga; De Hoff, Peter L.; Detter, John C.; Fujishige, Nancy A.; Goodwin, Lynne A.; Han, James; Han, Shunsheng; Ivanova, Natalia; Land, Miriam L.; Lum, Michelle R.; Milani-Nejad, Nima; Nolan, Matt; Pati, Amrita; Pitluck, Sam; Tran, Stephen S.; Woyke, Tanja; Valdés, Maria

    2013-01-01

    Micromonospora species live in diverse environments and exhibit a broad range of functions, including antibiotic production, biocontrol, and degradation of complex polysaccharides. To learn more about these versatile actinomycetes, we sequenced the genome of strain L5, originally isolated from root nodules of an actinorhizal plant growing in Mexico. PMID:24072863

  15. Biosynthetic potential-based strain prioritization for natural product discovery: a showcase for diterpenoid-producing actinomycetes.

    PubMed

    Xie, Pengfei; Ma, Ming; Rateb, Mostafa E; Shaaban, Khaled A; Yu, Zhiguo; Huang, Sheng-Xiong; Zhao, Li-Xing; Zhu, Xiangcheng; Yan, Yijun; Peterson, Ryan M; Lohman, Jeremy R; Yang, Dong; Yin, Min; Rudolf, Jeffrey D; Jiang, Yi; Duan, Yanwen; Shen, Ben

    2014-02-28

    Natural products remain the best sources of drugs and drug leads and serve as outstanding small-molecule probes to dissect fundamental biological processes. A great challenge for the natural product community is to discover novel natural products efficiently and cost effectively. Here we report the development of a practical method to survey biosynthetic potential in microorganisms, thereby identifying the most promising strains and prioritizing them for natural product discovery. Central to our approach is the innovative preparation, by a two-tiered PCR method, of a pool of pathway-specific probes, thereby allowing the survey of all variants of the biosynthetic machineries for the targeted class of natural products. The utility of the method was demonstrated by surveying 100 strains, randomly selected from our actinomycete collection, for their biosynthetic potential of four classes of natural products, aromatic polyketides, reduced polyketides, nonribosomal peptides, and diterpenoids, identifying 16 talented strains. One of the talented strains, Streptomyces griseus CB00830, was finally chosen to showcase the discovery of the targeted classes of natural products, resulting in the isolation of three diterpenoids, six nonribosomal peptides and related metabolites, and three polyketides. Variations of this method should be applicable to the discovery of other classes of natural products.

  16. Bioaugmenting anaerobic digestion of biosolids with selected strains of Bacillus, Pseudomonas, and Actinomycetes species for increased methanogenesis and odor control.

    PubMed

    Duran, Metin; Tepe, Nalan; Yurtsever, Deniz; Punzi, Vito L; Bruno, Charles; Mehta, Raj J

    2006-12-01

    The objective of this study was to evaluate the effects of bioaugmenting anaerobic biosolids digestion with a commercial product containing selected strains of bacteria from genera Bacillus, Pseudomonas, and Actinomycetes, along with ancillary organic compounds containing various micronutrients. Specifically, the effects of the bioaugment in terms of volatile solids destruction and generation and fate of odor-causing compounds during anaerobic digestion and during storage of the digested biosolids were studied. Two bench-scale anaerobic digesters receiving primary and secondary clarifier biosolids from various full-scale biological wastewater treatment plants were operated. One of the digesters received the bioaugment developed by Organica Biotech, while the other was operated as control. The bioaugmented digester generated 29% more net CH(4) during the 8 weeks of operation. In addition, the average residual propionic acid concentration in the bioaugmented digester was 54% of that in the control. The monitoring of two organic sulfide compounds, methyl mercaptan (CH(3)SH) and dimethyl sulfide (CH(3)SCH(3)), clearly demonstrated the beneficial effects of the bioaugmentation in terms of odor control. The biosolids digested in the bioaugmented digester generated a negligible amount of CH(3)SH during 10 days of post-digestion storage, while CH(3)SH concentration in the control reached nearly 300 ppm(v) during the same period. Similarly, peak CH(3)SCH(3) generated by stored biosolids from the bioaugmented digester was only 37% of that from the control.

  17. Isolation and characterization of actinomycetes strains that produce phospholipase D having high transphosphatidylation activity.

    PubMed

    Nakazawa, Yozo; Uchino, Masataka; Sagane, Yoshimasa; Sato, Hiroaki; Takano, Katsumi

    2009-01-01

    The present study was conducted to screen microorganisms that produce phospholipase D (PLD), and we especially focused on the strains having high transphosphatidylation activity. Eighty bacterial strains were isolated from soil samples by a screening method utilizing a preliminary selection medium with phosphatidylcholine (PC) as the sole carbon source. The culture supernatants were then assayed for PLD activity. The finding of dual PLD activities in cultures revealed that the hydrolytic and transphosphatidylation activities were correlated. Consequently, six strains were selected as stably producing PLD enzyme(s) during continuous subcultures. The culture supernatants of selected strains synthesized phosphatidylglycerol, phosphatidylserine and phosphatidylethanolamine from PC with high conversion rates. These isolated strains will be made available to carry out phospholipid modification through the efficient transphosphatidylation activity of the PLD that they produce.

  18. A novel actinomycete strain de-replication approach based on the diversity of polyketide synthase and nonribosomal peptide synthetase biosynthetic pathways.

    PubMed

    Ayuso, Angel; Clark, Desmond; González, Ignacio; Salazar, Oscar; Anderson, Annaliesa; Genilloud, Olga

    2005-06-01

    The actinomycetes traditionally represent one of the most important sources for the discovery of new metabolites with biological activity; and many of these are described as being produced by polyketide synthases (PKS) and nonribosomal peptide synthetases (NRPS). We present a strain characterization system based on the metabolic potential of microbial strains by targeting these biosynthetic genes. After an initial evaluation of the existing bias derived from the PCR detection in a well defined biosynthetic systems, we developed a new fingerprinting approach based on the restriction analysis of these PKS and NRPS amplified sequences. This method was applied to study the distribution of PKS and NRPS biosynthetic systems in a collection of wild-type actinomycetes isolated from tropical soil samples that were evaluated for the production of antimicrobial activities. We discuss the application of this tool as an alternative characterization approach for actinomycetes and we comment on the relationship observed between the presence of PKS-I, PKS-II and NRPS sequences and the antimicrobial activities observed in some of the microbial groups tested.

  19. [Micirobial diversity and screening of antitumor activity of actinomycete strains from saline and alkaline environments in the Qinghai Province, P. R. China].

    PubMed

    Chen, Yi-Guang; Jiang, Yi; Li, Wen-Jun; Cui, Xiao-Long; Xu, Li-Hua

    2007-10-01

    Soil and sediment samples were collected from saline and alkaline soils or lakes in the Qinghai Province, northwestern China. 145 actinomycete strains were isolated using Glucose-Peptone-Yeast extract agar (GPY) and ISP medium 2 agar supplemented with 1.0 - 3.0 mol/L NaCl at pH 7.5 - 10. The antitumor activities in vitro of the fermentation broth extracts from the 145 test strains were detected in 6 human tumor cell lines (gastric cancer GXF251L, lung cancer LXFL529L, mammary cancer MAXF401NL, melanoma cancer MEXF462NL, renal cancer RXF486L and uterus cancer UXF1138L). Out of 145 test strains, 26 strains were positive in antitumor activities (17.9%), among them 19 strains belong to the genus Nocardiopsis, 7 strains belong to the genus Streptomyces. Then 8 antitumor-positive strains were submitted for 16S rRNA gene amplification and phylogenetic analysis after a comparison of antitumor activities, morphological, physiological characteristics and whole cell amino acids analysis. The results suggested that strain YIM 80139 is a member of a known Streptomyces species S. griseus, while strain YIM 80038 may represent a potential new Streptomyce species, and that the other 6 strains may represent 4 potential new species of the genus Nocardiopsis. The results presented above showed that actinomycetes isolated from saline and alkaline samples are important resources for bioactive compounds, and the abundant microbial diversity in the saline and alkaline environments in the Qinghai Province, Northwestern China is attractive for further investigation.

  20. Novel bioactive compounds from actinomycetes.

    PubMed

    Sanglier, J J; Wellington, E M; Behal, V; Fiedler, H P; Ellouz Ghorbel, R; Finance, C; Hacene, M; Kamoun, A; Kelly, C; Mercer, D K

    1993-10-01

    Actinomycetes form an enormous reservoir of secondary metabolites and enzymes. The potential for exploiting rare actinomycetes is highlighted by the discovery of novel compounds from strains of Spirillospora and Nocardioides. Novel compounds of well known classes of antibiotics, such as polyenes, continue to be discovered. For compounds containing a chromophore, the analysis by high-performance liquid chromatography coupled with a diode-array detector enables the elimination of producers of known compounds and facilitates the discovery of novel compounds or derivatives. The complexity of the regulatory mechanisms is illustrated by glutamine synthetase. The characterization of thermostable amylolytic, lignolytic, peroxidase and neuramidase activities, and the isolation of novel cellulolytic actinomycetes clearly demonstrate the potential of Actinomycetes as producers of enzymes.

  1. Metabolic Engineering of the Actinomycete Amycolatopsis sp. Strain ATCC 39116 towards Enhanced Production of Natural Vanillin

    PubMed Central

    Fleige, Christian; Meyer, Florian

    2016-01-01

    ABSTRACT The Gram-positive bacterium Amycolatopsis sp. ATCC 39116 is used for the fermentative production of natural vanillin from ferulic acid on an industrial scale. The strain is known for its outstanding tolerance to this toxic product. In order to improve the productivity of the fermentation process, the strain's metabolism was engineered for higher final concentrations and molar yields. Degradation of vanillin could be decreased by more than 90% through deletion of the vdh gene, which codes for the central vanillin catabolism enzyme, vanillin dehydrogenase. This mutation resulted in improvement of the final concentration of vanillin by more than 2.2 g/liter, with a molar yield of 80.9%. Further improvement was achieved with constitutive expression of the vanillin anabolism genes ech and fcs, coding for the enzymes feruloyl-coenzyme A (CoA) synthetase (fcs) and enoyl-CoA hydratase/aldolase (ech). The transcription of both genes was shown to be induced by ferulic acid, which explains the unwanted adaptation phase in the fermentation process before vanillin was efficiently produced by the wild-type cells. Through the constitutive and enhanced expression of the two genes, the adaptation phase was eliminated and a final vanillin concentration of 19.3 g/liter, with a molar yield of 94.9%, was obtained. Moreover, an even higher final vanillin concentration of 22.3 g/liter was achieved, at the expense of a lower molar yield, by using an improved feeding strategy. This is the highest reported vanillin concentration reached in microbial fermentation processes without extraction of the product. Furthermore, the vanillin was produced almost without by-products, with a molar yield that nearly approached the theoretical maximum. IMPORTANCE Much effort has been put into optimization of the biotechnological production of natural vanillin. The demand for this compound is growing due to increased consumer concerns regarding chemically produced food additives. Since this

  2. Development of a 16S rRNA gene-based prototype microarray for the detection of selected actinomycetes genera.

    PubMed

    Kyselková, Martina; Kopecký, Jan; Felföldi, Tamás; Cermák, Ladislav; Omelka, Marek; Grundmann, Geneviève L; Moënne-Loccoz, Yvan; Ságová-Marecková, Markéta

    2008-10-01

    Actinomycetes are known for their secondary metabolites, which have been successfully used as drugs in human and veterinary medicines. However, information on the distribution of this group of Gram-positive bacteria in diverse ecosystems and a comprehension of their activities in ecosystem processes are still scarce. We have developed a 16S rRNA-based taxonomic microarray that targets key actinomycetes at the genus level. In total, 113 actinomycete 16S rRNA probes, corresponding to 55 of the 202 described genera, were designed. The microarray accuracy was evaluated by comparing signal intensities with probe/target-weighted mismatch values and the Gibbs energy of the probe/target duplex formation by hybridizing 17 non-actinomycete and 29 actinomycete strains/clones with the probe set. The validation proved that the probe set was specific, with only 1.3% of false results. The incomplete coverage of actinomycetes by a genus-specific probe was caused by the limited number of 16S rRNA gene sequences in databases or insufficient 16S rRNA gene polymorphism. The microarray enabled discrimination between actinomycete communities from three forest soil samples collected at one site. Cloning and sequencing of 16S rRNA genes from one of the soil samples confirmed the microarray results. We propose that this newly constructed microarray will be a valuable tool for genus-level comparisons of actinomycete communities in various ecological conditions.

  3. Diversity, bioactivities, and metabolic potentials of endophytic actinomycetes isolated from traditional medicinal plants in Sichuan, China.

    PubMed

    Qiu, Peng; Feng, Zhi-Xiang; Tian, Jie-Wei; Lei, Zu-Chao; Wang, Lei; Zeng, Zhi-Gang; Chu, Yi-Wen; Tian, Yong-Qiang

    2015-12-01

    The present study was designed to determine the taxonomic diversity and metabolic activity of the actinomycetes community, including 13 traditional medicinal plants collected in Sichuan province, China, using multiple approaches such as morphological and molecular identification methods, bioactivity assays, and PCR screening for genes involved in antibiotics biosynthesis. 119 endophytic actinomycetes were recovered; 80 representative strains were chosen for 16S rRNA gene partial sequence analyses, with 66 of them being affiliated to genus Streptomyces and the remaining 14 strains being rare actinomycetes. Antimicrobial tests showed that 12 (15%) of the 80 endophytic actinomycetes displayed inhibitory effects against at least one indicator pathogens, which were all assigned to the genus Streptomyces. In addition, 87.5% and 58.8% of the isolates showed anticancer and anti-diabetic activities, respectively. Meanwhile, the anticancer activities of the isolates negatively correlated with their anti-diabetic activities. Based on the results of PCR screening, five genes, PKS-I, PKS-II, NRPS, ANSA, and oxyB, were detected in 55.0%, 58.8%, 90.0%, 18.8% and 8.8% of the 80 actinomycetes, respectively. In conclusion, the PCR screening method employed in the present study was conducive for screening and selection of potential actinomycetes and predicting potential secondary metabolites, which could overcome the limitations of traditional activity screening models.

  4. Isolation of cellulolytic actinomycetes from marine sediments

    SciTech Connect

    Veiga, M.; Esparis, A.; Fabregas, J.

    1983-07-01

    The cellulolytic activity of 36 actinomycetes strains isolated from marine sediments was investigated by the cellulose-azure method. Approximately 50% of the isolates exhibited various degrees of cellulolytic activity. 13 references.

  5. Purification and biochemical characterization of a detergent-stable keratinase from a newly thermophilic actinomycete Actinomadura keratinilytica strain Cpt29 isolated from poultry compost.

    PubMed

    Habbeche, Amina; Saoudi, Boudjema; Jaouadi, Bassem; Haberra, Soumaya; Kerouaz, Bilal; Boudelaa, Mokhtar; Badis, Abdelmalek; Ladjama, Ali

    2014-04-01

    An extracellular thermostable keratinase (KERAK-29) was purified and biochemically characterized from a thermophilic actinomycete Actinomadura keratinilytica strain Cpt29 newly isolated from Algerian poultry compost. The isolate exhibited high keratinase production when grown in chicken feather meal media (24,000 U/ml). Based on matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis, the purified enzyme is a monomer with a molecular mass of 29,233.10-Da. The data revealed that the 25 N-terminal residue sequence displayed by KERAK-29 was TQADPPSWGLNNIDRQTAFTKATSI, which showed high homology with those of Streptomyces proteases. This keratinase was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP), which suggests that it belongs to the serine protease family. Using keratin azure as a substrate, the optimum pH and temperature values for keratinase activity were pH 10 and 70°C, respectively. KERAK-29 was stable between 20 and 60°C and pH 3 and 10 for 5 and 120 h, respectively, and its thermoactivity and thermostability were enhanced in the presence of 5 mM Mn(2+). Its catalytic efficiency was higher than that of the KERAB keratinase from Streptomyces sp. strain AB1. KERAK-29 was also noted to show high keratinolytic activity and significant stability in the presence of detergents, which made it able to accomplish the entire feather-biodegradation process on its own. The ability of the A. keratinilytica strain Cpt29 to grow and produce substantial levels of keratinase using feather as a substrate could open new promising opportunities for the valorization of keratin-containing wastes and reduction of its impacts on the environment.

  6. Complete genome sequence of Streptomyces sp. strain CFMR 7, a natural rubber degrading actinomycete isolated from Penang, Malaysia.

    PubMed

    Nanthini, Jayaram; Chia, Kim-Hou; Thottathil, Gincy P; Taylor, Todd D; Kondo, Shinji; Najimudin, Nazalan; Baybayan, Primo; Singh, Siddharth; Sudesh, Kumar

    2015-11-20

    Streptomyces sp. strain CFMR 7, which naturally degrades rubber, was isolated from a rubber plantation. Whole genome sequencing and assembly resulted in 2 contigs with total genome size of 8.248 Mb. Two latex clearing protein (lcp) genes which are responsible for rubber degrading activities were identified.

  7. Actinoalloteichus hoggarensis sp. nov., an actinomycete isolated from Saharan soil.

    PubMed

    Boudjelal, Farida; Zitouni, Abdelghani; Bouras, Noureddine; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2015-06-01

    A moderately halophilic actinomycete strain, designated AH97T, was isolated from Saharan soil in the Hoggar region (south Algeria) and was subjected to polyphasic taxonomic characterization. The morphological and chemotaxonomic characteristics of the strain were consistent with those of the genus Actinoalloteichus. Results of 16S rRNA gene sequence comparison revealed that strain AH97T shared the highest degree of 16S rRNA gene sequence similarity with Actinoalloteichus hymeniacidonis DSM 45092T (99.3 %) and Actinoalloteichus nanshanensis DSM 45655T (98.7 %). However, DNA-DNA hybridization studies showed only 26.5 % relatedness with A. hymeniacidonis DSM 45092T and 28.0 % with A. nanshanensis DSM 45655T. The genotypic and phenotypic data showed that strain AH97T represents a novel species of the genus Actinoalloteichus, for which the name Actinoalloteichus hoggarensis sp. nov. is proposed, with AH97T ( = DSM 45943T = CECT 8639T) as the type strain.

  8. Salinispora pacifica sp. nov., an actinomycete from marine sediments.

    PubMed

    Ahmed, Lina; Jensen, Paul R; Freel, Kelle C; Brown, Ros; Jones, Amanda L; Kim, Byung-Yong; Goodfellow, Michael

    2013-05-01

    A polyphasic analysis was carried out to clarify the taxonomic status of four marine actinomycete strains that share a phylogenetic relationship and phenotypic characteristics with the genus Salinispora. These strains formed a distinct lineage within the Salinispora 16S rRNA and gyrB trees and were found to possess a range of phenotypic properties and DNA:DNA hybridization values that distinguished them from the type strains of the two validly named species in this genus, Salinispora tropica (CNB-440(T), ATCC BAA-916(T)) and Salinispora arenicola (CNH-643(T), ATCC BAA-917(T)). The combined genotypic and phenotypic data support this conclusion. It is proposed that the strains be designated as Salinispora pacifica sp. nov., the type strain of which is CNR-114(T) (DSMZ YYYYT = KACC 17160(T)).

  9. Selection and taxonomic identification of carotenoid-producing marine actinomycetes.

    PubMed

    Romero, Francisco; Fernández-Chimeno, Rosa Isabel; de la Fuente, Juan Luis; Barredo, José-Luis

    2012-01-01

    Carotenoids are important pigments produced by plants and many microorganisms, including fungi, microalgae, cyanobacteria, and bacteria. Marine actinomycetes are a group of bacteria that produce a variety of metabolites with economic potential. Here, we describe a general method of selecting marine actinomycetes as carotenoids' producers. The screening is carried out at two levels: the first one involves a quick selection of strains by visual color inspection, and the second consists in the analysis of the extracts by HPLC. The taxonomic analysis of the producing strains gives us an overview of the groups of actinomycetes in which carotenoids can be found.

  10. Saccharothrix hoggarensis sp. nov., an actinomycete isolated from Saharan soil.

    PubMed

    Boubetra, Dalila; Zitouni, Abdelghani; Bouras, Noureddine; Mathieu, Florence; Lebrihi, Ahmed; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2013-02-01

    An actinomycete, designated SA181(T), was isolated from Saharan soil in the Hoggar region (south Algeria) and was characterized taxonomically by using a polyphasic approach. The morphological and chemotaxonomic characteristics of the isolate were consistent with the genus Saccharothrix, and 16S rRNA gene sequence analysis confirmed that strain SA181(T) was a novel member of the genus Saccharothrix. DNA-DNA hybridization values between strain SA181(T) and its closest phylogenetic neighbours, the type strains of Saccharothrix longispora, Saccharothrix texasensis and Saccharothrix xinjiangensis, were clearly below the 70 % threshold. The genotypic and phenotypic data showed that the isolate represents a novel species of the genus Saccharothrix, for which the name Saccharothrix hoggarensis sp. nov. is proposed, with the type strain SA181(T) ( = DSM 45457(T)  = CCUG 60214(T)).

  11. High-molecular-mass multicatalytic proteinase complexes produced by the nitrogen-fixing actinomycete Frankia strain BR.

    PubMed Central

    Benoist, P; Müller, A; Diem, H G; Schwencke, J

    1992-01-01

    A major-high-molecular mass proteinase and seven latent minor proteinases were found in cell extracts and in concentrates of culture medium from Frankia sp. strain BR after nondenaturing electrophoresis in mixed gelatin-polyacrylamide gels. All of these complexes showed multicatalytic properties. Their molecular masses and their sedimentation coefficients varied from 1,300 kDa (28S) to 270 kDa (12S). The electroeluted 1,300-kDa proteinase complex dissociated into 11 low-molecular-mass proteinases (40 to 19 kDa) after sodium dodecyl sulfate activation at 30 degrees C and electrophoresis under denaturing conditions. All of these electroeluted proteinases hydrolyzed N-carbobenzoxy-Pro-Ala-Gly-Pro-4-methoxy-beta- naphthylamide, D-Val-Leu-Arg-4-methoxy-beta-naphthylamide, and Boc-Val-Pro-Arg-4-methyl-7-coumarylamide, whereas Suc-Leu-Leu-Val-Tyr-4-methyl-7-coumarylamide was cleaved only by the six lower-molecular-mass proteinases (27.5 to 19 kDa). Examination by electron microscopy of uranyl acetate-stained, electroeluted 1,300- and 650-kDa intracellular and extracellular proteinase complexes showed ring-shaped and cylindrical particles (10 to 11 nm in diameter, 15 to 16 nm long) similar to those of eukaryotic prosomes and proteasomes. Polyclonal antibodies raised against rat skeletal muscle proteasomes cross-reacted with all of the high-molecular-mass proteinase complexes and, after denaturation of the electroeluted 1,300-kDa band, with polypeptides of 35 to 38, 65, and 90 kDa. Electrophoresis of the activated cell extracts under denaturing conditions revealed 11 to 17 gelatinases from 40 to 19 kDa, including the 11 proteinases of the 1,300-kDa proteinase complex. The inhibition pattern of these proteinases is complex. Thiol-reactive compounds and 1-10-phenanthroline strongly inhibited all of the proteinases, but inhibitors against serine-type proteinases were also effective for most of them. Images PMID:1537794

  12. Marine actinomycetes: an ongoing source of novel bioactive metabolites.

    PubMed

    Subramani, Ramesh; Aalbersberg, William

    2012-12-20

    Actinomycetes are virtually unlimited sources of novel compounds with many therapeutic applications and hold a prominent position due to their diversity and proven ability to produce novel bioactive compounds. There are more than 22,000 known microbial secondary metabolites, 70% of which are produced by actinomycetes, 20% from fungi, 7% from Bacillus spp. and 1-2% by other bacteria. Among the actinomycetes, streptomycetes group are considered economically important because out of the approximately more than 10,000 known antibiotics, 50-55% are produced by this genus. The ecological role of actinomycetes in the marine ecosystem is largely neglected and various assumptions meant there was little incentive to isolate marine strains for search and discovery of new drugs. The search for and discovery of rare and new actinomycetes is of significant interest to drug discovery due to a growing need for the development of new and potent therapeutic agents. Modern molecular technologies are adding strength to the target-directed search for detection and isolation of bioactive actinomycetes, and continued development of improved cultivation methods and molecular technologies for accessing the marine environment promises to provide access to this significant new source of chemical diversity with novel/rare actinomycetes including new species of previously reported actinomycetes.

  13. Evolution of cyclizing 5-aminolevulinate synthases in the biosynthesis of actinomycete secondary metabolites: outcomes for genetic screening techniques.

    PubMed

    Petříčková, Kateřina; Chroňáková, Alica; Zelenka, Tomáš; Chrudimský, Tomáš; Pospíšil, Stanislav; Petříček, Miroslav; Krištůfek, Václav

    2015-01-01

    A combined approach, comprising PCR screening and genome mining, was used to unravel the diversity and phylogeny of genes encoding 5-aminolevulinic acid synthases (ALASs, hemA gene products) in streptomycetes-related strains. In actinomycetes, these genes were believed to be directly connected with the production of secondary metabolites carrying the C5N unit, 2-amino-3-hydroxycyclopent-2-enone, with biological activities making them attractive for future use in medicine and agriculture. Unlike "classical" primary metabolism ALAS, the C5N unit-forming cyclizing ALAS (cALAS) catalyses intramolecular cyclization of nascent 5-aminolevulinate. Specific amino acid sequence changes can be traced by comparison of "classical" ALASs against cALASs. PCR screening revealed 226 hemA gene-carrying strains from 1,500 tested, with 87% putatively encoding cALAS. Phylogenetic analysis of the hemA homologs revealed strain clustering according to putative type of metabolic product, which could be used to select producers of specific C5N compound classes. Supporting information was acquired through analysis of actinomycete genomic sequence data available in GenBank and further genetic or metabolic characterization of selected strains. Comparison of 16S rRNA taxonomic identification and BOX-PCR profiles provided evidence for numerous horizontal gene transfers of biosynthetic genes or gene clusters within actinomycete populations and even from non-actinomycete organisms. Our results underline the importance of environmental and evolutionary data in the design of efficient techniques for identification of novel producers.

  14. Terrabacter lapilli sp. nov., an actinomycete isolated from stone.

    PubMed

    Lee, Jeong-Eon; Seo, Jae Pyo; Lee, Dong Wan; Ko, Young-Hwan; Lee, Soon Dong

    2008-05-01

    A novel actinomycete, designated strain LR-26T, was isolated from a small stone collected from an agricultural field in Jeju, Republic of Korea. Cells of the organism were strictly aerobic, Gram-positive, non-motile, short rods. Colonies were bright yellow, circular, smooth and translucent. The organism was characterized chemotaxonomically as having ll-diaminopimelic acid in the cell wall, MK-8(H4) as major menaquinone, a polar lipid profile including diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and unknown phospholipids, iso-C15 : 0 as the predominant fatty acid and a DNA G+C content of 72.6 mol%. Comparative 16S rRNA gene sequence analysis showed that the organism was related to the genera Intrasporangium, Terracoccus and Terrabacter within the family Intrasporangiaceae. The closest phylogenetic relatives of strain LR-26T were the type strains of Terrabacter terrae (99.4 % 16S rRNA gene sequence similarity), Terrabacter aerolatus (99.3 %) and Terrabacter tumescens (99.3 %). DNA-DNA hybridization experiments showed that strain LR-26T shared low levels of DNA-DNA relatedness with Terrabacter terrae LMG 22921T (17.6 and 22.8 % from reciprocal experiments) and with Terrabacter tumescens IMSNU 21313T (27.6 and 34.9 %). The phenotypic data and low levels of DNA-DNA relatedness readily distinguished strain LR-26T from the type strains of recognized species of the genus Terrabacter, and showed that it therefore represents a novel species. The name Terrabacter lapilli sp. nov. is proposed for this novel actinomycete. The type strain is LR-26T (=JBRI 2002T =KCTC 19199T =DSM 18583T).

  15. Biodegradation of the herbicide Diuron in soil by indigenous actinomycetes.

    PubMed

    Esposito, E; Paulillo, S M; Manfio, G P

    1998-08-01

    Three actinomycete strains isolated from soil treated with 2,4-D were able to degrade the herbicide Diuron in vitro. Strain CCT 4916 was the most efficient, degrading up to 37% of applied Diuron (100 mg Kg-1 soil) in 7 days, as measured by HPLC and UV/VIS spectroscopy. All strains showed protease and urease activity; intracellular activity of metapyrocatechase and pyrocatechase were not found. Actinomycete strain CCT 4916 produced manganese peroxidase, which could be potentially related to degradation of Diuron.

  16. Streptomyces koyangensis sp. nov., a novel actinomycete that produces 4-phenyl-3-butenoic acid.

    PubMed

    Lee, Jee Yeon; Lee, Jung Yeop; Jung, Ho Won; Hwang, Byung Kook

    2005-01-01

    A 4-phenyl-3-butenoic acid-producing actinomycete, designated strain VK-A60T, was isolated from a soil sample collected from Koyang, Korea. Morphological and chemical characteristics of the strain were consistent with those of the genus Streptomyces. The cell wall of the strain contains LL-diaminopimelic acid. The predominant fatty acids are anteiso-C(15 : 0), iso-C(16 : 0) and C(16 : 0). The strain formed a distinct monophyletic line within the 16S rRNA gene sequence phylogenetic tree. Analyses of its morphological, physiological and biochemical characteristics, together with random amplified polymorphic DNA and DNA-DNA relatedness data, confirmed that strain VK-A60T represents a novel Streptomyces taxon that is distinguishable from closely related reference strains. Strain VK-A60T (=KCCM 10555T=NBRC 100598T) is proposed as the type strain of a novel species, for which the name Streptomyces koyangensis sp. nov. is proposed.

  17. Microbispora bryophytorum sp. nov., an actinomycete isolated from moss (Bryophyta).

    PubMed

    Li, Chuang; Zhang, Yuejing; Liu, Chongxi; Wang, Haiyan; Zhao, Junwei; Li, Lianjie; Zhang, Zhongwen; Wang, Xiangjing; Xiang, Wensheng

    2015-04-01

    A novel endophytic actinomycete, designated strain NEAU-TX2-2(T), was isolated from moss and characterized using a polyphasic approach. The isolate was found to have morphological characteristics typical of the genus Microbispora . The isolate formed longitudinally paired spores on the tips of short sporophores that branched from aerial hyphae. Analysis of the 16S rRNA gene sequence supported the assignment of the novel strain to the genus Microbispora , and strain NEAU-TX2-2(T) exhibited 99.08 and 98.62% gene sequence similarities to Microbispora amethystogenes JCM 3021(T) and Microbispora rosea subsp. rosea JCM 3006(T), respectively. However two tree-making algorithms supported the position that strain NEAU-TX2-2(T) formed a distinct clade with M. rosea subsp. rosea JCM 3006(T). A low level of DNA-DNA relatedness allowed the isolate to be differentiated from M. amethystogenes JCM 3021(T) and M. rosea subsp. rosea JCM 3006(T). Moreover, strain NEAU-TX2-2(T) could also be distinguished from its closest phylogenetic relatives by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-TX2-2(T) represents a novel species of the genus Microbispora for which the name Microbispora bryophytorum sp. nov. is proposed. The type strain is NEAU-TX2-2(T) ( = CGMCC 4.7138(T) = DSM 46710(T)).

  18. Actinopolyspora algeriensis sp. nov., a novel halophilic actinomycete isolated from a Saharan soil.

    PubMed

    Meklat, Atika; Bouras, Noureddine; Zitouni, Abdelghani; Mathieu, Florence; Lebrihi, Ahmed; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2012-09-01

    A halophilic actinomycete strain designated H19(T), was isolated from a Saharan soil in the Bamendil region (Ouargla province, South Algeria) and was characterized taxonomically by using a polyphasic approach. The morphological and chemotaxonomic characteristics of the strain were consistent with those of members of the genus Actinopolyspora, and 16S rRNA gene sequence analysis confirmed that strain H19(T) was a novel species of the genus Actinopolyspora. DNA-DNA hybridization value between strain H19(T) and the nearest Actinopolyspora species, A. halophila, was clearly below the 70 % threshold. The genotypic and phenotypic data showed that the organism represents a novel species of the genus Actinopolyspora for which the name Actinopolyspora algeriensis sp. nov. is proposed, with the type strain H19(T) (= DSM 45476(T) = CCUG 62415(T)).

  19. [Isolation and antimicrobial activities of actinomycetes from vermicompost].

    PubMed

    Wang, Xue-jun; Yan, Shuang-lin; Min, Chang-li; Yang, Yan

    2015-02-01

    In this paper, actinomycetes were isolated from vermicompost by tablet coating method. Antimicrobial activities of actinomycetes were measured by the agar block method. Strains with high activity were identified based on morphology and biochemical characteristics, as well as 16S rDNA gene sequence analysis. The results showed that 26 strains of actinomycetes were isolated, 16 of them had antimicrobial activities to the test strains which accounts for 61.54% of all strains. Among the 16 strains, the strain QYF12 and QYF22 had higher antimicrobial activity to Micrococcus luteus, with a formed inhibition zone of 27 mm and 31 mm, respectively. While the strain QYF26 had higher antimicrobial activity to Bacillus subtilis, and the inhibition zone diameter was 21 mm. Based on the identification of strains with high activity, the strain QYF12 was identified as Streptomyces chartreusis, the strain QYF22 was S. ossamyceticus and the strain QYF26 was S. gancidicus. This study provided a theoretical basis for further separate antibacterial product used for biological control.

  20. Moderately haloalkaliphilic actinomycetes in salt-affected soils

    NASA Astrophysics Data System (ADS)

    Zvyagintsev, D. G.; Zenova, G. M.; Oborotov, G. V.

    2009-12-01

    It was found that the population density of actinomycetes in solonchaks and saline desert soils varied from hundreds to tens of thousands of colony-forming units (CFUs) per 1 g of soil depending on soil type and was by 1-3 orders of magnitude lower than the number of mycelial bacteria in main soil types. Actinomycetes grow actively in saline soils, and the length of their mycelium reaches 140 m per 1 g of soil. Domination of moderately halophilic, alkaliphilic, and haloalkaliphilic actinomycetes, which grow well under 5% NaCl and pH 8-9, is a specific feature of actinomycetal complexes in saline soils. Representatives of Streptomyces and Micromonospora genera were found among the haloalkaliphilic actinomycetes. Micromonospores demonstrated lower (than streptomycetes) adaptability to high salt concentrations. Investigation of the phylogenetic position of isolated dominant haloalkaliphilic strains of streptomycetes performed on the basis of sequencing of the gene 16S rRNA enabled identifying these strains as Streptomyces pluricolorescens and S. prunicolor.

  1. Evolution of cyclizing 5-aminolevulinate synthases in the biosynthesis of actinomycete secondary metabolites: outcomes for genetic screening techniques

    PubMed Central

    Petříčková, Kateřina; Chroňáková, Alica; Zelenka, Tomáš; Chrudimský, Tomáš; Pospíšil, Stanislav; Petříček, Miroslav; Krištůfek, Václav

    2015-01-01

    A combined approach, comprising PCR screening and genome mining, was used to unravel the diversity and phylogeny of genes encoding 5-aminolevulinic acid synthases (ALASs, hemA gene products) in streptomycetes-related strains. In actinomycetes, these genes were believed to be directly connected with the production of secondary metabolites carrying the C5N unit, 2-amino-3-hydroxycyclopent-2-enone, with biological activities making them attractive for future use in medicine and agriculture. Unlike “classical” primary metabolism ALAS, the C5N unit-forming cyclizing ALAS (cALAS) catalyses intramolecular cyclization of nascent 5-aminolevulinate. Specific amino acid sequence changes can be traced by comparison of “classical” ALASs against cALASs. PCR screening revealed 226 hemA gene-carrying strains from 1,500 tested, with 87% putatively encoding cALAS. Phylogenetic analysis of the hemA homologs revealed strain clustering according to putative type of metabolic product, which could be used to select producers of specific C5N compound classes. Supporting information was acquired through analysis of actinomycete genomic sequence data available in GenBank and further genetic or metabolic characterization of selected strains. Comparison of 16S rRNA taxonomic identification and BOX-PCR profiles provided evidence for numerous horizontal gene transfers of biosynthetic genes or gene clusters within actinomycete populations and even from non-actinomycete organisms. Our results underline the importance of environmental and evolutionary data in the design of efficient techniques for identification of novel producers. PMID:26300877

  2. Bioweathering and biotransformation of granitic rock minerals by actinomycetes.

    PubMed

    Abdulla, Hesham

    2009-11-01

    Actinomycetes inhabiting granitic rocks at St. Katherine, Egypt were investigated for their bioweathering potential. Actinomycete counts ranged between 174 and 360 colony forming units per gram. Counts were positively correlated to rock porosity (r = 0.65) and negatively correlated to rock salinity (r = -0.56). Sixty-six actinomycete isolates originating from rocks could be assigned into eight genera, with a high frequency of Nocardioides and Streptomyces. Organic acids were produced by 97% of the isolates. Strains belonging to Actinopolyspora, Actinomadura, Kitasatospora, Nocardioides, and Kibdelosporangium showed the highest acid production indices. Representatives from all eight genera could precipitate metals Cu, Fe, Zn, Cd, and Ag up to concentrations of 2.5 mM each. An actinomycete consortium of two Nocardioides strains and one Kibdelosporangium strain was studied for its potential to cause rock weathering in batch experiments. Results indicated a high ability of the consortium to leach the metals Cu, Zn, and Fe up to 2.6-, 2.1-, and 1.3-fold, respectively, compared to the control after 4 weeks. The pH significantly decreased after 1 week, which was parallel to an increased release of phosphate and sulfate reaching a 2.2- and 2.5-fold increase, respectively, compared to control. Highly significant weight loss (p = 0.005) was achieved by the consortium, indicating a potential multiple role of actinomycetes in weathering by acid production, metal leaching, and solubilization of phosphate and sulfate. This study emphasizes the diverse and unique abilities of actinomycetes inhabiting rock surfaces which could be of potential biotechnological applications, such as in the bioremediation of metal-contaminated environments and metal biorecovery.

  3. Actinomycete integrative and conjugative elements

    PubMed Central

    te Poele, Evelien M.; Bolhuis, Henk

    2008-01-01

    This paper reviews current knowledge on actinomycete integrative and conjugative elements (AICEs). The best characterised AICEs, pSAM2 of Streptomyces ambofaciens (10.9 kb), SLP1 (17.3 kb) of Streptomyces coelicolor and pMEA300 of Amycolatopsis methanolica (13.3 kb), are present as integrative elements in specific tRNA genes, and are capable of conjugative transfer. These AICEs have a highly conserved structural organisation, with functional modules for excision/integration, replication, conjugative transfer, and regulation. Recently, it has been shown that pMEA300 and the related elements pMEA100 of Amycolatopsis mediterranei and pSE211 of Saccharopolyspora erythraea form a novel group of AICEs, the pMEA-elements, based on the unique characteristics of their replication initiator protein RepAM. Evaluation of a large collection of Amycolatopsis isolates has allowed identification of multiple pMEA-like elements. Our data show that, as AICEs, they mainly coevolved with their natural host in an integrated form, rather than being dispersed via horizontal gene transfer. The pMEA-like elements could be separated into two distinct populations from different geographical origins. One group was most closely related to pMEA300 and was found in isolates from Australia and Asia and pMEA100-related sequences were present in European isolates. Genome sequence data have enormously contributed to the recent insight that AICEs are present in many actinomycete genera. The sequence data also provide more insight into their evolutionary relationships, revealing their modular composition and their likely combined descent from bacterial plasmids and bacteriophages. Evidence is accumulating that AICEs act as modulators of host genome diversity and are also involved in the acquisition of secondary metabolite clusters and foreign DNA via horizontal gene transfer. Although still speculative, these AICEs may play a role in the spread of antibiotic resistance factors into pathogenic bacteria

  4. Soil actinomycetes in the National Forest Park in northeastern China

    NASA Astrophysics Data System (ADS)

    Shirokikh, I. G.; Shirokikh, A. A.

    2017-01-01

    The taxonomic and functional structure of actinomycete complexes in the litters and upper horizons of the soils under an artificial coniferous-broad-leaved forest located around the town of Chanchun (Tszilin province, PRC). The complex of actinomycetes included representatives of the Streptomyces, Micromonospora, Streptosporangium, and Streptoverticillium genera and oligosporous forms. In the actinomycete complexes, streptomycetes prevailed in the abundance (61-95%) and frequency of occurrence (100%). In the parcels of Korean pine ( Pinus koraiensis) and Mongolian oak ( Quercus mongolica), streptomycetes of 19 species from 8 series and 4 sections were isolated. The most representative, as in European forest biomes, was the Cinereus Achromogenes series. A distinguishing feature of the streptomycete complex in the biomes studied was the high participation of species from the Imperfectus series. The verification of the functional activity of natural isolates made it possible to reveal strains with high antagonistic and cellulolytic abilities. A high similarity of actinomycete complexes was found in Eurasian forest ecosystems remote from each other, probably due to the similarity of plant polymers decomposable by actinomycetes.

  5. Isolation, Screening, and Identification of Novel Isolates of Actinomycetes from India for Antimicrobial Applications.

    PubMed

    Singh, Vineeta; Haque, Shafiul; Singh, Harshita; Verma, Jyoti; Vibha, Kumari; Singh, Rajbir; Jawed, Arshad; Tripathi, C K M

    2016-01-01

    The search for novel bioactive compounds from the natural environment has rapidly been gaining momentum with the increase in multi-drug resistant (MDR) pathogens. In the present study, the antimicrobial potential of novel actinomycetes has been evaluated by initial screening of six soil samples. Primary and secondary screening was performed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans, Candida tropicalis, Trichophyton rubrum, and other MDR bacterial and fungal test strains, thirteen active isolates were selected for further study. Microbial strains were identified on the basis of growth conditions and other biochemical characters. Five most active microbial strains were identified using 16S rRNA sequence homology and designated as Streptomyces xanthophaeus MTCC 11938, Streptomyces variabilis MTCC 12266, Streptomyces xanthochromogenes MTCC 11937, Streptomyces levis EU 124569, and Streptomyces sp. NCIM 5500. Four antibacterial and three antifungal compounds isolated from the above five isolates were purified and partially characterized using UV absorption and IR spectra. Two antibacterial metabolites, belong to chromone and peptide antibiotic, respectively. The antifungal compounds were found to be of non-polyene nature. In conclusion, we study the isolation of novel bacterial strains of actinomycetes for producing novel compounds having antibacterial and antifungal activities from the unexplored agro-ecological niches of India. Also, this study paves the way for further characterization of these isolates of Streptomyces sp. for their optimum utilization for antimicrobial purposes.

  6. Isolation, Screening, and Identification of Novel Isolates of Actinomycetes from India for Antimicrobial Applications

    PubMed Central

    Singh, Vineeta; Haque, Shafiul; Singh, Harshita; Verma, Jyoti; Vibha, Kumari; Singh, Rajbir; Jawed, Arshad; Tripathi, C. K. M.

    2016-01-01

    The search for novel bioactive compounds from the natural environment has rapidly been gaining momentum with the increase in multi-drug resistant (MDR) pathogens. In the present study, the antimicrobial potential of novel actinomycetes has been evaluated by initial screening of six soil samples. Primary and secondary screening was performed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans, Candida tropicalis, Trichophyton rubrum, and other MDR bacterial and fungal test strains, thirteen active isolates were selected for further study. Microbial strains were identified on the basis of growth conditions and other biochemical characters. Five most active microbial strains were identified using 16S rRNA sequence homology and designated as Streptomyces xanthophaeus MTCC 11938, Streptomyces variabilis MTCC 12266, Streptomyces xanthochromogenes MTCC 11937, Streptomyces levis EU 124569, and Streptomyces sp. NCIM 5500. Four antibacterial and three antifungal compounds isolated from the above five isolates were purified and partially characterized using UV absorption and IR spectra. Two antibacterial metabolites, belong to chromone and peptide antibiotic, respectively. The antifungal compounds were found to be of non-polyene nature. In conclusion, we study the isolation of novel bacterial strains of actinomycetes for producing novel compounds having antibacterial and antifungal activities from the unexplored agro-ecological niches of India. Also, this study paves the way for further characterization of these isolates of Streptomyces sp. for their optimum utilization for antimicrobial purposes. PMID:27999566

  7. Hybrid isoprenoid secondary metabolite production in terrestrial and marine actinomycetes.

    PubMed

    Gallagher, Kelley A; Fenical, William; Jensen, Paul R

    2010-12-01

    Terpenoids are among the most ubiquitous and diverse secondary metabolites observed in nature. Although actinomycete bacteria are one of the primary sources of microbially derived secondary metabolites, they rarely produce compounds in this biosynthetic class. The terpenoid secondary metabolites that have been discovered from actinomycetes are often in the form of biosynthetic hybrids called hybrid isoprenoids (HIs). HIs include significant structural diversity and biological activity and thus are important targets for natural product discovery. Recent screening of marine actinomycetes has led to the discovery of a new lineage that is enriched in the production of biologically active HI secondary metabolites. These strains represent a promising resource for natural product discovery and provide unique opportunities to study the evolutionary history and ecological functions of an unusual group of secondary metabolites.

  8. Antibiotics production by an actinomycete isolated from the termite gut.

    PubMed

    Matsui, Toru; Tanaka, Junichi; Namihira, Tomoyuki; Shinzato, Naoya

    2012-12-01

    As well as the search for new antibiotics, a new resource or strains for the known antibiotics is also important. Microbial symbionts in the gut of termites could be regarded as one of the feasible resource for such purpose. In this study, antibiotic-producing actinomycetes were screened from symbionts of the termite gut. 16SrRNA sequence analysis for the 10 isolates revealed that they belong to actinomycetes such as Streptomyces sp., Kitasatospora sp., and Mycobacterium sp. A culture broth from one of the isolate, namely strain CA1, belonging to the genera Streptomyces exhibited antagonistic activity against actinomycetes (Micrococcus spp.), gram-positive bacteria (Bacillus spp.), and yeast (Candida spp.). The structures of 2 compounds isolated from the culture broth of the strain CA1 were identified as those of actinomycin X2 and its analog, D. This study is the first to report that some symbionts of the termite gut are antibiotic-producing actinomycetes, and suggest that the termite gut is a feasible resource for bioprospecting.

  9. Actinomycetes inhibit filamentous fungi from the cuticle of Acromyrmex leafcutter ants.

    PubMed

    Dângelo, Rômulo Augusto Cotta; de Souza, Danival José; Mendes, Thais Demarchi; Couceiro, Joel da Cruz; Lucia, Terezinha Maria Castro Della

    2016-03-01

    Actinomycetes bacteria associated with leafcutter ants produce secondary metabolites with antimicrobial properties against Escovopsis, a fungus specialized in attacking the gardens of fungus-growing ants, which denies the ants their food source. Because previous studies have used fungi isolated from fungus gardens but not from ant integument, the aims of the present study were to isolate actinomycetes associated with the cuticle of the Acromyrmex spp. and to quantify their inhibition abilities against the filamentous fungal species carried by these ants. The results demonstrated that actinomycetes had varied strain-dependent effects on several filamentous fungal species in addition to antagonistic activity against Escovopsis. The strain isolated from Acromyrmex balzani was identified as a Streptomyces species, whereas the remaining isolates were identified as different strains belonging to the genus Pseudonocardia. These findings corroborate the hypothesis that actinomycetes do not act specifically against Escovopsis mycoparasites and may have the ability to inhibit other species of pathogenic fungi.

  10. Coevolution between attine ants and actinomycete bacteria: a reevaluation.

    PubMed

    Mueller, Ulrich G; Dash, Debadutta; Rabeling, Christian; Rodrigues, Andre

    2008-11-01

    We reassess the coevolution between actinomycete bacteria and fungus-gardening (attine) ants. Actinomycete bacteria are of special interest because they are metabolic mutualists of diverse organisms (e.g., in nitrogen-fixation or antibiotic production) and because Pseudonocardia actinomycetes are thought to serve disease-suppressing functions in attine gardens. Phylogenetic information from culture-dependent and culture-independent microbial surveys reveals (1) close affinities between free-living and ant-associated Pseudonocardia, and (2) essentially no topological correspondence between ant and Pseudonocardia phylogenies, indicating frequent bacterial acquisition from environmental sources. Identity of ant-associated Pseudonocardia and isolates from soil and plants implicates these environments as sources from which attine ants acquire Pseudonocardia. Close relatives of Atta leafcutter ants have abundant Pseudonocardia, but Pseudonocardia in Atta is rare and appears at the level of environmental contamination. In contrast, actinomycete bacteria in the genera Mycobacterium and Microbacterium can be readily isolated from gardens and starter-cultures of Atta. The accumulated phylogenetic evidence is inconsistent with prevailing views of specific coevolution between Pseudonocardia, attine ants, and garden diseases. Because of frequent acquisition, current models of Pseudonocardia-disease coevolution now need to be revised. The effectiveness of Pseudonocardia antibiotics may not derive from advantages in the coevolutionary arms race with specialized garden diseases, as currently believed, but from frequent recruitment of effective microbes from environmental sources. Indeed, the exposed integumental structures that support actinomycete growth on attine ants argue for a morphological design facilitating bacterial recruitment. We review the accumulated evidence that attine ants have undergone modifications in association with actinomycete bacteria, but we find

  11. [Selective Isolation of Rare Actinomycetes from Soil].

    PubMed

    Sineva, O N; Terekhova, L P

    2015-01-01

    Many diverse methods for selective isolation of actinomycetes are used in discovery of organisms producing biologically active substances, as well as in ecological studies. Methods for isolation of rare actinomycetes from soil are reviewed.

  12. Diversity and isolation of rare actinomycetes: an overview.

    PubMed

    Tiwari, Kavita; Gupta, Rajinder K

    2013-08-01

    A renewed interest in the development of new antimicrobial agents is urgently needed to combat the increasing number of antibiotic-resistant strains of pathogenic microorganisms. Actinomycetes continue to be the mainstream supplier of antibiotics used in industry. The likelihood of discovering a new compound with novel chemical structure can be increased with intensive efforts in isolating and screening of rare genera of microorganisms to include in natural-product-screening collections. An unexpected variety of rare actinomycetes is now being isolated worldwide from previously uninvestigated diverse natural habitats, using different selective isolation methods. These isolation efforts include methods to enhance growth (enrichment) of rare actinomycetes, and eliminate unwanted microorganisms (pretreatment). To speed up the strain isolation process, knowledge about the distribution of such unexploited groups of microorganisms must also be augmented. This is a summary of using these microorganisms as new potential biological resources, and a review of almost all of the selective isolation methods, including pretreatment and enrichment techniques that have been developed to date for the isolation of rare actinomycetes.

  13. Genetic manipulation of secondary metabolite biosynthesis for improved production in Streptomyces and other actinomycetes.

    PubMed

    Baltz, Richard H

    2016-03-01

    Actinomycetes continue to be important sources for the discovery of secondary metabolites for applications in human medicine, animal health, and crop protection. With the maturation of actinomycete genome mining as a robust approach to identify new and novel cryptic secondary metabolite gene clusters, it is critical to continue developing methods to activate and enhance secondary metabolite biosynthesis for discovery, development, and large-scale manufacturing. This review covers recent reports on promising new approaches and further validations or technical improvements of existing approaches to strain improvement applicable to a wide range of Streptomyces species and other actinomycetes.

  14. Streptomyces lopnurensis sp. nov., an actinomycete isolated from soil.

    PubMed

    Zheng, Bei; Han, Xiao-Xue; Xia, Zhan-Feng; Wan, Chuan-Xing; Zhang, Li-Li

    2014-12-01

    A novel actinomycete, designated strain TRM 49590(T), was isolated from a soil sample from Lop Nur in Xinjiang Province, China. Strain TRM 49590(T) was aerobic, Gram-staining-positive, with an optimum NaCl concentration for growth of 1.5 % (w/v) and an optimum temperature for growth of 28-37 °C. The aerial mycelium was sparse, cylindrical and smooth-surfaced with irregular branches on ISP medium 4. The whole-cell sugars of strain TRM 49590(T) were ribose and glucose. The diagnostic diamino acid contained ll-diaminopimelic acid. The predominant menaquinones were MK-9(H6) and MK-9(H8), with MK-9(H4) and MK-10(H6) present in smaller amounts. The major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The G+C content of the genomic DNA was 62.2 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and phosphatidylinositol mannoside. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain TRM 49590(T) belongs to the genus Streptomyces with a sequence similarity of 97.16 % with the most closely related species Streptomyces sodiiphilus. Based on these observations, strain TRM 49590(T) is proposed to represent a novel species of the genus Streptomyces for which the name Streptomyces lopnurensis sp. nov. is suggested. The type strain is TRM 49590(T) ( = CCTCC AA 2013018(T) = NRRL B59109(T)).

  15. Biosynthetic potential of phylogenetically unique endophytic actinomycetes from tropical plants.

    PubMed

    Janso, Jeffrey E; Carter, Guy T

    2010-07-01

    The culturable diversity of endophytic actinomycetes associated with tropical, native plants is essentially unexplored. In this study, 123 endophytic actinomycetes were isolated from tropical plants collected from several locations in Papua New Guinea and Mborokua Island, Solomon Islands. Isolates were found to be prevalent in roots but uncommon in leaves. Initially, isolates were dereplicated to the strain level by ribotyping. Subsequent characterization of 105 unique strains by 16S rRNA gene sequence analysis revealed that 17 different genera were represented, and rare genera, such as Sphaerisporangium and Planotetraspora, which have never been previously reported to be endophytic, were quite prevalent. Phylogenetic analyses grouped many of the strains into clades distinct from known genera within Thermomonosporaceae and Micromonosporaceae, indicating that they may be unique genera. Bioactivity testing and liquid chromatography-mass spectrometry (LC-MS) profiling of crude fermentation extracts were performed on 91 strains. About 60% of the extracts exhibited bioactivity or displayed LC-MS profiles with spectra indicative of secondary metabolites. The biosynthetic potential of 29 nonproductive strains was further investigated by the detection of putative polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes. Despite their lack of detectable secondary metabolite production in fermentation, most were positive for type I (66%) and type II (79%) PKS genes, and all were positive for NRPS genes. These results suggest that tropical plants from New Guinea and the adjacent archipelago are hosts to unique endophytic actinomycetes that possess significant biosynthetic potential.

  16. [Actinomycetes from mangrove and their secondary metabolites].

    PubMed

    Hong, Kui

    2013-11-04

    Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. Driven by the discovery of novel natural products from marine environment, mangrove is becoming a hot spot for actinomycetes resources collection and secondary metabolites (natural products) identification as well as their biosynthesis mechanism investigation. Salinaspora A produced by a Salinispora strain isolated from Bahamas mangrove environment, is in the first clinical trial. Till the time of writing this paper, 24 genera of 11 families and 8 suborders under the actinomycetale have been reported from mangrove, among which 3 are new genera, and 31 are new species. At the same time, secondary metabolites were identified from the mangrove actinomycetes culture, including alkanoids and quinines, azalomycins, antimycins, bezamides and quinazolines, divergolides, indole derivatives, kandenols, macrocyclic dilactones, and the attractive structures, such as the Streptocarbazoles, the multicyclic indolsesquiterpenes, and xiamycin presented unique structures. Their biosynthetic mechanism has also been investigated. Most of the metabolites were isolated from streptomycetes, with a few from Micromonospora and Saccharopolyspora.

  17. Discovery of novel metabolites from marine actinomycetes.

    PubMed

    Lam, Kin S

    2006-06-01

    Recent findings from culture-dependent and culture-independent methods have demonstrated that indigenous marine actinomycetes exist in the oceans and are widely distributed in different marine ecosystems. There is tremendous diversity and novelty among the marine actinomycetes present in marine environments. Progress has been made to isolate novel actinomycetes from samples collected at different marine environments and habitats. These marine actinomycetes produce different types of new secondary metabolites. Many of these metabolites possess biological activities and have the potential to be developed as therapeutic agents. Marine actinomycetes are a prolific but underexploited source for the discovery of novel secondary metabolites.

  18. Marine actinomycetes as a source of novel secondary metabolites.

    PubMed

    Fiedler, Hans-Peter; Bruntner, Christina; Bull, Alan T; Ward, Alan C; Goodfellow, Michael; Potterat, Olivier; Puder, Carsten; Mihm, Gerhard

    2005-01-01

    A set of 600 actinomycetes strains which were isolated from marine sediments from various sites in the Pacific and Atlantic Oceans were screened for the production of bioactive secondary metabolites. Marine streptomycete strains were found to be producers of well known chemically diverse antibiotics isolated from terrestrial streptomycetes, as in the case of marine Micromonospora strains. New marine members of the rare genus Verrucosispora seem to be a promising source for novel bioactive secondary metabolites as shown in the case of the abyssomicin producing strain AB-18-032.

  19. Actinomycetes with antimicrobial activity isolated from paper wasp (Hymenoptera: Vespidae: Polistinae) nests.

    PubMed

    Madden, Anne A; Grassetti, Andrew; Soriano, Jonathan-Andrew N; Starks, Philip T

    2013-08-01

    Actinomycetes-a group of antimicrobial producing bacteria-have been successfully cultured and characterized from the nest material of diverse arthropods. Some are symbionts that produce antimicrobial chemicals found to protect nest brood and resources from pathogenic microbes. Others have no known fitness relationship with their associated insects, but have been found to produce antimicrobials in vitro. Consequently, insect nest material is being investigated as a new source of novel antimicrobial producing actinomycetes, which could be harnessed for therapeutic potential. To extend studies of actinomycete-insect associations beyond soil-substrate dwelling insects and wood boring excavators, we conducted a preliminary assessment of the actinomycetes within the nests of the paper wasp, Polistes dominulus (Christ). We found that actinomycetes were readily cultured from nest material across multiple invasive P. dominulus populations-including members of the genera Streptomyces, Micromonospora, and Actinoplanes. Thirty of these isolates were assayed for antimicrobial activity against the challenge bacteria Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Serratia marcescens, and Bacillus subtilis. Sixty percent of isolates inhibited the growth of at least one challenge strain. This study provides the first assessment of bacteria associated with nests of P. dominulus, and the first record of antimicrobial producing actinomycetes isolated from social wasps. We provide a new system to explore nest associated actinomycetes from a ubiquitous and cosmopolitan group of insects.

  20. Friedmanniella flava sp. nov., a soil actinomycete.

    PubMed

    Zhang, Xuefang; Zhang, Jianli; Zhang, Yabo; Xin, Yuhua; He, Hongju

    2013-05-01

    A novel actinomycete, strain W6(T), was isolated from a soil sample of Yunnan Province, China. The bacterium was aerobic, non-motile, non-spore-forming and Gram-stain-positive. Genetic, phenotypic and chemical properties of the isolate were studied. 16S rRNA gene sequence data suggested that the novel isolate belonged to the genus Friedmanniella and shared 98.6% sequence similarity with Friedmanniella antarctica DSM 11053(T) and Friedmanniella okinawensis DSM 21744(T), the most closely related species. The cell-wall peptidoglycan contained ll-diaminopimelic acid, and mycolic acids were absent. The main menaquinone was MK-9(H4) and the predominant fatty acids were anteiso-C15:0 and iso-C15:0. The phospholipid profile contained phosphatidylglycerol, phosphatidylinositol, phosphatidylcholine and diphosphatidylglycerol. The DNA G+C content of strain W6(T) was 72 mol%. Strain W6(T) showed 30.0% and 28.5% DNA-DNA relatedness, respectively, to F. antarctica DSM 11053(T) and F. okinawensis DSM 21744(T). The combined genotypic and phenotypic data showed that strain W6(T) should be assigned to the genus Friedmanniella as a representative of a novel species, for which the name Friedmanniella flava sp. nov. is proposed. The type strain is W6(T) ( = CGMCC 4.6856(T) =JCM 17701(T)).

  1. Entomopathogenic marine actinomycetes as potential and low-cost biocontrol agents against bloodsucking arthropods.

    PubMed

    Loganathan, Karthik; Kumar, Gaurav; Kirthi, Arivarasan Vishnu; Rao, Kokati Venkata Bhaskara; Rahuman, Abdul Abdul

    2013-11-01

    A novel approach to control strategies for integrated blood-feeding parasite management is in high demand, including the use of biological control agents. The present study aims to determine the efficacy of optimized crude extract of actinomycetes strain LK1 as biological control agent against the fourth-instar larvae of Anopheles stephensi and Culex tritaeniorhynchus (Diptera: Culicidae) and adults of Haemaphysalis bispinosa, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae), and Hippobosca maculata (Diptera: Hippoboscidae). Antiparasitic activity was optimized using the Plackett-Burman method, and the design was developed using the software Design-Expert version 8.0.7.1. The production of the optimized crude actinomycetes LK1 strain extract was performed using response surface methodology to optimize the process parameters of protease inhibitor activity of marine actinobacteria for the independent variables like pH, temperature, glucose, casein, and NaCl at two levels (-1 and +1). The potential actinomycetes strain was identified as Saccharomonas spp., and the metamodeling surface simulation procedure was followed. It was studied using a computer-generated experimental design, automatic control of simulation experiments, and sequential optimization of the metamodels fitted to a simulation response surface function. The central composite design (CCD) used for the analysis of treatment showed that a second-order polynomial regression model was in good agreement with the experimental results at R (2) = 0.9829 (p < 0.05). The optimized values of the variables for antioxidant production were pH 6.00, glucose 1.3%, casein 0.09%, temperature 31.23 °C, and NaCl 0.10%. The LK1 strain-optimized crude extract was purified using reversed-phase high-pressure liquid chromatography, and the isolated protease inhibitor showed antiparasitic activity. The antiparasitic activity of optimized crude extract of LK1 was tested against larvae of A. stephensi (LC₅₀ = 31.82 ppm

  2. Production of Ramoplanin and Ramoplanin Analogs by Actinomycetes.

    PubMed

    de la Cruz, Mercedes; González, Ignacio; Parish, Craig A; Onishi, Russell; Tormo, José R; Martín, Jesús; Peláez, Fernando; Zink, Debbie; El Aouad, Noureddine; Reyes, Fernando; Genilloud, Olga; Vicente, Francisca

    2017-01-01

    Ramoplanin is a glycolipodepsipeptide antibiotic obtained from fermentation of Actinoplanes sp. ATCC 33076 that exhibits activity against clinically important multi-drug-resistant, Gram-positive pathogens including vancomycin-resistant Enterococcus (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-intermediate resistant Clostridium difficile. It disrupts bacterial cell wall through a unique mechanism of action by sequestering the peptidoglycan intermediate Lipid II and therefore does not show cross-resistance with other antibiotics. However, while demonstrating excellent antimicrobial activity in systemic use in animal models of infection, ramoplanin presents low local tolerability when injected intravenously. As a consequence of this limitation, new derivatives are desirable to overcome this issue. During a natural product screening program developed to discover compounds that disrupt bacterial cell wall synthesis by inhibiting peptidoglycan transglycosylation through binding to the intermediate Lipid II, 49 actinomycete strains were identified by HR-LCMS as producers of ramoplanin-related compounds. The producing strains were isolated from environmental samples collected worldwide comprising both tropical and temperate areas. To assess the diversity of this microbial population, the 49 isolates were initially identified to the genus level on the basis of their micromorphology, and 16S sequencing confirmed the initial identification of the strains. These analyses resulted in the identification of members of genus Streptomyces, as well as representatives of the families Micromonosporaceae, Nocardiaceae, Thermomonosporaceae, and Pseudonocardiaceae, suggesting that the production of ramoplanins is relatively widespread among Actinomycetes. In addition, all of these isolates were tested against a panel of Gram-positive and Gram-negative bacteria, filamentous fungi, and yeast in order to further characterize their antimicrobial properties. This

  3. Production of Ramoplanin and Ramoplanin Analogs by Actinomycetes

    PubMed Central

    de la Cruz, Mercedes; González, Ignacio; Parish, Craig A.; Onishi, Russell; Tormo, José R.; Martín, Jesús; Peláez, Fernando; Zink, Debbie; El Aouad, Noureddine; Reyes, Fernando; Genilloud, Olga; Vicente, Francisca

    2017-01-01

    Ramoplanin is a glycolipodepsipeptide antibiotic obtained from fermentation of Actinoplanes sp. ATCC 33076 that exhibits activity against clinically important multi-drug-resistant, Gram-positive pathogens including vancomycin-resistant Enterococcus (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-intermediate resistant Clostridium difficile. It disrupts bacterial cell wall through a unique mechanism of action by sequestering the peptidoglycan intermediate Lipid II and therefore does not show cross-resistance with other antibiotics. However, while demonstrating excellent antimicrobial activity in systemic use in animal models of infection, ramoplanin presents low local tolerability when injected intravenously. As a consequence of this limitation, new derivatives are desirable to overcome this issue. During a natural product screening program developed to discover compounds that disrupt bacterial cell wall synthesis by inhibiting peptidoglycan transglycosylation through binding to the intermediate Lipid II, 49 actinomycete strains were identified by HR-LCMS as producers of ramoplanin-related compounds. The producing strains were isolated from environmental samples collected worldwide comprising both tropical and temperate areas. To assess the diversity of this microbial population, the 49 isolates were initially identified to the genus level on the basis of their micromorphology, and 16S sequencing confirmed the initial identification of the strains. These analyses resulted in the identification of members of genus Streptomyces, as well as representatives of the families Micromonosporaceae, Nocardiaceae, Thermomonosporaceae, and Pseudonocardiaceae, suggesting that the production of ramoplanins is relatively widespread among Actinomycetes. In addition, all of these isolates were tested against a panel of Gram-positive and Gram-negative bacteria, filamentous fungi, and yeast in order to further characterize their antimicrobial properties. This

  4. [Distribution and characteristics of soil antagonistic actinomycetes on northern slope of Taibai Mountain, Qinling].

    PubMed

    Zhu, Wen-Jie; Xue, Quan-Hong; Cao, Yan-Ru; Xue, Lei; Shen, Guang-Hui; Lai, Hang-Xian

    2011-11-01

    Twelve representative soil samples were collected from different altitudes on the northern slope of Taibai Mountain to study the distribution and characteristics of soil antagonistic actinomyces by using agar block method. There existed a great deal of soil antagonistic actinomyces in the study area. Among the 141 actinomycete strains isolated, 116 strains (82.3%) showed antagonism toward 12 target bacteria or fungi. The antagonistic strains at altitudes 800-1845, 3488, 3655, and 3670 m occupied 73.7% -86.8%, 81.3%, 78.9% and 82.3% of the total, respectively. 42.1% of the strains at altitudes 1200-2300 m and > 3400 m showed strong and broad spectrum antagonistic activity, suggesting that there was a great potential for the isolation of actinomycete strains with strong anti-biotic capability at these altitudes. 24.1% of the antagonistic actinomycetes showed antagonism against Staphyloccocus aureu, and 2.4%, 6.9% and 11.2% of them showed activity toward Verticillium dahliae in cotton, Phytophthora sp. in strawberry and Neonectria radiciccla in ginseng, respectively. This study showed that the soil actinomycete antagonistic potentiality (SAAP) could be used as a quantitative indicator to evaluate the potential of antagonistic actinomycete resources in soil.

  5. Actinomycetes from the South China Sea sponges: isolation, diversity, and potential for aromatic polyketides discovery

    PubMed Central

    Sun, Wei; Zhang, Fengli; He, Liming; Karthik, Loganathan; Li, Zhiyong

    2015-01-01

    Marine sponges often harbor dense and diverse microbial communities including actinobacteria. To date no comprehensive investigation has been performed on the culturable diversity of the actinomycetes associated with South China Sea sponges. Structurally novel aromatic polyketides were recently discovered from marine sponge-derived Streptomyces and Saccharopolyspora strains, suggesting that sponge-associated actinomycetes can serve as a new source of aromatic polyketides. In this study, a total of 77 actinomycete strains were isolated from 15 South China Sea sponge species. Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 12 families and 20 genera, among which three rare genera (Marihabitans, Polymorphospora, and Streptomonospora) were isolated from marine sponges for the first time. Subsequently, β-ketoacyl synthase (KSα) gene was used as marker for evaluating the potential of the actinomycete strains to produce aromatic polyketides. As a result, KSα gene was detected in 35 isolates related to seven genera (Kocuria, Micromonospora, Nocardia, Nocardiopsis, Saccharopolyspora, Salinispora, and Streptomyces). Finally, 10 strains were selected for small-scale fermentation, and one angucycline compound was detected from the culture extract of Streptomyces anulatus strain S71. This study advanced our knowledge of the sponge-associated actinomycetes regarding their diversity and potential in producing aromatic polyketides. PMID:26483773

  6. Actinomycetes biosynthetic potential: how to bridge in silico and in vivo?

    PubMed

    Rebets, Yuriy; Brötz, Elke; Tokovenko, Bogdan; Luzhetskyy, Andriy

    2014-02-01

    Actinomycetes genome sequencing and bioinformatic analyses revealed a large number of "cryptic" gene clusters coding for secondary metabolism. These gene clusters have the potential to increase the chemical diversity of natural products. Indeed, reexamination of well-characterized actinomycetes strains revealed a variety of hidden treasures. Growing information about this metabolic diversity has promoted further development of strategies to discover novel biologically active compounds produced by actinomycetes. This new task for actinomycetes genetics requires the development and use of new approaches and tools. Application of synthetic biology approaches led to the development of a set of strategies and tools to satisfy these new requirements. In this review, we discuss strategies and methods to discover small molecules produced by these fascinating bacteria and also discuss a variety of genetic instruments and regulatory elements used to activate secondary metabolism cryptic genes for the overproduction of these metabolites.

  7. Novel Actinomycete Isolated from Bulking Industrial Sludge

    PubMed Central

    White, Johanna M.; Labeda, David P.; Lechevalier, Mary P.; Owens, James R.; Jones, Daniel D.; Gauthier, Joseph J.

    1986-01-01

    A novel actinomycete was the predominant filamentous microorganism in bulking activated sludge in a bench-scale reactor treating coke plant wastewater. The bacterium was isolated and identified as an actinomycete that is biochemically and morphologically similar to Amycolatopsis orientalis; however, a lack of DNA homology excludes true relatedness. At present, the isolate (NRRL B 16216) cannot be assigned to the recognized taxa of actinomycetes. Images PMID:16347238

  8. Prauserella isguenensis sp. nov., a halophilic actinomycete isolated from desert soil.

    PubMed

    Saker, Rafika; Bouras, Noureddine; Meklat, Atika; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2015-05-01

    Two actinomycete strains, designated H225(T) and H137, were isolated from two soil samples collected from the arid region of Ahbas at Béni-Isguen (Mzab), located in the Algerian Sahara. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the novel strains should be assigned to the genus Prauserella of the family Pseudonocardiaceae , and they were therefore subjected to a polyphasic taxonomic study. These two strains contained meso-diaminopimelic acid as the diagnostic diamino acid and arabinose and galactose as major whole-cell sugars. The diagnostic phospholipid was phosphatidylethanolamine. The predominant menaquinone was MK-9(H4), and the major fatty acid was iso-C16 : 0. DNA-DNA hybridization values between strain H225(T) and its closest phylogenetic neighbours, namely Prauserella flava DSM 45265(T), Prauserella alba DSM 44590(T), Prauserella aidingensis DSM 45266(T), Prauserella salsuginis DSM 45264(T) and Prauserella sediminis DSM 45267(T), were clearly below the 70% threshold used for species delineation. The genomic DNA G+C content of strains H225(T) and H137 was 70.4 mol%. On the basis of phenotypic and genotypic data, strains H225(T) and H137(T) are considered to represent a novel species of the genus Prauserella , for which the name Prauserella isguenensis sp. nov. is proposed. The type strain is H225(T) ( =DSM 46664(T) = CECT 8577(T)).

  9. Pseudonocardia antimicrobica sp. nov., a novel endophytic actinomycete associated with Artemisia annua L. (sweet wormwood).

    PubMed

    Zhao, Guo-Zhen; Li, Jie; Qin, Yu-Li; Miao, Cui-Ping; Wei, Da-Qiao; Zhang, Si; Xu, Li-Hua; Li, Wen-Jun

    2012-09-01

    A Gram-reaction-positive, non-motile, endophytic actinomycete, designated strain YIM 63235(T), was isolated from the surface-sterilized stems of Artemisia annua L., and characterized to determine its taxonomic position. The strain YIM 63235(T) formed well-differentiated aerial and substrate mycelia on media tested. The phylogenetic tree based on 16S rRNA gene sequences showed that the new isolate formed a distinct lineage within the genus Pseudonocardia, and the strain YIM 63235(T) was closely related to Pseudonocardia parietis 04-St-002(T) (99.1%). However, DNA-DNA relatedness demonstrated that strain YIM 63235(T) was distinct from the closest phylogenetic neighbor. The chemotaxonomic properties of strain YIM 63235(T) were consistent with those of the genus Pseudonocardia: the diagnostic diamino acid of the cell-wall peptidoglycan was meso-diaminopimelic acid and MK-8(H(4)) was the predominant menaquinone. The major fatty acids were iso-C(16:0) and iso-C(16:1) H. The DNA G+C content of strain YIM 63235(T) was 71.0 mol%. On the basis of the phenotypic and phylogenetic distinctiveness, the novel isolate was identified as representing a novel species of the genus Pseudonocardia, for which the name Pseudonocardia antimicrobica sp. nov. (type strain YIM 63235(T) =CCTCC AA 208080(T)=DSM 45303(T)) is proposed.

  10. Glycomyces endophyticus sp. nov., an endophytic actinomycete isolated from the root of Carex baccans Nees.

    PubMed

    Qin, Sheng; Wang, Hai-Bin; Chen, Hua-Hong; Zhang, Yu-Qin; Jiang, Cheng-Lin; Xu, Li-Hua; Li, Wen-Jun

    2008-11-01

    An actinomycete, designated strain YIM 56134(T), was isolated from the root of a Chinese medicinal plant, Carex baccans Nees, collected from Yunnan, south-west China, and subjected to a polyphasic taxonomic study. An analysis of 16S rRNA gene sequence similarities showed that strain YIM 56134(T) was a member of the genus Glycomyces, being most closely related to Glycomyces algeriensis NRRL B-16327(T) (99.0 % similarity), Glycomyces lechevalierae DSM 44724(T) (99.0 %), Glycomyces rutgersensis IFO 14488(T) (98.9 %) and Glycomyces harbinensis IFO 14487(T) (98.7 %). Strain YIM 56134(T) could be distinguished from other established Glycomyces species on the basis of relatively low sequence similarity (<97 %). Phenotypic and chemotaxonomic data supported the affiliation of this strain to the genus Glycomyces. The results of DNA-DNA hybridization and some physiological and biochemical tests allowed differentiation of the strain from related Glycomyces species. Therefore, strain YIM 56134(T) represents a novel species of the genus Glycomyces, for which the name Glycomyces endophyticus sp. nov. is proposed. The type strain is YIM 56134(T) (=KCTC 19152(T) =DSM 45002(T)).

  11. Nonomuraea solani sp. nov., an actinomycete isolated from eggplant root (Solanum melongena L.).

    PubMed

    Wang, Xiangjing; Zhao, Junwei; Liu, Chongxi; Wang, Jidong; Shen, Yue; Jia, Feiyu; Wang, Liang; Zhang, Ji; Yu, Chao; Xiang, Wensheng

    2013-07-01

    A novel actinomycete, designated strain NEAU-Z6(T), was isolated from eggplant (Solanum melongena L.) root. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain NEAU-Z6(T) belonged to the genus Nonomuraea, with highest sequence similarity to Nonomuraea monospora PT 708(T) (98.83 %), Nonomuraea rosea GW 12687(T) (98.55 %) and Nonomuraea rhizophila YIM 67092(T) (98.02 %). Sequence similarities between strain NEAU-Z6(T) and other species of the genus Nonomuraea ranged from 97.94 % (Nonomuraea candida HMC10(T)) to 96.30 % (Nonomuraea wenchangensis 210417(T)). Key morphological, physiological and chemotaxonomic characteristics of strain NEAU-Z6(T) were congruent with the description of the genus Nonomuraea. The G+C content of the genomic DNA was 64.51 mol%. DNA-DNA relatedness and comparative analysis of physiological, biochemical and chemotaxonomic data allowed genotypic and phenotypic differentiation of strain NEAU-Z6(T) from closely related species. Thus, strain NEAU-Z6(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea solani sp. nov. is proposed. The type strain is NEAU-Z6(T) ( = CGMCC 4.7037(T) = DSM 45729(T)).

  12. Taxonomic and ecological studies of actinomycetes from Vietnam: isolation and genus-level diversity.

    PubMed

    Hop, Duong Van; Sakiyama, Yayoi; Binh, Chu Thi Thanh; Otoguro, Misa; Hang, Dinh Thuy; Miyadoh, Shinji; Luong, Dao Thi; Ando, Katsuhiko

    2011-09-01

    Actinomycetes were isolated from 109 soil and 93 leaf-litter samples collected at five sites in Vietnam between 2005 and 2008 using the rehydration-centrifugation (RC) method, sodium dodecyl sulfate-yeast extract dilution method, dry-heating method and oil-separation method in conjunction with humic acid-vitamin agar as an isolation medium. A total of 1882 strains were identified as Vietnamese (VN)-actinomycetes including 1080 (57%) streptomycetes (the genus Streptomyces isolates) and 802 (43%) non-streptomycetes. The 16S ribosomal RNA gene sequences of the VN-actinomycetes were analyzed using BLAST searches. The results showed that these isolates belonged to 53 genera distributed among 21 families. Approximately 90% of these strains were members of three families: Streptomycetaceae (1087 strains, 58%); Micromonosporaceae (516 strains, 27%); and Streptosporangiaceae (89 strains, 5%). Motile actinomycetes of the genera Actinoplanes, Kineosporia and Cryptosporangium, which have quite common morphological characteristics, were frequently isolated from leaf-litter samples using the RC method. It is possible that these three genera acquired common properties during a process of convergent evolution. By contrast, strains belonging to the suborder Streptosporangineae were exclusively isolated from soils. A comparison of the sampling sites revealed no significant difference in taxonomic diversity between these sites. Among the non-streptomycetes, 156 strains (19%) were considered as new taxa distributed into 21 genera belonging to 12 families. Interestingly, the isolation of actinomycetes from leaf-litter samples using the RC method proved to be the most efficient way to isolate new actinomycetes in Vietnam, especially the Micromonosporaceae species.

  13. Harnessing the Potential of Halogenated Natural Product Biosynthesis by Mangrove-Derived Actinomycetes

    PubMed Central

    Li, Xue-Gong; Tang, Xiao-Min; Xiao, Jing; Ma, Guang-Hui; Xu, Li; Xie, Shu-Jie; Xu, Min-Juan; Xiao, Xiang; Xu, Jun

    2013-01-01

    Mangrove-derived actinomycetes are promising sources of bioactive natural products. In this study, using homologous screening of the biosynthetic genes and anti-microorganism/tumor assaying, 163 strains of actinomycetes isolated from mangrove sediments were investigated for their potential to produce halogenated metabolites. The FADH2-dependent halogenase genes, identified in PCR-screening, were clustered in distinct clades in the phylogenetic analysis. The coexistence of either polyketide synthase (PKS) or nonribosomal peptide synthetase (NRPS) as the backbone synthetases in the strains harboring the halogenase indicated that these strains had the potential to produce structurally diversified antibiotics. As a validation, a new enduracidin producer, Streptomyces atrovirens MGR140, was identified and confirmed by gene disruption and HPLC analysis. Moreover, a putative ansamycin biosynthesis gene cluster was detected in Streptomyces albogriseolus MGR072. Our results highlight that combined genome mining is an efficient technique to tap promising sources of halogenated natural products synthesized by mangrove-derived actinomycetes. PMID:24129229

  14. Harnessing the potential of halogenated natural product biosynthesis by mangrove-derived actinomycetes.

    PubMed

    Li, Xue-Gong; Tang, Xiao-Min; Xiao, Jing; Ma, Guang-Hui; Xu, Li; Xie, Shu-Jie; Xu, Min-Juan; Xiao, Xiang; Xu, Jun

    2013-10-14

    Mangrove-derived actinomycetes are promising sources of bioactive natural products. In this study, using homologous screening of the biosynthetic genes and anti-microorganism/tumor assaying, 163 strains of actinomycetes isolated from mangrove sediments were investigated for their potential to produce halogenated metabolites. The FADH2-dependent halogenase genes, identified in PCR-screening, were clustered in distinct clades in the phylogenetic analysis. The coexistence of either polyketide synthase (PKS) or nonribosomal peptide synthetase (NRPS) as the backbone synthetases in the strains harboring the halogenase indicated that these strains had the potential to produce structurally diversified antibiotics. As a validation, a new enduracidin producer, Streptomyces atrovirens MGR140, was identified and confirmed by gene disruption and HPLC analysis. Moreover, a putative ansamycin biosynthesis gene cluster was detected in Streptomyces albogriseolus MGR072. Our results highlight that combined genome mining is an efficient technique to tap promising sources of halogenated natural products synthesized by mangrove-derived actinomycetes.

  15. Biosurfactant produced from Actinomycetes nocardiopsis A17: Characterization and its biological evaluation.

    PubMed

    Chakraborty, Samrat; Ghosh, Mandakini; Chakraborti, Srijita; Jana, Sougata; Sen, Kalyan Kumar; Kokare, Chandrakant; Zhang, Lixin

    2015-08-01

    This investigation aims to isolate an Actinomycetes strain producing a biosurfactant from the unexplored region of industrial and coal mine areas. Actinomycetes are selected for this study as their novel chemistry was not exhausted and they have tremendous potential to produce bioactive secondary metabolites. The biosurfactant was characterized and further needed to be utilized for pharmaceutical dosage form. Isolation, purification, screening, and characterization of the Actinomycetes A17 were done followed by its fermentation in optimized conditions. The cell-free supernatant was used for the extraction of the biosurfactant and precipitated by cold acetone. The dried precipitate was purified by TLC and the emulsification index, surface tension and CMC were determined. The isolated strain with preferred results was identified as Actinomycetes nocardiopsis A17 with high foam-forming properties. It gives lipase, amylase, gelatinase, and protease activity. The emulsification index was found to be 93±0.8 with surface tension 66.67 dyne/cm at the lowest concentration and cmc 0.6 μg/ml. These biosurfactants were characterized by Fourier transform infra red (FT-IR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS). Therefore, it can be concluded that the biosurfactant produced by Actinomycetes nocardiopsis sp. strain A17 was found to have satisfactory results with high surface activity and emulsion-forming ability.

  16. Antibacterial metabolites from the Actinomycete Streptomyces sp. P294.

    PubMed

    Su, Huining; Shao, Hongwei; Zhang, Keqin; Li, Guohong

    2016-02-01

    The Actinomycete strain P294 was isolated from soil and identified as Streptomyces sp. based upon the results of 16S rRNA sequence analysis. Three compounds obtained from the solid fermentation products of this strain have been determined by 1D, 2D NMR and HRMS experiments. These compounds include two new compounds angumycinones C (1) and D (2), and the known compound X-14881 E (3). All compounds were assayed for antibacterial and nematicidal activity. The results showed the three compounds had different degrees of inhibitory activity against several target bacteria but no significant toxicity against the nematode Caenorhabditis elegans.

  17. Actinopolyspora mzabensis sp. nov., a halophilic actinomycete isolated from an Algerian Saharan soil.

    PubMed

    Meklat, Atika; Bouras, Noureddine; Zitouni, Abdelghani; Mathieu, Florence; Lebrihi, Ahmed; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2013-10-01

    A halophilic actinomycete strain, designated H55(T), was isolated from Saharan soil sampled in the Mzab region (Ghardaïa, southern Algeria) and was characterized in a taxonomic study using a polyphasic approach. The cell wall was determined to contain meso-diaminopimelic acid and the characteristic whole-cell sugars were arabinose and galactose. The predominant menaquinones were found to be MK-10(H4) and MK-9(H4). The predominant cellular fatty acids were determined to be anteiso-C17 : 0, iso-C16 : 0 and iso-C15 : 0. The diagnostic phospholipid detected was phosphatidylcholine. The morphological and chemotaxonomic characteristics of the strain were consistent with those of members of the genus Actinopolyspora, and 16S rRNA gene sequence analysis confirmed that strain H55(T) was a member of this genus. DNA-DNA hybridization values between strain H55(T) and the type strains of the nearest species of the genus Actinopolyspora, Actinopolyspora erythraea and A. alba, were clearly below the 70 % threshold. The genotypic and phenotypic data showed that the organism represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora mzabensis sp. nov. is proposed, with the type strain H55(T) ( = DSM 45460(T) = CCUG 62965(T)).

  18. Actinomadura gamaensis sp. nov., a novel actinomycete isolated from soil in Gama, Chad.

    PubMed

    Abagana, Adam Yacoub; Sun, Pengyu; Liu, Chongxi; Cao, Tingting; Zheng, Weiwei; Zhao, Shanshan; Xiang, Wensheng; Wang, Xiangjing

    2016-06-01

    A novel single spore-producing actinomycete, designated strain NEAU-Gz5(T), was isolated from a soil sample from Gama, Chad. A polyphasic taxonomic study was carried out to establish the status of this strain. The diamino acid present in the cell wall is meso-diaminopimelic acid. Glucose, mannose and madurose occur in whole cell hydrolysates. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside and an unidentified glycolipid. The predominant menaquinones were identified as MK-9(H8) and MK-9(H6). The predominant cellular fatty acids were found to be C16:0, iso-C15:0, iso-C16:0 and C18:0 10-methyl. Phylogenetic analysis based on the 16S rRNA gene showed that strain NEAU-Gz5(T) belongs to the genus Actinomadura and is closely related to Actinomadura oligospora JCM 10648(T) (ATCC 43269(T); 98.3 % similarity). However, the low level of DNA-DNA relatedness and some different phenotypic characteristics allowed the strain to be distinguished from its close relatives. Therefore, it is concluded that strain NEAU-Gz5(T) represents a novel species of the genus of Actinomadura, for which the name Actinomadura gamaensis sp. nov. is proposed. The type strain is NEAU-Gz5(T) (= CGMCC 4.7301(T) = DSM 100815(T)).

  19. Analysis of actinomycete communities by specific amplification of genes encoding 16S rRNA and gel-electrophoretic separation in denaturing gradients.

    PubMed Central

    Heuer, H; Krsek, M; Baker, P; Smalla, K; Wellington, E M

    1997-01-01

    A group-specific primer, F243 (positions 226 to 243, Escherichia coli numbering), was developed by comparison of sequences of genes encoding 16S rRNA (16S rDNA) for the detection of actinomycetes in the environment with PCR and temperature or denaturing gradient gel electrophoresis (TGGE or DGGE, respectively). The specificity of the forward primer in combination with different reverse ones was tested with genomic DNA from a variety of bacterial strains. Most actinomycetes investigated could be separated by TGGE and DGGE, with both techniques giving similar results. Two strategies were employed to study natural microbial communities. First, we used the selective amplification of actinomycete sequences (E. coli positions 226 to 528) for direct analysis of the products in denaturing gradients. Second, a nested PCR providing actinomycete-specific fragments (E. coli positions 226 to 1401) was used which served as template for a PCR when conserved primers were used. The products (E. coli positions 968 to 1401) of this indirect approach were then separated by use of gradient gels. Both approaches allowed detection of actinomycete communities in soil. The second strategy allowed the estimation of the relative abundance of actinomycetes within the bacterial community. Mixtures of PCR-derived 16S rDNA fragments were used as model communities consisting of five actinomycetes and five other bacterial species. Actinomycete products were obtained over a 100-fold dilution range of the actinomycete DNA in the model community by specific PCR; detection of the diluted actinomycete DNA was not possible when conserved primers were used. The methods tested for detection were applied to monitor actinomycete community changes in potato rhizosphere and to investigate actinomycete diversity in different soils. PMID:9251210

  20. Saccharothrix tamanrassetensis sp. nov., an actinomycete isolated from Saharan soil.

    PubMed

    Boubetra, Dalila; Zitouni, Abdelghani; Bouras, Noureddine; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2015-04-01

    Actinomycete strain SA198(T), isolated from a Saharan soil sample of Algeria, was characterized taxonomically by using a polyphasic approach. Chemotaxonomic and morphological characteristics observed suggested that it was a member of the genus Saccharothrix . The 16S rRNA gene sequence analysis confirmed that strain SA198(T) was a member of the genus Saccharothrix and showed a similarity level ranging between 97.5 and 98.9% within species of the genus Saccharothrix , Saccharothrix australiensis being the most closely related. However, DNA-DNA hybridization values between strain SA198(T) and its closest phylogenetic neighbours, the type strains of S. australiensis , Saccharothrix xinjiangensis , Saccharothrix algeriensis and Saccharothrix espanaensis , were clearly below the 70% threshold. Based upon genotypic and phenotypic differences from other members of the genus, a novel species, Saccharothrix tamanrassetensis sp. nov., is proposed, with SA198(T) ( = DSM 45947(T) = CECT 8640(T)) as the type strain.

  1. Diversity and bioprospecting of culturable actinomycetes from marine sediment of the Yellow Sea, China.

    PubMed

    Xiong, Zhi-Qiang; Liu, Qiao-Xia; Pan, Zhao-Long; Zhao, Na; Feng, Zhi-Xiang; Wang, Yong

    2015-03-01

    Marine actinomycetes are a potential source of a wide variety of bioactive natural products. In this work, seven pretreatments, three selective isolation media, and five artificial seawater concentrations were used to isolate actinomycetes from the sediments collected from Yellow Sea, China. Statistical analysis showed that only the isolation medium strongly affected the total and bioactive numbers of actinomycete isolates. A total of 613 actinobacterial strains were isolated and screened for antimicrobial activities; 154 isolates showed activity against at least one of nine test drug-resistant microorganisms. Eighty-nine representatives with strong antimicrobial activity were identified phylogenetically based on 16S rRNA gene sequencing, which were assigned to five different actinomycete genera Streptomyces, Kocuria, Saccharomonospora, Micromonospora, and Nocardiopsis. Using PCR-based screening for six biosynthetic genes of secondary metabolites, all 45 isolates with acute activity have at least one biosynthetic gene, 28.8 % of which possess more than three biosynthetic genes. As a case, strain SMA-1 was selected for antimicrobial natural product discovery. Three diketopiperazine dimers including a new compound iso-naseseazine B (1) and two known compounds naseseazine B (2) and aspergilazine A (3) were isolated by bioassay-guided separation. These results suggested that actinomycetes from marine sediments are a potential resource of novel secondary metabolites and drugs.

  2. Antibacterial activity of Pseudonocardia sp. JB05, a rare salty soil actinomycete against Staphylococcus aureus.

    PubMed

    Jafari, Nesa; Behroozi, Reza; Farajzadeh, Davoud; Farsi, Mohammad; Akbari-Noghabi, Kambiz

    2014-01-01

    Staphylococcus aureus is a Gram-positive bacterium that causes many harmful and life-threatening diseases. Some strains of this bacterium are resistant to available antibiotics. This study was designed to evaluate the ability of indigenous actinomycetes to produce antibacterial compounds against S. aureus and characterize the structure of the resultant antibacterial compounds. Therefore, a slightly modified agar well diffusion method was used to determine the antibacterial activity of actinomycete isolates against the test microorganisms. The bacterial extracts with antibacterial activity were fractionated by silica gel and G-25 sephadex column chromatography. Also, the active fractions were analyzed by thin layer chromatography. Finally, the partial structure of the resultant antibacterial compound was characterized by Fourier transform infrared spectroscopy. One of the isolates, which had a broad spectrum and high antibacterial activity, was designated as Pseudonocardia sp. JB05, based on the results of biochemical and 16S rDNA gene sequence analysis. Minimum inhibitory concentration for this bacterium was 40 AU mL(-1) against S. aureus. The antibacterial activity of this bacterium was stable after autoclaving, 10% SDS, boiling, and proteinase K. Thin layer chromatography, using anthrone reagent, showed the presence of carbohydrates in the purified antibacterial compound. Finally, FT-IR spectrum of the active compound illustrated hydroxyl groups, hydrocarbon skeleton, and double bond of polygenic compounds in its structure. To the best of our knowledge, this is the first report describing the efficient antibacterial activity by a local strain of Pseudonocardia. The results presented in this work, although at the initial stage in bioactive product characterization, will possibly contribute toward the Pseudonocardia scale-up for the production and identification of the antibacterial compounds.

  3. Streptomyces gamaensis sp. nov., a novel actinomycete with antifungal activity isolated from soil in Gama, Chad.

    PubMed

    Zhao, Shanshan; Ye, Lan; Liu, Chongxi; Abagana, Adam Yacoub; Zheng, Weiwei; Sun, Pengyu; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

    2017-04-01

    During an investigation exploring potential sources of novel species and natural products, a novel actinomycete with antifungal activity, designated strain NEAU-Gz11(T), was isolated from a soil sample, which was collected from Gama, Chad. The isolate was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. 16S rRNA gene sequence similarity studies showed that strain NEAU-Gz11(T) belongs to the genus Streptomyces with high sequence similarity to Streptomyces hiroshimensis JCM 4098(T) (98.0 %). Similarities to other type strains of the genus Streptomyces were lower than 98.0 %. However, the physiological and biochemical characteristics and low levels of DNA-DNA relatedness could differentiate the isolate genotypically and phenotypically from S. hiroshimensis JCM 4098(T). Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces gamaensis sp. nov. is proposed. The type strain is NEAU-Gz11(T) (=CGMCC 4.7304(T)=DSM 101531(T)).

  4. Detection of polyketide synthase and nonribosomal peptide synthetase biosynthetic genes from antimicrobial coral-associated actinomycetes.

    PubMed

    Li, Jie; Dong, Jun-De; Yang, Jian; Luo, Xiong-Ming; Zhang, Si

    2014-10-01

    The diversity and properties of actinobacteria, predominant residents in coral holobionts, have been rarely documented. In this study, we aimed to explore the species diversity, antimicrobial activities and biosynthetic potential of culturable actinomycetes within the tissues of the scleractinian corals Porites lutea, Galaxea fascicularis and Acropora millepora from the South China Sea. A total of 70 strains representing 13 families and 15 genera of actinobacteria were isolated. The antimicrobial activity and biosynthetic potential of fifteen representative filamentous actinomycetes were estimated. Crude fermentation extracts of 6 strains exhibited comparable or greater activities against Vibrio alginolyticus than ciprofloxacin. Seven of the 15 actinomycetes strains possess type I polyketide synthases (PKS-I) and/or nonribosomal peptide synthetases (NRPS) genes. Nine tested strains possess type II polyketide synthases (PKS-II). Phylogenetic analysis based on 16S rRNA gene sequences indicated that these PKS and NRPS gene screening positive strains belong to genera Nocardiopsis, Pseudonocardia, Streptomyces, Micromonospora, Amycolatopsis and Prauserella. One PKS-I and four NRPS fragments showed <70% similarity to their closest relatives, which suggested the novelty of these genes. This study helps uncover the genetic capacity of stony coral-associated actinomycetes to produce bioactive molecules.

  5. Fatty acid biosynthesis in actinomycetes

    PubMed Central

    Gago, Gabriela; Diacovich, Lautaro; Arabolaza, Ana; Tsai, Shiou-Chuan; Gramajo, Hugo

    2011-01-01

    All organisms that produce fatty acids do so via a repeated cycle of reactions. In mammals and other animals, these reactions are catalyzed by a type I fatty acid synthase (FAS), a large multifunctional protein to which the growing chain is covalently attached. In contrast, most bacteria (and plants) contain a type II system in which each reaction is catalyzed by a discrete protein. The pathway of fatty acid biosynthesis in Escherichia coli is well established and has provided a foundation for elucidating the type II FAS pathways in other bacteria (White et al., 2005). However, fatty acid biosynthesis is more diverse in the phylum Actinobacteria: Mycobacterium, possess both FAS systems while Streptomyces species have only the multi-enzyme FAS II system and Corynebacterium species exclusively FAS I. In this review we present an overview of the genome organization, biochemical properties and physiological relevance of the two FAS systems in the three genera of actinomycetes mentioned above. We also address in detail the biochemical and structural properties of the acyl-CoA carboxylases (ACCases) that catalyzes the first committed step of fatty acid synthesis in actinomycetes, and discuss the molecular bases of their substrate specificity and the structure-based identification of new ACCase inhibitors with anti-mycobacterial properties. PMID:21204864

  6. Isolation, Taxonomy, and Antagonistic Properties of Halophilic Actinomycetes in Saharan Soils of Algeria ▿

    PubMed Central

    Meklat, Atika; Sabaou, Nasserdine; Zitouni, Abdelghani; Mathieu, Florence; Lebrihi, Ahmed

    2011-01-01

    The diversity of a population of 52 halophilic actinomycetes was evaluated by a polyphasic approach, which showed the presence of members of the Actinopolyspora, Nocardiopsis, Saccharomonospora, Streptomonospora, and Saccharopolyspora genera. One strain was considered to be a new member of the last genus, and several other strains seemed to be new species. Furthermore, 50% of strains were active against a broad range of indicators and contained genes encoding polyketide synthetases and nonribosomal peptide synthetases. PMID:21764956

  7. Isolation, taxonomy, and antagonistic properties of halophilic actinomycetes in Saharan soils of Algeria.

    PubMed

    Meklat, Atika; Sabaou, Nasserdine; Zitouni, Abdelghani; Mathieu, Florence; Lebrihi, Ahmed

    2011-09-01

    The diversity of a population of 52 halophilic actinomycetes was evaluated by a polyphasic approach, which showed the presence of members of the Actinopolyspora, Nocardiopsis, Saccharomonospora, Streptomonospora, and Saccharopolyspora genera. One strain was considered to be a new member of the last genus, and several other strains seemed to be new species. Furthermore, 50% of strains were active against a broad range of indicators and contained genes encoding polyketide synthetases and nonribosomal peptide synthetases.

  8. Renaissance in antibacterial discovery from actinomycetes.

    PubMed

    Baltz, Richard H

    2008-10-01

    The soil actinomycetes have been important sources of antibiotics, but were nearly abandoned in recent years in favor of high-throughput target-based screening of chemical libraries. The latter approach has not been productive, so it is time to reinvigorate the discovery of new antibiotics from a proven source. Recent progress has been made on antibiotic discovery from actinomycetes by using high-throughput fermentation, isolation of marine actinomycetes, mining genomes for cryptic pathways, and combinatorial biosynthesis to generate new secondary metabolites related to existing pharmacophores.

  9. Nocardiopsis algeriensis sp. nov., an alkalitolerant actinomycete isolated from Saharan soil.

    PubMed

    Bouras, Noureddine; Meklat, Atika; Zitouni, Abdelghani; Mathieu, Florence; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2015-02-01

    An alkalitolerant actinomycete strain, designated B32(T), was isolated from a Saharan soil sample collected from Adrar province (South of Algeria), and then investigated using a polyphasic taxonomic approach. The strain was observed to produce short chains of spores on the dichotomous branched aerial mycelium and formed a fragmented substrate mycelium. The optimum NaCl concentration for growth was found to be 0-5 % (w/v) and the optimum growth temperature and pH were found to be 25-35 °C and 7.0-10.0 °C, respectively. The diagnostic diamino acid in the cell-wall peptidoglycan was identified as meso-diaminopimelic acid. The predominant menaquinones of strain B32(T) were identified as MK-10 (H4) and MK-11 (H4). The major fatty acids were found to be iso-C16:0 and anteiso-C15:0. The diagnostic phospholipids detected were phosphatidylcholine, phosphatidylmethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The chemotaxonomic properties of strain B32(T) are consistent with those shared by members of the genus Nocardiopsis. 16S rRNA gene sequence analysis indicated that strain B32(T) is most closely related to Nocardiopsis alba DSM 43377(T) (98.7 %), Nocardiopsis lucentensis DSM 44048(T) (98.6 %), Nocardiopsis aegyptia DSM 44442(T) (98.6 %), Nocardiopsis sinuspersici HM6(T) (98.6 %) and Nocardiopsis arvandica HM7(T) (98.5 %). However, the DNA-DNA relatedness values between strain B32(T) and the closely related type strains were 17.9, 14.6, 31.1, 27.1 and 14.1 %, respectively. Based on the combined genotypic and phenotypic evidence, it is proposed that strain B32(T) should be classified as representative of a novel species, for which the name Nocardiopsis algeriensis sp. nov. is proposed. The type strain is B32(T) (=DSM 45462(T) = CECT 8712(T)).

  10. Streptomonospora algeriensis sp. nov., a halophilic actinomycete isolated from soil in Algeria.

    PubMed

    Meklat, Atika; Bouras, Noureddine; Riba, Amar; Zitouni, Abdelghani; Mathieu, Florence; Rohde, Manfred; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2014-08-01

    A halophilic actinomycete strain, designated H27(T), was isolated from a soil sample collected from a hypersaline habitat in Djelfa Province (North-Central Algeria), and then investigated using a polyphasic taxonomic approach. The strain was observed to produce poor aerial mycelium, which formed short chains of oval to cylindrical-shaped spores at maturity, and non fragmented substrate mycelium. The optimum NaCl concentration for growth was found to be 10-15 % (w/v) and the optimum growth temperature and pH were found to be 28-37 °C and 6-7, respectively. The diagnostic diamino acid in the cell-wall peptidoglycan was identified as meso-diaminopimelic acid. The predominant menaquinones of strain H27(T) were identified as MK-11 (H4) and MK-10 (H6). The major fatty acids were found to be iso-C16:0, anteiso-C17:0, 10 methyl C17:0 and 10 methyl C16:0. The diagnostic phospholipids detected were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol. The chemotaxonomic properties of strain H27(T) are consistent with those shared by members of the genus Streptomonospora. 16S rRNA gene sequence analysis indicated that strain H27(T) is most closely related to Streptomonospora alba DSM 44588(T) (98.8 %) and Streptomonospora flavalba DSM 45155(T) (98.7 %) whereas the DNA-DNA relatedness values between strain H27(T) and the two type strains were 17.1 and 57.9 %, respectively. Based on the combined genotypic and phenotypic evidence, it is proposed that strain H27(T) should be classified as representative of a novel species, for which the name Streptomonospora algeriensis sp. nov. is proposed. The type strain is H27(T) (=DSM 45604(T) =CCUG 63369(T) =MTCC 11563(T)).

  11. Streptomyces bryophytorum sp. nov., an endophytic actinomycete isolated from moss (Bryophyta).

    PubMed

    Li, Chuang; Jin, Pinjiao; Liu, Chongxi; Ma, Zhaoxu; Zhao, Junwei; Li, Jiansong; Wang, Xiangjing; Xiang, Wensheng

    2016-09-01

    A novel endophytic actinomycete, designated strain NEAU-HZ10(T) was isolated from moss and characterised using a polyphasic approach. The strain was found to have morphological and chemotaxonomic characteristics typical of the genus Streptomyces. Strain NEAU-HZ10(T) formed grayish aerial mycelia, which differentiated into straight to flexuous chains of cylindrical spores. The cell wall peptidoglycan was found to contain LL-diaminopimelic acid. Predominant menaquinones were identified as MK-9(H6) and MK-9(H8). The polar lipid profile was found to consist of phosphatidylethanolamine, phosphatidylinositol and two unidentified phospholipids. The major fatty acids were identified as iso-C16:0, anteiso-C15:0 and C16:0. 16S rRNA gene sequence similarity studies showed that strain NEAU-HZ10(T) belongs to the genus Streptomyces and exhibits high sequence similarity to Streptomyces cocklensis DSM 42063(T) (98.9 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-HZ10(T) clustered with S. cocklensis DSM 42063(T), Streptomyces yeochonensis CGMCC 4.1882(T) (98.7 %), Streptomyces paucisporeus CGMCC 4.2025(T) (98.4 %) and Streptomyces yanglinensis CGMCC 4.2023(T) (98.1 %). However, a combination of DNA-DNA hybridisation results and some phenotypic characteristics indicated that strain NEAU-HZ10(T) can be distinguished from its phylogenetically closely related strains. Therefore, it is proposed that strain NEAU-HZ10(T) represents a novel species of the genus Streptomyces for which the name Streptomyces bryophytorum sp. nov. is proposed. The type strain is NEAU-HZ10(T) (= CGMCC 4.7151(T) = DSM 42138(T)).

  12. Streptomyces formicae sp. nov., a novel actinomycete isolated from the head of Camponotus japonicus Mayr.

    PubMed

    Bai, Lu; Liu, Chongxi; Guo, Lifeng; Piao, Chenyu; Li, Zhilei; Li, Jiansong; Jia, Feiyu; Wang, Xiangjing; Xiang, Wensheng

    2016-02-01

    During a screening for novel and biotechnologically useful actinobacteria in insects, a novel actinomycete with antifungal activity, designated strain 1H-GS9(T), was isolated from the head of a Camponotus japonicus Mayr ant, which were collected from Northeast Agricultural University (Harbin, Heilongjiang, China). Strain 1H-GS9(T) was characterised using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. 16S rRNA gene sequence similarity studies showed that strain 1H-GS9(T) belongs to the genus Streptomyces with high sequence similarities to Streptomyces scopuliridis DSM 41917(T) (98.8 %) and Streptomyces mauvecolor JCM 5002(T) (98.6 %). However, phylogenetic analysis based on the 16S rRNA gene sequence indicated that it forms a monophyletic clade with Streptomyces kurssanovii JCM 4388(T) (98.6 %), Streptomyces xantholiticus JCM 4282(T) (98.6 %) and Streptomyces peucetius JCM 9920(T) (98.5 %). Thus, a combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain 1H-GS9(T) and the above-mentioned five strains, which further clarified their relatedness and demonstrated that strain 1H-GS9(T) could be distinguished from these strains. Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces formicae sp. nov. is proposed. The type strain is 1H-GS9(T) (=CGMCC 4.7277(T) = DSM 100524(T)).

  13. Combination of uniform design with artificial neural network coupling genetic algorithm: an effective way to obtain high yield of biomass and algicidal compound of a novel HABs control actinomycete.

    PubMed

    Cai, Guanjing; Zheng, Wei; Yang, Xujun; Zhang, Bangzhou; Zheng, Tianling

    2014-05-24

    Controlling harmful algae blooms (HABs) using microbial algicides is cheap, efficient and environmental-friendly. However, obtaining high yield of algicidal microbes to meet the need of field test is still a big challenge since qualitative and quantitative analysis of algicidal compounds is difficult. In this study, we developed a protocol to increase the yield of both biomass and algicidal compound present in a novel algicidal actinomycete Streptomyces alboflavus RPS, which kills Phaeocystis globosa. To overcome the problem in algicidal compound quantification, we chose algicidal ratio as the index and used artificial neural network to fit the data, which was appropriate for this nonlinear situation. In this protocol, we firstly determined five main influencing factors through single factor experiments and generated the multifactorial experimental groups with a U15(155) uniform-design-table. Then, we used the traditional quadratic polynomial stepwise regression model and an accurate, fully optimized BP-neural network to simulate the fermentation. Optimized with genetic algorithm and verified using experiments, we successfully increased the algicidal ratio of the fermentation broth by 16.90% and the dry mycelial weight by 69.27%. These results suggested that this newly developed approach is a viable and easy way to optimize the fermentation conditions for algicidal microorganisms.

  14. NASA LaRC Strain Gage Balance Design Concepts

    NASA Technical Reports Server (NTRS)

    Rhew, Ray D.

    1999-01-01

    The NASA Langley Research Center (LaRC) has been designing strain-gage balances for more than fifty years. These balances have been utilized in Langley's wind tunnels, which span over a wide variety of aerodynamic test regimes, as well as other ground based test facilities and in space flight applications. As a result, the designs encompass a large array of sizes, loads, and environmental effects. Currently Langley has more than 300 balances available for its researchers. This paper will focus on the design concepts for internal sting mounted strain-gage balances. However, these techniques can be applied to all force measurement design applications. Strain-gage balance concepts that have been developed over the years including material selection, sting, model interfaces, measuring, sections, fabrication, strain-gaging and calibration will be discussed.

  15. Antitumor Compounds from Marine Actinomycetes

    PubMed Central

    Olano, Carlos; Méndez, Carmen; Salas, José A.

    2009-01-01

    Chemotherapy is one of the main treatments used to combat cancer. A great number of antitumor compounds are natural products or their derivatives, mainly produced by microorganisms. In particular, actinomycetes are the producers of a large number of natural products with different biological activities, including antitumor properties. These antitumor compounds belong to several structural classes such as anthracyclines, enediynes, indolocarbazoles, isoprenoides, macrolides, non-ribosomal peptides and others, and they exert antitumor activity by inducing apoptosis through DNA cleavage mediated by topoisomerase I or II inhibition, mitochondria permeabilization, inhibition of key enzymes involved in signal transduction like proteases, or cellular metabolism and in some cases by inhibiting tumor-induced angiogenesis. Marine organisms have attracted special attention in the last years for their ability to produce interesting pharmacological lead compounds. PMID:19597582

  16. The Madeira Archipelago As a Significant Source of Marine-Derived Actinomycete Diversity with Anticancer and Antimicrobial Potential.

    PubMed

    Prieto-Davó, Alejandra; Dias, Tiago; Gomes, Sofia E; Rodrigues, Sara; Parera-Valadez, Yessica; Borralho, Pedro M; Pereira, Florbela; Rodrigues, Cecilia M P; Santos-Sanches, Ilda; Gaudêncio, Susana P

    2016-01-01

    Marine-derived actinomycetes have demonstrated an ability to produce novel compounds with medically relevant biological activity. Studying the diversity and biogeographical patterns of marine actinomycetes offers an opportunity to identify genera that are under environmental pressures, which may drive adaptations that yield specific biosynthetic capabilities. The present study describes research efforts to explore regions of the Atlantic Ocean, specifically around the Madeira Archipelago, where knowledge of the indigenous actinomycete diversity is scarce. A total of 400 actinomycetes were isolated, sequenced, and screened for antimicrobial and anticancer activities. The three most abundant genera identified were Streptomyces, Actinomadura, and Micromonospora. Phylogenetic analyses of the marine OTUs isolated indicated that the Madeira Archipelago is a new source of actinomycetes adapted to life in the ocean. Phylogenetic differences between offshore (>100 m from shore) and nearshore (< 100 m from shore) populations illustrates the importance of sampling offshore in order to isolate new and diverse bacterial strains. Novel phylotypes from chemically rich marine actinomycete groups like MAR4 and the genus Salinispora were isolated. Anticancer and antimicrobial assays identified Streptomyces, Micromonospora, and Salinispora as the most biologically active genera. This study illustrates the importance of bioprospecting efforts at unexplored regions of the ocean to recover bacterial strains with the potential to produce novel and interesting chemistry.

  17. The Madeira Archipelago As a Significant Source of Marine-Derived Actinomycete Diversity with Anticancer and Antimicrobial Potential

    PubMed Central

    Prieto-Davó, Alejandra; Dias, Tiago; Gomes, Sofia E.; Rodrigues, Sara; Parera-Valadez, Yessica; Borralho, Pedro M.; Pereira, Florbela; Rodrigues, Cecilia M. P.; Santos-Sanches, Ilda; Gaudêncio, Susana P.

    2016-01-01

    Marine-derived actinomycetes have demonstrated an ability to produce novel compounds with medically relevant biological activity. Studying the diversity and biogeographical patterns of marine actinomycetes offers an opportunity to identify genera that are under environmental pressures, which may drive adaptations that yield specific biosynthetic capabilities. The present study describes research efforts to explore regions of the Atlantic Ocean, specifically around the Madeira Archipelago, where knowledge of the indigenous actinomycete diversity is scarce. A total of 400 actinomycetes were isolated, sequenced, and screened for antimicrobial and anticancer activities. The three most abundant genera identified were Streptomyces, Actinomadura, and Micromonospora. Phylogenetic analyses of the marine OTUs isolated indicated that the Madeira Archipelago is a new source of actinomycetes adapted to life in the ocean. Phylogenetic differences between offshore (>100 m from shore) and nearshore (< 100 m from shore) populations illustrates the importance of sampling offshore in order to isolate new and diverse bacterial strains. Novel phylotypes from chemically rich marine actinomycete groups like MAR4 and the genus Salinispora were isolated. Anticancer and antimicrobial assays identified Streptomyces, Micromonospora, and Salinispora as the most biologically active genera. This study illustrates the importance of bioprospecting efforts at unexplored regions of the ocean to recover bacterial strains with the potential to produce novel and interesting chemistry. PMID:27774089

  18. Detection and identification of novel actinomycetes.

    PubMed

    Williams, S T; Locci, R; Beswick, A; Kurtböke, D I; Kuznetsov, V D; Le Monnier, F J; Long, P F; Maycroft, K A; Palma, R A; Petrolini, B

    1993-10-01

    The actinomycetes are well known as a group of filamentous, Gram-positive bacteria that produce many useful secondary metabolites, including antibiotics and enzymes. Although they have been intensively studied for both theoretical and practical objectives, there is much scope for developing our basic knowledge of the means of detection and isolation of these microbes. This session concentrated on new methods for the detection and identification of novel actinomycetes from a range of environments. Approaches to the detection of actinomycetes ranged from investigations of neglected habitats and extreme environments (e.g. alkaline soils and oil drills) to the analysis of DNA extracted from the environment and use of specific phages. The continuing problems of the identification of actinomycete isolates were also considered. Topics discussed included use of phage typing, DNA probes, and correlation between phenetic and genotypic species of Streptomyces.

  19. Actinorugispora endophytica gen. nov., sp. nov., an actinomycete isolated from Daucus carota.

    PubMed

    Liu, Min-Jiao; Zhu, Wen-Yong; Li, Jie; Zhao, Guo-Zhen; Xiong, Zhi; Park, Dong-Jin; Hozzein, Wael N; Kim, Chang-Jin; Li, Wen-Jun

    2015-08-01

    An actinomycete strain, designated YIM 690008T, was isolated from Daucus carota collected from South Korea and its taxonomic position was investigated by using a polyphasic approach. The strain grew well on most media tested and no diffusible pigment was produced. The aerial mycelium formed wrinkled single spores and short spore chains, some of which were branched. The whole-cell hydrolysates contained meso-diaminopimelic acid, glucose, mannose, ribose, galactose and rhamnose. The predominant menaquinones were MK-10(H4), MK-10(H6), MK-10(H8) and MK-10(H2). The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannosides, some unknown phospholipids, glycolipids and polar lipids. The major fatty acids were i-C16 : 0, ai-C17 : 0 and C18 : 1ω9c. The DNA G+C content of the genomic DNA was 63.1 mol%. Phylogenetic analysis indicated that the isolate belongs to the family Nocardiopsaceae. However, based on phenotypic, chemotaxonomic and genotypic data, it was concluded that strain YIM 690008T represents a novel genus and novel species of the family Nocardiopsaceae, for which the name Actinorugispora endophytica gen. nov., sp. nov. (type strain YIM 690008T = DSM 46770T = JCM 30099T = KCTC 29480T) is proposed.

  20. Actinomycetes for marine drug discovery isolated from mangrove soils and plants in China.

    PubMed

    Hong, Kui; Gao, An-Hui; Xie, Qing-Yi; Gao, Hao; Zhuang, Ling; Lin, Hai-Peng; Yu, Hai-Ping; Li, Jia; Yao, Xin-Sheng; Goodfellow, Michael; Ruan, Ji-Sheng

    2009-01-01

    The mangrove ecosystem is a largely unexplored source for actinomycetes with the potential to produce biologically active secondary metabolites. Consequently, we set out to isolate, characterize and screen actinomycetes from soil and plant material collected from eight mangrove sites in China. Over 2,000 actinomycetes were isolated and of these approximately 20%, 5%, and 10% inhibited the growth of Human Colon Tumor 116 cells, Candida albicans and Staphylococcus aureus, respectively, while 3% inhibited protein tyrosine phosphatase 1B (PTP1B), a protein related to diabetes. In addition, nine isolates inhibited aurora kinase A, an anti-cancer related protein, and three inhibited caspase 3, a protein related to neurodegenerative diseases. Representative bioactive isolates were characterized using genotypic and phenotypic procedures and classified to thirteen genera, notably to the genera Micromonospora and Streptomyces. Actinomycetes showing cytotoxic activity were assigned to seven genera whereas only Micromonospora and Streptomyces strains showed anti-PTP1B activity. We conclude that actinomycetes isolated from mangrove habitats are a potentially rich source for the discovery of anti-infection and anti-tumor compounds, and of agents for treating neurodegenerative diseases and diabetes.

  1. Actinomycetes from sediments in the Trondheim fjord, Norway: diversity and biological activity.

    PubMed

    Bredholt, Harald; Fjaervik, Espen; Johnsen, Geir; Zotchev, Sergey B

    2008-01-23

    The marine environment represents a largely untapped source for isolation of new microorganisms with potential to produce biologically active secondary metabolites. Among such microorganisms, Gram-positive actinomycete bacteria are of special interest, since they are known to produce chemically diverse compounds with a wide range of biological activities. We have set out to isolate and characterize actinomycete bacteria from the sediments in one of the largest Norwegian fjords, the Trondheim fjord, with respect to diversity and antibiotic-producing potential. Approximately 3,200 actinomycete bacteria were isolated using four different agar media from the sediment samples collected at different locations and depths (4.5 to 450 m). Grouping of the isolates first according to the morphology followed by characterization of isolates chosen as group representatives by molecular taxonomy revealed that Micromonospora was the dominating actinomycete genus isolated from the sediments. The deep water sediments contained a higher relative amount of Micromonospora compared to the shallow water samples. Nine percent of the isolates clearly required sea water for normal growth, suggesting that these strains represent obligate marine organisms. Extensive screening of the extracts from all collected isolates for antibacterial and antifungal activities revealed strong antibiotic-producing potential among them. The latter implies that actinomycetes from marine sediments in Norwegian fjords can be potential sources for the discovery of novel anti-infective agents.

  2. Elicitation of secondary metabolism in actinomycetes.

    PubMed

    Abdelmohsen, Usama Ramadan; Grkovic, Tanja; Balasubramanian, Srikkanth; Kamel, Mohamed Salah; Quinn, Ronald J; Hentschel, Ute

    2015-11-01

    Genomic sequence data have revealed the presence of a large fraction of putatively silent biosynthetic gene clusters in the genomes of actinomycetes that encode for secondary metabolites, which are not detected under standard fermentation conditions. This review focuses on the effects of biological (co-cultivation), chemical, as well as molecular elicitation on secondary metabolism in actinomycetes. Our review covers the literature until June 2014 and exemplifies the diversity of natural products that have been recovered by such approaches from the phylum Actinobacteria.

  3. Saccharopolyspora ghardaiensis sp. nov., an extremely halophilic actinomycete isolated from Algerian Saharan soil.

    PubMed

    Meklat, Atika; Bouras, Noureddine; Zitouni, Abdelghani; Sabaou, Nasserdine; Mathieu, Florence; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter

    2014-04-01

    A novel halophilic actinomycete, strain designated H53(T), was isolated from a Saharan soil sample collected from Chaâbet Ntissa, Béni-isguen, Ghardaïa (South of Algeria) and was characterized taxonomically by means of polyphasic approach. Optimal growth was found to occur at 30-35 °C, pH 6-7 and in the presence of 15-25% (w/v) NaCl. The strain was observed to produce abundant aerial mycelium, which formed long chains of rod-shaped spores at maturity, and well developed and fragmented substrate mycelium. The cell wall was determined to contain meso-diaminopimelic acid; the diagnostic whole-cell sugars were arabinose and galactose. The predominant menaquinones were found to be MK-9(H₄) and MK-9(H₆). The predominant cellular fatty acids were determined to be iso- and anteiso-C17:0, iso-C15:0, and cis9 iso-C17:1. The diagnostic phospholipid detected was phosphatidylcholine. The morphological and chemotaxonomic characteristics of the strain were consistent with those of members of the genus Saccharopolyspora. Phylogenetic analyses on the basis of the 16S ribosomal RNA (rRNA) gene sequence showed that this strain formed a distinct phyletic line within the radiation of the genus Saccharopolyspora. The 16S rRNA sequence similarities between strain H53(T) and other members of the genus Saccharopolyspora ranged from 92.1 to 94.3%. The DNA G+C content of strain H53(T) was 72.6%. The genotypic and phenotypic data showed that the strain H53(T) represents a novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora ghardaiensis sp. nov. is proposed, with the type strain H53(T) (=DSM 45606(T)=CCUG 63370(T)=CECT 8304(T)).

  4. Antibacterial agents from actinomycetes - a review.

    PubMed

    Mahajan, Girish Badrinath; Balachandran, Lakshmi

    2012-01-01

    The discovery of Penicillin in 1928 and that of Streptomycin in 1943, has been pivotal to the exploration of nature as a source of new lead molecules. Globally, the microbiologist today is acknowledged as a crucial player in the drug discovery program. The microbial products, especially those from actinomycetes have been a phenomenal success for the past seven decades. Bioprospecting for new leads are often compounded by the recurrence of known antibiotics in newer microbial isolates. Despite all these deterrents, actinomycetes have proved to be a sustained mine of novel antibiotics, which selectively destroys the pathogens without affecting the host tissues. Each of these antibiotics is unique in their mode of action. Their versatility and immense economic value is something, which is extremely noteworthy. The anti-infective turn-over of over 79 billion US dollars in 2009, includes about 166 antibiotics and derivatives such as the Beta-lactam peptide antibiotics, the macrolide polyketide erythromycin, tetracyclines, aminoglycosides, daptomycin, tigecycline, most of which are produced by actinomycetes (1). Actinomycetes continue to play a highly significant role in drug discovery and development. Among the bioactive compounds that have been obtained so far from microbes, 45 % are produced by actinomycetes, 38 % by fungi and 17 % by unicellular eubacteria (2). Further many chemically synthesized drugs owe their origin to natural sources. In this review article, we highlight the recent antibiotics from actinomycetes with emphasis on their source, structures, activity, mechanism of action and current status.

  5. Discaria trinervis - Frankia symbiosis promotion by saprophytic actinomycetes.

    PubMed

    Solans, Mariana

    2007-06-01

    The influence of saprophytic actinomycetes strains on the Discaria trinervis - Frankia actinorhizal symbiosis was investigated. Three strains out of 122 isolated from the rhizosphere and rhizoplane of D. trinervis with multiple enzymatic activities, were selected for plant growth experiments: Streptomyces (BCRU-MM40), Actinoplanes (BCRU-ME3) and Micromonospora (BCRU-MM18). Inoculated seedlings of Discaria trinervis were grown in glass tubes with vermiculite-sand for 12 weeks. They were inoculated either with a single saprophytic strain or a combination of one or two of them together with the symbiotic N(2) fixing strain Frankia BCU110501. The saprophytic strains were applied in two experimental series, i.e. mycelium + supernatant simultaneously or mycelium and supernatant (growth medium free of cells) separately. Micromonospora strain MM18 showed a direct promotion effect on shoot growth, when plants were inoculated with mycelium and supernatant together. Streptomyces strain MM40 and Actinoplanes strain ME3 promoted the actinorhizal symbiosis with Frankia and consequently the development of plant shoots, when supernatant was involved as inoculum. It is supposed, that the strains MM18, MM40 and ME3 produce bioactive metabolites, which are released into the culture medium. The saprophytic strains studied could be considered as "promoting or helper rhizoactinomycetes" of the actinorhizal plant D. trinervis.

  6. Actinokineospora mzabensis sp. nov., a novel actinomycete isolated from Saharan soil.

    PubMed

    Aouiche, Adel; Bouras, Noureddine; Mokrane, Salim; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2015-01-01

    A novel actinomycete strain, designated PAL84, was isolated from a Saharan soil sample collected from Béni-Isguen, Ghardaïa (South of Algeria). This strain was studied for its taxonomic position using a polyphasic approach and was identified as a member of the genus Actinokineospora. Phylogenetic analysis showed that strain PAL84 had 16S rRNA gene sequence similarities with members of the genus Actinokineospora ranging from 96.2 % (Actinokineospora inagensis DSM 44258(T)) to 97.8 % (Actinokineospora baliensis NBRC 104211(T)). The strain was observed to produce pinkish-purple aerial mycelium and purplish red substrate mycelium, which fragmented readily into chains of non-motile elements. The optimum growth temperature and pH were found to be 25-30 °C and 5.0-7.0, respectively. The cell-wall hydrolysate of strain PAL84 was found to contain meso-diaminopimelic acid and the diagnostic whole-cell sugars were identified as arabinose and galactose. The predominant menaquinone was identified as MK-9 (H4). The major fatty acids were found to be iso-C16:0, iso-C15:0, iso-C16:1 H and iso-C16:0 2OH. The diagnostic phospholipid detected was phosphatidylethanolamine. The genotypic and phenotypic data show that the strain represents a novel species of the genus Actinokineospora, for which the name Actinokineospora mzabensis sp. nov. is proposed, with the type strain PAL84(T) (=DSM 45961(T) = CECT 8578(T)).

  7. Actinopolyspora biskrensis sp. nov., a novel halophilic actinomycete isolated from Northern Sahara.

    PubMed

    Saker, Rafika; Bouras, Noureddine; Meklat, Atika; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2015-03-01

    A novel halophilic, filamentous actinomycete, designated H254(T), was isolated from a Saharan soil sample collected from Biskra (Northern Sahara), and subjected to a polyphasic taxonomic characterization. The strain is Gram-positive, aerobic, and halophilic, and the optimum NaCl concentration for growth is 15-20 % (w/v). The cell-wall hydrolysate contained meso-diaminopimelic acid, and the diagnostic whole-cell sugars were arabinose and galactose. The diagnostic phospholipid detected was phosphatidylcholine, and MK-9(H4) was the predominant menaquinone. The major fatty acid profiles were anteiso-C17:0 (32.8 %), C15:0 (28 %), and iso-C17:0 (12.3 %). Comparative analysis of the 16S rRNA gene sequences revealed that the strain H254(T) formed a well-separated sub-branch within the radiation of the genus Actinopolyspora, and the microorganism was most closely related to Actinopolyspora saharensis DSM 45459(T) (99.2 %), Actinopolyspora halophila DSM 43834(T) (99.1 %), and Actinopolyspora algeriensis DSM 45476(T) (99.0 %). Nevertheless, the strain had relatively lower mean values for DNA-DNA relatedness with the above strains (57.2, 68.4, and 45.6 %, respectively). Based on phenotypic features and phylogenetic position, we propose that strain H254(T) represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora biskrensis sp. nov. is proposed. The type strain of A. biskrensis is strain H254(T) (=DSM 46684(T) =CECT 8576(T)).

  8. Sphaerisporangium dianthi sp. nov., an endophytic actinomycete isolated from a root of Dianthus chinensis L.

    PubMed

    Xing, Jia; Liu, Chongxi; Zhang, Yuejing; He, Hairong; Zhou, Ying; Li, Lianjie; Zhao, Junwei; Liu, Shuanghe; Wang, Xiangjing; Xiang, Wensheng

    2015-01-01

    A novel actinomycete, designated strain NEAU-CY18(T), was isolated from the root of a Chinese medicinal plant Dianthus chinensis L and subjected to a polyphasic taxonomic study. The novel strain was found to develop spherical sporangia with non-motile spores on aerial mycelium. The cell-wall peptidoglycan was found to contain meso-diaminopimelic acid. The whole-cell sugars were identified as madurose, mannose, ribose, galactose and glucose. The phospholipid profile was found to contain diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylmethylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified phospholipid. The predominant menaquinones were identified as MK-9(H4), MK-9(H2) and MK-9(H6). The major fatty acids were identified as C17:0 10-methyl, iso-C16:0 and C16:0. EzTaxon-e analysis of the 16S rRNA gene sequence indicated that the strain belongs to the genus Sphaerisporangium and was most closely related to Sphaerisporangium cinnabarinum JCM 3291(T) (98.9 %) and Sphaerisporangium melleum JCM 13064(T) (98.3 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-CY18(T) forms a monophyletic clade with S. cinnabarinum JCM 3291(T), an association that was supported by a bootstrap value of 97 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. Comparisons of some phenotypic properties and low DNA-DNA relatedness values enabled the strain to be differentiated from S. cinnabarinum JCM 3291(T) and S. melleum JCM 13064(T). Therefore, it is concluded that strain NEAU-CY18(T) represents a novel Sphaerisporangium species, for which the name Sphaerisporangium dianthi sp. nov. is proposed. The type strain is NEAU-CY18(T) ( = CGMCC 4.7132(T) = DSM 46736(T)).

  9. Pseudonocardia hispaniensis sp. nov., a novel actinomycete isolated from industrial wastewater activated sludge.

    PubMed

    Cuesta, G; Soler, A; Alonso, J L; Ruvira, M A; Lucena, T; Arahal, D R; Goodfellow, M

    2013-01-01

    A novel actinomycete, designated PA3(T), was isolated from an oil refinery wastewater treatment plant, located in Palos de la Frontera, Huelva, Spain, and characterized taxonomically by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate formed a distinct subclade in the Pseudonocardia tree together with Pseudonocardia asaccharolytica DSM 44247(T). The chemotaxonomic properties of the isolate, for example, the presence of MK-8 (H(4)) as the predominant menaquinone and iso-C(16:0) as the major fatty acid, are consistent with its classification in the genus Pseudonocardia. DNA:DNA pairing experiments between the isolate and the type strain of P. asaccharolytica DSM 44247(T) showed that they belonged to separate genomic species. The two strains were readily distinguished using a combination of phenotypic properties. Consequently, it is proposed that isolate PA3(T) represents a novel species for which the name Pseudonocardia hispaniensis sp. nov. is proposed. The type strain is PA3(T) (= CCM 8391(T) = CECT 8030(T)).

  10. Glycomyces tarimensis sp. nov., an actinomycete isolated from a saline-alkali habitat.

    PubMed

    Lv, Ling-Ling; Zhang, Yue-Feng; Zhang, Li-Li

    2015-05-01

    A novel actinomycete strain, designated TRM 45387(T), was isolated from a saline-alkali soil in Xinjiang Province (40° 22' N 79° 08' E), north-west China. The isolate was characterized using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain TRM 45387(T) belonged to the genus Glycomyces and was closely related to Glycomyces arizonensis DSM 44726(T) (96.59% 16S rRNA gene sequence similarity). The G+C content of the DNA was 71.26 mol%. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid, and xylose, glucose, galactose, arabinose and ribose as the major whole-cell sugars. The diagnostic phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositolmannosides. The predominant menaquinone was MK-10(H6). The major fatty acids were iso-C16 : 0, anteiso-C17 : 0 and anteiso-C15 : 0. On the basis of the evidence from this polyphasic study, a novel species, Glycomyces tarimensis sp. nov., is proposed. The type strain of Glycomyces tarimensis is TRM 45387(T) ( =CCTCC AA 2014007(T) =JCM 30184(T)).

  11. High Sensitivity MEMS Strain Sensor: Design and Simulation

    PubMed Central

    Mohammed, Ahmed A. S.; Moussa, Walied A.; Lou, Edmond

    2008-01-01

    In this article, we report on the new design of a miniaturized strain microsensor. The proposed sensor utilizes the piezoresistive properties of doped single crystal silicon. Employing the Micro Electro Mechanical Systems (MEMS) technology, high sensor sensitivities and resolutions have been achieved. The current sensor design employs different levels of signal amplifications. These amplifications include geometric, material and electronic levels. The sensor and the electronic circuits can be integrated on a single chip, and packaged as a small functional unit. The sensor converts input strain to resistance change, which can be transformed to bridge imbalance voltage. An analog output that demonstrates high sensitivity (0.03mV/με), high absolute resolution (1με) and low power consumption (100μA) with a maximum range of ±4000με has been reported. These performance characteristics have been achieved with high signal stability over a wide temperature range (±50°C), which introduces the proposed MEMS strain sensor as a strong candidate for wireless strain sensing applications under harsh environmental conditions. Moreover, this sensor has been designed, verified and can be easily modified to measure other values such as force, torque…etc. In this work, the sensor design is achieved using Finite Element Method (FEM) with the application of the piezoresistivity theory. This design process and the microfabrication process flow to prototype the design have been presented. PMID:27879841

  12. Biodiversity, Anti-Trypanosomal Activity Screening, and Metabolomic Profiling of Actinomycetes Isolated from Mediterranean Sponges

    PubMed Central

    Cheng, Cheng; MacIntyre, Lynsey; Abdelmohsen, Usama Ramadan; Horn, Hannes; Polymenakou, Paraskevi N.; Edrada-Ebel, RuAngelie; Hentschel, Ute

    2015-01-01

    Marine sponge–associated actinomycetes are considered as promising sources for the discovery of novel biologically active compounds. In the present study, a total of 64 actinomycetes were isolated from 12 different marine sponge species that had been collected offshore the islands of Milos and Crete, Greece, eastern Mediterranean. The isolates were affiliated to 23 genera representing 8 different suborders based on nearly full length 16S rRNA gene sequencing. Four putatively novel species belonging to genera Geodermatophilus, Microlunatus, Rhodococcus and Actinomycetospora were identified based on a 16S rRNA gene sequence similarity of < 98.5% to currently described strains. Eight actinomycete isolates showed bioactivities against Trypanosma brucei brucei TC221 with half maximal inhibitory concentration (IC50) values <20 μg/mL. Thirty four isolates from the Milos collection and 12 isolates from the Crete collection were subjected to metabolomic analysis using high resolution LC-MS and NMR for dereplication purposes. Two isolates belonging to the genera Streptomyces (SBT348) and Micromonospora (SBT687) were prioritized based on their distinct chemistry profiles as well as their anti-trypanosomal activities. These findings demonstrated the feasibility and efficacy of utilizing metabolomics tools to prioritize chemically unique strains from microorganism collections and further highlight sponges as rich source for novel and bioactive actinomycetes. PMID:26407167

  13. Biodiversity, Anti-Trypanosomal Activity Screening, and Metabolomic Profiling of Actinomycetes Isolated from Mediterranean Sponges.

    PubMed

    Cheng, Cheng; MacIntyre, Lynsey; Abdelmohsen, Usama Ramadan; Horn, Hannes; Polymenakou, Paraskevi N; Edrada-Ebel, RuAngelie; Hentschel, Ute

    2015-01-01

    Marine sponge-associated actinomycetes are considered as promising sources for the discovery of novel biologically active compounds. In the present study, a total of 64 actinomycetes were isolated from 12 different marine sponge species that had been collected offshore the islands of Milos and Crete, Greece, eastern Mediterranean. The isolates were affiliated to 23 genera representing 8 different suborders based on nearly full length 16S rRNA gene sequencing. Four putatively novel species belonging to genera Geodermatophilus, Microlunatus, Rhodococcus and Actinomycetospora were identified based on a 16S rRNA gene sequence similarity of < 98.5% to currently described strains. Eight actinomycete isolates showed bioactivities against Trypanosma brucei brucei TC221 with half maximal inhibitory concentration (IC50) values <20 μg/mL. Thirty four isolates from the Milos collection and 12 isolates from the Crete collection were subjected to metabolomic analysis using high resolution LC-MS and NMR for dereplication purposes. Two isolates belonging to the genera Streptomyces (SBT348) and Micromonospora (SBT687) were prioritized based on their distinct chemistry profiles as well as their anti-trypanosomal activities. These findings demonstrated the feasibility and efficacy of utilizing metabolomics tools to prioritize chemically unique strains from microorganism collections and further highlight sponges as rich source for novel and bioactive actinomycetes.

  14. Nonomuraea monospora sp. nov., an actinomycete isolated from cave soil in Thailand, and emended description of the genus Nonomuraea.

    PubMed

    Nakaew, Nareeluk; Sungthong, Rungroch; Yokota, Akira; Lumyong, Saisamorn

    2012-12-01

    A novel actinomycete, designated strain PT708(T), was isolated from cave soil collected in Pha Tup Cave Forest Park, Nan province, Thailand. It produced compounds with antimicrobial and anticancer activities. Its chemotaxonomic properties were consistent with those of members of the genus Nonomuraea. The major menaquinone was MK-9(H(4)), with minor amounts of MK-9(H(6)), MK-9(H(2)), MK-10(H(2)) and MK-8(H(4)). The polar lipid profile contained phosphatidylmonomethylethanolamine, diphosphatidylglycerol, hydroxy-phosphatidylmonomethylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannoside and phosphatidylinositol. The major fatty acids were iso-C(16:0), 10-methyl C(17:0), C(16:0) and C(17:1)ω6c. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain PT708(T) belonged to the genus Nonomuraea and was most closely related to Nonomuraea rhizophila YIM 67092(T) (98.50% sequence similarity) and Nonomuraea rosea GW 12687(T) (98.30%). The genomic DNA G+C content of strain PT708(T) was 73.3 mol%. Unlike the recognized members of the genus Nonomuraea, the novel strain formed single spores at the tips of aerial hyphae. Based on the phenotypic, phylogenetic and genotypic evidence, strain PT708(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea monospora sp. nov. is proposed. The type strain is PT708(T) ( = TISTR 1910(T) = JCM 16114(T)).

  15. Biodiversity of Actinomycetes associated with Caribbean sponges and their potential for natural product discovery.

    PubMed

    Vicente, Jan; Stewart, Allison; Song, Bongkeun; Hill, Russell T; Wright, Jeffrey L

    2013-08-01

    Marine actinomycetes provide a rich source of structurally unique and bioactive secondary metabolites. Numerous genera of marine actinomycetes have been isolated from marine sediments as well as several sponge species. In this study, 16 different species of Caribbean sponges were collected from four different locations in the coastal waters off Puerto Rico in order to examine diversity and bioactive metabolite production of marine actinomycetes in Caribbean sponges. Sediments were also collected from each location, in order to compare actinomycete communities between these two types of samples. A total of 180 actinomycetes were isolated and identified based on 16S rRNA gene analysis. Phylogenetic analysis revealed the presence of at least 14 new phylotypes belonging to the genera Micromonospora, Verruscosispora, Streptomyces, Salinospora, Solwaraspora, Microbacterium and Cellulosimicrobium. Seventy-eight of the isolates (19 from sediments and 59 from sponges) shared 100 % sequence identity with Micromonospora sp. R1. Despite having identical 16S rRNA sequences, the bioactivity of extracts and subsequent fractions generated from the fermentation of both sponge- and sediment-derived isolates identical to Micromonospora sp. R1 varied greatly, with a marked increase in antibiotic metabolite production in those isolates derived from sponges. These results indicate that the chemical profiles of isolates with high 16S rRNA sequence homology to known strains can be diverse and dependent on the source of isolation. In addition, seven previously reported dihydroquinones produced by five different Streptomyces strains have been purified and characterized from one Streptomyces sp. strain isolated in this study from the Caribbean sponge Agelas sceptrum.

  16. Micromonospora zeae sp. nov., a novel endophytic actinomycete isolated from corn root (Zea mays L.).

    PubMed

    Shen, Yue; Zhang, Yuejing; Liu, Chongxi; Wang, Xiangjing; Zhao, Junwei; Jia, Feiyu; Yang, Lingyu; Yang, Deguang; Xiang, Wensheng

    2014-11-01

    A novel actinomycete, designated strain NEAU-gq9(T), was isolated from corn root (Zea mays L.) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora. On the basis of 16S rRNA gene sequence similarity studies, strain NEAU-gq9(T) was most closely related to Micromonospora zamorensis CR38(T) (99.3%), Micromonospora jinlongensis NEAU-GRX11(T) (99.2%), Micromonospora saelicesensis Lupac 09(T) (99.2%), Micromonospora chokoriensis 2-19(6)(T) (98.9%), Micromonospora coxensis 2-30-b(28)(T) (98.6%) and Micromonospora lupini Lupac 14N(T) (98.5%). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that strain NEAU-gq9(T) is a member of the genus Micromonospora and supported the closest phylogenetic relationship to M. zamorensis CR38(T), M. jinlongensis NEAU-GRX11(T), M. saelicesensis Lupac 09(T), M. chokoriensis 2-19(6)(T) and M. lupini Lupac 14N(T). A combination of DNA-DNA hybridization, morphological and physiological characteristics indicated that the novel strain could be readily distinguished from the closest phylogenetic relatives. Therefore, it is proposed that strain NEAU-gq9(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora zeae sp. nov. is proposed. The type strain is NEAU-gq9(T) (=CGMCC 4.7092(T)=DSM 45882(T)).

  17. Saccharopolyspora griseoalba sp. nov., a novel actinomycete isolated from the Dead Sea.

    PubMed

    Jiang, Yingying; Wei, Xiaomin; Chen, Xiu; Jiang, Yi; Xue, Quanhong; Lai, Hangxian; Jiang, Chenglin

    2016-12-01

    A novel halotolerant actinomycete, designated strain AFM 10238(T), was isolated from a sediment sample collected from the Dead Sea of Israel. The isolate grew at 15-45 °C, pH 6-12 and with 0-15 % (w/v) NaCl. Strain AFM 10238(T) contains meso-diaminopimelic acid as cell wall diamino acid, and galactose and arabinose as the whole cell sugars. The major polar lipids are phosphatidylcholine, phosphatidylglycerol, and diphosphatidylglycerol. Major fatty acids are iso-C16:0, iso-C17:0, iso-C15:0, anteiso-C17:0 and C17:1 ω8c. MK-9(H4) is the predominant menaquinone and the DNA G + C content is 72.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AFM10238(T) belongs to the genus Saccharopolyspora. The 16S rRNA gene sequence similarity between strain AFM 10238(T) and its close neighbours, Saccharopolyspora halophila YIM 90500(T) , Saccharopolyspora spinosa DSM 44228(T), Saccharopolyspora dendranthemae KLBMP 1305(T) and Saccharopolyspora cebuensis DSM 45019(T) were 98.2, 97.2, 97.1 and 97.0 %, respectively. Sequence similarities to other type strains of this genus were below 97 %. DNA-DNA relatedness data, together with phenotypic and chemotaxonomic differences, clearly distinguished the isolate from its close neighbours. On the basis of the data from this polyphasic analysis, a novel species Saccharopolyspora griseoalba sp. nov. is proposed. The type strain is AFM 10238(T) (= DSM 46,663 = CGMCC 4.7124).

  18. Plantactinosporasoyae sp. nov., an endophytic actinomycete isolated from soybean root [Glycine max (L.) Merr].

    PubMed

    Guo, Xiaowei; Guan, Xuejiao; Liu, Chongxi; Jia, Feiyu; Li, Jiansong; Li, Jinmeng; Jin, Pinjiao; Li, Wenchao; Wang, Xiangjing; Xiang, Wensheng

    2016-07-01

    A novel actinomycete, designated strain NEAU-gxj3T, was isolated from soybean root [Glycine max (L.) Merr.] collected from Harbin, Heilongjiang Province, China, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain NEAU-gxj3T showed highest similarity to those of Micromonospora equina Y22T (98.2 %) and Plantactinospora endophytica YIM 68255T (98.0 %). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that the isolate clustered with the members of the genus Plantactinospora. The chemotaxonomic properties of strain NEAU-gxj3Twere also consistent with those of members of the genus Plantactinospora. The cell wall contained meso-diaminopimelic acid and whole-cell sugars were xylose, glucose and galactose. The predominant menaquinones were MK-10(H6), MK-9(H8), MK-10(H2) and MK-10(H4). The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were identified as anteiso-C17 : 0, iso-C16 : 0, iso-C15 : 0 and C15 : 0. A combination of DNA-DNA hybridization result and some phenotypic characteristics indicated that strain NEAU-gxj3Tcould be differentiated clearly from its closest phylogenetic relatives. Therefore, the strain is concluded to represent a novel species of the genus Plantactinospora, for which the name Plantactinospora soyae sp. nov. is proposed. The type strain is NEAU-gxj3T (=CGMCC 4.7221T=DSM 46832T).

  19. Inhibition of norsolorinic acid accumulation to Aspergillus parasiticus by marine actinomycetes

    NASA Astrophysics Data System (ADS)

    Yan, Peisheng; Shi, Cuijuan; Shen, Jihong; Wang, Kai; Gao, Xiujun; Li, Ping

    2014-11-01

    Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods. Among them, three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp. by 16S rRNA gene sequencing analysis. The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate, and the activities of the extracts were determined by tip culture assay. The assay results show that both extracts inhibited mycelium growth and toxin production, and the inhibitory activities of the extracts increased as their concentrations increased. The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins, and that these bacteria could be used as novel biopesticides against mycotoxins.

  20. Streptomyces luozhongensis sp. nov., a novel actinomycete with antifungal activity and antibacterial activity.

    PubMed

    Zhang, Renwen; Han, Xiaoxue; Xia, Zhanfeng; Luo, Xiaoxia; Wan, Chuanxing; Zhang, Lili

    2017-02-01

    A novel actinomycete strain, designated TRM 49605(T), was isolated from a desert soil sample from Lop Nur, Xinjiang, north-west China, and characterised using a polyphasic taxonomic approach. The strain exhibited antifungal activity against the following strains: Saccharomyces cerevisiae, Curvularia lunata, Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, Penicillium citrinum, Candida albicans and Candida tropicalis; Antibacterial activity against Bacillus subtilis, Staphylococcus epidermidis and Micrococcus luteus; and no antibacterial activity against Escherichia coli. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain TRM 49605(T) to the genus Streptomyces. Strain TRM 49605(T) shows high sequence similarities to Streptomyces roseolilacinus NBRC 12815(T) (98.62 %), Streptomyces flavovariabilis NRRL B-16367(T) (98.45 %) and Streptomyces variegatus NRRL B-16380(T) (98.45 %). Whole cell hydrolysates of strain TRM 49605(T) were found to contain LL-diaminopimelic acid as the diagnostic diamino acid and galactose, glucose, xylose and mannose as the major whole cell sugars. The major fatty acids in strain TRM 49605(T) were identified as iso C16:0, anteiso C15:0, C16:0 and Summed Feature 5 as defined by MIDI. The main menaquinones were identified as MK-9(H4), MK-9(H6), MK-9(H8) and MK-10(H6). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and phosphatidylinositol mannoside. The G+C content of the genomic DNA was determined to be 71.2 %. The DNA-DNA relatedness between strain TRM 49605(T) and the phylogenetically related strain S. roseolilacinus NBRC 12815(T) was 60.12 ± 0.06 %, which is lower than the 70 % threshold value for delineation of genomic prokaryotic species. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain TRM 49605(T) (=CCTCC AA2015026(T) = KCTC 39666(T)) should be designated as the type strain of a novel species of the genus

  1. Biosynthetic Potential of Phylogenetically Unique Endophytic Actinomycetes from Tropical Plants▿ †

    PubMed Central

    Janso, Jeffrey E.; Carter, Guy T.

    2010-01-01

    The culturable diversity of endophytic actinomycetes associated with tropical, native plants is essentially unexplored. In this study, 123 endophytic actinomycetes were isolated from tropical plants collected from several locations in Papua New Guinea and Mborokua Island, Solomon Islands. Isolates were found to be prevalent in roots but uncommon in leaves. Initially, isolates were dereplicated to the strain level by ribotyping. Subsequent characterization of 105 unique strains by 16S rRNA gene sequence analysis revealed that 17 different genera were represented, and rare genera, such as Sphaerisporangium and Planotetraspora, which have never been previously reported to be endophytic, were quite prevalent. Phylogenetic analyses grouped many of the strains into clades distinct from known genera within Thermomonosporaceae and Micromonosporaceae, indicating that they may be unique genera. Bioactivity testing and liquid chromatography-mass spectrometry (LC-MS) profiling of crude fermentation extracts were performed on 91 strains. About 60% of the extracts exhibited bioactivity or displayed LC-MS profiles with spectra indicative of secondary metabolites. The biosynthetic potential of 29 nonproductive strains was further investigated by the detection of putative polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes. Despite their lack of detectable secondary metabolite production in fermentation, most were positive for type I (66%) and type II (79%) PKS genes, and all were positive for NRPS genes. These results suggest that tropical plants from New Guinea and the adjacent archipelago are hosts to unique endophytic actinomycetes that possess significant biosynthetic potential. PMID:20472734

  2. Marine actinomycete diversity and natural product discovery.

    PubMed

    Jensen, Paul R; Mincer, Tracy J; Williams, Philip G; Fenical, William

    2005-01-01

    Microbial natural products remain an important resource for drug discovery yet the microorganisms inhabiting the world's oceans have largely been overlooked in this regard. The recent discovery of novel secondary metabolites from taxonomically unique populations of marine actinomycetes suggests that these bacteria add an important new dimension to microbial natural product research. Continued efforts to characterize marine actinomycete diversity and how adaptations to the marine environment affect secondary metabolite production will create a better understanding of the potential utility of these bacteria as a source of useful products for biotechnology.

  3. Metabolite generation via microbial biotransformations with Actinomycetes: rapid screening for active strains and biosynthesis of important human metabolites of two development-stage compounds, 5-[(5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]non7-yl-methyl]-3-thiophenecarboxylic acid (BMS-587101) and dasatinib.

    PubMed

    Li, Wenying; Josephs, Jonathan L; Skiles, Gary L; Humphreys, W Griffith

    2008-04-01

    The enzymes present in many microbial strains are capable of carrying out a variety of biotransformations when presented with drug-like molecules. Although the enzymes responsible for the biotransformations are not well characterized, microbial strains can often be found that produce metabolites identical to those found in mammalian systems. However, traditional screening for microbial strains that produce metabolites of interest is done with many labor intensive steps that include multiple shake flasks and many manual manipulations, which hinder the application of these techniques in drug metabolite preparation. A 24-well microtiter plate screening system was developed for rapid screening of actinomycetes strains for their ability to selectively produce metabolites of interest. The utility of this system was first demonstrated with the well characterized cytochrome P450 substrate diclofenac. Subsequently, the use of this system allowed the rapid identification of several actinomycetes strains that were capable of converting two drug candidates under development, 5-[(5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]non7-yl-methyl]-3-thiophenecarboxylic acid and N-(2-chloro-6-methylphenyl)-2-[[6-[4-(2-hydroxyethyl)-1-piperazinyl)]-2-methyl-4-pyrimidinyl]amino)]-1,3-thiazole-5-carboxamide (dasatinib, Sprycel, BMS-345825), to mammalian metabolites of interest. Milligram quantities of the metabolites were then prepared by scaling-up the microbial biotransformation reactions. These quantities were sufficient for initial characterization, such as testing for pharmacological activity and use as analytical standards, prior to the availability of authentic chemically synthesized compounds.

  4. Actinomycetospora rhizophila sp. nov., an actinomycete isolated from rhizosphere soil of a peace lily (Spathi phyllum Kochii).

    PubMed

    He, Hairong; Zhang, Yuejing; Ma, Zhaoxu; Li, Chuang; Liu, Chongxi; Zhou, Ying; Li, Lianjie; Wang, Xiangjing; Xiang, Wensheng

    2015-05-01

    A novel actinomycete, designated strain NEAU-B-8(T), was isolated from the rhizosphere soil of a peace lily (Spathi phyllum Kochii) collected from Heilongjiang province, north-east China. Key morphological and physiological characteristics as well as chemotaxonomic features of strain NEAU-B-8(T) were congruent with the description of the genus Actinomycetospora , such as the major fatty acids, the whole-cell hydrolysates, the predominant menaquinone and the phospholipid profile. The 16S rRNA gene sequence analysis revealed that strain NEAU-B-8(T) shared the highest sequence similarities with Actinomycetospora lutea JCM 17982(T) (99.3% 16S rRNA gene sequence similarity), Actinomycetospora chlora TT07I-57(T) (98.4 %), Actinomycetospora straminea IY07-55(T) (98.3%) and Actinomycetospora chibensis TT04-21(T) (98.2%); similarities to type strains of other species of this genus were lower than 98%. The phylogenetic tree based on 16S rRNA gene sequences showed that strain NEAU-B-8(T) formed a distinct branch with A. lutea JCM 17982(T) that was supported by a high bootstrap value of 97% in the neighbour-joining tree and was also recovered with the maximum-likelihood algorithm. However, the DNA-DNA relatedness between strain NEAU-B-8(T) and A. lutea JCM 17982(T) was found to be 50.6 ± 1.2%. Meanwhile, strain NEAU-B-8(T) differs from other most closely related strains in phenotypic properties, such as maximum NaCl tolerance, hydrolysis of aesculin and decomposition of urea. On the basis of the morphological, physiological, chemotaxonomic, phylogenetic and DNA-DNA hybridization data, we conclude that strain NEAU-B-8(T) represents a novel species of the genus Actinomycetospora , named Actinomycetospora rhizophila sp. nov. The type strain is NEAU-B-8(T). ( = CGMCC 4.7134(T) =DSM 46673(T)).

  5. Protein design in systems metabolic engineering for industrial strain development.

    PubMed

    Chen, Zhen; Zeng, An-Ping

    2013-05-01

    Accelerating the process of industrial bacterial host strain development, aimed at increasing productivity, generating new bio-products or utilizing alternative feedstocks, requires the integration of complementary approaches to manipulate cellular metabolism and regulatory networks. Systems metabolic engineering extends the concept of classical metabolic engineering to the systems level by incorporating the techniques used in systems biology and synthetic biology, and offers a framework for the development of the next generation of industrial strains. As one of the most useful tools of systems metabolic engineering, protein design allows us to design and optimize cellular metabolism at a molecular level. Here, we review the current strategies of protein design for engineering cellular synthetic pathways, metabolic control systems and signaling pathways, and highlight the challenges of this subfield within the context of systems metabolic engineering.

  6. Culturable rare Actinomycetes: diversity, isolation and marine natural product discovery.

    PubMed

    Subramani, Ramesh; Aalbersberg, William

    2013-11-01

    Rare Actinomycetes from underexplored marine environments are targeted in drug discovery studies due to the Actinomycetes' potentially huge resource of structurally diverse natural products with unusual biological activity. Of all marine bacteria, 10 % are Actinomycetes, which have proven an outstanding and fascinating resource for new and potent bioactive molecules. Past and present efforts in the isolation of rare Actinomycetes from underexplored diverse natural habitats have resulted in the isolation of about 220 rare Actinomycete genera of which more than 50 taxa have been reported to be the producers of 2,500 bioactive compounds. That amount represents greater than 25 % of the total Actinomycetes metabolites, demonstrating that selective isolation methods are being developed and extensively applied. Due to the high rediscovery rate of known compounds from Actinomycetes, a renewed interest in the development of new antimicrobial agents from rare and novel Actinomycetes is urgently required to combat the increasing number of multidrug-resistant human pathogens. To facilitate that discovery, this review updates all selective isolation media including pretreatment and enrichment methods for the isolation of marine rare Actinomycetes. In addition, this review demonstrates that discovering new compounds with novel scaffolds can be increased by intensive efforts in isolating and screening rare marine genera of Actinomycetes. Between 2007 and mid-2013, 80 new rare Actinomycete species were reported from marine habitats. They belong to 23 rare families, of which three are novel, and 20 novel genera. Of them, the family Micromonosporaceae is dominant as a producer of promising chemical diversity.

  7. Actinomycetes in the rhizosphere of semidesert soils of Mongolia

    NASA Astrophysics Data System (ADS)

    Norovsuren, Zh.; Zenova, G. M.; Mosina, L. V.

    2007-04-01

    The population density of actinomycetes in the desert-steppe soil, rhizosphere, and the above-ground parts of plants varies from tens to hundreds of thousands of colony-forming units (CFU) per gram of substrate. The actinomycetal complexes of the brown desert-steppe soil without plant roots are more diverse in their taxonomic composition than the actinomycetal complexes in the rhizosphere and the aboveground parts of plants. Additionally to representatives of the Streptomyces and Micromonospora genera, actinomycetes from the Nocardia, Saccharopolyspora, Thermomonospora, and Actinomadura genera were identified in the soil. The population density of actinomycetes in the rhizosphere and in the soil reached hundreds of thousand CFU/g; it considerably exceeded the population density of actinomycetes in the aboveground parts of plants. The maximum population density of actinomycetes was determined in the rhizosphere of Asparagus gobicus, Salsola pestifera, and Cleistogenes songorica.

  8. Systematic and biotechnological aspects of halophilic and halotolerant actinomycetes.

    PubMed

    Hamedi, Javad; Mohammadipanah, Fatemeh; Ventosa, Antonio

    2013-01-01

    More than 70 species of halotolerant and halophilic actinomycetes belonging to at least 24 genera have been validly described. Halophilic actinomycetes are a less explored source of actinomycetes for discovery of novel bioactive secondary metabolites. Degradation of aliphatic and aromatic organic compounds, detoxification of pollutants, production of new enzymes and other metabolites such as antibiotics, compatible solutes and polymers are other potential industrial applications of halophilic and halotolerant actinomycetes. Especially new bioactive secondary metabolites that are derived from only a small fraction of the investigated halophilic actinomycetes, mainly from marine habitats, have revealed the huge capacity of this physiological group in production of new bioactive chemical entities. Combined high metabolic capacities of actinomycetes and unique features related to extremophilic nature of the halophilic actinomycetes have conferred on them an influential role for future biotechnological applications.

  9. Amycolatopsis flava sp. nov., a halophilic actinomycete isolated from Dead Sea.

    PubMed

    Wei, Xiaomin; Jiang, Yingying; Chen, Xiu; Jiang, Yi; Lai, Hangxian

    2015-10-01

    A novel halophilic, filamentous actinomycete, designated strain AFM 10111(T), was isolated from a sediment sample collected from the Dead Sea of Israel and its taxonomic position was established by using a polyphasic taxonomic approach. The isolate grew at 20-35 °C, pH 5-12 and with 1-30 % NaCl. The substrate mycelium is white or yellow, well developed, branched and fragments into squarish, rod-like elements. The isolate contained meso-diaminopimelic acid as cell-wall diamino acid, and arabinose and galactose as whole-cell sugars. The major menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine phosphatidylmethylethanolamine and one unidentified phospholipid. Major fatty acids were iso-C16:0, iso-C16:1 H, C17:1 ω6c. The DNA G + C content was 67.7 mol %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AFM 10111(T) belongs to the genus Amycolatopsis, and formed a distinct clade with Amycolatopsis marina CGMCC 4.3568(T) and Amycolatopsis palatopharyngis CGMCC 4.1729(T), with the sequence similarity 98.4 and 98.6 %. The level of DNA-DNA relatedness between the strain AFM 10111(T) and A. marina CGMCC 4.3568(T) and A. palatopharyngis CGMCC 4.1729(T) were 46.9 ± 3.08 and 49.4 ± 1.25 %. The combined genotypic and phenotypic data indicate that strain AFM 10111(T) represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis flava sp. nov. is proposed. The type strain is AFM 10111(T) (= DSM 46658(T) = CGMCC 4.7123(T)).

  10. Actinomycetes from solitary wasp mud nest and swallow bird mud nest: isolation and screening for their antibacterial activity.

    PubMed

    Kumar, Vijay; Bharti, Alpana; Gupta, Vivek Kumar; Gusain, Omprakash; Bisht, Gajraj Singh

    2012-03-01

    The aim of this study was to isolate and screen actinomycetes from solitary wasp and swallow bird mud nests for antimicrobial activity. The actinomycetes were isolated from soil of nests of solitary wasp and swallow bird, and identified on the basis of morphological characteristics and molecular biological methods. A total of 109 actinomycetal isolates were obtained from 12 soil samples (6 from each habitat) using two media. The highest number of actinomycetes were recovered on Humic acid vitamin agar media (65.13%, n = 71) as compared to actinomycetes isolation agar media (34.86%, n = 38). The antimicrobial activity of actinomycetes isolates was determined using the agar plug method. Among 109 isolates, 51 isolates (46.78%) showed antibacterial activity by agar plug assay. The morphological and molecular characteristics confirmed that the most of active isolates in both sample belonged to the genus Streptomyces, the other potential genera like Streptosporangium, Actinomadura, Saccharopolyspora, Thermoactinomycetes and Nocardia were also recovered, but in a low frequency. The isolates designated as 8(1), BN-6, MN 2(6), MN 2(7) and MN 9(V) showed most promising activity against various drug resistant bacterial pathogens. It seems that the promising isolates from these unusual/unexplored habitats may prove to be an important step in development of drug for treating multi-drug resistant bacterial pathogens.

  11. [Coculture of actinomycetes with Bacillus subtilis and its effect on the bioactive secondary metabolites].

    PubMed

    Huang, Bing; Liu, Ning; Huang, Ying; Chen, Jinchun

    2009-06-01

    To explore the effect of coculturing actinomycetes with Bacillus subtilis on the production of bioactive secondary metabolites, we studied the difference between fermentation products of monocultures and the corresponding cocultures of 22 actinomycetes by antimicrobial assay and HPLC-PDA analysis. We selected Streptomyces strain FXJ2.014 with high bioactivity for further analysis and found additional metabolites in fermentation extracts of cocultures of strains FXJ2.014, FXJ1.296 and AS 4.1252 respectively with B. subtilis. Quinomycin A was the main bioactive metabolite produced by the monoculture of strain FXJ2.014, while a new quinomycin-like component named FXJ2.014-HB was produced when strain FXJ2.014 was cocultured with B. subtilis. Further tests of antimicrobial and antitumor activities indicated that FXJ2.014-HB and Quinomycin A had significant differences in terms of bioactivity. Moreover, the inhibitory activity of FXJ2.014-HB to a variety of tumor cell lines was weaker than the highly toxic Quinomycin A, indicating its potential to be an antibiotic with low cell toxicity. In conclusion, coculture can be used as a promising approach to discover bioactive secondary metabolites from actinomycetes.

  12. Red Soils Harbor Diverse Culturable Actinomycetes That Are Promising Sources of Novel Secondary Metabolites

    PubMed Central

    Guo, Xiaoxuan; Liu, Ning; Li, Xiaomin; Ding, Yun; Shang, Fei; Gao, Yongsheng; Ruan, Jisheng

    2015-01-01

    Red soils, which are widely distributed in tropical and subtropical regions of southern China, are characterized by low organic carbon, high content of iron oxides, and acidity and, hence, are likely to be ideal habitats for acidophilic actinomycetes. However, the diversity and biosynthetic potential of actinomycetes in such habitats are underexplored. Here, a total of 600 actinomycete strains were isolated from red soils collected in Jiangxi Province in southeast China. 16S rRNA gene sequence analysis revealed a high diversity of the isolates, which were distributed into 26 genera, 10 families, and 7 orders within the class Actinobacteria; these taxa contained at least 49 phylotypes that are likely to represent new species within 15 genera. The isolates showed good physiological potentials for biosynthesis and biocontrol. Chemical screening of 107 semirandomly selected isolates spanning 20 genera revealed the presence of at least 193 secondary metabolites from 52 isolates, of which 125 compounds from 39 isolates of 12 genera were putatively novel. Macrolides, polyethers, diketopiperazines, and siderophores accounted for most of the known compounds. The structures of six novel compounds were elucidated, two of which had a unique skeleton and represented characteristic secondary metabolites of a putative novel Streptomyces phylotype. These results demonstrate that red soils are rich reservoirs for diverse culturable actinomycetes, notably members of the families Streptomycetaceae, Pseudonocardiaceae, and Streptosporangiaceae, with the capacity to synthesize novel bioactive compounds. PMID:25724963

  13. Artificial chromosomes to explore and to exploit biosynthetic capabilities of actinomycetes.

    PubMed

    Alduina, Rosa; Gallo, Giuseppe

    2012-01-01

    Actinomycetes are an important source of biologically active compounds, like antibiotics, antitumor agents, and immunosuppressors. Genome sequencing is revealing that this class of microorganisms has larger genomes relative to other bacteria and uses a considerable fraction of its coding capacity (5-10%) for the production of mostly cryptic secondary metabolites. To access actinomycetes biosynthetic capabilities or to improve the pharmacokinetic properties and production yields of these chemically complex compounds, genetic manipulation of the producer strains can be performed. Heterologous expression in amenable hosts can be useful to exploit and to explore the genetic potential of actinomycetes and not cultivable but interesting bacteria. Artificial chromosomes that can be stably integrated into the Streptomyces genome were constructed and demonstrated to be effective for transferring entire biosynthetic gene clusters from intractable actinomycetes into more suitable hosts. In this paper, the construction of several shuttle Escherichia coli-Streptomyces artificial chromosomes is discussed together with old and new strategies applied to improve heterologous production of secondary metabolites.

  14. Antimicrobial biosynthetic potential and genetic diversity of endophytic actinomycetes associated with medicinal plants.

    PubMed

    Gohain, Anwesha; Gogoi, Animesh; Debnath, Rajal; Yadav, Archana; Singh, Bhim P; Gupta, Vijai K; Sharma, Rajeev; Saikia, Ratul

    2015-10-01

    Endophytic actinomycetes are one of the primary groups that share symbiotic relationships with medicinal plants and are key reservoir of biologically active compounds. In this study, six selective medicinal plants were targeted for the first time for endophytic actinomycetes isolation from Gibbon Wild Life Sanctuary, Assam, India, during winter and summer and 76 isolates were obtained. The isolates were found to be prevalent in roots followed by stem and leaves. 16S rRNA gene sequence analysis revealed 16 genera, including rare genera, Verrucosispora, Isoptericola and Kytococcus, which have never been previously reported as endophytic. The genus Streptomyces (66%) was dominant in both seasons. Shannon's diversity index showed that Azadirachta indica (1.49), Rauwolfia serpentina (1.43) and Emblica officinalis (1.24) were relatively good habitat for endophytic actinomycetes. Antimicrobial strains showed prevalence of polyketide synthase (PKS) type-II (85%) followed by PKS type-I (14%) encoded in the genomes. Expression studies showed 12-fold upregulation of PKSII gene in seventh day of incubation for Streptomyces antibioticus (EAAG90). Our results emphasize that the actinomycetes assemblages within plant tissue exhibited biosynthetic systems encoding for important biologically active compounds.

  15. Red soils harbor diverse culturable actinomycetes that are promising sources of novel secondary metabolites.

    PubMed

    Guo, Xiaoxuan; Liu, Ning; Li, Xiaomin; Ding, Yun; Shang, Fei; Gao, Yongsheng; Ruan, Jisheng; Huang, Ying

    2015-05-01

    Red soils, which are widely distributed in tropical and subtropical regions of southern China, are characterized by low organic carbon, high content of iron oxides, and acidity and, hence, are likely to be ideal habitats for acidophilic actinomycetes. However, the diversity and biosynthetic potential of actinomycetes in such habitats are underexplored. Here, a total of 600 actinomycete strains were isolated from red soils collected in Jiangxi Province in southeast China. 16S rRNA gene sequence analysis revealed a high diversity of the isolates, which were distributed into 26 genera, 10 families, and 7 orders within the class Actinobacteria; these taxa contained at least 49 phylotypes that are likely to represent new species within 15 genera. The isolates showed good physiological potentials for biosynthesis and biocontrol. Chemical screening of 107 semirandomly selected isolates spanning 20 genera revealed the presence of at least 193 secondary metabolites from 52 isolates, of which 125 compounds from 39 isolates of 12 genera were putatively novel. Macrolides, polyethers, diketopiperazines, and siderophores accounted for most of the known compounds. The structures of six novel compounds were elucidated, two of which had a unique skeleton and represented characteristic secondary metabolites of a putative novel Streptomyces phylotype. These results demonstrate that red soils are rich reservoirs for diverse culturable actinomycetes, notably members of the families Streptomycetaceae, Pseudonocardiaceae, and Streptosporangiaceae, with the capacity to synthesize novel bioactive compounds.

  16. Actinomycetes: A Source of Lignocellulolytic Enzymes

    PubMed Central

    Saini, Anita; Aggarwal, Neeraj K.; Sharma, Anuja; Yadav, Anita

    2015-01-01

    Lignocellulose is the most abundant biomass on earth. Agricultural, forest, and agroindustrial activities generate tons of lignocellulosic wastes annually, which present readily procurable, economically affordable, and renewable feedstock for various lignocelluloses based applications. Lignocelluloses are the focus of present decade researchers globally, in an attempt to develop technologies based on natural biomass for reducing dependence on expensive and exhaustible substrates. Lignocellulolytic enzymes, that is, cellulases, hemicellulases, and lignolytic enzymes, play very important role in the processing of lignocelluloses which is prerequisite for their utilization in various processes. These enzymes are obtained from microorganisms distributed in both prokaryotic and eukaryotic domains including bacteria, fungi, and actinomycetes. Actinomycetes are an attractive microbial group for production of lignocellulose degrading enzymes. Various studies have evaluated the lignocellulose degrading ability of actinomycetes, which can be potentially implemented in the production of different value added products. This paper is an overview of the diversity of cellulolytic, hemicellulolytic, and lignolytic actinomycetes along with brief discussion of their hydrolytic enzyme systems involved in biomass modification. PMID:26793393

  17. Isolation and characterization of novel marine-derived actinomycete taxa rich in bioactive metabolites.

    PubMed

    Magarvey, Nathan A; Keller, Jessica M; Bernan, Valerie; Dworkin, Martin; Sherman, David H

    2004-12-01

    A unique selective enrichment procedure has resulted in the isolation and identification of two new genera of marine-derived actinobacteria. Approximately 90% of the microorganisms cultured by using the presented method were from the prospective new genera, a result indicative of its high selectivity. In this study, 102 actinomycetes were isolated from subtidal marine sediments collected from the Bismarck Sea and the Solomon Sea off the coast of Papua New Guinea. A combination of physiological parameters, chemotaxonomic characteristics, distinguishing 16S rRNA gene sequences, and phylogenetic analysis based on 16S rRNA genes provided strong evidence for the two new genera (represented by strains of the PNG1 clade and strain UMM518) within the family Micromonosporaceae. Biological activity testing of fermentation products from the new marine-derived actinomycetes revealed that several had activities against multidrug-resistant gram-positive pathogens, malignant cells, and vaccinia virus replication.

  18. Value of the O-nitrophenyl-beta-D-galactopyranoside test to differentiate among the aerobic actinomycetes.

    PubMed Central

    Flores, M; Ford, E G; Janda, J M

    1990-01-01

    A comparative study to determine beta-D-galactosidase activity among 171 strains of aerobic actinomycetes (including mycobacteria and rhodococci) was performed by using two growth media and four O-nitrophenyl-beta-D-galactopyranoside (ONPG) substrates. The ONPG test was found to be a valuable screening test to differentiate between the ONPG-positive Nocardia spp. and the rapidly growing ONPG-negative mycobacteria and rhodococci. However, ONPG results varied significantly depending on the growth medium and test substrate used. PMID:2121796

  19. New benzoxazine secondary metabolites from an arctic actinomycete.

    PubMed

    Moon, Kyuho; Ahn, Chan-Hong; Shin, Yoonho; Won, Tae Hyung; Ko, Keebeom; Lee, Sang Kook; Oh, Ki-Bong; Shin, Jongheon; Nam, Seung-Il; Oh, Dong-Chan

    2014-04-30

    Two new secondary metabolites, arcticoside (1) and C-1027 chromophore-V (2), were isolated along with C-1027 chromophore-III and fijiolides A and B (3-5) from a culture of an Arctic marine actinomycete Streptomyces strain. The chemical structures of 1 and 2 were elucidated through NMR, mass, UV, and IR spectroscopy. The hexose moieties in 1 were determined to be d-glucose from a combination of acid hydrolysis, derivatization, and gas chromatographic analyses. Arcticoside (1) and C-1027 chromophore-V (2), which have a benzoxazine ring, inhibited Candida albicans isocitrate lyase. Chromophore-V (2) exhibited significant cytotoxicity against breast carcinoma MDA-MB231 cells and colorectal carcinoma cells (line HCT-116), with IC₅₀ values of 0.9 and 2.7 μM, respectively.

  20. Oligotrophy is Helpful for the Isolation of Bioactive Actinomycetes.

    PubMed

    Wang, Dong-Sheng; Xue, Quan-Hong; Ma, Yun-Yan; Wei, Xiao-Li; Chen, Jie; He, Fei

    2014-06-01

    It is necessary to develop new methods for the isolation of unknown actinomycetes from soils. To evaluate the effects of oligotrophic medium on the isolation of soil actinomycetes and develop a new isolation method, the Gause's synthetic medium was diluted to one tenth the recommended concentration in the present study. Soil dilution plate technique was used to isolate actinomycetes from the soil samples. Oligotrophy decreased actinomycete and streptomycete counts, as well as the number of antagonistic actinomycete species. Oligotrophy also decreased the number of actinomycete species in five samples. Some actinomycete species were cultured only on the oligotrophic medium, whereas other species could not be cultured. Oligotrophy decreased actinomycete counts more significantly for soils with organic matter content >40 g/kg. We used 16S rRNA sequence analysis to identify 22 actinomycete species that were only cultured on the oligotrophic medium. Oligotrophic medium was helpful for the isolation of Streptomyces spp., Micromonospora spp. and Streptosporangium spp. Slightly more than 80 % of the identified actinomycete species were biologically active. Therefore, we could draw a conclusion that oligotrophic medium could be helpful for the discovery of new antibiotic producers and the exploitation and utilization of new, biologically active compounds.

  1. Glucanolytic Actinomycetes Antagonistic to Phytophthora fragariae var. rubi, the Causal Agent of Raspberry Root Rot

    PubMed Central

    Valois, D.; Fayad, K.; Barasubiye, T.; Garon, M.; Dery, C.; Brzezinski, R.; Beaulieu, C.

    1996-01-01

    A collection of about 200 actinomycete strains was screened for the ability to grow on fragmented Phytophthora mycelium and to produce metabolites that inhibit Phytophthora growth. Thirteen strains were selected, and all produced (beta)-1,3-, (beta)-1,4-, and (beta)-1,6-glucanases. These enzymes could hydrolyze glucans from Phytophthora cell walls and cause lysis of Phytophthora cells. These enzymes also degraded other glucan substrates, such as cellulose, laminarin, pustulan, and yeast cell walls. Eleven strains significantly reduced the root rot index when inoculated on raspberry plantlets. PMID:16535313

  2. Study of the effects of urban organic residues on the distribution of culturable actinomycetes in a Tunisian agricultural soil.

    PubMed

    Mokni-Tlili, Sonia; Jaoua, Leila; Murano, Fumio; Jedidi, Naceur; Hassen, Abdennaceur

    2009-05-01

    The main objective of this investigation was to identify a collection of actinomycetes isolates and to study the influence of amendment [municipal solid waste compost (MSWC) and farmyard manure (FM)] on their distribution in agricultural soil. For this purpose, a phenotypic and molecular characterization of 226 isolates collected from soil (with and without amendment) and 55 isolates from MSWC and FM was developed. The phenotypic study showed that the majority of strains isolated belong to the genus Streptomyces. By using the 16S rDNA polymerase chain reaction-restriction fragment length polymorphism method (restriction digest using six enzymes AluI, HhaI, MspI, TaqI, RsaI and HaeIII), two clusters were found: Streptomyces, dominant genus and Amycolatopsis, followed by Nocardioides. This result agreed with phylogeny revealed by 16S rDNA sequencing. The number of these actinomycetes in soil increased with FM or MSWC application. The studied soil is a potential source for isolation of actinomycetes, especially Streptomyces, and the application of organic amendment to the soil appeared to have an impact on the diversity of actinomycetes. Amendment of the soil with MSWC and FM significantly increased the number of actinomycetes due to the contribution of bacteria originally contained in biowastes and/or by stimulation of the endogenous soil micro-organisms.

  3. Isolation and characterization of Cr(VI)-reducing actinomycetes from estuarine sediments.

    PubMed

    Terahara, Takeshi; Xu, Xudan; Kobayashi, Takeshi; Imada, Chiaki

    2015-04-01

    Bioremediation technologies have strong potential use in the less costly and more environmentally friendly removal of highly toxic hexavalent-chromium (Cr(VI)) compared with physicochemical technologies. Several Cr(VI)-reducing bacteria have been isolated; however, there are few studies on Cr(VI)-resistant and Cr(VI)-reducing actinomycetes. In this study, Cr(VI)-reducing actinomycetes were screened from estuarine, marine, and terrestrial samples on the basis of Cr(VI)-resistant and Cr(VI)-reducing ability. Of the 80 Streptomyces-like strains isolated, 20 strains were found to be resistant to 50 mg/l of Cr(VI). In addition, two strains isolated from the estuarine sediment of Tokyo Bay were found to be resistant to a concentration of 150 mg/l of Cr(VI). Furthermore, one Cr(VI)-reducing strain was found to remove 60 mg/l of Cr(VI) within 1 week and was identified as Streptomyces thermocarboxydus based on 16S rRNA gene analysis. The comparative evaluation with the type strain S. thermocarboxydus NBRC 16323 showed that our isolated strain had higher ability to grow at 27 °C and reduce Cr(VI) at a NaCl concentration of 6.0 % at 27 °C compared with the type strain NBRC 16323. These results indicate that our isolated strain have a potential ability to remove Cr(VI) from contaminated, highly saline sources without heating.

  4. Molecules to Ecosystems: Actinomycete Natural Products In situ

    PubMed Central

    Behie, Scott W.; Bonet, Bailey; Zacharia, Vineetha M.; McClung, Dylan J.; Traxler, Matthew F.

    2017-01-01

    Actinomycetes, filamentous actinobacteria found in numerous ecosystems around the globe, produce a wide range of clinically useful natural products (NP). In natural environments, actinomycetes live in dynamic communities where environmental cues and ecological interactions likely influence NP biosynthesis. Our current understating of these cues, and the ecological roles of NP, is in its infancy. We postulate that understanding the ecological context in which actinomycete metabolites are made is fundamental to advancing the discovery of novel NP. In this review we explore the ecological relevance of actinomycetes and their secondary metabolites from varying ecosystems, and suggest that investigating the ecology of actinomycete interactions warrants particular attention with respect to metabolite discovery. Furthermore, we focus on the chemical ecology and in situ analysis of actinomycete NP and consider the implications for NP biosynthesis at ecosystem scales. PMID:28144233

  5. Aerobic and microaerophilic actinomycetes of typical agropeat and peat soils

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Gryadunova, A. A.; Pozdnyakov, A. I.; Zvyagintsev, D. G.

    2008-02-01

    A high number (from tens of thousands to millions of CFU/g of soil) of actinomycetes and a high diversity of genera were found in typical peat and agropeat soils. Agricultural use increases the number and diversity of the actinomycete complexes of the peat soils. In the peat soils, the actinomycete complex is represented by eight genera: Streptomyces, Micromonospora, Streptosporangium, Actinomadura, Microbispora, Saccharopolyspora, Saccharomonospora, and Microtetraspora. A considerable share of sporangial forms in the actinomycete complex of the peat soils not characteristic of the zonal soils was revealed. The number of actinomycetes that develop under aerobic conditions is smaller by 10-100 times than that of aerobic forms in the peat soils. Among the soil actinomycetes of the genera Streptomyces, Micromonospora, Streptosporangium, Actinomadura, Microbispora, and Microtetraspora, the microaerophilic forms were found; among the Saccharopolyspora and Saccharomonospora, no microaerophilic representatives were revealed.

  6. Nonomuraea syzygii sp. nov., an endophytic actinomycete isolated from the roots of a jambolan plum tree (Syzygium cumini L. Skeels).

    PubMed

    Rachniyom, Hathairat; Matsumoto, Atsuko; Indananda, Chantra; Duangmal, Kannika; Takahashi, Yoko; Thamchaipenet, Arinthip

    2015-04-01

    A novel endophytic actinomycete, designated strain GKU 164(T), was isolated from the roots of a jambolan plum tree (Syzygium cumini L. Skeels), collected at Khao Khitchakut National Park, Chantaburi province, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain formed a distinct clade within the genus Nonomuraea , and was most closely related to Nonomuraea monospora PT708(T) (98.77% 16S rRNA gene sequence similarity) and Nonomuraea thailandensis KC-061(T) (98.73%). Strain GKU 164(T) formed a branched substrate and aerial hyphae that generated single spores with rough surfaces. The cell wall contained meso-diaminopimelic acid. The whole-cell sugars were madurose, galactose, mannose, ribose, rhamnose and glucose. The N-acyl type of muramic acid was acetyl. The predominant menaquinone was MK-9(H4) with minor amounts of MK-9(H6), MK-9(H2) and MK-9(H0). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannosides, phosphatidylmonomethylethanolamine, hydroxy-phosphatidylmonomethylethanolamine, an unidentified aminophosphoglycolipid and four unknown phospholipids. The major fatty acids were iso-C(16 : 0) and 10-methyl C(17 : 0). The genomic DNA G+C content was 70.4 mol%. Significant differences in the morphological, chemotaxonomical, and biochemical data together with DNA-DNA relatedness values between strain GKU 164(T) and type strains of closely related species, clearly demonstrated that strain GKU 164(T) represents a novel species of the genus Nonomuraea , for which the name Nonomuraea syzygii sp. nov. is proposed. The type strain is GKU 164(T) ( = BCC 70457(T) = NBRC 110400(T)).

  7. Antimicrobial Activities of Some Actinomycetes Isolated from Different Rhizospheric Soils in Tunisia.

    PubMed

    Trabelsi, Ines; Oves, Daniel; Manteca, Angel; Genilloud, Olga; Altalhi, Abdullah; Nour, Mohamed

    2016-08-01

    Fifty four isolates of actinomycetes were collected from four different rhizospheric soils: 18 strains from palm tree bark and soil, 12 strains from an olive field soil, 9 strains from a coastal forest, and 15 strains from an agriculture soil situated in the Algerian-Tunisian border (Oum Tboul). Based on morphological and cultural characters, the isolates were classified as Streptomyces (42 strains), Micromonospora (4 strains), Pseudonocardia (1 strain), Actinomadura (1 strain), Nocardia (1 strain), and non-Streptomyces (5 strains). More than half of the isolates inhibited at least one tested pathogenic microorganisms in liquid culture. In addition, antimicrobial activities of some strains were tested on solid culture. Several bioactive compounds were identified by liquid chromatography joined with low-resolution mass spectroscopy (LC/MS) and analysed by MEDINA's database and by the dictionary of natural products Chapman & Hall. An interesting chlorinated compound with the molecular formula C20H37ClN2O4, produced by three different strains (SF1, SF2, and SF5), was subject of an attempted purification. However, it was demonstrated using confocal microscopy and LC/MS high resolution that this compound is produced only on solid culture. These three potential antimicrobial isolates showed high similarity with Streptomyces thinghirensis and Streptomyces lienomycini, in terms of morphological characteristics and 16S rRNA gene sequences (bootstrap 97 %). All these findings prove the high antimicrobial diversity of the studied soils. The potential of the selected and other relatively unexplored extreme environments constitute a source of interesting actinomycete strains producing several biologically active secondary metabolites.

  8. Halophilic and halotolerant actinomycetes from a marine saltern of Goa, India producing anti-bacterial metabolites.

    PubMed

    Ballav, Shuvankar; Kerkar, Savita; Thomas, Sabu; Augustine, Nimmy

    2015-03-01

    Marine salterns are estuarine ecosystems in Goa, receiving inputs from riverine and marine waters. The Salinity fluctuates between 0 and 300 psu which makes it a conducive niche for salt tolerant and salt loving Actinomycetales. Halotolerant and halophilic Actinomycetales producing anti-bacterial metabolites were studied from crystallizer pond sediments of Ribandar saltern, Goa. Three media viz. Starch casein, R2A and Inorganic salt starch agar at four different salinities (35, 50, 75 and 100 psu) were used for isolation. R2A agar at 35 psu was the most preferred by hypersaline actinomycetes. The dominant group was halotolerant Streptomyces spp. others being rare actinomycetes viz. Nocardiopsis, Micromonospora and Kocuria spp. More than 50% of the isolates showed anti-bacterial activity against one or more of the fifteen human pathogens tested. Eight strains from 4 genera showed consistent anti-bacterial activity and studied in detail. Most halotolerant isolates grew from 0 to 75 psu, with optimum antibiotic production at 35 psu whereas halophiles grew at 20 to 100 psu with optimum antibiotic production at 35 psu. Four Streptomyces strains showed multiple inhibition against test organisms while four rare actinomycetes were specific in their inhibitory activity. This is the first report of a halophilic Kocuria sp., Nocardiopsis sp., and halotolerant Micromonospora sp. producing anti-bacterial compound(s) against Staphylococcus aureus, Staphylococcus citreus, and Vibrio cholerae, respectively. Sequential extraction with varying polarity of organic solvents showed that the extracts inhibited different test pathogens. These results suggest that halophilic and halotolerant actinomycetes from marine salterns are a potential source of anti-bacterial compounds.

  9. Actinomadurol, an Antibacterial Norditerpenoid from a Rare Actinomycete, Actinomadura sp. KC 191.

    PubMed

    Shin, Bora; Kim, Byung-Yong; Cho, Eunji; Oh, Ki-Bong; Shin, Jongheon; Goodfellow, Michael; Oh, Dong-Chan

    2016-07-22

    A new secondary metabolite, actinomadurol (1), was isolated along with the known compound JBIR-65 (2) from a rare actinomycete, Actinomadura strain KC 191. The structure of 1 was established as a rare member of the bacterial C-19 norditerpenoid class by NMR data and ECD calculations. The absolute configuration of 2, which was previously reported without stereochemical analysis, was determined by using the modified Mosher's method and ECD calculations. Actinomadurol (1) exhibited potent antibacterial activity against pathogenic strains, such as Staphylococcus aureus, Kocuria rhizophila, and Proteus hauseri (MIC = 0.39-0.78 μg/mL), whereas JBIR-65 (2) showed no antibacterial activity.

  10. An actinomycete isolate from solitary wasp mud nest having strong antibacterial activity and kills the Candida cells due to the shrinkage and the cytosolic loss

    PubMed Central

    Kumar, Vijay; Naik, Bindu; Gusain, Omprakash; Bisht, Gajraj S.

    2014-01-01

    An actinomycetes strain designated as MN 2(6) was isolated from the solitary wasp mud nest. The isolate was identified using polyphasic taxonomy. It produced the extensive branched brown substrate and white aerial hyphae that changed into grayish black. The aerial mycelia produced the spiral spore chains with rugose spore surface. The growth was observed between temperature range of 27–37°C, pH 8–10 and below salt concentration of 6% (w/v). The comparative analysis of 16S rRNA gene sequence and phylogenetic relationship showed that strain MN 2(6) lies in clade with Streptomyces hygroscopicus subsp. hygroscopicus NRRL 2387T, Streptomyces sporocinereus NBRC 100766T and Streptomyces demainii NRRL B-1478T with which it shares a 16S rRNA gene sequence similarity of 99.3%. The strain MN 2(6) can be differentiated from type strains based on phenotypic characteristics. The strain MN 2(6) showed most promising activity against Gram-positive, Gram-negative bacteria, acid-fast bacilli and Candida species suggesting broad-spectrum characteristics of the active metabolite. Evaluation of anti-candidal activity of the metabolite of strain MN 2(6) by scanning electron microscopy (SEM) revealed changed external morphology of yeast. It kills the Candida cells due to the shrinkage and the cytosolic loss. However, further studies are required to elucidate the structure of the active metabolite produced by the isolate MN 2(6). PMID:25191320

  11. Lignin-solubilizing ability of actinomycetes isolated from termite (Termitidae) gut. [Streptomyces viridosporus

    SciTech Connect

    Pasti, M.B.; Crawford, D.L. ); Pometto, A.L., III ); Nuti, M.P. )

    1990-07-01

    The lignocellulose-degrading abilities of 11 novel actinomycete strains isolated from termite gut were determined and compared with that of the well-characterized actinomycete, Streptomyces viridosporus T7A. Lignocellulose bioconversion was followed by (i) monitoring the degradation of ({sup 14}C)lignin- and ({sup 14}C)cellulose-labeled phloem of Abies concolor to {sup 14}CO{sub 2} and {sup 14}C-labeled water-soluble products, (ii) determining lignocellulose, lignin, and carbohydrate losses resulting from growth on a lignocellulose substrate prepared from corn stalks (Zea mays), and (iii) quantifying production of a water-soluble lignin degradation intermediate (acid-precipitable polymeric lignin). Of the assays used, total lignocellulose weight loss was most useful in determining overall bioconversion ability but not in identifying the best lignin-solubilizing strains. A screening procedure based on {sup 14}CO{sub 2} evolution from ({sup 14}C-lignin)lignocellulose combined with measurement of acid-precipitable polymeric lignin yield was the most effective in identifying lignin-solubilizing strains. For the termite gut strains, the pH of the medium showed no increase after 3 weeks of growth on lignocellulose. This is markedly different from the pattern observed with S. viridosporus T7A, which raises the medium pH considerably. Production of extracellular peroxidases by the 11 strains and S. viridosporus T7A was followed for 5 days in liquid cultures. On the basis of an increase of specific peroxidase activity in the presence of lignocellulose in the medium, the actinomycetes could be placed into the same three groups.

  12. Micromonospora taraxaci sp. nov., a novel endophytic actinomycete isolated from dandelion root (Taraxacum mongolicum Hand.-Mazz.).

    PubMed

    Zhao, Junwei; Guo, Lifeng; He, Hairong; Liu, Chongxi; Zhang, Yuejing; Li, Chuang; Wang, Xiangjing; Xiang, Wensheng

    2014-10-01

    A novel actinomycete, designated strain NEAU-P5(T), was isolated from dandelion root (Taraxacum mongolicum Hand.-Mazz.). Strain NEAU-P5(T) showed closest 16S rRNA gene sequence similarity to Micromonospora chokoriensis 2-19/6(T) (99.5%), and phylogenetically clustered with Micromonospora violae NEAU-zh8(T) (99.3%), M. saelicesensis Lupac 09(T) (99.0%), M. lupini Lupac 14N(T) (98.8%), M. zeae NEAU-gq9(T) (98.4%), M. jinlongensis NEAU-GRX11(T) (98.3%) and M. zamorensis CR38(T) (97.9%). Phylogenetic analysis based on the gyrB gene sequence also indicated that the isolate clustered with the above type strains except M. violae NEAU-zh8(T). The cell-wall peptidoglycan consisted of meso-diaminopimelic acid and glycine. The major menaquinones were MK-9(H8), MK-9(H6) and MK-10(H2). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were C(16:0), iso-C(15:0) and C(17:0). Furthermore, some physiological and biochemical properties and low DNA-DNA relatedness values enabled the strain to be differentiated from members of closely related species. Therefore, it is proposed that strain NEAU-P5(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora taraxaci sp. nov. is proposed. The type strain is NEAU-P5(T) (=CGMCC 4.7098(T) = DSM 45885(T)).

  13. Knitted Strain Sensors: Impact of Design Parameters on Sensing Properties

    PubMed Central

    Atalay, Ozgur; Kennon, William Richard

    2014-01-01

    This paper presents a study of the sensing properties exhibited by textile-based knitted strain sensors. Knitted sensors were manufactured using flat-bed knitting technology, and electro-mechanical tests were subsequently performed on the specimens using a tensile testing machine to apply strain whilst the sensor was incorporated into a Wheatstone bridge arrangement to allow electrical monitoring. The sensing fabrics were manufactured from silver-plated nylon and elastomeric yarns. The component yarns offered similar diameters, bending characteristics and surface friction, but their production parameters differed in respect of the required yarn input tension, the number of conductive courses in the sensing structure and the elastomeric yarn extension characteristics. Experimental results showed that these manufacturing controls significantly affected the sensing properties of the knitted structures such that the gauge factor values, the working range and the linearity of the sensors varied according to the knitted structure. These results confirm that production parameters play a fundamental role in determining the physical behavior and the sensing properties of knitted sensors. It is thus possible to manipulate the sensing properties of knitted sensors and the sensor response may be engineered by varying the production parameters applied to specific designs. PMID:24608010

  14. Exploitation of phage battery in the search for bioactive actinomycetes.

    PubMed

    Kurtböke, D Ipek

    2011-02-01

    Screening of microbial natural products continues to represent an important route to the discovery of novel bioactive compounds for the development of new therapeutic agents, and actinomycetes are still the major producers of biopharmaceuticals. Selective isolation of bioactive actinomycete species, in particular the rare ones, has thus become a target for industrial microbiologists. In this context, bacteriophages have proven to be useful tools as (1) naturally present indicators of under-represented or rare actinomycete taxa in environmental samples, (2) indicators of the relatedness of bioactive taxa in target-directed search and discovery, (3) de-selection agents of unwanted taxa on isolation plates in target-specific search for rare actinomycete taxa, (4) tools in screening assays for specific targets. Against this background, a number of case studies are presented to illustrate the use of bacteriophages as tools in actinomycete-origin bioactive compound search and discovery programs.

  15. Computational methods in metabolic engineering for strain design.

    PubMed

    Long, Matthew R; Ong, Wai Kit; Reed, Jennifer L

    2015-08-01

    Metabolic engineering uses genetic approaches to control microbial metabolism to produce desired compounds. Computational tools can identify new biological routes to chemicals and the changes needed in host metabolism to improve chemical production. Recent computational efforts have focused on exploring what compounds can be made biologically using native, heterologous, and/or enzymes with broad specificity. Additionally, computational methods have been developed to suggest different types of genetic modifications (e.g. gene deletion/addition or up/down regulation), as well as suggest strategies meeting different criteria (e.g. high yield, high productivity, or substrate co-utilization). Strategies to improve the runtime performances have also been developed, which allow for more complex metabolic engineering strategies to be identified. Future incorporation of kinetic considerations will further improve strain design algorithms.

  16. A diaminopimelic acid auxotrophic Escherichia coli donor provides improved counterselection following intergeneric conjugation with actinomycetes.

    PubMed

    Allard, Nancy; Garneau, Daniel; Poulin-Laprade, Dominic; Burrus, Vincent; Brzezinski, Ryszard; Roy, Sébastien

    2015-08-01

    Considering the medical, biotechnological, and economical importance of actinobacteria, there is a continuous need to improve the tools for genetic engineering of a broad range of these microorganisms. Intergeneric conjugation has proven to be a valuable yet imperfect tool for this purpose. The natural resistance of many actinomycetes to nalidixic acid (Nal) is generally exploited to eliminate the sensitive Escherichia coli donor strain following conjugation. Nevertheless, Nal can delay growth and have other unexpected effects on the recipient strain. To provide an improved alternative to antibiotics, we propose a postconjugational counterselection using a diaminopimelic acid (DAP) auxotrophic donor strain. The DAP-negative phenotype was obtained by introducing a dapA deletion into the popular methylase-negative donor strain E. coli ET12567/pUZ8002. The viability of ET12567 and its ΔdapA mutant exposed to DAP deprivation or Nal selection were compared in liquid pure culture and after mating with Streptomyces coelicolor. Results showed that death of the E. coli ΔdapA Nal-sensitive donor strain occurred more efficiently when subjected to DAP deprivation than when exposed to Nal. Our study shows that postconjugational counterselection based on DAP deprivation circumvents the use of antibiotics and will facilitate the transfer of plasmids into actinomycetes with high biotechnological potential, yet currently not accessible to conjugative techniques.

  17. Nocardiopsis oceani sp. nov. and Nocardiopsis nanhaiensis sp. nov., actinomycetes isolated from marine sediment of the South China Sea.

    PubMed

    Pan, Hua-Qi; Zhang, Dao-Feng; Li, Li; Jiang, Zhao; Cheng, Juan; Zhang, Yong-Guang; Wang, Hong-Fei; Hu, Jiang-Chun; Li, Wen-Jun

    2015-10-01

    Two actinomycete strains, designated 10A08AT and 10A08BT, were isolated from marine sediment samples of the South China Sea and their taxonomic positions were determined by a polyphasic approach. The two Gram-stain-positive, aerobic strains produced branched substrate mycelium and aerial hyphae, and no diffusible pigment was produced in the media tested. At maturity, spore chains were formed on aerial hyphae and all mycelium fragmented with age. Whole-cell hydrolysates of both strains contained meso-diaminopimelic acid and no diagnostic sugars. Their predominant menaquinones (>10 %) were MK-9(H4), MK-9(H6) and MK-10(H6) for strain 10A08AT and MK-9(H4), MK-9(H6), MK-10(H4) and MK-10(H6) for strain 10A08BT. The polar lipids detected from the two strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and unknown phosphoglycolipids and phospholipids. The major fatty acids (>10 %) of both strains were iso-C16 : 0 and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B). The genomic DNA G+C contents of strains 10A08AT and 10A08BT were 70.9 and 71.6 mol%, respectively. On the basis of 16S rRNA gene sequence similarities, the two strains were shown to be most closely related to species of the genus Nocardiopsis. DNA–DNA hybridization relatedness values of < 70 % between these two isolates and their closest neighbour, Nocardiopsis terrae YIM 90022T, and between the two strains supported the conclusion that they represent two novel species. Based on phylogenetic analysis and phenotypic and genotypic data, it is concluded that the two isolates belong to the genus Nocardiopsis, and the names Nocardiopsis oceani sp. nov. (type strain 10A08AT = DSM 45931T = BCRC 16951T) and Nocardiopsis nanhaiensis sp. nov. (type strain 10A08BT = CGMCC 47227T = BCRC 16952T) are proposed.

  18. Screening and characterization of protease producing actinomycetes from marine saltern.

    PubMed

    Suthindhiran, Krish; Jayasri, Mangalam Achuthananda; Dipali, Dipa; Prasar, Apurva

    2014-10-01

    In the course of systematic screening program for bioactive actinomycetes, an alkaline protease producing halophilic strain Actinopolyspora sp. VITSDK2 was isolated from marine saltern, Southern India. The strain was identified as Actinopolyspora based on its phenotypic and phylogenetic characters. The protease was partially purified using ammonium sulfate precipitation and subsequently by DEAE cellulose column chromatography. The enzyme was further purified using HPLC and the molecular weight was found to be 22 kDa as determined by SDS-PAGE analysis. The purified protease exhibited pH stability in a wide range of 4-12 with optimum at 10.0. The enzyme was found to be stable between 25 and 80 °C and displayed a maximum activity at 60 °C. The enzyme activity was increased marginally in presence of Mn(2+) , Mg(2+) , and Ca(2+) and decreased in presence of Cu(2+) . PMSF and DFP completely inhibited the activity suggesting it belongs to serine protease. Further, the proteolytic activity was abolished in presence of N-tosyl-L-lysine chloromethyl ketone suggesting this might be chymotrypsin-like serine protease. The protease was 96% active when kept for 10 days at room temperature. The results indicate that the enzyme belong to chymotrypsin-like serine protease exhibiting both pH and thermostability, which can be used for various applications in industries.

  19. Nocardia kroppenstedtii sp. nov., an actinomycete isolated from a lung transplant patient with a pulmonary infection.

    PubMed

    Jones, Amanda L; Fisher, Andrew J; Mahida, Rahul; Gould, Kate; Perry, John D; Hannan, Margaret M; Judge, Eoin P; Brown, Ros; Boagey, Kimberley; Goodfellow, Michael

    2014-03-01

    A novel actinomycete, strain N1286(T), isolated from a lung transplant patient with a pulmonary infection, was provisionally assigned to the genus Nocardia. The strain had chemotaxonomic and morphological properties typical of members of the genus Nocardia and formed a distinct phyletic line in the Nocardia 16S rRNA gene tree. Isolate N1286(T) was most closely related to Nocardia farcinica DSM 43665(T) (99.8% gene sequence similarity) but could be distinguished from the latter by the low level of DNA-DNA relatedness. These strains were also distinguishable on the basis of a broad range of phenotypic properties. It is concluded that strain N1286(T) represents a novel species of the genus Nocardia for which the name Nocardia kroppenstedtii sp. nov. is proposed. The type strain is N1286(T) ( = DSM 45810(T) = NCTC 13617(T)).

  20. Diversity and biosynthetic potential of culturable actinomycetes associated with marine sponges in the China Seas.

    PubMed

    Xi, Lijun; Ruan, Jisheng; Huang, Ying

    2012-01-01

    The diversity and secondary metabolite potential of culturable actinomycetes associated with eight different marine sponges collected from the South China Sea and the Yellow sea were investigated. A total of 327 strains were isolated and 108 representative isolates were selected for phylogenetic analysis. Ten families and 13 genera of Actinomycetales were detected, among which five genera represent first records isolated from marine sponges. Oligotrophic medium M5 (water agar) proved to be efficient for selective isolation, and "Micromonospora-Streptomyces" was proposed as the major distribution group of sponge-associated actinomycetes from the China Seas. Ten isolates are likely to represent novel species. Sponge Hymeniacidon perleve was found to contain the highest genus diversity (seven genera) of actinomycetes. Housekeeping gene phylogenetic analyses of the isolates indicated one ubiquitous Micromonospora species, one unique Streptomyces species and one unique Verrucosispora phylogroup. Of the isolates, 27.5% displayed antimicrobial activity, and 91% contained polyketide synthase and/or nonribosomal peptide synthetase genes, indicating that these isolates had a high potential to produce secondary metabolites. The isolates from sponge Axinella sp. contained the highest presence of both antimicrobial activity and NRPS genes, while those from isolation medium DNBA showed the highest presence of antimicrobial activity and PKS I genes.

  1. Actinomycete complexes in soils of industrial and residential zones in the city of Kirov

    NASA Astrophysics Data System (ADS)

    Shirokikh, I. G.; Solov'eva, E. S.; Ashikhmina, T. Ya.

    2014-02-01

    The number, diversity, and structure of the actinomycetal complexes in the soils of the industrial and residential zones of the city of Kirov are considered. The total content of mobile cadmium, zinc, lead, iron, and nickel in the soils of the industrial biotopes was 1.8 and 6.0 times higher than their concentration in the soils of the residential and background zones, respectively. In the heavy metal (HM)-polluted soils, the share of actinomycetes in the total number of prokaryotes and the relative abundance of the micromono-spores in the actinomycetal complex were much higher and the species diversity of the streptomycetes was lower than these characteristics in the soils of the residential zone. The differences in the composition of the mycelial prokaryote complexes appear to be related to the selective resistance of some of their representatives to heavy metals. The possibility to select the strains resistant to HMs and suitable for use in the bioremediation of polluted soils is considered.

  2. Acidophilic actinomycetes from rhizosphere soil: diversity and properties beneficial to plants.

    PubMed

    Poomthongdee, Nalin; Duangmal, Kannika; Pathom-aree, Wasu

    2015-02-01

    Three hundred and fifty-one isolates of actinomycetes were recovered from 21 rhizospheric soil samples using acidified media of pH 5.5. They were evaluated for their antifungal, siderophore production and phosphate solubilization activities. The total count of actinomycetes growing on acidified starch casein agar and Gause no. 1 agar were below 2.48 × 10(4) CFU g(-1) soil. Two hundred and twelve isolates were assigned to acidophiles and the remaining 139 isolates were neutrophiles. Of these actinomycetes, 57.8, 32.5 and 50.4%, showed antagonistic activity against three rice pathogenic fungi; Fusarium moniliforme, Helminthosporium oryzae and Rhizoctonia solani, respectively. More than half of the isolates (68.1%) inhibited at least one tested pathogenic fungus, whereas 25.9% exhibited antifungal activities against all tested fungi. Three hundred and thirty-eight isolates (96.3%) produced siderophore and 266 isolates (75.8%) solubilized phosphate. A greater proportion of the acidophilic actinomycetes exhibited antifungal, siderophore production and phosphate solubilization activity compared with the neutrophiles. Three hundred and twenty-five isolates (92.6%) were classified as streptomycetes based on their morphological characteristics and the presence of the LL-isomeric form of diaminopimelic acid in whole-cell hydrolysates. The 16S ribosomal RNA (rRNA) gene analysis of representative non-streptomycete strains showed that the isolates belonged to seven genera, that is, Allokutzneria, Amycolatopsis, Mycobacterium, Nocardia, Nonomuraea, Saccharopolyspora and Verrucosispora. The potential antifungal acidophilic isolates, R9-4, R14-1, R14-5 and R20-5, showed close similarity to Streptomyces misionensis NBRC 13063(T) (AB184285) in terms of morphological characteristics and 16S rRNA gene sequences.

  3. Streptomyces halophytocola sp. nov., an endophytic actinomycete isolated from the surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour.

    PubMed

    Qin, Sheng; Bian, Guang-Kai; Tamura, Tomohiko; Zhang, Yue-Ji; Zhang, Wen-Di; Cao, Cheng-Liang; Jiang, Ji-Hong

    2013-08-01

    A novel actinomycete, designated KLBMP 1284(T), was isolated from the surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour. collected from the city of Nantong, Jiangsu Province, east China. The strain was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. Analysis of the 16S rRNA gene sequence of strain KLBMP 1284(T) revealed that the strain formed a distinct clade within the phylogenetic tree based on 16S rRNA gene sequences and the highest sequence similarity (99.43 %) was to Streptomyces sulphureus NRRL B-1627(T). 16S rRNA gene sequence similarity to other species of the genus Streptomyces was lower than 97 %. Based on DNA-DNA hybridization values and comparison of morphological and phenotypic data, KLBMP 1284(T) could be distinguished from the closest phylogenetically related species, Streptomyces sulphureus NRRL B-1627(T). Thus, based on these data, it is evident that strain KLBMP 1284(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces halophytocola sp. nov. is proposed. The type strain is KLBMP 1284(T) (= KCTC 19890(T) = NBRC 108770(T)).

  4. Streptomyces oceani sp. nov., a new obligate marine actinomycete isolated from a deep-sea sample of seep authigenic carbonate nodule in South China Sea.

    PubMed

    Tian, Xin-Peng; Xu, Ying; Zhang, Jing; Li, Jie; Chen, Zhong; Kim, Chang-Jin; Li, Wen-Jun; Zhang, Chang-Sheng; Zhang, Si

    2012-08-01

    A novel aerobic actinomycete strain, designated as SCSIO 02100(T), was isolated from a deep sea sediment sample collected from Northern South China Sea at a depth of 578 m. This isolate requires sea water or a sodium-supplemented medium for growth. BLAST searches based on the almost full length of the 16S rRNA gene sequence, showed that strain SCSIO 02100(T) had the highest similarities with Streptomyces armeniacus (JCM 3070(T)) (97.1 %). Phylogenetic trees reconstructed on the basis of 16S rRNA gene sequences revealed that strain SCSIO 02100(T) formed a distinct lineage with S. nanshensis SCSIO 01066(T) with 96.9 % similarity. Further analysis of the polyphasic taxonomic data, including morphological, phenotypic and chemotaxonomic properties, showed that strain SCSIO 02100(T) could be readily distinguished from the most closely related members of the genus Streptomyces. Thus, based on the polyphasic taxonomic data, a novel species, Streptomyces oceani sp. nov., is proposed, with the type strain SCSIO 02100(T) (=DSM 42043(T) = CGMCC 4.7007(T)).

  5. Detection, distribution, and organohalogen compound discovery implications of the reduced flavin adenine dinucleotide-dependent halogenase gene in major filamentous actinomycete taxonomic groups.

    PubMed

    Gao, Peng; Huang, Ying

    2009-07-01

    Halogenases have been shown to play a significant role in biosynthesis and introducing the bioactivity of many halogenated secondary metabolites. In this study, 54 reduced flavin adenine dinucleotide (FADH(2))-dependent halogenase gene-positive strains were identified after the PCR screening of a large collection of 228 reference strains encompassing all major families and genera of filamentous actinomycetes. The wide distribution of this gene was observed to extend to some rare lineages with higher occurrences and large sequence diversity. Subsequent phylogenetic analyses revealed that strains containing highly homologous halogenases tended to produce halometabolites with similar structures, and halogenase genes are likely to propagate by horizontal gene transfer as well as vertical inheritance within actinomycetes. Higher percentages of halogenase gene-positive strains than those of halogenase gene-negative ones contained polyketide synthase genes and/or nonribosomal peptide synthetase genes or displayed antimicrobial activities in the tests applied, indicating their genetic and physiological potentials for producing secondary metabolites. The robustness of this halogenase gene screening strategy for the discovery of particular biosynthetic gene clusters in rare actinomycetes besides streptomycetes was further supported by genome-walking analysis. The described distribution and phylogenetic implications of the FADH(2)-dependent halogenase gene present a guide for strain selection in the search for novel organohalogen compounds from actinomycetes.

  6. Broad Spectrum Antimicrobial Activity of Forest-Derived Soil Actinomycete, Nocardia sp. PB-52

    PubMed Central

    Sharma, Priyanka; Kalita, Mohan C.; Thakur, Debajit

    2016-01-01

    A mesophilic actinomycete strain designated as PB-52 was isolated from soil samples of Pobitora Wildlife Sanctuary of Assam, India. Based on phenotypic and molecular characteristics, the strain was identified as Nocardia sp. which shares 99.7% sequence similarity with Nocardia niigatensis IFM 0330 (NR_112195). The strain is a Gram-positive filamentous bacterium with rugose spore surface which exhibited a wide range of antimicrobial activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative bacteria, and yeasts. Optimization for the growth and antimicrobial activity of the strain PB-52 was carried out in batch culture under shaking condition. The optimum growth and antimicrobial potential of the strain were recorded in GLM medium at 28°C, initial pH 7.4 of the medium and incubation period of 8 days. Based on polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS) gene-targeted PCR amplification, the occurrence of both of these biosynthetic pathways was detected which might be involved in the production of antimicrobial compounds in PB-52. Extract of the fermented broth culture of PB-52 was prepared with organic solvent extraction method using ethyl acetate. The ethyl acetate extract of PB-52 (EA-PB-52) showed lowest minimum inhibitory concentration (MIC) against S. aureus MTCC 96 (0.975 μg/mL) whereas highest was recorded against Klebsiella pneumoniae ATCC 13883 (62.5 μg/mL). Scanning electron microscopy (SEM) revealed that treatment of the test microorganisms with EA-PB-52 destroyed the targeted cells with prominent loss of cell shape and integrity. In order to determine the constituents responsible for its antimicrobial activity, EA-PB-52 was subjected to chemical analysis using gas chromatography-mass spectrometry (GC-MS). GC-MS analysis showed the presence of twelve different chemical constituents in the extract, some of which are reported to possess diverse biological activity. These

  7. New design for temperature-strain discrimination using fiber Bragg gratings embedded in laminated composites

    NASA Astrophysics Data System (ADS)

    Rodriguez-Cobo, L.; Marques, A. T.; López-Higuera, J. M.; Santos, J. L.; Frazão, O.

    2013-10-01

    A new smart structure based on fiber Bragg gratings (FBGs) embedded into composite laminates for temperature and strain simultaneous measurement has been designed and experimentally tested. Two holes have been drilled at preset locations in the composite plate to create different strain sensitivities at different locations. The proposed design has been compared to three reference sensing heads also based on embedding FBGs into composite materials. Experimental results agree remarkably well with mechanical simulations and validate all the tested designs for the temperature-strain discrimination. Based on the same principle, another sensing head with a long single FBG embedded has also been designed and experimentally tested, obtaining temperature independent strain measurement.

  8. Effects of Actinomycete Secondary Metabolites on Sediment Microbial Communities.

    PubMed

    Patin, Nastassia V; Schorn, Michelle; Aguinaldo, Kristen; Lincecum, Tommie; Moore, Bradley S; Jensen, Paul R

    2017-02-15

    Marine sediments harbor complex microbial communities that remain poorly studied relative to other biomes such as seawater. Moreover, bacteria in these communities produce antibiotics and other bioactive secondary metabolites, yet little is known about how these compounds affect microbial community structure. In this study, we used next-generation amplicon sequencing to assess native microbial community composition in shallow tropical marine sediments. The results revealed complex communities comprised of largely uncultured taxa, with considerable spatial heterogeneity and known antibiotic producers comprising only a small fraction of the total diversity. Organic extracts from cultured strains of the sediment-dwelling actinomycete genus Salinispora were then used in mesocosm studies to address how secondary metabolites shape sediment community composition. We identified predatory bacteria and other taxa that were consistently reduced in the extract-treated mesocosms, suggesting that they may be the targets of allelopathic interactions. We tested related taxa for extract sensitivity and found general agreement with the culture-independent results. Conversely, several taxa were enriched in the extract-treated mesocosms, suggesting that some bacteria benefited from the interactions. The results provide evidence that bacterial secondary metabolites can have complex and significant effects on sediment microbial communities.

  9. Complete genome sequence of the soil actinomycete Kocuria rhizophila.

    PubMed

    Takarada, Hiromi; Sekine, Mitsuo; Kosugi, Hiroki; Matsuo, Yasunori; Fujisawa, Takatomo; Omata, Seiha; Kishi, Emi; Shimizu, Ai; Tsukatani, Naofumi; Tanikawa, Satoshi; Fujita, Nobuyuki; Harayama, Shigeaki

    2008-06-01

    The soil actinomycete Kocuria rhizophila belongs to the suborder Micrococcineae, a divergent bacterial group for which only a limited amount of genomic information is currently available. K. rhizophila is also important in industrial applications; e.g., it is commonly used as a standard quality control strain for antimicrobial susceptibility testing. Sequencing and annotation of the genome of K. rhizophila DC2201 (NBRC 103217) revealed a single circular chromosome (2,697,540 bp; G+C content of 71.16%) containing 2,357 predicted protein-coding genes. Most of the predicted proteins (87.7%) were orthologous to actinobacterial proteins, and the genome showed fairly good conservation of synteny with taxonomically related actinobacterial genomes. On the other hand, the genome seems to encode much smaller numbers of proteins necessary for secondary metabolism (one each of nonribosomal peptide synthetase and type III polyketide synthase), transcriptional regulation, and lateral gene transfer, reflecting the small genome size. The presence of probable metabolic pathways for the transformation of phenolic compounds generated from the decomposition of plant materials, and the presence of a large number of genes associated with membrane transport, particularly amino acid transporters and drug efflux pumps, may contribute to the organism's utilization of root exudates, as well as the tolerance to various organic compounds.

  10. Diversity and bioprospecting of actinomycete endophytes from the medicinal plants.

    PubMed

    Nalini, M S; Prakash, H S

    2017-04-01

    The endophytic actinomycetes constitute one of the fascinating group of microorganisms associated with a wide range of plant species. The diversity of actinomycetes in plants and their tissue parts is a matter of debate as no consensus are derived between individual studies. Nevertheless, their diversity correlates with the occurrence in plant species harboured in unique regions of biologically diverse areas called "hot spots." Recent advances in the isolation techniques have facilitated the isolation of rare taxa from these environments. The biosynthetic ability of the endophytic actinomycetes has proven beyond doubt that these organisms have the potential to synthesize an array of compounds with novelty in structure and bioactivity and as a result are preferred in the natural product screening programs. In the years to come, the scientific world may await to discover many more novel actinomycete taxa with metabolic diversity and applications in therapeutics.

  11. Actinomycetes in garden soils of the city of Kirov

    NASA Astrophysics Data System (ADS)

    Shirokikh, I. G.; Solov'eva, E. S.; Ashikhmina, T. Ya.

    2013-05-01

    The population density, diversity, and structure of the actinomycetic complexes were studied in garden soils of the city of Kirov. The relationships between the structure of the complexes and the acidity, the concentrations of the mobile forms of heavy metals, and the soil humus content were analyzed. The specific features of the actinomycetic population in the garden soils of the city in comparison with the transport ecotopes and suburban territories were revealed. It was demonstrated that the actinomycetic complexes in the garden soils preserve their structural similarity with the actinomycetic complexes of the suburban forest parks despite certain changes in the composition of the dominant species and the relative abundance of the separate taxa. The obtained data indicate that the garden plots in the city contribute to the preservation of ecologically balanced ecosystems.

  12. [Gene networks that regulate secondary metabolism in actinomycetes: pleiotropic regulators].

    PubMed

    Rabyk, M V; Ostash, B O; Fedorenko, V O

    2014-01-01

    Current advances in the research and practical applications of pleiotropic regulatory genes for antibiotic production in actinomycetes are reviewed. The basic regulatory mechanisms found in these bacteria are outlined. Examples described in the review show the importance of the manipulation of regulatory systems that affect the synthesis of antibiotics for the metabolic engineering of the actinomycetes. Also, the study of these genes is the basis for the development of genetic engineering approaches towards the induction of "cryptic" part of the actinomycetes secondary metabolome, which capacity for production of biologically active compounds is much bigger than the diversity of antibiotics underpinned by traditional microbiological screening. Besides the practical problems, the study of regulatory genes for antibiotic biosynthesis will provide insights into the process of evolution of complex regulatory systems that coordinate the expression of gene operons, clusters and regulons, involved in the control of secondary metabolism and morphogenesis of actinomycetes.

  13. Membrane-active metabolites produced by soil actinomycetes using chromatic phospholipid/polydiacetylene vesicles.

    PubMed

    Mehravar, Maryam; Sardari, Soroush; Owlia, Parviz

    2011-12-01

    Increased resistance of pathogens toward existing antibiotics has compelled the research efforts to introduce new antimicrobial substances. Drugs with new and less resistant-prone targets to antimicrobial activity have a high priority for drug development activities. Cell membrane seems to be a potential target for new antibiotic agent development to overcome resistance. In this study, A total number of 67 actinomycetes were isolated from the soil samples collected from desert, farming and mineral parts of Iran. We used a chromatic sensor as a membrane model that was set up for the target of antimicrobial metabolites of actinomycetes isolated from the soil. The sensors particles were composed of phospholipid and polymerized polydiacetylene (PDA) lipids. These polymers exhibited color change following interaction with membrane-active metabolites. The color change was due to structural disorder in the lipids following their interaction with membrane-active metabolites. The resultant color change was recorded by fluorescent microscope and easily recognizable by naked eye as well. Sixteen strains were isolated which produced antimicrobial metabolites and were effective against test microorganisms (Escherichia coli, Candida albicans and Saccharomyces cerevisiae ). A total number of 3 out of 16 strains produced membrane-active metabolites. These 3 strains were identified using 16s rRNA as Streptomyces sp and submitted to GenBank (accession no. JN180853; JN180854; JN180855).

  14. In vitro actinomycete biofilm development and inhibition by the polyene antibiotic, nystatin, on IUD copper surfaces.

    PubMed

    Shanmughapriya, Santhanam; Francis, Arumugam Lency; Kavitha, Senthil; Natarajaseenivasan, Kalimuthusamy

    2012-01-01

    The presence of intrauterine contraceptive devices (IUDs) gives a solid surface for attachment and an ideal niche for biofilm to form and flourish. Pelvic actinomycosis is often associated with the use of IUDs. Treatment of IUD-associated pelvic actinomycosis requires the immediate removal of the IUD. Therefore, this article presents in vitro evidence to support the use of novel antibiotics in the treatment of actinomycete biofilms. Twenty one clinical actinomycetes isolates from endocervical swabs of IUD wearers were assessed for their biofilm forming ability. An in vitro biofilm model with three isolates, Streptomyces strain A4, Nocardia strain C15 and Nocardia strain C17 was subjected to treatment with nystatin. Inhibition of biofilm formation by nystatin was found to be concentration dependent, with MBIC50 values in the range 0.08-0.16 mg ml(-1). Furthermore, at a concentration of 0.16 mg ml(-1), nystatin inhibited the twitching motility of the isolates, providing evidence for a possible mechanism of biofilm inhibition.

  15. Isolation and screening of antibiotic producing actinomycetes from soils in Gondar town, North West Ethiopia

    PubMed Central

    Bizuye, Abebe; Moges, Feleke; Andualem, Berhanu

    2013-01-01

    Objective To isolate and screen antibiotic producing actinomycetes from potential soil samples of Gondar town, Ethiopia. Methods Fifteen soil samples were collected, serially diluted and spread on starch casein and oat meal agar supplemented with amoxicillin and cyclohexamide for inhibition of bacteria and fungi, respectively. Cross streak method was used to check antagonistic activity of isolated actinomycetes against test organisms. Solid state fermentation and crude extraction were used for the production of antibiotics from isolates. Agar well diffusion was used for antimicrobial activity of crude extracts against test organisms. Results Three isolates (Ab18, Ab28 and Ab43) have been shown high antagonistic activity during primary screening. Inhibition zones obtained from crude extracts showed significance differences when compared with standard antibiotics tested against test organisms (P<0.05). Inhibition zone of crude extracts from isolate Ab18 against Klebsiella pneumonia ATCC7000603 and Escherichia coli ATCC25922 were (14±1) mm and (35±1) mm, respectively which were strong active when compared to amoxicillin (0 mm) and tetracycline [(13±1) mm for Klebsiella pneumonia ATCC7000603 and (33±1) mm for Escherichia coli ATCC25922]. Crude extracts from isolate Ab18 showed (20±1) mm and (15±1) mm inhibition zones against methicillin resistant Staphylococcus aureus strains 2 (MRSA2) and MRSA4, respectively. Crude extract from isolate Ab43 has shown inhibition zones of (16±1) mm and (17±1) mm against MRSA2 and MRSA4, respectively. Combination of Ab18 and Ab43 has shown high antimicrobial activity (18±1) mm against MRSA2 and MRSA4. Conclusions There was not any scientific report on soil actinomycetes producing antibiotic in the study areas. Therefore, isolation and screening of actinomycetes from such areas in optimum condition may contribute the discovery of new antibiotics. Potent antibiotics from these actinomycetes could contribute a lot to fight against

  16. Extremophilic and extremotolerant actinomycetes in different soil types

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Manucharova, N. A.; Zvyagintsev, D. G.

    2011-04-01

    Problems on the resistance of soil actinomycetes to various environmental factors (pH, salinity, temperature, and moisture) are discussed. Actinomycetes as a special group of prokaryotes were revealed to have a greater range of tolerance to these factors than was thought earlier. The regularities of the distribution of extremophilic and extremotolerant actinomycetes developing in unusual for mycelial bacteria conditions, their structural-functional characteristics, and their taxonomic composition were determined. The predominance of acidophilic representatives of the Micromonospora genus in acid soils (typical peat, soddy-podzolic, and taiga podzol) and the haloalkaliphilic Streptomyces pluricilirescens and S. prunicolor species in desert saline soils are shown. The specific features of the actinomycete complexes on thermal fields of the weakly developed stratified volcanic soils are described. In these complexes, the thermophilic forms were represented only by species of the Micromonospora genus; and the mesophilic forms, by Microbispora species. In the periodically heated desert soils, among the thermophilic actinomycetes, representatives of rare Actinomadura, Saccharopolyspora and Streptosporangium genera along with Streptomyces species were indicated. The mechanisms of the resistance of the actinomycetes to the extreme environmental conditions are discussed.

  17. Diversity and bioactivity of actinomycetes from marine sediments of the Yellow Sea

    NASA Astrophysics Data System (ADS)

    Zhang, Shumin; Ye, Liang; Tang, Xuexi

    2012-03-01

    Among the 116 actinomycetes collected from marine sediments of the Yellow Sea, 56 grew slowly and appeared after 2-3 weeks of incubation. Among the 56 strains, only 3 required seawater (SW) for growth, and 21 grew well in the medium prepared with SW rather than distilled water (DW), while the remaining 32 grew well either with SW or with DW. Six representatives with different morphological characteristics, including 1 SW-requiring strain and 5 well-growing with SW strains, were selected for phylogenetic analysis based on 16S rRNA gene. Two strains belong to Micrococcaceae and Nocardiopsaceae respectively. The other 4 strains belong to the family of Streptomycetaceae. In the analyzed 6 strains, one was related to Nocardiopsis spp. and the other three were related to Streptomyces spp., representing new taxa. Bioactivity testing of fermentation products from 3 SW-requiring strains and 21 well-growing with SW strains revealed that 17 strains possessed remarkable activities against gram-positive pathogen or/and tumor cells, suggesting that they were prolific resources for natural drug discovery.

  18. Antimicrobial potential of Halophilic actinomycetes against multi drug resistant (MDR) ventilator associated pneumonia causing bacterial pathogens.

    PubMed

    Aslam, Sana; Sajid, Imran

    2016-03-01

    A collection of forty halophilic actinomycetes isolated from water and mud samples of the saline lake at Kalar Kahar, salt range, Pakistan, was screened to investigate their antimicrobial potential against multi drug resistant (MDR) ventilator associated pneumonia causing bacterial pathogens. The isolates exhibited significant tolerance to alkaline conditions and grew well at pH 9-11. The taxonomic status of the isolated strains was determined by morphological, biochemical and physiological characterization and by 16s rRNA gene sequencing. The results revealed that majority of the isolates (90%) belong to the genus Streptomyces. Most of the isolates exhibited remarkable antimicrobial activity up to 20mm zone of inhibition against MDR ventilator associated pneumonia causing bacteria including Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumoniae, Escherichia coli, Enterobacter and Acinetobacter spp. Additionally the isolates showed moderate to high cytotoxicity in the range of 40 to 80% larval mortality against Artemia salina in a micro well cytotoxicity assay. The chemical screening or the so called metabolic fingerprinting of the methanolic extracts of each isolate, by thin layer chromatography (TLC) using various staining reagents and by high performance liquid chromatography (HPLC-UV), indicated an impressive diversity of the compounds produced by these strains. The study reveals that these halophilic actinomycetes are a promising source of bioactive compounds. The preparative scale fermentation, isolation, purification and structure elucidation of the compounds produced by them may yield novel antimicrobial or chemotherapeutic agents.

  19. Actinomadura jiaoheensis sp. nov. and Actinomadura sporangiiformans sp. nov., two novel actinomycetes isolated from muddy soil and emended description of the genus Actinomadura.

    PubMed

    Zhao, Junwei; Guo, Lifeng; Sun, Pengyu; Han, Chuanyu; Bai, Lu; Liu, Chongxi; Li, Yunxi; Xiang, Wensheng; Wang, Xiangjing

    2015-12-01

    Two novel actinomycetes, designated strains NEAU-Jh1-3(T) and NEAU-Jh2-5(T), were isolated from muddy soil collected from a riverbank in Jiaohe, Jilin Province, north China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The 16S rRNA gene sequence analysis showed that the two novel isolates exhibited 99.9 % 16S rRNA gene sequence similarity with each other and that they are closely related to Actinomadura viridis IFO 15238(T) (99.6, 99.6 %) and Actinomadura vinacea IFO 14688(T) (99.3, 99.3 %). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the two cultures clustered together and formed a cluster with A. viridis IFO 15238(T), A. vinacea IFO 14688(T) and Actinomadura rugatobispora IFO 14382(T). However, the DNA-DNA hybridization value between strains NEAU-Jh1-3(T) and NEAU-Jh2-5(T) was 63.6 %, and the values between the two strains and their close phylogenetic relatives were also below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, the two strains can be distinguished from each other and their close phylogenetic relatives. Thus, strains NEAU-Jh1-3(T) and NEAU-Jh2-5(T) represent two novel species of the genus Actinomadura, for which the names Actinomadura jiaoheensis sp. nov. and Actinomadura sporangiiformans sp. nov. are proposed. The type strains are NEAU-Jh1-3(T) (=CGMCC 4.7197(T) = JCM 30341(T)) and NEAU-Jh2-5(T) (=CGMCC 4.7211(T) = JCM 30342(T)), respectively.

  20. Activation and products of the cryptic secondary metabolite biosynthetic gene clusters by rifampin resistance (rpoB) mutations in actinomycetes.

    PubMed

    Tanaka, Yukinori; Kasahara, Ken; Hirose, Yutaka; Murakami, Kiriko; Kugimiya, Rie; Ochi, Kozo

    2013-07-01

    A subset of rifampin resistance (rpoB) mutations result in the overproduction of antibiotics in various actinomycetes, including Streptomyces, Saccharopolyspora, and Amycolatopsis, with H437Y and H437R rpoB mutations effective most frequently. Moreover, the rpoB mutations markedly activate (up to 70-fold at the transcriptional level) the cryptic/silent secondary metabolite biosynthetic gene clusters of these actinomycetes, which are not activated under general stressful conditions, with the exception of treatment with rare earth elements. Analysis of the metabolite profile demonstrated that the rpoB mutants produced many metabolites, which were not detected in the wild-type strains. This approach utilizing rifampin resistance mutations is characterized by its feasibility and potential scalability to high-throughput studies and would be useful to activate and to enhance the yields of metabolites for discovery and biochemical characterization.

  1. EMILiO: a fast algorithm for genome-scale strain design.

    PubMed

    Yang, Laurence; Cluett, William R; Mahadevan, Radhakrishnan

    2011-05-01

    Systems-level design of cell metabolism is becoming increasingly important for renewable production of fuels, chemicals, and drugs. Computational models are improving in the accuracy and scope of predictions, but are also growing in complexity. Consequently, efficient and scalable algorithms are increasingly important for strain design. Previous algorithms helped to consolidate the utility of computational modeling in this field. To meet intensifying demands for high-performance strains, both the number and variety of genetic manipulations involved in strain construction are increasing. Existing algorithms have experienced combinatorial increases in computational complexity when applied toward the design of such complex strains. Here, we present EMILiO, a new algorithm that increases the scope of strain design to include reactions with individually optimized fluxes. Unlike existing approaches that would experience an explosion in complexity to solve this problem, we efficiently generated numerous alternate strain designs producing succinate, l-glutamate and l-serine. This was enabled by successive linear programming, a technique new to the area of computational strain design.

  2. Pectinolytic Enzymes from Actinomycetes for the Degumming of Ramie Bast Fibers

    PubMed Central

    Brühlmann, Fredi; Kim, Kwi Suk; Zimmerman, Wolfgang; Fiechter, Armin

    1994-01-01

    Actinomycetes isolated from 10 different soil and compost samples were screened for production of pectinolytic enzyme activities when grown on pectin-containing solid and liquid media. Pectinolytic enzymes, detected by using plate diffusion tests with a medium containing ramie (Boehmeria nivea) plant material as the sole carbon source, were mainly pectate lyases, but low activities of pectinesterases were also observed. Polygalacturonases and polymethylgalacturonases were not produced. Multiple forms of pectate lyases were detected in the culture supernatants of some of the strains by using the zymogram technique of isoelectric focusing gels. Xylanolytic and cellulolytic activities were always found to be associated with pectinolytic activities. None of the pectinolytic enzymes were produced in a medium with glucose as the sole carbon source. Treatment of ramie bast fibers with crude enzyme preparations from a selection of strains showed a good correlation between the pectate lyase activity applied and the degumming effect, resulting in good separation of the bast fibers. Images PMID:16349296

  3. Materials design and processings for industrial high-strain-rate superplastic forming

    SciTech Connect

    Hosokawa, H.; Higashi, K.

    2000-07-01

    The optimum materials design in microstructural control could be developed for the high-strain-rate superplastic materials in the industrial scale. In the present work, it is reported that the high-performance-engine pistons with near-net-shape can be fabricated by the superplastic forging technology in the high-strain-rate superplastic PM Al-Si based alloy, which is produced by using this optimum materials design.

  4. [Ecophysiological Characteristics of actinomycetes of desert soils of Mongolia].

    PubMed

    Zenova, G M; Kozhevin, P A; Manucharova, N A; Lubsanova, D A; Dubrova, M S

    2014-01-01

    It is shown that the actinomycete complex in steppe-desert light brown salty soil of desert steppes of Mongolia is represented by the genera Streptomyces and Micromonospora. The species diversity of the genus Streptomyces, which dominates the complex, decreases with increasing osmolarity of the medium. The influence of environmental factors--temperature and osmolarity of medium--on the development of metabolically active members of the phylum Actinobacteria in the domain Bacteria of the prokaryotic microbial soil community was established. The proportion of metabolically active bacteria belonging to Actinobacteria increases with increasing osmolarity and incubation temperature of soil. The dominance of the filamentous metabolically active members of the phylum Actinobacteria over the unicellular organisms was shown. The halotolerant actinomycetes isolated from the steppe-desert soils were alkalotolerant, xerophilic, and thermotolerant and exhibited antimicrobial activity with respect to Gram-positive bacteria and actinomycetes.

  5. Synthetic polyester-hydrolyzing enzymes from thermophilic actinomycetes.

    PubMed

    Wei, Ren; Oeser, Thorsten; Zimmermann, Wolfgang

    2014-01-01

    Thermophilic actinomycetes produce enzymes capable of hydrolyzing synthetic polyesters such as polyethylene terephthalate (PET). In addition to carboxylesterases, which have hydrolytic activity predominantly against PET oligomers, esterases related to cutinases also hydrolyze synthetic polymers. The production of these enzymes by actinomycetes as well as their recombinant expression in heterologous hosts is described and their catalytic activity against polyester substrates is compared. Assays to analyze the enzymatic hydrolysis of synthetic polyesters are evaluated, and a kinetic model describing the enzymatic heterogeneous hydrolysis process is discussed. Structure-function and structure-stability relationships of actinomycete polyester hydrolases are compared based on molecular dynamics simulations and recently solved protein structures. In addition, recent progress in enhancing their activity and thermal stability by random or site-directed mutagenesis is presented.

  6. Amycolatopsis thailandensis sp. nov., a poly(L-lactic acid)-degrading actinomycete, isolated from soil.

    PubMed

    Chomchoei, Atchareeya; Pathom-Aree, Wasu; Yokota, Akira; Kanongnuch, Chartchai; Lumyong, Saisamorn

    2011-04-01

    A novel actinomycete that was capable of degrading poly(l-lactic acid), strain CMU-PLA07(T), was isolated from soil in northern Thailand. Strain CMU-PLA07(T) had biochemical, chemotaxonomic, morphological and physiological properties that were consistent with its classification in the genus Amycolatopsis. 16S rRNA gene sequence analysis showed that the isolate formed a phyletic line within the genus Amycolatopsis. Strain CMU-PLA07(T) was most similar to Amycolatopsis coloradensis IMSNU 22096(T) (99.5 % 16S rRNA gene sequence similarity) and Amycolatopsis alba DSM 44262(T) (99.4 %). However, strain CMU-PLA07(T) was distinguishable from the type strains of species of the genus Amycolatopsis on the basis of DNA-DNA relatedness and phenotypic data. Therefore, strain CMU-PLA07(T) is considered to represent a novel species of the genus Amycolatopsis, for which the name Amycolatopsis thailandensis sp. nov. is proposed. The type strain is CMU-PLA07(T) ( = JCM 16380(T) = BCC 38279(T)).

  7. Actinomycetes from Eucalyptus and their biological activities for controlling Eucalyptus leaf and shoot blight.

    PubMed

    Himaman, Winanda; Thamchaipenet, Arinthip; Pathom-Aree, Wasu; Duangmal, Kannika

    2016-01-01

    In Thailand, Eucalyptus plantations rapidly expand across the country. Leaf and shoot blight caused by Cryptosporiopsis eucalypti, Cylindrocladium sp. and Teratosphaeria destructans is a serious disease in Eucalyptus plantations. In this study, a total of 477 actinomycete strains were successfully isolated from roots and rhizosphere soil of Eucalyptus. Four hundred and thirty nine isolates were classified as streptomycetes and 38 isolates were non-streptomycetes. Among these isolates, 272 (57.0%), 118 (24.7%) and 241 (50.5%) isolates were antagonistic to Cryptosporiopsis eucalypti, Cylindrocladium sp. and Teratosphaeria destructans, respectively. All isolates were tested for their abilities to produce siderophores, indole acetic acid (IAA) and solubilise phosphate. Most isolates (464, 97.3%) produced siderophores. The majority of isolates (345, 72.3%) solubilised phosphate. In addition, almost half of these isolates (237, 49.7%) produced indole acetic acid. Strain EUSKR2S82 which showed the strongest inhibitory effect against all tested fungi with plant growth promoting ability was selected to test with Eucalyptus. This strain could colonize plant roots and increase Eucalyptus roots length. In a detached leaves bioassay, the disease severity of EUSKR2S82-inoculated Eucalyptus leaves was only 30% compared to 95% in the control treatment. The 16S rRNA gene sequence analysis revealed that the strain EUSKR2S82 was related to Streptomyces ramulosus NRRL-B 2714(T) (99.44% similarity). Identification of non-streptomycete isolates using 16S rRNA gene sequences classified them into 9 genera: Actinoallomurus, Actinomadura, Amycolatopsis, Cryptosporangium, Microbispora, Micromonospora, Nocardia, Nonomuraea and Pseudonocardia. It is evident that Eucalyptus tree harbored several genera of actinomycetes. The selected isolate, EUSKR2S82 showed potential as a candidate for biocontrol agent of leaf and shoot blight of Eucalyptus and to promote growth.

  8. Effect of crude extracts of selected actinomycetes on biofilm formation of A. schindleri, M. aci, and B. cereus.

    PubMed

    Saleem, Hafiz Ghulam Murtaza; Aftab, Usman; Sajid, Imran; Abbas, Zaigham; Sabri, Anjum Nasim

    2015-05-01

    Actinomycetes are well known group of gram positive bacteria for their potential to produce antibiotics. This study sought to assess the ability of the selected actinomycetes to control biofilm forming bacteria isolated from different dental plaque samples. On the basis of morphological differences three out of ten different dental plaque bacterial isolates were selected for further study. These isolates were biochemically and genetically characterized and were identified as Acinetobacter schinndleri, Moraxella aci, and Bacillus cereus. Antibiotic resistant profile was measured through disc diffusion method and found that all three isolates were moderately sensitive to ofloxacin and erythromycin and resistant to trimethoprim. Antibacterial activity of ten different Streptomyces strains was assessed through an agar plug and well diffusion method against three dental biofilm forming bacteria. Two Streptomyces strains named as S. erythrogriseus and S. labedae showed good antibacterial activity against Moraxella and Acinetobacter strains. Ability of the four active antibiotic producing strains to inhibit biofilm formation was assessed using microtiter biofilm detection assay. It was found that biofilm forming ability of Acinetobacter and Moraxella was inhibited by S. labedae an antibiotic producing strain, while S. macrosporeus can only inhibit biofilm formation by B. cereus.

  9. Strain shielding inspired re-design of proximal femoral stems for total hip arthroplasty.

    PubMed

    Cilla, Myriam; Checa, Sara; Duda, Georg N

    2017-02-08

    A large number of hip prosthesis with different designs have been developed. However, the influence of hip implant design changes on the strains induced in the bone remains unclear. The purpose of this study is to better understand the mechanics of short stem total hip arthroplasty. Specifically, it investigates whether strain shielding can be avoided by changing implant shape and/or material properties. It is hypothesized that the re-design of existing implant designs can result in further reduction of strain shielding and thus keep bone loss minimal following total hip replacement. Finite element methods were used to compare healthy and implanted models. The local mechanics strains/stresses in the intact and implanted femurs were determined under patient-specific muscle and joint contact forces. Results suggest that small changes in implant geometry and material properties have no major effect on strain shielding. Furthermore, it was found that improvement depends on a dramatic re-design of the original implant design. Whereas the benefit of this strategy of modification of the original geometry of a given short-stemmed hip consists in reduced bone remodeling, care should be taken with regard to long-term bone anchorage and implant fatigue strength. It is also shown that geometrical and material changes have a limited potential in avoiding strain shielding even in short-stemmed implants. Finally, it is suggested that an understanding of the influence of these changes on the strain distribution within the bone can guide in the process of optimizing the current stem designs toward minimal strain shielding effects. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  10. Antibiotic production by actinomycetes: the Janus faces of regulation.

    PubMed

    Cundliffe, Eric

    2006-07-01

    This manuscript reviews some of the common regulatory mechanisms that control antibiotic production in actinomycetes. These ubiquitous bacteria, collectively responsible for the earthy smell of soil, are prolific producers of antibiotics and other secondary metabolites. The content of this review is biased towards the author's current research interests, concerning the action of regulatory gene products that control transcription of antibiotic-biosynthetic genes and the associated involvement of low molecular weight signalling molecules of the gamma-butyrolactone family. As a result, much fertile ground remains unturned particularly in the area of environmental monitoring and responses of actinomycetes to stimuli so perceived. Reviews casting a broader net are cited in the text.

  11. Study of the cellulases produced by three mesophilic actinomycetes grown on bagasse as substrate

    SciTech Connect

    Van Zyl, W.H.

    1985-09-01

    The cellulases that strains of Streptomyces albogrisolus, S. nitrosporeus, and Micromonospora melanosporea produce when grown on untreated ballmilled bagasse were investigated. Optimum conditions for extracellular cellulase production and activity were determined to be growth at pH 6.7-7.4 and 25-35 degrees C for 4-5 days and assay at pH 5.0-6.0 and 45-55 degrees C, respectively. The endoglucanases were thermally stable at 50 degrees C, but the Avicelases had a half-life of approximately 24 hours at this temperature. Nearly half of the endoglucanases and almost all of the Avicelases were absorbed on ballmilled bagasse after 15 minutes incubation at 50 degrees C. The ..beta..-glucosidases were found to be mainly intracellular or cell wall bound. These mesophilic actinomycetes concomitantly produced xylanases and ..beta..-xylosidases with cellulases that, apart from cellobiose and glucose, also release xylose from bagasse. This feature may be advantageous in the commercial application of the enzymes of mesophilic actinomycetes for the saccharification of natural cellulosic substrates.

  12. Development of actinomycetes in brown semidesert soil under low water pressure

    NASA Astrophysics Data System (ADS)

    Zvyagintsev, D. G.; Zenova, G. M.; Sudnitsyn, I. I.; Gracheva, T. A.; Lapygina, E. E.; Napol'skaya, K. R.; Sydnitsyna, A. E.

    2012-07-01

    Under laboratory conditions, the spores of a xerotolerant Streptomyces odorifera strain germinated in brown semidesert soil even at extremely low soil water pressure ( P = -96.4 MPa, -964 atm, a w 0.50); the plantlets increased in length and formed mycelium, on which a new generation of spores was produced (a complete development cycle of the actinomycetes—from a spore to the formation of new spores—passed). The duration of the first cycles of the actinomycetes' development varied from 13 days at P = -27 atm to 57 days at P = -964 atm and was directly proportional to the absolute value of the soil water pressure ( P). In the first cycles of the actinomycetes' development, the rate of increase of the concentration of the germinated spores and mycelium, as well as the logarithms of the mycelium-to-germinated spore concentration ratios, was inversely proportional to the logarithm of P. These relationships indicated that the energy state of the water determined its availability to soil biota and, hence, the activity of its physiological and biochemical processes.

  13. Screening of Marine Actinomycetes from Segara Anakan for Natural Pigment and Hydrolytic Activities

    NASA Astrophysics Data System (ADS)

    Asnani, A.; Ryandini, D.; Suwandri

    2016-02-01

    Marine actinomycetes have become sources of great interest to natural product chemistry due to their new chemical entities and bioactive metabolites. Since April 2010, we have screened actinobacteria from five sites that represent different ecosystems of Segara Anakan lagoon. In this present study we focus on specific isolates, K-2C which covers 1) actinomycetes identification based on morphology observation and 16S rRNA gene; 2) fermentation and isolation of pigment; 3) structure determination of pigment; and 4) hydrolytic enzymes characterization; Methodologies relevant to the studies were implemented accordingly. The results indicated that K-2C was likely Streptomyces fradiae strain RSU15, and the best fermentation medium should contain starch and casein with 21 days of incubation. The isolate has extracellular as well as intracellular pigments. Isolated pigments gave purple color with λmax of 529.00 nm. The pigment was structurally characterized. Interestingly, Streptomyces K-2C was able to produce potential hydrolytic enzymes such as amylase, cellulase, protease, lipase, urease, and nitrate reductase.

  14. Viability of fungal and actinomycetal spores after microwave radiation of building materials.

    PubMed

    Górny, Rafał L; Mainelis, Gediminas; Wlazło, Agnieszka; Niesler, Anna; Lis, Danuta O; Marzec, Stanisław; Siwińska, Ewa; Łudzeń-Izbińska, Beata; Harkawy, Aleksander; Kasznia-Kocot, Joanna

    2007-01-01

    The effects of microwave radiation on viability of fungal and actinomycetal spores growing on agar (medium optimal for growth) as well as on wooden panel and drywall (common building construction/finishing materials) were studied. All materials were incubated at high (97-99%) and low (32-33%) relative humidity to mimic "wet" and "dry" environmental conditions. Two microwave power densities (10 and 60 mW/cm2) and three times of exposure (5, 30, and 60 min) were tested to find the most effective parameters of radiation which could be applied to non-invasive reduction or cleaning of building materials from microbial contaminants. Additionally, a control of the surface temperature during the experiments allowed differentiation between thermal and microwave effect of such radiation. The results showed that the viability of studied microorganisms differed depending on their strains, growth conditions, power density of microwave radiation, time of exposure, and varied according to the applied combination of the two latter elements. The effect of radiation resulting in a decrease of spore viability on "wet" wooden panel and drywall was generally observed at 60 min exposure. Shorter exposure times decreased the viability of fungal spores only, while in actinomycetes colonizing the studied building materials, such radiation caused an opposite (supporting growth) effect.

  15. A Web-Based Platform for Designing Vaccines against Existing and Emerging Strains of Mycobacterium tuberculosis

    PubMed Central

    Dhanda, Sandeep Kumar; Vir, Pooja; Singla, Deepak; Gupta, Sudheer; Kumar, Shailesh

    2016-01-01

    Development of an effective vaccine against drug-resistant Mycobacterium tuberculosis (Mtb) is crucial for saving millions of premature deaths every year due to tuberculosis. This paper describes a web portal developed for assisting researchers in designing vaccines against emerging Mtb strains using traditional and modern approaches. Firstly, we annotated 59 genomes of Mycobacterium species to understand similarity/dissimilarity between tuberculoid, non-tuberculoid and vaccine strains at genome level. Secondly, antigen-based vaccine candidates have been predicted in each Mtb strain. Thirdly, epitopes-based vaccine candidates were predicted/discovered in above antigen-based vaccine candidates that can stimulate all arms of immune system. Finally, a database of predicted vaccine candidates at epitopes as well at antigen level has been developed for above strains. In order to design vaccine against a newly sequenced genome of Mtb strain, server integrates three modules for identification of strain-, antigen-, epitope-specific vaccine candidates. We observed that 103522 unique peptides (9mers) had the potential to induce an antibody response and/or promiscuous binder to MHC alleles and/or have the capability to stimulate T lymphocytes. In summary, this web-portal will be useful for researchers working on designing vaccines against Mtb including drug-resistant strains. Availability: The database is available freely at http://crdd.osdd.net/raghava/mtbveb/. PMID:27096425

  16. Genome Sequence of the Filamentous Actinomycete Kitasatospora viridifaciens

    PubMed Central

    Ramijan, Karina

    2017-01-01

    ABSTRACT The vast majority of antibiotics are produced by filamentous soil bacteria called actinomycetes. We report here the genome sequence of the tetracycline producer “Streptomyces viridifaciens” DSM 40239. Given that this species has the hallmark signatures characteristic of the Kitasatospora genus, we previously proposed to rename this organism Kitasatospora viridifaciens. PMID:28183757

  17. A novel taxonomic marker that discriminates between morphologically complex actinomycetes.

    PubMed

    Girard, Geneviève; Traag, Bjørn A; Sangal, Vartul; Mascini, Nadine; Hoskisson, Paul A; Goodfellow, Michael; van Wezel, Gilles P

    2013-10-23

    In the era when large whole genome bacterial datasets are generated routinely, rapid and accurate molecular systematics is becoming increasingly important. However, 16S ribosomal RNA sequencing does not always offer sufficient resolution to discriminate between closely related genera. The SsgA-like proteins are developmental regulatory proteins in sporulating actinomycetes, whereby SsgB actively recruits FtsZ during sporulation-specific cell division. Here, we present a novel method to classify actinomycetes, based on the extraordinary way the SsgA and SsgB proteins are conserved. The almost complete conservation of the SsgB amino acid (aa) sequence between members of the same genus and its high divergence between even closely related genera provides high-quality data for the classification of morphologically complex actinomycetes. Our analysis validates Kitasatospora as a sister genus to Streptomyces in the family Streptomycetaceae and suggests that Micromonospora, Salinispora and Verrucosispora may represent different clades of the same genus. It is also apparent that the aa sequence of SsgA is an accurate determinant for the ability of streptomycetes to produce submerged spores, dividing the phylogenetic tree of streptomycetes into liquid-culture sporulation and no liquid-culture sporulation branches. A new phylogenetic tree of industrially relevant actinomycetes is presented and compared with that based on 16S rRNA sequences.

  18. The medically important aerobic actinomycetes: epidemiology and microbiology.

    PubMed Central

    McNeil, M M; Brown, J M

    1994-01-01

    The aerobic actinomycetes are soil-inhabiting microorganisms that occur worldwide. In 1888, Nocard first recognized the pathogenic potential of this group of microorganisms. Since then, several aerobic actinomycetes have been a major source of interest for the commercial drug industry and have proved to be extremely useful microorganisms for producing novel antimicrobial agents. They have also been well known as potential veterinary pathogens affecting many different animal species. The medically important aerobic actinomycetes may cause significant morbidity and mortality, in particular in highly susceptible severely immunocompromised patients, including transplant recipients and patients infected with human immunodeficiency virus. However, the diagnosis of these infections may be difficult, and effective antimicrobial therapy may be complicated by antimicrobial resistance. The taxonomy of these microorganisms has been problematic. In recent revisions of their classification, new pathogenic species have been recognized. The development of additional and more reliable diagnostic tests and of a standardized method for antimicrobial susceptibility testing and the application of molecular techniques for the diagnosis and subtyping of these microorganisms are needed to better diagnose and treat infected patients and to identify effective control measures for these unusual pathogens. We review the epidemiology and microbiology of the major medically important aerobic actinomycetes. Images PMID:7923055

  19. Biodiscovery from rare actinomycetes: an eco-taxonomical perspective.

    PubMed

    Kurtböke, D I

    2012-03-01

    Microbial natural products, in particular, the ones produced by the members of the order Actinomycetales, will continue to represent an important route to the discovery of novel classes of bioactive compounds. As a result, the search for and discovery of lesser-known and/or novel actinomycetes is of significant interest to the industry due to a growing need for the development of new and potent therapeutic agents, mainly against drug resistant bacteria. Current advancements in genomics and metagenomics are adding strength to the target-directed search for detection and isolation of bioactive actinomycetes. New discoveries, however, will only stem from a sound understanding and interpretation of knowledge derived from conventional studies conducted since the discovery of streptomycin, on the ecology, taxonomy, physiology and metabolism of actinomycetes, and from a combination of this knowledge with currently available and continuously advancing molecular tools. Such a powerful information platform will then inevitably reveal the whereabouts, taxonomical and chemical identities of previously undetected bioactive actinomycetes including novel species of streptomycetes as potential producers of novel drug candidates.

  20. Strain response of stretchable micro-electrodes: Controlling sensitivity with serpentine designs and encapsulation

    SciTech Connect

    Gutruf, Philipp; Walia, Sumeet; Nur Ali, Md; Sriram, Sharath E-mail: madhu.bhaskaran@gmail.com; Bhaskaran, Madhu E-mail: madhu.bhaskaran@gmail.com

    2014-01-13

    The functionality of flexible electronics relies on stable performance of thin film micro-electrodes. This letter investigates the behavior of gold thin films on polyimide, a prevalent combination in flexible devices. The dynamic behavior of gold micro-electrodes has been studied by subjecting them to stress while monitoring their resistance in situ. The shape of the electrodes was systematically varied to examine resistive strain sensitivity, while an additional encapsulation was applied to characterize multilayer behavior. The realized designs show remarkable tolerance to repetitive strain, demonstrating that curvature and encapsulation are excellent approaches for minimizing resistive strain sensitivity to enable durable flexible electronics.

  1. Antibiotic resistance mechanisms inform discovery: identification and characterization of a novel amycolatopsis strain producing ristocetin.

    PubMed

    Truman, Andrew W; Kwun, Min Jung; Cheng, Jinhua; Yang, Seung Hwan; Suh, Joo-Won; Hong, Hee-Jeon

    2014-10-01

    Discovering new antibiotics is a major scientific challenge, made increasingly urgent by the continued development of resistance in bacterial pathogens. A fundamental understanding of the mechanisms of bacterial antibiotic resistance will be vital for the future discovery or design of new, more effective antibiotics. We have exploited our intimate knowledge of the molecular mechanism of glycopeptide antibiotic resistance in the harmless bacterium Streptomyces coelicolor to develop a new two-step cell wall bioactivity screen, which efficiently identified a new actinomycete strain containing a previously uncharacterized glycopeptide biosynthetic gene cluster. The screen first identifies natural product extracts capable of triggering a generalized cell wall stress response and then specifically selects for glycopeptide antibacterials by assaying for the induction of glycopeptide resistance genes. In this study, we established a diverse natural product extract library from actinomycete strains isolated from locations with widely varying climates and ecologies, and we screened them using the novel two-step bioassay system. The bioassay ultimately identified a single strain harboring the previously unidentified biosynthetic gene cluster for the glycopeptide ristocetin, providing a proof of principle for the effectiveness of the screen. This is the first report of the ristocetin biosynthetic gene cluster, which is predicted to include some interesting and previously uncharacterized enzymes. By focusing on screening libraries of microbial extracts, this strategy provides the certainty that identified producer strains are competent for growth and biosynthesis of the detected glycopeptide under laboratory conditions.

  2. Saccharothrix saharensis sp. nov., an actinomycete isolated from Algerian Saharan soil.

    PubMed

    Boubetra, Dalila; Zitouni, Abdelghani; Bouras, Noureddine; Mathieu, Florence; Lebrihi, Ahmed; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2013-10-01

    The taxonomic position of a novel actinomycete, strain SA152(T), isolated from a sample of Algerian Saharan soil, was determined using a polyphasic taxonomic approach. The strain produced abundant aerial mycelium and fragmented substrate mycelium on most media tested. Chemotaxonomically and phylogenetically, the strain was related to the members of the genus Saccharothrix. Results of 16S rRNA gene sequence comparison revealed that strain SA152(T) shared the highest degree of 16S rRNA gene sequence similarity with Saccharothrix xinjiangensis NBRC 101911(T) (99.3 %) and Saccharothrix texasensis NRRL B-16134(T) (98.9 %). However, DNA-DNA hybridization studies showed only 16.2 % relatedness with S. xinjiangensis DSM 44896(T) and 33.9 % relatedness with S. texasensis DSM 44231(T). Based upon genotypic and phenotypic differences from other members of the genus, a novel species, Saccharothrix saharensis sp. nov., is proposed, with SA152(T) ( = DSM 45456(T) = CCUG 60213(T)) as the type strain.

  3. Streptomyces castaneus sp. nov., a novel actinomycete isolated from the rhizosphere of Peucedanum praeruptorum Dunn.

    PubMed

    Zhou, Shuyu; Li, Zhilei; Bai, Lu; Yan, Kai; Zhao, Junwei; Lu, Chang; Liu, Chongxi; Wang, Xiangjing; Xiang, Wensheng

    2017-01-01

    During an investigation of microbial diversity in medicinal herbs, a novel actinomycete, strain NEAU-QHHV11(T) was isolated from the rhizosphere of Peucedanum praeruptorum Dunn collected from Xianglu Mountain in Heilongjiang Province, northeast China and characterized using a polyphasic approach. The organism was found to have typical characteristics of the genus Streptomyces. Phylogenetic analysis based on 16S rRNA gene sequence also indicated that strain NEAU-QHHV11(T) belongs to the genus Streptomyces and was most closely related to Streptomyces graminilatus NBRC 108882(T) (98.7 % sequence similarity) and Streptomyces turgidiscabies NBRC 16080(T) (98.7 % sequence similarity). The results of DNA-DNA hybridization and some phenotypic characteristics indicated that strain NEAU-QHHV11(T) could be distinguished from its close phylogenetic relatives. Thus, strain NEAU-QHHV11(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces castaneus sp. nov. is proposed. The type strain is NEAU-QHHV11(T) (=CGMCC 4.7235(T) = DSM 100520(T)).

  4. Antibiotic-producing ability by representatives of a newly discovered lineage of actinomycetes.

    PubMed

    Busti, Elena; Monciardini, Paolo; Cavaletti, Linda; Bamonte, Ruggiero; Lazzarini, Ameriga; Sosio, Margherita; Donadio, Stefano

    2006-03-01

    The discovery of new antibiotics and other bioactive microbial metabolites continues to be an important objective in new drug research. Since extensive screening has led to the discovery of thousands of bioactive microbial molecules, new approaches must be taken in order to reduce the probability of rediscovering known compounds. The authors have recently isolated slow-growing acidophiles belonging to the novel genera Catenulispora and Actinospica within the order Actinomycetales. These strains, which likely belong to a new suborder, grow as filamentous mycelia, have a genome size around 8 Mb, and produce antimicrobial activities. In addition, a single strain harbours simultaneously genes encoding type I and type II polyeketide synthases, as well as non-ribosomal peptide synthetases. The metabolite produced by one strain was identified as a previously reported dimeric isochromanequinone. In addition, at least the Catenulispora strains appear globally distributed, since a PCR-specific signal could be detected in a significant fraction of acidic soils from different continents, and similar strains have been independently isolated from an Australian soil (Jospeh et al., Appl Environ Microbiol 69, 7210-7215, 2003). Thus, these previously uncultured actinomycetes share several features with Streptomyces and related antibiotic-producing genera, and represent a promising source of novel antibiotics.

  5. Design and Testing of the Strain Transducer for Measuring Deformations of Pipelines Operating in the Mining-deformable Ground Environment

    NASA Astrophysics Data System (ADS)

    Gawedzki, Waclaw; Tarnowski, Jerzy

    2015-10-01

    Design and laboratory test results of the strain transducer intended for monitoring and assessing stress states of pipelines sited in mining areas are presented in this paper. This transducer allows measuring strains of pipelines subjected to external forces - being the mining operations effect. Pipeline strains can have a direct influence on a tightness loss and penetration of the transported fluid into the environment. The original strain gauge transducer was proposed for performing measurements of strains. It allows measuring circumferential strains and determining the value and direction of the main longitudinal strain. This strain is determined on the basis of measuring component longitudinal strains originating from axial forces and the resultant bending moment. The main purpose of investigations was the experimental verification of the possibility of applying the strain transducer for measuring strains of polyethylene pipelines. The obtained results of the transducer subjected to influences of tensile and compression forces are presented and tests of relaxation properties of polyethylene are performed.

  6. Biodegradation of anthracene by a novel actinomycete, Microbacterium sp. isolated from tropical hydrocarbon-contaminated soil.

    PubMed

    Salam, Lateef B; Obayori, Oluwafemi S; Olatoye, Nojeem O

    2014-01-01

    A novel anthracene-degrading Gram-positive actinomycete, Microbacterium sp. strain SL10 was isolated from a hydrocarbon-contaminated soil at a mechanical engineering workshop in Lagos, Nigeria. The polluted soil had an unusually high total hydrocarbon content of 157 g/kg and presence of various heavy metals. The isolate tolerated salt concentration of more than 4%. It resisted cefotaxime, streptomycin and ciprofloxacin, but susceptible to meropenem, linezolid and vancomycin. The isolate exhibited growth rate and doubling time of 0.82 days(-1) and 0.84 days, respectively on anthracene. It degraded 57.5 and 90.12% of anthracene within 12 and 21 days, respectively while the rate of anthracene utilization by the isolate was 4.79 mg l(-1) d(-1). To the best of our knowledge, this is the first report of isolation and characterization of anthracene-degrading Microbacterium sp.

  7. Actinopolyspora saharensis sp. nov., a novel halophilic actinomycete isolated from a Saharan soil of Algeria.

    PubMed

    Meklat, Atika; Bouras, Noureddine; Zitouni, Abdelghani; Mathieu, Florence; Lebrihi, Ahmed; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2013-04-01

    A novel halophilic actinomycete, strain H32(T), was isolated from a Saharan soil sample collected in El-Oued province, south Algeria. The isolate was characterized by means of polyphasic taxonomy. Optimal growth was determined to occur at 28-32 °C, pH 6.0-7.0 and in the presence of 15-25 % (w/v) NaCl. The strain was observed to produce abundant aerial mycelium, which formed long chains of rod-shaped spores at maturity, and fragmented substrate mycelium. The cell wall was determined to contain meso-diaminopimelic acid and the characteristic whole-cell sugars were arabinose and galactose. The predominant menaquinones were found to be MK-10(H4) and MK-9(H4). The predominant cellular fatty acids were determined to be anteiso C17:0, iso-C15:0 and iso-C16:0. The diagnostic phospholipid detected was phosphatidylcholine. Phylogenetic analyses based on the 16S rRNA gene sequence showed that this strain formed a distinct phyletic line within the radiation of the genus Actinopolyspora. The 16S rRNA gene sequence similarity indicated that strain H32(T) was most closely related to 'Actinopolyspora algeriensis' DSM 45476(T) (98.8 %) and Actinopolyspora halophila DSM 43834(T) (98.5 %). Furthermore, the result of DNA-DNA hybridization between strain H32(T) and the type strains 'A. algeriensis' DSM 45476(T), A. halophila DSM 43834(T) and Actinopolyspora mortivallis DSM 44261(T) demonstrated that this isolate represents a different genomic species in the genus Actinopolyspora. Moreover, the physiological and biochemical data allowed the differentiation of strain H32(T) from its closest phylogenetic neighbours. Therefore, it is proposed that strain H32(T) represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora saharensis sp. nov. is proposed. The type strain is H32(T) (=DSM 45459(T)=CCUG 62966(T)).

  8. Actinoallomurus bryophytorum sp. nov., an endophytic actinomycete isolated from moss (Bryophyta).

    PubMed

    Li, Chuang; Wang, Haiyan; Jin, Pinjiao; Zheng, Weijia; Chu, Liyang; Liu, Chongxi; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

    2015-08-01

    A novel endophytic actinomycete, strain NEAU-TX1-15(T), was isolated from moss, collected from Wuchang, Heilongjiang province, north China. A polyphasic taxonomic study was carried out to establish the status of strain NEAU-TX1-15(T). Morphological and chemotaxonomic properties of strain NEAU-TX1-15(T) are consistent with the description of the genus Actinoallomurus. Strain NEAU-TX1-15(T) was observed to form short spiral or looped spore chains on aerial hyphae. The cell wall peptidoglycan was found to contain lysine and meso-diaminopimelic acid. The major menaquinones were identified as MK-9(H6) and MK-9(H8). The only phospholipid identified was phosphatidylglycerol. The major fatty acid was identified as iso-C16:0. Analysis of the 16S rRNA gene sequence supports the assignment of the novel strain to the genus Actinoallomurus, as it exhibits 99.2 % gene sequence similarity to that of Actinoallomurus yoronensis NBRC 103686(T). However, the low level of DNA-DNA relatedness allowed the strain to be differentiated from its close relative. Moreover, strain NEAU-TX1-15(T) could also be differentiated from A. yoronensis NBRC 103686(T) and other Actinoallomurus species showing high 16S rRNA gene sequence similarity (>98.0 %) by cultural and physiological characteristics. Therefore, the combination of phenotypic and chemotaxonomic data, and the DNA-DNA hybridization value, indicated that strain NEAU-TX1-15(T) represents a novel species of the genus Actinoallomurus for which the name Actinoallomurus bryophytorum sp. nov. is proposed. The type strain is NEAU-TX1-15(T) (=CGMCC 4.7200(T) = JCM 30340(T)).

  9. Design, Evaluation and Experimental Effort Toward Development of a High Strain Composite Wing for Navy Aircraft

    NASA Technical Reports Server (NTRS)

    Bruno, Joseph; Libeskind, Mark

    1990-01-01

    This design development effort addressed significant technical issues concerning the use and benefits of high strain composite wing structures (Epsilon(sub ult) = 6000 micro-in/in) for future Navy aircraft. These issues were concerned primarily with the structural integrity and durability of the innovative design concepts and manufacturing techniques which permitted a 50 percent increase in design ultimate strain level (while maintaining the same fiber/resin system) as well as damage tolerance and survivability requirements. An extensive test effort consisting of a progressive series of coupon and major element tests was an integral part of this development effort, and culminated in the design, fabrication and test of a major full-scale wing box component. The successful completion of the tests demonstrated the structural integrity, durability and benefits of the design. Low energy impact testing followed by fatigue cycling verified the damage tolerance concepts incorporated within the structure. Finally, live fire ballistic testing confirmed the survivability of the design. The potential benefits of combining newer/emerging composite materials and new or previously developed high strain wing design to maximize structural efficiency and reduce fabrication costs was the subject of subsequent preliminary design and experimental evaluation effort.

  10. Effect of nickel titanium file design on the root surface strain and apical microcracks.

    PubMed

    Jamleh, Ahmed; Adorno, Carlos G; Ebihara, Arata; Suda, Hideaki

    2016-04-01

    The aim of this study was to determine the effect of nickel titanium file design on the root surface strain generated and apical microcracks caused during canal shaping. Thirty-three mandibular incisors were distributed into LightSpeed X, FlexMaster and a control group. A strain gauge was fixed apically on the proximal root surface to determine the maximum strain during canal shaping. Except for the control group, all root canals were enlarged to size 50. Images were taken after removing the apical 1 and 2 mm of the root end. Mean maximum strain values and presence of microcracks were statistically compared using the t-test and chi-square test, respectively. During canal shaping, the strain increased cumulatively with mean maximum strains of 808.2 ± 228.8 and 525.1 ± 168.9 microstrain in LightSpeed X and FlexMaster, respectively (P = 0.004). Both systems caused comparable microcracks. Although LightSpeed X produced higher maximum strain, no difference in microcrack development was found between both systems.

  11. Unusual multifocal granulomatous disease caused by actinomycetous bacteria in a nestling Derbyan parrot (Psittacula derbiana).

    PubMed

    Park, F J; Jaensch, S

    2009-01-01

    A nestling Derbyan parrot (Psittacula derbiana) was presented with unusual subcutaneous swellings of the thigh regions, and poor growth. Histological examination revealed actinomycetous bacteria associated with multifocal systemic granulomas. The clinical and pathological findings of the case are presented, and some relevant aspects of actinomycetous bacterial infections in mammals and birds are discussed. Although granulomatous disease is encountered at times in avian species, the actinomycetous bacteria (Nocardia and Actinomyces spp.) have rarely been reported in association with multifocal granulomatous disease in birds.

  12. Novel design of dual-core microstructured fiber with enhanced longitudinal strain sensitivity

    NASA Astrophysics Data System (ADS)

    Szostkiewicz, Lukasz; Tenderenda, T.; Napierala, M.; Szymański, M.; Murawski, M.; Mergo, P.; Lesiak, P.; Marc, P.; Jaroszewicz, L. R.; Nasilowski, T.

    2014-05-01

    Constantly refined technology of manufacturing increasingly complex photonic crystal fibers (PCF) leads to new optical fiber sensor concepts. The ways of enhancing the influence of external factors (such as hydrostatic pressure, temperature, acceleration) on the fiber propagating conditions are commonly investigated in literature. On the other hand longitudinal strain analysis, due to the calculation difficulties caused by the three dimensional computation, are somehow neglected. In this paper we show results of such a 3D numerical simulation and report methods of tuning the fiber strain sensitivity by changing the fiber microstructure and core doping level. Furthermore our approach allows to control whether the modes' effective refractive index is increasing or decreasing with strain, with the possibility of achieving zero strain sensitivity with specific fiber geometries. The presented numerical analysis is compared with experimental results of the fabricated fibers characterization. Basing on the aforementioned methodology we propose a novel dual-core fiber design with significantly increased sensitivity to longitudinal strain for optical fiber sensor applications. Furthermore the reported fiber satisfies all conditions necessary for commercial applications like good mode matching with standard single-mode fiber, low confinement loss and ease of manufacturing with the stack-and-draw technique. Such fiber may serve as an integrated Mach-Zehnder interferometer when highly coherent source is used. With the optimization of single mode transmission to 850 nm, we propose a VCSEL source to be used in order to achieve a low-cost, reliable and compact strain sensing transducer.

  13. Isolation strategies of marine-derived actinomycetes from sponge and sediment samples.

    PubMed

    Hameş-Kocabaş, E Esin; Uzel, Ataç

    2012-03-01

    During the last two decades, discoveries of new members of actinomycetes and novel metabolites from marine environments have drawn attention to such environments, such as sediment and sponge. For the successful isolation of actinomycetes from marine environments, many factors including the use of enrichment and pre-treatment techniques, and the selection of growth media and antibiotic supplements should be taken into account. High-throughput cultivation is an innovative technique that mimics nature, eliminates undesired, fast-growing bacteria and creates suitable conditions for rare, slow-growing actinomycetes. This review comprehensively evaluates the traditional and innovative techniques and strategies used for the isolation of actinomycetes from marine sponge and sediment samples.

  14. The structural-functional organization of thermotolerant complexes of actinomycetes in desert and volcanic soils

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Kurapova, A. I.; Lysenko, A. M.; Zvyagintsev, D. G.

    2009-05-01

    It has been found that the number of thermotolerant actinomycetes in strongly heated soils of deserts and volcanic regions is comparable to or exceeds the number of mesophilic actinomycetes. Among the latter group, streptomyces usually predominate; among thermotolerant actinomycetes, representatives of the Micromonospora, Streptosporangium, Actinomadura, Saccharopolyspora, Microtetraspora, and Microbispora genera are identified. Thermotolerant actinomycetes display the full cycle of their development in these soils. The method of fluorescent in situ hybridization has made it possible to determine that mycelial forms predominate among the metabolically active representatives of Actinobacteria; their portion increases with the rise in the temperature of soil incubation.

  15. Biogenic synthesis of metal nanoparticles from actinomycetes: biomedical applications and cytotoxicity.

    PubMed

    Golinska, Patrycja; Wypij, Magdalena; Ingle, Avinash P; Gupta, Indarchand; Dahm, Hanna; Rai, Mahendra

    2014-10-01

    Biogenic synthesis of metal nanoparticles has been well proved by using bacteria, fungi, algae, actinomycetes, plants, etc. Among the different microorganisms used for the synthesis of metal nanoparticles, actinomycetes are less known. Although, there are reports, which have shown that actinomycetes are efficient candidates for the production of metal nanoparticles both intracellularly and extracellularly. The nanoparticles synthesized by the members of actinomycetes present good polydispersity and stability and possess significant biocidal activities against various pathogens. The present review focuses on biological synthesis of metal nanoparticles and their application in medicine. In addition, the toxicity of these biogenic metal nanoparticles to human beings and environment has also been discussed.

  16. Actinopolyspora righensis sp. nov., a novel halophilic actinomycete isolated from Saharan soil in Algeria.

    PubMed

    Meklat, Atika; Bouras, Noureddine; Zitouni, Abdelghani; Mathieu, Florence; Lebrihi, Ahmed; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2013-09-01

    A novel halophilic actinomycete strain, H23(T), was isolated from a Saharan soil sample collected in Djamâa (Oued Righ region), El-Oued province, South Algeria. Strain H23(T) was identified as a member of the genus Actinopolyspora by a polyphasic approach. Phylogenetic analysis showed that strain H23(T) had 16S rRNA gene sequence similarities ranging from 97.8 % (Actinopolyspora xinjiangensis TRM 40136(T)) to 94.8 % (Actinopolyspora mortivallis DSM 44261(T)). The strain grew optimally at pH 6.0-7.0, 28-32 °C and in the presence of 15-25 % (w/v) NaCl. The substrate mycelium was well developed and fragmented with age. The aerial mycelium produced long, straight or flexuous spore chains with non-motile, smooth-surfaced and rod-shaped spores. Strain H23(T) had MK-10 (H4) and MK-9 (H4) as the predominant menaquinones. The whole micro-organism hydrolysates mainly consisted of meso-diaminopimelic acid, galactose and arabinose. The diagnostic phospholipid detected was phosphatidylcholine. The major cellular fatty acids were anteiso-C17:0 (37.4 %), iso-C17:0 (14.8 %), iso-C15:0 (14.2 %), and iso-C16:0 (13.9 %). The genotypic and phenotypic data show that the strain represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora righensis sp. nov. is proposed, with the type strain H23(T) (=DSM 45501(T) = CCUG 63368(T) = MTCC 11562(T)).

  17. Nonomuraea flavida sp. nov., a novel species of soil actinomycete isolated from Aconitum napellus rhizosphere.

    PubMed

    Chen, Shaofeng; Shi, Jindi; Li, Dan; Wu, Yingying; Huang, Yaojian

    2015-11-01

    A novel actinomycete strain, YN-5-1T, isolated from the rhizosphere soil of a medicinal plant, Aconitum napellus, was characterized by a polyphasic approach to determine its taxonomic position. The strain showed highest 16S rRNA gene sequence similarities of 97.3, 97.2 and 97.1 % to Nonomuraea turkmeniaca DSM 43926T, Nonomuraea ferruginea DSM 43553T and Nonomuraea candida DSM 45086T, respectively. A wide range of genotypic and phenotypic characteristics, as well as levels of DNA-DNA relatedness between strain YN-5-1T and N. turkmeniaca DSM 43926T (57.46 %), N. ferruginea DSM 43553T (53.50 %) and N. candida DSM 45086T (48.80 %), distinguished the novel isolate from its closest phylogenetic neighbours. The morphological characteristics of strain YN-5-1T were typical of the genus Nonomuraea. Chemotaxonomic characteristics, such as diagnostic diamino acid of the peptidoglycan, whole-cell sugars, phospholipid type, major menaquinone and major fatty acids, further supported the assignment of strain YN-5-1T to the genus Nonomuraea. The G+C content of the genomic DNA was 72.1 mol%. Based on the above data, strain YN-5-1T is considered to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea flavida sp. nov. is proposed. The type strain is YN-5-1T ( = CCTCC AB 2012909T = KCTC 29143T).

  18. Strain-Based Design Methodology of Large Diameter Grade X80 Linepipe

    SciTech Connect

    Lower, Mark D.

    2014-04-01

    Continuous growth in energy demand is driving oil and natural gas production to areas that are often located far from major markets where the terrain is prone to earthquakes, landslides, and other types of ground motion. Transmission pipelines that cross this type of terrain can experience large longitudinal strains and plastic circumferential elongation as the pipeline experiences alignment changes resulting from differential ground movement. Such displacements can potentially impact pipeline safety by adversely affecting structural capacity and leak tight integrity of the linepipe steel. Planning for new long-distance transmission pipelines usually involves consideration of higher strength linepipe steels because their use allows pipeline operators to reduce the overall cost of pipeline construction and increase pipeline throughput by increasing the operating pressure. The design trend for new pipelines in areas prone to ground movement has evolved over the last 10 years from a stress-based design approach to a strain-based design (SBD) approach to further realize the cost benefits from using higher strength linepipe steels. This report presents an overview of SBD for pipelines subjected to large longitudinal strain and high internal pressure with emphasis on the tensile strain capacity of high-strength microalloyed linepipe steel. The technical basis for this report involved engineering analysis and examination of the mechanical behavior of Grade X80 linepipe steel in both the longitudinal and circumferential directions. Testing was conducted to assess effects on material processing including as-rolled, expanded, and heat treatment processing intended to simulate coating application. Elastic-plastic and low-cycle fatigue analyses were also performed with varying internal pressures. Proposed SBD models discussed in this report are based on classical plasticity theory and account for material anisotropy, triaxial strain, and microstructural damage effects

  19. Large-scale bi-level strain design approaches and mixed-integer programming solution techniques.

    PubMed

    Kim, Joonhoon; Reed, Jennifer L; Maravelias, Christos T

    2011-01-01

    The use of computational models in metabolic engineering has been increasing as more genome-scale metabolic models and computational approaches become available. Various computational approaches have been developed to predict how genetic perturbations affect metabolic behavior at a systems level, and have been successfully used to engineer microbial strains with improved primary or secondary metabolite production. However, identification of metabolic engineering strategies involving a large number of perturbations is currently limited by computational resources due to the size of genome-scale models and the combinatorial nature of the problem. In this study, we present (i) two new bi-level strain design approaches using mixed-integer programming (MIP), and (ii) general solution techniques that improve the performance of MIP-based bi-level approaches. The first approach (SimOptStrain) simultaneously considers gene deletion and non-native reaction addition, while the second approach (BiMOMA) uses minimization of metabolic adjustment to predict knockout behavior in a MIP-based bi-level problem for the first time. Our general MIP solution techniques significantly reduced the CPU times needed to find optimal strategies when applied to an existing strain design approach (OptORF) (e.g., from ∼10 days to ∼5 minutes for metabolic engineering strategies with 4 gene deletions), and identified strategies for producing compounds where previous studies could not (e.g., malate and serine). Additionally, we found novel strategies using SimOptStrain with higher predicted production levels (for succinate and glycerol) than could have been found using an existing approach that considers network additions and deletions in sequential steps rather than simultaneously. Finally, using BiMOMA we found novel strategies involving large numbers of modifications (for pyruvate and glutamate), which sequential search and genetic algorithms were unable to find. The approaches and solution

  20. Diversity of culturable nocardioform actinomycetes from wastewater treatment plants in Spain and their role in the biodegradability of aromatic compounds.

    PubMed

    Soler, Albert; García-Hernández, Jorge; Zornoza, Andrés; Alonso, José Luis

    2017-03-06

    Currently, municipal and industrial wastewater treatment plants (WWTPs) are mainly focusing on reduction of biological oxygen demand and on the removal of nutrients. However, there are microorganisms that interfere with the process. In this environment, there is a large diversity of microorganisms that have not been studied in detail and that could provide real and practical solutions to the foaming problems. Among such microorganisms, Gram-positive actinomycete bacteria are of special interest because they are known for producing secondary metabolites as well as chemically diverse compounds and for their capacity to degrade recalcitrant pollutants. Three different media were chosen to isolate actinomycetes from 28 WWTPs in Spain. A total of 189 activated sludge samples were collected; 126 strains were isolated and identified to belong to 1 suborder, i.e. Corynebacterineae, and 7 genera, i.e. Corynebacterium, Dietzia, Gordonia, Mycobacterium, Rhodococcus, Tsukamurella and Williamsia. Furthermore, 71 strains were capable of biodegrading at least 1 aromatic product, and that 27 of them amplified for catA gene. The results of this research help us understand the complexity of the foam-forming microbial populations in Spain and it shows that WWTPs can be a good source of microorganisms that can degrade phenol or naphthalene.

  1. Comparative analysis of oligonucleotide primers for high-throughput screening of genes encoding adenylation domains of nonribosomal peptide synthetases in actinomycetes.

    PubMed

    Bakal, Tomas; Goo, Kian-Sim; Najmanova, Lucie; Plhackova, Kamila; Kadlcik, Stanislav; Ulanova, Dana

    2015-11-01

    In the biosynthesis of diverse natural bioactive products the adenylation domains (ADs) of nonribosomal peptide synthetases select specific precursors from the cellular pool and activate them for further incorporation into the scaffold of the final compound. Therefore, the drug discovery programs employing PCR-based screening studies of microbial collections or metagenomic libraries often use AD-coding genes as markers of relevant biosynthetic gene clusters. However, due to significant sequence diversity of ADs, the conventional approach using only one primer pair in a single screening experiment could be insufficient for maximal coverage of AD abundance. In this study, the widely used primer pair A3F/A7R was compared with the newly designed aa194F/aa413R one by 454 pyrosequencing of two sets of actinomycete strains from highly dissimilar environments: subseafloor sediments and forest soil. Individually, none of the primer pairs was able to cover the overall diversity of ADs. However, due to slightly shifted specificity of the primer pairs, the total number and diversity of identified ADs were noticeably extended when both primer pairs were used in a single assay. Additionally, the efficiency of AD detection by different primer combinations was confirmed on the model of Salinispora tropica genomic DNA of known sequence.

  2. Structural synthetic biotechnology: from molecular structure to predictable design for industrial strain development.

    PubMed

    Chen, Zhen; Wilmanns, Matthias; Zeng, An-Ping

    2010-10-01

    The future of industrial biotechnology requires efficient development of highly productive and robust strains of microorganisms. Present praxis of strain development cannot adequately fulfill this requirement, primarily owing to the inability to control reactions precisely at a molecular level, or to predict reliably the behavior of cells upon perturbation. Recent developments in two areas of biology are changing the situation rapidly: structural biology has revealed details about enzymes and associated bioreactions at an atomic level; and synthetic biology has provided tools to design and assemble precisely controllable modules for re-programming cellular metabolic circuitry. However, because of different emphases, to date, these two areas have developed separately. A linkage between them is desirable to harness their concerted potential. We therefore propose structural synthetic biotechnology as a new field in biotechnology, specifically for application to the development of industrial microbial strains.

  3. Nocardia halotolerans sp. nov., a halotolerant actinomycete isolated from saline soil.

    PubMed

    Moshtaghi Nikou, Mahdi; Ramezani, Mohaddaseh; Ali Amoozegar, Mohammad; Rasooli, Mehrnoosh; Harirchi, Sharareh; Shahzadeh Fazeli, Seyed Abolhasan; Schumann, Peter; Spröer, Cathrin; Ventosa, Antonio

    2015-09-01

    A novel halotolerant actinomycete, strain Chem15(T), was isolated from soil around Inche-Broun hypersaline wetland; its taxonomic position was determined based on a polyphasic approach. Strain Chem15(T) was strictly aerobic and tolerated NaCl up to 12.5%. The optimum temperature and pH for growth were 28-30 °C and pH 7.0-7.5, respectively. The cell wall of strain Chem15(T) contained meso-diaminopimelic acid as diamino acid and galactose, arabinose and ribose as whole-cell sugars. The major phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The cellular fatty acids profile consisted of C16 : 0, iso-C18 : 0, C18 : 0 10-methyl and C18 : 1ω9c, and the major respiratory quinone was MK-8(H4cycl). The G+C content of the genomic DNA was 68.0 mol%. The novel strain constituted a distinct phyletic line within the genus Nocardia, based on 16S rRNA gene sequence analysis, and was closely associated with Nocardia sungurluensis DSM 45714(T) and Nocardia alba DSM 44684(T) (98.2 and 98.1% 16S rRNA gene sequence similarity, respectively). However DNA-DNA relatedness and phenotypic data demonstrated that strain Chem15(T) was clearly different from closely related species of the genus Nocardia. It is concluded that the organism should be classified as a representative of a novel species of the genus Nocardia, for which the name Nocardia halotolerans sp. nov. is proposed. The type strain is Chem15(T) ( = IBRC-M 10490(T) = LMG 28544(T)).

  4. Migration and strains induced by different designs of force-closed stems for THA☆

    PubMed Central

    Griza, Sandro; Gomes, Luiz Sérgio Marcelino; Cervieri, André; Strohaecker, Telmo Roberto

    2015-01-01

    Objectives Subtle differences in stem design can result in different mechanical responses of the total hip arthroplasty. Tests measuring migration of the stem relative to the femur, as well as the strains in the cement mantle and on the femur can detect different mechanical behavior between stems. Methods In this article, conical, double and triple tapered stems were implanted in composite femurs and subjected to static and cyclic loads. Stems differed mainly on taper angle, calcar radius and proximal stiffness. Stem migration and strains on the femur and in the cement mantle were achieved. Results Significant differences (p < 0.05) were noted in the permanent rotation between double and triple tapers, in the strains on the proximal medial femur between triple and both conical and double tapers, and in the strains on the lateral proximal femur between double tapers and both conical and triple tapers. Conclusion The proposed mechanical tests were able to detect significant differences in the behavior of these resembling stems. Stem proximal stiffness and the calcar radius of the stem influence its rotational stability and the strain transmission to the femur. PMID:27218081

  5. Multiscale Strain Analysis of Tissue Equivalents Using a Custom-Designed Biaxial Testing Device

    PubMed Central

    Bell, B.J.; Nauman, E.; Voytik-Harbin, S.L.

    2012-01-01

    Mechanical signals transferred between a cell and its extracellular matrix play an important role in regulating fundamental cell behavior. To further define the complex mechanical interactions between cells and matrix from a multiscale perspective, a biaxial testing device was designed and built. Finite element analysis was used to optimize the cruciform specimen geometry so that stresses within the central region were concentrated and homogenous while minimizing shear and grip effects. This system was used to apply an equibiaxial loading and unloading regimen to fibroblast-seeded tissue equivalents. Digital image correlation and spot tracking were used to calculate three-dimensional strains and associated strain transfer ratios at macro (construct), meso, matrix (collagen fibril), cell (mitochondria), and nuclear levels. At meso and matrix levels, strains in the 1- and 2-direction were statistically similar throughout the loading-unloading cycle. Interestingly, a significant amplification of cellular and nuclear strains was observed in the direction perpendicular to the cell axis. Findings indicate that strain transfer is dependent upon local anisotropies generated by the cell-matrix force balance. Such multiscale approaches to tissue mechanics will assist in advancement of modern biomechanical theories as well as development and optimization of preconditioning regimens for functional engineered tissue constructs. PMID:22455913

  6. Simplified sensor design for temperature-strain discrimination using fiber Bragg gratings embedded in laminated composites

    NASA Astrophysics Data System (ADS)

    Rodriguez-Cobo, L.; Marques, A. T.; Lopez-Higuera, J. M.; Santos, J. L.; Frazão, O.

    2013-05-01

    Several easy-to-manufacture designs based on a pair of Fiber Bragg Gratings structure embedded in Carbon Fiber Reinforced Plastic (CFRP) have been explored. These smart composites can be used for strain and temperature discrimination. A Finite Elements Analysis and Matlab software were used to study the mechanical responses and its optical behaviors. The results exhibited different sensitivity and using a matrix method it is possible to compensate the thermal drift in a real application keeping a simple manufacture process.

  7. [Secondary Metabolites from Marine Microorganisms. I. Secondary Metabolites from Marine Actinomycetes].

    PubMed

    Orlova, T I; Bulgakova, V G; Polin, A N

    2015-01-01

    Review represents data on new active metabolites isolated from marine actinomycetes published in 2007 to 2014. Marine actinomycetes are an unlimited source of novel secondary metabolites with various biological activities. Among them there are antibiotics, anticancer compounds, inhibitors of biochemical processes.

  8. Characterization and phylogenetic analysis of novel polyene type antimicrobial metabolite producing actinomycetes from marine sediments: Bay of Bengal India

    PubMed Central

    Valan, Arasu M; Asha, KRT; Duraipandiyan, V; Ignacimuthu, S; Agastian, P

    2012-01-01

    Objective To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andrapradesh coast of India. Methods Antagonistic actinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1% glucose used as a base for primary screening. Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level. Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method. Results Among the 210 actinomycetes, 64.3% exhibited activity against Gram positive bacteria, 48.5 % showed activity towards Gram negative bacteria, 38.8% exhibited both Gram positive and negative bacteria and 80.85 % isolates revealed significant antifungal activity. However, five isolates AP-5, AP-18, AP-41 and AP-70 showed significant antimicrobial activity. The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates. Sequencing analysis indicated that the isolates shared 98.5%-99.8% sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons. The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30°Cfor five days. The antimicrobial activity was assessed using broth micro dilution technique. Each of the culture extracts from these five strains showed a typical polyene-like property. The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Curvularia lunata were 67.5 and 125.0 µg/mL, respectively. Conclusions It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi. PMID:23569851

  9. In Vitro and In Vivo Plant Growth Promoting Activities and DNA Fingerprinting of Antagonistic Endophytic Actinomycetes Associates with Medicinal Plants.

    PubMed

    Passari, Ajit Kumar; Mishra, Vineet Kumar; Gupta, Vijai Kumar; Yadav, Mukesh Kumar; Saikia, Ratul; Singh, Bhim Pratap

    2015-01-01

    Endophytic actinomycetes have shown unique plant growth promoting as well as antagonistic activity against fungal phytopathogens. In the present study forty-two endophytic actinomycetes recovered from medicinal plants were evaluated for their antagonistic potential and plant growth-promoting abilities. Twenty-two isolates which showed the inhibitory activity against at least one pathogen were subsequently tested for their plant-growth promoting activities and were compared genotypically using DNA based fingerprinting, including enterobacterial repetitive intergenic consensus (ERIC) and BOX repetitive elements. Genetic relatedness based on both ERIC and BOX-PCR generates specific patterns corresponding to particular genotypes. Exponentially grown antagonistic isolates were used to evaluate phosphate solubilization, siderophores, HCN, ammonia, chitinase, indole-3-acetic acid production, as well as antifungal activities. Out of 22 isolates, the amount of indole-3-acetic acid (IAA) ranging between 10-32 μg/ml was produced by 20 isolates and all isolates were positive for ammonia production ranging between 5.2 to 54 mg/ml. Among 22 isolates tested, the amount of hydroxamate-type siderophores were produced by 16 isolates ranging between 5.2 to 36.4 μg/ml, while catechols-type siderophores produced by 5 isolates ranging from 3.2 to 5.4 μg/ml. Fourteen isolates showed the solubilisation of inorganic phosphorous ranging from 3.2 to 32.6 mg/100ml. Chitinase and HCN production was shown by 19 and 15 different isolates, respectively. In addition, genes of indole acetic acid (iaaM) and chitinase (chiC) were successively amplified from 20 and 19 isolates respectively. The two potential strains Streptomyces sp. (BPSAC34) and Leifsonia xyli (BPSAC24) were tested in vivo and improved a range of growth parameters in chilli (Capsicum annuum L.) under greenhouse conditions. This study is the first published report that actinomycetes can be isolated as endophytes from within these

  10. In Vitro and In Vivo Plant Growth Promoting Activities and DNA Fingerprinting of Antagonistic Endophytic Actinomycetes Associates with Medicinal Plants

    PubMed Central

    Passari, Ajit Kumar; Mishra, Vineet Kumar; Gupta, Vijai Kumar; Yadav, Mukesh Kumar; Saikia, Ratul; Singh, Bhim Pratap

    2015-01-01

    Endophytic actinomycetes have shown unique plant growth promoting as well as antagonistic activity against fungal phytopathogens. In the present study forty-two endophytic actinomycetes recovered from medicinal plants were evaluated for their antagonistic potential and plant growth-promoting abilities. Twenty-two isolates which showed the inhibitory activity against at least one pathogen were subsequently tested for their plant-growth promoting activities and were compared genotypically using DNA based fingerprinting, including enterobacterial repetitive intergenic consensus (ERIC) and BOX repetitive elements. Genetic relatedness based on both ERIC and BOX-PCR generates specific patterns corresponding to particular genotypes. Exponentially grown antagonistic isolates were used to evaluate phosphate solubilization, siderophores, HCN, ammonia, chitinase, indole-3-acetic acid production, as well as antifungal activities. Out of 22 isolates, the amount of indole-3-acetic acid (IAA) ranging between 10–32 μg/ml was produced by 20 isolates and all isolates were positive for ammonia production ranging between 5.2 to 54 mg/ml. Among 22 isolates tested, the amount of hydroxamate-type siderophores were produced by 16 isolates ranging between 5.2 to 36.4 μg/ml, while catechols-type siderophores produced by 5 isolates ranging from 3.2 to 5.4 μg/ml. Fourteen isolates showed the solubilisation of inorganic phosphorous ranging from 3.2 to 32.6 mg/100ml. Chitinase and HCN production was shown by 19 and 15 different isolates, respectively. In addition, genes of indole acetic acid (iaaM) and chitinase (chiC) were successively amplified from 20 and 19 isolates respectively. The two potential strains Streptomyces sp. (BPSAC34) and Leifsonia xyli (BPSAC24) were tested in vivo and improved a range of growth parameters in chilli (Capsicum annuum L.) under greenhouse conditions. This study is the first published report that actinomycetes can be isolated as endophytes from within these

  11. Genomic Libraries and a Host Strain Designed for Highly Efficient Two-Hybrid Selection in Yeast

    PubMed Central

    James, P.; Halladay, J.; Craig, E. A.

    1996-01-01

    The two-hybrid system is a powerful technique for detecting protein-protein interactions that utilizes the well-developed molecular genetics of the yeast Saccharomyces cerevisiae. However, the full potential of this technique has not been realized due to limitations imposed by the components available for use in the system. These limitations include unwieldy plasmid vectors, incomplete or poorly designed two-hybrid libraries, and host strains that result in the selection of large numbers of false positives. We have used a novel multienzyme approach to generate a set of highly representative genomic libraries from S. cerevisiae. In addition, a unique host strain was created that contains three easily assayed reporter genes, each under the control of a different inducible promoter. This host strain is extremely sensitive to weak interactions and eliminates nearly all false positives using simple plate assays. Improved vectors were also constructed that simplify the construction of the gene fusions necessary for the two-hybrid system. Our analysis indicates that the libraries and host strain provide significant improvements in both the number of interacting clones identified and the efficiency of two-hybrid selections. PMID:8978031

  12. Geosmin, an Earthy-Smelling Substance Isolated from Actinomycetes

    PubMed Central

    Gerber, N. N.; Lechevalier, H. A.

    1965-01-01

    Geosmin, an earthy-smelling substance, has been isolated from several actinomycetes. Production of 1 mg per liter of whole broth was obtained from Streptomyces griseus LP-16. After preliminary separations, pure geosmin was isolated in milligram amounts by gas chromatography. Geosmin is a neutral oil, with an approximate boiling point of 270 C, which contains carbon and hydrogen, but no nitrogen. It undergoes a reaction with acid to give odorless argosmin, a neutral oil, with an approximate boiling point of 230 C, which contains only carbon and hydrogen. Specific rotation and ultraviolet- and infrared-absorbtion spectra were determined for both. PMID:5866039

  13. Design and Validation of Equiaxial Mechanical Strain Platform, EQUicycler, for 3D Tissue Engineered Constructs.

    PubMed

    Elsaadany, Mostafa; Harris, Matthew; Yildirim-Ayan, Eda

    2017-01-01

    It is crucial to replicate the micromechanical milieu of native tissues to achieve efficacious tissue engineering and regenerative therapy. In this study, we introduced an innovative loading platform, EQUicycler, that utilizes a simple, yet effective, and well-controlled mechanism to apply physiologically relevant homogenous mechanical equiaxial strain on three-dimensional cell-embedded tissue scaffolds. The design of EQUicycler ensured elimination of gripping effects through the use of biologically compatible silicone posts for direct transfer of the mechanical load to the scaffolds. Finite Element Modeling (FEM) was created to understand and to quantify how much applied global strain was transferred from the loading mechanism to the tissue constructs. In vitro studies were conducted on various cell lines associated with tissues exposed to equiaxial mechanical loading in their native environment. In vitro results demonstrated that EQUicycler was effective in maintaining and promoting the viability of different musculoskeletal cell lines and upregulating early differentiation of osteoprogenitor cells. By utilizing EQUicycler, collagen fibers of the constructs were actively remodeled. Residing cells within the collagen construct elongated and aligned with strain direction upon mechanical loading. EQUicycler can provide an efficient and cost-effective tool to conduct mechanistic studies for tissue engineered constructs designed for tissue systems under mechanical loading in vivo.

  14. Design and Validation of Equiaxial Mechanical Strain Platform, EQUicycler, for 3D Tissue Engineered Constructs

    PubMed Central

    Harris, Matthew

    2017-01-01

    It is crucial to replicate the micromechanical milieu of native tissues to achieve efficacious tissue engineering and regenerative therapy. In this study, we introduced an innovative loading platform, EQUicycler, that utilizes a simple, yet effective, and well-controlled mechanism to apply physiologically relevant homogenous mechanical equiaxial strain on three-dimensional cell-embedded tissue scaffolds. The design of EQUicycler ensured elimination of gripping effects through the use of biologically compatible silicone posts for direct transfer of the mechanical load to the scaffolds. Finite Element Modeling (FEM) was created to understand and to quantify how much applied global strain was transferred from the loading mechanism to the tissue constructs. In vitro studies were conducted on various cell lines associated with tissues exposed to equiaxial mechanical loading in their native environment. In vitro results demonstrated that EQUicycler was effective in maintaining and promoting the viability of different musculoskeletal cell lines and upregulating early differentiation of osteoprogenitor cells. By utilizing EQUicycler, collagen fibers of the constructs were actively remodeled. Residing cells within the collagen construct elongated and aligned with strain direction upon mechanical loading. EQUicycler can provide an efficient and cost-effective tool to conduct mechanistic studies for tissue engineered constructs designed for tissue systems under mechanical loading in vivo. PMID:28168197

  15. Isolation and evaluation of proteolytic actinomycete isolates as novel inducers of pearl millet downy mildew disease protection

    PubMed Central

    Jogaiah, Sudisha; Kurjogi, Mahantesh; Govind, Sharathchandra Ramasandra; Huntrike, Shekar Shetty; Basappa, Vedamurthy Ankala; Tran, Lam-Son Phan

    2016-01-01

    Native endophytic actinomycetes isolated from pearl millet roots were examined for their efficacy to protect pearl millet against downy mildew. Nineteen of 39 isolates were found to be proteolytic, of which 7 strains could directly suppress the sporangium formation of Sclerospora graminicola, the pearl millet downy mildew pathogen. Thus, mycelial suspensions containing either spores or cell-free extract of these 7 isolates were used for seed-coating and -soaking treatments to test for their induction of downy mildew resistance. Results indicated that seed-coating overall provided better protection to downy mildew than seed-soaking. In both treatments, the tested isolates demonstrated differential abilities in downy mildew disease protection, with Streptomyces griseus SJ_UOM-07-09 and Streptosporangium roseum SJ_UOM-18-09 showing the highest protection rates. Additionally, the levels of disease protection conferred by the actinomycetes were just slightly lower than that of the systemic fungicide Apron, suggesting their effectiveness. Further studies revealed that the more rapid root colonization by SJ_UOM-18-09 resulted in faster and higher induced resistance in comparison with SJ_UOM-07-09 under greenhouse conditions, indicating that SJ_UOM-18-09 was superior than SJ_UOM-07-09 in inducing resistance. Results from this study provide comprehensive information on biocontrol functions of SJ_UOM- 18-09 with great potential to control downy mildew disease in pearl millet. PMID:27499196

  16. Design of atomic step networks on Si(111) through strain distribution control

    NASA Astrophysics Data System (ADS)

    Omi, Hiroo; Homma, Yoshikazu; Ogino, Toshio; Stoyanov, Stoyan; Tonchev, Vesselin

    2004-01-01

    We propose an alternative method to control atomic step networks on silicon for future wafer-scale integration of self-assembling nanostructures. The method is the strain-distribution-control method that we have recently proposed in [H. Omi, D. J. Bottomley, and T. Ogino, Appl. Phys. Lett. 80, 1073 (2002)], which we apply here to design atomic step networks on vicinal Si(111) wafer. Si(111) with its strain patterned by buried silicon oxide inclusions was annealed at 1230 °C in ultrahigh vacuum and observed by in situ secondary electron microscopy and ex situ atomic force microscopy. The images show that the method enables us to create the desired arrays of atomic step networks on an arbitrary area of planar silicon wafer. The arrays remain stable during the 1230 °C annealing.

  17. How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Yi, S.; Ghaffarian, R.

    2017-01-01

    It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

  18. How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Yi, S.; Ghaffarian, R.

    2017-03-01

    It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

  19. Discovery of phosphonic acid natural products by mining the genomes of 10,000 actinomycetes.

    PubMed

    Ju, Kou-San; Gao, Jiangtao; Doroghazi, James R; Wang, Kwo-Kwang A; Thibodeaux, Christopher J; Li, Steven; Metzger, Emily; Fudala, John; Su, Joleen; Zhang, Jun Kai; Lee, Jaeheon; Cioni, Joel P; Evans, Bradley S; Hirota, Ryuichi; Labeda, David P; van der Donk, Wilfred A; Metcalf, William W

    2015-09-29

    Although natural products have been a particularly rich source of human medicines, activity-based screening results in a very high rate of rediscovery of known molecules. Based on the large number of natural product biosynthetic genes in microbial genomes, many have proposed "genome mining" as an alternative approach for discovery efforts; however, this idea has yet to be performed experimentally on a large scale. Here, we demonstrate the feasibility of large-scale, high-throughput genome mining by screening a collection of over 10,000 actinomycetes for the genetic potential to make phosphonic acids, a class of natural products with diverse and useful bioactivities. Genome sequencing identified a diverse collection of phosphonate biosynthetic gene clusters within 278 strains. These clusters were classified into 64 distinct groups, of which 55 are likely to direct the synthesis of unknown compounds. Characterization of strains within five of these groups resulted in the discovery of a new archetypical pathway for phosphonate biosynthesis, the first (to our knowledge) dedicated pathway for H-phosphinates, and 11 previously undescribed phosphonic acid natural products. Among these compounds are argolaphos, a broad-spectrum antibacterial phosphonopeptide composed of aminomethylphosphonate in peptide linkage to a rare amino acid N(5)-hydroxyarginine; valinophos, an N-acetyl l-Val ester of 2,3-dihydroxypropylphosphonate; and phosphonocystoximate, an unusual thiohydroximate-containing molecule representing a new chemotype of sulfur-containing phosphonate natural products. Analysis of the genome sequences from the remaining strains suggests that the majority of the phosphonate biosynthetic repertoire of Actinobacteria has been captured at the gene level. This dereplicated strain collection now provides a reservoir of numerous, as yet undiscovered, phosphonate natural products.

  20. Identification of actinomycete communities in Antarctic soil from Barrientos Island using PCR-denaturing gradient gel electrophoresis.

    PubMed

    Learn-Han, L; Yoke-Kqueen, C; Shiran, M S; Vui-Ling, C M W; Nurul-Syakima, A M; Son, R; Andrade, H M

    2012-02-08

    The diversity of specific bacteria taxa, such as the actinomycetes, has not been reported from the Antarctic island of Barrientos. The diversity of actinomycetes was estimated with two different strategies that use PCR-denaturing gradient gel electrophoresis. First, a PCR was applied, using a group-specific primer that allows selective amplification of actinomycete sequences. Second, a nested-PCR approach was used that allows the estimation of the relative abundance of actinomycetes within the bacterial community. Molecular identification, which was based on 16S rDNA sequence analysis, revealed eight genera of actinomycetes, Actinobacterium, Actinomyces, an uncultured Actinomycete, Streptomyces, Leifsonia, Frankineae, Rhodococcus, and Mycobacterium. The uncultured Actinomyces sp and Rhodococcus sp appear to be the prominent genera of actinomycetes in Barrientos Island soil. PCR-denaturing gradient gel electrophoresis patterns were used to look for correlations between actinomycete abundance and environmental characteristics, such as type of rookery and vegetation. There was a significant positive correlation between type of rookery and abundance of actinomycetes; soil samples collected from active chinstrap penguin rookeries had the highest actinomycete abundance. Vegetation type, such as moss, which could provide a microhabitat for bacteria, did not correlate significantly with actinomycete abundance.

  1. Studies on carboxymethyl cellulase produced by an alkalothermophilic actinomycete.

    PubMed

    George, S P; Ahmad, A; Rao, M B

    2001-04-01

    A novel alkalothermophilic actinomycete having optimum growth at pH 9 and 50 degrees C was isolated from self-heating compost from the Barabanki district of Uttar Pradesh, India. Based on its morphology, susceptibility of spores to heat and novobiocin, guaninecytosine content of chromosomal DNA and cell wall composition, the organism was classified under Thermomonospora. The alkalothermophilic actinomycete produced 23 IU/ml carboxymethyl cellulase (CMCase). The CMCase was purified by fractional ammonium sulphate precipitation followed by cellulose affinity chromatography and Sephacryl S-200 gel filtration. The CMCase had a molecular weight of 38 KD and pI of 4.1. The enzyme exhibited optimum activity at pH 5 and temperature 50 degrees C. The CMCase showed pH stability in the range 7-10. The enzyme retained 100% activity at 50 degrees C for 72 h and had half-lives of 7 and 3 h at 60 degrees C and 70 degrees C, respectively. The CMCase was stable in the presence of commercial detergents such as Ariel, Henko and Surf Excel, indicating its potential as an additive to laundry detergents.

  2. Molecular insights on the biosynthesis of antitumour compounds by actinomycetes.

    PubMed

    Olano, Carlos; Méndez, Carmen; Salas, José A

    2011-03-01

    Natural products are traditionally the main source of drug leads. In particular, many antitumour compounds are either natural products or derived from them. However, the search for novel antitumour drugs active against untreatable tumours, with fewer side-effects or with enhanced therapeutic efficiency, is a priority goal in cancer chemotherapy. Microorganisms, particularly actinomycetes, are prolific producers of bioactive compounds, including antitumour drugs, produced as secondary metabolites. Structural genes involved in the biosynthesis of such compounds are normally clustered together with resistance and regulatory genes, which facilitates the isolation of the gene cluster. The characterization of these clusters has represented, during the last 25 years, a great source of genes for the generation of novel derivatives by using combinatorial biosynthesis approaches: gene inactivation, gene expression, heterologous expression of the clusters or mutasynthesis. In addition, these techniques have been also applied to improve the production yields of natural and novel antitumour compounds. In this review we focus on some representative antitumour compounds produced by actinomycetes covering the genetic approaches used to isolate and validate their biosynthesis gene clusters, which finally led to generating novel derivatives and to improving the production yields.

  3. Molecular insights on the biosynthesis of antitumour compounds by actinomycetes

    PubMed Central

    Olano, Carlos; Méndez, Carmen; Salas, José A.

    2011-01-01

    Summary Natural products are traditionally the main source of drug leads. In particular, many antitumour compounds are either natural products or derived from them. However, the search for novel antitumour drugs active against untreatable tumours, with fewer side‐effects or with enhanced therapeutic efficiency, is a priority goal in cancer chemotherapy. Microorganisms, particularly actinomycetes, are prolific producers of bioactive compounds, including antitumour drugs, produced as secondary metabolites. Structural genes involved in the biosynthesis of such compounds are normally clustered together with resistance and regulatory genes, which facilitates the isolation of the gene cluster. The characterization of these clusters has represented, during the last 25 years, a great source of genes for the generation of novel derivatives by using combinatorial biosynthesis approaches: gene inactivation, gene expression, heterologous expression of the clusters or mutasynthesis. In addition, these techniques have been also applied to improve the production yields of natural and novel antitumour compounds. In this review we focus on some representative antitumour compounds produced by actinomycetes covering the genetic approaches used to isolate and validate their biosynthesis gene clusters, which finally led to generating novel derivatives and to improving the production yields. PMID:21342461

  4. Biosynthesis and pathway engineering of antifungal polyene macrolides in actinomycetes.

    PubMed

    Kong, Dekun; Lee, Mi-Jin; Lin, Shuangjun; Kim, Eung-Soo

    2013-06-01

    Polyene macrolides are a large family of natural products typically produced by soil actinomycetes. Polyene macrolides are usually biosynthesized by modular and large type I polyketide synthases (PKSs), followed by several steps of sequential post-PKS modifications such as region-specific oxidations and glycosylations. Although known as powerful antibiotics containing potent antifungal activities (along with additional activities against parasites, enveloped viruses and prion diseases), their high toxicity toward mammalian cells and poor distribution in tissues have led to the continuous identification and structural modification of polyene macrolides to expand their general uses. Advances in in-depth investigations of the biosynthetic mechanism of polyene macrolides and the genetic manipulations of the polyene biosynthetic pathways provide great opportunities to generate new analogues. Recently, a novel class of polyene antibiotics was discovered (a disaccharide-containing NPP) that displays better pharmacological properties such as improved water-solubility and reduced hemolysis. In this review, we summarize the recent advances in the biosynthesis, pathway engineering, and regulation of polyene antibiotics in actinomycetes.

  5. New Dimensions of Research on Actinomycetes: Quest for Next Generation Antibiotics

    PubMed Central

    Jose, Polpass Arul; Jha, Bhavanath

    2016-01-01

    Starting with the discovery of streptomycin, the promise of natural products research on actinomycetes has been captivating researchers and offered an array of life-saving antibiotics. However, most of the actinomycetes have received a little attention of researchers beyond isolation and activity screening. Noticeable gaps in genomic information and associated biosynthetic potential of actinomycetes are mainly the reasons for this situation, which has led to a decline in the discovery rate of novel antibiotics. Recent insights gained from genome mining have revealed a massive existence of previously unrecognized biosynthetic potential in actinomycetes. Successive developments in next-generation sequencing, genome editing, analytical separation and high-resolution spectroscopic methods have reinvigorated interest on such actinomycetes and opened new avenues for the discovery of natural and natural-inspired antibiotics. This article describes the new dimensions that have driven the ongoing resurgence of research on actinomycetes with historical background since the commencement in 1940, for the attention of worldwide researchers. Coupled with increasing advancement in molecular and analytical tools and techniques, the discovery of next-generation antibiotics could be possible by revisiting the untapped potential of actinomycetes from different natural sources. PMID:27594853

  6. Isolation and identification of actinomycetes for production of novel extracellular glutaminase free L-asparaginase.

    PubMed

    Saxena, Akansha; Upadhyay, Ramraj; Kango, Naveen

    2015-12-01

    Over the recent years glutaminase free L-asparaginase has gained more importance due to better therapeutic properties for treatment of acute lymphoblastic leukemia. Actinomycetes are known for L-asparaginase activity. In the current study, 80 actinomycetes were isolated from various soil habitats by serial dilution technique. Presence of L-asparaginase was investigated in a total of 240 actinomycetes by tubed agar method using modified M-9 medium. A total of 165 actinomycetes were found positive for L-asparaginase activity. Among these, 57 actinomycetes producing larger zones of L-asparagine hydrolysis were further screened for their capacity to produce glutaminase-free L-asparaginase. Four L-glutaminase-free actinomycetes were found to be potential L-asparaginase producers. These actinomycetes were identified as Streptomyces cyaneus (SAP 1287, CFS 1560), S. exfoliates (CFS 1557) and S. phaeochromogenes (GS 1573) on the basis of morphological and biochemical identification studies. Maximum L-asparaginase activity (19.2 Uml(-1)) was observed in culture filtrate of S. phaeochromogenes under submerged fermentation. Results indicate that S. phaeochromogenes could be a potential source of glutaminase free L-asparaginase for commercial purpose. To the best of our knowledge, this is the first report on production of glutaminase free L-asparaginase from S. cyaneus, S. exfoliatus and S. phaeochromogenes.

  7. Design of homo-organic acid producing strains using multi-objective optimization.

    PubMed

    Kim, Tae Yong; Park, Jong Myoung; Kim, Hyun Uk; Cho, Kwang Myung; Lee, Sang Yup

    2015-03-01

    Production of homo-organic acids without byproducts is an important challenge in bioprocess engineering to minimize operation cost for separation processes. In this study, we used multi-objective optimization to design Escherichia coli strains with the goals of maximally producing target organic acids, while maintaining sufficiently high growth rate and minimizing the secretion of undesired byproducts. Homo-productions of acetic, lactic and succinic acids were targeted as examples. Engineered E. coli strains capable of producing homo-acetic and homo-lactic acids could be developed by taking this systems approach for the minimal identification of gene knockout targets. Also, failure to predict effective gene knockout targets for the homo-succinic acid production suggests that the multi-objective optimization is useful in assessing the suitability of a microorganism as a host strain for the production of a homo-organic acid. The systems metabolic engineering-based approach reported here should be applicable to the production of other industrially important organic acids.

  8. Draft genome sequences of three chemically rich actinomycetes isolated from Mediterranean sponges.

    PubMed

    Horn, Hannes; Cheng, Cheng; Edrada-Ebel, RuAngelie; Hentschel, Ute; Abdelmohsen, Usama Ramadan

    2015-12-01

    Metabolomic analysis has shown the chemical richness of the sponge-associated actinomycetes Streptomyces sp. SBT349, Nonomureae sp. SBT364, and Nocardiopsis sp. SBT366. The genomes of these actinomycetes were sequenced and the genomic potential for secondary metabolism was evaluated. Their draft genomes have sizes of 8.0, 10, and 5.8 Mb having 687, 367, and 179 contigs with a GC content of 71.6, 70.7, and 72.7%, respectively. Moreover, antiSMASH 3.0 predicted 108, 149, and 75 secondary metabolite gene clusters, respectively which highlight the metabolic capacity of the three actinomycete species to produce diverse classes of natural products.

  9. A strain-absorbing design for tissue-machine interfaces using a tunable adhesive gel.

    PubMed

    Lee, Sungwon; Inoue, Yusuke; Kim, Dongmin; Reuveny, Amir; Kuribara, Kazunori; Yokota, Tomoyuki; Reeder, Jonathan; Sekino, Masaki; Sekitani, Tsuyoshi; Abe, Yusuke; Someya, Takao

    2014-12-19

    To measure electrophysiological signals from the human body, it is essential to establish stable, gentle and nonallergic contacts between the targeted biological tissue and the electrical probes. However, it is difficult to form a stable interface between the two for long periods, especially when the surface of the biological tissue is wet and/or the tissue exhibits motion. Here we resolve this difficulty by designing and fabricating smart, stress-absorbing electronic devices that can adhere to wet and complex tissue surfaces and allow for reliable, long-term measurements of vital signals. We demonstrate a multielectrode array, which can be attached to the surface of a rat heart, resulting in good conformal contact for more than 3 h. Furthermore, we demonstrate arrays of highly sensitive, stretchable strain sensors using a similar design. Ultra-flexible electronics with enhanced adhesion to tissue could enable future applications in chronic in vivo monitoring of biological signals.

  10. A strain-absorbing design for tissue-machine interfaces using a tunable adhesive gel

    NASA Astrophysics Data System (ADS)

    Lee, Sungwon; Inoue, Yusuke; Kim, Dongmin; Reuveny, Amir; Kuribara, Kazunori; Yokota, Tomoyuki; Reeder, Jonathan; Sekino, Masaki; Sekitani, Tsuyoshi; Abe, Yusuke; Someya, Takao

    2014-12-01

    To measure electrophysiological signals from the human body, it is essential to establish stable, gentle and nonallergic contacts between the targeted biological tissue and the electrical probes. However, it is difficult to form a stable interface between the two for long periods, especially when the surface of the biological tissue is wet and/or the tissue exhibits motion. Here we resolve this difficulty by designing and fabricating smart, stress-absorbing electronic devices that can adhere to wet and complex tissue surfaces and allow for reliable, long-term measurements of vital signals. We demonstrate a multielectrode array, which can be attached to the surface of a rat heart, resulting in good conformal contact for more than 3 h. Furthermore, we demonstrate arrays of highly sensitive, stretchable strain sensors using a similar design. Ultra-flexible electronics with enhanced adhesion to tissue could enable future applications in chronic in vivo monitoring of biological signals.

  11. Pathobiology of aging mice and GEM: background strains and experimental design.

    PubMed

    Brayton, C F; Treuting, P M; Ward, J M

    2012-01-01

    The use of induced and spontaneous mutant mice and genetically engineered mice (and combinations thereof) to study cancers and other aging phenotypes to advance improved functional human life spans will involve studies of aging mice. Genetic background contributes to pathology phenotypes and to causes of death as well as to longevity. Increased recognition of expected phenotypes, experimental variables that influence phenotypes and research outcomes, and experimental design options and rationales can maximize the utility of genetically engineered mice (GEM) models to translational research on aging. This review aims to provide resources to enhance the design and practice of chronic and longevity studies involving GEM. C57BL6, 129, and FVB/N strains are emphasized because of their widespread use in the generation of knockout, transgenic, and conditional mutant GEM. Resources are included also for pathology of other inbred strain families, including A, AKR, BALB/c, C3H, C57L, C58, CBA, DBA, GR, NOD.scid, SAMP, and SJL/J, and non-inbred mice, including 4WC, AB6F1, Ames dwarf, B6, 129, B6C3F1, BALB/c,129, Het3, nude, SENCAR, and several Swiss stocks. Experimental strategies for long-term cross-sectional and longitudinal studies to assess causes of or contributors to death, disease burden, spectrum of pathology phenotypes, longevity, and functional healthy life spans (health spans) are compared and discussed.

  12. Design of Stress-Strain Measuring System for Bulldozing Plate Based on Virtual Instrument Technology

    NASA Astrophysics Data System (ADS)

    Xu, S. C.; Li, J. Q.; Zhang, R.

    2006-10-01

    Soil is a kind of discrete, multiphase compound that is composed of soil particles, liquid and air. When soil is disturbed by bulldozing plate, the mechanical behavior of the soil will become very complex. Based on the law of action and reaction, the dynamic mechanical behavior of disturbed soil was indirectly analyzed by measuring and studying the forces on the bulldozing plate by soil currently, so a stress-strain virtual measuring system for bulldozing plate, which was designed by the graphical programming language DASYLab, was used to measure the horizontal force Fz acting on the bulldozing plate. In addition, during the course of design, the experimental complexities and the interferential factors influencing on signal logging were analyzed when bulldozing plate worked, so the anti-jamming methods of hardware and software technology were adopted correlatively. In the end, the horizontal force Fz was analyzed with Error Theory, the result shown that the quantificational analysis of Fz were identical to the qualitative results of soil well, and the error of the whole test system is under 5 percent, so the tress-strain virtual measuring system was stable and credible.

  13. Production and characterization of lipopeptide biosurfactant by a sponge-associated marine actinomycetes Nocardiopsis alba MSA10.

    PubMed

    Gandhimathi, R; Seghal Kiran, G; Hema, T A; Selvin, Joseph; Rajeetha Raviji, T; Shanmughapriya, S

    2009-10-01

    A sponge-associated marine actinomycetes Nocardiopsis alba MSA10 was screened and evaluated for the production of biosurfactant. Biosurfactant production was confirmed by conventional screening methods including hemolytic activity, drop collapsing test, oil displacement method, lipase production and emulsification index. The active compound was extracted with three solvents including ethyl acetate, diethyl ether and dichloromethane. The diethyl ether extract was fractionated by TLC and semi-preparative HPLC to isolate the pure compound. In TLC, a single discrete spot was obtained with the R (f) 0.60 and it was extrapolated as valine. Based on the chemical characterization, the active compound was partially confirmed as lipopeptide. The optimum production was attained at pH 7, temperature 30 degrees C, and 1% salinity with glucose and peptone supplementation as carbon and nitrogen sources, respectively. Considering the biosurfactant production potential of N. alba, the strain could be developed for large-scale production of lipopeptide biosurfactant.

  14. Generic and functional diversity in endophytic actinomycetes from wild Compositae plant species at South Sinai - Egypt.

    PubMed

    El-Shatoury, Sahar A; El-Kraly, Omnia A; Trujillo, Martha E; El-Kazzaz, Waleed M; El-Din, El-Sayeda Gamal; Dewedar, Ahmed

    2013-09-01

    The diversity of culturable endophytic actinomycetes associated with wild Compositae plants is scantily explored. In this study, one hundred and thirty one endophytic actinobacteria were isolated from ten Compositae plant species collected from South Sinai in Egypt. Microscopic and chemotaxonomic investigation of the isolates indicated fourteen genera. Rare genera, such as Microtetraspora, and Intrasporangium, which have never been previously reported to be endophytic, were identified. Each plant species accommodated between three to eight genera of actinobacteria and unidentified strains were recovered from seven plant species. The generic diversity analysis of endophytic assemblages grouped the plant species into three main clusters, representing high, moderate and low endophytic diversity. The endophytes showed high functional diversity, based on forty four catabolic and plant growth promotion traits; providing some evidence that such traits could represent key criteria for successful residence of endophytes in the endosphere. Stress-tolerance traits were more predictive measure of functional diversity differences between the endophyte assemblages (Shannon's index, p = 0.01). The results indicate a potential prominent role of endophytes for their hosts and emphasize the potency of plant endosphere as a habitat for actinobacteria with promising future applications.

  15. Streptomyces atlanticus sp. nov., a novel actinomycete isolated from marine sponge Aplysina fulva (Pallas, 1766).

    PubMed

    Silva, Fábio Sérgio Paulino; Souza, Danilo Tosta; Zucchi, Tiago Domingues; Pansa, Camila Cristiane; de Figueiredo Vasconcellos, Rafael Leandro; Crevelin, Eduardo José; de Moraes, Luiz Alberto Beraldo; Melo, Itamar Soares

    2016-11-01

    The taxonomic position of a novel marine actinomycete isolated from a marine sponge, Aplysina fulva, which had been collected in the Archipelago of Saint Peter and Saint Paul (Equatorial Atlantic Ocean), was determined by using a polyphasic approach. The organism showed a combination of morphological and chemotaxonomic characteristics consistent with its classification in the genus Streptomyces and forms a distinct branch within the Streptomyces somaliensis 16S rRNA gene tree subclade. It is closely related to Streptomyces violascens ISP 5183(T) (97.27 % 16S rRNA gene sequence similarity) and Streptomyces hydrogenans NBRC 13475(T) (97.15 % 16S rRNA gene sequence similarity). The 16S rRNA gene similarities between the isolate and the remaining members of the subclade are lower than 96.77 %. The organism can be distinguished readily from other members of the S. violacens subclade using a combination of phenotypic properties. On the basis of these results, it is proposed that isolate 103(T) (=NRRL B-65309(T) = CMAA 1378(T)) merits recognition as the type strain of a new Streptomyces species, namely Streptomyces atlanticus sp. nov.

  16. Biotechnological potential of endophytic actinomycetes associated with Asteraceae plants: isolation, biodiversity and bioactivities.

    PubMed

    Tanvir, Rabia; Sajid, Imran; Hasnain, Shahida

    2014-04-01

    Endophytic actinomycetes from five Asteraceae plants were isolated and evaluated for their bioactivities. From Parthenium hysterophorus, Ageratum conyzoides, Sonchus oleraceus, Sonchus asper and Hieracium canadense, 42, 45, 90, 3, and 2 isolates, respectively, were obtained. Of the isolates, 86 (47.2 %) showed antimicrobial activity. Majority of the isolates were recovered from the roots (n = 127, 69.7 %). The dominant genus was Streptomyces (n = 96, 52.7 %), while Amycolatopsis, Pseudonocardia, Nocardia and Micromonospora were also recovered. Overall, 36 of the 86 isolates were significantly bioactivity while 18 (20.9 %) showed strong bioactivity. In total, 52.1 and 66.6 % showed potent cytotoxicity and antioxidant activities. The LC50 for 15 strains was <20 μg/ml. Compared to the ascorbate standard (EC50 0.34 μg/ml), all isolates gave impressive results with notable EC50 values of 0.65, 0.67, 0.74 and 0.79 μg/ml.

  17. Marine actinomycetes as an emerging resource for the drug development pipelines.

    PubMed

    Zotchev, Sergey B

    2012-04-30

    Many representatives of the order Actinomycetales are prolific producers of thousands of biologically active secondary metabolites. Actinomycetes from terrestrial sources have been studied and screened since the 1950s, yielding many important anti-infective and anti-cancer drugs. However, frequent re-discovery of the same compounds in terrestrial actinomycetes have made them less attractive for screening programs in the recent years. At the same time, actinomycetes isolated from the marine environment currently receive considerable attention due to the structural diversity and unique biological activities of their secondary metabolites. This review highlights achievements and challenges in the isolation of marine actinomycetes, some examples of bioactive metabolites identified by conventional screening, and presents new developments in the field of genome mining and heterologous expression of biosynthetic gene clusters leading to the discovery of novel compounds.

  18. Specificity of actinomycetal complexes in urbanozems of the city of Kirov

    NASA Astrophysics Data System (ADS)

    Shirokikh, I. G.; Ashikhmina, T. Ya.; Shirokikh, A. A.

    2011-02-01

    The number and composition of the actinomycetal population was studied in urbanozems in the city of Kirov. It was shown that the total population of actinomycetes was an order of magnitude lower than that in the background territories, and the generic structure of the actinomycetal complex and the species composition of the streptomycetes were transformed under the influence of the urbanization factors. The obtained data were compared with the concentrations of the mobile forms of Pb, Zn, Cu, Fe, and Mn in different ecotopes (industrial, traffic, and recreation zones). The increase of the relative portion of micromonosporic actinomycetes in comparison with the background (reference) soils was observed in the complexes of the industrial and transport ecotopes mostly contaminated with heavy metals. It was found that the antibiotic potential of the streptomycetes in the contaminated soils was lower than in the soils of the background territories.

  19. Diversity of actinomycetes isolated from subseafloor sediments after prolonged low-temperature storage.

    PubMed

    Ulanova, Dana; Goo, Kian-Sim

    2015-05-01

    Subseafloor sediments present an untapped source of novel bacterial species with industrially important bioactivities. Subseafloor core samples collected during the Integrated Ocean Drilling Program Expeditions 315, 316, and 331 and stored in Kochi Core Center at -80 °C for 1 to 4 years were used for cultivation-based study of viable actinomycetes. In total, more than 100 actinomycete-like colonies were isolated from two deep-frozen subseafloor sediment samples. Isolated actinomycetes showed close similarity to known Actinotalea, Dietzia, Gordonia, Isoptericola, Microbacterium, Nocardia, Rhodococcus, Pseudonocardia, Streptomyces, and Tsukamurella species and were halotolerant. Bioactivity assays revealed that two of the isolates were producing potent antibacterial compound(s) and one isolate was having antifungal activity. Our study demonstrated that deep-frozen subseafloor core samples could be a potential source of viable actinomycetes, which may be used in drug discovery.

  20. Psychrotolerant actinomycetes of plants and organic horizons in tundra and taiga soils

    NASA Astrophysics Data System (ADS)

    Dubrova, M. S.; Zenova, G. M.; Yakushev, A. V.; Manucharova, N. A.; Makarova, E. P.; Zvyagintsev, D. G.; Chernov, I. Yu.

    2013-08-01

    It has been revealed that in organic horizons and plants of the tundra and taiga ecosystems under low temperatures, actinomycetal complexes form. The population density of psychrotolerant actinomycetes in organic horizons and plants reaches tens and hundreds of thousands CFU/g of substrate or soil, and decreases in the sequence litters > plants > soils > undecomposed plant remains > moss growths. The mycelium length of psychrotolerant actinomycetes reaches 220 m/g of substrate. Application of the FISH method has demonstrated that metabolically active psychrotolerant bacteria of the phylum Actinobacteria constitute 30% of all metabolically active psychrotolerant representatives of the Bacterià domain of the prokaryotic microbial community of soils and plants. Psychrotolerant actinomycetes in tundra and taiga ecosystems possess antimicrobial properties.

  1. Psoas abscess caused by actinomycete together with Escherichia coli infection: a case report and literature review

    PubMed Central

    Chen, Qian; Ding, Wenyuan; Yang, Dalong

    2014-01-01

    Psoas abscesses are classified into primary or secondary according to infectious etiology. However, the psoas abscess caused by actinomycete together with Escherichia coli infection is very rare. Here we report a case of psoas abscess caused by actinomycete together with Escherichia coli infection in a young woman. The disease was treated successfully. A literature review of psoas abscess in relation to its etiology, identification, and difficulties in the treatment is also presented. PMID:25356161

  2. Exploring plant growth-promotion actinomycetes from vermicompost and rhizosphere soil for yield enhancement in chickpea.

    PubMed

    Sreevidya, M; Gopalakrishnan, S; Kudapa, H; Varshney, R K

    2016-01-01

    The main objective of the present study was to isolate and characterize actinomycetes for their plant growth-promotion in chickpea. A total of 89 actinomycetes were screened for their antagonism against fungal pathogens of chickpea by dual culture and metabolite production assays. Four most promising actinomycetes were evaluated for their physiological and plant growth-promotion properties under in vitro and in vivo conditions. All the isolates exhibited good growth at temperatures from 20°C to 40°C, pH range of 7-11 and NaCl concentrations up to 8%. These were also found highly tolerant to Bavistin, slightly tolerant to Thiram and Captan (except VAI-7 and VAI-40) but susceptible to Benlate and Ridomil at field application levels and were found to produce siderophore, cellulase, lipase, protease, chitinase (except VAI-40), hydrocyanic acid (except VAI-7 and VAI-40), indole acetic acid and β-1,3-glucanase. When the four actinomycetes were evaluated for their plant growth-promotion properties under field conditions on chickpea, all exhibited increase in nodule number, shoot weight and yield. The actinomycetes treated plots enhanced total N, available P and organic C over the un-inoculated control. The scanning electron microscope studies exhibited extensive colonization by actinomycetes on the root surface of chickpea. The expression profiles for indole acetic acid, siderophore and β-1,3-glucanase genes exhibited up-regulation for all three traits and in all four isolates. The actinomycetes were identified as Streptomyces but different species in the 16S rDNA analysis. It was concluded that the selected actinomycetes have good plant growth-promotion and biocontrol potentials on chickpea.

  3. Exploring plant growth-promotion actinomycetes from vermicompost and rhizosphere soil for yield enhancement in chickpea

    PubMed Central

    Sreevidya, M.; Gopalakrishnan, S.; Kudapa, H.; Varshney, R.K.

    2016-01-01

    The main objective of the present study was to isolate and characterize actinomycetes for their plant growth-promotion in chickpea. A total of 89 actinomycetes were screened for their antagonism against fungal pathogens of chickpea by dual culture and metabolite production assays. Four most promising actinomycetes were evaluated for their physiological and plant growth-promotion properties under in vitro and in vivo conditions. All the isolates exhibited good growth at temperatures from 20 °C to 40 °C, pH range of 7–11 and NaCl concentrations up to 8%. These were also found highly tolerant to Bavistin, slightly tolerant to Thiram and Captan (except VAI-7 and VAI-40) but susceptible to Benlate and Ridomil at field application levels and were found to produce siderophore, cellulase, lipase, protease, chitinase (except VAI-40), hydrocyanic acid (except VAI-7 and VAI-40), indole acetic acid and β-1,3-glucanase. When the four actinomycetes were evaluated for their plant growth-promotion properties under field conditions on chickpea, all exhibited increase in nodule number, shoot weight and yield. The actinomycetes treated plots enhanced total N, available P and organic C over the un-inoculated control. The scanning electron microscope studies exhibited extensive colonization by actinomycetes on the root surface of chickpea. The expression profiles for indole acetic acid, siderophore and β-1,3-glucanase genes exhibited up-regulation for all three traits and in all four isolates. The actinomycetes were identified as Streptomyces but different species in the 16S rDNA analysis. It was concluded that the selected actinomycetes have good plant growth-promotion and biocontrol potentials on chickpea. PMID:26887230

  4. Stimulation of 2-methylisoborneol (MIB) production by actinomycetes after cyclic chlorination in drinking water distribution systems.

    PubMed

    Abbaszadegan, Morteza; Yi, Min; Alum, Absar

    2015-01-01

    The impact of fluctuation in chlorine residual on actinomycetes and the production of 2-methylisoborneol (MIB) were studied in cast-iron and PVC model distribution systems. Actinomycetes were spiked in each system and continued operation for a 12-day non-chlorine experiment, resulting in no changes in actinomycetes and MIB concentrations. Three cyclic chlorination events were performed and chlorine residuals were maintained as follows: 1.0 mg L(-1) for 24 h, 0 mg L(-1) for 48 h, 0.5 mg L(-1) for 48 h, 0 mg L(-1) for 48 h and 2 mg L(-1) for 24 h. After each chlorination event, 2 -3 log decrease in actinomycetes was noted in both systems. However, within 48 h at 0 mg L(-1) chlorine, the actinomycetes recovered to the pre-chlorination levels. On the contrary, MIB concentration in both systems remained un-impacted after the first cycle and increased by fourfold (< 5 to > 20 mg L(-1)) after the second cycle, which lasted through the third cycle despite the fact that actinomycetes numbers fluctuated 2-3 logs during this time period. For obtaining biofilm samples from field, water meters were collected from municipality drinking water distribution systems located in central Arizona. The actinomycetes concentration in asbestos cement pipe and cast iron pipe averaged 3.1 × 10(3) and 1.9 × 10(4) CFU cm(-2), respectively. The study shows that production of MIB is associated with changes in chlorine residual in the systems. This is the first report of cyclic chlorine shock as a stimulus for MIB production by actinomycetes in drinking water distribution system's ecology.

  5. Design of a Probe for Strain Sensitivity Studies of Critical Current Densities in SC Wires and Tapes

    SciTech Connect

    Dhanaraj, N.; Barzi, E.; Turrioni, D.; Rusy, A.; Lombardo, V.; /Fermilab

    2011-07-01

    The design of a variable-temperature probe used to perform strain sensitivity measurements on LTS wires and HTS wires and tapes is described. The measurements are intended to be performed at liquid helium temperatures (4.2 K). The wire or tape to be measured is wound and soldered on to a helical spring device, which is fixed at one end and subjected to a torque at the free end. The design goal is to be able to achieve {+-} 0.8 % strain in the wire and tape. The probe is designed to carry a current of 2000A.

  6. Flux control-based design of furfural-resistance strains of Saccharomyces cerevisiae for lignocellulosic biorefinery.

    PubMed

    Unrean, Pornkamol

    2016-12-26

    We have previously developed a dynamic flux balance analysis of Saccharomyces cerevisiae for elucidation of genome-wide flux response to furfural perturbation (Unrean and Franzen, Biotechnol J 10(8):1248-1258, 2015). Herein, the dynamic flux distributions were analyzed by flux control analysis to identify target overexpressed genes for improved yeast robustness against furfural. The flux control coefficient (FCC) identified overexpressing isocitrate dehydrogenase (IDH1), a rate-controlling flux for ethanol fermentation, and dicarboxylate carrier (DIC1), a limiting flux for cell growth, as keys of furfural-resistance phenotype. Consistent with the model prediction, strain characterization showed 1.2- and 2.0-fold improvement in ethanol synthesis and furfural detoxification rates, respectively, by IDH1 overexpressed mutant compared to the control. DIC1 overexpressed mutant grew at 1.3-fold faster and reduced furfural at 1.4-fold faster than the control under the furfural challenge. This study hence demonstrated the FCC-based approach as an effective tool for guiding the design of robust yeast strains.

  7. Enhanced production of thermostable laccases from a native strain of Pycnoporus sanguineus using central composite design.

    PubMed

    Ramírez-Cavazos, Leticia I; Junghanns, Charles; Nair, Rakesh; Cárdenas-Chávez, Diana L; Hernández-Luna, Carlos; Agathos, Spiros N; Parra, Roberto

    2014-04-01

    The production of thermostable laccases from a native strain of the white-rot fungus Pycnoporus sanguineus isolated in Mexico was enhanced by testing different media and a combination of inducers including copper sulfate (CuSO4). The best conditions obtained from screening experiments in shaken flasks using tomato juice, CuSO4, and soybean oil were integrated in an experimental design. Enhanced levels of tomato juice as the medium, CuSO4 and soybean oil as inducers (36.8% (v/v), 3 mmol/L, and 1% (v/v), respectively) were determined for 10 L stirred tank bioreactor runs. This combination resulted in laccase titer of 143,000 IU/L (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), pH 3.0), which represents the highest activity so far reported for P. sanguineus in a 10-L fermentor. Other interesting media resulting from the screening included glucose-bactopeptone which increased laccase activity up to 20,000 IU/L, whereas the inducers Acid Blue 62 and Reactive Blue 19 enhanced enzyme production in this medium 10 times. Based on a partial characterization, the laccases of this strain are especially promising in terms of thermostability (half-life of 6.1 h at 60 °C) and activity titers.

  8. Enhanced production of thermostable laccases from a native strain of Pycnoporus sanguineus using central composite design*

    PubMed Central

    Ramírez-Cavazos, Leticia I.; Junghanns, Charles; Nair, Rakesh; Cárdenas-Chávez, Diana L.; Hernández-Luna, Carlos; Agathos, Spiros N.; Parra, Roberto

    2014-01-01

    The production of thermostable laccases from a native strain of the white-rot fungus Pycnoporus sanguineus isolated in Mexico was enhanced by testing different media and a combination of inducers including copper sulfate (CuSO4). The best conditions obtained from screening experiments in shaken flasks using tomato juice, CuSO4, and soybean oil were integrated in an experimental design. Enhanced levels of tomato juice as the medium, CuSO4 and soybean oil as inducers (36.8% (v/v), 3 mmol/L, and 1% (v/v), respectively) were determined for 10 L stirred tank bioreactor runs. This combination resulted in laccase titer of 143 000 IU/L (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), pH 3.0), which represents the highest activity so far reported for P. sanguineus in a 10-L fermentor. Other interesting media resulting from the screening included glucose-bactopeptone which increased laccase activity up to 20 000 IU/L, whereas the inducers Acid Blue 62 and Reactive Blue 19 enhanced enzyme production in this medium 10 times. Based on a partial characterization, the laccases of this strain are especially promising in terms of thermostability (half-life of 6.1 h at 60 °C) and activity titers. PMID:24711355

  9. Biodegradation of cis-1,4-Polyisoprene Rubbers by Distinct Actinomycetes: Microbial Strategies and Detailed Surface Analysis

    PubMed Central

    Linos, Alexandros; Berekaa, Mahmoud M.; Reichelt, Rudolf; Keller, Ulrike; Schmitt, Jürgen; Flemming, Hans-Curt; Kroppenstedt, Reiner M.; Steinbüchel, Alexander

    2000-01-01

    Several actinomycetes isolated from nature were able to use both natural rubber (NR) and synthetic cis-1,4-polyisoprene rubber (IR) as a sole source of carbon. According to their degradation behavior, they were divided into two groups. Representatives of the first group grew only in direct contact to the rubber substrate and led to considerable disintegration of the material during cultivation. The second group consisted of weaker rubber decomposers that did not grow adhesively, as indicated by the formation of clear zones (translucent halos) around bacterial colonies after cultivation on NR dispersed in mineral agar. Taxonomic analysis of four selected strains based on 16S rRNA similarity examinations revealed two Gordonia sp. strains, VH2 and Kb2, and one Mycobacterium fortuitum strain, NF4, belonging to the first group as well as one Micromonospora aurantiaca strain, W2b, belonging to the second group. Schiff's reagent staining tests performed for each of the strains indicated colonization of the rubber surface, formation of a bacterial biofilm, and occurrence of compounds containing aldehyde groups during cultivation with NR latex gloves. Detailed analysis by means of scanning electron microscopy yielded further evidence for the two different microbial strategies and clarified the colonization efficiency. Thereby, strains VH2, Kb2, and NF4 directly adhered to and merged into the rubber material, while strain W2b produced mycelial corridors, especially on the surface of IR. Fourier transform infrared spectroscopy comprising the attenuated total reflectance technique was applied on NR latex gloves overgrown by cells of the Gordonia strains, which were the strongest rubber decomposers. Spectra demonstrated the decrease in number of cis-1,4 double bonds, the formation of carbonyl groups, and the change of the overall chemical environment, indicating that an oxidative attack at the double bond is the first metabolic step of the biodegradation process. PMID:10742254

  10. Isolation and characterization of medically important aerobic actinomycetes in soil of iran (2006 - 2007).

    PubMed

    Aghamirian, Mohammad Reza; Ghiasian, Seyed Amir

    2009-01-01

    The aerobic actinomycetes are a large group of soil-inhabiting bacteria that occur worldwide. Some of them are the main cause of two important diseases, nocardiosis and actinomycetoma. To identify the prevalence and geographic distribution of aerobic actinomycetes in soil of Qazvin province, a study was carried out during 2006-2007. In this study, the incidence and diversity of medically important aerobic actinomycetes was determined in 300 soil samples of different parts of Qazvin. The suspensions of superficial soil samples were prepared by adding of normal saline, streptomycin and chloramphenicol and the supernatants were cultured on brain-heart infusion agar and Sabouraud's dextrose agar contain cycloheximide. The isolated microorganisms were examined by Gram and acid-fast stains and were identified biochemically and morphologically. Of 96 aerobic actinomycetes isolates identified, Actinomadura madurae and Streptomyces somaliensis were the most frequently isolated species each representing 19.8% of isolates, followed by Nocardia asteroides (15.6%), N. otitidiscaviarum (9.4%), N. brasiliensis (7.3%), A. peletieri, S. griseus, and Nocardia spp. (each 5.2%), and N. transvalensis, Nocardiopsis dassonvillei, Actinomadura spp. and Streptomyces spp. (each 3.1%). To the best of our knowledge, this is the first report on epidemiological investigation of medically important aerobic actinomycetes in soil samples from Iran. In recent years, mycetoma and nocardiosis have been increasingly reported in Iran. The results showed that medically important actinomycetes occur in the environment of Iran and soil could be potential source of actinomycotic infections.

  11. Bioactive Potential of Actinomycetes from Less Explored Ecosystems against Mycobacterium tuberculosis and Other Nonmycobacterial Pathogens

    PubMed Central

    Venugopal, Gopikrishnan; Subramaniam, Balaji; Ramasamy, Balagurunathan

    2014-01-01

    Bioactive potential of actinomycetes isolated from certain less explored Indian ecosystems against Mycobacterium tuberculosis and other nonmycobacterial pathogens was investigated. Actinomycetes were isolated from the soil samples collected from desert, coffee plantation, rubber forest, and hill area and their cultural and micromorphological characteristics were studied. Crude extracts were prepared by agar surface fermentation and tested against M. tuberculosis isolates by luciferase reporter phage (LRP) assay at 100 µg/mL. Activity against nonmycobacterial pathogens was studied by agar plug method. Totally 54 purified cultures of actinomycetes including 43 Streptomyces and 11 non-Streptomyces were isolated. While screening for antitubercular activity, extracts of 39 actinomycetes showed activity against one or more M. tuberculosis isolates whereas 27 isolates exhibited antagonistic activity against nonmycobacterial pathogens. In particular crude extracts from sixteen actinomycete isolates inhibited all the three M. tuberculosis isolates tested. Findings of the present study concluded that less explored ecosystems investigated in this study are the potential resource for bioactive actinomycetes. Further purification and characterization of active molecule from the potential extracts will pave the way for determination of MIC, toxicity, and specificity studies. PMID:27437460

  12. Continuing hunt for endophytic actinomycetes as a source of novel biologically active metabolites.

    PubMed

    Masand, Meeta; Jose, Polpass Arul; Menghani, Ekta; Jebakumar, Solomon Robinson David

    2015-12-01

    Drug-resistant pathogens and persistent agrochemicals mount the detrimental threats against human health and welfare. Exploitation of beneficial microorganisms and their metabolic inventions is most promising way to tackle these two problems. Since the successive discoveries of penicillin and streptomycin in 1940s, numerous biologically active metabolites have been discovered from different microorganisms, especially actinomycetes. In recent years, actinomycetes that inhabit unexplored environments have received significant attention due to their broad diversity and distinctive metabolic potential with medical, agricultural and industrial importance. In this scenario, endophytic actinomycetes that inhabit living tissues of plants are emerging as a potential source of novel bioactive compounds for the discovery of drug leads. Also, endophytic actinomycetes are considered as bio-inoculants to improve crop performance through organic farming practices. Further efforts on exploring the endophytic actinomycetes associated with the plants warrant the likelihood of discovering new taxa and their metabolites with novel chemical structures and biotechnological importance. This mini-review highlights the recent achievements in isolation of endophytic actinomycetes and an assortment of bioactive compounds.

  13. Actinomycetal complex of light sierozem on the Kopet-Dag piedmont plain

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Zvyagintsev, D. G.; Manucharova, N. A.; Stepanova, O. A.; Chernov, I. Yu.

    2016-10-01

    The population density of actinomycetes in the samples of light sierozem from the Kopet Dag piedmont plain (75 km from Ashkhabad, Turkmenistan) reaches hundreds of thousand CFU/g soil. The actinomycetal complex is represented by two genera: Streptomyces and Micromonospora. Representatives of the Streptomyces genus predominate and comprise 73 to 87% of the actinomycetal complex. In one sample, representatives of the Micromonospora genus predominated in the complex (75%). The Streptomyces genus in the studied soil samples is represented by the species from several sections and series: the species of section Helvolo-Flavus series Helvolus represent the dominant component of the streptomycetal complex; their portion is up to 77% of all isolated actinomycetes. The species of other sections and series are much less abundant. Thus, the percentage of the Cinereus Achromogenes section in the actinomycetal complex does not exceed 28%; representatives of the Albus section Albus series, Roseus section Lavendulae-Roseus series, and Imperfectus section belong to rare species; they have been isolated not from all the studied samples of light sierozem, and their portion does not exceed 10% of the actinomycetal complex.

  14. Improved vertical optical fiber borehole strainmeter design for measuring Earth strain.

    PubMed

    DeWolf, Scott; Wyatt, Frank K; Zumberge, Mark A; Hatfield, William

    2015-11-01

    Fiber-based interferometers provide the means to sense very small displacements over long baselines, and have the advantage of being nearly completely passive in their operation, making them particularly well suited for geophysical applications. A new 250 m, interferometric vertical borehole strainmeter has been developed based completely on passive optical components. Details of the design and deployment at the Piñon Flat Observatory are presented. Power spectra show an intertidal noise level of -130 dB (re. 1 ϵ(2)/Hz), consistent within 1-3 dB between redundant components. Examination of its response to Earth tides and earthquakes relative to the areal strain recorded by an orthogonal pair of collocated, 730 m horizontal laser strainmeters yield a Poisson's ratio for local near surface material of 0.25 that is consistent with previous results.

  15. Rare actinomycetes Nocardia caishijiensis and Pseudonocardia carboxydivorans as endophytes, their bioactivity and metabolites evaluation.

    PubMed

    Tanvir, Rabia; Sajid, Imran; Hasnain, Shahida; Kulik, Andreas; Grond, Stephanie

    2016-04-01

    Two strains identified as Nocardia caishijiensis (SORS 64b) and Pseudonocardia carboxydivorans (AGLS 2) were isolated as endophytes from Sonchus oleraceus and Ageratum conyzoides respectively. The analysis of their extracts revealed them to be strongly bioactive. The N. caishijiensis extract gave an LC50 of 570 μg/ml(-1) in the brine shrimp cytotoxicity assay and an EC50 of 0.552 μg/ml(-1) in the DPPH antioxidant assay. Antimicrobial activity was observed against Methicillin resistant Staphlococcus aureus (MRSA) and Escherichia coli ATCC 25922 (14 mm), Klebsiella pneumoniae ATCC 706003 (13 mm), S. aureus ATCC 25923 (11 mm) and Candida tropicalis (20 mm). For the extract of P. carboxydivorans the EC50 was 0.670 μg/ml(-1) and it was observed to be more bioactive against Bacillus subtilis DSM 10 ATCC 6051 (21 mm), C. tropicalis (20 mm), S. aureus ATCC 25923 (17 mm), MRSA (17 mm), E. coli K12 (W1130) (16 mm) and Chlorella vulgaris (10 mm). The genotoxicity testing revealed a 20 mm zone of inhibition against the polA mutant strain E. coli K-12 AB 3027 suggesting damage to the DNA and polA genes. The TLC and bioautography screening revealed a diversity of active bands of medium polar and nonpolar compounds. Metabolite analysis by HPLC-DAD via UV/vis spectral screening suggested the possibility of stenothricin and bagremycin A in the mycelium extract of N. caishijiensis respectively. In the broth and mycelium extract of P. carboxydivorans borrelidin was suggested along with α-pyrone. The HPLC-MS revealed bioactive long chained amide derivatives such as 7-Octadecenamide, 9, 12 octadecandienamide. This study reports the rare actinomycetes N. caishijiensis and P. carboxydivorans as endophytes and evaluates their bioactive metabolites.

  16. Determination of the Residual Anthracene Concentration in Cultures of Haloalkalitolerant Actinomycetes by Excitation Fluorescence, Emission Fluorescence, and Synchronous Fluorescence: Comparative Study.

    PubMed

    Lara-Severino, Reyna Del Carmen; Camacho-López, Miguel Ángel; García-Macedo, Jessica Marlene; Gómez-Oliván, Leobardo M; Sandoval-Trujillo, Ángel H; Isaac-Olive, Keila; Ramírez-Durán, Ninfa

    2016-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are compounds that can be quantified by fluorescence due to their high quantum yield. Haloalkalitolerant bacteria tolerate wide concentration ranges of NaCl and pH. They are potentially useful in the PAHs bioremediation of saline environments. However, it is known that salinity of the sample affects fluorescence signal regardless of the method. The objective of this work was to carry out a comparative study based on the sensitivity, linearity, and detection limits of the excitation, emission, and synchronous fluorescence methods, during the quantification of the residual anthracene concentration from the following haloalkalitolerant actinomycetes cultures Kocuria rosea, Kocuria palustris, Microbacterium testaceum, and 4 strains of Nocardia farcinica, in order to establish the proper fluorescence method to study the PAHs biodegrading capacity of haloalkalitolerant actinobacteria. The study demonstrated statistical differences among the strains and among the fluorescence methods regarding the anthracene residual concentration. The results showed that excitation and emission fluorescence methods performed very similarly but sensitivity in excitation fluorescence is slightly higher. Synchronous fluorescence using Δλ = 150 nm is not the most convenient method. Therefore we propose the excitation fluorescence as the fluorescence method to be used in the study of the PAHs biodegrading capacity of haloalkalitolerant actinomycetes.

  17. Determination of the Residual Anthracene Concentration in Cultures of Haloalkalitolerant Actinomycetes by Excitation Fluorescence, Emission Fluorescence, and Synchronous Fluorescence: Comparative Study

    PubMed Central

    Lara-Severino, Reyna del Carmen; Camacho-López, Miguel Ángel; García-Macedo, Jessica Marlene; Gómez-Oliván, Leobardo M.; Sandoval-Trujillo, Ángel H.; Isaac-Olive, Keila; Ramírez-Durán, Ninfa

    2016-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are compounds that can be quantified by fluorescence due to their high quantum yield. Haloalkalitolerant bacteria tolerate wide concentration ranges of NaCl and pH. They are potentially useful in the PAHs bioremediation of saline environments. However, it is known that salinity of the sample affects fluorescence signal regardless of the method. The objective of this work was to carry out a comparative study based on the sensitivity, linearity, and detection limits of the excitation, emission, and synchronous fluorescence methods, during the quantification of the residual anthracene concentration from the following haloalkalitolerant actinomycetes cultures Kocuria rosea, Kocuria palustris, Microbacterium testaceum, and 4 strains of Nocardia farcinica, in order to establish the proper fluorescence method to study the PAHs biodegrading capacity of haloalkalitolerant actinobacteria. The study demonstrated statistical differences among the strains and among the fluorescence methods regarding the anthracene residual concentration. The results showed that excitation and emission fluorescence methods performed very similarly but sensitivity in excitation fluorescence is slightly higher. Synchronous fluorescence using Δλ = 150 nm is not the most convenient method. Therefore we propose the excitation fluorescence as the fluorescence method to be used in the study of the PAHs biodegrading capacity of haloalkalitolerant actinomycetes. PMID:26925294

  18. Isolation of rhizospheric and roots endophytic actinomycetes from Leguminosae plant and their activities to inhibit soybean pathogen, Xanthomonas campestris pv. glycine.

    PubMed

    Mingma, Ratchanee; Pathom-aree, Wasu; Trakulnaleamsai, Savitr; Thamchaipenet, Arinthip; Duangmal, Kannika

    2014-01-01

    In this study, actinomycetes from roots and rhizospheric soils of leguminous plants were isolated using starch casein agar supplemented with antifungal and antibacterial antibiotics. Three hundred and seventeen actinomycetes were isolated with 77 isolates obtained from plant roots and 240 isolates from rhizospheric soils. Analysis of whole-organism hydrolysates showed that 289 strains were rich in the LL-isomer of diaminopimelic acid, a result consistent with their assignment to the streptomycetes. The remaining 28 strains were assigned to non-streptomycetes based on the presence of meso-isomer of diaminopimelic acid in cell wall. Sixty-four isolates (20.2%) showed antagonistic activity against soybean pathogen Xanthomonas campestris pv. glycine by agar overlay method. Isolate RM 365 showed the highest activity with an inhibition ratio of 3.79, with no inhibitory activity on the growth of Rhizobium japonicum TISTR 079, Rhizobium sp. TISTR 061 and Rhizobium sp. TISTR 063. The 16S rRNA gene sequence analysis revealed that isolate RM 365 shared 99.28% similarity to Streptomyces caeruleatus GIMN4(T) (GQ329712). In addition, isolates which contained meso-DAP were also identified by 16S rRNA gene sequence analysis. The results showed that they were members of the genus Amycolatopsis, Isoptericola, Micromonospora, Microbispora, Nocardia, Nonomuraea, Promicromonospora and Pseudonocardia.

  19. Comparative analysis of chemical constituents, antimicrobial and antioxidant activities of ethylacetate extracts of Polygonum cuspidatum and its endophytic actinomycete, Streptomyces sp. A0916.

    PubMed

    Wang, Lei; Qiu, Peng; Long, Xiu-Feng; Zhang, Shuai; Zeng, Zhi-Gang; Tian, Yong-Qiang

    2016-02-01

    The present study investigated the chemical composition of ethylacetate extracts from an endophytic actinomycete Streptomyces sp. A0916 and its host Polygonum cuspidatum. A comparative analysis of the antimicrobial and antioxidant properties of the extracts was also conducted. 32 compounds of P. cuspidatum and 23 compounds of Streptomyces sp. A0916 were isolated and identified by GC/MS. Antimicrobial activities of the extracts were evaluated using eight microbial strains (3 Gram-positive bacteria, 3 Gram-negative bacteria, and 2 fungi). The Streptomyces sp. A0916 extracts showed a wide range of antimicrobial activities and presented greater antimicrobial effectiveness than the P. cuspidatum extracts. The minimum inhibitory concentration (MIC) of Streptomyces sp. A0916 extracts against the ampicillin-resistant strain Enterococcus faecium SIIA843 was 32 μg·mL(-1). Furthermore, the extracts had greater antimicrobial effect against Gram-positive bacteria than Gram-negative bacteria. Finally, the antioxidant activity of the Streptomyces sp. A0916 extracts was equal to that of the P. cuspidatum extracts. In conclusion, our results suggest that the endophytic actinomycetes of the medicinal plants are an important source of bioactive substances.

  20. Succinate Overproduction: A Case Study of Computational Strain Design Using a Comprehensive Escherichia coli Kinetic Model.

    PubMed

    Khodayari, Ali; Chowdhury, Anupam; Maranas, Costas D

    2014-01-01

    Computational strain-design prediction accuracy has been the focus for many recent efforts through the selective integration of kinetic information into metabolic models. In general, kinetic model prediction quality is determined by the range and scope of genetic and/or environmental perturbations used during parameterization. In this effort, we apply the k-OptForce procedure on a kinetic model of E. coli core metabolism constructed using the Ensemble Modeling (EM) method and parameterized using multiple mutant strains data under aerobic respiration with glucose as the carbon source. Minimal interventions are identified that improve succinate yield under both aerobic and anaerobic conditions to test the fidelity of model predictions under both genetic and environmental perturbations. Under aerobic condition, k-OptForce identifies interventions that match existing experimental strategies while pointing at a number of unexplored flux re-directions such as routing glyoxylate flux through the glycerate metabolism to improve succinate yield. Many of the identified interventions rely on the kinetic descriptions that would not be discoverable by a purely stoichiometric description. In contrast, under fermentative (anaerobic) condition, k-OptForce fails to identify key interventions including up-regulation of anaplerotic reactions and elimination of competitive fermentative products. This is due to the fact that the pathways activated under anaerobic condition were not properly parameterized as only aerobic flux data were used in the model construction. This study shed light on the importance of condition-specific model parameterization and provides insight on how to augment kinetic models so as to correctly respond to multiple environmental perturbations.

  1. Permeabilization of mycolic-acid-containing actinomycetes for in situ hybridization with fluorescently labelled oligonucleotide probes.

    PubMed

    Macnaughton, S J; O'Donnell, A G; Embley, T M

    1994-10-01

    The application of whole-cell hybridization using labelled oligonucleotide probes in microbial systematics and ecology is limited by difficulties in permeabilizing many Gram-positive organisms. In this investigation paraformaldehyde treatment, acid methanolysis and acid hydrolysis were evaluated as a means of permeabilizing mycolic-acid-containing actinomycetes prior to hybridization with a fluorescently labelled oligonucleotide probe designed to bind to a conserved sequence of bacterial 16S rRNA. Methods were evaluated on stationary-phase cultures of Gordona bronchialis, Mycobacterium fortuitum, Nocardia asteroides, N. brasiliensis, Rhodococcus equi, R. erythropolis, R. fascians, R. rhodochrous and Tsukamurella paurometabola, none of which could be probed following 4% (w/v) paraformaldehyde fixation. For comparison and to test the general applicability of mild acid pretreatments, Bacillus subtilis, Lactobacillus plantarum, Escherichia coli and Pseudomonas putida were also studied. The data showed that most of the mycolic-acid-containing organisms were successfully permeabilized by mild acid hydrolysis in 1 M HCl at 37 degrees C. Cells were treated for different lengths of time. In general, the mycolic-acid-containing organisms required between 30 and 50 min hydrolysis, whereas B. subtilis, E. coli and P. putida were rendered permeable in only 10 min. Interestingly, L. plantarum could not be permeabilized using acid hydrolysis even after 60 min exposure to 1 M HCl.

  2. Endophytic actinomycetes from spontaneous plants of Algerian Sahara: indole-3-acetic acid production and tomato plants growth promoting activity.

    PubMed

    Goudjal, Yacine; Toumatia, Omrane; Sabaou, Nasserdine; Barakate, Mustapha; Mathieu, Florence; Zitouni, Abdelghani

    2013-10-01

    Twenty-seven endophytic actinomycete strains were isolated from five spontaneous plants well adapted to the poor sandy soil and arid climatic conditions of the Algerian Sahara. Morphological and chemotaxonomical analysis indicated that twenty-two isolates belonged to the Streptomyces genus and the remaining five were non-Streptomyces. All endophytic strains were screened for their ability to produce indole-3-acetic acid (IAA) in vitro on a chemically defined medium. Eighteen strains were able to produce IAA and the maximum production occurred with the Streptomyces sp. PT2 strain. The IAA produced was further extracted, partially purified and confirmed by thin layer chromatography (TLC) analysis. The 16S rDNA sequence analysis and phylogenetic studies indicated that strain PT2 was closely related to Streptomyces enissocaecilis NRRL B 16365(T), Streptomyces rochei NBRC 12908(T) and Streptomyces plicatus NBRC 13071(T), with 99.52 % similarity. The production of IAA was affected by cultural conditions such as temperature, pH, incubation period and L-tryptophan concentration. The highest level of IAA production (127 μg/ml) was obtained by cultivating the Streptomyces sp. PT2 strain in yeast extract-tryptone broth supplemented with 5 mg L-tryptophan/ml at pH 7 and incubated on a rotary shaker (200 rpm) at 30 °C for 5 days. Twenty-four-hour treatment of tomato cv. Marmande seeds with the supernatant culture of Streptomyces sp. PT2 that contained the crude IAA showed the maximum effect in promoting seed germination and root elongation.

  3. Cryptoendolithic actinomycetes from antarctic sandstone rock samples: Micromonospora endolithica sp. nov. and two isolates related to Micromonospora coerulea Jensen 1932.

    PubMed

    Hirsch, Peter; Mevs, Udo; Kroppenstedt, Reiner M; Schumann, Peter; Stackebrandt, Erko

    2004-03-01

    Three cryptoendolithic, aerobic actinomycetes (AA-459T, AA-319 and AA-321) from antarctic sandstone were characterised phenotypically and by molecular taxonomic methods. The isolates had single spores on substrate mycelium, meso-diaminopimelic acid (m-DAP) and glycine (cell wall type II), a whole cell sugar pattern D (galactose, xylose, arabinose, glucose or rhamnose) and phospholipids of type PII (diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol). Their predominant fatty acids were iso-16:0 and iso-15:0 or 17:1omega8c, the menaquinone profile was complex with mainly MK10 (H4) and MK10 (H6). A wide variety of sugars and several acids were utilised for growth. The isolates were sensitive to a few antibiotics, but formation and excretion of antibiotics was not observed. Phenotypically, isolates AA-319 and AA-321 were similar. Phylogenetic analysis of 16S rRNA gene sequences revealed close relationship of strains AA-319 and AA-321 with each other (99.5%) and clustering (98.5%) with Micromonospora coerulea DSM 43143T. DNA-DNA hybridisation showed both strains to be genomically highly similar to strain DSM 43143T. Phenotypically they could be viewed as separate taxa, but presently they will be considered as strains of Micromonospora coerulea. Strain AA-459T was phylogenetically close to Micromonospora chersina DSM 44151T (99.1%) and to Micromonospora rosaria DSM 803T, but DNA-DNA similarity with M. chersina DSM 44151T was low with 28.9/33.5 %, indicating the presence of a different and new species. Consequently, isolate AA-459T (DSM 44398T NRRL B-24248T) is described as the type strain of Micromonospora endolithica sp. nov.

  4. [Biosynthetic study of actinomycetes-metabolites for creating novel analogs].

    PubMed

    Ito, Takuya

    2013-01-01

    The aminocyclitol family is a relatively new class of natural products such as gentamicin, kanamycin, and streptomycin, which have been used clinically for decades as potent antimicrobial agents. These secondary metabolites are chiefly produced by microorganisms, especially Actinomycetes. Their chemical structures most commonly contain a C7N unit, 2-epi-5-epi-valiolone or 3-amino-5-hydroxybenzoic acid (3,5-AHBA) which are known to be responsible for their biological activities. In the course of current study, the biosynthesis of the C7N-containing metabolites, validamycin and acarbose, pactamycin, have been evaluated. We studied N-formamide salicylic acid (FSA) moiety which is a C7N unit synthesized from tryptophan by microorganisms. A strong antifungal agent antimycin, isolated from several Streptomyces sp., contains an FSA moiety, and constitutes a unique nine-membered dilactone ring with L-threonine, short-chain fatty acid, and an amide linkage connecting it to an FSA moiety. Also, an antitumor antibiotic asukamycin, produced by Streptomyces nodosus subsp. asukaensis ATCC 29757, consists of both 3,4-AHBA and C5N, cyclohexane ring linked to trans-triens. To improve the efficacy and reduce the toxicity of these metabolites, further structural modification is needed. Total chemical synthesis of these complex compounds is difficult. Therefore, alternative approaches are required, e.g., biosynthetic or genetic modification methods. This review presents the biosynthetic study on these compounds for creating new analogs using mutasyntheis.

  5. Actinomycetes mediated biogenic synthesis of metal and metal oxide nanoparticles: Progress and challenges.

    PubMed

    Manimaran, Manickavelu; Kannabiran, Krishnan

    2017-03-07

    Actinomycetes mediated biogenic synthesis of metal nanoparticles and their antimicrobial activities are well documented. Actinomycetes facilitate both intracellular and extracellular metal nanoparticles synthesis and are efficient candidates for the production of polydispersed, stable and ultra-small size metal nanoparticles. Secondary metabolites and new chemical entities derived from actinomycetes have not been extensively studied for the synthesis of metal/ metal oxide nanoparticles. The present review focuses on biogenic synthesis of metal nanoparticles from actinomycetes and the scope for exploring actinomycetes derived compounds (enzymes, organics acids and bioactive compounds) as metal and metal oxide reducing agents for the synthesis of desired nanoparticles. This review also focuses on challenges faced in the applications nanoparticles and the methods to synthesise biogenic metal nanoparticles with desired physiochemical properties such as ultra-small size, large surface to mass ratio, high reactivity etc. Methods to evade their toxicity and unique interactions with biological systems to improve their chance as an alternative therapeutic agent in medical and pharmaceutical industry are also discussed. This article is protected by copyright. All rights reserved.

  6. Actinomycetes from Red Sea Sponges: Sources for Chemical and Phylogenetic Diversity

    PubMed Central

    Abdelmohsen, Usama Ramadan; Yang, Chen; Horn, Hannes; Hajjar, Dina; Ravasi, Timothy; Hentschel, Ute

    2014-01-01

    The diversity of actinomycetes associated with marine sponges collected off Fsar Reef (Saudi Arabia) was investigated in the present study. Forty-seven actinomycetes were cultivated and phylogenetically identified based on 16S rRNA gene sequencing and were assigned to 10 different actinomycete genera. Eight putatively novel species belonging to genera Kocuria, Mycobacterium, Nocardia, and Rhodococcus were identified based on sequence similarity values below 98.2% to other 16S rRNA gene sequences available in the NCBI database. PCR-based screening for biosynthetic genes including type I and type II polyketide synthases (PKS-I, PKS-II) as well as nonribosomal peptide synthetases (NRPS) showed that 20 actinomycete isolates encoded each at least one type of biosynthetic gene. The organic extracts of nine isolates displayed bioactivity against at least one of the test pathogens, which were Gram-positive and Gram-negative bacteria, fungi, human parasites, as well as in a West Nile Virus protease enzymatic assay. These results emphasize that marine sponges are a prolific resource for novel bioactive actinomycetes with potential for drug discovery. PMID:24824024

  7. Actinomycetes from Red Sea sponges: sources for chemical and phylogenetic diversity.

    PubMed

    Abdelmohsen, Usama Ramadan; Yang, Chen; Horn, Hannes; Hajjar, Dina; Ravasi, Timothy; Hentschel, Ute

    2014-05-12

    The diversity of actinomycetes associated with marine sponges collected off Fsar Reef (Saudi Arabia) was investigated in the present study. Forty-seven actinomycetes were cultivated and phylogenetically identified based on 16S rRNA gene sequencing and were assigned to 10 different actinomycete genera. Eight putatively novel species belonging to genera Kocuria, Mycobacterium, Nocardia, and Rhodococcus were identified based on sequence similarity values below 98.2% to other 16S rRNA gene sequences available in the NCBI database. PCR-based screening for biosynthetic genes including type I and type II polyketide synthases (PKS-I, PKS-II) as well as nonribosomal peptide synthetases (NRPS) showed that 20 actinomycete isolates encoded each at least one type of biosynthetic gene. The organic extracts of nine isolates displayed bioactivity against at least one of the test pathogens, which were Gram-positive and Gram-negative bacteria, fungi, human parasites, as well as in a West Nile Virus protease enzymatic assay. These results emphasize that marine sponges are a prolific resource for novel bioactive actinomycetes with potential for drug discovery.

  8. Exploring the diversity and metabolic potential of actinomycetes from temperate marine sediments from Newfoundland, Canada.

    PubMed

    Duncan, K R; Haltli, B; Gill, K A; Correa, H; Berrué, F; Kerr, R G

    2015-01-01

    Marine sediments from Newfoundland, Canada were explored for biotechnologically promising Actinobacteria using culture-independent and culture-dependent approaches. Culture-independent pyrosequencing analyses uncovered significant actinobacterial diversity (H'-2.45 to 3.76), although the taxonomic diversity of biotechnologically important actinomycetes could not be fully elucidated due to limited sampling depth. Assessment of culturable actinomycete diversity resulted in the isolation of 360 actinomycetes representing 59 operational taxonomic units, the majority of which (94 %) were Streptomyces. The biotechnological potential of actinomycetes from NL sediments was assessed by bioactivity and metabolomics-based screening of 32 representative isolates. Bioactivity was exhibited by 41 % of isolates, while 11 % exhibited unique chemical signatures in metabolomics screening. Chemical analysis of two isolates resulted in the isolation of the cytotoxic metabolite 1-isopentadecanoyl-3β-D-glucopyranosyl-X-glycerol from Actinoalloteichus sp. 2L868 and sungsanpin from Streptomyces sp. 8LB7. These results demonstrate the potential for the discovery of novel bioactive metabolites from actinomycetes isolated from Atlantic Canadian marine sediments.

  9. Comparison of the Cell-Wall Composition of Morphologically Distinct Actinomycetes

    PubMed Central

    Yamaguchi, Tatsuro

    1965-01-01

    Yamaguchi, Tatsuro (The University of Tokyo, Tokyo, Japan). Comparison of the cell-wall composition of morphologically distinct actinomycetes. J. Bacteriol. 89:444–453. 1965.—Cell-wall composition of various morphologically distinct actinomycetes was studied to determine the relationship, if any, between cell-wall composition and morphological criteria in actinomycete taxonomy. The methods used were similar to those of Cummins and Harris. At least five types of cell-wall composition were obtained; however, these were not always correlated with groupings by the conventional classification system. For instance, the sporangium-forming actinomycetes, Actinoplanaceae, had three types of cell-wall composition; the composition of cell walls of Promicromonospora, Micromonospora, and Microbispora was the same as, or similar to, that of Actinomyces, Actinoplanes, and Streptosporangium, respectively; Chainia, Actinopycnidium, Actinosporangium, and Microellobosporia had the same cell-wall composition as Streptomyces, whereas that of Streptoverticillium was slightly different. Possible implications of cell-wall composition and morphological differentiation of hyphae for the taxonomy and phylogeny of actinomycetes are also discussed. PMID:14255713

  10. Geomechanical Modeling to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Gomez, S. P.; Sobolik, S. R.; Matteo, E. N.; Dewers, T. A.; Taha, M. R.; Stormont, J. C.

    2013-12-01

    A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. For the DOE-NETL project 'Wellbore Seal Repair Using Nanocomposite Materials,' we are especially interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Building on existing thermo-hydro-mechanical (THM) finite element modeling of wellbore casings subject to significant tensile and shear loads, we advance a conceptual and numerical methodology to assess responses of annulus cement and casing. Bench-scale models complement bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. Field scale models use the stratigraphy from a pilot CO2 injection operation to estimate the necessary mechanical properties needed for a successful repair material. We report on approaches used for adapting existing wellbore models and share preliminary results of field scale models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND Number: 2013-6241A.

  11. SMET: systematic multiple enzyme targeting - a method to rationally design optimal strains for target chemical overproduction.

    PubMed

    Flowers, David; Thompson, R Adam; Birdwell, Douglas; Wang, Tsewei; Trinh, Cong T

    2013-05-01

    Identifying multiple enzyme targets for metabolic engineering is very critical for redirecting cellular metabolism to achieve desirable phenotypes, e.g., overproduction of a target chemical. The challenge is to determine which enzymes and how much of these enzymes should be manipulated by adding, deleting, under-, and/or over-expressing associated genes. In this study, we report the development of a systematic multiple enzyme targeting method (SMET), to rationally design optimal strains for target chemical overproduction. The SMET method combines both elementary mode analysis and ensemble metabolic modeling to derive SMET metrics including l-values and c-values that can identify rate-limiting reaction steps and suggest which enzymes and how much of these enzymes to manipulate to enhance product yields, titers, and productivities. We illustrated, tested, and validated the SMET method by analyzing two networks, a simple network for concept demonstration and an Escherichia coli metabolic network for aromatic amino acid overproduction. The SMET method could systematically predict simultaneous multiple enzyme targets and their optimized expression levels, consistent with experimental data from the literature, without performing an iterative sequence of single-enzyme perturbation. The SMET method was much more efficient and effective than single-enzyme perturbation in terms of computation time and finding improved solutions.

  12. Self-resistance mechanisms of actinomycetes producing lipid II-targeting antibiotics.

    PubMed

    Stegmann, Evi; Frasch, Hans-Joerg; Kilian, Regina; Pozzi, Roberta

    2015-02-01

    Glycopeptides and several lantibiotics are lipid II-targeting antibiotics produced by actinomycetes. To protect themselves from their own product, antibiotic producers developed self-resistance mechanisms. Inspection of different producer strains revealed that their resistance is not only based on a single determinant but on the synergistic action of different factors. Glycopeptide producers possess different ways to synthesize a modified peptidoglycan to prevent the binding of the glycopeptide antibiotic. One possible modification is the synthesis of peptidoglycan precursors terminating with a D-alanyl-D-lactate (D-Ala-D-Lac) rather than with a D-alanyl-D-alanine (D-Ala-D-Ala) resulting in a 1000-fold decreased binding affinity of the glycopeptide to its target. The reprogramming of the peptidoglycan precursor biosynthesis is based on the action of VanHAX or paralogous enzymes as it was shown for Amycolatopsis balhimycina. A second peptidoglycan modification resulting in glycopeptide resistance was investigated in the glycopeptide A40926 producer Nonomuraea ATCC 39727. Nonomuraea eliminates the glycopeptide target by synthesizing a peptidoglycan with 3-3 cross-linked peptide stems. The carboxypeptidase VanYn provides tetrapeptides which serve as substrates for the L,D-transpeptidase catalyzing the formation of 3-3 cross-links. The occurrence of 3-3 cross-linked dimers is also an important feature of the lantibiotic NAI-107 producer Microbispora ATCC PTA-5024. Moreover, the D-Ala in the fourth position in the acceptor peptide of muropeptides is exchanged to glycine or serine in Microbispora, a side reaction of the L,D-transpeptidase. Together with the lipoprotein MlbQ, the ABC transporter MlbYZ and the transmembrane protein MlbJ it might contribute to the self-resistance in Microbispora ATCC PTA-5024.

  13. Phylogenetic characterization of culturable actinomycetes associated with the mucus of the coral Acropora digitifera from Gulf of Mannar.

    PubMed

    Nithyanand, Paramasivam; Manju, Sivalingam; Karutha Pandian, Shunmugiah

    2011-01-01

    The marine environment is a virtually untapped source of novel actinomycete diversity and its metabolites. Investigating the diversity of actinomycetes in other marine macroorganisms, like seaweeds and sponges, have resulted in isolation of novel bioactive metabolites. Actinomycetes diversity associated with corals and their produced metabolites have not yet been explored. Hence, in this study we attempted to characterize the culturable actinomycetes population associated with the coral Acropora digitifera. Actinomycetes were isolated from the mucus of the coral wherein the actinomycetes count was much higher when compared with the surrounding seawater and sediment. Actinobacteria-specific 16S rRNA gene primers were used for identifying the isolates at the molecular level in addition to biochemical tests. Amplified ribosomal DNA restriction analysis using three restriction enzymes revealed several polymorphic groups within the isolates. Sequencing and blast analysis of the isolates revealed that some isolates had only 96.7% similarity with its nearest match in GenBank indicating that they may be novel isolates at the species level. The isolated actinomycetes exhibited good antibacterial activity against various human pathogens. This study offers for the first time a prelude about the unexplored culturable actinomycetes diversity associated with a scleractinian coral and their bioactive capabilities.

  14. Application of nitroarene dioxygenases in the design of novel strains that degrade chloronitrobenzenes

    PubMed Central

    Ju, Kou‐San; Parales, Rebecca E.

    2009-01-01

    Summary Widespread application of chloronitrobenzenes as feedstocks for the production of industrial chemicals and pharmaceuticals has resulted in extensive environmental contamination with these toxic compounds, where they pose significant risks to the health of humans and wildlife. While biotreatment in general is an attractive solution for remediation, its effectiveness is limited with chloronitrobenzenes due to the small number of strains that can effectively mineralize these compounds and their ability to degrade only select isomers. To address this need, we created engineered strains with a novel degradation pathway that reduces the total number of steps required to convert chloronitrobenzenes into compounds of central metabolism. We examined the ability of 2‐nitrotoluene 2,3‐dioxygenase from Acidovorax sp. strain JS42, nitrobenzene 1,2‐dioxygenase (NBDO) from Comamonas sp. strain JS765, as well as active‐site mutants of NBDO to generate chlorocatechols from chloronitrobenzenes, and identified the most efficient enzymes. Introduction of the wild‐type NBDO and the F293Q variant into Ralstonia sp. strain JS705, a strain carrying the modified ortho pathway for chlorocatechol metabolism, resulted in bacterial strains that were able to sustainably grow on all three chloronitrobenzene isomers without addition of co‐substrates or co‐inducers. These first‐generation engineered strains demonstrate the utility of nitroarene dioxygenases in expanding the metabolic capabilities of bacteria and provide new options for improved biotreatment of chloronitrobenzene‐contaminated sites. PMID:21261918

  15. Utilization of Genomic Variations Among Xylella fastidiosa Strains for Improved Diagnostic Design

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Gram-negative, xylem-limited phytopathogenic bacterium Xylella fastidiosa causes economically important diseases in grapevine, citrus and many other plant species. Our recent whole genome comparative analysis of the four sequenced strains has identified genomic variation among these strains. The...

  16. Actinomadura syzygii sp. nov., an endophytic actinomycete isolated from the roots of a jambolan plum tree (Syzygium cumini L. Skeels).

    PubMed

    Rachniyom, Hathairat; Matsumoto, Atsuko; Indananda, Chantra; Duangmal, Kannika; Takahashi, Yoko; Thamchaipenet, Arinthip

    2015-06-01

    The taxonomic position of an endophytic actinomycete, strain GKU 157T, isolated from the roots of a jambolan plum tree (Syzygium cumini L. Skeels) collected at Khao Khitchakut National Park, Chantaburi province, Thailand, was determined using a polyphasic taxonomic approach. 16S rRNA gene sequence analysis revealed that strain GKU 157T belongs to the genus Actinomadura and formed a distinct phyletic line with Actinomadura chibensis NBRC 106107T (98.6 % similarity). Strain GKU 157T formed an extensively branched, non-fragmenting substrate mycelium and aerial hyphae that differentiated into hooked to short spiral chains of about 20 non-motile spores with a warty surface. The cell wall contained meso-diaminopimelic acid and the whole-cell sugars were galactose, glucose, madurose, mannose and ribose. The N-acyl type of muramic acid was acetyl. Mycolic acids were absent. The phospholipids included phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylinositol (PI), phosphatidylinositolmannoside (PIM) and two unknown phospholipids (PLs). The major menaquinone was MK-9(H6) and the predominant fatty acids were C16:0, iso-C16:0, C18:1ω9c, C18:0 and 10-methyl C18:0 (tuberculostearic acid). The genomic DNA G+C content was 73.1 mol%. A combination of DNA-DNA hybridization results and significant differences from related species in cultural, physiological and chemical characteristics indicated that strain GKU 157T represents a novel species of the genus Actinomadura, for which the name Actinomadura syzygii sp. nov. is proposed. The type strain is GKU 157T ( = BCC 70456T = NBRC 110399T).

  17. Construction of a natural product library containing secondary metabolites produced by actinomycetes.

    PubMed

    Takagi, Motoki; Shin-Ya, Kazuo

    2012-09-01

    To construct a natural product library for drug screening, we isolated secondary metabolites from a wide variety of actinomycetes cultured from marine sponges. The results suggested that marine sponges are a promising source of actinomycetes with the potential to produce new metabolites. Furthermore, we evaluated the chemical space occupied by our natural product library (CB library) by multidimensional principal component analysis and compared it with a commercially available compound library (ZINC library), which was randomly selected from the ZINC library (approximately 30 000 000 compounds). The CB library occupied a wider chemical space than the ZINC library. Bioactive compounds in the CB library possessed a wide chemical space that was not covered by ZINC library. These results indicate that the CB library mainly comprises secondary metabolites from actinomycetes, and it has great potential as a source of compounds for drug screening.

  18. Larvicidal potential of Asteraceae family endophytic actinomycetes against Culex quinquefasciatus mosquito larvae.

    PubMed

    Tanvir, Rabia; Sajid, Imran; Hasnain, Shahida

    2014-01-01

    Pakistan is blessed with plants of Asteraceae family with known medicinal background used for centuries by Hakims (traditional physicians). Keeping in mind the background of their anti-larval potential, a total of 21 endophytic actinomycetes were isolated from four Asteraceae plants and screened against the first and fourth instar stages of Culex quinquefasciatus Say mosquito larvae. Of the 21 isolates, 6 of them gave strong larvicidal activity (80-100% mortality) in the screening results and 4 isolates gave a potent larvicidal activity (100% mortality) at the fourth instar stage. These isolates belonged to different species within the actinomycetes group, namely Streptomyces albovinaceus and Streptomyces badius. This communication reports the larvicidal potential of endophytic actinomycetes residing within the native Asteraceae plants in Pakistan. The study suggests further exploration through large-scale productions leading to the identification of the larvicidal compounds.

  19. Ecological and Taxonomic Features of Actinomycetal Complexes in Soils of the Lake Elton Basin

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Dubrova, M. S.; Kuznetsova, A. I.; Gracheva, T. A.; Manucharova, N. A.; Zvyagintsev, D. G.

    2016-02-01

    In the sor (playa) solonchaks of chloride and sulfate-chloride salinity (the content of readily soluble salts is 0.9-1.0%) in the delta of the Khara River discharging into Lake Elton, the number of mycelial actinobacteria (actinomycetes) is low ((2-3) × 103 CFU/g of soil). At a distance from the water's edge, these soils are substituted for the light chestnut ones, for which an elevated number of actinomycetes (an order of magnitude higher than in the sor solonchaks) and a wider generic spectrum are characteristic. The actinomycetal complex is included the Streptomyces and Micromonospora genera, whereas in the sor solonchaks around the lake, representatives of Micromonospora were not found.

  20. Actinomycetal complexes in drained peat soils of the taiga zone upon pyrogenic succession

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Glushkova, N. A.; Bannikov, M. V.; Shvarov, A. P.; Pozdnyakov, A. I.; Zvyagintsev, D. G.

    2008-04-01

    The number and diversity of actinomycetes in peat soils vary in dependence on the stage of pyrogenic succession. In the cultivated peat soil, the number of actinomycetes after fires decreases by three-four times, mainly at the expense of acidophilic and neutrophilic groups. An increase in the number of mycelial prokaryotes (at the expense of alkaliphilic forms) is seen on the fifth year of functioning of the pyrogenic peat soil. The species diversity of streptomycetes in peat soils also decreases after fires. An increase in the range of streptomycetal species at the expense of neutrophilic and alkaliphilic forms takes place on the fifth year of the pyrogenic succession. Parameters of the actinomycetal complex—the population density, species composition, and ecological features—are the criteria whose changes allow us to judge the state of peat soils in the course of their pyrogenic succession.

  1. Constraint-based strain design using continuous modifications (CosMos) of flux bounds finds new strategies for metabolic engineering.

    PubMed

    Cotten, Cameron; Reed, Jennifer L

    2013-05-01

    In recent years, a growing number of metabolic engineering strain design techniques have employed constraint-based modeling to determine metabolic and regulatory network changes which are needed to improve chemical production. These methods use systems-level analysis of metabolism to help guide experimental efforts by identifying deletions, additions, downregulations, and upregulations of metabolic genes that will increase biological production of a desired metabolic product. In this work, we propose a new strain design method with continuous modifications (CosMos) that provides strategies for deletions, downregulations, and upregulations of fluxes that will lead to the production of the desired products. The method is conceptually simple and easy to implement, and can provide additional strategies over current approaches. We found that the method was able to find strain design strategies that required fewer modifications and had larger predicted yields than strategies from previous methods in example and genome-scale networks. Using CosMos, we identified modification strategies for producing a variety of metabolic products, compared strategies derived from Escherichia coli and Saccharomyces cerevisiae metabolic models, and examined how imperfect implementation may affect experimental outcomes. This study gives a powerful and flexible technique for strain engineering and examines some of the unexpected outcomes that may arise when strategies are implemented experimentally.

  2. Exposure to moulds and actinomycetes in Alpine farms: a nested environmental study of the PASTURE cohort.

    PubMed

    Roussel, S; Sudre, B; Reboux, G; Waser, M; Buchele, G; Vacheyrou, M; Dalphin, J C; Millon, L; Braun-Fahrländer, C; von Mutius, E; Piarroux, R

    2011-08-01

    Several studies have suggested that children exposed to a farm environment are protected against allergies and asthma. The present work is an environmental study nested within the PASTURE cohort and includes 97 farmers and 74 non-farmers in three regions of the Alpine Arc (Switzerland, France and Germany). The objectives were to determine and compare the fungi and actinomycetes present in farming and non-farming environments (children's bedrooms and cowsheds), and to identify the agricultural practices associated with an increase in airborne fungi and actinomycetes in cowsheds. Air samples were collected by air pump and were analysed by culture and by direct counting of spores on membranes. During their stay in bedrooms, children living on farms were exposed to significantly greater amounts of Absidia spp., Eurotium spp., Cladosporium spp., Penicillium spp. and mesophilic actinomycetes than children who did not live on farms. Depending on the season, the levels of moulds, yeasts and actinomycetes were from 14 to 82 times higher in cowsheds before feeding the cattle than in children's bedrooms, and from 12 to 464 times higher in cowsheds after feeding than in children's bedrooms. Feeding cattle in cowsheds was associated with a significant peak in airborne moulds and actinomycetes, and this peak was higher in winter than in summer. Silage distribution was associated with low amounts of moulds and actinomycetes. Other significant agricultural factors were the type of cowshed, cowshed volume, method of food distribution to cattle and use of fresh grass. An assessment of the microbiological diversity on farms and in children's rooms may help to determine the factors protecting children from asthma and atopic diseases.

  3. Effect of cadmium on soil bacteria and actinomycetes

    SciTech Connect

    Williams, S.E.; Wollum, A.G. II

    1981-04-01

    Soil procaryotic populations were evaluated from a soybean field (Glycine max L.) that had been amended 3 years previously with Cd (as CdCl/sub 2/ 2 1/2H/sub 2/O) at rates corresponding to 0, 6, 22, and 40 kg Cd/ha. Replicate aliquots of soil suspensions from the treated plots were plated on media containing increasing concentrations of Cd. This was done to determine if soil bacteria and actinomycetes (procaryotes) that were tolerant of Cd had developed in Cd-treated soils. It was found that the level of DTPA-TEA extractable soil Cd had no influence on the development of Cd-tolerant soil populations on media amended with Cd. Rather, it was found that low levels of media Cd retarded procaryote growth, whereas high levels did not. This also occurred regardless of the level of soil extractable Cd. Soil moisture at the time of sampling was found to be inversely related to procaryote numbers on media containing 0 ppM Cd and directly related on media containing 10, 20, and 40 ppM Cd. On media containing 5 ppM Cd, numbers of soil organisms were low with respect to the control and other Cd media levels and had no relationship to soil moisture. Growth rate constants of 58 pure cultured bacteria were determined at Cd concentrations of 0, 5, 10, 20, and 40 ppM in liquid media. The organisms exhibited tolerant, intolerant, and stimulated responses of Cd; however, 50% were intolerant to 5 ppM Cd but tolerant at concentrations > 5 ppM.

  4. Verrucosispora maris sp. nov., a novel deep-sea actinomycete isolated from a marine sediment which produces abyssomicins.

    PubMed

    Goodfellow, Michael; Stach, James E M; Brown, Roselyn; Bonda, Avinash Naga Venkata; Jones, Amanda L; Mexson, Joanne; Fiedler, Hans-Peter; Zucchi, Tiago Domingues; Bull, Alan T

    2012-01-01

    Verrucosispora isolate AB-18-032(T), the abyssomicin- and proximicin-producing actinomycete, has chemotaxonomic and morphological properties consistent with its classification in the genus Verrucosispora. The organism formed a distinct phyletic line in the Verrucosispora 16S rRNA gene tree sharing similarities of 99.7%, 98.7% and 98.9% with Verrucosispora gifhornensis DSM 44337(T), Verrucosispora lutea YIM 013(T) and Verrucosispora sediminis MS 426(T), respectively. It was readily distinguished from the two latter species using a range of phenotypic features and from V. gifhornensis DSM 44337(T), its nearest phylogenetic neighbor, by a DNA G+C content of 65.5 mol% obtained by thermal denaturation and fluorometry and DNA:DNA relatedness values of 64.0% and 65.0% using renaturation and fluorometric methods, respectively. It is apparent from the combined genotypic and phenotypic data that strain AB-18-032(T) should be classified in the genus Verrucosispora as a new species. The name Verrucosispora maris sp. nov. is proposed for this taxon with isolate AB-18-032(T) (= DSM 45365(T) = NRRL B-24793(T)) as the type strain.

  5. Crystallochemical transformation of phyllosilicates under the impact of cyanobacteria and actinomycetes

    NASA Astrophysics Data System (ADS)

    Chizhikova, N. P.; Omarova, E. O.; Lobakova, E. S.; Zenova, G. M.; Manucharov, A. S.

    2009-01-01

    The transformation of the crystallochemical structure of phyllosilicates (vermiculite and biotite) under the impact of growing cyanobacterial and actinomycetal associations, as well as monocultures of cyanobacteria and actinomycetes, has been studied. The character of the mineral transformation depends on their crystallochemical structure and the type of biota. The most significant changes take place in the contact zone between minerals and microbial associations; the effect of microbial monocultures is smaller. The transformation of biotite proceeds via the stage of ordered mica-vermiculite (smectite) neoformation (rectorite); the destruction of vermiculite has been identified.

  6. Marinactinones A-C, new γ-pyrones from marine actinomycete Marinactinospora thermotolerans SCSIO 00606.

    PubMed

    Wang, Fazuo; Tian, Xinpeng; Huang, Caiguo; Li, Qingxin; Zhang, Si

    2011-02-01

    Three new γ-pyrones named marinactinones A-C (1-3) were isolated from marine-derived actinomycete Marinactinospora thermotolerans SCSIO 00606. These structures were elucidated by extensive spectroscopic methods. All three new compounds were evaluated for cytotoxic effects on six cancer cell lines and inhibitory activities of DNA topoisomerase II. Compounds 1-3 exhibited moderate cytotoxicities against SW1990, HepG2 and SMCC-7721 cell lines, and compound 2 showed weak DNA topoisomerase II inhibition activity. This is the first report on the chemical constituents and their biological activities from Marinactinospora, a novel genus of marine actinomycetes.

  7. Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levels.

    PubMed

    Yuan, Rong; Tsaih, Shirng-Wern; Petkova, Stefka B; Marin de Evsikova, Caralina; Xing, Shuqin; Marion, Michael A; Bogue, Molly A; Mills, Kevin D; Peters, Luanne L; Bult, Carol J; Rosen, Clifford J; Sundberg, John P; Harrison, David E; Churchill, Gary A; Paigen, Beverly

    2009-06-01

    To better characterize aging in mice, the Jackson Aging Center carried out a lifespan study of 31 genetically-diverse inbred mouse strains housed in a specific pathogen-free facility. Clinical assessments were carried out every 6 months, measuring multiple age-related phenotypes including neuromuscular, kidney and heart function, body composition, bone density, hematology, hormonal levels, and immune system parameters. In a concurrent cross-sectional study of the same 31 strains at 6, 12, and 20 months, more invasive measurements were carried out followed by necropsy to assess apoptosis, DNA repair, chromosome fragility, and histopathology. In this report, which is the initial paper of a series, the study design, median lifespans, and circulating insulin-like growth factor 1 (IGF1) levels at 6, 12, and 18 months are described for the first cohort of 32 females and 32 males of each strain. Survival curves varied dramatically among strains with the median lifespans ranging from 251 to 964 days. Plasma IGF1 levels, which also varied considerably at each time point, showed an inverse correlation with a median lifespan at 6 months (R = -0.33, P = 0.01). This correlation became stronger if the short-lived strains with a median lifespan < 600 days were removed from the analysis (R = -0.53, P < 0.01). These results support the hypothesis that the IGF1 pathway plays a key role in regulating longevity in mice and indicates that common genetic mechanisms may exist for regulating IGF1 levels and lifespan.

  8. Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levels

    PubMed Central

    Yuan, Rong; Tsaih, Shirng-Wern; Petkova, Stefka B.; de Evsikova, Caralina Marin; Xing, Shuqin; Marion, Michael A.; Bogue, Molly A.; Mills, Kevin D.; Peters, Luanne L.; Bult, Carol J.; Rosen, Clifford J.; Sundberg, John P.; Harrison, David E.; Churchill, Gary A.; Paigen, Beverly

    2009-01-01

    Summary To better characterize aging in mice, the Jackson Aging Center carried out a lifespan study of 31 genetically-diverse inbred mouse strains housed in a specific pathogen-free facility. We carried out clinical assessments every 6 months, measuring multiple age-related phenotypes including neuromuscular, kidney and heart function, body composition, bone density, hematology, hormonal levels, and immune system parameters. In a concurrent cross-sectional study of the same 31 strains at 6, 12, and 20 months, we carried out more invasive measurements followed by necropsy to assess apoptosis, DNA repair, chromosome fragility, and histopathology. In this report, which is the initial paper of a series, we describe the study design, median lifespans, and circulating IGF1 levels at 6, 12 and 18 months for the first cohort of 32 females and 32 males of each strain. Survival curves varied dramatically among strains with median lifespans ranging from 251 to 964 days. Plasma IGF1 levels, which also varied considerably at each time point, showed an inverse correlation with median lifespan at 6 months (R=−0.33, P=0.01). This correlation became stronger if the short-lived strains with a median lifespan<600 days were removed from the analysis (R=−0.53, P<0.01). These results support the hypothesis that the IGF1 pathway plays a key role in regulating longevity in mice and indicates that common genetic mechanisms may exist for regulating IGF1 levels and lifespan. PMID:19627267

  9. Adsorption by design: Tuning atom-graphene van der Waals interactions via mechanical strain

    NASA Astrophysics Data System (ADS)

    Nichols, Nathan S.; Del Maestro, Adrian; Wexler, Carlos; Kotov, Valeri N.

    2016-05-01

    We aim to understand how the van der Waals force between neutral adatoms and a graphene layer is modified by uniaxial strain and electron correlation effects. A detailed analysis is presented for three atoms (He, H, and Na) and graphene strain ranging from weak to moderately strong. We show that the van der Waals potential can be significantly enhanced by strain, and present applications of our results to the problem of elastic scattering of atoms from graphene. In particular, we find that quantum reflection can be significantly suppressed by strain, meaning that dissipative inelastic effects near the surface become of increased importance. Furthermore, we introduce a method to independently estimate the Lennard-Jones parameters used in an effective model of He interacting with graphene, and determine how they depend on strain. At short distances, we find that strain tends to reduce the interaction strength by pushing the location of the adsorption potential minima to higher distances above the deformed graphene sheet. This opens up the exciting possibility of mechanically engineering an adsorption potential, with implications for the formation and observation of anisotropic low-dimensional superfluid phases.

  10. Strain measurement of objects subjected to aerodynamic heating using digital image correlation: Experimental design and preliminary results

    NASA Astrophysics Data System (ADS)

    Pan, Bing; Jiang, Tianyun; Wu, Dafang

    2014-11-01

    In thermomechanical testing of hypersonic materials and structures, direct observation and quantitative strain measurement of the front surface of a test specimen directly exposed to severe aerodynamic heating has been considered as a very challenging task. In this work, a novel quartz infrared heating device with an observation window is designed to reproduce the transient thermal environment experienced by hypersonic vehicles. The specially designed experimental system allows the capture of test article's surface images at various temperatures using an optical system outfitted with a bandpass filter. The captured images are post-processed by digital image correlation to extract full-field thermal deformation. To verify the viability and accuracy of the established system, thermal strains of a chromiumnickel austenite stainless steel sample heated from room temperature up to 600 °C were determined. The preliminary results indicate that the air disturbance between the camera and the specimen due to heat haze induces apparent distortions in the recorded images and large errors in the measured strains, but the average values of the measured strains are accurate enough. Limitations and further improvements of the proposed technique are discussed.

  11. Strain measurement of objects subjected to aerodynamic heating using digital image correlation: experimental design and preliminary results.

    PubMed

    Pan, Bing; Jiang, Tianyun; Wu, Dafang

    2014-11-01

    In thermomechanical testing of hypersonic materials and structures, direct observation and quantitative strain measurement of the front surface of a test specimen directly exposed to severe aerodynamic heating has been considered as a very challenging task. In this work, a novel quartz infrared heating device with an observation window is designed to reproduce the transient thermal environment experienced by hypersonic vehicles. The specially designed experimental system allows the capture of test article's surface images at various temperatures using an optical system outfitted with a bandpass filter. The captured images are post-processed by digital image correlation to extract full-field thermal deformation. To verify the viability and accuracy of the established system, thermal strains of a chromiumnickel austenite stainless steel sample heated from room temperature up to 600 °C were determined. The preliminary results indicate that the air disturbance between the camera and the specimen due to heat haze induces apparent distortions in the recorded images and large errors in the measured strains, but the average values of the measured strains are accurate enough. Limitations and further improvements of the proposed technique are discussed.

  12. Design and validation of high-precision wireless strain sensors for structural health monitoring of steel structures

    NASA Astrophysics Data System (ADS)

    Jo, Hongki; Park, JongWoong; Spencer, B. F., Jr.; Jung, Hyung-Jo

    2012-04-01

    Due to their cost-effectiveness and ease of installation, smart wireless sensors have received considerable recent attention for structural health monitoring of civil infrastructure. Though various wireless smart sensor networks (WSSN) have been successfully implemented for full-scale structural health monitoring (SHM) applications, monitoring of low-level ambient strain still remains a challenging problem for wireless smart sensors (WSS) due to A/D converter resolution, inherent circuit noise, and the need for automatic operation. In this paper, the design and validation of high-precision strain sensor board for Imote2 WSS platform and its application to SHM of a cable-stayed bridge are presented. By accurate and automated balancing the Wheatstone bridge, signal amplification of up to 2507-times can be obtained. Temperature compensation and shunt calibration are implemented. In addition to traditional foil-type strain gages, the sensor board has been designed to accommodate a friction-type magnet strain sensor, facilitating fast and easy deployment. The sensor board has been calibrated using lab-scale tests, and then deployed on a full-scale cable-stayed bridge to verify its performance.

  13. Design and optimisation of suspended strained germanium membranes for near-infrared lasing (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Burt, Daniel; Aldeek, Waseem; Aldaghri, Osamah A.; Ikonic, Zoran; Querin, Oswaldo M.; Kelsall, Robert W.

    2016-05-01

    The development of a semiconductor laser compatible with silicon substrates and high-volume silicon integrated circuit manufacturing is a key requirement for monolithic silicon photonic transceivers. Tensile strained germanium is a promising material system which meets these criteria, and both optically pumped and electrically injected lasing have been reported[1,2]. It is well established that growth of thick (~1 micron) layers of germanium on silicon substrates by two-stage chemical vapour deposition followed by thermal annealing results in nearly-relaxed germanium with a residual biaxial tensile strain of typically 0.15-0.25% [3]. Several researchers have investigated methods of amplifying this built-in strain in order to increase the attainable optical gain. Increased uniaxial strain levels have been demonstrated in suspended linear bridge structures created by wet chemical underetching. However, uniaxial strain is less effective than biaxial strain in converting germanium from an indirect to a direct gap semiconductor and hence generating substantial optical gain. In this work, we have computationally investigated and optimised two-dimensional patterning and under-etching of germanium membranes in order to achieve biaxial strain amplification. Strain simulations were carried out using finite element methods and the shape of the suspended germanium structures was optimised to achieve the highest tensile strain whilst remaining below the empirically determined yield strength of the thin membranes. The net optical gain distribution across the membrane was calculated using 8 band k.p bandstructure to determine the full interband gain, the inter-valence-band absorption and the intervalley and intravalley phonon- and impurity-assisted free carrier absorption. Band-gap narrowing effects were included using empirical data. Biaxial strain values of ~1% can be achieved in the lasing region of the structure, which, although below the level required to convert germanium

  14. Streptomyces tritolerans sp. nov., a novel actinomycete isolated from soil in Karnataka, India.

    PubMed

    Syed, Dastager G; Agasar, Dayanand; Kim, Chang-Jin; Li, Wen-Jun; Lee, Jae-Chan; Park, Dong-Jin; Xu, Li-Hua; Tian, Xin-Peng; Jiang, Cheng-Lin

    2007-11-01

    A Gram-positive, nonmotile, moderately halophilic, alkali and thermotolerant strain designated DAS 165(T), was isolated from a dry land soil sample from the Gulbarga region, Karnataka province, India. The isolate produced yellow substrate mycelia and gray aerial mycelia on most tested media. Strain DAS 165(T) showed growth in the presence of 5 to 7% NaCl and at 45 degrees C. The DNA G + C content was 69.7%. 16S rRNA gene sequence analysis together with these characteristics consistently assigned strain DAS 165(T) to the genus Streptomyces. The 16S rRNA gene sequence analysis revealed that strain DAS 165(T) was most closely related to S. tendae ATCC 19812(T) (D 63873) with a sequence similarity of 99.6% (three nucleotide differences out of 1,517). Strain DAS 165(T) formed a distinct clade based on analysis of the almost complete sequence and 120-nucleotide variable gamma region of the 16S rRNA gene. Despite the high sequence similarity, strain DAS 165(T) was phenotypically different from S. tendae ATCC 19812(T). DNA-DNA hybridization between these strains was 47% showing that strain DAS 165(T) is a distinct genomic species. Phenetic and genetic results support the classification of strain DAS 165(T) as a new species, for which the name S. tritolerans is proposed, with strain DAS 165(T) as the type strain (=DSM 41899(T )= CCTCCAA 206013(T)).

  15. Draft Genome Sequence of the Lignocellulose Decomposer Thermobifida fusca Strain TM51.

    PubMed

    Tóth, Akos; Barna, Terézia; Nagy, István; Horváth, Balázs; Nagy, István; Táncsics, András; Kriszt, Balázs; Baka, Erzsébet; Fekete, Csaba; Kukolya, József

    2013-07-11

    Here, we present the complete genome sequence of Thermobifida fusca strain TM51, which was isolated from the hot upper layer of a compost pile in Hungary. T. fusca TM51 is a thermotolerant, aerobic actinomycete with outstanding lignocellulose-decomposing activity.

  16. Bioactive Secondary Metabolites with Unique Aromatic and Heterocyclic Structures Obtained from Terrestrial Actinomycetes Species.

    PubMed

    Abdelfattah, Mohamed S; Arai, Midori A; Ishibashi, Masami

    2016-07-01

    Natural products from actinomycetes are important and valuable sources for drug discovery and the development of biological tools. The present review describes our recent study on the isolation of new natural products mainly possessing heterocyclic and aromatic ring structures with biological effects on cancer-related cellular pathways such as tumor necrosis factor-α-related apoptosis-inducing ligand (TRAIL) and Wnt signaling.

  17. Draft genome sequence of Gordonia neofelifaecis NRRL B-59395, a cholesterol-degrading actinomycete.

    PubMed

    Ge, Fanglan; Li, Wei; Chen, Guiying; Liu, Yuchang; Zhang, Guangxiang; Yong, Bin; Wang, Qiong; Wang, Nan; Huang, Zhumei; Li, Weitian; Wang, Jing; Wu, Cheng; Xie, Qian; Liu, Gang

    2011-09-01

    We report a draft sequence of the genome of Gordonia neofelifaecis NRRL B-59395, a cholesterol-degrading actinomycete isolated from fresh feces of a clouded leopard (Neofelis nebulosa). As predicted, the reported genome contains several gene clusters for cholesterol degradation. This is the second available genome sequence of the family Gordoniaceae.

  18. Population densities and genetic diversity of actinomycetes associated to the rhizosphere of Theobroma cacao

    PubMed Central

    Barreto, Tâmara R.; da Silva, Augusto C.M.; Soares, Ana Cristina F.; de Souza, Jorge T.

    2008-01-01

    In spite of the acknowledged importance of growth-promoting bacteria, only a reduced number of studies were conducted with these microorganisms on Theobroma cacao. The objectives of this work were to study the population densities and genetic diversity of actinomycetes associated with the rhizosphere of cacao as a first step in their application in plant growth promotion and biological control. The populations densities of actinomycetes in soil and cacao roots were similar, with mean values of 1,0 x 106 CFU/g and 9,6 x 105 CFU/g, respectively. All isolates selected and used in this study were identified through sequencing analyses of a fragment of the rpoB gene that encodes the β-subunit of the RNA polymerase as species of the genus Streptomyces. In vitro cellulolytic, xilanolytic and chitinolytic activity, indolacetic acid production and phosphate solubilization activities were observed in most of the isolates tested. The data obtained in this study demonstrate that actinomycetes account for a higher percentage of the total population of culturable bacteria in soil than on cacao roots. Additionally, actinomycetes from the cacao rhizosphere are genetically diverse and have potential applications as agents of growth promotion. PMID:24031247

  19. Eliciting antibiotics active against the ESKAPE pathogens in a collection of actinomycetes isolated from mountain soils.

    PubMed

    Zhu, Hua; Swierstra, Jasper; Wu, Changsheng; Girard, Geneviève; Choi, Young Hae; van Wamel, Willem; Sandiford, Stephanie K; van Wezel, Gilles P

    2014-08-01

    The rapid emergence of multidrug-resistant (MDR) bacterial pathogens poses a major threat for human health. In recent years, genome sequencing has unveiled many poorly expressed antibiotic clusters in actinomycetes. Here, we report a well-defined ecological collection of >800 actinomycetes obtained from sites in the Himalaya and Qinling mountains, and we used these in a concept study to see how efficiently antibiotics can be elicited against MDR pathogens isolated recently from the clinic. Using 40 different growth conditions, 96 actinomycetes were identified - predominantly Streptomyces - that produced antibiotics with efficacy against the MDR clinical isolates referred to as ESKAPE pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and/or Enterobacter cloacae. Antimicrobial activities that fluctuated strongly with growth conditions were correlated with specific compounds, including borrelidin, resistomycin, carbomethoxy-phenazine, and 6,7,8- and 5,6,8-trimethoxy-3-methylisocoumarin, of which the latter was not described previously. Our work provided insights into the potential of actinomycetes as producers of drugs with efficacy against clinical isolates that have emerged recently and also underlined the importance of targeting a specific pathogen.

  20. Saccharothrix sp. PAL54, a new chloramphenicol-producing strain isolated from a Saharan soil.

    PubMed

    Aouiche, Adel; Sabaou, Nasserdine; Meklat, Atika; Zitouni, Abdelghani; Bijani, Christian; Mathieu, Florence; Lebrihi, Ahmed

    2012-03-01

    An actinomycete strain designated PAL54, producing an antibacterial substance, was isolated from a Saharan soil in Ghardaïa, Algeria. Morphological and chemical studies indicated that this strain belonged to the genus Saccharothrix. Analysis of the 16S rDNA sequence showed a similarity level ranging between 96.9 and 99.2% within Saccharothrix species, with S. longispora DSM 43749(T), the most closely related. DNA-DNA hybridization confirmed that strain PAL54 belonged to Saccharothrix longispora. It showed very strong activity against pathogenic Gram-positive and Gram-negative bacteria responsible for nosocomial infections and resistant to multiple antibiotics. Strain PAL54 secreted the antibiotic optimally during mid-stationary and decline phases of growth. One antibacterial compound was isolated from the culture broth and purified by HPLC. The active compound was elucidated by uv-visible and NMR spectroscopy and by mass spectrometry. The results showed that this compound was a D: (-)-threo chloramphenicol. This is the first report of chloramphenicol production by a Saccharothrix species.

  1. General Strain Theory as a Basis for the Design of School Interventions

    ERIC Educational Resources Information Center

    Moon, Byongook; Morash, Merry

    2013-01-01

    The research described in this article applies general strain theory to identify possible points of intervention for reducing delinquency of students in two middle schools. Data were collected from 296 youths, and separate negative binomial regression analyses were used to identify predictors of violent, property, and status delinquency. Emotional…

  2. A mixed community of actinomycetes produce multiple antibiotics for the fungus farming ant Acromyrmex octospinosus

    PubMed Central

    2010-01-01

    Background Attine ants live in an intensely studied tripartite mutualism with the fungus Leucoagaricus gongylophorus, which provides food to the ants, and with antibiotic-producing actinomycete bacteria. One hypothesis suggests that bacteria from the genus Pseudonocardia are the sole, co-evolved mutualists of attine ants and are transmitted vertically by the queens. A recent study identified a Pseudonocardia-produced antifungal, named dentigerumycin, associated with the lower attine Apterostigma dentigerum consistent with the idea that co-evolved Pseudonocardia make novel antibiotics. An alternative possibility is that attine ants sample actinomycete bacteria from the soil, selecting and maintaining those species that make useful antibiotics. Consistent with this idea, a Streptomyces species associated with the higher attine Acromyrmex octospinosus was recently shown to produce the well-known antifungal candicidin. Candicidin production is widespread in environmental isolates of Streptomyces, so this could either be an environmental contaminant or evidence of recruitment of useful actinomycetes from the environment. It should be noted that the two possibilities for actinomycete acquisition are not necessarily mutually exclusive. Results In order to test these possibilities we isolated bacteria from a geographically distinct population of A. octospinosus and identified a candicidin-producing Streptomyces species, which suggests that they are common mutualists of attine ants, most probably recruited from the environment. We also identified a Pseudonocardia species in the same ant colony that produces an unusual polyene antifungal, providing evidence for co-evolution of Pseudonocardia with A. octospinosus. Conclusions Our results show that a combination of co-evolution and environmental sampling results in the diversity of actinomycete symbionts and antibiotics associated with attine ants. PMID:20796277

  3. Microbispora sp. LGMB259 Endophytic Actinomycete Isolated from Vochysia divergens (Pantanal, Brazil) Producing β-Carbolines and Indoles with Biological Activity

    PubMed Central

    Savi, Daiani C.; Shaaban, Khaled A.; Vargas, Nathalia; Ponomareva, Larissa V.; Possiede, Yvelise M.; Thorson, Jon S.; Glienke, Chirlei; Rohr, Jürgen

    2014-01-01

    Endophytic actinomycetes encompass bacterial groups that are well known for the production of a diverse range of secondary metabolites. Vochysia divergens is a medicinal plant, common in the “Pantanal” region (Brazil) and was focus of many investigations, but never regarding its community of endophytic symbionts. During a screening program, an endophytic strain isolated from the V. divergens, was investigated for its potential to show biological activity. The strain was characterized as Microbispora sp. LGMB259 by spore morphology and molecular analyze using nucleotide sequence of the 16S rRNA gene. Strain LGMB259 was cultivated in R5A medium producing metabolites with significant antibacterial activity. The strain produced 4 chemically related β-carbolines, and 3 Indoles. Compound 1-Vinyl-β-carboline-3-carboxylic acid displayed potent activity against the Gram-positive bacterial strains Micrococcus luteus NRRL B-2618 and Kocuria rosea B-1106, and was highly active against two human cancer cell lines, namely the prostate cancer cell line PC3 and the non-small-cell lung carcinoma cell line A549, with IC50 values of 9.45 and 24.67 µM, respectively. 1-Vinyl-β-carboline-3-carboxylic acid also showed moderate activity against the yeast Saccharomyces cerevisiae ATCC204508, as well as the phytopathogenic fungiPhyllosticta citricarpa LGMB06 and Colletotrichum gloeosporioides FDC83. PMID:25385358

  4. Functional elucidation of hypothetical proteins for their indispensable roles towards drug designing targets from Helicobacter pylori strain HPAG1.

    PubMed

    Singh, Gagandeep; Singh, Vikram

    2017-03-03

    Helicobacter pylori is a flagellated and slow growing gram-negative bacterium that persistently infects about half of the entire world population. In present study, we examined the proteome of Helicobacter pylori strain HPAG1 for identification of key uncharacterized proteins towards their novel regulatory functions. The complete proteome of this strain consists of 1539 proteins, out of which 520 proteins are annotated as hypothetical. Based on the functional motifs in their primary sequences, we were able to classify 254 of these hypothetical proteins into 6 functional categories. Further, KEGG database was used to find the roles of these hypothetical proteins in several pathways and structural prediction was done by homology modelling methods. 33 of these hypothetical proteins were found to have strong association in various pathways including signalling and defence mechanisms. We noted that 27 of these proteins are specific to H. pylori and can be selected for drug designing targets, based on their virulence and regulatory role. We were able to successfully model the 3D structures of 3 of these proteins: YP_626977.1, YP_626786.1 and YP_628146.1. The stability of these proteins was also validated using molecular dynamics simulations and their possible role in the regulation of different pathways was explained. These novel annotations may contribute to the understanding of disease mechanism at molecular level and provide novel potential targets for designing new drugs against H. pylori strain HPAG1.

  5. Pseudonocardians A–C, New Diazaanthraquinone Derivatives from a Deap-Sea Actinomycete Pseudonocardia sp. SCSIO 01299

    PubMed Central

    Li, Sumei; Tian, Xinpeng; Niu, Siwen; Zhang, Wenjun; Chen, Yuchan; Zhang, Haibo; Yang, Xianwen; Zhang, Weimin; Li, Wenjun; Zhang, Si; Ju, Jianhua; Zhang, Changsheng

    2011-01-01

    Pseudonocardians A–C (2–4), three new diazaanthraquinone derivatives, along with a previously synthesized compound deoxynyboquinone (1), were produced by the strain SCSIO 01299, a marine actinomycete member of the genus Pseudonocardia, isolated from deep-sea sediment of the South China Sea. The structures of compounds 1–4 were determined by mass spectrometry and NMR experiments (1H, 13C, HSQC, and HMBC). The structure of compound 1, which was obtained for the first time from a natural source, was confirmed by X-ray analysis. Compounds 1–3 exhibited potent cytotoxic activities against three tumor cell lines of SF-268, MCF-7 and NCI-H460 with IC50 values between 0.01 and 0.21 μm, and also showed antibacterial activities on Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212 and Bacillus thuringensis SCSIO BT01, with MIC values of 1–4 μg mL−1. PMID:21892356

  6. Design and implementation of an x-ray strain measurement capability using a rotating anode machine

    SciTech Connect

    Roberts, J.A.; Rangaswamy, P.; Lujan, M. Jr.; Bourke, M.A.M.

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Residual stresses close to the surface can improve the reliability and lifetime of parts for technological applications. X-ray diffraction plays a significant role in gaining an exact knowledge of the stresses at the surface and their depth distribution. An x-ray capability at Los Alamos is key to developing and maintaining industrial collaborations in strain effects. To achieve this goal, the authors implemented a residual strain measuring station on the rotating anode x-ray instrument at the Lujan Center. This capability has been used to investigate residual strains in heat treated automotive components, machining effects on titanium alloys, resistance welded steel joints, titanium matrix fiber reinforced composites, ceramic matrix composites, thin films, and ceramic coatings. The overall objective is to combine both x-ray and neutron diffraction measurements with numerical models (e.g., finite element calculations).

  7. Rhodococcus kyotonensis sp. nov., a novel actinomycete isolated from soil.

    PubMed

    Li, Bing; Furihata, Keiko; Ding, Lin-Xian; Yokota, Akira

    2007-09-01

    A polyphasic study was undertaken to establish the taxonomic position of an isolate, strain DS472(T), from soil in Kyoto, Japan. Phylogenetic analysis, based on the 16S rRNA gene sequences, revealed that this strain constitutes a new subline within the genus Rhodococcus, with Rhodococcus yunnanensis YIM 70056(T) and Rhodococcus fascians DSM 20669(T) as its nearest phylogenetic neighbours (98.2 and 97.8 % sequence similarity, respectively). DNA-DNA hybridization experiments revealed 36 and 29 % relatedness between the isolate and its phylogenetic relatives, R. yunnanensis and R. fascians, respectively. Chemotaxonomic characteristics, including the major quinone MK-8(H(2)), predominant fatty acids C(16 : 0), C(18 : 1)omega9c and 10-methyl C(18 : 0), the presence of cell-wall chemotype IV and mycolic acids, were consistent with the properties of members of the genus Rhodococcus. The DNA G+C content was 64.5 mol%. On the basis of both phenotypic and genotypic evidence, strain DS472(T) represents a novel species of the genus Rhodococcus, for which the name Rhodococcus kyotonensis sp. nov. is proposed. The type strain is strain DS472(T) (=IAM 15415(T)=CCTCC AB206088(T)).

  8. Actinomadura xylanilytica sp. nov., an actinomycete isolated from soil.

    PubMed

    Zucchi, Tiago Domingues; Kim, Byung-Yong; Bonda, Avinash Naga Venkata; Goodfellow, Michael

    2013-02-01

    The taxonomic position of a soil isolate, strain BK147(T), was established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological characteristics consistent with its classification in the genus Actinomadura. It formed a distinct phyletic line in the phylogenetic tree based on 16S rRNA gene sequences of members of the genus Actinomadura and was most closely, albeit loosely, related to Actinomadura bangladeshensis DSM 45347(T), Actinomadura meyerae DSM 44715(T) and Actinomadura napierensis NRRL B-24319(T) but was readily distinguished from these strains using a range of phenotypic properties. Based on the combined genotypic and phenotypic data it is proposed that isolate BK147(T) ( = KACC 20919(T) = NCIMB 14771(T) = NRRL B-24852(T)) be classified as the type strain of a novel species of the genus Actinomadura, for which the name Actinomadura xylanilytica sp. nov. is proposed.

  9. Design guidelines for GaSb/InAs TFET exploiting strain and device size

    NASA Astrophysics Data System (ADS)

    Visciarelli, Michele; Gnani, Elena; Gnudi, Antonio; Reggiani, Susanna; Baccarani, Giorgio

    2017-03-01

    A simulation study exploring the possibility of performance improvements for GaSb/InAs nanowire TFETs under appropriate stress conditions is carried out. It is demonstrated that biaxial tensile strain induces a remarkable enhancement of the on-state current thanks to bandgap reduction; however, a degradation of the ambipolar behavior is observed as well. Some stress intensity values and device geometry configurations are investigated. The best simulated device can achieve an on/off current ratio of about 3 ×107 with ION ≈ 0.33 mA/ μ m at VDD = 0.3 V.

  10. Presence, molecular characteristics and geosmin producing ability of actinomycetes isolated from South Korean terrestrial and aquatic environments.

    PubMed

    Lee, Gyu-Cheol; Kim, Yun S; Kim, Min-Jeong; Oh, Sung-Ae; Choi, Ilhwan; Choi, Jaewon; Park, Jong-Geun; Chong, Chom-Kyu; Kim, Yong-Yeon; Lee, Kyeunghee; Lee, Chan Hee

    2011-01-01

    The unpleasant odor of drinking water is one of the major problems in many water utilities in the world. Actinomycetes have long been associated with odorous compounds. Considering the paucity of research on Actinomycetes producing odorous compounds in South Korea, presence of Actinomycetes, their molecular characteristics and ability to produce odorous compounds were investigated in this study. Findings confirmed the presence of Actinomycetes in surface soil, sediment, and water samples from four sites: two artificial lakes [Paldang and Cheongpyeong (CP)], and two streams [Gyeongan (GA) and Yangpyeong]. Surface soil and sediment from CP area had the greatest concentration of Actinomycetes (8.2 x 10(7) and 6.8 x 10(6) colony forming units (CFUs)/gram, dry weight, respectively). When water samples are considered, samples from GA had the highest concentration (1.9 x 10(2) CFU/mL). 16S rRNA sequencing and molecular phylogenetic analysis showed that Streptomyces was the dominant genus (64.1%). In addition, the isolated Actinomycetes synthesized 5.4 ng/L geosmin as demonstrated by thermal desorption unit-gas chromatograph/mass spectrometry analysis.

  11. Unique actinomycetes from marine caves and coral reef sediments provide novel PKS and NRPS biosynthetic gene clusters.

    PubMed

    Hodges, Tyler W; Slattery, Marc; Olson, Julie B

    2012-06-01

    In the ever-expanding search for novel bioactive molecules and enzymes, marine actinomycetes have proven to be a productive source. While open reef sediment and sponge-associated actinomycetes have been extensively examined, their marine cave counterparts remain unevaluated. Anchialine cave systems in the Bahamas offered an ideal setting to evaluate the occurrence and variation within sediment-associated actinomycete communities. While in close geographical proximity to open reef environments, these systems provide a specialized environmental niche devoid of light and direct exposure to nutrient input. In the present study, selective isolation techniques and molecular methods were used to test the hypothesis that variable distribution of actinomycetes and secondary metabolite gene clusters occur between open reef and marine cave systems. The results indicated that differences exist within the culturable sediment-associated actinomycete communities between marine caves and open reef systems, with members of the genus Streptomyces dominating cultures from open reef sediments and a more diverse suite of actinomycetes isolated from marine cave sediment samples. Within the cave isolates, members of the proposed genus Solwaraspora were the most represented. Based on PKS- and NRPS-gene-targeted PCR amplification and sequencing, geographic variation in the occurrence of these biosynthetic pathways was also observed. These findings indicate that marine cave systems are a lucrative source in the search for novel secondary metabolite producers with biotechnological applications and that environmental and geographic factors likely affect the occurrence of these biosynthetic pathways.

  12. Strain Design of Ashbya gossypii for Single-Cell Oil Production

    PubMed Central

    Ledesma-Amaro, Rodrigo; Santos, María A.; Jiménez, Alberto

    2014-01-01

    Single-cell oil (SCO) represents a sustainable alternative for the oil industry. Accordingly, the identification of microorganisms with either higher lipidogenic ability or novel capacities for the transformation of raw materials constitutes a major challenge for the field of oil biotechnology. With this in mind, here, we were prompted to address the lipidogenic profile of the filamentous hemiascomycete Ashbya gossypii, which is currently used for the microbial production of vitamins. We found that A. gossypii mostly accumulates unsaturated fatty acids (FAs), with more than 50% of the total FA content corresponding to oleic acid. In addition, we engineered A. gossypii strains both lacking the beta-oxidation pathway and also providing ATP-citrate lyase (ACL) activity to block the degradation of FA and to increase the cytosolic acetyl-coenzyme A (CoA) content, respectively. The lipidogenic profile of the newly developed strains demonstrates that the mere elimination of the beta-oxidation pathway in A. gossypii triggers a significant increase in lipid accumulation that can reach 70% of cell dry weight. The use of A. gossypii as a novel and robust tool for the production of added-value oils is further discussed. PMID:24317081

  13. Pseudonocardia nantongensis sp. nov., a novel endophytic actinomycete isolated from the coastal halophyte Tamarix chinensis Lour.

    PubMed

    Xing, Ke; Qin, Sheng; Bian, Guang-Kai; Zhang, Yue-Ji; Zhang, Wen-Di; Dai, Chuan-Chao; Liu, Chang-Hong; Li, Wen-Jun; Jiang, Ji-Hong

    2012-11-01

    A novel isolate, designated strain KLBMP 1282(T) was isolated from the surface-sterilized leaves of a coastal halophyte Tamarix chinensis Lour., collected from Nantong, Jiangsu Province, east of China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that this strain belongs to the genus Pseudonocardia, being most closely related to Pseudonocardia kongjuensis LM 157(T) (98.33 %), Pseudonocardia autotrophica IMSNU 20050(T) (97.77 %), Pseudonocardia endophytica YIM 56035(T) (97.63 %), Pseudonocardia ammonioxydans H9 (T) (97.62 %) and Pseudonocardia compacta IMSNU 20111(T) (97.56 %); similarity to other type strains of the genus Pseudonocardia was <97.5 %. Chemotaxonomic data confirmed the affiliation of strain KLBMP 1282(T) to the genus Pseudonocardia. Strain KLBMP 1282(T) contained MK-8(H(4)) as the predominant ubiquinone and iso-C(16:0) as the major fatty acid. The polar lipids detected in strain KLBMP 1282(T) were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, one unknown phospholipid and four unknown glycolipids. The DNA G + C content of strain KLBMP 1282(T) was 73.1 mol %. The results of DNA-DNA hybridizations and the phylogenetic analysis, together with the phenotypic and biochemical tests, allowed the differentiation of strain KLBMP 1282(T) from strains of other recognized Pseudonocardia species. Therefore, strain KLBMP 1282(T) represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia nantongensis sp. nov. is proposed. The type strain is KLBMP 1282(T) (=KCTC 29053(T) = NBRC 108677(T)).

  14. Draft Genome Sequence of Frankia sp. Strain BMG5.12, a Nitrogen-Fixing Actinobacterium Isolated from Tunisian Soils

    PubMed Central

    Nouioui, Imen; Beauchemin, Nicholas; Cantor, Michael N.; Chen, Amy; Detter, J. Chris; Furnholm, Teal; Ghodhbane-Gtari, Faten; Goodwin, Lynne; Gtari, Maher; Han, Cliff; Han, James; Huntemann, Marcel; Hua, Susan Xinyu; Ivanova, Natalia; Kyrpides, Nikos; Markowitz, Victor; Mavrommatis, Kostas; Mikhailova, Natalia; Nordberg, Henrik P.; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Sen, Arnab; Sur, Saubashya; Szeto, Ernest; Thakur, Subarna; Wall, Luis; Wei, Chia-Lin; Woyke, Tanja

    2013-01-01

    Members of the actinomycete genus Frankia form a nitrogen-fixing symbiosis with 8 different families of actinorhizal plants. We report a draft genome sequence for Frankia sp. strain BMG5.12, a nitrogen-fixing actinobacterium isolated from Tunisian soils with the ability to infect Elaeagnus angustifolia and Myrica gale. PMID:23846272

  15. Draft Genome Sequence of Frankia sp. Strain BMG5.12, a Nitrogen-Fixing Actinobacterium Isolated from Tunisian Soils.

    PubMed

    Nouioui, Imen; Beauchemin, Nicholas; Cantor, Michael N; Chen, Amy; Detter, J Chris; Furnholm, Teal; Ghodhbane-Gtari, Faten; Goodwin, Lynne; Gtari, Maher; Han, Cliff; Han, James; Huntemann, Marcel; Hua, Susan Xinyu; Ivanova, Natalia; Kyrpides, Nikos; Markowitz, Victor; Mavrommatis, Kostas; Mikhailova, Natalia; Nordberg, Henrik P; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Sen, Arnab; Sur, Saubashya; Szeto, Ernest; Thakur, Subarna; Wall, Luis; Wei, Chia-Lin; Woyke, Tanja; Tisa, Louis S

    2013-07-11

    Members of the actinomycete genus Frankia form a nitrogen-fixing symbiosis with 8 different families of actinorhizal plants. We report a draft genome sequence for Frankia sp. strain BMG5.12, a nitrogen-fixing actinobacterium isolated from Tunisian soils with the ability to infect Elaeagnus angustifolia and Myrica gale.

  16. Comparative genome-scale metabolic modeling of actinomycetes: the topology of essential core metabolism.

    PubMed

    Alam, Mohammad Tauqeer; Medema, Marnix H; Takano, Eriko; Breitling, Rainer

    2011-07-21

    Actinomycetes are highly important bacteria. On one hand, some of them cause severe human and plant diseases, on the other hand, many species are known for their ability to produce antibiotics. Here we report the results of a comparative analysis of genome-scale metabolic models of 37 species of actinomycetes. Based on in silico knockouts we generated topological and genomic maps for each organism. Combining the collection of genome-wide models, we constructed a global enzyme association network to identify both a conserved "core network" and an "essential core network" of the entire group. As has been reported for low-degree metabolites in several organisms, low-degree enzymes (in linear pathways) turn out to be generally more essential than high-degree enzymes (in metabolic hubs).

  17. Volatile terpenes from actinomycetes: a biosynthetic study correlating chemical analyses to genome data.

    PubMed

    Rabe, Patrick; Citron, Christian A; Dickschat, Jeroen S

    2013-11-25

    The volatile terpenes of 24 actinomycetes whose genomes have been sequenced (or are currently being sequenced) were collected by use of a closed-loop stripping apparatus and identified by GC/MS. The analytical data were compared against a phylogenetic analysis of all 192 currently available sequences of bacterial terpene cyclases (excluding geosmin and 2-methylisoborneol synthases). In addition to the several groups of terpenes with known biosynthetic origin, selinadienes were identified as a large group of biosynthetically related sesquiterpenes that are produced by several streptomycetes. The detection of a large number of previously unrecognised side products of known terpene cyclases proved to be particularly important for an in depth understanding of biosynthetic pathways to known terpenes in actinomycetes. Interpretation of the chemical analytical data in the context of the phylogenetic tree of bacterial terpene cyclases pointed to the function of three new enzymes: (E)-β-caryophyllene synthase, selina-3,7(11)-diene synthase and aristolochene synthase.

  18. Antibacterial Activities of Actinomycete Isolates Collected from Soils of Rajshahi, Bangladesh

    PubMed Central

    Rahman, Md. Ajijur; Islam, Mohammad Zahidul; Islam, Md. Anwar Ul

    2011-01-01

    This study was performed to isolate actinomycete colonies having antibacterial activity from soil samples collected from different places around Rajshahi, Bangladesh. Thirty actinomycete colonies were isolated in pure culture from five soil samples using Starch-casein-nitrate-agar medium. The isolates were grouped in five color series based on their aerial mycelia color and screened for their antibacterial activity against a range of test bacteria. Sixteen isolates (53.3%) were found to have moderate to high activity against four gram-positive and four gram-negative bacteria. Since many isolates showed inhibitory activity against indicator bacteria, it is suggestive that Bangladeshi soil could be an interesting source to explore for antibacterial secondary metabolites. PMID:21904683

  19. Targeted search for actinomycetes from near-shore and deep-sea marine sediments

    PubMed Central

    Prieto-Davó, Alejandra; Villarreal-Gómez, Luis Jesús; Forschner-Dancause, Stephanie; Bull, Alan T.; Stach, James E. M.; Smith, David C.; Rowley, Dave C.; Jensen, Paul R.

    2013-01-01

    Sediment samples collected off the coast of San Diego were analyzed for actinomycete diversity using culture independent techniques. Eight new operational taxonomic units (OTUs) in the Streptomycetaceae were identified as well as new diversity within previously cultured marine OTUs. Sequences belonging to the marine actinomycete genus Salinispora were also detected, despite the fact that this genus has only been reported from more tropical environments. Independent analyses of marine sediments from the Canary Basin (3814 m) and the South Pacific Gyre (5126 and 5699 m) also revealed Salinispora sequences providing further support for the occurrence of this genus in deep-sea sediments. Efforts to culture Salinispora spp. from these samples have yet to be successful. This is the first report of Salinispora spp. from marine sediments >1100m and suggests that the distribution of this genus is broader than previously believed. PMID:23360553

  20. Comparative finite element analysis of the stress-strain states in three different bonded solid oxide fuel cell seal designs

    NASA Astrophysics Data System (ADS)

    Weil, K. S.; Koeppel, B. J.

    One of the critical issues in designing and fabricating a high performance planar solid oxide fuel cell (pSOFC) stack is the development of the appropriate materials and techniques for hermetically sealing the metal and ceramic components. A second critical issue is ensuring that the brittle ceramic cell constituents, i.e. the electrodes and electrolyte, exhibit high mechanical reliability by mitigating potential sources of thermal-mechanically induced stresses that can lead to fracture during operation and/or shutdown. A foil-based sealing approach is currently being developed that appears to offer good hermeticity and mechanical integrity, while minimizing the generation of high stresses in either of the joint's substrate materials. Based on the concept's viability, demonstrated in prior experimental work, numerical analyses were conducted to evaluate the behavior and benefits of the seal in a configuration prototypic of current pSOFC stack designs. This paper presents recent results from finite element (FE) simulations of a planar cell using the foil-based seal, along with companion analyses of the more conventionally employed glass-ceramic and brazed joints. The stresses and deformations of the components were evaluated at isothermal operating and shutdown temperatures. The results indicate that the foil seal is able to accommodate a significant degree of thermal mismatch strain between the metallic support structure and the ceramic cell via elastic deformations of the foil and plasticity in the foil-to-cell braze layer. Consequently the cell stresses in this type of seal are predicted to be much lower than those in the glass-ceramic and brazed designs, which is expected to lead to improved stack reliability. This ability to accommodate large thermal strain mismatches allows the design requirement of thermal expansion matching between ceramic and metal stack components to be relaxed and expands the list of candidate materials that can be considered for the

  1. Molecular characterization of nocardioform actinomycetes in activated sludge by 16S rRNA analysis.

    PubMed

    Schuppler, M; Mertens, F; Schön, G; Göbel, U B

    1995-02-01

    The analysis of complex microbiota present in activated sludge is important for the understanding and possible control of severe separation problems in sewage treatment such as sludge bulking or sludge foaming. Previous studies have shown that nocardioform actinomycetes are responsible for these conditions, which not only affect the efficiency of sewage treatment but also represent a threat to public health due to spread of pathogens. However, isolation and identification of these filamentous, nocardioform actinomycetes is hampered by their fastidious nature. Most species are still uncultivable and their taxonomy is unresolved. To study the ecology of these micro-organisms at the molecular level, we have established a clone library of 16S rRNA gene fragments amplified from bulk sludge DNA. A rough indication of the predominant flora in the sludge was given by sequencing randomly chosen clones, which revealed a great diversity of bacteria from different taxa. Colony hybridization with oligonucleotide probe MNP1 detected 27 clones with 16S rDNA inserts from nocardioform actinomycetes and mycobacteria. The sequence data from these clones together with those from randomly chosen clones were used for comparative 16S rRNA analysis and construction of dendrograms. All sequences differed from those of previously sequenced species in the databases. Phenotypic characterization of isolates of nocardioform actinomycetes and mycobacteria cultivated in parallel from the same activated-sludge sample revealed a large discrepancy between the two approaches. Only one 16S rDNA sequence of a cultured isolate was represented in the clone library, indicating that culture conditions could select species which represent only a small fraction of the organisms in the activated sludge.

  2. Actinomycete integrative and conjugative pMEA-like elements of Amycolatopsis and Saccharopolyspora decoded.

    PubMed

    te Poele, Evelien M; Samborskyy, Markiyan; Oliynyk, Markiyan; Leadlay, Peter F; Bolhuis, Henk; Dijkhuizen, Lubbert

    2008-05-01

    Actinomycete integrative and conjugative elements (AICEs) are present in diverse genera of the actinomycetes, the most important bacterial producers of bioactive secondary metabolites. Comparison of pMEA100 of Amycolatopsis mediterranei, pMEA300 of Amycolatopsis methanolica and pSE211 of Saccharopolyspora erythraea, and other AICEs, revealed a highly conserved structural organisation, consisting of four functional modules (replication, excision/integration, regulation, and conjugative transfer). Features conserved in all elements, or specific for a single element, are discussed and analysed. This study also revealed two novel putative AICEs (named pSE222 and pSE102) in the Sac. erythraea genome, related to the previously described pSE211 and pSE101 elements. Interestingly, pSE102 encodes a putative aminoglycoside phosphotransferase which may confer antibiotic resistance to the host. Furthermore, two of the six pSAM2-like insertions in the Streptomyces coelicolor genome described by Bentley et al. [Bentley, S.D., Chater, K.F., Cerdeno-Tarraga, A.M., et al., 2002. Complete genome sequence of the model actinomycete Streptomyces coelicolor A3(2). Nature 417, 141-147] could be functional AICEs. Homologues of various AICE proteins were found in other actinomycetes, in Frankia species and in the obligate marine genus Salinispora and may be part of novel AICEs as well. The data presented provide a better understanding of the origin and evolution of these elements, and their functional properties. Several AICEs are able to mobilise chromosomal markers, suggesting that they play an important role in horizontal gene transfer and spread of antibiotic resistance, but also in evolution of genome plasticity.

  3. Mycobacterium and Aerobic Actinomycete Culture: Are Two Medium Types and Extended Incubation Times Necessary?

    PubMed

    Simner, Patricia J; Doerr, Kelly A; Steinmetz, Lory K; Wengenack, Nancy L

    2016-04-01

    Mycobacterial cultures are historically performed using a liquid medium and a solid agar medium with an incubation period of up to 60 days. We performed a retrospective analysis of 21,494 mycobacterial and aerobic actinomycetes cultures performed over 10 months to determine whether two medium types remain necessary and to investigate whether culture incubation length can be shortened. Specimens were cultured using Bactec MGIT liquid medium and Middlebrook 7H11/S7H11 solid medium with incubation periods of 42 and 60 days, respectively. Time-to-positivity and the identity of isolates recovered from each medium were evaluated. A total of 1,205/21,494 cultures (6%) were positive on at least one medium. Of the 1,353 isolates recovered, 1,110 (82%) were nontuberculous mycobacteria, 145 (11%) were aerobic actinomycetes, and 98 (7%) wereMycobacterium tuberculosiscomplex. Assessing medium types, 1,121 isolates were recovered from solid medium cultures, 922 isolates were recovered from liquid medium cultures, and 690 isolates were recovered on both media. Liquid cultures were positive an average of 10 days before solid cultures when the two medium types were positive (P< 0.0001). Isolates detected on solid medium after 6 weeks of incubation included 65 (5%) nontuberculous mycobacteria, 4 (0.3%) aerobic actinomycetes, and 2 (0.2%) isolates from theM. tuberculosiscomplex. Medical chart review suggested that most of these later-growing isolates were insignificant, as the diagnosis was already known, or they were considered colonizers/contaminants. This study reaffirms the need for both liquid medium and solid medium for mycobacterial and aerobic actinomycetes culture and demonstrates that solid medium incubation times may be reduced to 6 weeks without significantly impacting sensitivity.

  4. Actinomycetes: a repertory of green catalysts with a potential revenue resource.

    PubMed

    Prakash, Divya; Nawani, Neelu; Prakash, Mansi; Bodas, Manish; Mandal, Abul; Khetmalas, Madhukar; Kapadnis, Balasaheb

    2013-01-01

    Biocatalysis, one of the oldest technologies, is becoming a favorable alternative to chemical processes and a vital part of green technology. It is an important revenue generating industry due to a global market projected at $7 billion in 2013 with a growth of 6.7% for enzymes alone. Some microbes are important sources of enzymes and are preferred over sources of plant and animal origin. As a result, more than 50% of the industrial enzymes are obtained from bacteria. The constant search for novel enzymes with robust characteristics has led to improvisations in the industrial processes, which is the key for profit growth. Actinomycetes constitute a significant component of the microbial population in most soils and can produce extracellular enzymes which can decompose various materials. Their enzymes are more attractive than enzymes from other sources because of their high stability and unusual substrate specificity. Actinomycetes found in extreme habitats produce novel enzymes with huge commercial potential. This review attempts to highlight the global importance of enzymes and extends to signify actinomycetes as promising harbingers of green technology.

  5. Macroamphiphilic Components of Thermophilic Actinomycetes: Identification of Lipoteichoic Acid in Thermobifida fusca▿ †

    PubMed Central

    Rahman, Obaidur; Pfitzenmaier, Markus; Pester, Oxana; Morath, Siegfried; Cummings, Stephen P.; Hartung, Thomas; Sutcliffe, Iain C.

    2009-01-01

    The cell envelopes of gram-positive bacteria contain structurally diverse membrane-anchored macroamphiphiles (lipoteichoic acids and lipoglycans) whose functions are poorly understood. Since regulation of membrane composition is an important feature of adaptation to life at higher temperatures, we have examined the nature of the macroamphiphiles present in the thermophilic actinomycetes Thermobifida fusca and Rubrobacter xylanophilus. Following hot-phenol-water extraction and purification by hydrophobic interaction chromatography, Western blotting with a monoclonal antibody against lipoteichoic acid strongly suggested the presence of a polyglycerophosphate lipoteichoic acid in T. fusca. This structure was confirmed by chemical and nuclear magnetic resonance analyses, which confirmed that the lipoteichoic acid is substituted with β-glucosyl residues, in common with the teichoic acid of this organism. In contrast, several extraction methods failed to recover significant macroamphiphilic carbohydrate- or phosphate-containing material from R. xylanophilus, suggesting that this actinomycete most likely lacks a membrane-anchored macroamphiphile. The finding of a polyglycerophosphate lipoteichoic acid in T. fusca suggests that lipoteichoic acids may be more widely present in the cell envelopes of actinomycetes than was previously assumed. However, the apparent absence of macroamphiphiles in the cell envelope of R. xylanophilus is highly unusual and suggests that macroamphiphiles may not always be essential for cell envelope homeostasis in gram-positive bacteria. PMID:18931132

  6. Occupational allergic respiratory diseases in garbage workers: relevance of molds and actinomycetes.

    PubMed

    Hagemeyer, O; Bünger, J; van Kampen, V; Raulf-Heimsoth, M; Drath, C; Merget, R; Brüning, Th; Broding, H C

    2013-01-01

    Exposures to molds and bacteria (especially actinomycetes) at workplaces are common in garbage workers, but allergic respiratory diseases due to these microorganisms have been described rarely. The aim of our study was a detailed analysis of mold or bacteria-associated occupational respiratory diseases in garbage workers. From 2002 to 2011 four cases of occupational respiratory diseases related to garbage handling were identified in our institute (IPA). Hypersensitivity pneumonitis (HP) was diagnosed in three subjects (cases 1-3, one smoker, two non-smokers), occupational asthma (OA) was diagnosed in one subject (case 4, smoker), but could not be excluded completely in case 2. Cases 1 and 2 worked in composting sites, while cases 3 and 4 worked in packaging recycling plants. Exposure periods were 2-4 years. Molds and actinomycetes were identified as allergens in all cases. Specific IgE antibodies to Aspergillus fumigatus were detected exclusively in case 4. Diagnoses of HP were essentially based on symptoms and the detection of specific IgG serum antibodies to molds and actinomycetes. OA was confirmed by bronchial provocation test with Aspergillus fumigatus in case 4. In conclusion, occupational HP and OA due to molds occur rarely in garbage workers. Technical prevention measures are insufficient and the diagnosis of HP is often inconclusive. Therefore, it is recommended to implement the full repertoire of diagnostic tools including bronchoalveolar lavage and high resolution computed tomography in the baseline examination.

  7. Novel actinomycete and a cyanide-degrading pseudomonad isolated from industrial sludge

    SciTech Connect

    White, J.M.

    1987-01-01

    A novel actinomycete was the predominant filamentous microorganism in bulking activated sludge in a bench-scale reactor treating coke plant wastewater. The bacterium was isolated and identified as an actinomycete that is biochemically and morphologically similar to Amycolatopsis orientalis; however, a lack of DNA homology excludes true relatedness. At present, the isolate (NRRL B 16216) cannot be assigned to the recognized taxa of actinomycetes. Cyanide-degrading microorganisms were selected in chemostats maintained at a low dilution rate for several weeks. Cyanide alone or cyanide plus phenol were fully degraded when equilibrium was achieved, and increasing concentrations of cyanide were degraded until inhibition of cell division resulted in cell washout. An isolated non-fluorescent pseudomonad could be adapted to degrade high concentrations of cyanide and to utilize cyanide-nitrogen when phenol or lactate was the carbon source. Although one-carbon compounds such as methanol and methylamine were growth substrates, cyanide was not utilized as a carbon source. In the absence of cyanide, adaptation was gradually lost. Oxygen consumption of adapted cells was stimulated in the presence of cyanide whereas that of unadapted cells was depressed. Cyanide was degraded by growing or resting cells and by cell-free extracts. Cyanide degrading activity of cell-free extracts, lost upon dialysis, was fully restored with NAD(P)H.

  8. Actinomycetes: A Repertory of Green Catalysts with a Potential Revenue Resource

    PubMed Central

    Prakash, Divya; Nawani, Neelu; Prakash, Mansi; Bodas, Manish; Mandal, Abul; Khetmalas, Madhukar; Kapadnis, Balasaheb

    2013-01-01

    Biocatalysis, one of the oldest technologies, is becoming a favorable alternative to chemical processes and a vital part of green technology. It is an important revenue generating industry due to a global market projected at $7 billion in 2013 with a growth of 6.7% for enzymes alone. Some microbes are important sources of enzymes and are preferred over sources of plant and animal origin. As a result, more than 50% of the industrial enzymes are obtained from bacteria. The constant search for novel enzymes with robust characteristics has led to improvisations in the industrial processes, which is the key for profit growth. Actinomycetes constitute a significant component of the microbial population in most soils and can produce extracellular enzymes which can decompose various materials. Their enzymes are more attractive than enzymes from other sources because of their high stability and unusual substrate specificity. Actinomycetes found in extreme habitats produce novel enzymes with huge commercial potential. This review attempts to highlight the global importance of enzymes and extends to signify actinomycetes as promising harbingers of green technology. PMID:23691495

  9. Numerical and chemical classification of Streptosporangium and some related actinomycetes.

    PubMed

    Whitham, T S; Athalye, M; Minnikin, D E; Goodfellow, M

    One hundred and seventeen streptosporangia from soil were compared with marker strains of the family Streptosporangiaceae for many phenotypic properties. The data were examined using the Jaccard, pattern and simple matching coefficients with clustering achieved using average, complete and single linkage algorithms. Particular confidence was placed in the product of the pattern, average linkage analysis given the sharp definition of aggregate groups and clusters and a combination of low test error and high cophenetic correlation values. The test strains were assigned to five aggregate groups that were equated with the genera Streptosporangium (group A), Microbispora (group B), Planobispora and Planomonospora (Group C), Kutzneria (neé Streptosporangium viridogriseum (group D), and Microtetraspora (group E). The streptosporangia, both isolates and marker strains, were assigned to 5 major, 7 minor and 18 single membered clusters. Representative streptosporangia examined for chemical markers were characterised by the presence of meso-diaminopimelic acid in whole-organism hydrolysates, complex mixtures of straight- and branched chain fatty acids, di- and tetrahydrogenated menaquinones as predominant isoprenologues, and complex polar lipid patterns containing diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and uncharacterised components. The chemical and numerical data support the taxonomic integrity of the validly described species of Streptosporangium and suggest that the genus is markedly underspeciated.

  10. Taxonomic study and partial characterization of antimicrobial compounds from a moderately halophilic strain of the genus Actinoalloteichus

    PubMed Central

    Boudjelal, Farida; Zitouni, Abdelghani; Mathieu, Florence; Lebrihi, Ahmed; Sabaou, Nasserdine

    2011-01-01

    A moderately halophilic actinomycete strain designated AH97 was isolated from a saline Saharan soil, and selected for its antimicrobial activities against bacteria and fungi. The AH97 strain was identified by morphological, chemotaxonomic and phylogenetic analyses to the genus Actinoalloteichus. Analysis of the 16S rDNA sequence of strain AH97 showed a similarity level ranging between 95.8% and 98.4% within Actinoalloteichus species, with A. hymeniacidonis the most closely related. The comparison of the physiological characteristics of AH97 with those of known species of Actinoalloteichus showed significant differences. Strain AH97 showed an antibacterial and antifungal activity against broad spectrum of microorganisms known to be human and plant pathogens. The bioactive compounds were extracted from the filtrate culture with n-butanol and purified using thin layer chromatography and high pressure liquid chromatography procedures. Two active products were isolated, one hydrophilic fraction (F1) and another hydrophobic (F2). Ultraviolet-visible, infrared, mass and 1H and 13C nuclear magnetic resonance spectroscopy studies suggested that these molecules were the dioctyl phthalate (F2) and an aminoglycosidic compound (F1). PMID:24031699

  11. Taxonomic study and partial characterization of antimicrobial compounds from a moderately halophilic strain of the genus Actinoalloteichus.

    PubMed

    Boudjelal, Farida; Zitouni, Abdelghani; Mathieu, Florence; Lebrihi, Ahmed; Sabaou, Nasserdine

    2011-07-01

    A moderately halophilic actinomycete strain designated AH97 was isolated from a saline Saharan soil, and selected for its antimicrobial activities against bacteria and fungi. The AH97 strain was identified by morphological, chemotaxonomic and phylogenetic analyses to the genus Actinoalloteichus. Analysis of the 16S rDNA sequence of strain AH97 showed a similarity level ranging between 95.8% and 98.4% within Actinoalloteichus species, with A. hymeniacidonis the most closely related. The comparison of the physiological characteristics of AH97 with those of known species of Actinoalloteichus showed significant differences. Strain AH97 showed an antibacterial and antifungal activity against broad spectrum of microorganisms known to be human and plant pathogens. The bioactive compounds were extracted from the filtrate culture with n-butanol and purified using thin layer chromatography and high pressure liquid chromatography procedures. Two active products were isolated, one hydrophilic fraction (F1) and another hydrophobic (F2). Ultraviolet-visible, infrared, mass and (1)H and (13)C nuclear magnetic resonance spectroscopy studies suggested that these molecules were the dioctyl phthalate (F2) and an aminoglycosidic compound (F1).

  12. The variable hydroxamic acid siderophore metabolome of the marine actinomycete Salinispora tropica CNB-440.

    PubMed

    Ejje, Najwa; Soe, Cho Zin; Gu, Jiesi; Codd, Rachel

    2013-11-01

    The recently sequenced genome of the marine actinomycete Salinispora tropica CNB-440 revealed a high frequency of gene clusters which code for the biosynthesis of known and novel secondary metabolites. Of these metabolites, bioinformatics analysis predicted that S. tropica CNB-440 could potentially biosynthesize, as high affinity Fe(iii) ligands, siderophores from the hydroxamic acid desferrioxamine class (sid1 gene cluster) and the phenolate-thia(oxa)zoli(di)ne class (sid2 and sid4 gene clusters). In this work, we have used Ni(ii)-based immobilized metal ion affinity chromatography (IMAC) to pre-fractionate the hydroxamic acid siderophore metabolome of S. tropica CNB-440 from the secondary metabolome, to reveal low abundance siderophores. LC-MS measurements and electronic absorption spectra from purified extracts incubated with exogenous Fe(iii) revealed eight siderophores from the desferrioxamine class (DFOA2, DFOA1a, DFOA1b, DFOB, DFON, DFOD2, DFOE, DFOD1), which included two constitutional isomers (DFOA1a, DFOA1b), and one new siderophore (DFON), the latter which would require assembly from a combination of 1,5-diaminopentane and 1,6-diaminohexane as diamine substrates. Three additional species (m/zobs 496.14, 792.34 and 804.34) with electronic absorption spectra characteristic of complexes formed between Fe(iii) and hydroxamic acid-type siderophores were evident under some conditions. The signal at m/zobs 792.34 eluted in the hydrophobic region of the reverse-phase LC and correlated with a DFOD1 analogue with a C-terminal branched chain fatty acid ([M + K(+)](+)m/zcalc 792.35), which has been previously identified from marine sediment dwelling Micrococcus luteus KLE1011. The S. tropica CNB-440 hydroxamic acid siderophore metabolome was modulated by culture conditions (pH 7, 22 °C; pH 7, 28 °C; pH 9, 28 °C) designed to simulate the variable marine environment. An increase in temperature at constant pH value showed increased levels of DFOA2 and DFOA1, and

  13. Quantification of Gordona amarae Strains in Foaming Activated Sludge and Anaerobic Digester Systems with Oligonucleotide Hybridization Probes

    PubMed Central

    de los Reyes, M. Fiorella; de los Reyes, Francis L.; Hernandez, Mark; Raskin, Lutgarde

    1998-01-01

    Previous studies have shown the predominance of mycolic acid-containing filamentous actinomycetes (mycolata) in foam layers in activated sludge systems. Gordona (formerly Nocardia) amarae often is considered the major representative of this group in activated sludge foam. In this study, small-subunit rRNA genes of four G. amarae strains were sequenced, and the resulting sequences were compared to the sequence of G. amarae type strain SE-6. Comparative sequence analysis showed that the five strains used represent two lines of evolutionary descent; group 1 consists of strains NM23 and ASAC1, and group 2 contains strains SE-6, SE-102, and ASF3. The following three oligonucleotide probes were designed: a species-specific probe for G. amarae, a probe specific for group 1, and a probe targeting group 2. The probes were characterized by dissociation temperature and specificity studies, and the species-specific probe was evaluated for use in fluorescent in situ hybridizations. By using the group-specific probes, it was possible to place additional G. amarae isolates in their respective groups. The probes were used along with previously designed probes in membrane hybridizations to determine the abundance of G. amarae, group 1, group 2, bacterial, mycolata, and Gordona rRNAs in samples obtained from foaming activated sludge systems in California, Illinois, and Wisconsin. The target groups were present in significantly greater concentrations in activated sludge foam than in mixed liquor and persisted in anaerobic digesters. Hybridization results indicated that the presence of certain G. amarae strains may be regional or treatment plant specific and that previously uncharacterized G. amarae strains may be present in some systems. PMID:9647822

  14. Dereplication for biotechnology screening: PyMS analysis and PCR-RFLP-SSCP (PRS) profiling of 16S rRNA genes of marine and terrestrial actinomycetes.

    PubMed

    Brandão, Pedro F B; Torimura, Masaki; Kurane, Ryuichiro; Bull, Alan T

    2002-01-01

    The search for exploitable biology is a major task for biotechnology-based industries. In this context, discrimination between previously tested or recovered micro-organisms (dereplication) is imperative, in order to reduce screening costs by sorting large collections of isolates, which are then subjected to further detailed evaluation. Pyrolysis mass spectrometry (PyMS) is a whole-cell fingerprinting technique that enables the rapid and reproducible sorting of micro-organisms, uses small samples and has the advantage of being fully automated. In this study, we compare chemometric fingerprinting with a ribotyping fingerprinting method, in order to investigate the extent to which pyrogroups formed by PyMS analysis relate to genetic diversity, using polymerase chain reaction-restriction fragment length polymorphism-single-strand conformational polymorphism (PRS). A mixture of environmental strains of mycolic acid containing actinomycetes was used to mimic the selection of colonies from primary isolation plates. The congruence found between the clusters defined by the chemometric and molecular fingerprinting techniques was very high and demonstrated the effectiveness of PyMS as a rapid sorting and dereplicating procedure for putatively novel strains, criteria that are critical for biotechnological screens. Moreover, PyMS analysis revealed significant variation within pyrogroups that contained strains with the same genotypic (PRS) characteristics, thus emphasising its discriminatory capacity at the infraspecies level.

  15. Evaluating a prototype device designed to alleviate night vision goggle induced neck strain among military personnel.

    PubMed

    Dibblee, Jenna; Worthy, Portia; Farrell, Philip; Hetzler, Markus; Reid, Susan; Stevenson, Joan; Fischer, Steven

    2015-01-01

    The purpose of this study was verify the design of a novel Helmet System Support Device (HSSD) that can be used by military aircrew to help intervene on and reduce the high prevalence of neck trouble. Twelve healthy participants repeated simulated helicopter aircrew tasks on 3 separate days. On each day they wore a different helmet configuration, where measures of performance, perceived demand/preference and muscular demand were recorded. The results showed that vigilance tasks were performed over 10% faster with the HSSD configuration compared to wearing the normal helmet configuration. Participants were able to maintain static (endurance) postures for 28% longer, and use of the HSSD helped to prevent neck muscle fatigue in the most demanding task. The results of this design verification study indicate that the HSSD may be a realistic, feasible near-term solution to intervene on the high prevalence of neck trouble among rotary-wing aircrew. Practitioner Summary: This paper verifies the effectiveness of the Helmet System Support Device (HSSD) as an on-body personal protective device to help control exposures associated with aircrew neck trouble. The HSSD reduced perceived demand, reduced cumulative muscle activity in select muscles and provided improved fatigue resistance, meeting its desired design objectives.

  16. The biodegradation of layered silicates under the influence of cyanobacterial-actinomycetes associations

    NASA Astrophysics Data System (ADS)

    Ivanova, Ekaterina

    2013-04-01

    The weathering of sheet silicates is well known to be related to local and global geochemical cycles. Content and composition of clay minerals in soil determine the sorption properties of the soil horizons, water-holding capacity of the soil, stickiness, plasticity, etc. Microorganisms have a diverse range of mechanisms of minerals' structure transformation (acid- and alkali formation, biosorption, complexing, etc). One of the methods is an ability of exopolysaccharide-formation, in particular the formation of mucus, common to many bacteria, including cyanobacteria. Mucous covers cyanobacteria are the specific econiches for other bacteria, including actinomycetes. The objective was to analyze the structural changes of clay minerals under the influence of the cyanobacterial-actinomycetes associative growth. The objects of the study were: 1) the experimental symbiotic association, consisting of free-living heterocyst-formative cyanobacterium Anabaena variabilis Kutz. ATCC 294132 and actinomycete Streptomyces cyaneofuscatus FR837630, 2) rock samples obtained from the Museum of the Soil Science Department of the Lomonosov Moscow State University: kaolinite, consisting of kaolin (96%) Al4 (OH) 8 [Si4O10]; mixed with hydromica, chlorite and quartz; vermiculite, consisting of vermiculite (Ca, Mg, ...)*(Mg, Fe)3(OH)2[(Si, Al)4O10]*4H2O and trioctahedral mica (biotite). The mineralogical compositions of the rocks were determined by the universal X-ray Diffractometer Carl Zeiss Yena. The operationg regime was kept constant (30 kv, 40 mA). The cultivation of the association of actinomycete S. cyanoefuscatus and cyanobacterium A. variabilis caused a reduction in the intensity of kaolinite and hydromica reflexes. However, since both (mica and kaolinite) components have a rigid structure, the significant structural transformation of the minerals was not revealed. Another pattern was observed in the experiment, where the rock sample of vermiculite was used as the mineral

  17. Rhizocola hellebori gen. nov., sp. nov., an actinomycete of the family Micromonosporaceae containing 3,4-dihydroxydiaminopimelic acid in the cell-wall peptidoglycan.

    PubMed

    Matsumoto, Atsuko; Kawaguchi, Yoko; Nakashima, Takuji; Iwatsuki, Masato; Ōmura, Satoshi; Takahashi, Yōko

    2014-08-01

    An actinomycete strain, K12-0602(T), was isolated from the root of a Helleborus orientalis plant in Japan. The 16S rRNA gene sequence of strain K12-0602(T) showed that it had a close relationship with members of the family Micromonosporaceae and the 16S rRNA gene sequence similarity values between strain K12-0602(T) and type strains of type species of 27 genera belonging to the family Micromonosporaceae were below 96.2%. MK-9 (H4) and MK-9 (H6) were detected as major menaquinones, and galactose, xylose, mannose and ribose were present in the whole-cell hydrolysate. The acyl type of the peptidoglycan was glycolyl. Major fatty acids were iso-C(15 : 0), iso-C(16 : 0), C(17 : 1)ω9c and anteiso-C(17 : 0). Phosphatidylethanolamine was detected as the phospholipid corresponding to phospholipid type II. The G+C content of the genomic DNA was 67 mol%. Analyses of the cell-wall peptidoglycan by TLC and LC/MS showed that it was composed of alanine, glycine, hydroxylglutamic acid and an unknown amino acid, which was subsequently determined to be 3,4-dihydroxydiaminopimelic acid using instrumental analyses, including NMR and mass spectrometry. On the basis of the phylogenetic analysis and chemotaxonomic characteristics, strain K12-0602(T) represents a novel species of a new genus in the family Micromonosporaceae, for which the name Rhizocola hellebori gen. nov., sp. nov. is proposed. The type strain of the type species is K12-0602(T) ( = NBRC 109834(T) = DSM 45988(T)). This is the first report, to our knowledge, of 3,4-dihydroxydiaminopimelic acid being found as a diamino acid in bacterial cell-wall peptidoglycan.

  18. Pentacyclic antibiotics from a tidal mud flat-derived actinomycete.

    PubMed

    Moon, Kyuho; Chung, Beomkoo; Shin, Yoonho; Rheingold, Arnold L; Moore, Curtis E; Park, Sung Jean; Park, Sunghyouk; Lee, Sang Kook; Oh, Ki-Bong; Shin, Jongheon; Oh, Dong-Chan

    2015-03-27

    The combination of investigating a unique source of chemically prolific bacterium with an LC/MS-based bacterial strain selection approach resulted in the discovery of two new secondary metabolites, buanmycin (1) and buanquinone (2), from the culture of a marine Streptomyces strain, which was isolated from a tidal mudflat in Buan, Republic of Korea. The carbon backbone of buanmycin (1), comprising 20 quaternary carbons out of 30 total carbons, was determined via (13)C-(13)C COSY NMR analysis after labeling 1 with (13)C by culturing the bacterium with (13)C-glucose. The complete structure of 1 was confidently elucidated, primarily based on 1D and 2D NMR spectroscopic and X-ray crystallographic analysis, as that of a new pentacyclic xanthone. The absolute configuration of the α-methyl serine unit in 1 was established by applying the advanced Marfey's method. The structure of buanquinone (2) was determined to be a new pentacyclic quinone based on NMR and MS spectroscopic data. Buanmycin exhibited potent cytotoxicity against colorectal carcinoma cells (HCT-116) and gastric carcinoma cells (SNU-638) with submicromolar IC50 values and strongly inhibited the pathogenic Gram-negative bacterium Salmonella enterica (MIC = 0.7 μM). In particular, buanmycin demonstrated inhibition of sortase A, which is a promising target for antibiotic discovery.

  19. Streptomyces xinjiangensis sp. nov., an actinomycete isolated from Lop Nur region.

    PubMed

    Cheng, Cong; Li, Yu-Qian; Asem, Mipeshwaree Devi; Lu, Chun-Yan; Shi, Xiao-Han; Chu, Xiao; Zhang, Wan-Qin; Di An, Deng-; Li, Wen-Jun

    2016-10-01

    A novel actinobacterial strain, designated LPA192(T), was isolated from a soil sample collected from Lop Nur, Xinjiang Uygur Autonomous Region, Northwest China. A polyphasic approach was used to investigate the taxonomic position of strain LPA192(T). The isolate showed morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. Peptidoglycan was found to contain LL-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were MK-9(H6) and MK-10(H4). Polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylinositol. Major cellular fatty acids consist of C16:0, anteiso-C15:0 and C18:1 ω9c. The sugar in whole-cell hydrolysates was mannose. Phylogenetic analysis indicated that strain LPA192(T) is closely related to Streptomyces tanashiensis LMG 20274(T) (99.3 %), Streptomyces gulbargensis DAS131(T) (99.3 %), Streptomyces nashvillensis NBRC 13064(T) (99.3 %), Streptomyces roseolus NBRC 12816(T) (99.2 %) and Streptomyces filamentosus NBRC 12767(T) (99.1 %) while showing below 98.5 % sequencing similarities with other validly published Streptomyces species. However, DNA-DNA relatedness values between LPA192(T) and the closely related type strains were below 40 %, which are much lower than 70 % threshold value for species delineation. The genomic DNA G + C content of strain LPA192(T) was 69.3 mol %. Based on the differences in genotypic and phenotypic characteristics from the closely related strains, strain LPA192(T) is considered to represent a novel species of the genus Streptomyces for which the name Streptomyces xinjiangensis sp. nov. is proposed. The type strain is LPA192(T) (=KCTC 39601(T) = CGMCC 4.7288(T)).

  20. Application of statistical experimental design for optimisation of bioinsecticides production by sporeless Bacillus thuringiensis strain on cheap medium.

    PubMed

    Ben Khedher, Saoussen; Jaoua, Samir; Zouari, Nabil

    2013-01-01

    In order to overproduce bioinsecticides production by a sporeless Bacillus thuringiensis strain, an optimal composition of a cheap medium was defined using a response surface methodology. In a first step, a Plackett-Burman design used to evaluate the effects of eight medium components on delta-endotoxin production showed that starch, soya bean and sodium chloride exhibited significant effects on bioinsecticides production. In a second step, these parameters were selected for further optimisation by central composite design. The obtained results revealed that the optimum culture medium for delta-endotoxin production consists of 30 g L(-1) starch, 30 g L(-1) soya bean and 9 g L(-1) sodium chloride. When compared to the basal production medium, an improvement in delta-endotoxin production up to 50% was noted. Moreover, relative toxin yield of sporeless Bacillus thuringiensis S22 was improved markedly by using optimised cheap medium (148.5 mg delta-endotoxins per g starch) when compared to the yield obtained in the basal medium (94.46 mg delta-endotoxins per g starch). Therefore, the use of optimised culture cheap medium appeared to be a good alternative for a low cost production of sporeless Bacillus thuringiensis bioinsecticides at industrial scale which is of great importance in practical point of view.

  1. A systematic optimization of design parameters in strained silicon waveguides to further enhance the linear electro-optic effect

    NASA Astrophysics Data System (ADS)

    Olivares, Irene; Angelova, Todora I.; Pinilla-Cienfuegos, Elena; Sanchis, Pablo

    2016-05-01

    The electro-optic Pockels effect may be generated in silicon photonics structures by breaking the crystal symmetry by means of a highly stressing cladding layer (typically silicon nitride, SiN) deposited on top of the silicon waveguide. In this work, the influence of the waveguide parameters on the strain distribution and its overlap with the optical mode to enhance the Pockels effect has been analyzed. The optimum waveguide structure have been designed based on the definition and quantification of a figure of merit. The fabrication of highly stressing SiN layers by PECVD has also been optimized to characterize the designed structures. The residual stress has been controlled during the growth process by analyzing the influence of the main deposition parameters. Therefore, two identical samples with low and high stress conditions were fabricated and electro-optically characterized to test the induced Pockels effect and the influence of carrier effects. Electro-optical modulation was only measured in the sample with the high stressing SiN layer that could be attributed to the Pockels effect. Nevertheless, the influence of carriers were also observed thus making necessary additional experiments to decouple both effects.

  2. Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study

    PubMed Central

    AUNMEUNGTONG, W.; KHONGKHUNTHIAN, P.; RUNGSIYAKULL, P.

    2016-01-01

    SUMMARY Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Materials and methods Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. Results There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Conclusions Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Clinical implications Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant

  3. Biogeography of Actinomycete Communities and Type II Polyketide Synthase Genes in Soils Collected in New Jersey and Central Asia▿

    PubMed Central

    Wawrik, Boris; Kutliev, Djumaniyaz; Abdivasievna, Urinova A.; Kukor, Jerome J.; Zylstra, Gerben J.; Kerkhof, Lee

    2007-01-01

    Soil microbial communities are believed to be comprised of thousands of different bacterial species. One prevailing idea is that “everything is everywhere, and the environment selects,” implying that all types of bacteria are present in all environments where their growth requirements are met. We tested this hypothesis using actinomycete communities and type II polyketide synthase (PKS) genes found in soils collected from New Jersey and Uzbekistan (n = 91). Terminal restriction fragment length polymorphism analysis using actinomycete 16S rRNA and type II PKS genes was employed to determine community profiles. The terminal fragment frequencies in soil samples had a lognormal distribution, indicating that the majority of actinomycete phylotypes and PKS pathways are present infrequently in the environment. Less than 1% of peaks were detected in more than 50% of samples, and as many as 18% of the fragments were unique and detected in only one sample. Actinomycete 16S rRNA fingerprints clustered by country of origin, indicating that unique populations are present in North America and Central Asia. Sequence analysis of type II PKS gene fragments cloned from Uzbek soil revealed 35 novel sequence clades whose levels of identity to genes in the GenBank database ranged from 68 to 92%. The data indicate that actinomycetes are patchily distributed but that distinct populations are present in North American and Central Asia. These results have implications for microbial bioprospecting and indicate that the cosmopolitan actinomycete species and PKS pathways may account for only a small proportion of the total diversity in soil. PMID:17337547

  4. The Marine Actinomycete Genus Salinispora: A Model Organism for Secondary Metabolite Discovery

    PubMed Central

    Jensen, Paul R.; Moore, Bradley S.; Fenical, William

    2015-01-01

    This review covers the initial discovery of the marine actinomycete genus Salinispora through its development as a model for natural product research. A focus is placed on the novel chemical structures reported with reference to their biological activities and the synthetic and biosynthetic studies they have inspired. The time line of discoveries progresses from more traditional bioassay-guided approaches through the application of genome mining and genetic engineering techniques that target the products of specific biosynthetic gene clusters. This overview exemplifies the extraordinary biosynthetic diversity that can emanate from a narrowly defined genus and supports future efforts to explore marine taxa in the search for novel natural products. PMID:25730728

  5. A New Benzofuran Glycoside and Indole Alkaloids from a Sponge-Associated Rare Actinomycete, Amycolatopsis sp.

    PubMed Central

    Kwon, Yun; Kim, Seong-Hwan; Shin, Yoonho; Bae, Munhyung; Kim, Byung-Yong; Lee, Sang Kook; Oh, Ki-Bong; Shin, Jongheon; Oh, Dong-Chan

    2014-01-01

    Three new secondary metabolites, amycofuran (1), amycocyclopiazonic acid (2), and amycolactam (3), were isolated from the sponge-associated rare actinomycete Amycolatopsis sp. Based on combined spectroscopic analyses, the structures of 1–3 were determined to be a new benzofuran glycoside and new indole alkaloids related to cyclopiazonic acids, a class that has previously only been reported in fungi. The absolute configurations of 1 and 3 were deduced by ECD calculations, whereas that of 2 was determined using the modified Mosher method. Amycolactam (3) displayed significant cytotoxicity against the gastric cancer cell line SNU638 and the colon cancer cell line HCT116. PMID:24759001

  6. Biocontrol of Rhizoctonia solani damping-off and promotion of tomato plant growth by endophytic actinomycetes isolated from native plants of Algerian Sahara.

    PubMed

    Goudjal, Yacine; Toumatia, Omrane; Yekkour, Amine; Sabaou, Nasserdine; Mathieu, Florence; Zitouni, Abdelghani

    2014-01-20

    Thirty-four endophytic actinomycetes were isolated from the roots of native plants of the Algerian Sahara. Morphological and chemical studies showed that twenty-nine isolates belonged to the Streptomyces genus and five were non-Streptomyces. All isolates were screened for their in vitro antifungal activity against Rhizoctonia solani. The six that had the greatest pathogen inhibitory capacities were subsequently tested for their in vivo biocontrol potential on R. solani damping-off in sterilized and non-sterilized soils, and for their plant-growth promoting activities on tomato seedlings. In both soils, coating tomato seeds with antagonistic isolates significantly reduced (P<0.05) the severity of damping-off of tomato seedlings. Among the isolates tested, the strains CA-2 and AA-2 exhibited the same disease incidence reduction as thioperoxydicarbonic diamide, tetramethylthiram (TMTD) and no significant differences (P<0.05) were observed. Furthermore, they resulted in a significant increase in the seedling fresh weight, the seedling length and the root length of the seed-treated seedlings compared to the control. The taxonomic position based on 16S rDNA sequence analysis and phylogenetic studies indicated that the strains CA-2 and AA-2 were related to Streptomyces mutabilis NBRC 12800(T) (100% of similarity) and Streptomyces cyaneofuscatus JCM 4364(T) (100% of similarity), respectively.

  7. The gastric caeca of pentatomids as a house for actinomycetes

    PubMed Central

    2012-01-01

    Background Microbes are extensively associated with insects, playing key roles in insect defense, nutrition and reproduction. Most of the associations reported involve Proteobacteria. Despite the fact that Actinobacteria associated with insects were shown to produce antibiotic barriers against pathogens to the hosts or to their food and nutrients, there are few studies focusing on their association with insects. Thus, we surveyed the Actinobacteria diversity on a specific region of the midgut of seven species of stinkbugs (Hemiptera: Pentatomidae) known to carry a diversity of symbiotically-associated Proteobacteria. Results A total of 34 phylotypes were placed in 11 different Actinobacteria families. Dichelops melacanthus held the highest diversity with six actinobacteria families represented by nine phylotypes. Thyanta perditor (n = 7), Edessa meditabunda (n = 5), Loxa deducta (n = 4) and Pellaea stictica (n = 3) were all associated with three families. Piezodorus guildini (n = 3) and Nezara viridula (n = 3) had the lowest diversity, being associated with two (Propionibacteriaceae and Mycobacteriaceae) and one (Streptomyceataceae) families, respectively. Corynebacteriaceae and Mycobacteriaceae were the most common families with phylotypes from three different insect species each one. Conclusions Many phylotypes shared a low 16S rRNA gene similarity with their closest type strains and formed new phyletic lines on the periphery of several genera. This is a strong indicative that stinkbug caeca can harbor new species of actinobacteria, which might be derived from specific associations with the species of stinkbugs studied. Although the well-known role of actinobacteria as a source of biomolecules, the ecological features of these symbionts on the stinkbugs biology remain unknown. PMID:22682021

  8. Streptomyces manipurensis sp. nov., a novel actinomycete isolated from a limestone deposit site in Manipur, India.

    PubMed

    Nimaichand, Salam; Zhu, Wen-Yong; Yang, Ling-Ling; Ming, Hong; Nie, Guo-Xing; Tang, Shu-Kun; Ningthoujam, Debananda S; Li, Wen-Jun

    2012-06-01

    A novel actinobacterium, designated MBRL 201(T), was isolated from a sample collected from a limestone quarry at Hundung, Manipur, India. The strain was characterized using polyphasic taxonomy. Comparison of the 16S rRNA gene sequence of strain MBRL 201(T) and other Streptomyces species showed sequence similarities ranging from 93.0 to 99.6 % and strain MBRL 201(T) showed closest similarities to Streptomyces virginiae NBRC 12827(T) (99.6 %) and Streptomyces cinnamonensis NBRC 15873(T) (99.6 %). The DNA relatedness between MBRL 201(T) and the type strains of S. virginiae NBRC 12827(T) and S. cinnamonensis NBRC 15873(T) were 44.5 and 35.6 % respectively. Strain MBRL 201(T) contained LL: -diaminopimelic acid (A(2)pm) as the diagnostic diamino acid, with glucose as the main sugar, while small amounts of galactose, glucose, mannose, rhamnose, ribose and xylose were also present in cell-wall hydrolysates. The major fatty acids identified were anteiso-C(15:0) (38.9 %), iso-C(15:0) (19.9 %) and anteiso-C(17:1) (14.7 %). The predominant menaquinones detected were MK-9(H(6)) and MK-9(H(8)), while the polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositolmannosides, with other unknown phospholipids and lipids. The G+C content of the genomic DNA was 72.9 %. The phenotypic and genotypic data showed that strain MBRL 201(T) merits recognition as a representative of a novel species of the genus Streptomyces. It is proposed that the isolate should be classified in the genus Streptomyces as a novel species, Streptomyces manipurensis sp. nov. The type strain is MBRL 201(T) (=DSM 42029(T) = JCM 17351(T)).

  9. Antibacterial potential of streptomycete strains from Antarctic soils.

    PubMed

    Encheva-Malinova, Marta; Stoyanova, Mariya; Avramova, Hristina; Pavlova, Yanitsa; Gocheva, Blagovesta; Ivanova, Iskra; Moncheva, Penka

    2014-07-04

    The exploration of habitats with unusual environment and poorly explored areas such as Antarctica is one of the strategies for discovery of new biologically active substances and/or new producers. The aim of this study was to identify the actinomycetes isolated from the soils of the island Livingston - Antarctica and to investigate their potential to synthesize antibacterial agents against phytopathogens. Twenty-three actinomycete strains were the object of this study. Using PCR (polymerase chain reaction) amplification all strains were affiliated to genus Streptomyces. The sequencing of the 16S rRNA for three of the strains showed greatest similarity to Streptomyces tendae for one of them, and revealed that the other strains had closest relations to streptomycetes isolated from anthropogenically unaltered regions including Antarctica. The isolates were studied for production of antibacterial substances both by molecular and culture methods. PCR targeting specific biosynthetic genes involved in the production of some groups of antibiotics was performed. The screening showed that all strains possessed the gene for Type-II polyketide synthase, 11 strains - for non-ribosomal peptide synthetase; 6 strains - for polyene antibiotics; and 4 strains - for glycopeptide antibiotics. The production of antibacterial substances by the strains was tested in vitro against phytopathogenic bacteria. The strains differed in the number of inhibited test - bacteria and in their spectrum of action. Four strains showed a wide range of activity against Gram-positive and Gram-negative phytopathogens. The results obtained revealed that the Antarctic soils are potential source for isolation of streptomycetes producing antibiotics from different groups.

  10. Natural and engineered biosynthesis of nucleoside antibiotics in Actinomycetes.

    PubMed

    Chen, Wenqing; Qi, Jianzhao; Wu, Pan; Wan, Dan; Liu, Jin; Feng, Xuan; Deng, Zixin

    2016-03-01

    Nucleoside antibiotics constitute an important family of microbial natural products bearing diverse bioactivities and unusual structural features. Their biosynthetic logics are unique with involvement of complex multi-enzymatic reactions leading to the intricate molecules from simple building blocks. Understanding how nature builds this family of antibiotics in post-genomic era sets the stage for rational enhancement of their production, and also paves the way for targeted persuasion of the cell factories to make artificial designer nucleoside drugs and leads via synthetic biology approaches. In this review, we discuss the recent progress and perspectives on the natural and engineered biosynthesis of nucleoside antibiotics.

  11. Optimization of Magnetosome Production and Growth by the Magnetotactic Vibrio Magnetovibrio blakemorei Strain MV-1 through a Statistics-Based Experimental Design

    PubMed Central

    Silva, Karen T.; Leão, Pedro E.; Abreu, Fernanda; López, Jimmy A.; Gutarra, Melissa L.; Farina, Marcos; Bazylinski, Dennis A.; Freire, Denise M. G.

    2013-01-01

    The growth and magnetosome production of the marine magnetotactic vibrio Magnetovibrio blakemorei strain MV-1 were optimized through a statistics-based experimental factorial design. In the optimized growth medium, maximum magnetite yields of 64.3 mg/liter in batch cultures and 26 mg/liter in a bioreactor were obtained. PMID:23396329

  12. Siderophore production by actinomycetes isolates from two soil sites in Western Australia.

    PubMed

    Lee, Joanna; Postmaster, Armin; Soon, Hooi Peng; Keast, David; Carson, Kerry C

    2012-04-01

    The actinomycetes are metabolically flexible soil micro-organisms capable of producing a range of compounds of interest, including siderophores. Siderophore production by actinomycetes sampled from two distinct and separate geographical sites in Western Australia were investigated and found to be generally similar in the total percentage of siderophore producers found. The only notable difference was the proportion of isolates producing catechol siderophores with only 3% found in site 1 (from the north-west of Western Australia and reportedly containing 40% magnetite) and 17% in site 2 (a commercial stone fruit orchard in the hills east of Perth with a soil base ranging from sandy loam to laterite). Further detailed characterization of isolates of interest identified a Streptomyces that produced extracellularly excreted enterobactin, the characteristic Enterobacteriaceae siderophore, and also revealed some of the conditions required for enterobactin production. Carriage of the entF gene, which codes for the synthetase responsible for the final assembly of the tri-cyclic structure of enterobactin, was confirmed by PCR in this isolate. Another separate Streptomyces produced a compound that matched the UV/VIS spectra of heterobactin, a siderophore previously only described in Rhodococcus and Nocardia.

  13. The genus Nonomuraea: A review of a rare actinomycete taxon for novel metabolites.

    PubMed

    Sungthong, Rungroch; Nakaew, Nareeluk

    2015-05-01

    The genus Nonomuraea is a rare actinomycete taxon with a long taxonomic history, while its generic description was recently emended. The genus is less known among the rare actinomycete genera as its taxonomic position was revised several times. It can be found in diverse ecological niches, while most of its member species were isolated from soil samples. However, new trends to discover the genus in other habitats are increasing. Generic abundance of the genus was found to be dependent on geographical changes. Novel sources together with selective and invented isolation techniques might increase a chance to explore the genus and its novel candidates. Interestingly, some of its members have been revealed as a valuable source of novel metabolites for medical and industrial purposes. Broad-range of potent bioactive compounds including antimicrobial, anticancer, and antipsychotic substances, broad-spectrum antibiotics and biocatalysts can be synthesized by the genus. In order to investigate biosynthetic pathways of the bioactive compounds and self-resistant mechanisms to these compounds, the links from genes to metabolites have yet been needed for further discovery and biotechnological development of the genus Nonomuraea.

  14. Multiplexed site-specific genome engineering for overproducing bioactive secondary metabolites in actinomycetes.

    PubMed

    Li, Lei; Zheng, Guosong; Chen, Jun; Ge, Mei; Jiang, Weihong; Lu, Yinhua

    2017-03-01

    Actinomycetes produce a large variety of pharmaceutically active compounds, yet production titers often require to be improved for discovery, development and large-scale manufacturing. Here, we describe a new technique, multiplexed site-specific genome engineering (MSGE) via the 'one integrase-multiple attB sites' concept, for the stable integration of secondary metabolite biosynthetic gene clusters (BGCs). Using MSGE, we achieved five-copy chromosomal integration of the pristinamycin II (PII) BGC in Streptomyces pristinaespiralis, resulting in the highest reported PII titers in flask and batch fermentations (2.2 and 2g/L, respectively). Furthermore, MSGE was successfully extended to develop a panel of powerful Streptomyces coelicolor heterologous hosts, in which up to four copies of the BGCs for chloramphenicol or anti-tumour compound YM-216391 were efficiently integrated in a single step, leading to significantly elevated productivity (2-23 times). Our multiplexed approach holds great potential for robust genome engineering of industrial actinomycetes and novel drug discovery by genome mining.

  15. Old meets new: using interspecies interactions to detect secondary metabolite production in actinomycetes.

    PubMed

    Seyedsayamdost, Mohammad R; Traxler, Matthew F; Clardy, Jon; Kolter, Roberto

    2012-01-01

    Actinomycetes, a group of filamentous, Gram-positive bacteria, have long been a remarkable source of useful therapeutics. Recent genome sequencing and transcriptomic studies have shown that these bacteria, responsible for half of the clinically used antibiotics, also harbor a large reservoir of gene clusters, which have the potential to produce novel secreted small molecules. Yet, many of these clusters are not expressed under common culture conditions. One reason why these clusters have not been linked to a secreted small molecule lies in the way that actinomycetes have typically been studied: as pure cultures in nutrient-rich media that do not mimic the complex environments in which these bacteria evolved. New methods based on multispecies culture conditions provide an alternative approach to investigating the products of these gene clusters. We have recently implemented binary interspecies interaction assays to mine for new secondary metabolites and to study the underlying biology of interactinomycete interactions. Here, we describe the detailed biological and chemical methods comprising these studies.

  16. Structural and functional properties of actinomycetal communities in chernozems and saline soils of Ukraine

    NASA Astrophysics Data System (ADS)

    Grishko, V. N.; Syshchikova, O. V.

    2010-02-01

    In the profiles of ordinary and southern chernozems, the total numbers of amylolytic microorganisms and actinomycetes decreased with the depth by 2.4-4.2 and 3.4 times, respectively; in the profiles of solonetz and solonchak soils, by 4.2-5.3 and 4.8 times, respectively. In the genetic horizons of the ordinary and southern chernozems, the share of actinomycetes amounted to 29-30% of the total population of microorganisms; in the saline soils, it increases with the depth from 23 to 43%. In the chernozems, Streptomyces violaceomaculatus (Roseus section), St. sporoherbeus (Azureus), St. aerionidulus (Cinereus), St. enduracidicus (Cinereus), and St. grisinus (Cinereus) predominated; in the saline soils, St. violaceomaculatus and St. aerionidulus prevailed. In the ordinary chernozem, the Berger-Parker index was 1.5 times higher than in the southern chernozem. High similarity was found between the streptomycete communities in the chernozems (the Sorensen coefficient was 0.78). In the solonetzes, the species richness of the streptomycetes was higher by 1.7 times than in the solonchaks. In the chernozems, the similarity of the streptomycete communities was higher than in the solonchaks (0.78 and 0.60, respectively).

  17. Genome sequencing reveals complex secondary metabolome in themarine actinomycete Salinispora tropica

    SciTech Connect

    Udwary, Daniel W.; Zeigler, Lisa; Asolkar, Ratnakar; Singan,Vasanth; Lapidus, Alla; Fenical, William; Jensen, Paul R.; Moore, BradleyS.

    2007-05-01

    Recent fermentation studies have identified actinomycetes ofthe marine-dwelling genus Salinispora as prolific natural productproducers. To further evaluate their biosynthetic potential, we analyzedall identifiable secondary natural product gene clusters from therecently sequenced 5,184,724 bp S. tropica CNB-440 circular genome. Ouranalysis shows that biosynthetic potential meets or exceeds that shown byprevious Streptomyces genome sequences as well as other naturalproduct-producing actinomycetes. The S. tropica genome features ninepolyketide synthase systems of every known formally classified family,non-ribosomal peptide synthetases and several hybrid clusters. While afew clusters appear to encode molecules previously identified inStreptomyces species,the majority of the 15 biosynthetic loci are novel.Specific chemical information about putative and observed natural productmolecules is presented and discussed. In addition, our bioinformaticanalysis was critical for the structure elucidation of the novelpolyenemacrolactam salinilactam A. This study demonstrates the potentialfor genomic analysis to complement and strengthen traditional naturalproduct isolation studies and firmly establishes the genus Salinispora asa rich source of novel drug-like molecules.

  18. Phosphatic precipitates associated with actinomycetes in speleothems from Grand Cayman, British West Indies

    NASA Astrophysics Data System (ADS)

    Jones, Brian

    2009-07-01

    Calcitic speleothems from a cave located on the north central coast of Grand Cayman commonly include corrosion surfaces that developed when calcite precipitation ceased and corrosion mediated by condensates became the operative process. Dissolution features associated with these surfaces, including etched crystal surfaces, microcavities, and solution-widened boundaries between crystals, are commonly occupied by microbes and microbial mats that have been replaced by calcium phosphate and/or coated with calcium phosphate. No mineralized microbes were found in the calcite crystals that form the speleothems. The morphology of the mineralized hyphae (eight morphotypes) and spores (nine morphotypes) are indicative of actinomycetes, a group of microbes that are ideally adapted to life in oligotrophic cave environs. Superb preservation of the delicate hyphae, aerial hyphae, and delicate ornamentation on the hyphae and spores indicate that the microbes underwent rapid mineralized while close to their original life positions. Although these actinomycetes were extremely susceptible to replacement by calcium phosphate, there is no evidence that they directly or indirectly controlled precipitation. Nevertheless, the association between the P-rich precipitates and microbes shows that the use of phosphorus as a proxy for seasonal climate changes in paleoclimate analyses must be treated with caution.

  19. Family of class I lantibiotics from actinomycetes and improvement of their antibacterial activities.

    PubMed

    Maffioli, Sonia I; Monciardini, Paolo; Catacchio, Bruno; Mazzetti, Carlo; Münch, Daniela; Brunati, Cristina; Sahl, Hans-Georg; Donadio, Stefano

    2015-04-17

    Lantibiotics, an abbreviation for "lanthionine-containing antibiotics", interfere with bacterial metabolism by a mechanism not exploited by the antibiotics currently in clinical use. Thus, they have aroused interest as a source for new therapeutic agents because they can overcome existing resistance mechanisms. Starting from fermentation broth extracts preselected from a high-throughput screening program for discovering cell-wall inhibitors, we isolated a series of related class I lantibiotics produced by different genera of actinomycetes. Analytical techniques together with explorative chemistry have been used to establish their structures: the newly described compounds share a common 24 aa sequence with the previously reported lantibiotic planosporicin (aka 97518), differing at positions 4, 6, and 14. All of these compounds maintain an overall -1 charge at physiological pH. While all of these lantibiotics display modest antibacterial activity, their potency can be substantially modulated by progressively eliminating the negative charges, with the most active compounds carrying basic amide derivatives of the two carboxylates originally present in the natural compounds. Interestingly, both natural and chemically modified lantibiotics target the key biosynthetic intermediate lipid II, but the former compounds do not bind as effectively as the latter in vivo. Remarkably, the basic derivatives display an antibacterial potency and a killing effect similar to those of NAI-107, a distantly related actinomycete-produced class I lantibiotic which lacks altogether carboxyl groups and which is a promising clinical candidate for treating Gram-positive infections caused by multi-drug-resistant pathogens.

  20. Comparative genomics of actinomycetes with a focus on natural product biosynthetic genes

    PubMed Central

    2013-01-01

    Background Actinomycetes are a diverse group of medically, industrially and ecologically important bacteria, studied as much for the diseases they cause as for the cures they hold. The genomes of actinomycetes revealed that these bacteria have a large number of natural product gene clusters, although many of these are difficult to tie to products in the laboratory. Large scale comparisons of these clusters are difficult to perform due to the presence of highly similar repeated domains in the most common biosynthetic machinery: polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs). Results We have used comparative genomics to provide an overview of the genomic features of a set of 102 closed genomes from this important group of bacteria with a focus on natural product biosynthetic genes. We have focused on well-represented genera and determine the occurrence of gene cluster families therein. Conservation of natural product gene clusters within Mycobacterium, Streptomyces and Frankia suggest crucial roles for natural products in the biology of each genus. The abundance of natural product classes is also found to vary greatly between genera, revealing underlying patterns that are not yet understood. Conclusions A large-scale analysis of natural product gene clusters presents a useful foundation for hypothesis formulation that is currently underutilized in the field. Such studies will be increasingly necessary to study the diversity and ecology of natural products as the number of genome sequences available continues to grow. PMID:24020438

  1. Strain-driven and ultrasensitive resistive sensor/switch based on conductive alginate/nitrogen-doped carbon-nanotube-supported Ag hybrid aerogels with pyramid design.

    PubMed

    Zhao, Songfang; Zhang, Guoping; Gao, Yongju; Deng, Libo; Li, Jinhui; Sun, Rong; Wong, Ching-Ping

    2014-12-24

    Flexible strain-driven sensor is an essential component in the flexible electronics. Especially, high durability and sensitivity to strain are required. Here, we present an efficient and low-cost fabrication strategy to construct a highly sensitive and flexible pressure sensor based on a conductive, elastic aerogel with pyramid design. When pressure is loaded, the contact area between the interfaces of the conductive aerogel and the copper electrode as well as among the building blocks of the nitrogen-doped carbon-nanotube-supported Ag (N-CNTs/Ag) aerogel monoliths, changes in reversible and directional manners. This contact resistance mechanism enables the hybrid aerogels to act as strain-driven sensors with high sensitivity and excellent on/off swithching behavior, and the gauge factor (GF) is ∼15 under strain of 3%, which is superior to those reported for other aerogels. In addition, robust, elastomeric and conductive nanocomposites can be fabricated by injecting polydimethylsiloxane (PDMS) into alginate/N-CNTs/Ag aerogels. Importantly, the building blocks forming the aerogels retain their initial contact and percolation after undergoing large-strain deformation, PDMS infiltration, and cross-linking of PDMS, suggesting their potential applications as strain sensors.

  2. Synthetic Peptide Vaccine Development: Designing Dual Epitopes into a Single Pilin Peptide Immunogen Generates Antibody Cross-reactivity between Two Strains of Pseudomonas aeruginosa

    PubMed Central

    Hackbarth, Clifton; Hodges, Robert S.

    2010-01-01

    One of the main challenges of Pseudomonas aeruginosa (P. aeruginosa) vaccine development is the design of an antigen that elicits cross-reactive antibodies against multiple virulent strains. Using a rational design approach, we have developed a single 17-residue peptide immunogen that generates antibodies that target the receptor binding domain (RBD) of the type IV pilus of more than one strain of P. aeruginosa. Using the RBD sequence, of native strain PAO as a template, we have systematically changed up to five residues in the PAO sequence of the peptide immunogen, into that of the PAK sequence. We show by indirect and competitive ELISA, that the mutant peptide immunogens elicit the development of polyclonal sera that is cross-reactive to both native strain PAO and PAK pilin. We further show that there are at least two separate antibody populations in the polyclonal sera that possess closely-related epitopes but which are each strain specific. Moreover, part of the epitope for the PAO specific antibodies consists of several residues outside the disulfide loop of the receptor binding domain. This allows us to create two unique epitopes within the same receptor binding domain sequence. PMID:20807222

  3. Streptomyces songpinggouensis sp. nov., a Novel Actinomycete Isolated from Soil in Sichuan, China.

    PubMed

    Guan, Xuejiao; Li, Wenchao; Liu, Chongxi; Jin, Pinjiao; Guo, Siyu; Wang, Xiangjing; Xiang, Wensheng

    2016-12-01

    During a screening for novel and biotechnologically useful actinobacteria, a novel actinobacteria with weak antifungal activity, designated strain NEAU-Spg19(T), was isolated from a soil sample collected from pine forest in Songpinggou, Sichuan, southwest China. The strain was characterized using a polyphasic taxonomic approach which confirmed that it belongs to the genus Streptomyces. Growth occurred at a temperature range of 10-30 °C, pH 5.0-11.0 and NaCl concentrations of 0-5 %. The cell wall peptidoglycan consisted of LL-diaminopimelic acid and glycine. The major menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The phospholipid profile contained diphosphatidylglycerol (DPG), phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were iso-C15:0, iso-C16:0, and C16:0. 16S rRNA gene sequence similarity studies showed that strain NEAU-Spg19(T) belongs to the genus Streptomyces with the highest sequence similarities to Streptomyces tauricus JCM 4837(T) (98.6 %) and Streptomyces rectiviolaceus JCM 9092(T) (98.3 %). Some physiological and biochemical properties and low DNA-DNA relatedness values enabled the strain to be differentiated from S. tauricus JCM 4837(T) and S. rectiviolaceus JCM 9092(T). Hence, on the basis of phenotypic and genetic analyses, it is proposed that strain NEAU-Spg19(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces songpinggouensis sp. nov. is proposed. The type strain is NEAU-Spg19(T) (=CGMCC 4.7140(T)=DSM 42141(T)).

  4. Genes encoding ten newly designated OXA-63 group class D β-lactamases identified in strains of the pathogenic intestinal spirochaete Brachyspira pilosicoli.

    PubMed

    La, Tom; Neo, Eugene; Phillips, Nyree D; Hampson, David J

    2015-11-01

    The anaerobic spirochaete Brachyspira pilosicoli colonizes the large intestine of birds and mammals, including human beings, and may induce colitis and diarrhoea. B. pilosicoli has a recombinant population structure, and strains show extensive genomic rearrangements and different genome sizes. The resident chromosomal gene blaOXA-63 in B. pilosicoli encodes OXA-63, a narrow-spectrum group IV class D β-lactamase. Genes encoding four OXA-63 variants have been described in B. pilosicoli, and the current study was designed to investigate the distribution and diversity of such genes and proteins in strains of B. pilosicoli. PCRs were used to amplify blaOXA-63 group genes from 118 B. pilosicoli strains from different host species and geographical origins. One primer set was targeted externally to the gene and two sets were designed to amplify internal components. A total of 16 strains (13.6%) showed no evidence of possessing blaOXA-63 group genes, 44 (37.3%) had a full gene, 27 (22.9%) apparently had a gene but it failed to amplify with external primers, and 29 (24.6%) had only one or other of the two internal components amplified. Based on translation of the nucleotide sequences, ten new variants of the β-lactamase, designated OXA-470 through OXA-479, were identified amongst the 44 strains that had the full gene amplified. The 16 strains lacking blaOXA-63 group genes had a region of 1674 bp missing around where the gene was expected to reside. Despite apparent genomic rearrangements occurring in B. pilosicoli, positive selection pressures for conservation of blaOXA-63 group genes and OXA proteins appear to have been exerted.

  5. Verrucosispora fiedleri sp. nov., an actinomycete isolated from a fjord sediment which synthesizes proximicins.

    PubMed

    Goodfellow, Michael; Brown, Roselyn; Ahmed, Lina; Pathom-Aree, Wasu; Bull, Alan T; Jones, Amanda L; Stach, James E M; Zucchi, Tiago Domingues; Zhang, Lixin; Wang, Jian

    2013-03-01

    A novel filamentous actinobacterial organism, designated strain MG-37(T), was isolated from a Norwegian fjord sediment and examined using a polyphasic taxonomic approach. The organism was determined to have chemotaxonomic and morphological properties consistent with its classification in the genus Verrucosispora and formed a distinct phyletic line in the Verrucosispora 16S rRNA gene tree. It was most closely related to Verrucosispora maris DSM 45365(T) (99.5 % 16S rRNA gene similarity) and Verrucosispora gifhornensis DSM 44337(T) (99.4 % 16S rRNA gene similarity) but was distinguished from these strains based on low levels of DNA:DNA relatedness (~56 and ~50 %, respectively). It was readily delineated from all of the type strains of Verrucosispora species based on a combination of phenotypic properties. Isolate MG-37(T) (=NCIMB 14794(T) = NRRL-B-24892(T)) should therefore be classified as the type strain of a novel species of Verrucosispora for which the name Verrucosispora fiedleri is proposed.

  6. Degradation of softwood, hardwood, and grass lignocelluloses by two Steptomyces strains

    SciTech Connect

    Antai, S.P.; Crawford, D.L.

    1981-08-01

    Two Streptomyces strains, S. viridosporus T7A and S. setonii 75Vi2, were grown on softwood, hardwood, and grass lignocelluloses, and lignocellulose decomposition was followed by monitoring substrate weight loss, lignin loss, and carbohydrate loss over time. Results showed that both Streptomyces strains substantially degraded both the lignin and the carbohydrate components of each lignocellulose; however, these actinomycetes were more efficient decomposers of grass lignocelluloses than of hardwood or softwood lignocelluloses. In particular, these Streptomyces strains were more efficient decomposers of grass lignins than of hardwood or softwood lignins.

  7. Design of a new stretching apparatus and the effects of cyclic strain and substratum on mouse lung epithelial-12 cells.

    PubMed

    Arold, Stephen P; Wong, Joyce Y; Suki, Bela

    2007-07-01

    The pulmonary epithelium is exposed to mechanical strains during normal breathing or mechanical ventilation. While important for the regulation of cellular processes, excessive strains damage epithelial cells. To investigate the effects of strain on the epithelium, we developed a stretching device to apply equi-biaxial strains to cells cultured on elastic membranes. Following device validation, we exposed a murine epithelial cell line (MLE-12) to 30 min of cyclic stretch with 0, 25, 50, 75 and 100% change in surface area on pronectin or type I collagen coated membranes. Following stretch, we assessed cell viability using fluorescent immunocytochemisty and surfactant secretion using [(3)H] labeled phosphatidylcholine (PC). Cell injury increased with increasing strain with cells on pronectin showing more injury than on type I collagen. Stretching had no effect on surfactant secretion on either substratum suggesting MLE-12 cells are a poor model for stretch-induced surfactant secretion. The cells grown on pronectin, however, demonstrated a 3-fold increase in surfactant secretion compared to those grown on type I collagen at all strains. This suggests that, while this cell line does not demonstrate stretch-induced surfactant secretion, the underlying extracellular matrix plays a crucial factor in both cell death and signal transduction in response to strain.

  8. Design of a pulse-type strain gauge balance for a long-test-duration hypersonic shock tunnel

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Liu, Y.; Jiang, Z.

    2016-11-01

    When the measurement of aerodynamic forces is conducted in a hypersonic shock tunnel, the inertial forces lead to low-frequency vibrations of the model, and its motion cannot be addressed through digital filtering because a sufficient number of cycles cannot be obtained during a tunnel run. This finding implies restrictions on the model size and mass as the natural frequencies are inversely proportional to the length scale of the model. Therefore, the force measurement still has many problems, particularly for large and heavy models. Different structures of a strain gauge balance (SGB) are proposed and designed, and the measurement element is further optimized to overcome the difficulties encountered during the measurement of aerodynamic forces in a shock tunnel. The motivation for this study is to assess the structural performance of the SGB used in a long-test-duration JF12 hypersonic shock tunnel, which has more than 100 ms of test time. Force tests were conducted for a large-scale cone with a 10^° semivertex angle and a length of 0.75 m in the JF12 long-test-duration shock tunnel. The finite element method was used for the analysis of the vibrational characteristics of the Model-Balance-Sting System (MBSS) to ensure a sufficient number of cycles, particularly for the axial force signal during a shock tunnel run. The higher-stiffness SGB used in the test shows good performance, wherein the frequency of the MBSS increases because of the stiff construction of the balance. The experimental results are compared with the data obtained in another wind tunnel and exhibit good agreement at M = 7 and α =5°.

  9. In vivo strains in the femur of the Virginia opossum (Didelphis virginiana) during terrestrial locomotion: testing hypotheses of evolutionary shifts in mammalian bone loading and design.

    PubMed

    Butcher, Michael T; White, Bartholomew J; Hudzik, Nathan B; Gosnell, W Casey; Parrish, John H A; Blob, Richard W

    2011-08-01

    Terrestrial locomotion can impose substantial loads on vertebrate limbs. Previous studies have shown that limb bones from cursorial species of eutherian mammals experience high bending loads with minimal torsion, whereas the limb bones of non-avian reptiles (and amphibians) exhibit considerable torsion in addition to bending. It has been hypothesized that these differences in loading regime are related to the difference in limb posture between upright mammals and sprawling reptiles, and that the loading patterns observed in non-avian reptiles may be ancestral for tetrapod vertebrates. To evaluate whether non-cursorial mammals show loading patterns more similar to those of sprawling lineages, we measured in vivo strains in the femur during terrestrial locomotion of the Virginia opossum (Didelphis virginiana), a marsupial that uses more crouched limb posture than most mammals from which bone strains have been recorded, and which belongs to a clade phylogenetically between reptiles and the eutherian mammals studied previously. The presence of substantial torsion in the femur of opossums, similar to non-avian reptiles, would suggest that this loading regime likely reflects an ancestral condition for tetrapod limb bone design. Strain recordings indicate the presence of both bending and appreciable torsion (shear strain: 419.1 ± 212.8 με) in the opossum femur, with planar strain analyses showing neutral axis orientations that placed the lateral aspect of the femur in tension at the time of peak strains. Such mediolateral bending was unexpected for a mammal running with near-parasagittal limb kinematics. Shear strains were similar in magnitude to peak compressive axial strains, with opossum femora experiencing similar bending loads but higher levels of torsion compared with most previously studied mammals. Analyses of peak femoral strains led to estimated safety factor ranges of 5.1-7.2 in bending and 5.5-7.3 in torsion, somewhat higher than typical mammalian values

  10. A multiscale and multiphysics model of strain development in a 1.5 T MRI magnet designed with 36 filament composite MgB2 superconducting wire

    NASA Astrophysics Data System (ADS)

    Amin, Abdullah Al; Baig, Tanvir; Deissler, Robert J.; Yao, Zhen; Tomsic, Michael; Doll, David; Akkus, Ozan; Martens, Michael

    2016-05-01

    High temperature superconductors such as MgB2 focus on conduction cooling of electromagnets that eliminates the use of liquid helium. With the recent advances in the strain sustainability of MgB2, a full body 1.5 T conduction cooled magnetic resonance imaging (MRI) magnet shows promise. In this article, a 36 filament MgB2 superconducting wire is considered for a 1.5 T full-body MRI system and is analyzed in terms of strain development. In order to facilitate analysis, this composite wire is homogenized and the orthotropic wire material properties are employed to solve for strain development using a 2D-axisymmetric finite element analysis (FEA) model of the entire set of MRI magnet. The entire multiscale multiphysics analysis is considered from the wire to the magnet bundles addressing winding, cooling and electromagnetic excitation. The FEA solution is verified with proven analytical equations and acceptable agreement is reported. The results show a maximum mechanical strain development of 0.06% that is within the failure criteria of -0.6% to 0.4% (-0.3% to 0.2% for design) for the 36 filament MgB2 wire. Therefore, the study indicates the safe operation of the conduction cooled MgB2 based MRI magnet as far as strain development is concerned.

  11. Draft Genome Sequence of Brucella abortus S99: Designated Antigenic Smooth Reference Strain Used in Diagnostic Tests in India

    PubMed Central

    Shome, Rajeswari; Krithiga, Natesan; Padmashree, B. S.; Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S.; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rahman, Habibur

    2014-01-01

    Brucella abortus strain S99 is widely used for the preparation of colored, plain, recombinant and smooth lipopolysaccharide antigens for the preparation of Brucella diagnostic kits. The genome of this strain was sequenced and the length of the genome was 3,253,175 bp, with 57.2% G+C content. A total of 3,365 protein coding genes and 53 RNA genes were predicted. PMID:25146137

  12. Draft Genome Sequence of Brucella abortus S99: Designated Antigenic Smooth Reference Strain Used in Diagnostic Tests in India.

    PubMed

    Shome, Rajeswari; Krithiga, Natesan; Padmashree, B S; Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash; Rahman, Habibur

    2014-08-21

    Brucella abortus strain S99 is widely used for the preparation of colored, plain, recombinant and smooth lipopolysaccharide antigens for the preparation of Brucella diagnostic kits. The genome of this strain was sequenced and the length of the genome was 3,253,175 bp, with 57.2% G+C content. A total of 3,365 protein coding genes and 53 RNA genes were predicted.

  13. Switching antibiotics production on and off in actinomycetes by an IclR family transcriptional regulator from Streptomyces peucetius ATCC 27952.

    PubMed

    Chaudhary, Amit Kumar; Singh, Bijay; Maharjan, Sushila; Jha, Amit Kumar; Kim, Byung-Gee; Sohng, Jae Kyung

    2014-08-01

    Doxorubicin, produced by Streptomyces peucetius ATCC 27952, is tightly regulated by dnrO, dnrN, and dnrI regulators. Genome mining of S. peucetius revealed the presence of the IclR (doxR) type family of transcription regulator mediating the signal-dependent expression of operons at the nonribosomal peptide synthetase gene cluster. Overexpression of doxR in native strain strongly repressed the drug production. Furthermore, it also had a negative effect on the regulatory system of doxorubicin, wherein the transcript of dnrI was reduced to the maximum level in comparision with the other two. Interestingly, the overexpression of the same gene also had strong inhibitory effects on the production of actinorhodin (blue pigment) and undecylprodigiosin (red pigment) in Streptomyces coelicolor M145, herboxidiene production in Streptomyces chromofuscus ATCC 49982, and spinosyn production in Saccharopolyspora spinosa NRRL 18395, respectively. Moreover, DoxR exhibited pleiotropic effects on the production of blue and red pigments in S. coelicolor when grown in different agar media, wherein the production of blue pigment was inhibited in R2YE medium and the red pigment was inhibited in YEME medium. However, the production of both blue and red pigments from S. coelicolor harboring doxR was halted in ISP2 medium, whereas S. coelicolor produced both pigmented antibiotics in the same plate. These consequences demonstrate that the on and off production of these antibiotics was not due to salt stress or media compositions, but was selectively controlled in actinomycetes.

  14. Anti-malarial Activities of Two Soil Actinomycete Isolates from Sabah via Inhibition of Glycogen Synthase Kinase 3β

    PubMed Central

    Dahari, Dhiana Efani; Salleh, Raifana Mohamad; Mahmud, Fauze; Chin, Lee Ping; Embi, Noor; Sidek, Hasidah Mohd

    2016-01-01

    Exploiting natural resources for bioactive compounds is an attractive drug discovery strategy in search for new anti-malarial drugs with novel modes of action. Initial screening efforts in our laboratory revealed two preparations of soil-derived actinomycetes (H11809 and FH025) with potent anti-malarial activities. Both crude extracts showed glycogen synthase kinase 3β (GSK3β)-inhibitory activities in a yeast-based kinase assay. We have previously shown that the GSK3 inhibitor, lithium chloride (LiCl), was able to suppress parasitaemia development in a rodent model of malarial infection. The present study aims to evaluate whether anti-malarial activities of H11809 and FH025 involve the inhibition of GSK3β. The acetone crude extracts of H11809 and FH025 each exerted strong inhibition on the growth of Plasmodium falciparum 3D7 in vitro with 50% inhibitory concentration (IC50) values of 0.57 ± 0.09 and 1.28 ± 0.11 µg/mL, respectively. The tested extracts exhibited Selectivity Index (SI) values exceeding 10 for the 3D7 strain. Both H11809 and FH025 showed dosage-dependent chemo-suppressive activities in vivo and improved animal survivability compared to non-treated infected mice. Western analysis revealed increased phosphorylation of serine (Ser 9) GSK3β (by 6.79 to 6.83-fold) in liver samples from infected mice treated with H11809 or FH025 compared to samples from non-infected or non-treated infected mice. A compound already identified in H11809 (data not shown), dibutyl phthalate (DBP) showed active anti-plasmodial activity against 3D7 (IC50 4.87 ± 1.26 µg/mL which is equivalent to 17.50 µM) and good chemo-suppressive activity in vivo (60.80% chemo-suppression at 300 mg/kg body weight [bw] dosage). DBP administration also resulted in increased phosphorylation of Ser 9 GSK3β compared to controls. Findings from the present study demonstrate that the potent anti-malarial activities of H11809 and FH025 were mediated via inhibition of host GSK3β. In addition

  15. Fly's proprioception-inspired micromachined strain-sensing structure: idea, design, modeling and simulation, and comparison with experimental results

    NASA Astrophysics Data System (ADS)

    Wicaksono, D. H. B.; Zhang, L.-J.; Pandraud, G.; French, P. J.; Vincent, J. F. V.

    2006-04-01

    A new strain-sensing structure inspired from insect's (especially the Fly) propricoception sensor is devised. The campaniform sensillum is a strain-sensing microstructure with very high sensitivity despite its small dimension (diameter ~10 µm in a relatively stiff material of insect's exocuticle (E = ~109 Pa). Previous work shows that the high sensitivity of this structure towards strain is due to its membrane-in-recess- and strainconcentrating- hole- features. Based on this inspiration, we built similar structure using silicon micromachining technology. Then a simple characterisation setup was devised. Here, we present briefly, finite-element modeling and simulation based on this actual sample preparation for the characterisation. As comparison and also to understand mechanical features responsible for the strain-sensitivity, we performed the modeling on different mechanical structures: bulk chunk, blind-hole, thorugh-hole, surface membrane, and membrane-in-recess. The actual experimental characterisation was performed previously using optical technique to membranein- recess micromachined Si structure. The FEM simulation results confirm that the bending stress and strain are concentrated in the hole-vicinity. The membrane inside the hole acts as displacement transducer. The FEM is in conformity with previous analytical results, as well as the optical characterisation result. The end goal is to build a new type MEMS strain sensor.

  16. Metabolic engineering of antibiotic factories: new tools for antibiotic production in actinomycetes.

    PubMed

    Weber, Tilmann; Charusanti, Pep; Musiol-Kroll, Ewa Maria; Jiang, Xinglin; Tong, Yaojun; Kim, Hyun Uk; Lee, Sang Yup

    2015-01-01

    Actinomycetes are excellent sources for novel bioactive compounds, which serve as potential drug candidates for antibiotics development. While industrial efforts to find and develop novel antimicrobials have been severely reduced during the past two decades, the increasing threat of multidrug-resistant pathogens and the development of new technologies to find and produce such compounds have again attracted interest in this field. Based on improvements in whole-genome sequencing, novel methods have been developed to identify the secondary metabolite biosynthetic gene clusters by genome mining, to clone them, and to express them in heterologous hosts in much higher throughput than before. These technologies now enable metabolic engineering approaches to optimize production yields and to directly manipulate the pathways to generate modified products.

  17. Structural-functional specificity of the complexes of psychrotolerant soil actinomycetes

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Dubrova, M. S.; Zvyagintsev, D. G.

    2010-04-01

    The active growth and development of psychrotolerant actinomycetes take place in peat and podzolic soils of the tundra and taiga at temperatures below 10°C. The population density of psychrotolerant mycelial prokaryotes in these soils reaches thousands and tens of thousands of CFU/g of soil, and the length of their mycelium is up to 380 m/g of soil. The application of fluorescent in situ hybridization (the FISH method) demonstrated that the metabolically active psychrotolerant representatives of the phylogenetic group of Actinobacteria comprise up to 30% of the total number of bacteria in prokaryotic microbial communities of oligotrophic peat bog and podzolic soils. The portion of metabolically active mycelial actinobacteria exceeds the portion of unicellular actinobacteria. Psychrotolerant streptomycetes isolated from peat bog soils possess pectinolytic, amylolytic, and antagonistic activities at low temperatures (5°C).

  18. Design and proposal of dual line-of-defense perimeter watchdog incorporating optimally designed FBG based accelerometers and strain sensors using single optical fiber

    NASA Astrophysics Data System (ADS)

    Khan, Mohd. Mansoor; Sonkar, Ramesh Kumar

    2015-06-01

    Paper presents Opto-Mechanical intrusion sensor fence with FBGs attached to mechanical accelerometers and strain sensors, optimized on SolidWorks 2013 for desired frequency to 35 Hz, picking up accelerations/ strains and its deployment for perimeter security. The accelerometer structure consists of inertial mass supported by an L-shaped modified cantilever beam having non-uniform cross section area connected to base by a thin neck element which acts as strain concentrated centre hence an optimum zone for FBG sensors placement. Bragg wavelength shifts were obtained on Optigrating software for the obtained strain values on mechanical assembly of fence. CFD wind analysis is performed on the assembly to obtain the spot for accelerometer's placement to avoid false alarms up to wind velocities of 20 m/s.

  19. Effectiveness of a newly designed construction uniform for heat strain attenuation in a hot and humid environment.

    PubMed

    Yi, Wen; Chan, Albert P C; Wong, Francis K W; Wong, Del P

    2017-01-01

    This study aims to evaluate the effectiveness of a newly designed construction uniform in combating heat stress. Ten male volunteers performed treadmill running in a climatic chamber maintained at 34.5 °C temperature, 75% relative humidity, 0.3 m/s air velocity, and solar radiation of 450 W/m(2) that simulates typical summer working environment of construction sites in Hong Kong. The participants were tested while wearing two kinds of construction uniforms: a commonly worn uniform A, or a newly designed uniform B. It was found during exercise that Tc (38.34 ± 0.14 vs 38.45 ± 0.11 °C, p = 0.03), Tsk (36.01 ± 0.36 vs 36.27 ± 0.34 °C, p = 0.03), HR (162.7 ± 10.1 vs 172.5 ± 9.2 bpm, p < 0.01), PSI (7.0 ± 0.4 vs 7.5 ± 0.5, p = 0.04), thermal sensation (1.7 ± 0.9 vs 2.6 ± 0.7, p = 0.02), and wetness sensation (1.9 ± 0.9 vs 2.6 ± 0.8, p < 0.01) was lower when wearing uniform B than that of uniform A. It was found during recovery that Tc (37.89 ± 0.13 vs 38.06 ± 0.13 °C, p < 0.01), Tsk (35.68 ± 0.37 vs 36.02 ± 0.41 °C, p < 0.01), HR (104.2 ± 10.1 vs 112.6 ± 10.7 bpm, p < 0.01), PSI (3.3 ± 0.7 vs 4.1 ± 1.0, p < 0.01), thermal sensation (0.1 ± 0.9 vs 1.0 ± 0.8, p = 0.02), and wetness sensation (1.1 ± 1.0 vs 2.3 ± 0.8, p = 0.02) was lower when wearing uniform B than that of uniform A. The findings of this study suggested the newly designed construction uniform could reduce thermoregulatory and cardiovascular strain, and improve thermal comfort while exercising in a hot and humid environment.

  20. Novel tryptophan metabolism by a potential gene cluster that is widely distributed among actinomycetes.

    PubMed

    Ozaki, Taro; Nishiyama, Makoto; Kuzuyama, Tomohisa

    2013-04-05

    The characterization of potential gene clusters is a promising strategy for the identification of novel natural products and the expansion of structural diversity. However, there are often difficulties in identifying potential metabolites because their biosynthetic genes are either silenced or expressed only at a low level. Here, we report the identification of a novel metabolite that is synthesized by a potential gene cluster containing an indole prenyltransferase gene (SCO7467) and a flavin-dependent monooxygenase (FMO) gene (SCO7468), which were mined from the genome of Streptomyces coelicolor A3(2). We introduced these two genes into the closely related Streptomyces lividans TK23 and analyzed the culture broths of the transformants. This process allowed us to identify a novel metabolite, 5-dimethylallylindole-3-acetonitrile (5-DMAIAN) that was overproduced in the transformant. Biochemical characterization of the recombinant SCO7467 and SCO7468 demonstrated the novel L-tryptophan metabolism leading to 5-DMAIAN. SCO7467 catalyzes the prenylation of L-tryptophan to form 5-dimethylallyl-L-tryptophan (5-DMAT). This enzyme is the first actinomycetes prenyltransferase known to catalyze the addition of a dimethylallyl group to the C-5 of tryptophan. SCO7468 then catalyzes the conversion of 5-DMAT into 5-dimethylallylindole-3-acetaldoxime (5-DMAIAOx). An aldoxime-forming reaction catalyzed by the FMO enzyme was also identified for the first time in this study. Finally, dehydration of 5-DMAIAOx presumably occurs to yield 5-DMAIAN. This study provides insight into the biosynthesis of prenylated indoles that have been purified from actinomycetes.

  1. Rhodococcus sovatensis sp. nov., an actinomycete isolated from the hypersaline and heliothermal Lake Ursu.

    PubMed

    Táncsics, András; Máthé, István; Benedek, Tibor; Tóth, Erika M; Atasayar, Ewelina; Spröer, Cathrin; Márialigeti, Károly; Felföldi, Tamás; Kriszt, Balázs

    2017-02-01

    A Gram-stain-positive, strictly aerobic, mesophilic bacterium, designated H004T, was isolated from a water sample of the hypersaline and heliothermal Lake Ursu, Sovata, Romania. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain H004T formed a distinct phyletic lineage within the genus Rhodococcus. It shared the highest 16S rRNA gene sequence similarity with Rhodococcus yunnanensis YIM 70056T (98.80 %), followed by Rhodococcus fascians LMG 3623T (98.73 %), Rhodococcus cercidiphylli YIM 65003T (98.73 %), Rhodococcus cerastii C5T (98.58 %) and Rhodococcus kyotonensis DS472T (98.53 %). The alkB-based phylogenetic analysis further confirmed that this strain constitutes a highly unique lineage within the genus. Chemotaxonomic characteristics, including the predominant fatty acids acids C15 : 0, C18 : 1ω9c, C19 : 1ω11c/C19 : 1ω9c and C16 : 1ω7c/iso-C15 : 0 2-OH, the major quinone MK-8(H2), the presence of mycolic acids and cell-wall chemotype IV were also consistent with the properties of members of the genus Rhodococcus. The DNA G+C content of strain H004T was 65.4 mol%. The results of DNA-DNA hybridization analyses with the closest relatives, in combination with the alkB-based phylogenetic analysis, as well as the chemotaxonomic and physiological data, demonstrated that isolate H004T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus sovatensissp. nov. is proposed. The type strain is H004T (=DSM 102881T=NCAIM B.02632T).

  2. Designing and exploring active N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides against three Trypanosoma cruzi strains more prevalent in Chagas disease patients.

    PubMed

    Palace-Berl, Fanny; Pasqualoto, Kerly Fernanda Mesquita; Jorge, Salomão Dória; Zingales, Bianca; Zorzi, Rodrigo Rocha; Silva, Marcelo Nunes; Ferreira, Adilson Kleber; de Azevedo, Ricardo Alexandre; Teixeira, Sarah Fernandes; Tavares, Leoberto Costa

    2015-01-01

    Chagas disease affects around 8 million people worldwide and its treatment depends on only two nitroheterocyclic drugs, benznidazole (BZD) and nifurtimox (NFX). Both drugs have limited curative power in chronic phase of disease. Nifuroxazide (NF), a nitroheterocyclic drug, was used as lead to design a set of twenty one compounds in order to improve the anti-Trypanosoma cruzi activity. Lipinski's rules were considered in order to support drug-likeness designing. The set of N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides was assayed against three T. cruzi strains, which represent the discrete typing units more prevalent in human patients: Y (TcII), Silvio X10 cl1 (TcI), and Bug 2149 cl10 (TcV). All the derivatives, except one, showed enhanced trypanocidal activity against the three strains as compared to BZD. In the Y strain 62% of the compounds were more active than NFX. The most active compound was N'-((5-nitrofuran-2-yl) methylene)biphenyl-4-carbohydrazide (C20), which showed IC50 values of 1.17 ± 0.12 μM; 3.17 ± 0.32 μM; and 1.81 ± 0.18 μM for Y, Silvio X10 cl1, and Bug 2149 cl10 strains, respectively. Cytotoxicity assays with human fibroblast cells have demonstrated high selectivity indices for several compounds. Exploratory data analysis indicated that primarily topological, steric/geometric, and electronic properties have contributed to the discrimination of the set of investigated compounds. The findings can be helpful to drive the designing, and subsequently, the synthesis of additional promising drugs against Chagas disease.

  3. Simulation-based design of a strained graphene field effect transistor incorporating the pseudo magnetic field effect

    SciTech Connect

    Souma, Satofumi Ueyama, Masayuki; Ogawa, Matsuto

    2014-05-26

    We present a numerical study on the performance of strained graphene-based field-effect transistors. A local strain less than 10% is applied over a central channel region of the graphene to induce the shift of the Dirac point in the channel region along the transverse momentum direction. The left and the right unstrained graphene regions are doped to be either n-type or p-type. By using the atomistic tight-binding model and a Green's function method, we predict that the gate voltage applied to the central strained graphene region can switch the drain current on and off with an on/off ratio of more than six orders of magnitude at room temperature. This is in spite of the absence of a bandgap in the strained channel region. Steeper subthreshold slopes below 60 mV/decade are also predicted at room temperature because of a mechanism similar to the band-to-band tunneling field-effect transistors.

  4. Melanogenic actinomycetes from rhizosphere soil-antagonistic activity against Xanthomonas oryzae and plant-growth-promoting traits.

    PubMed

    Muangham, Supattra; Pathom-Aree, Wasu; Duangmal, Kannika

    2015-02-01

    A total of 210 melanogenic actinomycetes were isolated from 75 rhizospheric soils using ISP6 and ISP7 agar supplemented with antifungal and antibacterial agents. Their morphological characteristics and the presence of ll-diaminopimelic acid in whole-cell hydrolyzates revealed that all isolates belonged to the genus Streptomyces. Their ability to inhibit the growth of 2 pathogenic rice bacteria, Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola, was observed using the agar overlay method. The results indicated that 61.9% of the isolates could inhibit at least one of the tested rice pathogens. Among these, isolate TY68-3 showed the highest antibacterial activity and siderophore production. The 16S rRNA gene sequence analysis of 46 representative isolates revealed that isolates with high similarity to Streptomyces bungoensis were frequently found. The present study indicated the potential of melanogenic actinomycetes for use as biocontrol agents against X. oryzae as well as their diversity in rhizospheric soils.

  5. Study of the diversity of culturable actinomycetes in the North Pacific and Caribbean coasts of Costa Rica

    PubMed Central

    Solano, Godofredo; Rojas-Jiménez, Keilor; Jaspars, Marcel

    2011-01-01

    In this study, 137 actinomycetes were isolated from subtidal marine sediments in the North Pacific and Caribbean coasts of Costa Rica. Bioinformatics analysis of the 16S rRNA gene sequences assigned the isolates to 15 families and 21 genera. Streptomyces was the dominant genus while the remaining 20 genera were poorly represented. Nearly 70% of the phylotypes presented a coastal-restricted distribution whereas the other 30% were common inhabitants of both shores. The coastal tropical waters of Costa Rica showed a high diversity of actinomycetes, both in terms of the number of species and phylogenetic composition, although significant differences were observed between and within shores. The observed pattern of species distribution might be the result of several factors including the characteristics of the ecosystems, presence of endemic species and the influence of terrestrial runoff. PMID:19365710

  6. Distribution and generic composition of culturable marine actinomycetes from the sediments of Indian continental slope of Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Das, Surajit; Lyla, P. S.; Ajmal Khan, S.

    2008-05-01

    Actinomycetes population from continental slope sediment of the Bay of Bengal was studied. Samples were collected during two voyages of FORV Sagar Sampada in 2004 (May-June) and 2005 (July) respectively from 11 transects (each transect had ca. 200 m, 500 m, and 1 000 m depth stations). The physicochemical parameters of overlying water, and sediment samples were also recorded. The actinomycete population ranged from 5.17 to 51.94 CFU/g dry sediment weight and 9.38 to 45.22 CFU/g dry sediment weight during the two cruises respectively. No actinomycete colony was isolated from stations in 1 000 m depth. Two-way analysis of variance showed significant variation among stations (ANOVA two-way, P<0.05), but no significance was found between the two cruises (ANOVA two-way, P<0.05). Populations in stations in 500 m depth in both cruises were higher than that of 200 m depth stations with statistically insignificant difference (ANOVA two-way, P>0.05). Three actinomycetes genera were identified. Streptomyces was found to be the dominating one in both the cruises, followed by Micromonospora, and Actinomyces. The spore of Streptomyces isolates showed the abundance in spiral spore chain. Spore surface was smooth. Multiple regression analysis revealed that the influencing physico-chemical factors were sediment pH, sediment temperature, TOC, porosity, salinity, and pressure. The media used in the present study was prepared with seawater. Thus, they may represent an autochthonous marine flora and deny the theory of land runoff carriage into the sea for adaptation to the salinity of the seawater and sediments.

  7. Transformation of 2,4,6-trinitrotoluene (TNT) by actinomycetes isolated from TNT-contaminated and uncontaminated environments

    SciTech Connect

    Pasti-Grigsby, M.B.; Lewis, T.A.; Crawford, D.L.; Crawford, R.L.

    1996-03-01

    Biotransformation of TNT has been reported under both aerobic and anaerobic conditions. Actinomycetes are important decomposers in composts. This study examines the tolerance of acitomycete cultures, isolated from both TNT-contaminated and uncontaminated environments for different concentrations to TNT, determined how selected isolates transform TNT, and examined whether such TNT transformations were constitutive or induced by exposure to TNT. 33 refs., 1 figs., 1 tab.

  8. Strain Prioritization and Genome Mining for Enediyne Natural Products

    PubMed Central

    Yan, Xiaohui; Ge, Huiming; Huang, Tingting; Hindra; Yang, Dong; Teng, Qihui; Crnovčić, Ivana; Li, Xiuling; Rudolf, Jeffrey D.; Lohman, Jeremy R.; Gansemans, Yannick; Zhu, Xiangcheng; Huang, Yong; Zhao, Li-Xing; Jiang, Yi; Van Nieuwerburgh, Filip; Rader, Christoph

    2016-01-01

    ABSTRACT The enediyne family of natural products has had a profound impact on modern chemistry, biology, and medicine, and yet only 11 enediynes have been structurally characterized to date. Here we report a genome survey of 3,400 actinomycetes, identifying 81 strains that harbor genes encoding the enediyne polyketide synthase cassettes that could be grouped into 28 distinct clades based on phylogenetic analysis. Genome sequencing of 31 representative strains confirmed that each clade harbors a distinct enediyne biosynthetic gene cluster. A genome neighborhood network allows prediction of new structural features and biosynthetic insights that could be exploited for enediyne discovery. We confirmed one clade as new C-1027 producers, with a significantly higher C-1027 titer than the original producer, and discovered a new family of enediyne natural products, the tiancimycins (TNMs), that exhibit potent cytotoxicity against a broad spectrum of cancer cell lines. Our results demonstrate the feasibility of rapid discovery of new enediynes from a large strain collection. PMID:27999165

  9. Structural and Functional Characterizations of SsgB, a Conserved Activator of Developmental Cell Division in Morphologically Complex Actinomycetes*

    PubMed Central

    Xu, Qingping; Traag, Bjørn A.; Willemse, Joost; McMullan, Daniel; Miller, Mitchell D.; Elsliger, Marc-André; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Bakolitsa, Constantina; Carlton, Dennis; Chen, Connie; Chiu, Hsiu-Ju; Chruszcz, Maksymilian; Clayton, Thomas; Das, Debanu; Deller, Marc C.; Duan, Lian; Ellrott, Kyle; Ernst, Dustin; Farr, Carol L.; Feuerhelm, Julie; Grant, Joanna C.; Grzechnik, Anna; Grzechnik, Slawomir K.; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Kumar, Abhinav; Marciano, David; Minor, Wladek; Mommaas, A. Mieke; Morse, Andrew T.; Nigoghossian, Edward; Nopakun, Amanda; Okach, Linda; Oommachen, Silvya; Paulsen, Jessica; Puckett, Christina; Reyes, Ron; Rife, Christopher L.; Sefcovic, Natasha; Tien, Henry J.; Trame, Christine B.; van den Bedem, Henry; Wang, Shuren; Weekes, Dana; Hodgson, Keith O.; Wooley, John; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.; van Wezel, Gilles P.

    2009-01-01

    SsgA-like proteins (SALPs) are a family of homologous cell division-related proteins that occur exclusively in morphologically complex actinomycetes. We show that SsgB, a subfamily of SALPs, is the archetypal SALP that is functionally conserved in all sporulating actinomycetes. Sporulation-specific cell division of Streptomyces coelicolor ssgB mutants is restored by introduction of distant ssgB orthologues from other actinomycetes. Interestingly, the number of septa (and spores) of the complemented null mutants is dictated by the specific ssgB orthologue that is expressed. The crystal structure of the SsgB from Thermobifida fusca was determined at 2.6 Å resolution and represents the first structure for this family. The structure revealed similarities to a class of eukaryotic “whirly” single-stranded DNA/RNA-binding proteins. However, the electro-negative surface of the SALPs suggests that neither SsgB nor any of the other SALPs are likely to interact with nucleotide substrates. Instead, we show that a conserved hydrophobic surface is likely to be important for SALP function and suggest that proteins are the likely binding partners. PMID:19567872

  10. Nitrogen regulator GlnR controls uptake and utilization of non-phosphotransferase-system carbon sources in actinomycetes

    PubMed Central

    Liao, Cheng-Heng; Yao, Lili; Xu, Ya; Liu, Wei-Bing; Zhou, Ying; Ye, Bang-Ce

    2015-01-01

    The regulatory mechanisms underlying the uptake and utilization of multiple types of carbohydrates in actinomycetes remain poorly understood. In this study, we show that GlnR (central regulator of nitrogen metabolism) serves as a universal regulator of nitrogen metabolism and plays an important, previously unknown role in controlling the transport of non-phosphotransferase-system (PTS) carbon sources in actinomycetes. It was observed that GlnR can directly interact with the promoters of most (13 of 20) carbohydrate ATP-binding cassette (ABC) transporter loci and can activate the transcription of these genes in response to nitrogen availability in industrial, erythromycin-producing Saccharopolyspora erythraea. Deletion of the glnR gene resulted in severe growth retardation under the culture conditions used, with select ABC-transported carbohydrates (maltose, sorbitol, mannitol, cellobiose, trehalose, or mannose) used as the sole carbon source. Furthermore, we found that GlnR-mediated regulation of carbohydrate transport was highly conserved in actinomycetes. These results demonstrate that GlnR serves a role beyond nitrogen metabolism, mediating critical functions in carbon metabolism and crosstalk of nitrogen- and carbon-metabolism pathways in response to the nutritional states of cells. These findings provide insights into the molecular regulation of transport and metabolism of non-PTS carbohydrates and reveal potential applications for the cofermentation of biomass-derived sugars in the production of biofuels and bio-based chemicals. PMID:26644570

  11. Structural and Functional Characterizations of SsgB, a Conserved Activator of Developmental Cell Division in Morphologically Complex Actinomycetes

    SciTech Connect

    Xu, Qingping; Traag, Bjørn A.; Willemse, Joost; McMullan, Daniel; Miller, Mitchell D.; Elsliger, Marc-André; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Bakolitsa, Constantina; Carlton, Dennis; Chen, Connie; Chiu, Hsiu-Ju; Chruszcz, Maksymilian; Clayton, Thomas; Das, Debanu; Deller, Marc C.; Duan, Lian; Ellrott, Kyle; Ernst, Dustin; Farr, Carol L.; Feuerhelm, Julie; Grant, Joanna C.; Grzechnik, Anna; Grzechnik, Slawomir K.; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Kumar, Abhinav; Marciano, David; Minor, Wladek; Mommaas, A. Mieke; Morse, Andrew T.; Nigoghossian, Edward; Nopakun, Amanda; Okach, Linda; Oommachen, Silvya; Paulsen, Jessica; Puckett, Christina; Reyes, Ron; Rife, Christopher L.; Sefcovic, Natasha; Tien, Henry J.; Trame, Christine B.; van den Bedem, Henry; Wang, Shuren; Weekes, Dana; Hodgson, Keith O.; Wooley, John; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.; van Wezel, Gilles P.

    2010-01-20

    SsgA-like proteins (SALPs) are a family of homologous cell division-related proteins that occur exclusively in morphologically complex actinomycetes. We show that SsgB, a subfamily of SALPs, is the archetypal SALP that is functionally conserved in all sporulating actinomycetes. Sporulation-specific cell division of Streptomyces coelicolor ssgB mutants is restored by introduction of distant ssgB orthologues from other actinomycetes. Interestingly, the number of septa (and spores) of the complemented null mutants is dictated by the specific ssgB orthologue that is expressed. The crystal structure of the SsgB from Thermobifida fusca was determined at 2.6 {angstrom} resolution and represents the first structure for this family. The structure revealed similarities to a class of eukaryotic 'whirly' single-stranded DNA/RNA-binding proteins. However, the electro-negative surface of the SALPs suggests that neither SsgB nor any of the other SALPs are likely to interact with nucleotide substrates. Instead, we show that a conserved hydrophobic surface is likely to be important for SALP function and suggest that proteins are the likely binding partners.

  12. Nitrogen regulator GlnR controls uptake and utilization of non-phosphotransferase-system carbon sources in actinomycetes.

    PubMed

    Liao, Cheng-Heng; Yao, Lili; Xu, Ya; Liu, Wei-Bing; Zhou, Ying; Ye, Bang-Ce

    2015-12-22

    The regulatory mechanisms underlying the uptake and utilization of multiple types of carbohydrates in actinomycetes remain poorly understood. In this study, we show that GlnR (central regulator of nitrogen metabolism) serves as a universal regulator of nitrogen metabolism and plays an important, previously unknown role in controlling the transport of non-phosphotransferase-system (PTS) carbon sources in actinomycetes. It was observed that GlnR can directly interact with the promoters of most (13 of 20) carbohydrate ATP-binding cassette (ABC) transporter loci and can activate the transcription of these genes in response to nitrogen availability in industrial, erythromycin-producing Saccharopolyspora erythraea. Deletion of the glnR gene resulted in severe growth retardation under the culture conditions used, with select ABC-transported carbohydrates (maltose, sorbitol, mannitol, cellobiose, trehalose, or mannose) used as the sole carbon source. Furthermore, we found that GlnR-mediated regulation of carbohydrate transport was highly conserved in actinomycetes. These results demonstrate that GlnR serves a role beyond nitrogen metabolism, mediating critical functions in carbon metabolism and crosstalk of nitrogen- and carbon-metabolism pathways in response to the nutritional states of cells. These findings provide insights into the molecular regulation of transport and metabolism of non-PTS carbohydrates and reveal potential applications for the cofermentation of biomass-derived sugars in the production of biofuels and bio-based chemicals.

  13. Strain powered antennas

    NASA Astrophysics Data System (ADS)

    Domann, John P.; Carman, Greg P.

    2017-01-01

    This paper proposes the creation of strain powered antennas that radiate electromagnetic energy by mechanically vibrating a piezoelectric or piezomagnetic material. A closed form analytic model of electromagnetic radiation from a strain powered electrically small antenna is derived and analyzed. Fundamental scaling laws and the frequency dependence of strain powered antennas are discussed. The radiation efficiency of strain powered electrically small antennas is contrasted with a conventional electric dipole. Analytical results show that operating at the first mechanical resonance produces the most efficient strain powered radiation relative to electric dipole antennas. A resonant analysis is exploited to determine the material property space that produces efficient strain powered antennas. These results show how a properly designed strain powered antenna can radiate more efficiently than an equally sized electric dipole antenna.

  14. Genome Sequence and Analysis of the Soil Cellulolytic ActinomyceteThermobifida fusca

    SciTech Connect

    Lykidis, Athanasios; Mavromatis, Konstantinos; Ivanova, Natalia; Anderson, Iain; Land, Miriam; DiBartolo, Genevieve; Martinez, Michele; Lapidus, Alla; Lucas, Susan; Copeland, Alex; Richardson, Paul; Wilson,David B.; Kyrpides, Nikos

    2007-02-01

    Thermobifida fusca is a moderately thermophilic soilbacterium that belongs to Actinobacteria. 3 It is a major degrader ofplant cell walls and has been used as a model organism for the study of 4secreted, thermostable cellulases. The complete genome sequence showedthat T. fusca has a 5 single circular chromosome of 3642249 bp predictedto encode 3117 proteins and 65 RNA6 species with a coding densityof 85percent. Genome analysis revealed the existence of 29 putative 7glycoside hydrolases in addition to the previously identified cellulasesand xylanases. The 8 glycosyl hydrolases include enzymes predicted toexhibit mainly dextran/starch and xylan 9 degrading functions. T. fuscapossesses two protein secretion systems: the sec general secretion 10system and the twin-arginine translocation system. Several of thesecreted cellulases have 11 sequence signatures indicating theirsecretion may be mediated by the twin-arginine12 translocation system. T.fusca has extensive transport systems for import of carbohydrates 13coupled to transcriptional regulators controlling the expression of thetransporters and14 glycosylhydrolases. In addition to providing anoverview of the physiology of a soil 15 actinomycete, this study presentsinsights on the transcriptional regulation and secretion of16 cellulaseswhich may facilitate the industrial exploitation of thesesystems.

  15. Trehalose lipid biosurfactants produced by the actinomycetes Tsukamurella spumae and T. pseudospumae.

    PubMed

    Kügler, Johannes H; Muhle-Goll, Claudia; Kühl, Boris; Kraft, Axel; Heinzler, Raphael; Kirschhöfer, Frank; Henkel, Marius; Wray, Victor; Luy, Burkhard; Brenner-Weiss, Gerald; Lang, Siegmund; Syldatk, Christoph; Hausmann, Rudolf

    2014-11-01

    Actinomycetales are known to produce various secondary metabolites including products with surface-active and emulsifying properties known as biosurfactants. In this study, the nonpathogenic actinomycetes Tsukamurella spumae and Tsukamurella pseudospumae are described as producers of extracellular trehalose lipid biosurfactants when grown on sunflower oil or its main component glyceryltrioleate. Crude extracts of the trehalose lipids were purified using silica gel chromatography. The structure of the two trehalose lipid components (TL A and TL B) was elucidated using a combination of matrix-assisted laser desorption/ionization time-of-flight/time-of-flight/tandem mass spectroscopy (MALDI-ToF-ToF/MS/MS) and multidimensional NMR experiments. The biosurfactants were identified as 1-α-glucopyranosyl-1-α-glucopyranosid carrying two acyl chains varying of C4 to C6 and C16 to C18 at the 2' and 3' carbon atom of one sugar unit. The trehalose lipids produced demonstrate surface-active behavior and emulsifying capacity. Classified as risk group 1 organisms, T. spumae and T. pseudospumae hold potential for the production of environmentally friendly surfactants.

  16. Distribution, purification, and characterization of thermostable phenylalanine dehydrogenase from thermophilic actinomycetes.

    PubMed Central

    Ohshima, T; Takada, H; Yoshimura, T; Esaki, N; Soda, K

    1991-01-01

    Phenylalanine dehydrogenase (L-phenylalanine:NAD oxidoreductase, deaminating; EC 1.4.1.-) was found in various thermophilic actinomycetes. We purified the enzyme to homogeneity from Thermoactinomyces intermedius IFO 14230 by heat treatment and by Red Sepharose 4B, DEAE-Toyopearl, Sepharose CL-4B, and Sephadex G-100 chromatographies with a 13% yield. The relative molecular weight of the native enzyme was estimated to be about 270,000 by gel filtration. The enzyme consists of six subunits identical in molecular weight (41,000) and is highly thermostable: it is not inactivated by incubation at pH 7.2 and 70 degrees C for at least 60 min or in the range of pH 5 to 10.8 at 50 degrees C for 10 min. The enzyme preferably acts on L-phenylalanine and its 2-oxo analog, phenylpyruvate, in the presence of NAD and NADH, respectively. Initial velocity and product inhibition studies showed that the oxidative deamination proceeds through a sequential ordered binary-ternary mechanism. The Km values for L-phenylalanine, NAD, phenylpyruvate, NADH, and ammonia were 0.22, 0.078, 0.045, 0.025, and 106 mM, respectively. The pro-S hydrogen at C-4 of the dihydronicotinamide ring of NADH was exclusively transferred to the substrate. Images PMID:2061279

  17. Cyclodepsipeptides produced by actinomycetes inhibit cyclic-peptide-mediated quorum sensing in Gram-positive bacteria.

    PubMed

    Desouky, Said E; Shojima, Akane; Singh, Ravindra Pal; Matsufuji, Takahisa; Igarashi, Yasuhiro; Suzuki, Takashi; Yamagaki, Tohru; Okubo, Ken-Ichi; Ohtani, Kaori; Sonomoto, Kenji; Nakayama, Jiro

    2015-07-01

    Cyclic peptides are commonly used as quorum-sensing autoinducers in Gram-positive Firmicutes bacteria. Well-studied examples of such molecules are thiolactone and lactone, used to regulate the expression of a series of virulence genes in the agr system of Staphylococcus aureus and the fsr system of Enterococcus faecalis, respectively. Three cyclodepsipeptides WS9326A, WS9326B and cochinmicin II/III were identified as a result of screening actinomycetes culture extracts for activity against the agr/fsr system. These molecules are already known as receptor antagonists, the first two for tachykinin and the last one for endothelin. WS9326A also inhibited the transcription of pfoA regulated by the VirSR two-component system in Clostridium perfringens. Receptor-binding assays using a fluorescence-labeled autoinducer (FITC-GBAP) showed that WS9326A and WS9326B act as receptor antagonists in this system. In addition, an ex vivo assay showed that WS9326B substantially attenuated the toxicity of S. aureus for human corneal epithelial cells. These results suggest that these three natural cyclodepsipeptides have therapeutic potential for targeting the cyclic peptide-mediated quorum sensing of Gram-positive pathogens.

  18. Characterization of dusts collected from swine confinement buildings. [Verticillium sp. ; Actinomycetes

    SciTech Connect

    Donham, K.J.; Scallon, L.J.; Popendorf, W.; Treauhaft, M.W.; Roberts, R.D.

    1986-07-01

    The air in 21 different swine confinement buildings was sampled with 37 mm cassette filters with and without cyclone preselectors and with cascade impactors. Filter results yielded a mean total aerosol of 6.3 mg/m/sup 3/, a mean respirable aerosol of 0.5 mg/m/sup 3/; the geometric mean diameter was 2.9 microns. Cascade impactor measurements revealed a mean total aerosol of 7.6 mg/m/sup 3/, a respirable aerosol of 2.5 mg/m/sup 3/ and a mass median diameter of 9.6 microns. The two major constituents in these aerosols were grain particles and dried fecal matter. The grain particles were larger than fecal particles and proportionately more abundant in finishing buildings where 50 kg-100 kg animals are housed. Therefore the respirable fraction was less in finishing buildings than in farrowing and nursery buildings. Culturing of settled dusts yielded six different mold species, with the highest counts for Verticillium sp. (5 x 10/sup 2/ cfu/mg dry dust) grown at 37/sup 0/C. Thermophilic Actinomycetes and both gram negative and gram positive bacteria were isolated.

  19. Biogenic gold nanotriangles from Saccharomonospora sp., an endophytic actinomycetes of Azadirachta indica A. Juss.

    NASA Astrophysics Data System (ADS)

    Verma, Vijay C.; Anand, Swechha; Ulrichs, Christian; Singh, Santosh K.

    2013-04-01

    Microbial biofabrication is emerging as eco-friendly, simpler, and reproducible alternative to chemical synthesis of metals and semiconductor nanoparticles, allowing generation of rare geometrical forms such as nanotriangles and nanoprisms. Highly confined nanostructures like triangles/prisms are interesting class of nanoparticles due to their unique optical properties exploitable in biomedical diagnostics and biosensors. Here, we report for the first time a single-step biological protocol for the synthesis of gold nanotriangles using extract of endophytic actinomycetes Saccharomonospora sp., isolated from surface sterilized root tissues of Azadirachta indica A. Juss., when incubated with an aqueous solution of chloroaurate ions (AuCl- 4/1 mM). Thin, flat occasionally prismatic gold nanotriangles were produced when aqueous chloroaurate ions reacted with the cell-free extract as well as with the biomass of endophytic Saccharomonospora. It was evidenced from sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis that proteins of 42 and 50 kD were involved in biosynthesis as well as in stabilization of the nanoparticles. The particle growth process was monitored by UV-vis spectroscopy, and the morphological characterization was carried out by transmission electron microscopy and atomic force microscopy together with X-ray powder diffractions. Although the exact mechanism for this shape-oriented synthesis is not clear so far, the possibility of achieving nanoparticle shape control in a microbial system is exciting.

  20. Diversity of Ktedonobacteria with Actinomycetes-Like Morphology in Terrestrial Environments

    PubMed Central

    Yabe, Shuhei; Sakai, Yasuteru; Abe, Keietsu; Yokota, Akira

    2017-01-01

    Bacteria with an actinomycetes-like morphology have recently been discovered, and the class Ktedonobacteria was created for these bacteria in the phylum Chloroflexi. They may prove to be a valuable resource with the potential to produce unprecedented secondary metabolites. However, our understanding of their diversity, richness, habitat, and ecological significance is very limited. We herein developed a 16S rRNA gene-targeted, Ktedonobacteria-specific primer and analyzed ktedonobacterial amplicons. We investigated abundance, diversity, and community structure in forest and garden soils, sand, bark, geothermal sediment, and compost. Forest soils had the highest diversity among the samples tested (1181–2934 operational taxonomic units [OTUs]; Chao 1 estimate, 2503–5613; Shannon index, 4.21–6.42). A phylogenetic analysis of representative OTUs revealed at least eight groups within unclassified Ktedonobacterales, expanding the known diversity of this order. Ktedonobacterial communities markedly varied among our samples. The common mesic environments (soil, sand, and bark) were dominated by diverse phylotypes within the eight groups. In contrast, compost and geothermal sediment samples were dominated by known ktedonobacterial families (Thermosporotrichaceae and Thermogemmatisporaceae, respectively). The relative abundance of Ktedonobacteria in the communities, based on universal primers, was ≤0.8%, but was 12.9% in the geothermal sediment. These results suggest that unknown diverse Ktedonobacteria inhabit common environments including forests, gardens, and sand at low abundances, as well as extreme environments such as geothermal areas. PMID:28321007

  1. Cloning and characterization of the first actinomycete β-propeller phytase from Streptomyces sp. US42.

    PubMed

    Boukhris, Ines; Farhat-Khemakhem, Ameny; Bouchaala, Kameleddine; Virolle, Marie-Joëlle; Chouayekh, Hichem

    2016-10-01

    A gene encoding an extracellular phytase was cloned for the first time from an Actinomycete, Streptomyces sp. US42 and sequenced. The sequence of this gene revealed an encoded polypeptide (PHY US42) exhibiting one and six residues difference with the putative phytases of Streptomyces lividans TK24 and Streptomyces coelicolor A3(2), respectively. The molecular modeling of PHY US42 indicated that this phytase belongs to the group of β-propeller phytases that are usually calcium-dependent. PHY US42 was purified and characterized. Its activity was calcium-dependent and maximal at pH 7 and 65 °C. The enzyme was perfectly stable at pH ranging from 5 to 10 and its thermostability was greatly enhanced in the presence of calcium. Indeed, PHY US42 maintained 80% of activity after 10 min of incubation at 75 °C in the presence of 5 mM CaCl2 . PHY US42 was also found to exhibit high stability after incubation at 37 °C for 1 h in the presence of bovine bile and digestive proteases like of pepsin, trypsin, and chymotrypsin. Considering its biochemical properties, PHY US42 could be used as feed additive in combination with an acid phytase for monogastric animals.

  2. Field studies on two rock phosphate solubilizing actinomycete isolates as biofertilizer sources

    NASA Astrophysics Data System (ADS)

    Mba, Caroline C.

    1994-03-01

    Recently biotechnology is focusing attention on utilization of biological resources to solve a number of environmental problems such as soil fertility management. Results of microbial studies on earthworm compost in the University of Nigeria farm identified a number of rock phosphate solubilizing actinomycetes. Two of these, isclates 02 and 13, were found to be efficient rock phosphate (RP) solubilizers and fast-growing cellulolytic microbes producing extracellular hydrolase enzymes. In this preliminary field study the two microbial isolates were investigated with respect to their effects on the growth of soybean and egusi as well as their effect on the incidence of toxicity of poultry droppings. Application of these isolates in poultry manure-treated field plots, as microbial fertilizers, brought about yield increases of 43% and 17% with soybeans and 19% and 33% with egusi, respectively. Soil properties were also improved. With isolates 02 and 13, the soil available phosphorus increased at the five-leaf stage, while N-fixation in the soil increased by 45% or 11% relative to control. It was further observed that air-dried poultry manure after four days of incubation was still toxic to soybean. The toxic effect of the applied poultry manure was reduced or eliminated with microbial fertilizers 02 or 13, respectively. The beneficial effects of the microbial organic fertilizer are discussed. Justification for more intensive research on rock phosphate organic fertilizer is highlighted.

  3. 16S rRNA-based PCR-DGGE analysis of actinomycete communities in fields with continuous cotton cropping in Xinjiang, China.

    PubMed

    Zhang, Wei; Long, XuanQi; Huo, XiangDong; Chen, YiFeng; Lou, Kai

    2013-08-01

    The purpose of this study was to examine the variations in the microbial community structure of soil actinomycetes in fields with continuous cropping of cotton in Xinjiang Autonomous Region, China. Soil samples were collected from four depths in fields with 7-year continuous cotton cropping. The community structure of soil actinomycetes was examined using the 16S rRNA-based polymerase chain reaction-density gradient gel electrophoresis (PCR-DGGE) techniques. The microbial diversity indices of the soil samples from different depths generally decreased along with the period of continuous cotton cropping. When the period of continuous cropping of cotton reached 5 years, the diversity indices rose again and gradually stabilized at a level slightly lower than that of soils with original ecology (i.e., 0-year cotton cropping). Cluster analysis showed that at the 1-20-cm depth, the actinomycete community structure of the soil subjected to 1-year cotton cropping was similar to that of soil subjected to 0-year cotton cropping, whereas that of soils after 3-year continuous cotton cropping showed high similarity. At the 21-40-cm depth, the actinomycete community structure showed various changes but generally recovered to its original pattern after repeated fluctuations. Principal component analysis showed that at the 1-30-cm depth, the actinomycete community structure varied similarly regardless of the period of continuous cotton cropping. In contrast, there were no clear actinomycete community structure variation trends at the 31-40-cm soil depth. Homology comparison of sequences recovered from the DGGE bands showed that the obtained sequences shared similarities >88 %. Alignment with the known homologous sequences indicated a lack of microorganisms related to soil-borne cotton diseases. Continuous cotton cropping exerted significant influences on the community structure of soil actinomycetes in Xinjiang Autonomous Region, which were largely determined by the soil depth and

  4. Rapid identification of filamentous actinomycetes to the genus level using genus-specific 16S rRNA gene restriction fragment patterns.

    PubMed

    Cook, Andrew E; Meyers, Paul R

    2003-11-01

    A rapid method for identifying filamentous actinomycete genera was developed based on 16S rRNA gene restriction fragment patterns. The patterns were generated by using specific restriction endonucleases to perform in silico digestions on the 16S rRNA gene sequences of all validly published filamentous actinomycete species. The method was applied to identifying actinomycete isolates from soil. Amplified 16S rDNA of soil actinomycetes was restricted with selected endonucleases and electrophoresed on agarose gels. The restriction fragment patterns of the unknown isolates were easily compared to the established patterns. Significantly, the genus Streptomyces could be differentiated from all other actinomycete genera by using only four restriction endonucleases, Sau3AI, AsnI, KpnI and SphI. This could be achieved in a time period of as little as a week, following PCR-template DNA isolation by a simple method. The identification method allowed unknown, non-Streptomyces soil isolates to be identified to a genus or small subgroup of genera. The genera in these subgroups could, in some cases, be distinguished by virtue of colony-morphology differences.

  5. Non-radiative recombination in Ge{sub 1−y}Sn{sub y} light emitting diodes: The role of strain relaxation in tuned heterostructure designs

    SciTech Connect

    Gallagher, J. D.; Xu, C.; Smith, D. J.; Menéndez, J.; Senaratne, C. L.; Sims, P.; Kouvetakis, J.; Aoki, T.

    2015-06-28

    This paper describes the properties of Ge{sub 1−y}Sn{sub y} light emitting diodes with a broad range of Sn concentrations (y = 0.0–0.11). The devices are grown upon Si(100) platforms using ultra-low temperature deposition of highly reactive Ge and Sn hydrides. The device fabrication adopts two new photodiode designs which lead to optimized performance and enables a systematic study of the effects of strain relaxation on emission efficiency. In contrast with n-Ge/i-Ge{sub 1−y}Sn{sub y}/p-Ge analogs, which in most cases contain two defected interfaces, our designs include a p-layer with composition Ge{sub 1−z}Sn{sub z} chosen to be z < y to facilitate light extraction, but with z close enough to y to guarantee no strain relaxation at the i/p interface. In addition, a Ge{sub 1−x}Sn{sub x} alloy is also used for the n layer, with compositions in the 0 ≤ x ≤ y range, so that defected and non-defected n/i interfaces can be studied. The electroluminescence spectra vs the Sn content y in the intrinsic layer of the diodes exhibit a monotonic shift in the emission wavelength from 1550 nm to 2500 nm. On the other hand, the emission intensities show a complex dependence that cannot be explained solely on the basis of Sn concentrations. Detailed theoretical modeling of these intensities makes it possible to extract recombination lifetimes that are found to be more than three times longer in samples in which strain relaxation has not occurred at the n-i interface, demonstrating the existence of a large non-radiative contribution from the relaxation defects. This finding is particularly significant for direct gap diodes with y > 0.09, for which it is practically impossible to avoid strain relaxation in n-Ge/i-Ge{sub 1−y}Sn{sub y}/p-Ge analogs. The new designs introduced here open the door to the fabrication of highly efficient electrically pumped systems for applications in future generations of integrated photonics.

  6. Sprains and Strains

    MedlinePlus

    ... Typically, people with a strain experience pain, limited motion, muscle spasms, and possibly muscle weakness. They also ... program designed to prevent stiffness, improve range of motion, and restore the joint's normal flexibility and strength. ...

  7. Purification strategies, characteristics and thermodynamic analysis of a highly thermostable alkaline protease from a salt-tolerant alkaliphilic actinomycete, Nocardiopsis alba OK-5.

    PubMed

    Gohel, Sangeeta D; Singh, Satya P

    2012-03-15

    An alkaline protease from salt tolerant alkaliphilic actinomycetes, Nocardiopsis alba strain OK-5 was purified to homogeneity by 27 and 13 fold with a yield of 35 and 13% using two-steps and one-step method, respectively. The purification methods involved hydrophobic interaction on phenyl sapharose matrix. The apparent molecular mass was 20 kDa. The temperature optimum shifted from 70 to 80°C in 4M NaCl and 30% Na-glutamate, with significant stability at 60-80°C in Na-glutamate. Deactivation rate constant (K(d)) increased and half life (t(1/2)) decreased with the increasing temperatures from 37 to 80°C. The order of stability was: 30% Na-glutamate>4M NaCl>2M NaCl>0M NaCl. The enzyme was stable even at 80°C in 30% Na-glutamate with K(d) 4.11 and t(1/2) 168.64 min. The activation energies (E), enthalpy (ΔH*) and entropy (ΔS*) for protease deactivation in with Na-glutamate were 31.97 kJ/mole, 29.23 kJ/mole and -211.83 J/mole, respectively. The change in free energy (ΔG*) for protease deactivation at 60°C in 30% Na-glutamate was 101.70 kJ/mole. Protease had the highest activity and stability at pH 10-11. While the enzyme was highly resistant against chemical denaturation, it had varied responses to metal ions. Complete inhibition by PMSF confirmed serine nature of the protease. Na-glutamate, H(2)O(2), β-mercaptoethanol and different surfactants enhanced the activity.

  8. Design and Development of a Flexible Strain Sensor for Textile Structures Based on a Conductive Polymer Composite

    PubMed Central

    Cochrane, Cédric; Koncar, Vladan; Lewandowski, Maryline; Dufour, Claude

    2007-01-01

    The aim of this work is to develop a smart flexible sensor adapted to textile structures, able to measure their strain deformations. The sensors are “smart” because of their capacity to adapt to the specific mechanical properties of textile structures that are lightweight, highly flexible, stretchable, elastic, etc. Because of these properties, textile structures are continuously in movement and easily deformed, even under very low stresses. It is therefore important that the integration of a sensor does not modify their general behavior. The material used for the sensor is based on a thermoplastic elastomer (Evoprene)/carbon black nanoparticle composite, and presents general mechanical properties strongly compatible with the textile substrate. Two preparation techniques are investigated: the conventional melt-mixing process, and the solvent process which is found to be more adapted for this particular application. The preparation procedure is fully described, namely the optimization of the process in terms of filler concentration in which the percolation theory aspects have to be considered. The sensor is then integrated on a thin, lightweight Nylon fabric, and the electromechanical characterization is performed to demonstrate the adaptability and the correct functioning of the sensor as a strain gauge on the fabric. A normalized relative resistance is defined in order to characterize the electrical response of the sensor. Finally, the influence of environmental factors, such as temperature and atmospheric humidity, on the sensor performance is investigated. The results show that the sensor's electrical resistance is particularly affected by humidity. This behavior is discussed in terms of the sensitivity of the carbon black filler particles to the presence of water.

  9. Natural Strain

    NASA Technical Reports Server (NTRS)

    Freed, Alan D.

    1995-01-01

    The purpose of this paper is to present a consistent and thorough development of the strain and strain-rate measures affiliated with Hencky. Natural measures for strain and strain-rate, as I refer to them, are first expressed in terms of of the fundamental body-metric tensors of Lodge. These strain and strain-rate measures are mixed tensor fields. They are mapped from the body to space in both the Eulerian and Lagrangian configurations, and then transformed from general to Cartesian fields. There they are compared with the various strain and strain-rate measures found in the literature. A simple Cartesian description for Hencky strain-rate in the Lagrangian state is obtained.

  10. Geodermatophilus poikilotrophi sp. nov.: A Multitolerant Actinomycete Isolated from Dolomitic Marble

    PubMed Central

    Montero-Calasanz, Maria del Carmen; Hofner, Benjamin; Göker, Markus; Rohde, Manfred; Spröer, Cathrin; Hezbri, Karima; Gtari, Maher; Schumann, Peter; Klenk, Hans-Peter

    2014-01-01

    A novel Gram-reaction-positive, aerobic actinobacterium, tolerant to mitomycin C, heavy metals, metalloids, hydrogen peroxide, desiccation, and ionizing- and UV-radiation, designated G18T, was isolated from dolomitic marble collected from outcrops in Samara (Namibia). The growth range was 15–35°C, at pH 5.5–9.5 and in presence of 1% NaCl, forming greenish-black coloured colonies on GYM Streptomyces agar. Chemotaxonomic and molecular characteristics of the isolate matched those described for other representatives of the genus Geodermatophilus. The peptidoglycan contained meso-diaminopimelic acid as diagnostic diaminoacid. The main phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, and small amount of diphosphatidylglycerol. MK-9(H4) was the dominant menaquinone and galactose was detected as diagnostic sugar. The major cellular fatty acids were branched-chain saturated acids iso-C16:0 and iso-C15:0 and the unsaturated C17:1ω8c and C16:1ω7c. The 16S rRNA gene showed 97.4–99.1% sequence identity with the other representatives of genus Geodermatophilus. Based on phenotypic results and 16S rRNA gene sequence analysis, strain G18T is proposed to represent a novel species, Geodermatophilus poikilotrophi. Type strain is G18T (= DSM 44209T = CCUG 63018T). The INSDC accession number is HF970583. The novel R software package lethal was used to compute the lethal doses with confidence intervals resulting from tolerance experiments. PMID:25114928

  11. Use of dyes in solid medium for screening ligninolytic activity of selective actinomycetes

    SciTech Connect

    Chahal, D.S.; Kluepfel, D.; Morosoli, R.

    1995-12-31

    Lignin, a three-dimensional biopolymer, not only encrusts the cellulose microfibrils in a sheath-like manner, but is also bonded physically and chemically to the plant polysaccharides. Unless the lignin is depolymerized, solubilized, or removed, the cellulose and hemicelluloses cannot be easily hydrolyzed by respective enzymes for their bioconversion into biofuels and chemicals. By now it has been established that lignin peroxidase (LiP) of white-rot fungus Phanerochaete chrysosporium is responsible for degradation of lignin. It has been reported that LiP is produced during secondary metabolism under carbon or nitrogen limitation by this organism. In literature, usually low yields (per unit volume) of LiP with P. chrysosporium have been reported. The reasons for low yields may be attributed to insufficient nitrogen in production media, which ultimately affects the synthesis of LiP protein. Therefore, it necessitated a search for an organism that can produce a ligninolytic enzyme system during its primary metabolism, without any effect of nitrogen limitation in the fermentation medium and without supply of extra oxygen to the cultures. Glenn and Gold were the first to report that decolorization of polymeric dyes in liquid cultures is related to the lignin degradation system. They demonstrated that like lignin degradation, the decolorization of polymeric dyes by the white-rot basidiomycete P. chrysosporium occurred during secondary metabolism, was suppressed in cultures grown in the presence of high levels of nitrogen, and was strongly dependent on the oxygen concentration in the cultures. The present study was undertaken to establish if certain dyes in solid media could be used to screen ligninolytic activity of selective actinomycetes during their primary metabolism without the limitation of nitrogen in the medium.

  12. Domain Characterization of Cyclosporin Regio-Specific Hydroxylases in Rare Actinomycetes.

    PubMed

    Woo, Min-Woo; Lee, Bo-Ram; Nah, Hee-Ju; Choi, Si-Sun; Li, Shengying; Kim, Eung-Soo

    2015-10-01

    Cytochrome P450 hydroxylase (CYP) in actinomycetes plays an important role in the biosynthesis and bioconversion of various secondary metabolites. Two unique CYPs named CYP-sb21 and CYP-pa1, which were identified from Sebekia benihana and Pseudonocardia autotrophica, respectively, were proven to transfer a hydroxyl group at the 4(th) or 9(th) N-methyl leucine position of immunosuppressive agent cyclosporin A (CsA). Interestingly, these two homologous CYPs showed different CsA regio-selectivities. CYP-sb21 exhibited preferential hydroxylation activity at the 4(th) position over the 9(th) position, whereas CYP-pa1 showed the opposite preference. To narrow down the CYP domain critical for CsA regio-selectivity, each CYP was divided into four domains, and each domain was swapped with its counterpart from the other CYP. A total of 18 hybrid CYPs were then individually tested for CsA regioselectivity. Although most of the hybrid CYPs failed to exhibit a significant change in regioselectivity in the context of CsA hydroxylation, hybrid CYP-pa1 swapped with the second domain of CYP-sb21 showed a higher preference for the 9th position. Moreover, hybrid CYPsb21 containing seven amino acids from the 2nd domain of CYP-pa1 showed higher preference for the 4(th) position. These results imply that the 2nd domain of CsA-specific CYP plays a critical role in CsA regio-selectivity, thereby setting the stage for biotechnological application of CsA regio-selective hydroxylation.

  13. Thermodynamics of a Ca(2+)-dependent highly thermostable alkaline protease from a haloalkliphilic actinomycete.

    PubMed

    Gohel, S D; Singh, S P

    2015-01-01

    An alkaline protease from salt-tolerant alkaliphilic actinomycetes, Nocardiopsis alba OK-5 was purified by a single-step hydrophobic interaction chromatography and characterized. The purified protease with an estimated molecular mass of 20 kDa was optimally active at 70 °C in 0-3 M NaCl and 0-100 mM Ca(2+) displaying significant stability at 50-80 °C. The enzyme was stable at 80 °C in 100 mM Ca(2+) with Kd of 17 × 10(-3) and t1/2 of 32 min. The activation energy (Ea), enthalpy (ΔH*), and entropy (ΔS*) for the protease deactivation calculated in the presence of 200 mM Ca(2+) were 38.15 kJ/mol, 35.49 kJ/mol and 183.48 J/mol, respectively. The change in free energy (ΔG*) for protease deactivation at 60 °C in 200 mM Ca(2+) was 95.88 kJ/mol. Decrease in ΔH* reflected reduced cooperativity of deactivation and unfolding. The enzyme was intrinsically stable that counteracted heat denaturation by a weak cooperativity during the unfolding. Further, the enzyme was highly stable in the presence of various cations, surfactants, H2O2, β-mercaptoethanol, and commercial detergents. The compatibility of the enzyme with various cations, surfactants, and detergent matrices suggests its suitability as an additive in the detergents and peptide synthesis.

  14. Tartrolon D, a cytotoxic macrodiolide from the marine-derived actinomycete Streptomyces sp. MDG-04-17-069.

    PubMed

    Pérez, Marta; Crespo, Cristina; Schleissner, Carmen; Rodríguez, Pilar; Zúñiga, Paz; Reyes, Fernando

    2009-12-01

    Exploration of marine-derived actinomycetes as a source of antitumor compounds has led to the isolation of a new member of the tartrolon series, tartrolon D (4). This new compound was obtained from Streptomyces sp. MDG-04-17-069 fermentation broths and displayed strong cytotoxic activity against three human tumor cell lines. Additionally, the known compound ikarugamycin (5) was also found in the culture broths of the same microorganism. The structure of this new tartrolon was established by a combination of spectroscopic techniques (1D and 2D NMR, HRMS, and UV) as well as by comparison with published data for similar compounds.

  15. Cephamycins, a New Family of β-Lactam Antibiotics I. Production by Actinomycetes, Including Streptomyces lactamdurans sp. n1

    PubMed Central

    Stapley, E. O.; Jackson, M.; Hernandez, S.; Zimmerman, S. B.; Currie, S. A.; Mochales, S.; Mata, J. M.; Woodruff, H. B.; Hendlin, D.

    1972-01-01

    A number of actinomycetes isolated from soil were found to produce one or more members of a new family of antibiotics, the cephamycins, which are structurally related to cephalosporin C. The cephamycins were produced in submerged fermentation in a wide variety of media by one or more of eight different species of Streptomyces, including a newly described species, S. lactamdurans. These antibiotics exhibit antibacterial activity against a broad spectrum of bacteria which includes many that are resistant to the cephalosporins and penicillins. PMID:4790552

  16. An endophytic Streptomyces sp. strain DHV3-2 from diseased root as a potential biocontrol agent against Verticillium dahliae and growth elicitor in tomato (Solanum lycopersicum).

    PubMed

    Cao, Peng; Liu, Chongxi; Sun, Pengyu; Fu, Xuepeng; Wang, Shaoxian; Wu, Fengzhi; Wang, Xiangjing

    2016-12-01

    Plant endophytes play important roles in biocontrol of plant diseases. Actinomycetes are used for biocontrol of fungal diseases caused by Verticillium dahliae. Many studies have focused on the endophytic actinomycetes isolated from the roots of healthy plants, but few on those from the roots of diseased plants. In the present research, actinomycetes were isolated from the roots of diseased and healthy tomato plants, respectively. The results showed that, in total, 86 endophytic actinomycetes were isolated for screening of their antimicrobial activities, 8 of which showed antagonism to V. dahliae in vitro. Among the 8 antagonistic strains, 5 (out of 36) were from the roots of diseased plants, with inhibition diameter zones ranging from 11.2 to 18.2 mm, whereas 3 (out of 50) were from the roots of healthy plants, with inhibition diameter zones ranging from 11.5 to 15.5 mm. Endophytic strain DHV3-2 was isolated from the root of a diseased plant and demonstrated a potent effect against V. dahliae and other pathogenic fungi by showing the largest inhibition diameter zones among all the eight antagonistic strains. Thus, strain DHV3-2 was chosen to investigate its biological control efficacies in vivo. Further study showed that the disease incidence and disease severity indices of tomato Verticillium wilt decreased significantly (P < 0.05). We also found that the plant shoot fresh weight and height increased greatly (P < 0.05) upon treatment with strain DHV3-2 compared to the plants uninoculated in greenhouse conditions. Root colonization showed that strain DHV3-2 had the higher root-colonizing capacity in the roots of infected plants compared with the roots of healthy plants. This isolate was identified as Streptomyces sp. based on morphological characteristics and 16S rRNA gene analysis. In conclusion, the roots of diseased tomato plants are a potential reservoir of biological control actinomycetes, and Streptomyces sp. strain DHV3-2 is a potential biocontrol

  17. A Method for Calculating Strain Energy Release Rates in Preliminary Design of Composite Skin/Stringer Debonding Under Multi-Axial Loading

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald; Minguet, Pierre J.; OBrien, T. Kevin

    1999-01-01

    Three simple procedures were developed to determine strain energy release rates, G, in composite skin/stringer specimens for various combinations of unaxial and biaxial (in-plane/out-of-plane) loading conditions. These procedures may be used for parametric design studies in such a way that only a few finite element computations will be necessary for a study of many load combinations. The results were compared with mixed mode strain energy release rates calculated directly from nonlinear two-dimensional plane-strain finite element analyses using the virtual crack closure technique. The first procedure involved solving three unknown parameters needed to determine the energy release rates. Good agreement was obtained when the external loads were used in the expression derived. This superposition technique was only applicable if the structure exhibits a linear load/deflection behavior. Consequently, a second technique was derived which was applicable in the case of nonlinear load/deformation behavior. The technique involved calculating six unknown parameters from a set of six simultaneous linear equations with data from six nonlinear analyses to determine the energy release rates. This procedure was not time efficient, and hence, less appealing. A third procedure was developed to calculate mixed mode energy release rates as a function of delamination lengths. This procedure required only one nonlinear finite element analysis of the specimen with a single delamination length to obtain a reference solution for the energy release rates and the scale factors. The delamination was extended in three separate linear models of the local area in the vicinity of the delamination subjected to unit loads to obtain the distribution of G with delamination lengths. This set of sub-problems was Although additional modeling effort is required to create the sub- models, this local technique is efficient for parametric studies.

  18. Comparative Finite Element Analysis of the Stress-Strain States in Three Different Bonded Solid Oxide Fuel Cell Seal Designs

    SciTech Connect

    Weil, K. Scott; Koeppel, Brian J.

    2008-05-15

    One of the critical issues in designing and fabricating a high performance planar solid oxide fuel cell (pSOFC) stack is the development of the appropriate materials and techniques for hermetically sealing the metal and ceramic components. We are currently developing a foil-based approach that appears to offer good hermeticity and mechanical integrity, while minimizing the generation of interfacial stresses in either of the joint substrate materials, particulary the ceramic cell. Prior experimental work conducted on small-scale samples demonstrated the viability of the concept. Here we present recent results from computational analyses undertaken to investigate potential issues associated with scaling up the seal to full-scale pSOFC stack dimensions/geometry. Here we employ finite element modeling to assess the potential thermal cycling performance of this design, specifically as it pertains to sealing components with vastly different thermal expansion properties.

  19. Large-strain, multiform movements from designable electrothermal actuators based on large highly anisotropic carbon nanotube sheets.

    PubMed

    Li, Qingwei; Liu, Changhong; Lin, Yuan-Hua; Liu, Liang; Jiang, Kaili; Fan, Shoushan

    2015-01-27

    Many electroactive polymer (EAP) actuators use diverse configurations of carbon nanotubes (CNTs) as pliable electrodes to realize discontinuous, agile movements, for CNTs are conductive and flexible. However, the reported CNT-based EAP actuators could only accomplish simple, monotonous actions. Few actuators were extended to complex devices because efficiently preparing a large-area CNT electrode was difficult, and complex electrode design has not been carried out. In this work, we successfully prepared large-area CNT paper (buckypaper, BP) through an efficient approach. The BP is highly anisotropic, strong, and suitable as flexible electrodes. By means of artful graphic design and processing on BP, we fabricated various functional BP electrodes and developed a series of BP-polymer electrothermal actuators (ETAs). The prepared ETAs can realize various controllable movements, such as large-stain bending (>180°), helical curling (∼ 630°), or even bionic actuations (imitating human-hand actions). These functional and interesting movements benefit from flexible electrode design and the anisotropy of BP material. Owing to the advantages of low driving voltage (20-200 V), electrolyte-free and long service life (over 10000 times), we think the ETAs will have great potential applications in the actuator field.

  20. Screening of Rhizospheric Actinomycetes for Various In-vitro and In-vivo Plant Growth Promoting (PGP) Traits and for Agroactive Compounds

    PubMed Central

    Anwar, Sumaira; Ali, Basharat; Sajid, Imran

    2016-01-01

    In this study 98 rhizospheric actinomycetes were isolated from different wheat and tomato fields, Punjab, Pakistan. The isolates were characterized morphologically, biochemically, and genetically and were subjected to a comprehensive in vitro screening for various plant growth promoting (PGP) traits. About 30% of the isolates screened were found to be the promising PGP rhizobacteria (PGPRs), which exhibited maximum genetic similarity (up to 98–99%) with different species of the genus Streptomyces by using16S rRNA gene sequencing. The most active indole acetic acid (IAA) producer Streptomyces nobilis WA-3, Streptomyces Kunmingenesis WC-3, and Streptomyces enissocaesilis TA-3 produce 79.5, 79.23, and 69.26 μg/ml IAA respectively at 500 μg/ml L-tryptophan. The highest concentration of soluble phosphate was produced by Streptomyces sp. WA-1 (72.13 mg/100 ml) and S. djakartensis TB-4 (70.36 mg/100 ml). All rhizobacterial isolates were positive for siderophore, ammonia, and hydrogen cyanide production. Strain S. mutabilis WD-3 showed highest concentration of ACC-deaminase (1.9 mmol /l). For in-vivo screening, seed germination, and plant growth experiment were conducted by inoculating wheat (Triticum aestivum) seeds with the six selected isolates. Significant increases in shoot length was observed with S. nobilis WA-3 (65%), increased root length was recorded in case of S. nobilis WA-3 (81%) as compared to water treated control plants. Maximum increases in plant fresh weight were recorded with S. nobilis WA-3 (84%), increased plant dry weight was recorded in case of S. nobilis WA-3 (85%) as compared to water treated control plants. In case of number of leaves, significant increase was recorded with S. nobilis WA-3 (27%) and significant increase in case of number of roots were recorded in case of strain S. nobilis WA-3 (30%) as compared to control plants. Over all the study revealed that these rhizospheric PGP Streptomyces are good candidates to be developed as

  1. Moderating strain without sacrificing reactivity: design of fast and tunable noncatalyzed alkyne-azide cycloadditions via stereoelectronically controlled transition state stabilization.

    PubMed

    Gold, Brian; Dudley, Gregory B; Alabugin, Igor V

    2013-01-30

    Recently, we have identified two strategies for selective transition state (TS) stabilization in catalyst-free azide/alkyne cycloadditions. In particular, the transition states for the formation of both 1,4- and 1,5-isomers can be stabilized via hyperconjugative assistance for the C···N bond formation, whereas the 1,5-TS can be stabilized via C-H···X H-bonding interactions. When the hyperconjugative assistance is maximized by the antiperiplanar arrangement of propargylic σ-acceptors relative to the forming bonds, the combination of these TS-stabilizing effects was predicted to lead to ~1 million fold acceleration of the cycloaddition with methyl azide. The present work investigated whether hyperconjugative assistance and H-bonding can be combined with strain activation for the design of even more reactive alkynes and whether reactivity can be turned "on demand." When stereoelectronic amplification is achieved by optimal positioning of σ-acceptors at the endocyclic bonds antiperiplanar to the breaking alkyne π-bonds, the stabilization of the bent alkyne geometry leads to a significant decrease in strain in cyclic alkynes without compromising their reactivity in alkyne-azide cycloadditions. The approach can be used in a modular fashion where the TS stabilizing effects are introduced sequentially until the desired level of reactivity is achieved. A significant increase in reactivity upon the protonation of an endocyclic NH-group suggests a new strategy for the design of click reactions triggered by a pH-change or introduction of an external Lewis acid.

  2. Modelling, Design, Growth and Characterization of Strain Balanced Quantum Cascade Lasers (3-11mum), grown by Gas Source Molecular Beam Epitaxy

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Neelanjan

    Quantum Cascade Laser (QCL) is a compact room temperature (RT) source of mid-infrared radiation, which can be used for spectroscopic detection of trace amount of chemicals. The mid-infrared spectral range between (3-11 microm), has a dense array of absorption lines of numerous molecules, due to the presence of fundamental vibrational modes. The goal of this thesis can be subdivided into two parts. Firstly, short wavelength QCLs, emitting below 4microm, perform poorly at RT, due to inter-valley Gamma --- L carrier scattering, carrier escape to the continuum, heat removal from the core region at high power density corresponding to short wavelength operation, and large interface scattering due to highly strained materials. Secondly, it is desirable to have a single QCL based source emitting between 6-10microm, which be used to detect multiple molecules having their peak absorptions far apart, inside this spectral range. However, gain bandwidth of a single core QCL is relatively small, so laser emission cannot be tuned over a wide spectral range. This thesis describes the working principle of a QCL based on superlattice transport, rate equations, scattering mechanism, and waveguide design. The choice of the material system for this work and the fundamentals of band structure engineering has been derived. Gas source molecular beam epitaxy - growth optimization and characterization is one of the most important features of this work, especially for short wavelength QCLs, and has been explained in depth. Different strategies for design of active region design of short wavelength QCL and heterogeneous broadband QCL has been explored. The major milestones, of this research was the world's first watt level continuous wave (CW), RT demonstration at 3.76 microm, which was followed by another milestone of the first CW, RT demonstration at 3.39microm and 3.55microm, and finally the elusive result of QCL emitting at CW, RT at a wavelength as short as lambda ~3microm, a record. In

  3. Immunologic relatedness of extracellular ligninases from the actinomycetes Streptomyces viridosporus T7A and Streptomyces badius 252

    SciTech Connect

    Magnuson, T.S.; Roberts, M.A.; Crawford, D.L.; Hertel, G.

    1991-12-31

    Four isoforms of the extracellular lignin peroxidase of the ligninolytic actinomycete Streptomyces viridosporus T7A (ALip-P1, P2, P3, and P4) were individually purified by ultrafiltration and ammonium sulfate precipitation, followed by electro-elution using polyacrylamide gel electrophoresis. Three of the purified peroxidases were compared for their immunologic relatedness by Western blot analysis using a polyclonal antibody preparation produced in rabbits against pure isoform P3. The anti-P3 antibody was also tested for its reactivity towards a lignin peroxidase from the white-rot fungus Phanerochaete chrysosporium and another ligninolytic actinomycete Streptomyces badius 252. Results showed that peroxidases ALip-P1 through ALip-P3 are immunologically related to one another. The peroxidases of S. badius, but not the peroxidase of P. chrysosporium, also reacted with the antibody, thus indicating that the lignin peroxidases of S. viridosporus and S. badius are immunologically related. Based upon its specific affinity, fignin peroxidase isoform ALip-P3 of S. viridosporus was readily purified using an anti-P3 antibody affinity column.

  4. [Bergey's Manual of Systematic Bacteriology (second edition) Volume 5 and the study of Actinomycetes systematic in China].

    PubMed

    Ruan, Jisheng

    2013-06-04

    Bergey's Manual of Systematic Bacteriology (hereinafter referred to as "Bergey's Manual") is the collection of academic views accepted by taxonomists in many countries. It has scientificity, unitarity and practicality. "Bergey's Manual" (special issue of Actinomycetes) divided into two parts (part A and part B) was published in May, 2012. Under the guidance and the organization of Michael Goodfellow et al., the great work has been completed successfully in May 2012. "Bergey's Manual" made a great modification on the systematic of Actinomycetes and formally set up the phylum of Actinobacteria, which encompasses 6 classes, 23 orders (include one order incertae sides), 53 families, 222 genera and about 3000 species. The taxonomic catalogue is Bacteria, phylum of Actinobacteria, under the phylum there are class, order, family, genera and species. "Bergey's Manual" collected a great deal of new taxa, which were published in IJSEM (International Journal of Systematic and Evolutionary Microbiology) by Chinese scientists. We need to indicate that due to its too rigorous, conservative writing purpose and long publication periods, "Bergey's Manual" fails to collect new research results using the molecular approaches of multilocus sequence analysis "MLSA", gene chip technology and genome technologies, which however will profoundly change the taxonomy of prokaryotes in the near future.

  5. Effect of antibiotic down-regulatory gene wblA ortholog on antifungal polyene production in rare actinomycetes Pseudonocardia autotrophica.

    PubMed

    Kim, Hye-Jin; Kim, Min-Kyung; Jin, Ying-Yu; Kim, Young-Woo; Kim, Eung-Soo

    2014-09-01

    The rare actinomycete Pseudonocardia autotrophica was previously shown to produce a solubilityimproved toxicity-reduced novel polyene compound named Nystatin-like Pseudonocardia Polyene (NPP). The low productivity of NPP in P. autotrophica implies that its biosynthetic pathway is tightly regulated. In this study, wblApau was isolated and identified as a novel negative regulatory gene for NPP production in P. autotrophica, which showed approximately 49% amino acid identity with a global antibiotic down-regulatory gene, wblA, identified from various Streptomycetes species. Although no significant difference in NPP production was observed between P. autotrophica harboring empty vector and the S. coelicolor wblA under its native promoter, approximately 12% less NPP was produced in P. autotrophica expressing the wblA gene under the strong constitutive ermE(*) promoter. Furthermore, disruption of the wblApau gene from P. autotrophica resulted in an approximately 80% increase in NPP productivity. These results strongly suggest that identification and inactivation of the global antibiotic down-regulatory gene wblA ortholog are a critical strategy for improving secondary metabolite overproduction in not only Streptomyces but also non-Streptomyces rare actinomycete species.

  6. Distribution of live and dead cells in pellets of an actinomycete Amycolatopsis balhimycina and its correlation with balhimycin productivity.

    PubMed

    Singh, Kamaleshwar P; Mahendra, Amit L; Jayaraj, Vibha; Wangikar, Pramod P; Jadhav, Sameer

    2013-02-01

    Secondary metabolites such as antibiotics are typically produced by actinomycetes as a response to growth limiting stress conditions. Several studies have shown that secondary metabolite production is correlated with changes observed in actinomycete pellet morphology. Therefore, we investigated the correlation between the production of balhimycin and the spatio-temporal distribution of live and dead cells in pellets of Amycolatopsis balhimycina in submerged cultures. To this end, we used laser scanning confocal microscopy to analyze pellets from balhimycin producing and nonproducing media containing 0.2 and 1.0 g l(-1) of potassium di-hydrogen phosphate, respectively. We observed a substantially higher fraction of live cells in pellets from cultures yielding larger amounts of balhimycin. Moreover, in media that resulted in no balhimycin production, the pellets exhibit an initial death phase which commences from the centre of the pellet and extends in the radial direction. A second growth phase was observed in these pellets, where live mycelia are seen to appear in the dead core of the pellets. This secondary growth was absent in pellets from media producing higher amounts of balhimycin. These results suggest that distribution of live and dead cells and its correlation with antibiotic production in the non-sporulating A. balhimycina differs markedly than that observed in Streptomycetes.

  7. Intradermal application of Aujeszky's disease virus strain Begonia with tocopherol-based adjuvant and a novel design injection device.

    PubMed

    Visser, N; Egger, W; Lütticken, D

    1994-01-01

    Initially the use of intradermal application of Aujeszky's disease vaccines was shown to be very effective. However, for thus far unknown reasons the gI-deleted vaccines were much less efficacious by using this route of vaccination as compared to gI-positive vaccines. By the use of a tocopherol-based adjuvant and an improved design of the intradermal injection device it now appeared feasible to obtain the same efficacy both in specific pathogen free pigs and in pigs with material antibodies as found before when intramuscular administration was performed. With respect to safety we found a complete lack of skin lesions, no adverse systemic reactions (e.g. body temperatures) and no effect on growth rates. Last but not least, the easiness of intradermal injections is of great advantage in large-scale vaccination programs.

  8. Characterization of protein and mannan polysaccharide antigens of yeasts, moulds, and actinomycetes.

    PubMed

    Reiss, E; Huppert, M; Cherniak, R

    1985-01-01

    detecting mannan in serum. MAbs against the partially purified "m" factor of histoplasmin were characterized by the enzyme-linked immunoelectro-transfer blot technique (EITB), revealing unsuspected complexity in the antigen. Secreted proteins of Nocardia asteroides were isoelectrically focused; three proteins, identified by EITB as promising to be specific for that actinomycete, were cut out of gels and used to immunize mice for production of MAbs. The fimbriae of Actinomyces viscosus and A. naeslundii that mediate lactose-reversible coagglutination with Streptococcus sanguis have been used to evoke MAbs.(ABSTRACT TRUNCATED AT 400 WORDS)

  9. Vehicular Causation Factors and Conceptual Design Modifications to Reduce Aortic Strain in Numerically Reconstructed Real World Nearside Lateral Automotive Crashes

    PubMed Central

    Belwadi, Aditya; Yang, King H.

    2015-01-01

    Aortic injury (AI) leading to disruption of the aorta is an uncommon but highly lethal consequence of trauma in modern society. Most recent estimates range from 7,500 to 8,000 cases per year from a variety of causes. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest cavity. It is evident that effective means of substantially improving the outcome of motor vehicle crash-induced AIs is by preventing the injury in the first place. In the current study, 16 design of computer experiments (DOCE) were carried out with varying levels of principal direction of force (PDOF), impact velocity, impact height, and impact position of the bullet vehicle combined with occupant seating positions in the case vehicle to determine the effects of these factors on aortic injury. Further, a combination of real world crash data reported in the Crash Injury Research and Engineering Network (CIREN) database, Finite Element (FE) vehicle models, and the Wayne State Human Body Model-II (WSHBM-II) indicates that occupant seating position, impact height, and PDOF, in that order play, a primary role in aortic injury. PMID:26448781

  10. Thin film strain transducer

    NASA Astrophysics Data System (ADS)

    Rand, J. L.

    1981-01-01

    Previous attempts to develop an appropriate sensor for measuring the stress or strain of high altitude balloons during flight are reviewed as well as the various conditions that must be met by such a device. The design, development and calibration of a transducer which promises to satisfy the necessary design constraints are described. The thin film strain transducer has a low effective modulus so as not to interfere with the strain that would naturally occur in the balloon. In addition, the transducer has a high sensitivity to longitudinal strain (7.216 mV/V/unit strain) which is constant for all temperature from room temperature to -80 C and all strains from 5 percent compression to 10 percent tensile strain. At the same time, the sensor is relatively insensitive (0.27 percent) to transverse forces. The device has a standard 350 ohm impedance which is compatible with available bridge balance, amplification and telemetry instrumentation now available for balloon flight. Recommendations are included for improved coatings to provide passive thermal control as well as model, tethered and full scale flight testing.

  11. Non-linear visco-elastic analysis and the design of super-pressure balloons : stress, strain and stability

    NASA Astrophysics Data System (ADS)

    Wakefield, David

    Tensys have a long-established background in the shape generation and load analysis of architectural stressed membrane structures. Founded upon their inTENS finite element analysis suite, these activities have broadened to encompass ‘lighter than air' structures such as aerostats, hybrid air-vehicles and stratospheric balloons. Since 2004 Tensys have acted as consultants to the NASA Ultra Long Duration Balloon (ULDB) Program. Early implementations of the super-pressure balloon design chosen for ULDB have shown problems of geometric instability, characterised by improper deployment and the potential for overall geometric instability once deployed. The latter has been reproduced numerically using inTENS, and the former are better understood following a series of large-scale hangar tests simulating launch and ascent. In both cases the solution lies in minimising the film lobing between the tendons. These tendons, which span between base and apex end fittings, cause the characteristic pumpkin shape of the balloons and also provide valuable constraint against excessive film deformation. There is also the requirement to generate a biaxial stress field in order to mobilise in-plane shear stiffness. A consequence of reduced lobing between tendons is the development of higher stresses in the balloon film under pressure. The different thermal characteristics between tendons and film lead to further significant meridional stress under low temperature flight conditions. The non-linear viscoelastic response of the envelope film acts positively to help dissipate excessive stress and local concentrations. However, creep over time may produce lobe geometry variations sufficient to compromise the geometric stability of the balloon. The design of a balloon requires an analysis approach that addresses the questions of stress and stability over the duration of a flight by time stepping analyses using an appropriate material model. This paper summarises the Dynamic Relaxation

  12. Isolation, identification and characterization of a novel Rhodococcus sp. strain in biodegradation of tetrahydrofuran and its medium optimization using sequential statistics-based experimental designs.

    PubMed

    Yao, Yanlai; Lv, Zhenmei; Min, Hang; Lv, Zhenhua; Jiao, Huipeng

    2009-06-01

    Statistics-based experimental designs were applied to optimize the culture conditions for tetrahydrofuran (THF) degradation by a newly isolated Rhodococcus sp. YYL that tolerates high THF concentrations. Single factor experiments were undertaken for determining the optimum range of each of four factors (initial pH and concentrations of K(2)HPO(4).3H(2)O, NH(4)Cl and yeast extract) and these factors were subsequently optimized using the response surface methodology. The Plackett-Burman design was used to identify three trace elements (Mg(2+), Zn(2+)and Fe(2+)) that significantly increased the THF degradation rate. The optimum conditions were found to be: 1.80 g/L NH(4)Cl, 0.81 g/L K(2)HPO(4).3H(2)O, 0.06 g/L yeast extract, 0.40 g/L MgSO(4).7H(2)O, 0.006 g/L ZnSO(4).7H(2)O, 0.024 g/L FeSO(4).7H(2)O, and an initial pH of 8.26. Under these optimized conditions, the maximum THF degradation rate increased to 137.60 mg THF h(-1) g dry weight in Rhodococcus sp. YYL, which was nearly five times of that by the previously described THF degrading Rhodococcus strain.

  13. Design of Indigenous ELISA Using Tachyzoites from the RH Strain of Toxoplasma gondii and Comparison with Commercial Kits in Ahvaz, Southwest of Iran, 2015

    PubMed Central

    Mohammadpour, Niloofar; Saki, Jasem; Rafiei, Abdollah; Khodadadi, Ali; Tavalla, Mehdi; Cheraghian, Bahman

    2016-01-01

    Background Toxoplasma gondii is one of the most common causes of latent infections in humans worldwide. Detecting anti-Toxoplasma antibodies in serum using serological tests is a common method to diagnose toxoplasmosis. Objectives In the present study, an indigenous ELISA kit was prepared using tachyzoites from the RH strain of T. gondii, and its sensitivity and specificity were compared with those of commercial kits. Methods To produce antigens, 0.02 mL of locally isolated T. gondii RH strain parasites along with 109 tachyzoites were injected into the peritoneal cavities of 50 laboratory mice (BALB/C). Parasites were collected after 4 days. After filtering and washing, the concentration of protein in sonicated tachyzoites was calculated using the Lowry protein assay. The dilution of antigen, serum and alkaline phosphatase conjugate was assessed in designing an indigenous ELISA method; then ELISA was performed based on these dilutions, and its sensitivity was determined using 200 serum samples. In addition, the specificity of the assay was evaluated using 40 serum samples from patients with tuberculosis, leukemia or hydatid cyst. Results Indigenous ELISA was used to examine 100 serum samples containing anti-T. gondii IgG, with a sensitivity of 98% (commercial kits: 100%). Another 100 serum samples containing anti-T. gondii IgM were also tested, with a sensitivity of 99% (commercial kits: 100%). When 40 serum samples from patients with leukemia, hydatid cyst or tuberculosis were examined using anti-T. gondii IgG, the specificity was 100%, identical to commercial kits. However, the specificity of a similar test with anti-T. gondii IgM was just 28.6% for serum samples from leukemia patients, 21.4% for hydatid cyst and 16.7% for tuberculosis. Conclusions We found that purified locally isolated soluble crude antigens of the RH strain of T. gondii from the peritoneal cavity of mice may be one of the most promising antigens for detection of human toxoplasmosis in routine

  14. Isolation, abundance and phylogenetic affiliation of endophytic actinomycetes associated with medicinal plants and screening for their in vitro antimicrobial biosynthetic potential

    PubMed Central

    Passari, Ajit K.; Mishra, Vineet K.; Saikia, Ratul; Gupta, Vijai K.; Singh, Bhim P.

    2015-01-01

    Microorganisms associated with medicinal plants are of interest as the producers of important bioactive compounds. To date, the diversity of culturable endophytic actinomycetes associated with medicinal plants is in its initial phase of exploration. In this study, 42 endophytic actinomycetes were isolated from different organs of seven selected medicinal plants. The highest number of isolates (n = 22, 52.3%) of actinomycetes was isolated from roots, followed by stems (n = 9, 21.4%), leaves (n = 6, 14.2%), flowers (n = 3, 7.1%), and petioles (n = 2, 4.7%). The genus Streptomyces was the most dominant among the isolates (66.6%) in both the locations (Dampa TRF and Phawngpuii NP, Mizoram, India). From a total of 42 isolates, 22 isolates were selected for further studies based on their ability to inhibit one of the tested human bacterial or fungal pathogen. Selected isolates were identified based on 16S rRNA gene analysis and subsequently the isolates were grouped to four different genera; Streptomyces, Brevibacterium, Microbacterium, and Leifsonia. Antibiotic sensitivity assay was performed to understand the responsible antimicrobials present in the isolates showing the antimicrobial activities and revealed that the isolates were mostly resistant to penicillin G and ampicillin. Further, antimicrobial properties and antibiotic sensitivity assay in combination with the results of amplification of biosynthetic genes polyketide synthase (PKS-I) and non-ribosomal peptide synthetase (NRPS) showed that the endophytic actinomycetes associated with the selected medicinal plants have broad-spectrum antimicrobial activity. This is the first report of the isolation of Brevibacterium sp., Microbacterium sp., and Leifsonia xyli from endophytic environments of medicinal plants, Mirabilis jalapa and Clerodendrum colebrookianum. Our results emphasize that endophytic actinomycetes associated with medicinal plants are an unexplored resource for the discovery of biologically active

  15. Strain Gage

    NASA Technical Reports Server (NTRS)

    1995-01-01

    HITEC Corporation developed a strain gage application for DanteII, a mobile robot developed for NASA. The gage measured bending forces on the robot's legs and warned human controllers when acceptable forces were exceeded. HITEC further developed the technology for strain gage services in creating transducers out of "Indy" racing car suspension pushrods, NASCAR suspension components and components used in motion control.

  16. The Mitochondrial Toxin Produced by Streptomyces griseus Strains Isolated from an Indoor Environment Is Valinomycin

    PubMed Central

    Andersson, M. A.; Mikkola, R.; Kroppenstedt, R. M.; Rainey, F. A.; Peltola, J.; Helin, J.; Sivonen, K.; Salkinoja-Salonen, M. S.

    1998-01-01

    Actinomycete isolates from indoor air and dust in water-damaged schools and children’s day care centers were tested for toxicity by using boar spermatozoa as an indicator. Toxicity was detected in extracts of four strains which caused a loss of sperm motility, and the 50% effective concentrations (EC50) were 10 to 63 ng (dry weight) ml of extended boar semen−1. The four strains were identified as Streptomyces griseus strains by 16S ribosomal DNA and chemotaxonomic methods. The four S. griseus strains had similar effects on sperm cells, including loss of motility and swelling of mitochondria, but we observed no loss of plasma membrane integrity or depletion of cellular ATP. None of the effects was observed with sperm cells exposed to extracts of other indoor actinomycete isolates at concentrations of ≥5,000 to 72,000 ng ml−1. The toxin was purified from all four strains and was identified as a dodecadepsipeptide, and the fragmentation pattern obtained by tandem mass spectrometry was identical to that of valinomycin. Commercial valinomycin had effects in sperm cells that were identical to the effects of the four indoor isolates of S. griseus. The EC50 of purified toxin from the S. griseus strains were 1 to 3 ng ml of extended boar semen−1, and the EC50 of commercial valinomycin was 2 ng ml of extended boar semen−1. To our knowledge, this is the first report of the presence of ionophoric toxin producers in an indoor environment and the first report of valinomycin-producing strains identified as S. griseus. PMID:9835560

  17. The macrolide-lincosamide-streptogramin B resistance phenotypes characterized by using a specifically deleted, antibiotic-sensitive strain of Streptomyces lividans.

    PubMed Central

    Pernodet, J L; Fish, S; Blondelet-Rouault, M H; Cundliffe, E

    1996-01-01

    Genes conferring resistance to macrolide, lincosamide, and streptogramin B (MLS) antibiotics via ribosomal modification are widespread in bacteria, including clinical isolates and MLS-producing actinomycetes. Such erm-type genes encode enzymes that mono- or dimethylate residue A-2058 of 23S rRNA. The different phenotypes resulting from monomethylation (MLS-I phenotype, conferred by erm type I genes) or dimethylation (MLS-II phenotype due to erm type II genes) have been characterized by introducing tlrD or ermE, respectively, into an MLS-sensitive derivative of Streptomyces lividans TK21. This strain (designated OS456) was generated by specific replacement of the endogenous resistance genes lrm and mgt. The MLS-I phenotype is characterized by high-level resistance to lincomycin with only marginal resistance to macrolides such as chalcomycin or tylosin, whereas the MLS-II phenotype involves high-level resistance to all MLS drugs. Mono- and dimethylated ribosomes were introduced into a cell-free protein-synthesizing system prepared from S. lividans and compared with unmodified particles in their response to antibiotics. There was no simple correlation between the relative potencies of MLS drugs at the level of the target site (i.e., the ribosome) and their antibacterial activities expressed as MICs. PMID:8851574

  18. The macrolide-lincosamide-streptogramin B resistance phenotypes characterized by using a specifically deleted, antibiotic-sensitive strain of Streptomyces lividans.

    PubMed

    Pernodet, J L; Fish, S; Blondelet-Rouault, M H; Cundliffe, E

    1996-03-01

    Genes conferring resistance to macrolide, lincosamide, and streptogramin B (MLS) antibiotics via ribosomal modification are widespread in bacteria, including clinical isolates and MLS-producing actinomycetes. Such erm-type genes encode enzymes that mono- or dimethylate residue A-2058 of 23S rRNA. The different phenotypes resulting from monomethylation (MLS-I phenotype, conferred by erm type I genes) or dimethylation (MLS-II phenotype due to erm type II genes) have been characterized by introducing tlrD or ermE, respectively, into an MLS-sensitive derivative of Streptomyces lividans TK21. This strain (designated OS456) was generated by specific replacement of the endogenous resistance genes lrm and mgt. The MLS-I phenotype is characterized by high-level resistance to lincomycin with only marginal resistance to macrolides such as chalcomycin or tylosin, whereas the MLS-II phenotype involves high-level resistance to all MLS drugs. Mono- and dimethylated ribosomes were introduced into a cell-free protein-synthesizing system prepared from S. lividans and compared with unmodified particles in their response to antibiotics. There was no simple correlation between the relative potencies of MLS drugs at the level of the target site (i.e., the ribosome) and their antibacterial activities expressed as MICs.

  19. Paper Mill Effluent Decolorization by Fifty Streptomyces Strains

    PubMed Central

    Hernández, Manuel; Rodríguez, Juana; Soliveri, Juan; Copa, José L.; Pérez, María I.; Arias, María E.

    1994-01-01

    Fifty actinomycete strains isolated from lignocellulosic substrates were examined for the ability to remove the color from a paper mill effluent obtained after semichemical alkaline pulping of wheat straw. Streptomyces sp. strains UAH 15, UAH 23, UAH 30, and UAH 51 were selected for their ability to decolorize the effluent in a liquid medium containing 1% (wt/vol) glycerol, 0.2% (wt/vol) ammonium sulfate, and 80% (vol/vol) effluent. The highest levels of decolorization achieved after the strains grew were 60 to 65%. Strains UAH 30 and UAH 51 were selected for further study because of their different patterns of effluent decolorization during growth. Fractionation of the decolorized effluent by gel permeation chromatography demonstrated that there were reductions in the levels of absorbance of the high- and medium-molecular-weight compounds. These fractions were mainly responsible for the color of the effluent, while the last fractions, the low-molecular-weight compounds, could have been responsible for the residual color of the decolorized effluent. Thin-layer chromatography revealed significant differences among the patterns of bands corresponding to the acidified supernatants obtained after precipitation of alkali-lignin from the effluent samples decolorized by different Streptomyces strains. Images PMID:16349426

  20. Rhodococcus canchipurensis sp. nov., an actinomycete isolated from a limestone deposit site.

    PubMed

    Nimaichand, Salam; Sanasam, Suchitra; Zheng, Liu-Qiang; Zhu, Wen-Yong; Yang, Ling-Ling; Tang, Shu-Kun; Ningthoujam, Debananda S; Li, Wen-Jun

    2013-01-01

    A novel actinobacterial strain, MBRL 353(T), was isolated from a sample collected from a limestone quarry at Hundung, Manipur, India. Comparison of 16S rRNA gene sequences of strain MBRL 353(T) and other members of the genus Rhodococcus showed sequence similarities ranging from 95.5 to 98.2 %, with strain MBRL 353(T) showing closest sequence similarity to Rhodococcus triatomae IMMIB RIV-085(T) (98.2 %) and Rhodococcus equi DSM 20307(T) (97.2 %). DNA-DNA hybridization results, however, revealed that DNA-DNA relatedness values between strain MBRL 353(T) and R. triatomae DSM 44892(T) (43.4 %) and R. equi DSM 20307(T) (33.4 %) were well below the 70 % limit for species identification. Strain MBRL 353(T) contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose and arabinose in the cell wall. Mycolic acids were present. The major fatty acids were C(16 : 0) (45.7 %), C(18 : 1)ω9c (18.2 %) and 10-methyl C(18 : 0) (11.3 %). The only menaquinone detected was MK-8(H(2)), while the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and one unknown phospholipid. The G+C content of the genomic DNA was 69.2 mol%. The phenotypic and genotypic data showed that strain MBRL 353(T) merits recognition as a representative of a novel species of the genus Rhodococcus for which the name Rhodococcus canchipurensis sp. nov. is proposed; the type strain is MBRL 353(T) (= KCTC 19851(T) = JCM 17578(T)).

  1. Phylogenomic analysis of polyketide synthase genes in actinomycetes: structural analysis of KS domains and modules of polyketide synthases.

    PubMed

    Sarwar, Samreen; Ahmed, Mehboob; Hasnain, Shahida

    2012-01-01

    Polyketides are complex and diverse secondary metabolites, synthesised by large multifunctional enzymes, Polyketide Synthases (PKS). The phylogenomic analysis of β-ketosynthase (KS) domains and PKSs within actinomycetes suggests the contribution of point mutations, gene duplications, horizontal gene transfer and homologous recombination in the evolution of PKSs. PKS genealogy suggested the ancestral module structure with KS-AT-ACP domain composition. KS domains showed similar core and highly variable loop regions at the dimer interface, which seems to affect the selectivity of the primer unit. In PKS modules, the linker regions comprise a significant fraction of the module. The reducing domains (ketoreductase and dehydrogenase) protrude out from the central axis of the module and also responsible for extreme variability in the final products. Thus, phylogenomic and structural analysis of PKSs can assist in the artificial reprogramming of PKSs.

  2. Achieving high performance electric field induced strain: a rational design of hyperbranched aromatic polyamide functionalized graphene-polyurethane dielectric elastomer composites.

    PubMed

    Chen, Tian; Qiu, Jinhao; Zhu, Kongjun; Li, Jinhuan; Wang, Jingwen; Li, Shuqin; Wang, Xiaoliang

    2015-03-26

    Dielectric elastomers have great potentials as flexible actuators in micro-electromechanical systems (MEMS) due to their large deformation, light weight, mechanical compliancy, and low cost. The low dielectric constant of these elastomers requires a rather high voltage electric field, which has greatly limited their applications. In this work, a diaphragm-type flexible microactuator comprising a hyperbranched aromatic polyamide functionalized graphene (HAPFG) filler embedded into the polyurethane (PU) dielectric elastomer matrix is described. The rational designed HAPFG sheets exhibits uniform dispersion in PU matrix and strong adhesion with the matrix by hydrogen-bond coupling. Consequently, the HAPFG-PU composites possess high dielectric performance and low loss modulus. The effect of hyperbranched aromatic polyamide functionalized graphene on high voltage electric field induced strain was experimentally investigated using the Fotonic sensor. The high electric field response of the composite was discussed by applying different kinds of alternating-current field. In addition, a comparison of the breakdown strength between the HAPFG-PU composite and the pure PU was carried out.

  3. Degradation and induction specificity in actinomycetes that degrade p-nitrophenol

    SciTech Connect

    Hanne, L.F.; Kirk, L.L.; Appel, S.M.; Narayan, A.D.; Bains, K.K. )

    1993-10-01

    We have isolated two soil bacteria (identified as Arthrobacter aurescens TW17 and Nocardia sp. strain TW2) capable of degrading p-nitrophenol (PNP) and numerous other phenolic compounds. A. aurescens TW17 contains a large plasmid which correlated with the PNP degradation phenotype. Degradation of PNP by A. aurescens TW 17 was induced by preexposure to PNP, 4-nitrocatechol, 3-methyl-4-nitrophenol, or m-nitrophenol, whereas PNP degradation by Nocardia sp. strain TW2 was induced by PNP, 4-nitrocatechol, phenol, p-cresol, or m-nitrophenol. A. aurescens TW17 initially degraded PNP to hydroquinone and nitrite. Nocardia sp. strain TW2 initially converted PNP to hydroquinone or 4-nitrocatechol, depending upon the inducing compound.

  4. Strain isolated ceramic coatings

    NASA Technical Reports Server (NTRS)

    Tolokan, R. P.; Brady, J. B.; Jarrabet, G. P.

    1985-01-01

    Plasma sprayed ceramic coatings are used in gas turbine engines to improve component temperature capability and cooling air efficiency. A compliant metal fiber strain isolator between a plasma sprayed ceramic coating and a metal substrate improves ceramic durability while allowing thicker coatings for better insulation. Development of strain isolated coatings has concentrated on design and fabrication of coatings and coating evaluation via thermal shock testing. In thermal shock testing, five types of failure are possible: buckling failure im compression on heat up, bimetal type failure, isothermal expansion mismatch failure, mudflat cracking during cool down, and long term fatigue. A primary failure mode for thermally cycled coatings is designated bimetal type failure. Bimetal failure is tensile failure in the ceramic near the ceramic-metal interface. One of the significant benefits of the strain isolator is an insulating layer protecting the metal substrate from heat deformation and thereby preventing bimetal type failure.

  5. Geomechanical Modeling of CO2 Injection Site to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Sobolik, S. R.; Gomez, S. P.; Matteo, E. N.; Stormont, J.

    2014-12-01

    This paper will present the results of large-scale three-dimensional calculations simulating the hydrological-mechanical behavior of a CO2injection reservoir and the resulting effects on wellbore casings and sealant repair materials. A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. The DOE-NETL project "Wellbore Seal Repair Using Nanocomposite Materials," is interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Two distinct computational models comprise the current modeling effort. The first is a field scale model that uses the stratigraphy, material properties, and injection history from a pilot CO2injection operation in Cranfield, MS to develop a stress-strain history for wellbore locations from 100 to 400 meters from an injection well. The results from the field scale model are used as input to a more detailed model of a wellbore casing. The 3D wellbore model examines the impacts of various loading scenarios on a casing structure. This model has been developed in conjunction with bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. The results from these models will be used to estimate the necessary mechanical properties needed for a successful repair material. This material is based upon work supported by the US Department of Energy (DOE) National Energy Technology Laboratory (NETL) under Grant Number DE-FE0009562. This project is managed and administered by the Storage Division of the NETL and funded by DOE/NETL and cost-sharing partners. This work was funded in part by the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science

  6. Geomechanical Modeling of CO2 Injection Site to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Sobolik, S. R.; Matteo, E. N.; Dewers, T. A.; Newell, P.; Gomez, S. P.; Stormont, J.

    2014-12-01

    This paper will present the results of large-scale three-dimensional calculations simulating the hydrological-mechanical behavior of a CO2 injection reservoir and the resulting effects on wellbore casings and sealant repair materials. A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. The DOE-NETL project "Wellbore Seal Repair Using Nanocomposite Materials," is interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Two distinct computational models comprise the current modeling effort. The first is a field scale model that uses the stratigraphy, material properties, and injection history from a pilot CO2 injection operation in Cranfield, MS to develop a stress-strain history for wellbore locations from 100 to 400 meters from an injection well. The results from the field scale model are used as input to a more detailed model of a wellbore casing. The 3D wellbore model examines the impacts of various loading scenarios on a casing structure. This model has been developed in conjunction with bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. The results from these models will be used to estimate the necessary mechanical properties needed for a successful repair material. This material is based upon work supported by the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) under Grant Number DE-FE0009562. This project is managed and administered by the University of New Mexico and funded by DOE/NETL and cost-sharing partners. This work was funded in part by the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of

  7. Geomechanical Modeling of CO2 Injection Site to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Sobolik, S. R.; Gomez, S. P.; Matteo, E. N.; Stormont, J.

    2015-12-01

    This paper will present the results of large-scale three-dimensional calculations simulating the hydrological-mechanical behavior of a CO2injection reservoir and the resulting effects on wellbore casings and sealant repair materials. A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. The DOE-NETL project "Wellbore Seal Repair Using Nanocomposite Materials," is interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Two distinct computational models