[Isolation, identification and characterization of ACC deaminase-containing endophytic bacteria from halophyte Suaeda salsa].

PubMed

Teng, Songshan; Liu, Yanping; Zhao, Lei

2010-11-01

We Isolated and characterized 1-aminocyclopropane-1-carboxylate (ACC) deaminase-containing endophytic bacteria from halophyte Suaeda salsa to understand the interactions between endophytes and halophyte. ACC deaminase-containing endophytic bacteria were isolated from root, stalk and leaf of Suaeda salsa and were identified based on morphological, physiological-biochemical properties, API and 16S rRNA sequence analysis. Isolates were evaluated for their ACC deaminase, antifungal, protease activity, siderophores and phytohormones, such as indole-3-acetic acid, gibberellic acid and abscisic acid production, as well as atmospheric nitrogen fixation and phosphate solubilization. Four ACC deaminase-containing endophytic bacteria strains named as LP11, SS12, TW1 and TW2 were isolated and identified as Pseudomonas oryzihabitans, Pseudomonas sp., Pantoea agglomerans and Pseudomonas putida respectively. All the strains possessed the phosphate-solubilizing ability and could produce siderophores and phytohormones more or less. None of them could fix atmospheric nitrogen or produce protease. Only strain SS12 showed antagonism against two phytopathogenic fungi viz Fusarium oxysporum f. sp. conglutinans and F. oxysporum f. sp. cucumerinum. ACC deaminase-containing endophytic bacteria of Pseudomonas sp. and Pantoea sp. isolated from halophyte Suaeda salsa have abundant biological characteristics related to plant growth promotion, stress homeostasis regulation and biocontrol activity.

Baghdadite ceramics modulate the cross talk between human adipose stem cells and osteoblasts for bone regeneration.

PubMed

Lu, Zufu; Wang, Guocheng; Roohani-Esfahani, Iman; Dunstan, Colin R; Zreiqat, Hala

2014-03-01

Understanding interactions among the three elements (cells, scaffolds, and bioactive factors) is critical for successful tissue engineering. This study was aimed to investigate how scaffolds would affect osteogenic gene expression in human adipose tissue-derived stem cells (ASCs) or human primary osteoblasts (HOBs), and their cross talk. Either ASCs or HOBs were seeded on Baghdadite (Ca3ZrSi2O9) and hydroxyapatite/tricalcium phosphate (HA/TCP) scaffolds, and osteogenic gene expression was assessed. To further evaluate how substrate affected HOB and ASC cross talk, an indirect co-culture system with semipermeable inserts placed on the culture plate was set up to co-culture ASCs or HOBs, which were grown in monolayer or seeded on Baghdadite or HA/TCP scaffolds, and osteogenic differentiation of the cells was assessed. We found that Baghdadite scaffolds induced a significantly greater increase in RUNX2, osteopontin, bone sialoprotein, and osteocalcin gene expression in HOBs in comparison to HA/TCP scaffolds; Baghdadite scaffolds also significantly induced RUNX2 and osteopontin, but not bone sialoprotein and osteocalcin gene expression in ASCs. In the co-culture system, the HOBs on Baghdadite scaffolds more markedly promoted osteogenic gene expression in ASCs compared to HOBs in monolayer or the HOBs on HA/TCP scaffolds. In addition, the ASCs seeded on Baghdadite scaffolds more markedly promoted osteogenic gene expression in HOBs than did the ASCs on HA/TCP scaffolds. BMP-2 expression in ASCs or HOBs was increased when they were seeded on Baghdadite scaffolds, and adding Noggin into the co-culture medium largely abrogated Baghdadite scaffold-modulated ASC-HOB cross talk. In summary, Baghdadite scaffolds not only promote the osteogenic differentiation of HOBs or ASCs but also modulate the cross talk between ASCs and HOBs, in part via increasing BMP2 expression, thereby promoting their osteogenic differentiation.

Crystallization and preliminary X-ray diffraction analysis of the amidase domain of allophanate hydrolase from Pseudomonas sp. strain ADP

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

Balotra, Sahil; Newman, Janet; French, Nigel G.

2014-02-19

The amidase domain of the allophanate hydrolase AtzF from Pseudomonas sp. strain ADP has been crystallized and preliminary X-ray diffraction data have been collected. The allophanate hydrolase from Pseudomonas sp. strain ADP was expressed and purified, and a tryptic digest fragment was subsequently identified, expressed and purified. This 50 kDa construct retained amidase activity and was crystallized. The crystals diffracted to 2.5 Å resolution and adopted space group P2{sub 1}, with unit-cell parameters a = 82.4, b = 179.2, c = 112.6 Å, β = 106.6°.

Reduction of Selenite to Elemental Red Selenium by Pseudomonas sp. strain CA5

USDA-ARS?s Scientific Manuscript database

A Pseudomonas sp. that may be useful in bioremediation projects was isolated from soil. The strain is of potential value because it reduces selenite to elemental red selenium and is unusual in that it was resistant to high concentrations of both selenate and selenite. Cell of the strain removed 1....

Draft Genome Sequence of Pseudomonas sp. Strain B1, Isolated from a Contaminated Sediment

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

Pathak, Ashish; Jaswal, Rajneesh; Stothard, Paul

ABSTRACT The draft genome sequence of Pseudomonas sp. strain B1, isolated from a contaminated soil, is reported. The genome comprises 6,706,934 bases, 6,059 coding sequences, and 70 RNAs and has a G+C content of 60.3%. A suite of biodegradative genes, many located on genomic islands, were identified from strain B1, further enhancing our understanding of the versatile pseudomonads.

Draft Genome Sequence of Pseudomonas sp. Strain B1, Isolated from a Contaminated Sediment

DOE PAGES

Pathak, Ashish; Jaswal, Rajneesh; Stothard, Paul; ...

2018-06-21

ABSTRACT The draft genome sequence of Pseudomonas sp. strain B1, isolated from a contaminated soil, is reported. The genome comprises 6,706,934 bases, 6,059 coding sequences, and 70 RNAs and has a G+C content of 60.3%. A suite of biodegradative genes, many located on genomic islands, were identified from strain B1, further enhancing our understanding of the versatile pseudomonads.

Draft Genome Sequence of Pseudomonas sp. BDAL1 Reconstructed from a Bakken Shale Hydraulic Fracturing-Produced Water Storage Tank Metagenome.

PubMed

Lipus, Daniel; Ross, Daniel; Bibby, Kyle; Gulliver, Djuna

2017-03-16

We report the 5,425,832 bp draft genome of Pseudomonas sp. strain BDAL1, recovered from a Bakken shale hydraulic fracturing-produced water tank metagenome. Genome annotation revealed several key biofilm formation genes and osmotic stress response mechanisms necessary for survival in hydraulic fracturing-produced water. Copyright © 2017 Lipus et al.

Evaluation of traditional plant extracts for innate immune mechanisms and disease resistance against fish bacterial Aeromonas hydrophila and Pseudomonas sp.

NASA Astrophysics Data System (ADS)

Hardi, E. H.; Saptiani, G.; Kusuma, I. W.; Suwinarti, W.; Nugroho, R. A.

2018-03-01

The purposes of this study were to evaluate effect of ethanol herbal extracts of Boesenbergia pandurata, Solanum ferox and Zingimber zerumbet on Tilapia (Oreochromis nilaticus) innate immune mechanisms and disease resistance against Aeromonas hydrophila and Pseudomonas sp. Fish were intramuscularly injected with 0.1 mL/fish (1010 CFU mL-1) of each bacterium on the day 6th of post treatment using extract by several methods (injection, oral administration and immersion). The doses of extract were 600 ppm of B. pandurata, 900 ppm S. ferox and 200 ppm of Z. zerumbet. The percentage mortality, Relative Percent Survival (RPS) and innate immune response were assessed on weeks 1, 2, 3 and 4. All the methods were effective to enhance the immune parameters after 2 weeks application and the RPS of treatment reached more than 90 %. The results showed that the injection method of extracts was the most effective method to control A. hydrophila and Pseudomonas sp. The result indicated that all the doses of extracts could be significantly influence the immune response and protect the health status of tilapia against A. hydrophila and Pseudomonas sp. infections.

Inhibition of fish bacteria pathogen in tilapia using a concoction three of Borneo plant extracts

NASA Astrophysics Data System (ADS)

Hardi, EH; Saptiani, G.; Kusuma, IW; Suwinarti, W.; Sudaryono, A.

2018-04-01

This study was conducted to evaluate the antibacterial activity of concoction Solanum ferox, Boesenbergia pandurata and Zingimber zerumbetextract (SF, BP, and ZZ) to inhibit pathogenic bacteria in tilapia with the each concentrations 600 ppm BP, 900 ppm SF and 200 ppm ZZ. Antibacterial activity was measured by testing the concoction of three plants extract against single isolate Aeromonas hydrophila and Pseudomonas sp. and combined both bacteria (105 colony-forming units per milliliter). In this research, oxytetracycline was used as a control. Clear zone inhibition was observed at 6, 12, 18 and 24 hours after incubation at 30 °C. The results showed that the different concoction of BP: SF: ZZ have inhibitory zones against both single and joint isolate bacteria. The ratio of3:3:4 and 1:8:1 had higher antibacterial activity towards Pseudomonas sp. and 1:1:3 ratios both inhibit joint bacteria. The ZI% higher of concoction extracts against A.hydrophila is 1:1:8; 1:3:1; 3:4:3. The ZI% concoction extracts against Pseudomonas sp. ware 3:3:4 and 1:8:1 ratio. While the two bacteria combined, just 1:1:3 ratio had higher Z%. The conclusion is that a concoction of SF:BP:ZZ is effective to inhibit the growth of A.hydrophila and Pseudomonas sp., even its antibacterial ability is similar to the effectiveness of antibiotic oxytetracycline.

Geometric and computer-aided spline hob modeling

NASA Astrophysics Data System (ADS)

Brailov, I. G.; Myasoedova, T. M.; Panchuk, K. L.; Krysova, I. V.; Rogoza, YU A.

2018-03-01

The paper considers acquiring the spline hob geometric model. The objective of the research is the development of a mathematical model of spline hob for spline shaft machining. The structure of the spline hob is described taking into consideration the motion in parameters of the machine tool system of cutting edge positioning and orientation. Computer-aided study is performed with the use of CAD and on the basis of 3D modeling methods. Vector representation of cutting edge geometry is accepted as the principal method of spline hob mathematical model development. The paper defines the correlations described by parametric vector functions representing helical cutting edges designed for spline shaft machining with consideration for helical movement in two dimensions. An application for acquiring the 3D model of spline hob is developed on the basis of AutoLISP for AutoCAD environment. The application presents the opportunity for the use of the acquired model for milling process imitation. An example of evaluation, analytical representation and computer modeling of the proposed geometrical model is reviewed. In the mentioned example, a calculation of key spline hob parameters assuring the capability of hobbing a spline shaft of standard design is performed. The polygonal and solid spline hob 3D models are acquired by the use of imitational computer modeling.

Use of molecular techniques to evaluate the survival of a microorganism injected into an aquifer

USGS Publications Warehouse

Thiem, S.M.; Krumme, M.L.; Smith, R.L.; Tiedje, J.M.

1994-01-01

A PCR primer set and an internal probe that are specific for Pseudomonas sp. strain B13, a 3-chlorobenzoate-metabolizing strain, were developed. Using this primer set and probe, we were able to detect Pseudomonas sp. strain B13 DNA sequences in DNA extracted from aquifer samples 14.5 months after Pseudomonas sp. strain B13 had been injected into a sand and gravel aquifer. This primer set and probe were also used to analyze isolates from 3-chlorobenzoate enrichments of the aquifer samples by Southern blot analysis. Hybridization of Southern blots with the Pseudomonas sp. strain B13-specific probe and a catabolic probe in conjunction with restriction fragment length polymorphism (RFLP) analysis of ribosome genes was used to determine that viable Pseudomonas sp. strain B13 persisted in this environment. We isolated a new 3-chlorobenzoate-degrading strain from one of these enrichment cultures. The B13-specific probe does not hybridize to DNA from this isolate. The new strain could be the result of gene exchange between Pseudomonas sp. strain B13 and an indigenous bacterium. This speculation is based on an RFLP pattern of ribosome genes that differs from that of Pseudomonas sp. strain B13, the fact that identically sized restriction fragments hybridized to the catabolic gene probe, and the absence of any enrichable 3-chlorobenzoate-degrading strains in the aquifer prior to inoculation.

OXIDATION OF POLYCHLORINATED BIPHENYLS BY PSEUDOMONAS SP. STRAIN LB400 AND PSEUDOMONAS PSEUDOALCALIGENES KF707

EPA Science Inventory

Biphenyl-grown cells and cell extracts prepared from biphenyl-grown cells of Pseudomonas sp. strain LB400 oxidize a much wider range of chlorinated biphenyls than do analogous preparations from Pseudomonas pseudoalcaligenes KF707. These results are attributed to differences in th...

Genome Sequence of Pseudomonas sp. Strain S9, an Extracellular Arylsulfatase-Producing Bacterium Isolated from Mangrove Soil ▿

PubMed Central

Long, Mengxian; Ruan, Lingwei; Yu, Ziniu; Xu, Xun

2011-01-01

Pseudomonas sp. strain S9 was originally isolated from mangrove soil in Xiamen, China. It is an aerobic bacterium which shows extracellular arylsulfatase activity. Here, we describe the 4.8-Mb draft genome sequence of Pseudomonas sp. S9, which exhibits novel cysteine-type sulfatases. PMID:21622746

Oximidine III, a new antitumor antibiotic against transformed cells from Pseudomonas sp. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activity.

PubMed

Hayakawa, Yoichi; Tomikawa, Taijiro; Shin-ya, Kazuo; Arao, Nakako; Nagai, Koji; Suzuki, Ken-ichi

2003-11-01

Our screening for antitumor antibiotics against transformed cells resulted in the isolation of a new active metabolite, oximidine III, from Pseudomonas sp. QN05727. This substance selectively inhibited the growth of rat 3Y1 fibroblasts transformed with various oncogenes. In ras- or src-transformed cells, oximidine III arrested the cell cycle at G1 phase and increased the expression of p21WAF1.

Transformation of Dibenzo-p-Dioxin by Pseudomonas sp. Strain HH69

PubMed Central

Harms, Hauke; Wittich, Rolf-Michael; Sinnwell, Volker; Meyer, Holger; Fortnagel, Peter; Francke, Wittko

1990-01-01

Dibenzo-p-dioxin was oxidatively cleaved by the dibenzofuran-degrading bacterium Pseudomonas sp. strain HH69 to produce minor amounts of 1-hydroxydibenzo-p-dioxin and catechol, while a 2-phenoxy derivative of muconic acid was formed as the major product. Upon acidic methylation, the latter yielded the dimethylester of cis, trans-2-(2-hydroxyphenoxy)-muconic acid. PMID:16348160

Construction of the Syngonium podophyllum-Pseudomonas sp. XNN8 Symbiotic Purification System and Investigation of Its Capability of Remediating Uranium Wastewater.

PubMed

Deng, Qin-Wen; Wang, Yong-Dong; Ding, De-Xin; Hu, Nan; Sun, Jing; He, Jia-Dong; Xu, Fei

2017-02-01

The endophyte Pseudomonas sp. XNN8 was separated from Typha orientalis which can secrete indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase and siderophores and has strong resistance to uranium it was then colonized in the Syngonium podophyllum; and the S. podophyllum-Pseudomonas sp. XNN8 symbiotic purification system (SPPSPS) for uranium-containing wastewater was constructed. Afterwards, the hydroponic experiments to remove uranium from uranium-containing wastewater by the SPPSPS were conducted. After 24 days of treatment, the uranium concentrations of the wastewater samples with uranium concentrations between 0.5 and 5.0 mg/L were lowered to below 0.05 mg/L. Furthermore, the uranium in the plants was assayed using Fourier transform infrared spectroscopy (FTIR) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The Pseudomonas sp. XNN8 was found to generate substantial organic groups in the roots of the Syngonium podophyllum, which could improve the complexing capability of S. podophyllum for uranium. The uranium in the roots of S. podophyllum was found to be the uranyl phosphate (47.4 %) and uranyl acetate (52.6 %).

Stereospecific oxidation of (R)- and (S)-1-indanol by naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.

PubMed

Lee, K; Resnick, S M; Gibson, D T

1997-05-01

A recombinant Escherichia coli strain which expresses naphthalene dioxygenase (NDO) from Pseudomonas sp. strain NCIB 9816-4 oxidized (S)-1-indanol to trans-(1S,3S)-indan-1,3-diol (95.5%) and (R)-3-hydroxy-1-indanone (4.5%). The same cells oxidized (R)-1-indanol to cis-1,3-indandiol (71%), (R)-3-hydroxy-1-indanone (18.2%), and cis-1,2,3-indantriol (10.8%). Purified NDO oxidized (S)-1-indenol to both syn- and anti-2,3-dihydroxy-1-indanol.

Cometabolism of DDT analogs by a Pseudomonas sp.

PubMed Central

Francis, A J; Spanggord, R J; Ouchi, G I; Bohonos, N

1978-01-01

A Pseudomonas sp. capable of growth on several nonchlorinated and mono-p-chloro-substituted analogs of DDT as a sole carbon source degraded bis(p-chlorophenyl)methane and 1,1-bis(p-chlorophenyl)ethane only in the presence of diphenylethane. The products p-chlorophenylacetic acid and 2-(p-chlorophenyl)-propionic acid were not further metabolized by the bacterium. Other chlorinated analogs of DDT were found to be recalcitrant to cometabolic degradation with diphenylethane. PMID:637537

Draft Genome Sequence of Pseudomonas sp. Strain Ep R1 Isolated from Echinacea purpurea Roots and Effective in the Growth Inhibition of Human Opportunistic Pathogens Belonging to the Burkholderia cepacia Complex.

PubMed

Maggini, Valentina; Presta, Luana; Miceli, Elisangela; Fondi, Marco; Bosi, Emanuele; Chiellini, Carolina; Fagorzi, Camilla; Bogani, Patrizia; Di Pilato, Vincenzo; Rossolini, Gian Maria; Mengoni, Alessio; Firenzuoli, Fabio; Perrin, Elena; Fani, Renato

2017-05-18

In this announcement, we detail the draft genome sequence of the Pseudomonas sp. strain Ep R1, isolated from the roots of the medicinal plant Echinacea purpurea The elucidation of this genome sequence may allow the identification of genes associated with the production of antimicrobial compounds. Copyright © 2017 Maggini et al.

Draft Genome Sequence of Pseudomonas sp. Strain Ep R1 Isolated from Echinacea purpurea Roots and Effective in the Growth Inhibition of Human Opportunistic Pathogens Belonging to the Burkholderia cepacia Complex

PubMed Central

Maggini, Valentina; Presta, Luana; Miceli, Elisangela; Fondi, Marco; Bosi, Emanuele; Chiellini, Carolina; Fagorzi, Camilla; Bogani, Patrizia; Di Pilato, Vincenzo; Rossolini, Gian Maria; Mengoni, Alessio; Firenzuoli, Fabio; Perrin, Elena

2017-01-01

ABSTRACT In this announcement, we detail the draft genome sequence of the Pseudomonas sp. strain Ep R1, isolated from the roots of the medicinal plant Echinacea purpurea. The elucidation of this genome sequence may allow the identification of genes associated with the production of antimicrobial compounds. PMID:28522712

Biosynthesis of Polyhydroxyalkanoate from Steamed Soybean Wastewater by a Recombinant Strain of Pseudomonas sp. 61-3.

PubMed

Hokamura, Ayaka; Yunoue, Yuko; Goto, Saki; Matsusaki, Hiromi

2017-08-08

Pseudomonas sp. 61-3 accumulates a blend of poly(3-hydroxybutyrate) [P(3HB)] homopolymer and a random copolymer, poly(3-hydroxybutyrate- co -3-hydroxyalkanoate) [P(3HB- co -3HA)], consisting of 3HA units of 4-12 carbon atoms. Pseudomonas sp. 61-3 possesses two types of PHA synthases, PHB synthase (PhbC) and PHA synthases (PhaC1 and PhaC2), encoded by the phb and pha loci, respectively. The P(94 mol% 3HB- co -6 mol% 3HA) copolymer synthesized by the recombinant strain of Pseudomonas sp. 61-3 ( phbC :: tet ) harboring additional copies of phaC1 gene is known to have desirable physical properties and to be a flexible material with moderate toughness, similar to low-density polyethylene. In this study, we focused on the production of the P(3HB- co -3HA) copolymer using steamed soybean wastewater, a by-product in brewing miso , which is a traditional Japanese seasoning. The steamed soybean wastewater was spray-dried to produce a powder (SWP) and used as the sole nitrogen source for the synthesis of P(3HB- co -3HA) by the Pseudomonas sp. 61-3 recombinant strain. Hydrolyzed SWP (HSWP) was also used as a carbon and nitrogen source. P(3HB- co -3HA)s with relatively high 3HB fractions could be synthesized by a recombinant strain of Pseudomonas sp. 61-3 ( phbC :: tet ) harboring additional copies of the phaC1 gene in the presence of 2% glucose and 10-20 g/L SWP as the sole nitrogen source, producing a PHA concentration of 1.0-1.4 g/L. When HSWP was added to a nitrogen- and carbon-free medium, the recombinant strain could synthesize PHA without glucose as a carbon source. The recombinant strain accumulated 32 wt% P(3HB- co -3HA) containing 80 mol% 3HB and 20 mol% medium-chain-length 3HA with a PHA concentration of 1.0 g/L when 50 g/L of HSWP was used. The PHA production yield was estimated as 20 mg-PHA/g-HSWP, which equates to approximately 1.0 g-PHA per liter of soybean wastewater.

Biosynthesis of Polyhydroxyalkanoate from Steamed Soybean Wastewater by a Recombinant Strain of Pseudomonas sp. 61-3

PubMed Central

Hokamura, Ayaka; Yunoue, Yuko; Goto, Saki; Matsusaki, Hiromi

2017-01-01

Pseudomonas sp. 61-3 accumulates a blend of poly(3-hydroxybutyrate) [P(3HB)] homopolymer and a random copolymer, poly(3-hydroxybutyrate-co-3-hydroxyalkanoate) [P(3HB-co-3HA)], consisting of 3HA units of 4–12 carbon atoms. Pseudomonas sp. 61-3 possesses two types of PHA synthases, PHB synthase (PhbC) and PHA synthases (PhaC1 and PhaC2), encoded by the phb and pha loci, respectively. The P(94 mol% 3HB-co-6 mol% 3HA) copolymer synthesized by the recombinant strain of Pseudomonas sp. 61-3 (phbC::tet) harboring additional copies of phaC1 gene is known to have desirable physical properties and to be a flexible material with moderate toughness, similar to low-density polyethylene. In this study, we focused on the production of the P(3HB-co-3HA) copolymer using steamed soybean wastewater, a by-product in brewing miso, which is a traditional Japanese seasoning. The steamed soybean wastewater was spray-dried to produce a powder (SWP) and used as the sole nitrogen source for the synthesis of P(3HB-co-3HA) by the Pseudomonas sp. 61-3 recombinant strain. Hydrolyzed SWP (HSWP) was also used as a carbon and nitrogen source. P(3HB-co-3HA)s with relatively high 3HB fractions could be synthesized by a recombinant strain of Pseudomonas sp. 61-3 (phbC::tet) harboring additional copies of the phaC1 gene in the presence of 2% glucose and 10–20 g/L SWP as the sole nitrogen source, producing a PHA concentration of 1.0–1.4 g/L. When HSWP was added to a nitrogen- and carbon-free medium, the recombinant strain could synthesize PHA without glucose as a carbon source. The recombinant strain accumulated 32 wt% P(3HB-co-3HA) containing 80 mol% 3HB and 20 mol% medium-chain-length 3HA with a PHA concentration of 1.0 g/L when 50 g/L of HSWP was used. The PHA production yield was estimated as 20 mg-PHA/g-HSWP, which equates to approximately 1.0 g-PHA per liter of soybean wastewater. PMID:28952548

Fatty acid composition of bacteria associated with the toxic dinoflagellate Ostreopsis lenticularis and with Caribbean Palythoa species.

PubMed

Carballeira, N M; Emiliano, A; Sostre, A; Restituyo, J A; González, I M; Colón, G M; Tosteson, C G; Tosteson, T R

1998-06-01

The fatty acid composition of a Pseudomonas sp. (Alteromonas) and its host, the dinoflagellate Ostreopsis lenticularis, vectors in ciguatera fish poisoning, has been studied. The major fatty acids in O. lenticularis were 16:0, 20:5n-3, and 22:6n-3, but 18:2n-6, 18:3n-3, and 18:n-3 were also identified. In contrast to other dinoflagellates, 1 8:5n-3 was not detected in O. lenticularis. Even-chain fatty acids such as 9-16:1, 11-18:1, and 13-20:1 predominated in the Pseudomonas sp. from O. lenticularis, but 1 6-20% of (E)-11-methyl-12-octadecenoic acid was also identified. The chirality of the latter was confirmed by total synthesis (28% overall yield) starting from oxacyclotridecan-2-one. The fatty acid compositions of two other Pseudomonas species, from the palytoxin-producing zoanthids Palythoa mamillosa and P. caribdea, were also studied and were similar to that of the Pseudomonas sp. from O. lenticularis. The possibility of using some of these fatty acids as chemotaxonomic lipids in identifying marine animals that consume toxic dinoflagellates or zoanthids is discussed.

Fungal Disease Prevention in Seedlings of Rice (Oryza sativa) and Other Grasses by Growth-Promoting Seed-Associated Endophytic Bacteria from Invasive Phragmites australis

PubMed Central

Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; White, James F.

2018-01-01

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusarium blights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonas sp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested presence of genes for both compounds in the genome of SY1. HCN was detected in cultures of SY1. We conclude that microbes from non-cultivated plants may provide disease protection and promote growth of crop plants. PMID:29518024

Fungal Disease Prevention in Seedlings of Rice (Oryza sativa) and Other Grasses by Growth-Promoting Seed-Associated Endophytic Bacteria from Invasive Phragmites australis.

PubMed

Verma, Satish K; Kingsley, Kathryn L; Bergen, Marshall S; Kowalski, Kurt P; White, James F

2018-03-08

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium , Pythium and other water moulds cause seed rots during germination. Fusarium blights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass ( Cynodon dactylon ), or annual bluegrass ( Poa annua ) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum . We found that three bacteria belonging to genus Pseudomonas spp. (SLB4- P. fluorescens , SLB6- Pseudomonas sp. and SY1- Pseudomonas sp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum , 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested presence of genes for both compounds in the genome of SY1. HCN was detected in cultures of SY1. We conclude that microbes from non-cultivated plants may provide disease protection and promote growth of crop plants.

8. VIEW OF COMBINATION GEAR HOBBING MACHINE (Gould & Eberhardt, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. VIEW OF COMBINATION GEAR HOBBING MACHINE (Gould & Eberhardt, Newark, New Jersey. Patented No. 2103) AND LATHE (W.E. Shipley Machiner Co. Metal Working Machinery, Philadelphia, Pennsylvania, 1913). - Juniata Shops, Machine Shop No. 1, East of Fourth Avenue at Third Street, Altoona, Blair County, PA

Plant growth promoting rhizobacteria reduce aphid population and enhance the productivity of bread wheat.

PubMed

Naeem, Muhammad; Aslam, Zubair; Khaliq, Abdul; Ahmed, Jam Nazir; Nawaz, Ahmad; Hussain, Mubshar

2018-04-24

Plant growth promoting rhizobacteria increase plant growth and give protection against insect pests and pathogens. Due to the negative impact of chemical pesticides on environment, alternatives to these chemicals are needed. In this scenario, the biological methods of pest control offer an eco-friendly and an attractive option. In this study, the effect of two plant growth promoting rhizobacterial strains (Bacillus sp. strain 6 and Pseudomonas sp. strain 6K) on aphid population and wheat productivity was evaluated in an aphid susceptible (Pasban-90) and resistant (Inqlab-91) wheat cultivar. The seeds were inoculated with each PGPR strain, separately or the combination of both. The lowest aphid population (2.1tiller -1 ), and highest plant height (85.8cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320m -2 ), straw yield (8.6Mgha -1 ), and grain yield (4.8Mgha -1 ) were achieved when seeds were inoculated with Bacillus sp. strain 6+Pseudomonas sp. strain 6K. The grain yield of both varieties was enhanced by 35.5-38.9% with seed inoculation with both bacterial strains. Thus, the combine use of both PGPR strains viz. Bacillus sp. strain 6+Pseudomonas sp. strain 6K offers an attractive option to reduce aphid population tied with better wheat productivity. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Stereospecific oxidation of (R)- and (S)-1-indanol by naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.

PubMed Central

Lee, K; Resnick, S M; Gibson, D T

1997-01-01

A recombinant Escherichia coli strain which expresses naphthalene dioxygenase (NDO) from Pseudomonas sp. strain NCIB 9816-4 oxidized (S)-1-indanol to trans-(1S,3S)-indan-1,3-diol (95.5%) and (R)-3-hydroxy-1-indanone (4.5%). The same cells oxidized (R)-1-indanol to cis-1,3-indandiol (71%), (R)-3-hydroxy-1-indanone (18.2%), and cis-1,2,3-indantriol (10.8%). Purified NDO oxidized (S)-1-indenol to both syn- and anti-2,3-dihydroxy-1-indanol. PMID:9143136

Petroleum degradation by Pseudomonas sp. ZS1 is impeded in the presence of antagonist Alcaligenes sp. CT10.

PubMed

Liang, Jibei; Cheng, Tao; Huang, Yi; Liu, Jianhua

2018-05-28

Enhanced bioremediation is a favorable approach for petroleum pollutant cleanup, which depends on the growth of oil-eating microorganisms. In this study, we show that, by using the modified T-RFLP (mT-RFLP) methodology, one of the four major microbial populations derived from oil sludge has failed to propagate in MS medium supplemented with 2% yeast extract (YE). rDNA sequence-based analysis indicated that the four populations were Donghicola sp. CT5, Bacillus sp. CT6, Alcaligenes sp. CT10, and Pseudomonas sp. ZS1. Four purified strains grow well individually in MS medium supplemented with 2% YE, suggesting that ZS1 growth is antagonized by other strains. Co-growth analysis using mT-RFLP methodology and plate inhibitory assay indicated that ZS1 exhibited antagonistic effect against CT5 and CT6. On the other hand, co-growth analysis and plate inhibition assay showed that CT10 antagonized against ZS1. To investigate the potential compounds responsible for the antagonism, supernatant of CT10 culture was subjected to GC-MS analysis. Analysis indicated that CT10 produced a number of antimicrobial compounds including cyclodipeptide c-(L-Pro-L-Phe), which was known to inhibit the growth of Pseudomonas sp. Growth test using the purified c-(L-Pro-L-Phe) from CT10 confirmed its inhibitory activity. We further showed that, using both gravimetric and GC analysis, CT10 antagonism against the oil-eating ZS1 led to the diminishing of crude oil degradation. Together, our results indicate that bioremediation can be affected by environmental antagonists.

[Optimization of vermicomposting of organics enriched with phosphorites with participation of phosphate-mobilizing microorganisms].

PubMed

Hatsenko, M V; Volkohon, V V

2010-01-01

Active strains of microorganisms capable to mobilize phosphorus from poorly soluble compounds were isolated from the vermicompost. Representatives of Pseudomonas genus dominate in assemblages of phosphate-mobilizing humus microbiota. The strains Pseudomonas sp. 17 and Pseudomonas sp. 22, which promote liberation of the greatest quantity of water-soluble phosphorus were selected under vermicomposting of organics enriched with phosphorites with participation of active phosphate-mobilizing microorganisms. The use of compost derived with participation of Pseudomonas sp. 17 in cucumbers growth technologies makes the plants development better and raises the cultures productivity.

LONG-TERM STARVATION-INDUCTED LOSS OF ANTIBIOTIC RESISTANCE IN BACTERIA

EPA Science Inventory

Escherichia coli, Pseudomonas fluorescens, and a Pseudomonas sp. strain 133B containing the pSa plasmid were starved in well water for up to 523 days. here were two patterns of apparent antibiotic resistance loss observed. n Pseudomonas sp. strain 133B, there was no apparent loss...

Assessment of Environmental Effects of Ordnance Compounds and their Transformation Products in Coastal Ecosystems

DTIC Science & Technology

2003-12-01

common sediment bacteria Enterobacter aerogenes, Pseudomonas fluorescens, Escherichia coli, Klebsiella sp. and Aeromonas sp. before and after... Pseudomonas fluorescens, Enterobacter aerogenes, Escherichia coli, Klebsiella sp. and Aeromonas sp. are known important decomposers in sediments and...including some compounds of environmental concern such as substituted azobenzenes or phenazines (Haderlein and Schwarzenbach 1995). Aminonitrotoluenes

Effect of Pseudomonas sp. MT5 baths on Flavobacterium columnare infection of rainbow trout and on microbial diversity on fish skin and gills.

PubMed

Suomalainen, L R; Tiirola, M A; Valtonen, E T

2005-01-25

Use of Pseudomonas sp. strain MT5 to prevent and treat Flavobacterium columnare infection was studied in 2 experiments with fingerling rainbow trout Oncorhynchus mykiss. In the first experiment, length heterogeneity analysis of PCR-amplified DNA fragments (LH-PCR) was used to assess the effect of antagonistic baths on the microbial diversity of healthy and experimentally infected fish. In the 148 samples studied, no difference was found between bathed and unbathed fish, and 3 fragment lengths were detected most frequently: 500 (in 75.7% of the samples), 523 (62.2%) and 517 bp (40.5%). The species contributing to these fragment sizes were Pseudomonas sp., Rhodococcus sp. and F. columnare, respectively. A specific PCR for detection of Pseudomonas sp. MT5 was designed, but none of the tissue samples were found to be positive, most likely indicating poor adhesion of the strain during bathing. LH-PCR was found to be a more powerful tool for detecting F. columnare in fish tissue than traditional culture methods (chi2 = 3.9, df = 1, p < 0.05). Antagonistic baths had no effect on the outbreak of infection or on fish mortality. F. columnare was also detected in healthy fish prior to and after experimental infection, indicating that these fish were carriers of the disease. In the second experiment, intensive Pseudomonas sp. MT5 antagonistic baths were given daily to rainbow trout suffering from a natural columnaris infection. Again, the antagonistic bacteria had no effect on fish mortality, which reached 95 % in both control and antagonist-treated groups in 7 d.

Antimicrobial activity of α-(2-hydroxy-2-methylpropyl)-ω-(2-hydroxy-3-methylbut-2-en-1-yl) polymethylene from caesalpinia bonducella (L.) Flem

PubMed Central

Sagar, Kavitha; Vidyasagar, G. M.

2010-01-01

The compound, α-(2-hydroxy-2-methylpropyl)-ω-(2-hydroxy-3-methylbut-2-en-1-yl)polymethylene, isolated from ethyl acetate leaf extract of Caesalpinia bonducella (L.) Flem. was evaluated for antimicrobial activity against clinical isolates, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella sp., Staphylococcus citrus, Staphylococcus aureus, Escherichia coli, Candida albicans and Rhodotorula sp. using agar diffusion method. The compound exerted inhibitory zone at all concentrations and revealed the concentration-dependent activity against all tested bacterial and yeast strains comparable to standards streptomycin sulphate and gentamycin for bacteria and fluconazole and griseofulvin for Candida albicans and Rhodotorula sp. The inhibition zones were wider and clear for C. albicans and Rhodotorula sp. (IZ >20 mm) and for Pseudomonas aeruginosa, P. vulgaris and E. coli zones were greater than standards tested, whereas, zones for Klebsiella sp. and S. aureus were similar to standards. PMID:21218063

Calmodulin Regulated Spectrin Associated Protein 1 mRNA is Directly Regulated by miR-126 in Primary Human Osteoblasts.

PubMed

Strassburg, Sandra; Nabar, Nikita; Lampert, Florian; Goerke, Sebastian M; Pfeifer, Dietmar; Finkenzeller, Günter; Stark, Gerhard B; Simunovic, Filip

2017-07-01

Vascularization is essential for bone development, fracture healing, and bone tissue engineering. We have previously described that coculture of primary human osteoblasts (hOBs) and human umbilical vein endothelial cells (HUVECs) improves differentiation of both cell types. Investigating the role of microRNAs (miRNAs) in this system, we found that miR-126 is highly upregulated in hOBs following coculturing with HUVECs. In this study we performed miR-126 gain-of-function and loss-of-function experiments in hOBs followed by microarray analysis in order to identify targets of miR-126. The transcript cluster IDs were sieved by applying cut-off criteria and by selecting transcripts which were upregulated following miR-126 downregulation and vice versa. The calmodulin regulated spectrin associated protein 1 (CAMSAP1) mRNA was confirmed to be differentially regulated by miR-126. Using the luciferase reporter assay it was demonstrated that CAMSAP1 is directly targeted by miR-126. In this study, we show that miR-126 and CAMSAP1 directly interact in hOBs. This finding has potential implications for tissue engineering applications. J. Cell. Biochem. 118: 1756-1763, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

In vitro antimicrobial activity of extracts and isolated compound from Dalbergia stipulacea Roxb. leaves

NASA Astrophysics Data System (ADS)

Kumar, Arvind; Bhat, Tahir Ahmad; Singh, Rattan Deep

2017-07-01

The study was designed to examine the in vitro antimicrobial efficacy of extracts and isolated compound of Dalbergia stipulacea. Combined extracts (chloroform and methanol) of plant leaves fractionated with n-butanol loaded with column afforded a flavonoid glycoside compound identified as luteolin 4'-rutinoside. Different extracts and isolated compound exhibited pronounced antibacterial and antifungal varied activities against four bacteria (Clostridium acetobutylinium, Bacillus subtilis, Streptococcus mutans, and Pseudomonas sp.) and one fungus (Candida albicans) susceptibility were determined using disc diffusion method. The minimum inhibitory concentration (MIC) of extracts and isolated compounds was determined by broth dilution method. The maximum activity was shown by chloroform extract against C. albicans with a zone of inhibition of 17 mm and minimum activity was displayed by methanolic extract against Pseudomonas sp. with 5 mm. However, isolated compound has shown maximum activity against Pseudomonas sp. with 15 mm. The MIC values higher in methanol extract against Pseudomonas sp. and isolated compound shows good against Pseudomonas sp. and B. subtilis. Our findings indicate that plant could be used as a good antimicrobial agent in food, pharmaceutical and bio-pesticide industries.

LONG-TERM STARVATION-INDUCED LOSS OF APPARENT ANTIBIOTIC RESISTANCE IN CELLS CONTAINING THE PLASMID PSA

EPA Science Inventory

Escherichia coli, Pseudomonas fluorescens, and a Pseudomonas sp. strain 133B containing the pSa plasmid were starved in well water for up to 523 days. There were two patterns of apparent antibiotic resistance loss observed. In Pseudomonas sp. strain 133B, there was no apparent lo...

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

PubMed

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

2014-04-01

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

High-density polyethylene (HDPE)-degrading potential bacteria from marine ecosystem of Gulf of Mannar, India.

PubMed

Balasubramanian, V; Natarajan, K; Hemambika, B; Ramesh, N; Sumathi, C S; Kottaimuthu, R; Rajesh Kannan, V

2010-08-01

Assessment of high-density polyethylene (HDPE)-degrading bacteria isolated from plastic waste dumpsites of Gulf of Mannar. Rationally, 15 bacteria (GMB1-GMB15) were isolated by enrichment technique. GMB5 and GMB7 were selected for further studies based on their efficiency to degrade the HDPE and identified as Arthrobacter sp. and Pseudomonas sp., respectively. Assessed weight loss of HDPE after 30 days of incubation was nearly 12% for Arthrobacter sp. and 15% for Pseudomonas sp. The bacterial adhesion to hydrocarbon (BATH) assay showed that the cell surface hydrophobicity of Pseudomonas sp. was higher than Arthrobacter sp. Both fluorescein diacetate hydrolysis and protein content of the biofilm were used to test the viability and protein density of the biomass. Acute peak elevation was observed between 2 and 5 days of inoculation for both bacteria. Fourier transform infrared (FT-IR) spectrum showed that keto carbonyl bond index (KCBI), Ester carbonyl bond index (ECBI) and Vinyl bond index (VBI) were increased indicating changes in functional group(s) and/or side chain modification confirming the biodegradation. The results pose us to suggest that both Pseudomonas sp. and Arthrobacter sp. were proven efficient to degrade HDPE, albeit the former was more efficacious, yet the ability of latter cannot be neglected. Recent alarm on ecological threats to marine system is dumping plastic waste in the marine ecosystem and coastal arena by anthropogenic activity. In maintenance phase of the plastic-derived polyethylene waste, the microbial degradation plays a major role; the information accomplished in this work will be the initiating point for the degradation of polyethylene by indigenous bacterial population in the marine ecosystem and provides a novel eco-friendly solution in eco-management.

Isolation and characterization of a novel simazine-degrading bacterium from agricultural soil of central Chile, Pseudomonas sp. MHP41.

PubMed

Hernández, Marcela; Villalobos, Patricio; Morgante, Verónica; González, Myriam; Reiff, Caroline; Moore, Edward; Seeger, Michael

2008-09-01

s-Triazine herbicides are used extensively in South America in agriculture and forestry. In this study, a bacterium designated as strain MHP41, capable of degrading simazine and atrazine, was isolated from agricultural soil in the Quillota valley, central Chile. Strain MHP41 is able to grow in minimal medium, using simazine as the sole nitrogen source. In this medium, the bacterium exhibited a growth rate of mu=0.10 h(-1), yielding a high biomass of 4.2 x 10(8) CFU mL(-1). Resting cells of strain MHP41 degrade more than 80% of simazine within 60 min. The atzA, atzB, atzC, atzD, atzE and atzF genes encoding the enzymes of the simazine upper and lower pathways were detected in strain MHP41. The motile Gram-negative bacterium was identified as a Pseudomonas sp., based on the Biolog microplate system and comparative sequence analyses of the 16S rRNA gene. Amplified ribosomal DNA restriction analysis allowed the differentiation of strain MHP41 from Pseudomonas sp. ADP. The comparative 16S rRNA gene sequence analyses suggested that strain MHP41 is closely related to Pseudomonas nitroreducens and Pseudomonas multiresinovorans. This is the first s-triazine-degrading bacterium isolated in South America. Strain MHP41 is a potential biocatalyst for the remediation of s-triazine-contaminated environments.

In Vitro Antimicrobial Potential of the Lichen Parmotrema sp. Extracts against Various Pathogens.

PubMed

Chauhan, Ritika; Abraham, Jayanthi

2013-07-01

The ongoing increasing antibiotic resistance is one of the biggest challenges faced by global public health. The perennial need for new antimicrobials against a background of increasing antibiotic resistance in pathogenic and opportunistic microorganisms obliges the scientific community to constantly develop new drugs and antimicrobial agents. Lichens are known prolific sources of natural antimicrobial drugs and biologically active natural products. This study was aimed to explore in vitro antimicrobial activity of lichen Parmotrema sp. The methanol and aqueous extracts of lichen Parmotrema sp. was extracted using Soxhlet extractor. Antibiotic assessment of methanol and aqueous extracts was done against eight bacterial (Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Salmonella sp., Shigella sp., Enterococci faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae,) clinical pathogens and five plant pathogenic fungal strains (Aspergillus terreus strain JAS1, Scedosporium sp. JAS1, Ganoderma sp. JAS4, Candida tropicalis and Fusarium sp.) by Kirby-Bauer method. The methanol lichen Parmotrema sp. extract inhibited all the test organisms. The highest antibacterial activity was found against Pseudomonas aeruginosa and Staphylococcus aureus. The weakest activity was manifested in Salmonella sp. and Scedosporium sp. JAS1. Strong antifungal effect was found against Ganoderma sp. JAS4 and Fusarium sp. The aqueous lichen Parmotrema sp. extract revealed neither antibacterial nor antifungal activity. The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens.

Respiration of 2,4,6-Trinitrotoluene by Pseudomonas sp. Strain JLR11

PubMed Central

Esteve-Nuñez, Abraham; Lucchesi, Gloria; Philipp, Bodo; Schink, Bernhard; Ramos, Juan L.

2000-01-01

Under anoxic conditions Pseudomonas sp. strain JLR11 can use 2,4,6-trinitrotoluene (TNT) as the sole N source, releasing nitrite from the aromatic ring and subsequently reducing it to ammonium and incorporating it into C skeletons. This study shows that TNT can also be used as a terminal electron acceptor in respiratory chains under anoxic conditions by Pseudomonas sp. strain JLR11. TNT-dependent proton translocation coupled to the reduction of TNT to aminonitrotoluenes has been observed in TNT-grown cells. This extrusion did not occur in nitrate-grown cells or in anaerobic TNT-grown cells treated with cyanide, a respiratory chain inhibitor. We have shown that in a membrane fraction prepared from Pseudomonas sp. strain JLR11 grown on TNT under anaerobic conditions, the synthesis of ATP was coupled to the oxidation of molecular hydrogen and to the reduction of TNT. This phosphorylation was uncoupled by gramicidin. Respiration by Pseudomonas sp. strain JLR11 is potentially useful for the biotreatment of TNT in polluted waters and soils, particularly in phytorhizoremediation, in which bacterial cells are transported to the deepest root zones, which are poor in oxygen. PMID:10671458

Isolation and amino acid sequence of a dehydratase acting on d-erythro-3-hydroxyaspartate from Pseudomonas sp. N99, and its application in the production of optically active 3-hydroxyaspartate.

PubMed

Nagano, Hiroyuki; Shibano, Kana; Matsumoto, Yu; Yokota, Atsushi; Wada, Masaru

2017-06-01

An enzyme catalyzing the ammonia-lyase reaction for the conversion of d-erythro-3-hydroxyaspartate to oxaloacetate was purified from the cell-free extract of a soil-isolated bacterium Pseudomonas sp. N99. The enzyme exhibited ammonia-lyase activity toward l-threo-3-hydroxyaspartate and d-erythro-3-hydroxyaspartate, but not toward other 3-hydroxyaspartate isomers. The deduced amino acid sequence of the enzyme, which belongs to the serine/threonine dehydratase family, shows similarity to the sequence of l-threo-3-hydroxyaspartate ammonia-lyase (EC 4.3.1.16) from Pseudomonas sp. T62 (74%) and Saccharomyces cerevisiae (64%) and serine racemase from Schizosaccharomyces pombe (65%). These results suggest that the enzyme is similar to l-threo-3-hydroxyaspartate ammonia-lyase from Pseudomonas sp. T62, which does not act on d-erythro-3-hydroxyaspartate. We also then used the recombinant enzyme expressed in Escherichia coli to produce optically pure l-erythro-3-hydroxyaspartate and d-threo-3-hydroxyaspartate from the corresponding dl-racemic mixtures. The enzymatic resolution reported here is one of the simplest and the first enzymatic method that can be used for obtaining optically pure l-erythro-3-hydroxyaspartate.

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

PubMed

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

2011-01-01

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

Lipase and its modulator from Pseudomonas sp. strain KFCC 10818: proline-to-glutamine substitution at position 112 induces formation of enzymatically active lipase in the absence of the modulator.

PubMed

Kim, E K; Jang, W H; Ko, J H; Kang, J S; Noh, M J; Yoo, O J

2001-10-01

A lipase gene, lipK, and a lipase modulator gene, limK, of Pseudomonas sp. strain KFCC 10818 have been cloned, sequenced, and expressed in Escherichia coli. The limK gene is located immediately downstream of the lipK gene. Enzymatically active lipase was produced only in the presence of the limK gene. The effect of the lipase modulator LimK on the expression of active lipase was similar to those of the Pseudomonas subfamily I.1 and I.2 lipase-specific foldases (Lifs). The deduced amino acid sequence of LimK shares low homology (17 to 19%) with the known Pseudomonas Lifs, suggesting that Pseudomonas sp. strain KFCC 10818 is only distantly related to the subfamily I.1 and I.2 Pseudomonas species. Surprisingly, a lipase variant that does not require LimK for its correct folding was isolated in the study to investigate the functional interaction between LipK and LimK. When expressed in the absence of LimK, the P112Q variant of LipK formed an active enzyme and displayed 63% of the activity of wild-type LipK expressed in the presence of LimK. These results suggest that the Pro(112) residue of LipK is involved in a key step of lipase folding. We expect that the novel finding of this study may contribute to future research on efficient expression or refolding of industrially important lipases and on the mechanism of lipase folding.

Lipase and Its Modulator from Pseudomonas sp. Strain KFCC 10818: Proline-to-Glutamine Substitution at Position 112 Induces Formation of Enzymatically Active Lipase in the Absence of the Modulator

PubMed Central

Kim, Eun Kyung; Jang, Won Hee; Ko, Jung Ho; Kang, Jong Seok; Noh, Moon Jong; Yoo, Ook Joon

2001-01-01

A lipase gene, lipK, and a lipase modulator gene, limK, of Pseudomonas sp. strain KFCC 10818 have been cloned, sequenced, and expressed in Escherichia coli. The limK gene is located immediately downstream of the lipK gene. Enzymatically active lipase was produced only in the presence of the limK gene. The effect of the lipase modulator LimK on the expression of active lipase was similar to those of the Pseudomonas subfamily I.1 and I.2 lipase-specific foldases (Lifs). The deduced amino acid sequence of LimK shares low homology (17 to 19%) with the known Pseudomonas Lifs, suggesting that Pseudomonas sp. strain KFCC 10818 is only distantly related to the subfamily I.1 and I.2 Pseudomonas species. Surprisingly, a lipase variant that does not require LimK for its correct folding was isolated in the study to investigate the functional interaction between LipK and LimK. When expressed in the absence of LimK, the P112Q variant of LipK formed an active enzyme and displayed 63% of the activity of wild-type LipK expressed in the presence of LimK. These results suggest that the Pro112 residue of LipK is involved in a key step of lipase folding. We expect that the novel finding of this study may contribute to future research on efficient expression or refolding of industrially important lipases and on the mechanism of lipase folding. PMID:11566993

The glycerophospholipid inventory of Pseudomonas putida is conserved between strains and enables growth condition‐related alterations

PubMed Central

Rühl, Jana; Hein, Eva‐Maria; Hayen, Heiko; Schmid, Andreas; Blank, Lars M.

2012-01-01

Summary Microorganisms, such as Pseudomonas putida, utilize specific physical properties of cellular membrane constituents, mainly glycerophospholipids, to (re‐)adjust the membrane barrier to environmental stresses. Building a basis for membrane composition/function studies, we inventoried the glycerophospholipids of different Pseudomonas and challenged membranes of growing cells with n‐butanol. Using a new high‐resolution liquid chromatography/mass spectrometry (LC/MS) method, 127 glycerophospholipid species [e.g. phosphatidylethanolamine PE(32:1)] with up to five fatty acid combinations were detected. The glycerophospholipid inventory consists of 305 distinct glycerophospholipids [e.g. PE(16:0/16:1)], thereof 14 lyso‐glycerophospholipids, revealing conserved compositions within the four investigated pseudomonads P. putida KT2440, DOT‐T1E, S12 and Pseudomonas sp. strain VLB120. Furthermore, we addressed the influence of environmental conditions on the glycerophospholipid composition of Pseudomonas via long‐time exposure to the sublethal n‐butanol concentration of 1% (v/v), focusing on: (i) relative amounts of glycerophospholipid species, (ii) glycerophospholipid head group composition, (iii) fatty acid chain length, (iv) degree of saturation and (v) cis/trans isomerization of unsaturated fatty acids. Observed alterations consist of changing head group compositions and for the solvent‐sensitive strain KT2440 diminished fatty acid saturation degrees. Minor changes in the glycerophospholipid composition of the solvent‐tolerant strains P. putida S12 and Pseudomonas sp. VLB120 suggest different strategies of the investigated Pseudomonas to maintain the barrier function of cellular membranes. PMID:21895997

Biodegradation of phenol and benzene by endophytic bacterial strains isolated from refinery wastewater-fed Cannabis sativa.

PubMed

Iqbal, Aneela; Arshad, Muhammad; Hashmi, Imran; Karthikeyan, Raghupathy; Gentry, Terry J; Schwab, Arthur Paul

2017-06-13

The presence of benzene and phenol in the environment can lead to serious health effects in humans and warrant development of efficient cleanup strategies. The aim of the present work was to assess the potential of indigenous endophytic bacterial strains to degrade benzene and phenol. Seven strains were successfully isolated from Cannabis sativa plants irrigated with oil refinery wastewater. Molecular characterization was performed by 16S rRNA gene sequencing. Phenol was biodegraded almost completely with Achromobacter sp. (AIEB-7), Pseudomonas sp. (AIEB-4), and Alcaligenes sp. (AIEB-6) at 250, 500, and 750 mg L -1 ; however, the degradation was only 81%, 72%, and 69%, respectively, when exposed to 1000 mg L -1 . Bacillus sp. (AIEB-1), Enterobacter sp. (AIEB-3), and Acinetobacter sp. (AIEB-2) degraded benzene significantly at 250, 500, and 750 mg L -1 . However, these strains showed 80%, 72%, and 68% benzene removal at 1000 mg L -1 exposure, respectively. Rates of degradation could be modeled with first-order kinetics with rate constant values of 1.86 × 10 -2 for Pseudomonas sp. (AIEB-4) and 1.80 × 10 -2  h -1 for Bacillus sp. (AIEB-1) and half-lives of 1.5 and 1.6 days, respectively. These results establish a foundation for further testing of the phytoremediation of hydrocarbon-contaminated soils in the presence of these endophytic bacteria.

Desaturation, dioxygenation, and monooxygenation reactions catalyzed by naphthalene dioxygenase from Pseudomonas sp. strain 9816-4.

PubMed

Gibson, D T; Resnick, S M; Lee, K; Brand, J M; Torok, D S; Wackett, L P; Schocken, M J; Haigler, B E

1995-05-01

The stereospecific oxidation of indan and indene was examined with mutant and recombinant strains expressing naphthalene dioxygenase of Pseudomonas sp. strain 9816-4. Pseudomonas sp. strain 9816/11 and Escherichia coli JM109(DE3)[pDTG141] oxidized indan to (+)-(1S)-indanol, (+)-cis-(1R,2S)-indandiol, (+)-(1S)-indenol, and 1-indanone. The same strains oxidized indene to (+)-cis-(1R,2S)-indandiol and (+)-(1S)-indenol. Purified naphthalene dioxygenase oxidized indan to the same four products formed by strains 9816/11 and JM109(DE3)[pDTG141]. In addition, indene was identified as an intermediate in indan oxidation. The major products formed from indene by purified naphthalene dioxygenase were (+)-(1S)-indenol and (+)-(1R,2S)-indandiol. The results show that naphthalene dioxygenase catalyzes the enantiospecific monooxygenation of indan to (+)-(1S)-indanol and the desaturation of indan to indene, which then serves as a substrate for the formation of (+)-(1R,2S)-indandiol and (+)-(1S)-indenol. The relationship of the desaturase, monooxygenase, and dioxygenase activities of naphthalene dioxygenase is discussed with reference to reactions catalyzed by toluene dioxygenase, plant desaturases, cytochrome P-450, methane monooxygenase, and other bacterial monooxygenases.

Desaturation, dioxygenation, and monooxygenation reactions catalyzed by naphthalene dioxygenase from Pseudomonas sp. strain 9816-4.

PubMed Central

Gibson, D T; Resnick, S M; Lee, K; Brand, J M; Torok, D S; Wackett, L P; Schocken, M J; Haigler, B E

1995-01-01

The stereospecific oxidation of indan and indene was examined with mutant and recombinant strains expressing naphthalene dioxygenase of Pseudomonas sp. strain 9816-4. Pseudomonas sp. strain 9816/11 and Escherichia coli JM109(DE3)[pDTG141] oxidized indan to (+)-(1S)-indanol, (+)-cis-(1R,2S)-indandiol, (+)-(1S)-indenol, and 1-indanone. The same strains oxidized indene to (+)-cis-(1R,2S)-indandiol and (+)-(1S)-indenol. Purified naphthalene dioxygenase oxidized indan to the same four products formed by strains 9816/11 and JM109(DE3)[pDTG141]. In addition, indene was identified as an intermediate in indan oxidation. The major products formed from indene by purified naphthalene dioxygenase were (+)-(1S)-indenol and (+)-(1R,2S)-indandiol. The results show that naphthalene dioxygenase catalyzes the enantiospecific monooxygenation of indan to (+)-(1S)-indanol and the desaturation of indan to indene, which then serves as a substrate for the formation of (+)-(1R,2S)-indandiol and (+)-(1S)-indenol. The relationship of the desaturase, monooxygenase, and dioxygenase activities of naphthalene dioxygenase is discussed with reference to reactions catalyzed by toluene dioxygenase, plant desaturases, cytochrome P-450, methane monooxygenase, and other bacterial monooxygenases. PMID:7751268

Arsenic redox transformation by Pseudomonas sp. HN-2 isolated from arsenic-contaminated soil in Hunan, China.

PubMed

Zhang, Zhennan; Yin, Naiyi; Cai, Xiaolin; Wang, Zhenzhou; Cui, Yanshan

2016-09-01

A mesophilic, Gram-negative, arsenite[As(III)]-oxidizing and arsenate[As(V)]-reducing bacterial strain, Pseudomonas sp. HN-2, was isolated from an As-contaminated soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri. Under aerobic conditions, this strain oxidized 92.0% (61.4μmol/L) of arsenite to arsenate within 3hr of incubation. Reduction of As(V) to As(III) occurred in anoxic conditions. Pseudomonas sp. HN-2 is among the first soil bacteria shown to be capable of both aerobic As(III) oxidation and anoxic As(V) reduction. The strain, as an efficient As(III) oxidizer and As(V) reducer in Pseudomonas, has the potential to impact arsenic mobility in both anoxic and aerobic environments, and has potential application in As remediation processes. Copyright © 2016. Published by Elsevier B.V.

Improving corn silage quality in the top layer of farm bunker silos through the use of a next-generation barrier film with high impermeability to oxygen.

PubMed

Borreani, G; Tabacco, E

2014-01-01

This study examined the effect on the fermentation, chemical, and microbiological quality of corn silage covered with a new-generation high oxygen barrier film (HOB) made with a special grade of ethylene-vinyl alcohol (EVOH) compared with a standard polyethylene film (PE). Two bunkers (farms 1 and 2) were divided into 2 parts lengthwise so that half of the silo would be covered with PE film and the other with HOB film. Plastic net bags with fresh chopped corn were buried in the upper layer (close to and far from the wall) and in the central part of the bunkers. During spring-summer consumption, the bags were unloaded, weighed, and subsampled to analyze the dry matter (DM) content, neutral detergent fiber and starch contents, pH, lactic and monocarboxylic acids, yeast and mold counts, aerobic and anaerobic spore-former counts, and aerobic stability. We also determined the economic benefit of applying the novel covering. The top layer of silage conserved under the HOB film had a higher lactic acid content and lower pH; lower counts of yeasts, molds, and aerobic and anaerobic spore-formers; higher aerobic stability; and lower DM losses than the silage conserved under the PE film. The use of the HOB film prevented almost all of the silage in the upper layer from spoiling; only 2 out of 32 samples had a mold count >6log10 cfu/g. This led to a net economic gain when the HOB film was used on both farms due to the increased DM recovery and reduced labor time required to clean the upper layer, even though the HOB film cost about 2.3 times more than the PE film. Furthermore, use of the HOB film, which ensures a longer shelf life of silage during consumption, reduced the detrimental effect of yeasts, molds, and aerobic and anaerobic spore-formers on the nutritional and microbiological quality of the unloaded silage. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The Tale of a Neglected Energy Source: Elevated Hydrogen Exposure Affects both Microbial Diversity and Function in Soil.

PubMed

Khdhiri, Mondher; Piché-Choquette, Sarah; Tremblay, Julien; Tringe, Susannah G; Constant, Philippe

2017-06-01

The enrichment of H 2 -oxidizing bacteria (HOB) by H 2 generated by nitrogen-fixing nodules has been shown to have a fertilization effect on several different crops. The benefit of HOB is attributed to their production of plant growth-promoting factors, yet their interactions with other members of soil microbial communities have received little attention. Here we report that the energy potential of H 2 , when supplied to soil, alters ecological niche partitioning of bacteria and fungi, with multifaceted consequences for both generalist and specialist microbial functions. We used dynamic microcosms to expose soil to the typical atmospheric H 2 mixing ratio (0.5 ppmv) permeating soils, as well as mixing ratios comparable to those found at the soil-nodule interface (10,000 ppmv). Elevated H 2 exposure exerted direct effects on two HOB subpopulations distinguished by their affinity for H 2 while enhancing community level carbon substrate utilization potential and lowering CH 4 uptake activity in soil. We found that H 2 triggered changes in the abundance of microorganisms that were reproducible yet inconsistent across soils at the taxonomic level and even among HOB. Overall, H 2 exposure altered microbial process rates at an intensity that depends upon soil abiotic and biotic features. We argue that further examination of direct and indirect effects of H 2 on soil microbial communities will lead to a better understanding of the H 2 fertilization effect and soil biogeochemical processes. IMPORTANCE An innovative dynamic microcosm chamber system was used to demonstrate that H 2 diffusing in soil triggers changes in the distribution of HOB and non-HOB. Although the response was uneven at the taxonomic level, an unexpected coordinated response of microbial functions was observed, including abatement of CH 4 oxidation activity and stimulation of carbon turnover. Our work suggests that elevated H 2 rewires soil biogeochemical structure through a combination of direct effects on the growth and persistence of HOB and indirect effects on a variety of microbial processes involving HOB and non-HOB. Copyright © 2017 American Society for Microbiology.

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

PubMed

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

2003-09-01

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

A Synthetic Alternative to Canonical One-Carbon Metabolism.

PubMed

Bouzon, Madeleine; Perret, Alain; Loreau, Olivier; Delmas, Valérie; Perchat, Nadia; Weissenbach, Jean; Taran, Frédéric; Marlière, Philippe

2017-08-18

One-carbon metabolism is an ubiquitous metabolic pathway that encompasses the reactions transferring formyl-, hydroxymethyl- and methyl-groups bound to tetrahydrofolate for the synthesis of purine nucleotides, thymidylate, methionine and dehydropantoate, the precursor of coenzyme A. An alternative cyclic pathway was designed that substitutes 4-hydroxy-2-oxobutanoic acid (HOB), a compound absent from known metabolism, for the amino acids serine and glycine as one-carbon donors. It involves two novel reactions, the transamination of l-homoserine and the transfer of a one-carbon unit from HOB to tetrahydrofolate releasing pyruvate as coproduct. Since canonical reactions regenerate l-homoserine from pyruvate by carboxylation and subsequent reduction, every one-carbon moiety made available for anabolic reactions originates from CO 2 . The HOB-dependent pathway was established in an Escherichia coli auxotroph selected for prototrophy using long-term cultivation protocols. Genetic, metabolic and biochemical evidence support the emergence of a functional HOB-dependent one-carbon pathway achieved with the recruitment of the two enzymes l-homoserine transaminase and HOB-hydroxymethyltransferase and of HOB as an essential metabolic intermediate. Escherichia coli biochemical reprogramming was achieved by minimally altering canonical metabolism and leveraging on natural selection mechanisms, thereby launching the resulting strain on an evolutionary trajectory diverging from all known extant species.

Therapeutic touch affects DNA synthesis and mineralization of human osteoblasts in culture.

PubMed

Jhaveri, Ankur; Walsh, Stephen J; Wang, Yatzen; McCarthy, MaryBeth; Gronowicz, Gloria

2008-11-01

Complementary and alternative medicine (CAM) techniques are commonly used in hospitals and private medical facilities; however, the effectiveness of many of these practices has not been thoroughly studied in a scientific manner. Developed by Dr. Dolores Krieger and Dora Kunz, Therapeutic Touch is one of these CAM practices and is a highly disciplined five-step process by which a practitioner can generate energy through their hands to promote healing. There are numerous clinical studies on the effects of TT but few in vitro studies. Our purpose was to determine if Therapeutic Touch had any effect on osteoblast proliferation, differentiation, and mineralization in vitro. TT was performed twice a week for 10 min each on human osteoblasts (HOBs) and on an osteosarcoma-derived cell line, SaOs-2. No significant differences were found in DNA synthesis, assayed by [(3)H]-thymidine incorporation at 1 or 2 weeks for SaOs-2 or 1 week for HOBs. However, after four TT treatments in 2 weeks, TT significantly (p = 0.03) increased HOB DNA synthesis compared to controls. Immunocytochemistry for Proliferating Cell Nuclear Antigen (PCNA) confirmed these data. At 2 weeks in differentiation medium, TT significantly increased mineralization in HOBs (p = 0.016) and decreased mineralization in SaOs-2 (p = 0.0007), compared to controls. Additionally, Northern blot analysis indicated a TT-induced increase in mRNA expression for Type I collagen, bone sialoprotein, and alkaline phosphatase in HOBs and a decrease of these bone markers in SaOs-2 cells. In conclusion, Therapeutic Touch appears to increase human osteoblast DNA synthesis, differentiation and mineralization, and decrease differentiation and mineralization in a human osteosarcoma-derived cell line. (c) 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

The effect of patient migration in bed on torso elevation.

PubMed

Wiggermann, Neal; Kotowski, Susan; Davis, Kermit; VanGilder, Catherine

2015-01-01

Elevating the hospital head of bed (HOB) to at least 30° is recommended practice to reduce the risk of ventilator-associated pneumonia (VAP) in mechanically ventilated patients. However, this common practice prescribes the position of the bed and not of the patient, which could be significantly different. The aim of this research was to determine the relationship between patient migration in bed and anatomic torso angle. Ten healthy participants were positioned in a hospital bed that was raised from flat to 30° and 45° HOB elevations. Prior to bed movement, participants were aligned to different locations along the length of the bed to represent different amounts of migration. A motion capture system was used to measure torso angle and migration toward the foot of the bed. The relationship between torso angle and migration was estimated by linear regression. Patient migration resulted in lower torso angles for both 30° and 45° HOB articulations. A migration of 10 cm resulted in a loss of 9.1° and 13.0° of torso angle for HOB articulations of 30° and 45°, respectively (for 30° articulations: (Equation is included in full-text article.)= -0.91, R = .96; for 45° articulations: (Equation is included in full-text article.)= -1.30, R = .98). Migration toward the foot of the bed flattens the torso. To maintain a torso angle that is likely to protect against VAP, healthcare providers need to manage both HOB angle and migration. Protocols and equipment that minimize patient migration will help support effective clinical practice. Future research on patient migration, as it relates to VAP or other outcomes, should measure patient torso angle to allow accurate translation of the results to care practice.

Synthetic extreme environments: overlooked sources of potential biotechnologically relevant microorganisms.

PubMed

Sibanda, Timothy; Selvarajan, Ramganesh; Tekere, Memory

2017-05-01

Synthetic extreme environments like carwash effluent tanks and drains are potential sources of biotechnologically important microorganisms and molecules which have, however, remained unexplored. Using culture- and molecular-based methods, a total of 17 bacterial isolates belonging to the genera Shewanella, Proteus, Paenibacillus, Enterobacter and Citrobacter, Aeromonas, Pseudomonas and Pantoea were identified. Hydrocarbon utilization and enzyme production screening assays showed that Aeromonas sp. CAC11, Paenibacillus sp. CAC12 and Paenibacillus sp. CAC13 and Citrobacter sp. PCW7 were able to degrade benzanthracene, naphthalene and diesel oil, Paenibacillus sp. CAC12 and Paenibacillus sp. CAC13 could produce cellulase enzyme, while Proteus sp. BPS2, Pseudomonas sp. SAS8 and Proteus sp. CAL3 could produce lipase. GC-MS analysis of bacterial secondary metabolites resulted in identification of 107 different compounds produced by Proteus sp. BPS2, Paenibacillus sp. CAC12, Pseudomonas sp. SAS8, Proteus sp. CAL3 and Paenibacillus sp. CAC13. Most of the compounds identified by both GC-MS and LC-MS have previously been determined to have antibacterial, antifungal and/or anticancer properties. Further, microbial metabolites which have previously been known to be produced only by plants or microorganisms found in natural extreme environments were also identified in this study. This research has revealed the immense bioresource potential of microorganisms inhabiting synthetic extreme environments. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Comparative studies on crosslinked and uncrosslinked natural rubber biodegradation by Pseudomonas sp.

PubMed

Roy, Ram Vinod; Das, Mithu; Banerjee, Rintu; Bhowmick, Anil K

2006-12-01

A comparative study on biodegradation of di-cumyl peroxide (DCP) crosslinked and uncrosslinked natural rubber by Pseudomonas sp. was carried out. Decrease in organic carbon content along with the changes in tensile strength of the treated rubber, both DCP crosslinked and uncrosslinked natural rubber, indicated rubber hydrocarbon utilization by the Pseudomonas sp. A decrease in 60.88% MPa and 41.66% MPa was observed after five month's old treated uncrosslinked natural rubber and DCP crosslinked rubber, respectively. Biodegradation was more pronounced in natural uncrosslinked rubber, which was further confirmed by the formation of aldehydic compounds with decrease in CH2 stretching frequencies.

In Vitro Studies of Semisynthetic α- (Substituted-Ureido) Penicillins

PubMed Central

Bodey, Gerald P.; Stewart, Dorothy

1971-01-01

The activity of three α-(substituted-ureido) penicillins was evaluated in vitro against 599 clinical isolates of gram-negative bacilli, by use of the broth-dilution technique. At a concentration of 12.5 μg or less/ml, BL-P1597 inhibited 90% of isolates of Pseudomonas sp., 56% of Enterobacter sp., 67% of indole-positive Proteus spp., 72% of Escherichia coli, and 85% of Proteus mirabilis. BL-P1654 had similar activity, whereas BL-P1532 was much less active. At a concentration of 25 μg or less/ml, BL-P1597 also inhibited nearly 60% of isolates of Klebsiella sp. and nearly 40% of Serratia sp. BL-P1597 and BL-P1654 were as active as ampicillin and carbenicillin against E. coli and P. mirabilis. They were less active than carbenicillin against indole-positive Proteus spp. Both drugs were substantially more active than carbenicillin against Pseudomonas sp. A strain of Pseudomonas sp. which developed resistance to carbenicillin also developed resistance to the α-(substituted-ureido) penicillins simultaneously. PMID:4930281

Fungal disease prevention in seedlings of rice (Oryza sativa) and other grasses by growth-promoting seed-associated endophytic bacteria from invasive Phragmites australis

USGS Publications Warehouse

Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; Kowalski, Kurt P.; White, James F.

2018-01-01

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusariumblights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonassp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested presence of genes for both compounds in the genome of SY1. HCN was detected in cultures of SY1. We conclude that microbes from non-cultivated plants may provide disease protection and promote growth of crop plants.

Role of beta 1-4 linked polymers in the biofilm structure of marine Pseudomonas sp. CE-2 on 304 stainless steel coupons.

PubMed

Jain, Anand; Bhosle, Narayan B

2008-01-01

Pseudomonas sp CE-2 cells attach and form biofilms on 304-stainless steel (SS) coupons. A series of experiments were carried out in order to understand the role of exopolysaccharides (EPS) in the formation and maintenance of CE-2 biofilms on SS coupons. The biofilm density and EPS concentration increased over the period of incubation and the highest values for both were recorded after 72 h. Calcofluor and the lectin concanavalin A (Con A) showed a positive interaction with 72-h old biofilms, indicating the presence of beta 1-4 linked polymers, and alpha-d-glucose and alpha-d-mannose in the biofilm matrix of CE-2. When the CE-2 cells were grown in the presence of calcofluor (200 microg ml(-1)), biofilm formation was significantly reduced (approximately 85%). Conversely, the lectins Con A or WGA did not influence the CE-2 biofilms on the SS coupons. Furthermore, treatment with cellulase, an enzyme specific for the degradation of beta 1-4 linked polymers, removed substantial amounts of CE-2 biofilm from SS coupons. These results strongly suggest the involvement of beta 1-4 linked polymers in the formation and maintenance of Pseudomonas sp. CE-2 biofilms on SS coupons.

Mineralization of a Malaysian crude oil by Pseudomonas sp. and Achromabacter sp. isolated from coastal waters

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

Ahmad, J.; Ahmad, M.F.

1995-12-31

Regarded as being a potentially effective tool to combat oil pollution, bioremediation involves mineralization, i.e., the conversion of complex hydrocarbons into harmless CO{sub 2} and water by action of microorganisms. Therefore, in achieving optimum effectiveness from the application of these products on crude oil in local environments, the capability of the bacteria to mineralize hydrocarbons was evaluated. The microbial laboratory testing of mineralization on local oil degraders involved, first, isolation of bacteria found at a port located on the west coast of Peninsular Malaysia. Subsequently, these bacteria were identified by means of Biomereux`s API 20E and 20 NE systems andmore » later screened by their growth on a Malaysian crude oil. Selected strains of Pseudomonas sp. and Achromabacter sp. were then exposed individually to a similar crude oil in a mineralization unit and monitored for 16 days for release of CO{sub 2}. Pseudomonas paucimobilis was found to produce more CO{sub 2} than Achromobacter sp. When tested under similar conditions, mixed populations of these two taxa produced more CO{sub 2} than that produced by any individual strain. Effective bioremediation of local crude in Malaysian waters can therefore be achieved from biochemically developed Pseudomonas sp. strains.« less

Differences in otosclerotic and normal human stapedial osteoblast properties are normalized by alendronate in vitro.

PubMed

Gronowicz, Gloria; Richardson, Yvonne L; Flynn, John; Kveton, John; Eisen, Marc; Leonard, Gerald; Aronow, Michael; Rodner, Craig; Parham, Kourosh

2014-10-01

Identify and compare phenotypic properties of osteoblasts from patients with otosclerosis (OSO), normal bones (HOB), and normal stapes (NSO) to determine a possible cause for OSO hypermineralization and assess any effects of the bisphosphonate, alendronate. OSO (n = 11), NSO (n = 4), and HOB (n = 13) cultures were assayed for proliferation, adhesion, mineralization, and gene expression with and without 10(-10)M-10(-8)M alendronate. Academic hospital. Cultures were matched for age, sex, and passage number. Cell attachment and proliferation + alendronate were determined by Coulter counting cells and assaying tritiated thymidine uptake, respectively. At 7, 14, and 21 days of culture + alendronate, calcium content and gene expression by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were determined. OSO had significantly more cells adhere but less proliferation than NSO or HOB. Calcification was significantly increased in OSO compared to HOB and NSO. NSO and HOB had similar cell adhesion and proliferation rates. A dose-dependent effect of alendronate on OSO adhesion, proliferation, and mineralization was found, resulting in levels equal to NSO and HOB. All cultures expressed osteoblast-specific genes such as RUNX2, alkaline phosphatase, type I collagen, and osteocalcin. However, osteopontin was dramatically reduced, 9.4-fold at 14 days, in OSO compared to NSO. Receptor activator of nuclear factor κB ligand/osteoprotegerin (RANKL/OPG), important in bone resorption, was elevated in OSO with decreased levels of OPG levels. Alendronate had little effect on gene expression in HOB but in OSO increased osteopontin levels and decreased RANKL/OPG. OSO cultures displayed properties of hypermineralization due to decreased osteopontin (OPN) and also had increased RANKL/OPG, which were normalized by alendronate. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

Biodegradation of phthalic acid esters (PAEs) and in silico structural characterization of mono-2-ethylhexyl phthalate (MEHP) hydrolase on the basis of close structural homolog.

PubMed

Singh, Neha; Dalal, Vikram; Mahto, Jai Krishna; Kumar, Pravindra

2017-09-15

Three bacterial strains capable of degrading phthalates namely Pseudomonas sp. PKDM2, Pseudomonas sp. PKDE1 and Pseudomonas sp. PKDE2 were isolated and characterized for their degradative potential. These strains efficiently degraded 77.4%-84.4% of DMP, 75.0%-75.7% of DEP and 71.7%-74.7% of DEHP, initial amount of each phthalate is 500mgL -1 of each phthalate, after 44h of incubation. GC-MS results reveal the tentative DEHP degradation pathway, where hydrolases mediate the breakdown of DEHP to phthalic acid (PA) via an intermediate MEHP. MEHP hydrolase is a serine hydrolase which is involved in the reduction of the MEHP to PA. The predicted 3D model of MEHP hydrolase from Pseudomonas mosselii was docked with phthalate monoesters (PMEs) such as MEHP, mono-n-hexyl phthalate (MHP), mono-n-butyl phthalate (MBP) and mono-n-ethyl phthalate (MEP), respectively. Docking results show the distance between the carbonyl carbon of respective phthalate monoester and the hydroxyl group of catalytic serine lies in the range of 2.9 to 3.3Å, which is similar to the ES complex of other serine hydrolases. This structural study highlights the interaction and the role of catalytic residues of MEHP hydrolase involved in the biodegradation of PMEs to phthalate. Copyright © 2017 Elsevier B.V. All rights reserved.

OXIDATION OF BIPHENYL BY A MULTICOMPONENT ENZYME SYSTEM FROM PSEUDOMONAS SP. STRAIN LB400

EPA Science Inventory

Pseudomonas sp. strain LB400 grows on biphenyl as the sole carbon and energy source. This organism also cooxidizes several chlorinated biphenyl congeners. Biphenyl dioxygenase activity in cell extract required addition of NAD(P)H as an electron donor for the conversion of bipheny...

Production of indole acetic acid by Pseudomonas sp.: effect of coinoculation with Mesorhizobium sp. Cicer on nodulation and plant growth of chickpea (Cicer arietinum).

PubMed

Malik, Deepak K; Sindhu, Satyavir S

2011-03-01

Pseudomonas isolates obtained from the rhizosphere of chickpea (Cicer arietinum L.) and green gram (Vigna radiata) were found to produce significant amount of indole acetic acid (IAA) when grown in a LB medium broth supplemented with L-tryptophan. Seed bacterization of chickpea cultivar C235 with different Pseudomonas isolates showed stunting effect on the development of root and shoot at 5 and 10 days of seedling growth except the strains MPS79 and MPS90 that showed stimulation of root growth, and strains MPS104 and MRS13 that showed shoot growth stimulation at 10 days. Exogenous treatment of seeds with IAA at 0.5 and 1.0 μM concentration caused similar stunting effects on root and shoot growth compared to untreated control both at 5 and 10 days of observation, whereas higher concentration of IAA (10.0 μM) inhibited the growth of seedlings. Coinoculation of chickpea with IAA-producing Pseudomonas strains increased nodule number and nodule biomass by Mesorhizobium sp. Cicer strain Ca181. The plant dry weights of coinoculated treatments showed 1.10 to 1.28 times increase in comparison to Mesorhizobium-inoculated plants alone and 3.62 to 4.50 times over uninoculated controls at 100 days of plant growth. The results indicated the potential usefulness of allelopathic rhizosphere bacteria and growth-mediating IAA in enhancement of nodulation and stimulation of plant growth in chickpea.

Isolation of a buprofezin co-metabolizing strain of Pseudomonas sp. DFS35-4 and identification of the buprofezin transformation pathway.

PubMed

Chen, Kai; Liu, Xiao-Mei; Li, Rong; Liu, Yuan; Hu, Hai; Li, Shun-Peng; Jiang, Jian-Dong

2011-11-01

Buprofezin is a widely used insecticide that has caused environmental pollution in many areas. However, biodegradation of buprofezin by pure cultures has not been extensively studied, and the transformation pathway of buprofezin remains unclear. In this paper, a buprofezin co-metabolizing strain of DFS35-4 was isolated from a buprofezin-polluted soil in China. Strain DFS35-4 was preliminarily identified as Pseudomonas sp. based on its morphological, physiological, and biochemical properties, as well as 16S rRNA gene analysis. In the presence of 2.0 g l(-1) sodium citrate, strain DFS35-4 degraded over 70% of 50 mg l(-1) buprofezin in 3 days. Strain DFS35-4 efficiently degraded buprofezin in the pH range of 5.0-10.0 and at temperatures between 20 and 30°C. Three metabolites, 2-imino-5-phenyl-3-(propan-2-yl)-1,3,5-thiadiazinan-4-one, 2-imino-5-phenyl-1,3,5-thiadiazinan-4-one, and methyl(phenyl) carbamic acid, were identified during the degradation of buprofezin using gas chromatography-mass spectrometry (GC-MS) and tandem mass spectrometry (MS/MS). A partial transformation pathway of buprofezin in Pseudomonas sp. DFS35-4 was proposed based on these metabolites.

Pseudomonas lutea sp. nov., a novel phosphate-solubilizing bacterium isolated from the rhizosphere of grasses.

PubMed

Peix, Alvaro; Rivas, Raúl; Santa-Regina, Ignacio; Mateos, Pedro F; Martínez-Molina, Eustoquio; Rodríguez-Barrueco, Claudino; Velázquez, Encarna

2004-05-01

A phosphate-solubilizing bacterial strain designated OK2(T) was isolated from rhizospheric soil of grasses growing spontaneously in a soil from Spain. Cells of the strain were Gram-negative, strictly aerobic, rod-shaped and motile. Phylogenetic analysis of the 16S rRNA gene indicated that this bacterium belongs to the gamma-subclass of Proteobacteria within the genus Pseudomonas and that the closest related species is Pseudomonas graminis. The strain produced catalase but not oxidase. Cellulose, casein, starch, gelatin and urea were not hydrolysed. Aesculin was hydrolysed. Growth was observed with many carbohydrates as carbon sources. The main non-polar fatty acids detected were hexadecenoic acid (16 : 1), hexadecanoic acid (16 : 0) and octadecenoic acid (18 : 1). The hydroxy fatty acids detected were 3-hydroxydecanoic acid (3-OH 10 : 0), 3-hydroxydodecanoic acid (3-OH 12 : 0) and 2-hydroxydodecanoic acid (2-OH 12 : 0). The G+C DNA content determined was 59.3 mol%. DNA-DNA hybridization showed 48.7 % relatedness between strain OK2(T) and P. graminis DSM 11363(T) and 26.2 % with respect to Pseudomonas rhizosphaerae LMG 21640(T). Therefore, these results indicate that strain OK2(T) (=LMG 21974(T)=CECT 5822(T)) belongs to a novel species of the genus Pseudomonas, and the name Pseudomonas lutea sp. nov. is proposed.

Sequence determination and analysis of three plasmids of Pseudomonas sp. GLE121, a psychrophile isolated from surface ice of Ecology Glacier (Antarctica).

PubMed

Dziewit, Lukasz; Grzesiak, Jakub; Ciok, Anna; Nieckarz, Marta; Zdanowski, Marek K; Bartosik, Dariusz

2013-09-01

Pseudomonas sp. GLE121 (a psychrophilic Antarctic strain) carries three plasmids: pGLE121P1 (6899 bp), pGLE121P2 (8330 bp) and pGLE121P3 (39,583 bp). Plasmids pGLE121P1 and pGLE121P2 show significant sequence similarity to members of the IncP-9 and IncP-7 incompatibility groups, respectively, while the largest replicon, pGLE121P3, is highly related to plasmid pNCPPB880-40 of Pseudomonas syringae pathovar tomato NCPPB880. All three plasmids have a narrow host range, limited to members of the genus Pseudomonas. Plasmid pGLE121P3 encodes a conjugal transfer system, while pGLE121P1 carries only a putative MOB module, conserved in many mobilizable plasmids. Plasmid pGLE121P3 contains an additional load of genetic information, including a pair of genes with homology to the rulAB operon, responsible for ultraviolet radiation (UVR) tolerance. Given the increasing UV exposure in Antarctic regions, the expression of these genes is likely to be an important adaptive response. Copyright © 2013 Elsevier Inc. All rights reserved.

Biodegradation of 2,4-dichlorophenoxyacetic acid by bacteria with highly antibiotic-resistant pattern isolated from wheat field soils in Kurdistan, Iran.

PubMed

Karami, Solmaz; Maleki, Afshin; Karimi, Ebrahim; Poormazaheri, Helen; Zandi, Shiva; Davari, Behrooz; Salimi, Yahya Zand; Gharibi, Fardin; Kalantar, Enayatollah

2016-12-01

Recently, there has been increasing interest to clean up the soils contaminated with herbicide. Our aim was to determine the bioremediation of 2,4-dichlorophenoxyacetic acid (2,4-D) from wheat fields which have a long history of herbicide in Sanandaj. Based on our literature survey, this study is the first report to isolate and identify antimicrobial resistant bacteria from polluted wheat field soils in Sanandaj which has the capacity to degrade 2,4-D. From 150 2,4-D-exposed soil samples, five different bacteria were isolated and identified based on biochemical tests and 16S ribosomal RNA (rRNA). Pseudomonas has been the most frequently isolated genus. By sequencing the 16S rRNA gene of the isolated bacteria, the strains were detected and identified as a member of the genus Pseudomonas sp, Entrobacter sp, Bacillus sp, Seratia sp, and Staphylococcus sp. The sequence of Sanandaj 1 isolate displayed 87% similarity with the 16S rRNA gene of a Pseudomonas sp (HE995788). Similarly, all the isolates were compared to standard strains based on 16S rRNA. Small amounts of 2,4-D could be transmitted to a depth of 10-20 cm; however, in the depth of 20-40 cm, we could not detect the 2,4-D. The isolates were resistant to various antibiotics particularly, penicillin, ampicillin, and amoxicillin.

Draft genome sequence of the novel strain Pseudomonas sp. 10B238 with potential ability to produce antibiotics from deep-sea sediment.

PubMed

Pan, Hua-Qi; Hu, Jiang-Chun

2015-10-01

Pseudomonas sp. 10B238 was a putatively novel species of Pseudomonas, isolated from a deep-sea sediment of the South China Sea, which had the genetic potential to produce secondary metabolites related to nonribosomal peptides (NRPs), as well as showed moderate antimicrobial activities. Here we report a high quality draft genome of Pseudomonas sp. 10B238, which comprises 4,933,052bp with the G+C content of 60.23%. A total of 11 potential secondary metabolite biosynthetic gene clusters were predicted, including a NRP for new peptide siderophore. And many anaerobic respiratory terminal enzymes were found for life in deep-sea environments. Our results may provide insights into biosynthetic pathway for antimicrobial bioactive compounds and be helpful to understand the physiological characteristic of this species. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution and survival of Pseudomonas sp. on Italian ryegrass and Curly dock in Georgia

USDA-ARS?s Scientific Manuscript database

Yellow bud, caused by Pseudomonas sp. is an emerging bacterial disease of onion. Polymerase chain reaction (PCR) assay based on the coronafacate ligase (cfl) and HrpZ genes were used to detect initial suspected bacteria on weeds. Growth on an agar medium, ability to cause a hypersensitive response i...

Sex-related differences in the thanatomicrobiome in postmortem heart samples using bacterial gene regions V1-2 and V4.

PubMed

Bell, Courtnee R; Wilkinson, Jeremy E; Robertson, Boakai K; Javan, Gulnaz T

2018-05-10

Recent studies have revealed distinct thanatomicrobiome (microbiome of death) signatures in human body sites after death. Thanatomicrobiome studies suggest that microbial succession after death may have the potential to reveal important postmortem biomarkers for the identification of time of death. We surveyed the postmortem microbiomes of cardiac tissues from ten corpses with varying times of death (6-58 h) using amplicon-based sequencing of the 16S rRNA gene' V1-2 and V4 hypervariable regions. The results demonstrated that amplicons had statistically significant (p <0.05) sex-dependent changes. Clostridium sp., Pseudomonas sp., Pantoea sp., and Streptococcus sp. had the highest enrichment for both V1-2 and V4 regions. Interestingly, the results also show that V4 amplicons had higher abundance of Clostridium sp. and Pseudomonas sp. in female hearts compared to males. Additionally, Streptococcus sp. was solely found in male heart samples. The distinction between sexes was further supported by Principle Coordinate Analysis, which revealed microbes in female hearts formed a distinctive cluster separate from male cadavers for both hypervariable regions. This study provides data that demonstrates that two hypervariable regions show discriminatory power for sex differences in postmortem heart samples. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pseudomonas rhizosphaerae sp. nov., a novel species that actively solubilizes phosphate in vitro.

PubMed

Peix, Alvaro; Rivas, Raúl; Mateos, Pedro F; Martínez-Molina, Eustoquio; Rodríguez-Barrueco, Claudino; Velázquez, Encarna

2003-11-01

A bacterial strain (designated IH5(T)), isolated from rhizospheric soil of grasses growing spontaneously in Spanish soil, actively solubilized phosphates in vitro when bicalcium phosphate was used as a phosphorus source. This strain was Gram-negative, strictly aerobic, rod-shaped and motile. The strain produced catalase, but not oxidase. Cellulose, casein, starch, gelatin, aesculin and urea were not hydrolysed. Growth was observed with many carbohydrates as the carbon source. The main non-polar fatty acids detected were hexadecenoic acid (C(16 : 1)), hexadecanoic acid (C(16 : 0)) and octadecenoic acid (C(18 : 1)). The hydroxy fatty acids detected were 3-hydroxydecanoic acid (C(10 : 0) 3-OH), 3-hydroxydodecanoic acid (C(12 : 0) 3-OH) and 2-hydroxydodecanoic acid (C(12 : 0) 2-OH). Phylogenetic analysis of 16S rRNA indicated that this bacterium belongs to the genus Pseudomonas in the gamma-subclass of the Proteobacteria and that the closest related species is Pseudomonas graminis. The DNA G+C content was 61 mol%. DNA-DNA hybridization showed 23 % relatedness between strain IH5(T) and P. graminis DSM 11363(T). Therefore, strain IH5(T) belongs to a novel species from the genus Pseudomonas, for which the name Pseudomonas rhizosphaerae sp. nov. is proposed (type strain, IH5(T)=LMG 21640(T)=CECT 5726(T)).

Pseudomonas aestus sp. nov., a plant growth-promoting bacterium isolated from mangrove sediments.

PubMed

Vasconcellos, Rafael L F; Santos, Suikinai Nobre; Zucchi, Tiago Domingues; Silva, Fábio Sérgio Paulino; Souza, Danilo Tosta; Melo, Itamar Soares

2017-10-01

Strain CMAA 1215 T , a Gram-reaction-negative, aerobic, catalase positive, polarly flagellated, motile, rod-shaped (0.5-0.8 × 1.3-1.9 µm) bacterium, was isolated from mangrove sediments, Cananéia Island, Brazil. Analysis of the 16S rRNA gene sequences showed that strain CMAA 1215 T forms a distinct phyletic line within the Pseudomonas putida subclade, being closely related to P. plecoglossicida ATCC 700383 T , P. monteilii NBRC 103158 T , and P. taiwanensis BCRC 17751 T of sequence similarity of 98.86, 98.73, and 98.71%, respectively. Genomic comparisons of the strain CMAA 1215 T with its closest phylogenetic type strains using average nucleotide index (ANI) and DNA:DNA relatedness approaches revealed 84.3-85.3% and 56.0-63.0%, respectively. A multilocus sequence analysis (MLSA) performed concatenating 16S rRNA, gyrB and rpoB gene sequences from the novel species was related with Pseudomonas putida subcluster and formed a new phylogenetic lineage. The phenotypic, physiological, biochemical, and genetic characteristics support the assignment of CMAA 1215 T to the genus Pseudomonas, representing a novel species. The name Pseudomonas aestus sp.nov. is proposed, with CMAA 1215 T (=NRRL B-653100 T  = CBMAI 1962 T ) as the type strain.

Influence of water-miscible cutting fluid on tool wear behavior of various coated high-speed steel tools in hobbing

NASA Astrophysics Data System (ADS)

Sato, Yuta; Matsuoka, Hironori; Kubo, Akio; Ono, Hajime; Ryu, Takahiro; Qiu, Hua; Nakae, Takashi; Shuto, Shuichi; Watanabe, Suguru; Anan, Ruito

2017-04-01

This paper deals with the influence of water-miscible cutting fluid on tool life (flank wear) compared with that with dry cutting and water-insoluble cutting oil in hobbing. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The following results were clarified. (1) The water-miscible cutting fluid used in the test prolongs the tool life for TiN-, TiAlN-, TiSiN- and AlCrSiN-coated tools in comparison with that obtained by dry cutting and water-insoluble cutting oil. (2) It was presumed that the tool wear decreases and the tool life is improved by the lubrication effect of the synthetic lubrication additive, mineral oil and sulfuric EP additive contained in the water-miscible cutting fluid, and also by the cooling effect.

Pseudomonas sp. BUP6, a novel isolate from Malabari goat produces an efficient rhamnolipid type biosurfactant.

PubMed

Priji, Prakasan; Sajith, Sreedharan; Unni, Kizhakkepowathial Nair; Anderson, Robin C; Benjamin, Sailas

2017-01-01

This study describes the characteristics of a biosurfactant produced by Pseudomonas sp. BUP6, a rumen bacterium, and optimization of parameters required for its production. Initial screening of five parameters (pH, temperature, agitation, incubation, and substrate concentration) was carried out employing Plackett-Burman design, which reduced the number of parameters to 3 (pH, temperature, and incubation) according to their significance on the yield of biosurfactant. A suitable statistical model for the production of biosurfactant by Pseudomonas sp. BUP6 was established according to Box-Behnken design, which resulted in 11% increase (at pH 7, 35 °C, incubation 75 h) in the yield (2070 mg L -1 ) of biosurfactant. The biosurfactant was found stable at a wide range of pH (3-9) with 48 mg L -1 critical micelle concentration; and maintained over 90% of its emulsification ability even after boiling and in presence of sodium chloride (0.5%). The highest cell hydrophobicity (37%) and emulsification (69%) indices were determined with groundnut oil and kerosene, respectively. The biosurfactant was found to inhibit the growth and adhesion of E. coli and S. aureus significantly. From the phytotoxicity studies, the biosurfactant did not show any adverse effect on the germinating seeds of rice and green gram. The structural characterization of biosurfactant employing orcinol method, thin layer chromatography and FT-IR indicated that it is a rhamnolipid (glycolipid). Thus, Pseudomonas sp. BUP6, a novel isolate from Malabari goat is demonstrated as a producer of an efficient rhamnolipid type biosurfactant suitable for application in various industries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Degradation of 4-chloro-3-nitrophenol via a novel intermediate, 4-chlororesorcinol by Pseudomonas sp. JHN

PubMed Central

Arora, Pankaj Kumar; Srivastava, Alok; Singh, Vijay Pal

2014-01-01

A 4-chloro-3-nitrophenol (4C3NP)-mineralizing bacterium, Pseudomonas sp. JHN was isolated from a waste water sample collected from a chemically-contaminated area, India by an enrichment method. Pseudomonas sp. JHN utilized 4C3NP as a sole carbon and energy source and degraded it with the release of stoichiometric amounts of chloride and nitrite ions. Gas chromatography and gas chromatography-mass spectrometry detected 4-chlororesorcinol as a major metabolite of the 4C3NP degradation pathway. Inhibition studies using 2,2′-dipyridyl showed that 4-chlororesorcinol is a terminal aromatic compound in the degradation pathway of 4C3NP. The activity for 4C3NP-monooxygenase was detected in the crude extracts of the 4C3NP-induced JHN cells that confirmed the formation of 4-chlororesorcinol from 4C3NP. The capillary assay showed that Pseudomonas sp. JHN exhibited chemotaxis toward 4C3NP. The bioremediation capability of Pseudomonas sp. JHN was monitored to carry out the microcosm experiments using sterile and non-sterile soils spiked with 4C3NP. Strain JHN degraded 4C3NP in sterile and non-sterile soil with same degradation rates. This is the first report of (i) bacterial degradation and bioremediation of 4C3NP, (ii) formation of 4-chlororesorcinol in the degradation pathway of 4C3NP, (iii) bacterial chemotaxis toward 4C3NP. PMID:24667329

Interspecific cooperation: enhanced growth, attachment and strain-specific distribution in biofilms through Azospirillum brasilense-Pseudomonas protegens co-cultivation.

PubMed

Pagnussat, Luciana A; Salcedo, Florencia; Maroniche, Guillermo; Keel, Christoph; Valverde, Claudio; Creus, Cecilia M

2016-10-01

Plant-growth-promoting bacteria belonging to Azospirillum and Pseudomonas genera are major inhabitants of the rhizosphere. Both are increasingly commercialized as crops inoculants. Interspecific interaction in the rhizosphere is critical for inoculants aptness. The objective of this work was to evaluate Azospirillum and Pseudomonas interaction in mixed biofilms by co-cultivation of the model strains Azospirillum brasilense Sp245 and Pseudomonas protegens CHA0. The results revealed enhanced growth of both strains when co-cultured in static conditions. Moreover, Sp245 biofilm formed in plastic surfaces was increased 2-fold in the presence of CHA0. Confocal microscopy revealed highly structured mixed biofilms showing Sp245 mainly on the bottom and CHA0 towards the biofilm surface. In addition, A. brasilense biofilm was thicker and denser when co-cultured with P. protegens. In a colony-colony interaction assay, Sp245 changed nearby CHA0 producing small colony phenotype, which accounts for a diffusible metabolite mediator; though CHA0 spent medium did not affect Sp245 colony phenotype. Altogether, these results point to a cooperative interaction between A. brasilense Sp245 and P. protegens CHA0 in which both strains increase their static growth and produce structured mixed biofilms with a strain-specific distribution. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Enhanced cometabolic degradation of methyl tert-butyl ether by a Pseudomonas sp. strain grown on n-pentane

NASA Astrophysics Data System (ADS)

Li, S. S.; Wang, S.; Yan, W.

2016-08-01

When methyl tert-butyl ether (MTBE) is added as oxygenates it increases the octane number and decreases the release of nitric oxide from the incomplete combustion of reformulated gasoline. The extensive use of MTBE allowed it to be detectable as a pollutant in both ground-level and underground water worldwide. The present study focuses on the isolation and characterization of MTB-degrading microorganisms by cometabolism based on the results of growth on different carbon sources. It also focuses on the kinetic analysis and the continuous degradation of MTBE. A bacterial strain WL1 that can grow on both n-alkanes (C5-C8) and aromatics was isolated and named Pseudomonas sp. WL1 according to the 16S rDNA sequencing analysis. Strain WL1 could cometabolically degrade MTBE in the presence of n-alkanes with a desirable degradation rate. Diverse n-alkanes with different lengths of carbon chains showed significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA). When strain WL1 cometabolically degraded MTBE in the presence of n-pentane, higher MTBE-degrading rate and lower TBA-accumulation were observed (Vmax = 38.1 nmol/min/mgprotei, Ks = 6.8 mmol/L). In the continuous degrading experiment, the removal efficiency of MTBE by Pseudomonas sp. WL1 did not show any obvious decrease after five subsequent additions.

Description of chlorophenol-degrading Pseudomonas sp. strains KF1T, KF3, and NKF1 as a new species of the genus Sphingomonas, Sphingomonas subarctica sp. nov.

PubMed

Nohynek, L J; Nurmiaho-Lassila, E L; Suhonen, E L; Busse, H J; Mohammadi, M; Hantula, J; Rainey, F; Salkinoja-Salonen, M S

1996-10-01

Gram-negative polychlorophenol-degrading bacterial strains KF1T (T = type strain), KF3, and NKF1, which were described previously as Pseudomonas saccharophila strains, were studied by chemotaxonomic, genetic, and physiological methods and by electron microscopy and compared with selected xenobiotic compound-degrading bacteria. These strains contained sphingolipids with d-18:0, d-20:1, and d-21:1 as the main dihydrosphingosines, ubiquinone 10 as the main respiratory quinone, and spermidine as the major polyamine, and the DNA G + C content was 66 mol%. The cellular fatty acids included about 60% octadecenoic acid, 9% 2-hydroxymyristic acid, 14% cis-9-hexadecenoic acid, and 10% hexadecanoic acid. These strains exhibited less than 97% 16S ribosomal DNA sequence similarity to all of the other taxa studied. In the DNA-DNA reassociation studies the highest levels of reassociation between these strains and previously described species were less than 40%. Thin sections of cells of strains KF1T, KF3, and NKF1 were examined by electron microscopy, and the results showed that the cells had peculiar concentrically arranged layered membranous blebs that extruded from the outer membrane, especially at the cell division points. On the basis of the results of this study, polychlorophenol-degrading strains KF1T, KF3, and NKF1 are considered members of a new species of the genus Sphingomonas, Sphingomonas subarctica. The polycyclic aromatic hydrocarbon-degrading organism Sphingomonas paucimobilis EPA 505 was closely related to Sphingomonas chlorophenolica as determined by chemotaxonomic, phylogenetic, and physiological criteria. The xenobiotic compound degraders Alcaligenes sp. strain A175 and Pseudomonas sp. strain BN6 were identified as members of species of the genus Sphingomonas.

Diverse Responses to UV-B Radiation and Repair Mechanisms of Bacteria Isolated from High-Altitude Aquatic Environments▿

PubMed Central

Fernández Zenoff, V.; Siñeriz, F.; Farías, M. E.

2006-01-01

Acinetobacter johnsonii A2 isolated from the natural community of Laguna Azul (Andean Mountains at 4,560 m above sea level), Serratia marcescens MF42, Pseudomonas sp. strain MF8 isolated from the planktonic community, and Cytophaga sp. strain MF7 isolated from the benthic community from Laguna Pozuelos (Andean Puna at 3,600 m above sea level) were subjected to UV-B (3,931 J m−2) irradiation. In addition, a marine Pseudomonas putida strain, 2IDINH, and a second Acinetobacter johnsonii strain, ATCC 17909, were used as external controls. Resistance to UV-B and kinetic rates of light-dependent (UV-A [315 to 400 nm] and cool white light [400 to 700 nm]) and -independent reactivation following exposure were determined by measuring the survival (expressed as CFU) and accumulation of cyclobutane pyrimidine dimers (CPD). Significant differences in survival after UV-B irradiation were observed: Acinetobacter johnsonii A2, 48%; Acinetobacter johnsonii ATCC 17909, 20%; Pseudomonas sp. strain MF8, 40%; marine Pseudomonas putida strain 2IDINH, 12%; Cytophaga sp. strain MF7, 20%; and Serratia marcescens, 21%. Most bacteria exhibited little DNA damage (between 40 and 80 CPD/Mb), except for the benthic isolate Cytophaga sp. strain MF7 (400 CPD/Mb) and Acinetobacter johnsonii ATCC 17909 (160 CPD/Mb). The recovery strategies through dark and light repair were different in all strains. The most efficient in recovering were both Acinetobacter johnsonii A2 and Cytophaga sp. strain MF7; Serratia marcescens MF42 showed intermediate recovery, and in both Pseudomonas strains, recovery was essentially zero. The UV-B responses and recovery abilities of the different bacteria were consistent with the irradiation levels in their native environment. PMID:17056692

Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents

PubMed Central

Ghanbari, Raheleh; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Ismail, Amin; Saari, Nazamid

2012-01-01

Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH) were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp.) were evaluated. Papain hydrolysis showed the highest DH value (89.44%), followed by alcalase hydrolysis (83.35%). Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions. PMID:23222684

Experimental Comparison of Face-Milled and Face-Hobbed Spiral Bevel Gears

NASA Technical Reports Server (NTRS)

Handschuh, Robert F.; Nanlawala, Michael; Hawkins, John M.; Mahan, Danny

2001-01-01

An experimental comparison of face-milled and face-hobbed spiral bevel gears was accomplished. The two differently manufactured spiral bevel gear types were tested in a closed-loop facility at NASA Glenn Research Center. Strain, vibration, and noise testing were completed at various levels of rotational speed and load. Tests were conducted from static (slow-roll) to 12600 rpm and up to 269 N-m (2380 in.-lb) pinion speed and load conditions. The tests indicated that the maximum stress recorded at the root locations had nearly the same values, however the stress distribution was different from the toe to the heel. Also, the alternating stress measured was higher for the face-milled pinion than that attained for the face-hobbed pinion (larger minimum stress). The noise and vibration results indicated that the levels measured for the face-hobbed components were less than those attained for the face-milled gears tested.

Biosurfactant-producing microorganism Pseudomonas sp. SB assists the phytoremediation of DDT-contaminated soil by two grass species.

PubMed

Wang, Beibei; Wang, Qingling; Liu, Wuxing; Liu, Xiaoyan; Hou, Jinyu; Teng, Ying; Luo, Yongming; Christie, Peter

2017-09-01

Phytoremediation together with microorganisms may confer the advantages of both phytoremediation and microbial remediation of soils containing organic contaminants. In this system biosurfactants produced by Pseudomonas sp. SB may effectively help to increase the bioavailability of organic pollutants and thereby enhance their microbial degradation in soil. Plants may enhance the rhizosphere environment for microorganisms and thus promote the bioremediation of contaminants. In the present pot experiment study, dichlorodiphenyltrichloroethane (DDT) residues underwent an apparent decline after soil bioremediation compared with the original soil. The removal efficiency of fertilizer + tall fescue, fertilizer + tall fescue + Pseudomonas, fertilizer + perennial ryegrass, and fertilizer + perennial ryegrass + Pseudomonas treatments were 59.4, 65.6, 69.0, and 65.9%, respectively, and were generally higher than that in the fertilizer control (40.3%). Principal coordinates analysis (PCoA) verifies that plant species greatly affected the soil bacterial community irrespective of inoculation with Pseudomonas sp. SB. Furthermore, community composition analysis shows that Proteobacteria, Acidobacteria and Actinobacteria were the three dominant phyla in all groups. In particular, the relative abundance of Pseudomonas for fertilizer + tall fescue + Pseudomonas (0.25%) was significantly greater than fertilizer + tall fescue and this was related to the DDT removal efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Oxidative Formation and Removal of Complexed Mn(III) by Pseudomonas Species

PubMed Central

Wright, Mitchell H.; Geszvain, Kati; Oldham, Véronique E.; Luther, George W.; Tebo, Bradley M.

2018-01-01

The observation of significant concentrations of soluble Mn(III) complexes in oxic, suboxic, and some anoxic waters has triggered a re-evaluation of the previous Mn paradigm which focused on the cycling between soluble Mn(II) and insoluble Mn(III,IV) species as operationally defined by filtration. Though Mn(II) oxidation in aquatic environments is primarily bacterially-mediated, little is known about the effect of Mn(III)-binding ligands on Mn(II) oxidation nor on the formation and removal of Mn(III). Pseudomonas putida GB-1 is one of the most extensively investigated of all Mn(II) oxidizing bacteria, encoding genes for three Mn oxidases (McoA, MnxG, and MopA). P. putida GB-1 and associated Mn oxidase mutants were tested alongside environmental isolates Pseudomonas hunanensis GSL-007 and Pseudomonas sp. GSL-010 for their ability to both directly oxidize weakly and strongly bound Mn(III), and to form these complexes through the oxidation of Mn(II). Using Mn(III)-citrate (weak complex) and Mn(III)-DFOB (strong complex), it was observed that P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 and mutants expressing only MnxG and McoA were able to directly oxidize both species at varying levels; however, no oxidation was detected in cultures of a P. putida mutant expressing only MopA. During cultivation in the presence of Mn(II) and citrate or DFOB, P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 formed Mn(III) complexes transiently as an intermediate before forming Mn(III/IV) oxides with the overall rates and extents of Mn(III,IV) oxide formation being greater for Mn(III)-citrate than for Mn(III)-DFOB. These data highlight the role of bacteria in the oxidative portion of the Mn cycle and suggest that the oxidation of strong Mn(III) complexes can occur through enzymatic mechanisms involving multicopper oxidases. The results support the observations from field studies and further emphasize the complexity of the geochemical cycling of manganese. PMID:29706936

Oxidative Formation and Removal of Complexed Mn(III) by Pseudomonas Species.

PubMed

Wright, Mitchell H; Geszvain, Kati; Oldham, Véronique E; Luther, George W; Tebo, Bradley M

2018-01-01

The observation of significant concentrations of soluble Mn(III) complexes in oxic, suboxic, and some anoxic waters has triggered a re-evaluation of the previous Mn paradigm which focused on the cycling between soluble Mn(II) and insoluble Mn(III,IV) species as operationally defined by filtration. Though Mn(II) oxidation in aquatic environments is primarily bacterially-mediated, little is known about the effect of Mn(III)-binding ligands on Mn(II) oxidation nor on the formation and removal of Mn(III). Pseudomonas putida GB-1 is one of the most extensively investigated of all Mn(II) oxidizing bacteria, encoding genes for three Mn oxidases (McoA, MnxG, and MopA). P. putida GB-1 and associated Mn oxidase mutants were tested alongside environmental isolates Pseudomonas hunanensis GSL-007 and Pseudomonas sp. GSL-010 for their ability to both directly oxidize weakly and strongly bound Mn(III), and to form these complexes through the oxidation of Mn(II). Using Mn(III)-citrate (weak complex) and Mn(III)-DFOB (strong complex), it was observed that P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 and mutants expressing only MnxG and McoA were able to directly oxidize both species at varying levels; however, no oxidation was detected in cultures of a P. putida mutant expressing only MopA. During cultivation in the presence of Mn(II) and citrate or DFOB, P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 formed Mn(III) complexes transiently as an intermediate before forming Mn(III/IV) oxides with the overall rates and extents of Mn(III,IV) oxide formation being greater for Mn(III)-citrate than for Mn(III)-DFOB. These data highlight the role of bacteria in the oxidative portion of the Mn cycle and suggest that the oxidation of strong Mn(III) complexes can occur through enzymatic mechanisms involving multicopper oxidases. The results support the observations from field studies and further emphasize the complexity of the geochemical cycling of manganese.

THz+X Seedling Report

DTIC Science & Technology

2005-11-23

lamblia Entamoeba histolytica Toxoplasma Microsporidia Additional viral encephalitides West Nile Virus LaCrosse California encephalitis VEE...Is Catalyzed by Salicylate 1- Monooxygenase from Pseudomonas sp . Strain ATCC 29352; Applied and Environmental Microbiology, July 2004, p. 4040-4047...the Mechanism of RDX Biodegradation by Rhodococcus - 31 - sp . Strain DN22; Applied and Environmental Microbiology, March 2003, p. 1347-1351

A novel enterocin T1 with anti-Pseudomonas activity produced by Enterococcus faecium T1 from Chinese Tibet cheese.

PubMed

Liu, Hui; Zhang, Lanwei; Yi, Huaxi; Han, Xue; Gao, Wei; Chi, Chunliang; Song, Wei; Li, Haiying; Liu, Chunguang

2016-02-01

An enterocin-producing Enterococcus faecium T1 was isolated from Chinese Tibet cheese. The enterocin was purified by SP-Sepharose and reversed phase HPLC. It was identified as unique from other reported bacteriocins based on molecular weight (4629 Da) and amino acid compositions; therefore it was subsequently named enterocin T1. Enterocin T1 was stable at 80-100 °C and over a wide pH range, pH 3.0-10.0. Protease sensitivity was observed to trypsin, pepsin, papain, proteinase K, and pronase E. Importantly, enterocin T1 was observed to inhibit the growth of numerous Gram-negative and Gram-positive bacteria including Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas fluorescens, Escherichia coli, Salmonella typhimurium, Shigella flexneri, Shigella sonnei, Staphylococcus aureus, Listeria monocytogenes. Take together, these results suggest that enterocin T1 is a novel bacteriocin with the potential to be used as a bio-preservative to control Pseudomonas spp. in food.

Draft Genome Sequence of a Kale (Brassica oleracea L.) Root Endophyte, Pseudomonas sp. Strain C9.

PubMed

Laugraud, Aurelie; Young, Sandra; Gerard, Emily; O'Callaghan, Maureen; Wakelin, Steven

2017-04-13

Pseudomonas sp. strain C9 is a plant growth-promoting bacterium isolated from the root tissue of Brassica oleracea L. grown in soil from Marlborough, New Zealand. Its draft genome of 6,350,161 bp contains genes associated with plant growth promotion and biological control. Copyright © 2017 Laugraud et al.

Draft Genome Sequence of Pseudomonas sp. Strain LFM046, a Producer of Medium-Chain-Length Polyhydroxyalkanoate

PubMed Central

Cardinali-Rezende, Juliana; Alexandrino, Paulo Moises Raduan; Nahat, Rafael Augusto Theodoro Pereira de Souza; Sant’Ana, Débora Parrine Vieira; Silva, Luiziana Ferreira; Gomez, José Gregório Cabrera

2015-01-01

Pseudomonas sp. LFM046 is a medium-chain-length polyhydroxyalkanoate (PHAMCL) producer capable of using various carbon sources (carbohydrates, organic acids, and vegetable oils) and was first isolated from sugarcane cultivation soil in Brazil. The genome sequence was found to be 5.97 Mb long with a G+C content of 66%. PMID:26294616

Involvement of phenazines and biosurfactants in biocontrol of Pythium myriotylum root rot on cocoyam by Pseudomonas sp. CMR12A

USDA-ARS?s Scientific Manuscript database

Pseudomonas sp. CMR12a was isolated from the rhizosphere of the tropical tuber crop cocoyam and produces both phenazines and cyclic lipopeptide (CLP) biosurfactants. CMR12a was shown to be an efficient biocontrol agent of P. myriotylum on cocoyam. To assess the importance of phenazine and biosurfact...

Kinetics of styrene biodegradation by Pseudomonas sp. E-93486.

PubMed

Gąszczak, Agnieszka; Bartelmus, Grażyna; Greń, Izabela

2012-01-01

The research into kinetics of styrene biodegradation by bacterial strain Pseudomonas sp. E-93486 coming from VTT Culture Collection (Finland) was presented in this work. Microbial growth tests in the presence of styrene as the sole carbon and energy source were performed both in batch and continuous cultures. Batch experiments were conducted for initial concentration of styrene in the liquid phase changed in the range of 5-90 g m(-3). The Haldane model was found to be the best to fit the kinetic data, and the estimated constants of the equation were: μ (m) = 0.1188 h(-1), K(S) = 5.984 mg l(-1), and K (i) = 156.6 mg l(-1). The yield coefficient mean value [Formula in text] for the batch culture was 0.72 g(dry cells weight) (g(substrate))(-1). The experiments conducted in a chemostat at various dilution rates (D = 0.035-0.1 h(-1)) made it possible to determine the value of the coefficient for maintenance metabolism m (d) = 0.0165 h(-1) and the maximum yield coefficient value [Formula in text]. Chemostat experiments confirmed the high value of yield coefficient [Formula in text] observed in the batch culture. The conducted experiments showed high activity of the examined strain in the styrene biodegradation process and a relatively low sensitivity to inhibition of its growth at higher concentrations of styrene in the solution. Such exceptional features of Pseudomonas sp. E-93486 make this bacterial strain the perfect candidate for technical applications.

Characterization of bacterial isolates from rubber dump site and their use in biodegradation of isoprene in batch and continuous bioreactors.

PubMed

Srivastva, Navnita; Shukla, Awadhesh Kumar; Singh, Ram Sharan; Upadhyay, Siddh Nath; Dubey, Suresh Kumar

2015-01-01

Bacterial isolates from contaminated soil of a waste rubber dumping site were isolated and characterized using biochemical and molecular approaches. Isoprene degradation kinetics in batch mode (isoprene concentration: 100-1000 ppm) revealed the degradation efficiency of isolates as: Pseudomonas sp. (83%)>Alcaligenes sp. (70%)>Klebsiella sp. (68.5%). The most efficient isolate Pseudomonas sp. was finally inoculated in a specifically designed bioreactor system comprising a bioscrubber and a biofilter packed with polyurethane foam connected in series. The bioscrubber and biofilter units when operated in a series showed more than 90% removal efficiency up to the inlet loading rate (IL) of 371.1g/m(3)/h. Maximum elimination capacity (EC) of biofilter was found to be an order of magnitude greater than that for bioscrubber. Oxidative cleavage of the double bond of isoprene has been revealed through IR spectra of the leachate. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification of activities that catalyze the cis-trans isomerization of the double bond of a mono-unsaturated fatty acid in Pseudomonas sp. strain E-3.

PubMed

Okuyama, H; Enari, D; Shibahara, A; Yamamoto, K; Morita, N

1996-06-01

A cell-free extract of Pseudomonas sp. strain E-3 catalyzed the conversion of 9-cis-hexadecenoic acid [16:1(9c)] to 9-trans-hexadecenoic acid [16:1(9t)] in the free acid form and when 16:1(9c) was esterified to phosphatidylethanolamine (PE). The cytosolic fraction catalyzed the isomerizations of free 16:1(9c) by itself and of 16:1(9c) esterified to PE in the presence of the membrane fraction. Tracer experiments using [2,2-2H2]16:1(9c) demonstrated that the isomerization of free 16:1(9c) occurred independently of the isomerization of 16:1(9c) esterified to PE, indicating that this bacterium has two types of activities that catalyze the cis-trans isomerization of the double bond of a mono-unsaturated fatty acid.

Molecular detection of six (endo-) symbiotic bacteria in Belgian mosquitoes: first step towards the selection of appropriate paratransgenesis candidates.

PubMed

Raharimalala, Fara Nantenaina; Boukraa, S; Bawin, T; Boyer, S; Francis, F

2016-04-01

Actually, the use of symbiotic bacteria is one of alternative solution to avoid vector resistance to pesticides. In Belgium, among 31 identified mosquito species, 10 were considered as potential vectors. Given to introduction risks of arbovirosis, the purpose of this study was to investigate the presence of symbiosis bacteria in potential mosquito vectors. Eleven species caught from 12 sites in Belgium were used: Culex pipiens s.l., Culex torrentium, Culex hortensis, Anopheles claviger, Anopheles maculipennis s.l., Anopheles plumbeus, Culiseta annulata, Ochlerotatus geniculatus, Ochlerotatus dorsalis, Aedes albopictus, and Coquillettidia richiardii. Six genera of symbiotic bacteria were screened: Wolbachia sp., Comamonas sp, Delftia sp., Pseudomonas sp., Acinetobacter sp., and Asaia sp. A total of 173 mosquito individuals (144 larvae and 29 adults) were used for the polymerase chain reaction screening. Wolbachia was not found in any Anopheles species nor Cx. torrentium. A total absence of Comamonas and Delftia was observed in all species. Acinetobacter, Pseudomonas, and Asaia were found in most of species with a high prevalence for Pseudomonas. These results were discussed to develop potential strategy and exploit the variable occurrence of symbiotic bacteria to focus on them to propose biological ways of mosquito control.

Naphthalene degradation by bacterial consortium (DV-AL) developed from Alang-Sosiya ship breaking yard, Gujarat, India.

PubMed

Patel, Vilas; Jain, Siddharth; Madamwar, Datta

2012-03-01

Naphthalene degrading bacterial consortium (DV-AL) was developed by enrichment culture technique from sediment collected from the Alang-Sosiya ship breaking yard, Gujarat, India. The 16S rRNA gene based molecular analyzes revealed that the bacterial consortium (DV-AL) consisted of four strains namely, Achromobacter sp. BAB239, Pseudomonas sp. DV-AL2, Enterobacter sp. BAB240 and Pseudomonas sp. BAB241. Consortium DV-AL was able to degrade 1000 ppm of naphthalene in Bushnell Haas medium (BHM) containing peptone (0.1%) as co-substrate with an initial pH of 8.0 at 37°C under shaking conditions (150 rpm) within 24h. Maximum growth rate and naphthalene degradation rate were found to be 0.0389 h(-1) and 80 mg h(-1), respectively. Consortium DV-AL was able to utilize other aromatic and aliphatic hydrocarbons such as benzene, phenol, carbazole, petroleum oil, diesel fuel, and phenanthrene and 2-methyl naphthalene as sole carbon source. Consortium DV-AL was also efficient to degrade naphthalene in the presence of other pollutants such as petroleum hydrocarbons and heavy metals. Copyright © 2011 Elsevier Ltd. All rights reserved.

Metabolism of hexadecyltrimethylammonium chloride in Pseudomonas strain B1.

PubMed Central

van Ginkel, C G; van Dijk, J B; Kroon, A G

1992-01-01

A bacterium (strain B1) utilizing hexadecyltrimethylammonium chloride as a carbon and energy source was isolated from activated sludge and tentatively identified as a Pseudomonas sp. This bacterium only grew on alkyltrimethylammonium salts (C12 to C22) and possible intermediates of hexadecyltrimethylammonium chloride breakdown such as hexadecanoate and acetate. Pseudomonas strain B1 did not grow on amines. Simultaneous adaptation studies suggested that the bacterium oxidized only the alkyl chain of hexadecyltrimethylammonium chloride. This was confirmed by the stoichiometric formation of trimethylamine from hexadecyltrimethylammonium chloride. The initial hexadecyltrimethylammonium chloride oxygenase activity, measured by its ability to form trimethylamine, was NAD(P)H and O2 dependent. Finally, assays of aldehyde dehydrogenase, hexadecanoyl-coenzyme A dehydrogenase, and isocitrate lyase in cell extracts revealed the potential of Pseudomonas strain B1 to metabolize the alkyl chain via beta-oxidation. PMID:1444422

Degradation and metabolism of synthetic plastics and associated products by Pseudomonas sp.: capabilities and challenges.

PubMed

Wilkes, R A; Aristilde, L

2017-09-01

Synthetic plastics, which are widely present in materials of everyday use, are ubiquitous and slowly-degrading polymers in environmental wastes. Of special interest are the capabilities of microorganisms to accelerate their degradation. Members of the metabolically diverse genus Pseudomonas are of particular interest due to their capabilities to degrade and metabolize synthetic plastics. Pseudomonas species isolated from environmental matrices have been identified to degrade polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, polyethylene terephthalate, polyethylene succinate, polyethylene glycol and polyvinyl alcohol at varying degrees of efficiency. Here, we present a review of the current knowledge on the factors that control the ability of Pseudomonas sp. to process these different plastic polymers and their by-products. These factors include cell surface attachment within biofilms, catalytic enzymes involved in oxidation or hydrolysis of the plastic polymer, metabolic pathways responsible for uptake and assimilation of plastic fragments and chemical factors that are advantageous or inhibitory to the biodegradation process. We also highlight future research directions required in order to harness fully the capabilities of Pseudomonas sp. in bioremediation strategies towards eliminating plastic wastes. © 2017 The Society for Applied Microbiology.

Draft Genome Sequence of Pseudomonas sp. Strain JMM, a Sediment-Hosted Environmental Isolate

PubMed Central

Grewal, Simmi; Vakhlu, Jyoti; Gupta, Vipin; Sangwan, Naseer; Kohli, Puneet; Nayyar, Namita; Rani, Pooja; Sance, Shivani Singh

2014-01-01

Pseudomonas sp. strain JMM was isolated from the sediments of a natural water reservoir (pH, 6 to 7) located at Chambyal village in Samba district of Jammu and Kashmir, India. Here we report the annotated draft genome sequence of strain JMM having 52 contigs with 5,884 genes and an average G+C content of 66.5%. PMID:25189587

Effects of zoledronic acid and geranylgeraniol on the cellular behaviour and gene expression of primary human alveolar osteoblasts.

PubMed

Zafar, S; Coates, D E; Cullinan, M P; Drummond, B K; Milne, T; Seymour, G J

2016-11-01

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious complication of bisphosphonate therapy. The mechanism underlying BRONJ pathogenesis is poorly understood. To determine the effects of zoledronic acid (ZA) and geranylgeraniol (GGOH) on the mevalonate pathway (MVP) in osteoblasts generated from the human mandibular alveolar bone in terms of cell viability/proliferation, migration, apoptosis and gene expression. Primary human osteoblasts (HOBs) isolated from the mandibular alveolar bone were phenotyped. HOBs were cultured with or without ZA and GGOH for up to 72 h. Cellular behaviour was examined using a CellTiter-Blue® viability assay, an Ibidi culture-insert migration assay, an Apo-ONE® Homogeneous Caspase-3/7 apoptosis assay and transmission electron microscopy (TEM). Quantitative real-time reverse transcriptase polymerase chain reaction (qRT 2 -PCR) was used to determine the simultaneous expression of 168 osteogenic and angiogenic genes modulated in the presence of ZA and GGOH. ZA decreased cell viability and migration and induced apoptosis in HOBs. TEM revealed signs of apoptosis in ZA-treated HOBs. However, the co-addition of GGOH ameliorated the effect of ZA and partially restored the cells to the control state. Twenty-eight genes in the osteogenic array and 27 genes in the angiogenic array were significantly regulated in the presence of ZA compared with those in the controls at one or more time points. The cytotoxic effect of ZA on HOBs and its reversal by the addition of GGOH suggests that the effect of ZA on HOBs is mediated via the MVP. The results suggest that GGOH could be used as a possible therapeutic/preventive strategy for BRONJ.

Recruitment of a chromosomally encoded maleylacetate reductase for degradation of 2,4-dichlorophenoxyacetic acid by plasmid pJP4.

PubMed Central

Kukor, J J; Olsen, R H; Siak, J S

1989-01-01

When Pseudomonas aeruginosa PAO1c or P. putida PPO200 or PPO300 carry plasmid pJP4, which encodes enzymes for the degradation of 2,4-dichlorophenoxyacetic acid (TFD) to 2-chloromaleylacetate, cells do not grow on TFD and UV-absorbing material with spectral characteristics of chloromaleylacetate accumulates in the culture medium. Using plasmid pRO1727, we cloned from the chromosome of a nonfluorescent pseudomonad, Pseudomonas sp. strain PKO1, 6- and 0.5-kilobase BamHI DNA fragments which contain the gene for maleylacetate reductase. When carrying either of the recombinant plasmids, pRO1944 or pRO1945, together with pJP4, cells of P. aeruginosa or P. putida were able to utilize TFD as a sole carbon source for growth. A novel polypeptide with an estimated molecular weight of 18,000 was detected in cell extracts of P. aeruginosa carrying either plasmid pRO1944 or plasmid pRO1945. Maleylacetate reductase activity was induced in cells of P. aeruginosa or P. putida carrying plasmid pRO1945, as well as in cells of Pseudomonas strain PKO1, when grown on L-tyrosine, suggesting that the tyrosine catabolic pathway might be the source from which maleylacetate reductase is recruited for the degradation of TFD in pJP4-bearing cells of Pseudomonas sp. strain PKO1. Images PMID:2722753

Metal resistance mechanisms in Gram-negative bacteria and their potential to remove Hg in the presence of other metals.

PubMed

Giovanella, Patricia; Cabral, Lucélia; Costa, Alexandre Pereira; de Oliveira Camargo, Flávio Anastácio; Gianello, Clesio; Bento, Fátima Menezes

2017-06-01

Contamination of the environment by heavy metals has been increasing in recent years due to industrial activities. Thus research involving microorganisms capable of surviving in multi-contaminated environments is extremely important. The objectives of the present study were to evaluate the removal of mercury alone and in the presence of cadmium, nickel and lead by four mercury-resistant microorganisms; estimate the removal of Cd, Ni and Pb; understand the mechanisms involved (reduction, siderophores, biofilms, biosorption and bioaccumulation) in the metal resistance of the isolate Pseudomonas sp. B50D; and determine the capacity of Pseudomonas sp. B50D in removing Hg, Cd, Ni and Pb from an industrial effluent. It was shown that the four isolates evaluated were capable of removing from 62% to 95% of mercury from a culture medium with no addition of other metals. The isolate Pseudomonas sp. B50D showed the best performance in the removal of mercury when evaluated concomitantly with other metals. This isolate was capable of removing 75% of Hg in the presence of Cd and 91% in the presence of Ni and Pb. With respect to the other metals it removed 60%, 15% and 85% of Cd, Ni and Pb, respectively. In tests with effluent, the isolate Pseudomonas sp. B50D removed 85% of Hg but did not remove the other metals. This isolate presented reduction, biosorption, biofilm production and siderophore production as its metal resistance mechanisms. Pseudomonas sp. B50D was thus a candidate with potential for application in the bioremediation of effluents with complex metal contaminations. Copyright © 2017 Elsevier Inc. All rights reserved.

Far from superficial: microbial diversity associated with the skin and mucus of fish

USGS Publications Warehouse

Cipriano, Rocco C.; Dove, Alistair; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

2011-01-01

During horizontal or water-borne infection involving an obligate pathogen (e.g. – Aeromonas salmonicida, cause of furunculosis), the pathogen interacted with and influenced the microbial diversity of the dermal mucus of fish. Prior to infection, the prevalent bacterial flora cultured from juvenile Atlantic salmon (Salmo salar) included Pseudomonas fluorescens, Comomonas terrigenia, Acinetobacter sp., Moraxella sp., Pseudomonas dimunita, Alcaligenes denitrificans, Pseudomonas pseudoalcaligenes, and Pseudomonas alcaligenes, Serratia liquefaciens, Aeromonas hydrophila, other motile Aeromonas spp., and Corynebacterium aquaticum. After A. salmonicida was initially detected in this population as an external mucus infection, Acinetobacter sp., Moraxella sp., C. terrigenia, P. fluorescens, and P. dimunita, Staphylococcus sp., and A. hydrophila, were also present in appreciable numbers. Within several weeks, however, the A. salmonicida infection amplified and composed 78% of the total flora in the mucus. Only P. dimunita (4%). P. fluorescens (2%), and C. terrigenia (1%) were cultured at that time and more than a third of these fish showed evidence of a systemic A. salmonicida infection within their kidneys. Eight weeks after oral oxytetracycline treatments, A. salmonicida was no longer isolated from the mucus or kidneys of any fish and glucose inert or other oxidative microbes (e.g., P. fluorescens, C. terrigenia, Acinetobacter sp., Moraxella sp.) were beginning to repopulate the external surface of the salmon in increasing frequency. Still present and composing fairly large percentages of the total flora were A. hydrophila, as well as Enterobacter sp., and P. putrefaciens. A normal microbial diversity was re-established as the fish recovered. In another investigation, reduced biological diversity was noted in the dermal mucus among smallmouth bass that were sampled from the Jackson River (Covington, VA). In these fish, A. hydrophila and P. putrefaciens were the two predominant microorganisms composing 49.5% and 31.2% of the total bacterial flora, despite the absence of systemic infection or any other clinical signs of disease. In another instance, P. fluorescens was the sole bacterium associated with the surface of Atlantic salmon eggs regardless of their viability at the eyed stage of development. Collectively, these results indicate that the kinetics and distributions of the surface bacterial flora on aquatic organisms is affected by numerous factors including pathogen invasion, environmental conditions, and fish culture practices.

Infections caused by pathogenic free-living amebas (Balamuthia mandrillaris and Acanthamoeba sp.) in horses.

PubMed

Kinde, Hailu; Read, Deryck H; Daft, Barbara M; Manzer, Michael; Nordhausen, Robert W; Kelly, Daryl J; Fuerst, Paul A; Booton, Gregory; Visvesvara, Govinda S

2007-05-01

This article describes amebic infections in 4 horses: granulomatous amebic encephalitis caused by Balamuthia mandrillaris and Acanthamoeba culbertsoni and systemic infections caused by Acanthamoeba sp. The former infection occurred in 1 of 4 horses spontaneously without any underlying conditions; the latter amebic infection was perhaps "opportunistic" considering the visceral involvement by this protozoan in association with Aspergillus sp. and/or Escherichia coli and Pseudomonas sp. The clinicopathologic findings and demonstration of the amebic organisms using immunohistochemical techniques, culture, polymerase chain reactions, and electron microscopy are presented.

Biological control of fusarium seedling blight disease of wheat and barley.

PubMed

Khan, Mojibur R; Fischer, Sven; Egan, Damian; Doohan, Fiona M

2006-04-01

ABSTRACT Fusarium fungi, including F. culmorum, cause seedling blight, foot rot, and head blight diseases of cereals, resulting in yield loss. In a screen for potential disease control organisms and agents, Pseudomonas fluorescens strains MKB 100 and MKB 249, P. frederiksbergensis strain 202, Pseudomonas sp. strain MKB 158, and chitosan all significantly reduced the extent of both wheat coleoptile growth retardation and wheat and barley seedling blight caused by F. culmorum (by 53 to 91%). Trichodiene synthase is a Fusarium enzyme necessary for trichothecene mycotoxin biosynthesis; expression of the gene encoding this enzyme in wheat was 33% lower in stem base tissue coinoculated with Pseudomonas sp. strain MKB 158 and F. culmorum than in wheat treated with bacterial culture medium and F. culmorum. When wheat and barley were grown in soil amended with either chitosan, P. fluorescens strain MKB 249, Pseudomonas sp. strain MKB 158, or culture filtrates of these bacteria, the level of disease symptoms on F. culmorum-inoculated stem base tissue (at 12 days post- F. culmorum inoculation) was >/=31% less than the level on F. culmorum-inoculated plants grown in culture medium-amended soil. It seems likely that at least part of the biocontrol activity of these bacteria and chitosan may be due to the induction of systemic disease resistance in host plants. Also, in coinoculation studies, Pseudomonas sp. strain MKB 158 induced the expression of a wheat class III plant peroxidase gene (a pathogenesis-related gene).

Regulatory Feedback Loop of Two phz Gene Clusters through 5′-Untranslated Regions in Pseudomonas sp. M18

PubMed Central

Li, Yaqian; Du, Xilin; Lu, Zhi John; Wu, Daqiang; Zhao, Yilei; Ren, Bin; Huang, Jiaofang; Huang, Xianqing; Xu, Yuhong; Xu, Yuquan

2011-01-01

Background Phenazines are important compounds produced by pseudomonads and other bacteria. Two phz gene clusters called phzA1-G1 and phzA2-G2, respectively, were found in the genome of Pseudomonas sp. M18, an effective biocontrol agent, which is highly homologous to the opportunistic human pathogen P. aeruginosa PAO1, however little is known about the correlation between the expressions of two phz gene clusters. Methodology/Principal Findings Two chromosomal insertion inactivated mutants for the two gene clusters were constructed respectively and the correlation between the expressions of two phz gene clusters was investigated in strain M18. Phenazine-1-carboxylic acid (PCA) molecules produced from phzA2-G2 gene cluster are able to auto-regulate expression itself and activate the expression of phzA1-G1 gene cluster in a circulated amplification pattern. However, the post-transcriptional expression of phzA1-G1 transcript was blocked principally through 5′-untranslated region (UTR). In contrast, the phzA2-G2 gene cluster was transcribed to a lesser extent and translated efficiently and was negatively regulated by the GacA signal transduction pathway, mainly at a post-transcriptional level. Conclusions/Significance A single molecule, PCA, produced in different quantities by the two phz gene clusters acted as the functional mediator and the two phz gene clusters developed a specific regulatory mechanism which acts through 5′-UTR to transfer a single, but complex bacterial signaling event in Pseudomonas sp. strain M18. PMID:21559370

Draft Genome Sequence of Pseudomonas sp. Strain LFM046, a Producer of Medium-Chain-Length Polyhydroxyalkanoate.

PubMed

Cardinali-Rezende, Juliana; Alexandrino, Paulo Moises Raduan; Nahat, Rafael Augusto Theodoro Pereira de Souza; Sant'Ana, Débora Parrine Vieira; Silva, Luiziana Ferreira; Gomez, José Gregório Cabrera; Taciro, Marilda Keico

2015-08-20

Pseudomonas sp. LFM046 is a medium-chain-length polyhydroxyalkanoate (PHAMCL) producer capable of using various carbon sources (carbohydrates, organic acids, and vegetable oils) and was first isolated from sugarcane cultivation soil in Brazil. The genome sequence was found to be 5.97 Mb long with a G+C content of 66%. Copyright © 2015 Cardinali-Rezende et al.

Draft Genome Sequence of Pseudomonas sp. EpS/L25, Isolated from the Medicinal Plant Echinacea purpurea and Able To Synthesize Antimicrobial Compounds.

PubMed

Presta, Luana; Bosi, Emanuele; Fondi, Marco; Maida, Isabel; Perrin, Elena; Miceli, Elisangela; Maggini, Valentina; Bogani, Patrizia; Firenzuoli, Fabio; Di Pilato, Vincenzo; Rossolini, Gian Maria; Mengoni, Alessio; Fani, Renato

2016-05-05

We announce here the draft genome sequence of Pseudomonas sp. strain EpS/L25, isolated from the stem/leaves of the medicinal plant Echinacea purpurea This genome will allow for comparative genomics in order to identify genes associated with the production of bioactive compounds and antibiotic resistance. Copyright © 2016 Presta et al.

Insight into the composition and degradation potential of dissolved organic matter with different hydrophobicity in landfill leachates.

PubMed

He, Xiao-Song; Xi, Bei-Dou; Gao, Ru-Tai; Zhang, Hui; Dang, Qiu-Ling; Li, Dan; Huang, Cai-Hong

2016-02-01

Dissolved organic matter (DOM) isolated from the leachates with different landfill ages was fractionated into hydrophobic acid (HOA), hydrophobic neutral (HON), hydrophobic base (HOB) fractions and hydrophilic matter (HIM) based on hydrophobicity, and the composition and degradation potential of the bulk DOM and its fractions were investigated by excitation-emission matrix fluorescence spectra coupled with parallel factor analysis. Results showed that the bulk DOM comprised fulvic-, humic-, tryptophan- and tyrosine-like substances, as well as component C1, whose composition and origin was unidentified. Landfill process increased the content of component C1, fulvic- and humic-like matter. The HON fractions comprised primarily component C1 and tyrosine-like matter. The HOA, HOB and HIM fractions isolated from the young leachates consisted mainly of tryptophan- and tyrosine-like substances. As to the intermediate and old leachates, the HOA and HOB fractions comprised mainly component C1, while the HIM comprised mainly fulvic-like matter. The HIM showed the most resistant against biodegradation among the four fractions, and was the main component of leachate treatment. Advanced oxidation and/or membrane treatment are recommended to remove the HIM fraction due to its hydrophilic and stable characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Environmental conditions affecting exopolysaccharide production by Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.

PubMed

Kiliç, Nur Koçberber; Dönmez, Gönül

2008-06-15

Three different chromium-resistant microorganisms (Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.) were tested with regard to their EPS production at different pH levels, temperatures, Cr(VI) concentrations, and incubation periods. The optimum pH level was 7 for P. aeruginosa and Micrococcus sp., while it was 8 for Ochrobactrum sp. according to the highest EPS amount at 100 mg/L Cr(VI) concentration. The highest production of EPSs by the three bacteria was obtained under different environmental conditions. P. aeruginosa produced the highest EPS (863.3 mg/L) after incubation for 96 h on media with 50 mg/L Cr(VI) at 20 degrees C, Micrococcus sp. gave the highest yield (444.6 mg/L) after incubation for 72 h on media with 100 mg/L Cr(VI) at the same temperature, and Ochrobactrum sp. had the highest production (430.5 mg/L) on media with 150 mg/L Cr(VI) at 30 degrees C at the end of 48 h of incubation.

Effects of the combination between bio-surfactant product types and washing times on the removal of crude oil in nonwoven fabric

NASA Astrophysics Data System (ADS)

Triawan, Agus; Ni'matuzahroh, Supriyanto, Agus

2017-06-01

This research aimed to characterize bio-surfactants produced by Bacillus subtilis 3KP, Pseudomonas putida T1-8, Micrococcus sp. L II 61 and Acinetobacter sp. P 2(1) and to investigate its combination's effects on the removal of crude oil in nonwoven fabric with different washing times vary from 12, 24 to 36 hours. The production of bio-surfactants was done on Synthetic Mineral Water mixed with molasses 4% within four days. The bio-surfactant products were characterized by measuring the Surface Tension (ST) (mN/m) and Emulsion Activity (EA) (%). Oil removal experiment was done by mixing 10 mL bio-surfactant with nonwoven fabric that contains crude oil into 50 mL bottle inside a shaker. The removed crude oil was extracted with n-hexane and measured gravimetrically. The results were then being analyzed with two ways ANOVA and Duncan test. Bio-surfactant produced by four bacteria has variations of Surface Tension and Emulsion Activity values. Bio-surfactant produced by Bacillus subtilis 3KP and Pseudomonas putida T1-8 showed the increasing of crude oil removal as washing times increase, while bio-surfactant produced by Micrococcus sp. L II 61 and Acinetobacter sp. P2(1) showed the decreasing result at 36 hours. However, the combination that showed the best result was Acinetobacter sp. P 2(1) at 24 hours valued 65,3%.

Cloning of genes involved in the biosynthesis of pseudobactin, a high-affinity iron transport agent of a plant growth-promoting Pseudomonas strain.

PubMed Central

Moores, J C; Magazin, M; Ditta, G S; Leong, J

1984-01-01

A gene bank of DNA from plant growth-promoting Pseudomonas sp. strain B10 was constructed using the broad host-range conjugative cosmid pLAFR1. The recombinant cosmids contained insert DNA averaging 21.5 kilobase pairs in length. Nonfluorescent mutants of Pseudomonas sp. strain B10 were obtained by mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine, ethyl methanesulfonate, or UV light and were defective in the biosynthesis of its yellow-green, fluorescent siderophore (microbial iron transport agent) pseudobactin. No yellow-green, fluorescent mutants defective in the production of pseudobactin were identified. Nonfluorescent mutants were individually complemented by mating the gene bank en masse and identifying fluorescent transconjugants. Eight recombinant cosmids were sufficient to complement 154 nonfluorescent mutants. The pattern of complementation suggests that a minimum of 12 genes arranged in four gene clusters is required for the biosynthesis of pseudobactin. This minimum number of genes seems reasonable considering the structural complexity of pseudobactin. Images PMID:6690426

Microbial dynamics in mixed culture biofilms of bacteria surviving sanitation of conveyor belts in salmon-processing plants.

PubMed

Langsrud, S; Moen, B; Møretrø, T; Løype, M; Heir, E

2016-02-01

The microbiota surviving sanitation of salmon-processing conveyor belts was identified and its growth dynamics further investigated in a model mimicking processing surfaces in such plants. A diverse microbiota dominated by Gram-negative bacteria was isolated after regular sanitation in three salmon processing plants. A cocktail of 14 bacterial isolates representing all genera isolated from conveyor belts (Listeria, Pseudomonas, Stenotrophomonas, Brochothrix, Serratia, Acinetobacter, Rhodococcus and Chryseobacterium) formed stable biofilms on steel coupons (12°C, salmon broth) of about 10(9) CFU cm(-2) after 2 days. High-throughput sequencing showed that Listeria monocytogenes represented 0·1-0·01% of the biofilm population and that Pseudomonas spp dominated. Interestingly, both Brochothrix sp. and a Pseudomonas sp. dominated in the surrounding suspension. The microbiota surviving sanitation is dominated by Pseudomonas spp. The background microbiota in biofilms inhibit, but do not eliminate L. monocytogenes. The results highlights that sanitation procedures have to been improved in the salmon-processing industry, as high numbers of a diverse microbiota survived practical sanitation. High-throughput sequencing enables strain level studies of population dynamics in biofilm. © 2015 The Society for Applied Microbiology.

Substance P delays apoptosis, enhancing keratitis after Pseudomonas aeruginosa infection.

PubMed

Zhou, Zimei; Barrett, Ronald P; McClellan, Sharon A; Zhang, Yunfan; Szliter, Elizabeth A; van Rooijen, Nico; Hazlett, Linda D

2008-10-01

Apoptosis was examined after Pseudomonas aeruginosa corneal infection in C57BL/6 (B6, susceptible) and BALB/c (resistant) mice. TUNEL staining, real-time RT-PCR, polymorphonuclear neutrophils (PMNs) and macrophage (Mphi) depletion, and immunostaining were used. Intense TUNEL staining was seen in BALB/c versus B6 cornea at 1 versus 3 days after infection (PI) and correlated with mRNA levels for caspase-3. TUNEL staining (with or without PMN depletion) and PMN immunostaining revealed the PMN as the major apoptotic cell for both groups. Next, B6 mice with high corneal levels of the antiapoptosis neuropeptide, substance P (SP), were treated with the SP antagonist, Spantide I (with/without Mphi depletion), resulting in earlier apoptosis and diminished disease only when M(phi)s were present. SP interactions with M(phi)s were explored further by eliciting cells from both groups and stimulating them with lipopolysaccharide (LPS), with or without SP. LPS with SP treatment decreased the number of apoptotic M(phi)s in B6 but not BALB/c mice and correlated with reduced mRNA expression of NK-1R (major SP receptor) on BALB/c cells. In addition, mRNA expression for IL-12 was upregulated in LPS-stimulated B6 M(phi)s, although cells from BALB/c mice expressed more IL-10. These studies provide evidence that PMN apoptosis is delayed in the cornea of B6 versus BALB/c mice after bacterial infection; that in B6 mice, blocking SP interaction with the NK-1R promotes earlier apoptosis and improves disease outcome; that M(phi)s regulate PMN apoptosis; and that M(phi)s from B6 versus BALB/c mice differ in expression of the NK-1R and cytokines produced after LPS challenge.

Biodegradation of indole at high concentration by persolvent fermentation with Pseudomonas sp. ST-200.

PubMed

Doukyu, N; Aono, R

1997-05-01

Pseudomonas sp. strain ST-200 grew on indole as a sole carbon source. The minimal inhibitory concentration of indole was 0.3 mg/ml for ST-200. However, ST-200 grew in a persolvent fermentation system containing a large amount of indole (a medium containing 20% by vol. diphenylmethane and 4 mg/ml indole), because most of the indole was partitioned in the organic solvent layer. When the organism was grown in the medium containing indole at 1 mg/ml in the presence of diphenylmethane, more than 98% of the indole was consumed after 48h. Isatic acid (0.4 mg/ml) and isatin (0.03 mg/ml) were produced as the metabolites in the aqueous medium layer.

Saturation mutagenesis in selected amino acids to shift Pseudomonas sp. acidic lipase Lip I.3 substrate specificity and activity.

PubMed

Panizza, Paola; Cesarini, Silvia; Diaz, Pilar; Rodríguez Giordano, Sonia

2015-01-25

Several Pseudomonas sp. CR611 Lip I.3 mutants with overall increased activity and a shift towards longer chain substrates were constructed. Substitution of residues Y29 and W310 by smaller amino acids provided increased activity on C18-substrates. Residues G152 and S154, modified to study their influence on interfacial activation, displayed a five and eleven fold increased activity.

The bacterial degradation of flavonoids. Oxidative fission of the A-ring of dihydrogossypetin by a Pseudomonas sp

PubMed Central

Jeffrey, A. M.; Jerina, D. M.; Self, R.; Evans, W. C.

1972-01-01

Cell-free extracts prepared from a Pseudomonas sp., grown on (+)-catechin, oxidized dihydrogossypetin (3′,4′,5,7,8-pentahydroxyflavanonol) by cleaving the A-ring to form oxaloacetic acid from C-5, C-6, C-7 and C-8 together with 5-(3,4-dihydroxyphenyl)-4-hydroxy-3-oxovalero-δ-lactone. The structure of this lactone was confirmed by synthesis of related phenylvalerolactones. PMID:4198081

Hypersensitivity pneumonitis in a beautician.

PubMed

Soumagne, Thibaud; Reboux, Gabriel; Degano, Bruno; Dalphin, Jean Charles

2016-11-01

A 52-year-old non-smoking beautician using a skincare device spraying steam and ozone (a "vapozone" facial steamer) was referred for progressive dyspnea and dry cough during working periods. Although spirometry was normal, she had decreased diffusing capacity of the lung for carbon monoxide, bronchiolitis with air trapping on high-resolution CT scan and 60% lymphocytosis by bronchoalveolar lavage. Twenty-six antigens were tested and serum-specific precipitins were found mainly against Pseudomonas sp. and Mycobacterium mucogenicum. Cultures from her skincare device isolated Pseudomonas sp. Outcome was favorable with cessation of occupational exposure to the device, without any medication. This is the first report of a case of HP in a beautician due to steam contaminated by Pseudomonas sp. from a vapozone. HP, and not only asthma and contact dermatitis, should be suspected in beauticians with respiratory symptoms. Am. J. Ind. Med. 59:1041-1045, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Natural Electrotransformation of Lightning-Competent Pseudomonas sp. Strain N3 in Artificial Soil Microcosms

PubMed Central

Cérémonie, Hélène; Buret, François; Simonet, Pascal; Vogel, Timothy M.

2006-01-01

The lightning-competent Pseudomonas sp. strain N3, recently isolated from soil, has been used to study the extent of natural electrotransformation (NET) or lightning transformation as a horizontal gene transfer mechanism in soil. The variation of electrical fields applied to the soil with a laboratory-scale lightning system provides an estimate of the volume of soil affected by NET. Based on the range of the electric field that induces NET of Pseudomonas strain N3, the volume of soil, where NET could occur, ranges from 2 to 950 m3 per lightning strike. The influence of DNA parameters (amount, size, and purity) and DNA soil residence time were also investigated. NET frequencies (electrotransformants/recipient cells) ranged from 10−8 for cell lysate after 1 day of residence in soil to 4 × 10−7 with a purified plasmid added immediately before the lightning. The electrical field gradient (in kilovolts per cm) also played a role as NET frequencies ranging from 1 × 10−5 at 2.3 kV/cm to 1.7 × 10−4 at 6.5 kV/cm. PMID:16597934

In vitro synthesis of polyhydroxyalkanoate (PHA) incorporating lactate (LA) with a block sequence by using a newly engineered thermostable PHA synthase from Pseudomonas sp. SG4502 with acquired LA-polymerizing activity.

PubMed

Tajima, Kenji; Han, Xuerong; Satoh, Yasuharu; Ishii, Ayako; Araki, Yuji; Munekata, Masanobu; Taguchi, Seiichi

2012-04-01

Recently, we succeeded in isolating a thermotolerant bacterium, Pseudomonas sp. SG4502, which is capable of accumulating polyhydroxyalkanoate (PHA) even at 55 °C, as a source of thermostable enzymes. In this study, we cloned a pha locus from the bacterium and identified two genes encoding PHA synthases (PhaC1(SG) and PhaC2(SG)). Two mutations, Ser324Thr and Gln480Lys, corresponding to those of a lactate (LA)-polymerizing enzyme (LPE) from mesophilic Pseudomonas sp. 61-3 were introduced into PhaC1(SG) to evaluate the potential of the resulting protein as a "thermostable LPE". The mutated PhaC1(SG) [PhaC1(SG)(STQK)] showed high thermal stability in synthesizing P(LA-co-3HB) in an in vitro reaction system under a range of high temperatures. Requirement of 3HBCoA as a priming unit for LA polymerization by the LPE has been suggested in both of the in vitro and in vivo experiments. Based on the finding, the PhaC1(SG)(STQK)-mediated synthesis of a LA-based copolymer with a block sequence was achieved in the in vitro system by sequential feeding of the corresponding two substrates. This in vitro reaction system using the thermostable LPE provides us with a versatile way to synthesize the various types of LA-based copolymers with desired sequence patterns, random or block, depending on the way of supplying hydroxyalkanoates (mixed or sequential feeding).

Synthesis and antimicrobial activity of new 1-[(tetrazol-5-yl)methyl] indole derivatives, their 1,2,4-triazole thioglycosides and acyclic analogs.

PubMed

El-Sayed, Weal A; Abdel Megeid, Randa E; Abbas, Hebat-Allah S

2011-07-01

New 1-[(tetrazol-5-yl)methyl]indole derivatives, their acyclic nucleoside analogs and the corresponding glycoside derivatives were synthesized. Furthermore, the [)(1,2,4-triazol-3-yl)methyl])-2H-tetrazole derivative as well as the corresponding thioglucoside were prepared. The synthesized compounds were tested for their antimicrobial activity against Aspergillus Niger, Penicillium sp, Candida albican, Bacillus subtilis, Streptococcus lacti, Escherichia coli, Pseudomonas sp., and streptomyces sp. Compounds 3, 5 and 19b exhibited potent antibacterial activity and compounds 4, 5 and 10 exhibited high activities against the tested fungi compared with fusidic acid.

Phenotypic and genotypic characterization of phenanthrene-degrading fluorescent Pseudomonas biovars.

PubMed Central

Johnsen, K; Andersen, S; Jacobsen, C S

1996-01-01

A total of 41 phenanthrene degraders were isolated from a former coal gasification site by using Pseudomonas-selective Gould's S1 medium. All isolates were found to belong to the fluorescent Pseudomonas group and were subjected to characterization by phenotypic methods, including classical taxonomic tests, API 20NE, and Biolog GN, and the strains were further characterized by the genotypic method repetitive extragenic palindromic PCR (REP-PCR). By using classical tests, the population was found to consist of 38 strains belonging to P. fluorescens, 2 P. putida strains, and 1 Pseudomonas sp. Bacteria in phenograms from Biolog GN and REP-PCR data were divided into groups, which were in good agreement with classical test and API 20NE results. We found a nonfluorescent group of 22 bacteria inconsistent with any Pseudomonas sp. in Bergey's Manual of Systematic Bacteriology. The group showed small differences in the genotypic test, indicating that all 22 isolates were not recent clones of the same isolate. Analyses of the nonfluorescent group indicated that it belonged to Pseudomonas, but the group could not be affiliated with P. fluorescens because of differences in DNA-DNA hybridization. Identifications using classical tests and API 20NE were found to correlate, but Biolog GN identifications after 24-h incubation resulted very often in the distantly related P. corrugata. The reproducibilities of individual tests of each phenotypic method were assessed, and low reproducibilities were mainly found to be associated with specific Biolog GN test wells. Classical tests and API 20NE proved to be the best for identification of isolates, whereas Biolog GN and REP-PCR were found to be the best tests for high resolution among these closely related isolates. PMID:8837438

Complete genome of Pseudomonas sp. strain L10.10, a psychrotolerant biofertilizer that could promote plant growth.

PubMed

See-Too, Wah Seng; Lim, Yan-Lue; Ee, Robson; Convey, Peter; Pearce, David A; Yin, Wai-Fong; Chan, Kok Gan

2016-03-20

Pseudomonas sp. strain L10.10 (=DSM 101070) is a psychrotolerant bacterium which was isolated from Lagoon Island, Antarctica. Analysis of its complete genome sequence indicates its possible role as a plant-growth promoting bacterium, including nitrogen-fixing ability and indole acetic acid (IAA)-producing trait, with additional suggestion of plant disease prevention attributes via hydrogen cyanide production. Copyright © 2016 Elsevier B.V. All rights reserved.

Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

PubMed

Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

2015-07-06

Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.

Use of Silica-Encapsulated Pseudomonas sp. Strain NCIB 9816-4 in Biodegradation of Novel Hydrocarbon Ring Structures Found in Hydraulic Fracturing Waters

PubMed Central

Aukema, Kelly G.; Kasinkas, Lisa; Aksan, Alptekin

2014-01-01

The most problematic hydrocarbons in hydraulic fracturing (fracking) wastewaters consist of fused, isolated, bridged, and spiro ring systems, and ring systems have been poorly studied with respect to biodegradation, prompting the testing here of six major ring structural subclasses using a well-characterized bacterium and a silica encapsulation system previously shown to enhance biodegradation. The direct biological oxygenation of spiro ring compounds was demonstrated here. These and other hydrocarbon ring compounds have previously been shown to be present in flow-back waters and waters produced from hydraulic fracturing operations. Pseudomonas sp. strain NCIB 9816-4, containing naphthalene dioxygenase, was selected for its broad substrate specificity, and it was demonstrated here to oxidize fundamental ring structures that are common in shale-derived waters but not previously investigated with this or related enzymes. Pseudomonas sp. NCIB 9816-4 was tested here in the presence of a silica encasement, a protocol that has previously been shown to protect bacteria against the extremes of salinity present in fracking wastewaters. These studies demonstrate the degradation of highly hydrophobic compounds by a silica-encapsulated model bacterium, demonstrate what it may not degrade, and contribute to knowledge of the full range of hydrocarbon ring compounds that can be oxidized using Pseudomonas sp. NCIB 9816-4. PMID:24907321

Pseudomonas abyssi sp. nov., isolated from the abyssopelagic water of the Mariana Trench.

PubMed

Wei, Yuli; Mao, Haiyan; Xu, Yunping; Zou, Wencai; Fang, Jiasong; Blom, Jochen

2018-06-21

A novel heterotrophic, Gram-stain-negative, aerobic, rod-shaped bacterium, designated as strain MT5 T , was isolated from deep seawater in the Mariana Trench and characterized phylogenetically and phenotypically. Bacterial optimal growth occurred at 28 °C (range, 4-45 °C), pH 5-7 (pH 4-11) and with 3-7 % (w/v) NaCl (0-18 %). Phylogenetic analysis based on 16S rRNA gene sequence showed that strain MT5 T was related to members of the genus Pseudomonas and shared the highest sequence identities with Pseudomonas pachastrellae CCUG 46540 T (99.6 %), Pseudomonas aestusnigri VGXO14 T (98.5 %) and Pseudomonas oceani KX 20 T (98.4 %). The 16S rRNA gene sequence identities between strain MT5 T and other members of the genus Pseudomonas were below 96.7 %. The digital DNA-DNA hybridization values between strain MT5 T and the two type strains, P. pachastrellae and P. aestusnigri, were 38.9±2.5 and 25.8±2.4 %, respectively. The average nucleotide identity values between strain MT5 T and the two type strains were 90.3 and 87.0 %, respectively. Strain MT5 T and the two type strains shared 94.98 and 86.2 % average amino acid identity, and 30 and 33 Karlin genomic signature, respectively. The sole respiratory menaquinone was Q-9. The major polar lipids were phosphatidylethanolamine, diphosphatidyglycerol and phosphatidylglycerol. The predominant cellular fatty acids of strain MT5 T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) (35.3 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (24.1 %), C16 : 0 (15.9 %) and C12 : 0 (7.2 %). The G+C content of the genomic DNA was 61.2 mol%. The combined genotypic and phenotypic data indicated that strain MT5 T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas abyssi sp. nov. is proposed, with the type strain MT5 T (=KCTC 62295 T =MCCC 1K03351 T ).

Characterization of Two Novel Propachlor Degradation Pathways in Two Species of Soil Bacteria

PubMed Central

Martin, Margarita; Mengs, Gerardo; Allende, Jose Luis; Fernandez, Javier; Alonso, Ramon; Ferrer, Estrella

1999-01-01

Propachlor (2-chloro-N-isopropylacetanilide) is an acetamide herbicide used in preemergence. In this study, we isolated and characterized a soil bacterium, Acinetobacter strain BEM2, that was able to utilize this herbicide as the sole and limiting carbon source. Identification of the intermediates of propachlor degradation by this strain and characterization of new metabolites in the degradation of propachlor by a previously reported strain of Pseudomonas (PEM1) support two different propachlor degradation pathways. Washed-cell suspensions of strain PEM1 with propachlor accumulated N-isopropylacetanilide, acetanilide, acetamide, and catechol. Pseudomonas strain PEM1 grew on propachlor with a generation time of 3.4 h and a Ks of 0.17 ± 0.04 mM. Acinetobacter strain BEM2 grew on propachlor with a generation time of 3.1 h and a Ks of 0.3 ± 0.07 mM. Incubations with strain BEM2 resulted in accumulation of N-isopropylacetanilide, N-isopropylaniline, isopropylamine, and catechol. Both degradative pathways were inducible, and the principal product of the carbon atoms in the propachlor ring was carbon dioxide. These results and biodegradation experiments with the identified metabolites indicate that metabolism of propachlor by Pseudomonas sp. strain PEM1 proceeds through a different pathway from metabolism by Acinetobacter sp. strain BEM2. PMID:9925619

40 CFR 503.8 - Sampling and analysis.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-00000-1). (5) Salmonella sp. bacteria. Part 9260 D., “Standard Methods for the Examination of Water and... 20005; or Kenner, B.A. and H.P. Clark, “Detection and enumeration of Salmonella and Pseudomonas...

40 CFR 503.8 - Sampling and analysis.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-00000-1). (5) Salmonella sp. bacteria. Part 9260 D., “Standard Methods for the Examination of Water and... 20005; or Kenner, B.A. and H.P. Clark, “Detection and enumeration of Salmonella and Pseudomonas...

Biosynthesis, Chemical Structure, and Structure-Activity Relationship of Orfamide Lipopeptides Produced by Pseudomonas protegens and Related Species

PubMed Central

Ma, Zongwang; Geudens, Niels; Kieu, Nam P.; Sinnaeve, Davy; Ongena, Marc; Martins, José C.; Höfte, Monica

2016-01-01

Orfamide-type cyclic lipopeptides (CLPs) are biosurfactants produced by Pseudomonas and involved in lysis of oomycete zoospores, biocontrol of Rhizoctonia and insecticidal activity against aphids. In this study, we compared the biosynthesis, structural diversity, in vitro and in planta activities of orfamides produced by rhizosphere-derived Pseudomonas protegens and related Pseudomonas species. Genetic characterization together with chemical identification revealed that the main orfamide compound produced by the P. protegens group is orfamide A, while the related strains Pseudomonas sp. CMR5c and CMR12a produce orfamide B. Comparison of orfamide fingerprints led to the discovery of two new orfamide homologs (orfamide F and orfamide G) in Pseudomonas sp. CMR5c. The structures of these two CLPs were determined by nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis. Mutagenesis and complementation showed that orfamides determine the swarming motility of parental Pseudomonas sp. strain CMR5c and their production was regulated by luxR type regulators. Orfamide A and orfamide B differ only in the identity of a single amino acid, while orfamide B and orfamide G share the same amino acid sequence but differ in length of the fatty acid part. The biological activities of orfamide A, orfamide B, and orfamide G were compared in further bioassays. The three compounds were equally active against Magnaporthe oryzae on rice, against Rhizoctonia solani AG 4-HGI in in vitro assays, and caused zoospore lysis of Phytophthora and Pythium. Furthermore, we could show that orfamides decrease blast severity in rice plants by blocking appressorium formation in M. oryzae. Taken all together, our study shows that orfamides produced by P. protegens and related species have potential in biological control of a broad spectrum of fungal plant pathogens. PMID:27065956

Anaerobic biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons by a facultative anaerobe Pseudomonas sp. JP1.

PubMed

Liang, Lei; Song, Xiaohui; Kong, Jing; Shen, Chenghui; Huang, Tongwang; Hu, Zhong

2014-11-01

Polycyclic aromatic hydrocarbons (PAHs) are harmful persistent organic pollutants, while the high-molecular-weight (HMW) PAHs are even more detrimental to the environment and human health. However, microbial anaerobic degradation of HMW PAHs has rarely been reported. One facultative anaerobe Pseudomonas sp. JP1 was isolated from Shantou Bay, Shantou, China, which could degrade a variety of HMW PAHs. After 40 days cultivation with strain JP1, anaerobic biodegradation rate of benzo[a]pyrene (BaP), fluoranthene, and phenanthrene was 30, 47, and 5 %, respectively. Consumption of nitrate as the electron acceptor was confirmed by N-(1-naphthyl) ethylenediamine spectrophotometry. Supplementation of sodium sulfite, maltose, or glycine, and in a salinity of 0-20 ‰ significantly stimulated anaerobic degradation of BaP. Lastly, the anaerobic degradation metabolites of BaP by strain JP1 were investigated using GC/MS, and the degradation pathway was proposed. This study is helpful for further studies on the mechanism of anaerobic biodegradation of PAHs.

Various effects of fluorescent bacteria of the genus Pseudomonas containing ACC deaminase on wheat seedling growth.

PubMed

Magnucka, Elżbieta G; Pietr, Stanisław J

2015-12-01

The study evaluates the effect of rhizobacteria having 1-aminocyclopropane-1-carboxylate deaminase (ACCd) on the development of wheat seedlings. This enzyme has been proposed to play a key role in microbe-plant association. Three fluorescent pseudomonads containing this deaminase were selected from 70 strains of pseudomonads isolated from rhizosphere of wheat (Triticum aestivum L.) and rape (Brassica napus L.). These bacteria, varied significantly in the ability to both biosynthesize auxins and hydrolyze ACC. Among them, Pseudomonas brassicacearum subsp. brassicacearum strain RZ310 presented the highest activities of ACC deaminase during 96h of growth in liquid Dworkin and Foster (DF) salt medium. Additionally, this rape rhizosphere strain did not produce indoles. Two other isolates, Pseudomonas sp. PO283 and Pseudomonas sp. PO366, secreted auxins only in the presence of their precursor. Phylogenetic analysis of the 16S rRNA gene and four other protein-encoding genes indicated that these wheat rhizosphere isolates belonged to the fluorescent Pseudomonas group. Moreover, the effects of these strains on wheat seedling growth under in vitro conditions were markedly dependent on both their cell suspensions used to grain inoculation and nutrient conditions. Strains tested had beneficial influence on wheat seedlings mainly at low cell densities. In addition, access to nutrients markedly changed bacteria action on cereal growth. Their presence generally favored the positive effects of pseudomonads on length and the estimated biomasses of wheat coleoptiles. Despite these general rules, impacts of each isolate on the growth parameters of cereal seedlings were unique. Copyright © 2015 Elsevier GmbH. All rights reserved.

Enhancement of biodegradation of crude petroleum-oil in contaminated water by the addition of nitrogen sources.

PubMed

Mukred, A M; Hamid, A A; Hamzah, A; Yusoff, W M Wan

2008-09-01

Addition of nitrogen sources as supplementary nutrient into MSM medium to enhance biodegradation by stimulating the growth four isolates, Acinetobacter faecalis, Staphylococcus sp., Pseudomonas putida and Neisseria elongata isolated from petroleum contaminated groundwater, wastewater aeration pond and biopond at the oil refinery Terengganu Malaysia was investigated. The organic nitrogen sources tested not only supported growth but also enhances biodegradation of 1% Tapis crude oil. All four isolates showed good growth especially when peptone was employed as the organic nitrogen compared to growth in the basal medium. Gas chromatography showed that more then 91, 93, 94 and 95% degradation of total hydrocarbon was observed after 5 days of incubation by isolates Pseudomonas putida, Neisseria elongate, Acinetobacter faecalis and Staphylococcus sp., respectively.

Screening for and isolation and identification of malathion-degrading bacteria: cloning and sequencing a gene that potentially encodes the malathion-degrading enzyme, carboxylestrase in soil bacteria.

PubMed

Goda, Sayed K; Elsayed, Iman E; Khodair, Taha A; El-Sayed, Walaa; Mohamed, Mervat E

2010-11-01

Five malathion-degrading bacterial strains were enriched and isolated from soil samples collected from different agricultural sites in Cairo, Egypt. Malathion was used as a sole source of carbon (50 mg/l) to enumerate malathion degraders, which were designated as IS1, IS2, IS3, IS4, and IS5. They were identified, based on their morphological and biochemical characteristics, as Pseudomonas sp., Pseudomonas putida, Micrococcus lylae, Pseudomonas aureofaciens, and Acetobacter liquefaciens, respectively. IS1 and IS2, which showed the highest degrading activity, were selected for further identification by partial sequence analysis of their 16S rRNA genes. The 16S rRNA gene of IS1 shared 99% similarity with that of Alphaprotoebacterium BAL284, while IS2 scored 100% similarity with that of Pseudomonas putida 32zhy. Malathion residues almost completely disappeared within 6 days of incubation in IS2 liquid cultures. LC/ESI-MS analysis confirmed the degradation of malathion to malathion monocarboxylic and dicarboxylic acids, which formed as a result of carboxylesterase activity. A carboxylesterase gene (CE) was amplified from the IS2 genome by using specifically designed PCR primers. The sequence analysis showed a significant similarity to a known CE gene in different Pseudomonas sp. We report here the isolation of a new malathion-degrading bacteria from soils in Egypt that may be very well adapted to the climatic and environmental conditions of the country. We also report the partial cloning of a new CE gene. Due to their high biodegradation activity, the bacteria isolated from this work merit further study as potential biological agents for the remediation of soil, water, or crops contaminated with the pesticide malathion.

Pesticide tolerant and phosphorus solubilizing Pseudomonas sp. strain SGRAJ09 isolated from pesticides treated Achillea clavennae rhizosphere soil.

PubMed

Rajasankar, R; Manju Gayathry, G; Sathiavelu, A; Ramalingam, C; Saravanan, V S

2013-05-01

In this study, an attempt was made to identify an effective phosphate solubilizing bacteria from pesticide polluted field soil. Based on the formation of solubilization halo on Pikovskaya's agar, six isolates were selected and screened for pesticide tolerance and phosphate (P) solubilization ability through liquid assay. The results showed that only one strain (SGRAJ09) obtained from Achillea clavennae was found to tolerate maximum level of the pesticides tested and it was phylogenetically identified as Pseudomonas sp. It possessed a wide range of pesticide tolerance, ranging from 117 μg mL(-1) for alphamethrin to 2,600 μg mL(-1) for endosulfan. The available P concentrations increased with the maximum and double the maximum dose of monocrotophos and imidacloprid, respectively. On subjected to FT-IR and HPLC analysis, the presence of organic acids functional group in the culture broth and the production of gluconic acid as dominant acid aiding the P solubilization were identified. On comparison with control broth, monocrotophos and imidacloprid added culture broth showed quantitatively high organic acids production. In addition to gluconic acid production, citric and acetic acids were also observed in the pesticide amended broth. Furthermore, the Pseudomonas sp. strain SGRAJ09 possessed all the plant growth promoting traits tested. In presence of monocrotophos and imidacloprid, its plant growth promoting activities were lower than that of the pesticides unamended treatment.

Pseudomonas caspiana sp. nov., a citrus pathogen in the Pseudomonas syringae phylogenetic group.

PubMed

Busquets, Antonio; Gomila, Margarita; Beiki, Farid; Mulet, Magdalena; Rahimian, Heshmat; García-Valdés, Elena; Lalucat, Jorge

2017-07-01

In a screening by multilocus sequence analysis of Pseudomonas strains isolated from diverse origins, 4 phylogenetically closely related strains (FBF58, FBF102 T , FBF103, and FBF122) formed a well-defined cluster in the Pseudomonas syringae phylogenetic group. The strains were isolated from citrus orchards in northern Iran with disease symptoms in the leaves and stems and its pathogenicity against citrus plants was demonstrated. The whole genome of the type strain of the proposed new species (FBF102 T =CECT 9164 T =CCUG 69273 T ) was sequenced and characterized. Comparative genomics with the 14 known Pseudomonas species type strains of the P. syringae phylogenetic group demonstrated that this strain belonged to a new genomic species, different from the species described thus far. Genome analysis detected genes predicted to be involved in pathogenesis, such as an atypical type 3 secretion system and two type 6 secretion systems, together with effectors and virulence factors. A polyphasic taxonomic characterization demonstrated that the 4 plant pathogenic strains represented a new species, for which the name Pseudomonas caspiana sp. nov. is proposed. Copyright © 2017 Elsevier GmbH. All rights reserved.

Extracellular overproduction and preliminary crystallographic analysis of a family I.3 lipase

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

Angkawidjaja, Clement; You, Dong-Ju; Matsumura, Hiroyoshi

2007-03-01

A family I.3 lipase from Pseudomonas sp. MIS38 was secreted from Escherichia coli cells to the external medium, purified and crystallized and preliminary crystallographic studies were performed. A family I.3 lipase from Pseudomonas sp. MIS38 was secreted from Escherichia coli cells to the external medium, purified and crystallized and preliminary crystallographic studies were performed. The crystal was grown at 277 K by the hanging-drop vapour-diffusion method. Native X-ray diffraction data were collected to 1.7 Å resolution using synchrotron radiation at station BL38B1, SPring-8. The crystal belongs to space group P2{sub 1}, with unit-cell parameters a = 48.79, b = 84.06,more » c = 87.04 Å. Assuming the presence of one molecule per asymmetric unit, the Matthews coefficient V{sub M} was calculated to be 2.73 Å{sup 3} Da{sup −1} and the solvent content was 55%.« less

Pseudomonas aestusnigri sp. nov., isolated from crude oil-contaminated intertidal sand samples after the Prestige oil spill.

PubMed

Sánchez, David; Mulet, Magdalena; Rodríguez, Ana C; David, Zoyla; Lalucat, Jorge; García-Valdés, Elena

2014-03-01

Strains VGXO14(T) and Vi1 were isolated from the Atlantic intertidal shore from Galicia, Spain, after the Prestige oil spill. Both strains were Gram-negative rod-shaped bacteria with one polar inserted flagellum, strictly aerobic, and able to grow at 18-37°C, pH 6-10 and 2-10% NaCl. A preliminary analysis of the 16S rRNA and the partial rpoD gene sequences indicated that these strains belonged to the Pseudomonas genus but were distinct from any known Pseudomonas species. A polyphasic taxonomic approach including phylogenetic, chemotaxonomic, phenotypic and genotypic data confirmed that the strains belonged to the Pseudomonas pertucinogena group. In a multilocus sequence analysis, the similarity of VGXO14(T) and Vi1 to the closest type strain of the group, Pseudomonas pachastrellae, was 90.4%, which was lower than the threshold of 97% established to discriminate species in the Pseudomonas genus. The DNA-DNA hybridisation similarity between strains VGXO14(T) and Vi1 was 79.6%, but below 70% with the type strains in the P. pertucinogena group. Therefore, the strains should be classified within the genus Pseudomonas as a novel species, for which the name Pseudomonas aestusnigri is proposed. The type strain is VGXO14(T) (=CCUG 64165(T)=CECT 8317(T)). Copyright © 2013 Elsevier GmbH. All rights reserved.

Sustainable production of valuable compound 3-succinoyl-pyridine by genetically engineering Pseudomonas putida using the tobacco waste.

PubMed

Wang, Weiwei; Xu, Ping; Tang, Hongzhi

2015-11-17

Treatment of solid and liquid tobacco wastes with high nicotine content remains a longstanding challenge. Here, we explored an environmentally friendly approach to replace tobacco waste disposal with resource recovery by genetically engineering Pseudomonas putida. The biosynthesis of 3-succinoyl-pyridine (SP), a precursor in the production of hypotensive agents, from the tobacco waste was developed using whole cells of the engineered Pseudomonas strain, S16dspm. Under optimal conditions in fed-batch biotransformation, the final concentrations of product SP reached 9.8 g/L and 8.9 g/L from aqueous nicotine solution and crude suspension of the tobacco waste, respectively. In addition, the crystal compound SP produced from aqueous nicotine of the tobacco waste in batch biotransformation was of high purity and its isolation yield on nicotine was 54.2%. This study shows a promising route for processing environmental wastes as raw materials in order to produce valuable compounds.

Biosurfactant produced by novel Pseudomonas sp. WJ6 with biodegradation of n-alkanes and polycyclic aromatic hydrocarbons.

PubMed

Xia, Wenjie; Du, Zhifeng; Cui, Qingfeng; Dong, Hao; Wang, Fuyi; He, Panqing; Tang, YongChun

2014-07-15

Alkanes and polycyclic aromatic hydrocarbons (PAHs) have threatened the environment due to toxicity and poor bioavailability. Interest in degradation of these hazardous materials by biosurfactant-producing bacteria has been steadily increasing in recent years. In this work, a novel biosurfactant-producing Pseudomonas sp. WJ6 was isolated to degrade a wide range of n-alkanes and polycyclic aromatic hydrocarbons. Production of lipopeptide biosurfactant was observed in all biodegradable studies. These lipopeptides were purified and identified by C18 RP-HPLC system and electrospray ionization-mass spectrometry. Results of structural analysis showed that these lipopeptides generated from different hydrocarbons were classified to be surfactin, fengycin and lichenysin. Heavy-oil sludge washing experiments demonstrated that lipopeptides produced by Pseudomonas sp. WJ6 have 92.46% of heavy-oil washing efficiency. The obtained results indicate that this novel bacterial strain and its lipopeptides have great potentials in the environmental remediation and petroleum recovery. Copyright © 2014 Elsevier B.V. All rights reserved.

Dual-Bioaugmentation Strategy To Enhance Remediation of Cocontaminated Soil

PubMed Central

Roane, T. M.; Josephson, K. L.; Pepper, I. L.

2001-01-01

Although metals are thought to inhibit the ability of microorganisms to degrade organic pollutants, several microbial mechanisms of resistance to metal are known to exist. This study examined the potential of cadmium-resistant microorganisms to reduce soluble cadmium levels to enhance degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) under conditions of cocontamination. Four cadmium-resistant soil microorganisms were examined in this study. Resistant up to a cadmium concentration of 275 μg ml−1, these isolates represented the common soil genera Arthrobacter, Bacillus, and Pseudomonas. Isolates Pseudomonas sp. strain H1 and Bacillus sp. strain H9 had a plasmid-dependent intracellular mechanism of cadmium detoxification, reducing soluble cadmium levels by 36%. Isolates Arthrobacter strain D9 and Pseudomonas strain I1a both produced an extracellular polymer layer that bound and reduced soluble cadmium levels by 22 and 11%, respectively. Although none of the cadmium-resistant isolates could degrade 2,4-D, results of dual-bioaugmentation studies conducted with both pure culture and laboratory soil microcosms showed that each of four cadmium-resistant isolates supported the degradation of 500-μg ml−1 2,4-D by the cadmium-sensitive 2,4-D degrader Ralstonia eutropha JMP134. Degradation occurred in the presence of up to 24 μg of cadmium ml−1 in pure culture and up to 60 μg of cadmium g−1 in amended soil microcosms. In a pilot field study conducted with 5-gallon soil bioreactors, the dual-bioaugmentation strategy was again evaluated. Here, the cadmium-resistant isolate Pseudomonas strain H1 enhanced degradation of 2,4-D in reactors inoculated with R. eutropha JMP134 in the presence of 60 μg of cadmium g−1. Overall, dual bioaugmentation appears to be a viable approach in the remediation of cocontaminated soils. PMID:11425743

Biocontrol of the Potato Blackleg and Soft Rot Diseases Caused by Dickeya dianthicola.

PubMed

Raoul des Essarts, Yannick; Cigna, Jérémy; Quêtu-Laurent, Angélique; Caron, Aline; Munier, Euphrasie; Beury-Cirou, Amélie; Hélias, Valérie; Faure, Denis

2016-01-01

Development of protection tools targeting Dickeya species is an important issue in the potato production. Here, we present the identification and the characterization of novel biocontrol agents. Successive screenings of 10,000 bacterial isolates led us to retain 58 strains that exhibited growth inhibition properties against several Dickeya sp. and/or Pectobacterium sp. pathogens. Most of them belonged to the Pseudomonas and Bacillus genera. In vitro assays revealed a fitness decrease of the tested Dickeya sp. and Pectobacterium sp. pathogens in the presence of the biocontrol agents. In addition, four independent greenhouse assays performed to evaluate the biocontrol bacteria effect on potato plants artificially contaminated with Dickeya dianthicola revealed that a mix of three biocontrol agents, namely, Pseudomonas putida PA14H7 and Pseudomonas fluorescens PA3G8 and PA4C2, repeatedly decreased the severity of blackleg symptoms as well as the transmission of D. dianthicola to the tuber progeny. This work highlights the use of a combination of biocontrol strains as a potential strategy to limit the soft rot and blackleg diseases caused by D. dianthicola on potato plants and tubers. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Biocontrol of the Potato Blackleg and Soft Rot Diseases Caused by Dickeya dianthicola

PubMed Central

Raoul des Essarts, Yannick; Cigna, Jérémy; Quêtu-Laurent, Angélique; Caron, Aline; Munier, Euphrasie; Beury-Cirou, Amélie

2015-01-01

Development of protection tools targeting Dickeya species is an important issue in the potato production. Here, we present the identification and the characterization of novel biocontrol agents. Successive screenings of 10,000 bacterial isolates led us to retain 58 strains that exhibited growth inhibition properties against several Dickeya sp. and/or Pectobacterium sp. pathogens. Most of them belonged to the Pseudomonas and Bacillus genera. In vitro assays revealed a fitness decrease of the tested Dickeya sp. and Pectobacterium sp. pathogens in the presence of the biocontrol agents. In addition, four independent greenhouse assays performed to evaluate the biocontrol bacteria effect on potato plants artificially contaminated with Dickeya dianthicola revealed that a mix of three biocontrol agents, namely, Pseudomonas putida PA14H7 and Pseudomonas fluorescens PA3G8 and PA4C2, repeatedly decreased the severity of blackleg symptoms as well as the transmission of D. dianthicola to the tuber progeny. This work highlights the use of a combination of biocontrol strains as a potential strategy to limit the soft rot and blackleg diseases caused by D. dianthicola on potato plants and tubers. PMID:26497457

Initial Reaction(s) in Biotransformation of CL-20 Is Catalyzed by Salicylate 1-Monooxygenase from Pseudomonas sp. Strain ATCC 29352

PubMed Central

Bhushan, Bharat; Halasz, Annamaria; Spain, Jim C.; Hawari, Jalal

2004-01-01

CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) (C6H6N12O12), a future-generation high-energy explosive, is biodegradable by Pseudomonas sp. strain FA1 and Agrobacterium sp. strain JS71; however, the nature of the enzyme(s) involved in the process was not understood. In the present study, salicylate 1-monooxygenase, a flavin adenine dinucleotide (FAD)-containing purified enzyme from Pseudomonas sp. strain ATCC 29352, biotransformed CL-20 at rates of 0.256 ± 0.011 and 0.043 ± 0.003 nmol min−1 mg of protein−1 under anaerobic and aerobic conditions, respectively. The disappearance of CL-20 was accompanied by the release of nitrite ions. Using liquid chromatography/mass spectrometry in the negative electrospray ionization mode, we detected a metabolite with a deprotonated mass ion [M − H]− at 345 Da, corresponding to an empirical formula of C6H6N10O8, produced as a result of two sequential N denitration steps on the CL- 20 molecule. We also detected two isomeric metabolites with [M − H]− at 381 Da corresponding to an empirical formula of C6H10N10O10. The latter was a hydrated product of the metabolite C6H6N10O8 with addition of two H2O molecules, as confirmed by tests using 18O-labeled water. The product stoichiometry showed that each reacted CL-20 molecule produced about 1.7 nitrite ions, 3.2 molecules of nitrous oxide, 1.5 molecules of formic acid, and 0.6 ammonium ion. Diphenyliodonium-mediated inhibition of salicylate 1-monooxygenase and a comparative study between native, deflavo, and reconstituted enzyme(s) showed that FAD site of the enzyme was involved in the biotransformation of CL-20 catalyzed by salicylate 1-monooxygenase. The data suggested that salicylate 1-monooxygenase catalyzed two oxygen-sensitive single-electron transfer steps necessary to release two nitrite ions from CL-20 and that this was followed by the secondary decomposition of this energetic chemical. PMID:15240281

Initial reaction(s) in biotransformation of CL-20 is catalyzed by salicylate 1-monooxygenase from Pseudomonas sp. strain ATCC 29352.

PubMed

Bhushan, Bharat; Halasz, Annamaria; Spain, Jim C; Hawari, Jalal

2004-07-01

CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) (C(6)H(6)N(12)O(12)), a future-generation high-energy explosive, is biodegradable by Pseudomonas sp. strain FA1 and Agrobacterium sp. strain JS71; however, the nature of the enzyme(s) involved in the process was not understood. In the present study, salicylate 1-monooxygenase, a flavin adenine dinucleotide (FAD)-containing purified enzyme from Pseudomonas sp. strain ATCC 29352, biotransformed CL-20 at rates of 0.256 +/- 0.011 and 0.043 +/- 0.003 nmol min(-1) mg of protein(-1) under anaerobic and aerobic conditions, respectively. The disappearance of CL-20 was accompanied by the release of nitrite ions. Using liquid chromatography/mass spectrometry in the negative electrospray ionization mode, we detected a metabolite with a deprotonated mass ion [M - H](-) at 345 Da, corresponding to an empirical formula of C(6)H(6)N(10)O(8), produced as a result of two sequential N denitration steps on the CL- 20 molecule. We also detected two isomeric metabolites with [M - H](-) at 381 Da corresponding to an empirical formula of C(6)H(10)N(10)O(10). The latter was a hydrated product of the metabolite C(6)H(6)N(10)O(8) with addition of two H(2)O molecules, as confirmed by tests using (18)O-labeled water. The product stoichiometry showed that each reacted CL-20 molecule produced about 1.7 nitrite ions, 3.2 molecules of nitrous oxide, 1.5 molecules of formic acid, and 0.6 ammonium ion. Diphenyliodonium-mediated inhibition of salicylate 1-monooxygenase and a comparative study between native, deflavo, and reconstituted enzyme(s) showed that FAD site of the enzyme was involved in the biotransformation of CL-20 catalyzed by salicylate 1-monooxygenase. The data suggested that salicylate 1-monooxygenase catalyzed two oxygen-sensitive single-electron transfer steps necessary to release two nitrite ions from CL-20 and that this was followed by the secondary decomposition of this energetic chemical.

Biosorption of heavy metals by Pseudomonas species isolated from sugar industry.

PubMed

Naz, Tayyaba; Khan, Muhammad Daud; Ahmed, Iftikhar; Rehman, Shafiq Ur; Rha, Eui Shik; Malook, Ijaz; Jamil, Muhammad

2016-09-01

Heavy metal-resistant bacteria can be efficient bioremediators of metals and may provide an alternative or additional method to conventional methods of metal removal. In this study, 10 bacterial isolates were isolated from soil samples of a sugar industry, located at Peshawar, Pakistan. Morphological, physiological, and biochemical characteristics of these isolates were observed. Sequence analysis (16S ribosomal RNA) revealed that isolated strains were closely related to the species belonging to the genera Pseudomonas, Arthrobacter, Exiguobacterium, Citrobacter, and Enterobacter Bacterial isolates were resistant with a minimum inhibitory concentration (500-900 ppm) to lead ion (Pb(2+)), (500-600 ppm) nickel ion (Ni(2+)), (500-800 ppm) copper ion (Cu(2+)), and (600-800 ppm) chromium ion (Cr(3+)) in solid media. Furthermore, biosorption of metals proved considerable removal of heavy metals by isolated metal-resistant strains. Pseudomonas sp. reduced 37% (Pb(2+)), 32% (Ni(2+)), 29% (Cu(2+)), and 32% (Cr(3+)) and was thus found to be most effective, whereas Enterobacter sp. reduced 19% (Pb(2+)), 7% (Ni(2+)), 14% (Cu(2+)), and 21% (Cr(3+)) and was found to be least effective. While average reduction of Pb(2+), Ni(2+), Cu(2+), and Cr(3+) by Citrobacter sp. was found to be 24%, 18%, 23%, and 27%, respectively, among recognized species. This study revealed that Pseudomonas sp. may provide a new microbial community that can be used for enhanced remediation of contaminated environment. © The Author(s) 2015.

The evaluation of the effect of body positioning on intra-abdominal pressure measurement and the effect of intra-abdominal pressure at different body positioning on organ function and prognosis in critically ill patients.

PubMed

Yi, Min; Leng, Yuxin; Bai, Yu; Yao, Gaiqi; Zhu, Xi

2012-04-01

Current literatures confirmed the widespread and frequent development of both intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) among the critically ill with a significant associated risk of organ failure and increased mortality. The 2004 International ACS Consensus Conference committee proposed that intra-abdominal pressure (IAP) be measured in complete supine position; however, the supine position of intensive care unit (ICU) patients (<30° of bed increase) presented a significant risk for ventilator-associated pneumonia. Therefore, the potential contribution of head of bed (HOB) position in elevating IAP should be considered. The purpose of this study was to evaluate the effect of body positioning on IAP measurement and the effect of IAP at different body positions on organ function and prognosis in critically ill patients. A prospective cohort study to investigate the effect of different patient positioning on IAP, organ function, and prognosis was conducted on 88 patients admitted to a medical-surgical ICU. On admission, patients' epidemiological data and risk factors for IAH were studied; daily mean IAPs, abdominal perfusion pressure, filtration gradient, Acute Physiology and Chronic Health Evaluation II score, sequential organ failure assessment score, and multiple organ dysfunction scores were registered; next, conventional hemodynamic variables, intrathoracic blood volume index, global end-diastolic volume index and extravascular lung water using the pulse contour cardiac output system were recorded. Intra-abdominal pressures were recorded through a bladder catheter every 4 hours on the first day. Intra-abdominal pressure was measured with the patient HOB increases from 0° to 45°. Mean arterial pressure was recorded simultaneously, whereas abdominal perfusion pressure and filtration gradient (FG) were also calculated simultaneously. The main results of this study were the incidence of IAH (28.4%) and ACS (2.3%) in ICU patients; the significant and independent relationship between IAP and HOB increases. Considering the absolute numbers of IAP, the HOB of 10° and 20° showed slight differences, whereas that of 30° and 45° showed clinically significant differences; HOB elevation was associated with clinically significant decreases in abdominal perfusion pressure and FG; patients with IAH were prone to the development of shock and multiple organ dysfunction syndrome and exhibited significantly lower intrathoracic blood volume index and global end-diastolic volume index and higher extravascular lung water. There is a significant and independent relationship between IAP and HOB positioning in critically ill patients, with the HOB of 30° and 45° showing significant difference. Abdominal perfusion pressure and FG are significantly decreased when the patient's HOB is elevated. The potential contribution of body position in elevating IAP should be considered in critically ill patients with the risk of IAH and ACS. Copyright © 2012 Elsevier Inc. All rights reserved.

[Antimicrobial sensitivity of the environmental microbiota in the intensive care units of a peruvian hospital].

PubMed

Díaz-Tello, José; Rojas-Jaimes, Jesús; Ibarra-Trujillo, Jimmy; Tárraga-Gonzales, Delza

2017-01-01

The objective was to detect Gram-negative bacilli and Gram-positive cocci isolated from the environmental microbiota of the Intensive Care Unit (ICU) departments of Neonatology, Pediatrics, and Transplants (kidney, liver, and general) in a Lima hospital and determine their antimicrobial sensitivity. Eighty samples were obtained from inanimate surfaces using a wet swab. A total of 61 bacterial strains were identified, including Staphylococcus epidermis (46.0%), Alcaligenes sp. (21.3%), Pseudomonas aeruginosa (16.4%), Acinetobacter sp. (13.1%), Staphylococcus aureus (1.6%), and Staphylococcus haemolyticus (1.6%). Acinetobacter sp. and P. aeruginosa showed a heightened sensitivity to the antibiotics assessed, while Alcaligenes sp. and S. epidermidis presented the highest antimicrobial resistance. It is recommended that sustained asepsis and monitoring methods be used in ICUs.

Isolation of amylolytic, xylanolytic, and cellulolytic microorganisms extracted from the gut of the termite Reticulitermes santonensis by means of a micro-aerobic atmosphere.

PubMed

Tarayre, Cédric; Brognaux, Alison; Bauwens, Julien; Brasseur, Catherine; Mattéotti, Christel; Millet, Catherine; Destain, Jacqueline; Vandenbol, Micheline; Portetelle, Daniel; De Pauw, Edwin; Eric, Haubruge; Francis, Frédéric; Thonart, Philippe

2014-05-01

The aim of this work was to isolate enzyme-producing microorganisms from the tract of the termite Reticulitermes santonensis. The microorganisms were extracted from the guts and anaerobic (CO₂ or CO₂/H₂) and micro-aerobic atmospheres were used to stimulate growth. Three different strategies were tried out. First, the sample was spread on Petri dishes containing solid media with carboxymethylcellulose, microcrystalline cellulose or cellobiose. This technique allowed us to isolate two bacteria: Streptomyces sp. strain ABGxAviA1 and Pseudomonas sp. strain ABGxCellA. The second strategy consisted in inoculating a specific liquid medium containing carboxymethylcellulose, microcrystalline cellulose, or cellobiose. The samples were then spread on Petri dishes with the same specific medium containing carboxymethylcellulose, microcrystalline cellulose, or cellobiose. This led to the isolation of the mold Aspergillus sp. strain ABGxAviA2. Finally, the third strategy consisted in heating the first culture and spreading samples on agar plates containing rich medium. This led to the isolation of the bacterium Bacillus subtilis strain ABGx. All those steps were achieved in controlled atmospheres. The four enzyme-producing strains which were isolated were obtained by using a micro-aerobic atmosphere. Later, enzymatic assays were performed on the four strains. Streptomyces sp. strain ABGxAviA1 was found to produce only amylase, while Pseudomonas sp. strain ABGxCellA was found to produce β-glucosidase as well. Aspergillus sp. strain ABGxAviA2 showed β-glucosidase, amylase, cellulase, and xylanase activities. Finally, B. subtilis strain ABGx produced xylanase and amylase.

Pseudomonas kribbensis sp. nov., isolated from garden soils in Daejeon, Korea.

PubMed

Chang, Dong-Ho; Rhee, Moon-Soo; Kim, Ji-Sun; Lee, Yookyung; Park, Mi Young; Kim, Haseong; Lee, Seung-Goo; Kim, Byoung-Chan

2016-11-01

Two bacterial strains, 46-1 and 46-2 T , were isolated from garden soil. These strains were observed to be aerobic, Gram-stain negative, rod-shaped, non-spore-forming, motile and catalase and oxidase positive. Phylogenetic analysis based on 16S rRNA gene sequences showed that the two strains shared 100 % sequence similarity with each other and belong to the genus Pseudomonas in the class Gammaproteobacteria. The concatenated 16S rRNA, gyrB, rpoB and rpoD gene sequences further confirmed that the isolates belong to the Pseudomonas koreensis subgroup (SG), with P. koreensis Ps 9-14 T , Pseudomonas moraviensis 1B4 T and Pseudomonas granadensis F-278,770 T as their close relatives (>96 % pairwise similarity). DNA-DNA hybridization with the closely related type strain P. koreensis SG revealed a low level of relatedness (<50 %). A cladogram constructed using whole-cell matrix-assisted laser desorption/ionization time-of-flight (WC-MALDI-TOF) MS analysis showed the isolates formed a completely separate monophyletic group. The isolates were negative for utilization of glycogen, D-psicose, α-keto butyric acid, α-keto valeric acid, succinamic acid and D, L-α-glycerol phosphate. In contrast, all these reactions were positive in P. koreensis JCM 14769 T and P. moraviensis DSM 16007 T . The fatty acid C 17:0 cyclo was detected as one of the major cellular fatty acids (>15 %) in the isolates but it was a minor component (<4 %) in both reference type strains. In contrast, the fatty acid, C 12:0 was not observed in the isolates but was present in both reference strains. Based on differences such as phylogenetic position, low-level DNA-DNA hybridization, WC-MALDI-TOF MS analysis, fluorescence pigmentation, fatty acid profiles, and substrate utilization, we propose that the isolates 46-1 and 46-2 T represent a novel species of the genus Pseudomonas, for which the name Pseudomonas kribbensis sp. nov. is proposed; the type strain is 46-2 T (=KCTC 32541 T  = DSM 100278 T ).

Pseudomonas sp. strain CA5 (a selenite-reducing bacterium) 16S rRNA gene complete sequence. National Institute of Health, National Center for Biotechnology Information, GenBank sequence. Accession FJ422810.1.

USDA-ARS?s Scientific Manuscript database

This study used 1321 base pair 16S rRNA gene sequence methods to confirm the phylogenetic position of a soil isolate as a bacterium belonging to the genus Pesudomonas sp. Morphological, biochemical characteristics, and fatty acid profiles are consistent with the 16S rRNA gene sequence identification...

Structure and mechanism of an inverting alkylsulfatase from Pseudomonas sp. DSM6611 specific for secondary alkyl sulfates.

PubMed

Knaus, Tanja; Schober, Markus; Kepplinger, Bernhard; Faccinelli, Martin; Pitzer, Julia; Faber, Kurt; Macheroux, Peter; Wagner, Ulrike

2012-12-01

A highly enantioselective and stereoselective secondary alkylsulfatase from Pseudomonas sp. DSM6611 (Pisa1) was heterologously expressed in Escherichia coli BL21, and purified to homogeneity for kinetic and structural studies. Structure determination of Pisa1 by X-ray crystallography showed that the protein belongs to the family of metallo-β-lactamases with a conserved binuclear Zn(2+) cluster in the active site. In contrast to a closely related alkylsulfatase from Pseudomonas aeruginosa (SdsA1), Pisa1 showed a preference for secondary rather than primary alkyl sulfates, and enantioselectively hydrolyzed the (R)-enantiomer of rac-2-octyl sulfate, yielding (S)-2-octanol with inversion of absolute configuration as a result of C-O bond cleavage. In order to elucidate the mechanism of inverting sulfate ester hydrolysis, for which no counterpart in chemical catalysis exists, we designed variants of Pisa1 guided by three-dimensional structure and docking experiments. In the course of these studies, we identified an invariant histidine (His317) near the sulfate-binding site as the general acid for crucial protonation of the sulfate leaving group. Additionally, amino acid replacements in the alkyl chain-binding pocket generated an enzyme variant that lost its stereoselectivity towards rac-2-octyl sulfate. These findings are discussed in light of the potential use of this enzyme family for applications in biocatalysis. © 2012 The Authors Journal compilation © 2012 FEBS.

Isolation and Molecular Characterization of a Model Antagonistic Pseudomonas aeruginosa Divulging In Vitro Plant Growth Promoting Characteristics.

PubMed

Uzair, Bushra; Kausar, Rehana; Bano, Syeda Asma; Fatima, Sammer; Badshah, Malik; Habiba, Ume; Fasim, Fehmida

2018-01-01

The use of microbial technologies in agriculture is currently expanding quite rapidly with the identification of new bacterial strains, which are more effective in promoting plant growth. In the present study 18 strains of Pseudomonas were isolated from soil sample of Balochistan coastline. Among isolated Pseudomonas strains four designated as SP19, SP22, PS24, and SP25 exhibited biocontrol activities against phytopathogenic fungi, that is, Rhizopus microsporus, Fusarium oxysporum, Aspergillus niger, Alternaria alternata, and Penicillium digitatum ; PS24 identified as Pseudomonas aeruginosa by 16srRNA gene bank accession number EU081518 was selected on the basis of its antifungal activity to explore its potential as plant growth promotion. PS24 showed multiple plant growth promoting attributes such as phosphate solubilization activity, indole acetic acid (IAA), siderophore, and HCN production. In order to determine the basis for antifungal properties, antibiotics were extracted from King B broth of PS24 and analyzed by TLC. Pyrrolnitrin antibiotic was detected in the culture of strain PS24. PS24 exhibited antifungal activities found to be positive for hydrogen cyanide synthase Hcn BC gene. Sequencing of gene of Hcn BC gene of strain PS24 revealed 99% homology with the Pseudomonas aeruginosa strain PA01 . The sequence of PS24 had been submitted in gene bank accession number KR605499. Ps. aeruginosa PS24 with its multifunctional biocontrol possessions can be used to bioprotect the crop plants from phytopathogens.

Effects of Organic Solvents on Indigo Formation by Pseudomonas sp. strain ST-200 Grown with High Levels of Indole.

PubMed

Doukyu, N; Arai, T; Aono, R

1998-01-01

The indole tolerance level of Pseudomonas sp. strain ST-200 was 0.25 mg/ml. The level was raised to 4 mg/ml when diphenylmethane was added to the medium to 20% by volume. ST-200 grown in this two-phase culture system containing indole (1 mg/ml) and diphenylmethane (0.2 ml/ml) produced a water-soluble yellow pigment, isatic acid, and two water-insoluble and diphenylmethane-soluble pigments, blue indigo and purple indirubin. The amounts of the water-insoluble pigments corresponded to 0.5% (indigo) and 0.2% (indirubin) of the indole added to the medium. Of the conditions tried, indigo and indirubin were formed only when ST-200 was grown in the two-phase system overlaid with organic solvents with appropriate polarity.

Pseudomonas japonica sp. nov., a novel species that assimilates straight chain alkylphenols.

PubMed

Pungrasmi, Wiboonluk; Lee, Haeng-Seog; Yokota, Akira; Ohta, Akinori

2008-02-01

A bacterial strain, WL(T), which was isolated from an activated sludge, was able to degrade alkylphenols. 16S rDNA sequence analysis indicated that strain WL(T) belonged to the genus Pseudomonas (sensu stricto) and formed a monophyletic clade with the type strain of Pseudomonas graminis and other members in the Pseudomonas putida subcluster with sequence similarity values higher than 97%. Genomic relatedness based on DNA-DNA hybridization of strain WL(T) to these strains is 2-41%. Strain WL(T) contained ubiquinone-9 as the main respiratory quinone, and the G+C content of DNA was 66 mol%. The organism contained hexadecanoic acid (16:0), hexadecenoic acid (16:1) and octadecenoic acid (18:1) as major cellular fatty acids. The hydroxy fatty acids detected were 3-hydroxydecanoic acid (3-OH 10:0), 3-hydroxydodecanoic acid (3-OH 12:0) and 2-hydroxydodecanoic acid (2-OH 12:0). These results, as well as physiological and biochemical characteristics clearly indicate that the strain WL(T) represents a new Pseudomonas species, for which the name Pseudomonas japonica is proposed. The type strain is strain WL(T) (=IAM 15071T=TISTR 1526T).

Assessment of the Diversity of Pseudomonas spp. and Fusarium spp. in Radix pseudostellariae Rhizosphere under Monoculture by Combining DGGE and Quantitative PCR

PubMed Central

Chen, Jun; Wu, Linkun; Xiao, Zhigang; Wu, Yanhong; Wu, Hongmiao; Qin, Xianjin; Wang, Juanying; Wei, Xiaoya; Khan, Muhammad U.; Lin, Sheng; Lin, Wenxiong

2017-01-01

Radix pseudostellariae is a perennial tonic medicinal plant, with high medicinal value. However, consecutive monoculture of this plant in the same field results in serious decrease in both yield and quality. In this study, a 3-year field experiment was performed to identify the inhibitory effect of growth caused by prolonged monoculture of R. pseudostellariae. DGGE analysis was used to explore the shifts in the structure and diversity of soil Fusarium and Pseudomonas communities along a 3-year gradient of monoculture. The results demonstrated that extended monoculture significantly boosted the diversity of Fusarium spp., but declined Pseudomonas spp. diversity. Quantitative PCR analysis showed a significant increase in Fusarium oxysporum, but a decline in Pseudomonas spp. Furthermore, abundance of antagonistic Pseudomonas spp. possessing antagonistic ability toward F. oxysporum significantly decreased in consecutively monocultured soils. Phenolic acid mixture at the same ratio as detected in soil could boost mycelial and sporular growth of pathogenic F. oxysporum while inhibit the growth of antagonistic Pseudomonas sp. CJ313. Moreover, plant bioassays showed that Pseudomonas sp. CJ313 had a good performance that protected R. pseudostellariae from infection by F. oxysporum. In conclusion, this study demonstrated that extended monoculture of R. pseudostellariae could alter the Fusarium and Pseudomonas communities in the plant rhizosphere, leading to relatively low level of antagonistic microorganisms, but with relatively high level of pathogenic microorganisms. PMID:28966607

Pseudomonas granadensis sp. nov., a new bacterial species isolated from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain.

PubMed

Pascual, Javier; García-López, Marina; Bills, Gerald F; Genilloud, Olga

2015-02-01

During the course of screening bacterial isolates as sources of as-yet unknown bioactive compounds with pharmaceutical applications, a chemo-organotrophic, Gram-negative bacterium was isolated from a soil sample taken from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain. Strain F-278,770(T) was oxidase- and catalase-positive, aerobic, with a respiratory type of metabolism with oxygen as the terminal electron acceptor, non-spore-forming and motile by one polar flagellum, although some cells had two polar flagella. Phylogenetic analysis of the 16S rRNA, gyrB, rpoB and rpoD genes revealed that strain F-278,770(T) belongs to the Pseudomonas koreensis subgroup (Pseudomonas fluorescens lineage), with Pseudomonas moraviensis, P. koreensis, P. baetica and P. helmanticensis as its closest relatives. Chemotaxonomic traits such as polar lipid and fatty acid compositions and G+C content of genomic DNA corroborated the placement of strain F-278,770(T) in the genus Pseudomonas. DNA-DNA hybridization assays and phenotypic traits confirmed that this strain represents a novel species of the genus Pseudomonas, for which the name Pseudomonas granadensis sp. nov. is proposed. The type strain is F-278,770(T) ( = DSM 28040(T) = LMG 27940(T)). © 2015 Fundacion MEDINA, Centro de Excelencia en Investigacion de Medicamentos Innovadores en Andalucia.

Borneol Dehydrogenase from Pseudomonas sp. Strain TCU-HL1 Catalyzes the Oxidation of (+)-Borneol and Its Isomers to Camphor

PubMed Central

Tsang, Hoi-Lung; Huang, Jui-Lin; Lin, Yu-Hsuan; Huang, Kai-Fa; Lu, Pei-Luen; Lin, Guang-Huey; Khine, Aye Aye; Hu, Anren

2016-01-01

ABSTRACT Most plant-produced monoterpenes can be degraded by soil microorganisms. Borneol is a plant terpene that is widely used in traditional Chinese medicine. Neither microbial borneol dehydrogenase (BDH) nor a microbial borneol degradation pathway has been reported previously. One borneol-degrading strain, Pseudomonas sp. strain TCU-HL1, was isolated by our group. Its genome was sequenced and annotated. The genome of TCU-HL1 consists of a 6.2-Mbp circular chromosome and one circular plasmid, pTHL1 (12.6 kbp). Our results suggest that borneol is first converted into camphor by BDH in TCU-HL1 and is further decomposed through a camphor degradation pathway. The recombinant BDH was produced in the form of inclusion bodies. The apparent Km values of refolded recombinant BDH for (+)-borneol and (−)-borneol were 0.20 ± 0.01 and 0.16 ± 0.01 mM, respectively, and the kcat values for (+)-borneol and (−)-borneol were 0.75 ± 0.01 and 0.53 ± 0.01 s−1, respectively. Two plant BDH genes have been reported previously. The kcat and kcat/Km values of lavender BDH are about 1,800-fold and 500-fold lower, respectively, than those of TCU-HL1 BDH. IMPORTANCE The degradation of borneol in a soil microorganism through a camphor degradation pathway is reported in this study. We also report a microbial borneol dehydrogenase. The kcat and kcat/Km values of lavender BDH are about 1,800-fold and 500-fold lower, respectively, than those of TCU-HL1 BDH. The indigenous borneol- and camphor-degrading strain isolated, Pseudomonas sp. strain TCU-HL1, reminds us of the time 100 years ago when Taiwan was the major producer of natural camphor in the world. PMID:27542933

Characterization of hydrocarbon-degrading and biosurfactant-producing Pseudomonas sp. P-1 strain as a potential tool for bioremediation of petroleum-contaminated soil.

PubMed

Pacwa-Płociniczak, Magdalena; Płaza, Grażyna Anna; Poliwoda, Anna; Piotrowska-Seget, Zofia

2014-01-01

The Pseudomonas sp. P-1 strain, isolated from heavily petroleum hydrocarbon-contaminated soil, was investigated for its capability to degrade hydrocarbons and produce a biosurfactant. The strain degraded crude oil, fractions A5 and P3 of crude oil, and hexadecane (27, 39, 27 and 13% of hydrocarbons added to culture medium were degraded, respectively) but had no ability to degrade phenanthrene. Additionally, the presence of gene-encoding enzymes responsible for the degradation of alkanes and naphthalene in the genome of the P-1 strain was reported. Positive results of blood agar and methylene blue agar tests, as well as the presence of gene rhl, involved in the biosynthesis of rhamnolipid, confirmed the ability of P-1 for synthesis of glycolipid biosurfactant. 1H and 13C nuclear magnetic resonance, Fourier transform infrared spectrum and mass spectrum analyses indicated that the extracted biosurfactant was affiliated with rhamnolipid. The results of this study indicate that the P-1 and/or biosurfactant produced by this strain have the potential to be used in bioremediation of hydrocarbon-contaminated soils.

Membrane-aerated biofilm reactor for the removal of 1,2-dichloroethane by Pseudomonas sp. strain DCA1.

PubMed

Hage, J C; Van Houten, R T; Tramper, J; Hartmans, S

2004-06-01

A membrane-aerated biofilm reactor (MBR) with a biofilm of Pseudomonas sp. strain DCA1 was studied for the removal of 1,2-dichloroethane (DCA) from water. A hydrophobic membrane was used to create a barrier between the liquid and the gas phase. Inoculation of the MBR with cells of strain DCA1 grown in a continuous culture resulted in the formation of a stable and active DCA-degrading biofilm on the membrane. The maximum removal rate of the MBR was reached at a DCA concentration of approximately 80 micro M. Simulation of the DCA fluxes into the biofilm showed that the MBR performance at lower concentrations was limited by the DCA diffusion rate rather than by kinetic constraints of strain DCA1. Aerobic biodegradation of DCA present in anoxic water could be achieved by supplying oxygen solely from the gas phase to the biofilm grown on the liquid side of the membrane. As a result, direct aeration of the water, which leads to undesired coagulation of iron oxides, could be avoided.

Analysis of Draft Genome Sequence of Pseudomonas sp. QTF5 Reveals Its Benzoic Acid Degradation Ability and Heavy Metal Tolerance

PubMed Central

Li, Yang; Ren, Yi

2017-01-01

Pseudomonas sp. QTF5 was isolated from the continuous permafrost near the bitumen layers in the Qiangtang basin of Qinghai-Tibetan Plateau in China (5,111 m above sea level). It is psychrotolerant and highly and widely tolerant to heavy metals and has the ability to metabolize benzoic acid and salicylic acid. To gain insight into the genetic basis for its adaptation, we performed whole genome sequencing and analyzed the resistant genes and metabolic pathways. Based on 120 published and annotated genomes representing 31 species in the genus Pseudomonas, in silico genomic DNA-DNA hybridization (<54%) and average nucleotide identity calculation (<94%) revealed that QTF5 is closest to Pseudomonas lini and should be classified into a novel species. This study provides the genetic basis to identify the genes linked to its specific mechanisms for adaptation to extreme environment and application of this microorganism in environmental conservation. PMID:29270429

Production and characterization of medium-chain-length polyhydroxyalkanoate copolymer from Arctic psychrotrophic bacterium Pseudomonas sp. PAMC 28620.

PubMed

Sathiyanarayanan, Ganesan; Bhatia, Shashi Kant; Song, Hun-Suk; Jeon, Jong-Min; Kim, Junyoung; Lee, Yoo Kyung; Kim, Yun-Gon; Yang, Yung-Hun

2017-04-01

Arctic psychrotrophic bacterium Pseudomonas sp. PAMC 28620 was found to produce a distinctive medium-chain-length polyhydroxyalkanoate (MCL-PHA) copolymer when grown on structurally unrelated carbon sources including glycerol. The maximum MCL-PHA copolymer yield was obtained about 52.18±4.12% from 7.95±0.66g/L of biomass at 144h of fermentation when 3% glycerol was used as sole carbon and energy source during the laboratory-scale bioreactor process. Characterization of the copolymer was carried out using fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS), proton ( 1 H) and carbon ( 13 C) nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), differential scanning calorimeter (DSC) and thermo-gravimetric analysis (TGA). The copolymer produced by Pseudomonas sp. PAMC 28620 consisting of four PHA monomers and identified as 3-hydroxyoctanoate (3HO), 3-hydroxydecanoate (3HD), 3-hydroxydodecanoate (3HDD) and 3-hydroxytetradecanoate (3HTD). An average molecular weight of the copolymer was found approximately 30.244kDa with polydispersity index (PDI) value of 2.05. Thermal analysis showed the produced MCL-PHA copolymer to be low-crystalline (43.73%) polymer with great thermal stability, having the thermal decomposition temperature of 230°C-280°C, endothermic melting temperature (T m ) of 172.84°C, glass transition (T g ) temperature of 3.99°C, and apparent melting enthalpy fusion (ΔH m ) about 63.85Jg -1 . Copyright © 2017 Elsevier B.V. All rights reserved.

Study on the biodegradation of crude oil by free and immobilized bacterial consortium in marine environment.

PubMed

Chen, Qingguo; Li, Jingjing; Liu, Mei; Sun, Huiling; Bao, Mutai

2017-01-01

Five strains of bacteria, namely, Exiguobacterium sp. ASW-1, Pseudomonas aeruginosa strain ASW-2, Alcaligenes sp. ASW-3, Alcaligenes sp. ASS-1, and Bacillus sp. ASS-2, were isolated from the Zhejiang coast in China. The mixed flora of the five strains performed well with degrading 75.1% crude oil (1%, w/v) in 7 days. The calcium alginate-activated carbon embedding carrier was used to immobilize bacterial consortium. Immobilized cells performed better than free ones in variations of environmental factors containing incubated temperature, initial pH, salinity of the medium and crude oil concentration. The degradation process of crude oil by immobilized bacteria was accelerated compared with that of the free ones. Bacterial consortium showed better performance on biodegradation of normal alkanes than that of PAHs. Improvement of immobilization on the biodegradation efficiency of normal alkanes (31.9%) was apparently high than that of PAHs (1.9%).

Study on the biodegradation of crude oil by free and immobilized bacterial consortium in marine environment

PubMed Central

Li, Jingjing; Liu, Mei; Sun, Huiling; Bao, Mutai

2017-01-01

Five strains of bacteria, namely, Exiguobacterium sp. ASW-1, Pseudomonas aeruginosa strain ASW-2, Alcaligenes sp. ASW-3, Alcaligenes sp. ASS-1, and Bacillus sp. ASS-2, were isolated from the Zhejiang coast in China. The mixed flora of the five strains performed well with degrading 75.1% crude oil (1%, w/v) in 7 days. The calcium alginate—activated carbon embedding carrier was used to immobilize bacterial consortium. Immobilized cells performed better than free ones in variations of environmental factors containing incubated temperature, initial pH, salinity of the medium and crude oil concentration. The degradation process of crude oil by immobilized bacteria was accelerated compared with that of the free ones. Bacterial consortium showed better performance on biodegradation of normal alkanes than that of PAHs. Improvement of immobilization on the biodegradation efficiency of normal alkanes (31.9%) was apparently high than that of PAHs (1.9%). PMID:28346510

Growth of Pseudomonas sp. TX1 on a wide range of octylphenol polyethoxylate concentrations and the formation of dicarboxylated metabolites.

PubMed

Lin, Yi-Wen; Guo, Gia-Luen; Hsieh, Hsiao-Cheng; Huang, Shir-Ly

2010-04-01

Pseudomonas sp. TX1, is able to use octylphenol polyethoxylates (OPEO(n), or Triton X-100; average n = 9.5) as a sole carbon source. It can grow on 0.05-20% of OPEO(n) with a specific growth rate of 0.34-0.44 h(-1). High-performance liquid chromatography-mass spectrometer analysis of OPEO(n) degraded metabolites revealed that strain TX1 was able to shorten the ethoxylate chain and produce octylphenol (OP). Furthermore, formation of the short carboxylate metabolites, such as carboxyoctylphenol polyethoxylates (COPEO(n), n = 2, 3) and carboxyoctylphenol polyethoxycarboxylates (COPEC(n), n = 2, 3) began at the log stage, while octylphenol polyethoxycarboxylates (OPEC(n), n = 1-3) was formed at the stationary phase. All the short-ethoxylated metabolites, OPEO(n), OPEC(n), COPEO(n), and COPEC(n), accumulated when the cells were in the stationary phase. This study is the first to demonstrate the formation of COPEO(n) and COPEC(n) from OPEO(n) by an aerobic bacterium. Copyright 2009 Elsevier Ltd. All rights reserved.

Chemical constituents of Aspergillus sp EJC08 isolated as endophyte from Bauhinia guianensis and their antimicrobial activity.

PubMed

Pinheiro, Eduardo A A; Carvalho, Josiwander M; Santos, Diellem C P dos; Feitosa, André O; Marinho, Patrícia S B; Guilhon, Giselle Maria S P; Santos, Lourivaldo S; Souza, Afonso L D de; Marinho, Andrey M R

2013-01-01

The present work reports the isolation of five compounds from Aspergillus sp EJC08 isolated as endophytic from Bauhinia guianensis, a tipical plant of the Amazon. The compounds ergosterol (1), ergosterol peroxide (2), mevalolactone (3), monomethylsulochrin (4) and trypacidin A (5) were isolated by chromatographic procedures and identified by spectral methods of 1D and 2D NMR and MS. Compounds 3, 4 and 5 were tested against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus and showed good activity.

Isolation and Identification of cellulolytic bacteria from mangrove sediment in Bangka Island

NASA Astrophysics Data System (ADS)

Kurniawan, A.; Prihanto, A. A.; Sari, S. P.; Febriyanti, D.; Kurniawan, A.; Sambah, A. B.; Asriani, E.

2018-04-01

Cellulolytic bacteria is bacteria which hydrolyze cellulose to reducing sugars. This research aims to obtain cellulolytic bacteria from the sediment of mangroves in Bangka island. Reasearch was conducted from March to August 2017. Sampling was conducted at Sungailiat, and Tukak Sadai, South of Bangka. Bacteria was isolated using 1% Carboxymetyl Cellulosa (CMC). The isolation resulted in four isolates from Sungailiat and nine isolates from Tukak Sadai. Total five isolates, namely Bacillus pumilus, Pseudomonas sp., Bacillus amyloliquefacien, Bacillus alvei, Bacillus coagulant were identified. The best isolates that produced cellulose was Pseudomonas aeruginosa.

Phospholipids and protein adaptation of Pseudomonas sp. to the xenoestrogen tributyltin chloride (TBT).

PubMed

Bernat, Przemysław; Siewiera, Paulina; Soboń, Adrian; Długoński, Jerzy

2014-09-01

A tributyltin (TBT)-resistant strain of Pseudomonas sp. isolated from an overworked car filter was tested for its adaptation to TBT. The isolate was checked for organotin degradation ability, as well as membrane lipid and cellular protein composition in the presence of TBT. The phospholipid profiles of bacteria, grown with and without increased amounts of TBT, were characterized using liquid chromatography/electrospray ionization/mass spectrometry. The strain reacted to the biocide by changing the composition of its phospholipids. TBT induced a twofold decline in the amounts of many molecular species of phosphatidylglycerol and an increase in the levels of phosphatidic acid (by 58%) and phosphatidylethanolamine (by 70%). An increase in the degree of saturation of phospholipid fatty acids of TBT exposed Pseudomonas sp. was observed. These changes in the phospholipid composition and concentration reflect the mechanisms which support optimal lipid ordering in the presence of toxic xenobiotic. In the presence of TBT the abundances of 16 proteins, including TonB-dependent receptors, porins and peroxidases were modified, which could indicate a contribution of some enzymes to TBT resistance.

Earthquakes Promote Bacterial Genetic Exchange in Serpentinite Crevices

NASA Astrophysics Data System (ADS)

Naoto, Yoshida; Fujiura, Nori

2009-04-01

We report the results of our efforts to study the effects of seismic shaking on simulated biofilms within serpentinite fissures. A colloidal solution consisting of recipient bacterial cells (Pseudomonas sp. or Bacillus subtilis), donor plasmid DNA encoded for antibiotic resistance, and chrysotile (an acicular clay mineral that forms in crevices of serpentinite layers) were placed onto an elastic body made from gellan gum, which acted as the biofilm matrix. Silica beads, as rock analogues (i.e., chemically inert mechanical serpentinite), were placed on the gellan surface, which was coated with the colloidal solution. A rolling vibration similar to vibrations generated by earthquakes was applied, and the silica beads moved randomly across the surface of the gellan. This resulted in the recipient cells' acquiring plasmid DNA and thus becoming genetically transformed to demonstrate marked antibiotic resistance. Neither Pseudomonas sp. nor B. subtilis were transformed by plasmid DNA when chrysotile was substituted for by kaolinite or bentonite in the colloidal solution. Tough gellan (1.0%) promoted the introduction of plasmid DNA into Pseudomonas sp., but soft gellan (0.3%) had no such effect. Genetic transformation of bacteria on the surface of gellan by exposure to exogenous plasmid DNA required seismic shaking and exposure to the acicular clay mineral chrysotile. These experimental results suggest that bacterial genetic exchange readily occurs when biofilms that form in crevices of serpentinite are exposed to seismic shaking. Seismic activity may be a key factor in bacterial evolution along with the formation of biofilms within crevices of serpentinite.

cis-chlorobenzene dihydrodiol dehydrogenase (TcbB) from Pseudomonas sp. strain P51, expressed in Escherichia coli DH5alpha(pTCB149), catalyzes enantioselective dehydrogenase reactions.

PubMed

Raschke, H; Fleischmann, T; Van Der Meer, J R; Kohler, H P

1999-12-01

cis-Chlorobenzene dihydrodiol dehydrogenase (CDD) from Pseudomonas sp. strain P51, cloned into Escherichia coli DH5alpha(pTCB149) was able to oxidize cis-dihydrodihydroxy derivatives (cis-dihydrodiols) of dihydronaphthalene, indene, and four para-substituted toluenes to the corresponding catechols. During the incubation of a nonracemic mixture of cis-1,2-indandiol, only the (+)-cis-(1R,2S) enantiomer was oxidized; the (-)-cis-(S,2R) enantiomer remained unchanged. CDD oxidized both enantiomers of cis-1,2-dihydroxy-1,2,3, 4-tetrahydronaphthalene, but oxidation of the (+)-cis-(1S,2R) enantiomer was delayed until the (-)-cis-(1R,2S) enantiomer was completely depleted. When incubated with nonracemic mixtures of para-substituted cis-toluene dihydrodiols, CDD always oxidized the major enantiomer at a higher rate than the minor enantiomer. When incubated with racemic 1-indanol, CDD enantioselectively transformed the (+)-(1S) enantiomer to 1-indanone. This stereoselective transformation shows that CDD also acted as an alcohol dehydrogenase. Additionally, CDD was able to oxidize (+)-cis-(1R,2S)-dihydroxy-1, 2-dihydronaphthalene, (+)-cis-monochlorobiphenyl dihydrodiols, and (+)-cis-toluene dihydrodiol to the corresponding catechols.

The role of the antimicrobial compound 2,4-diacetylphloroglucinol in the impact of biocontrol Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators.

PubMed

Couillerot, Olivier; Combes-Meynet, Emeline; Pothier, Joël F; Bellvert, Floriant; Challita, Elita; Poirier, Marie-Andrée; Rohr, René; Comte, Gilles; Moënne-Loccoz, Yvan; Prigent-Combaret, Claire

2011-06-01

Pseudomonads producing the antimicrobial metabolite 2,4-diacetylphloroglucinol (Phl) can control soil-borne phytopathogens, but their impact on other plant-beneficial bacteria remains poorly documented. Here, the effects of synthetic Phl and Phl(+) Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators were investigated. Most A. brasilense strains were moderately sensitive to Phl. In vitro, Phl induced accumulation of carotenoids and poly-β-hydroxybutyrate-like granules, cytoplasmic membrane damage and growth inhibition in A. brasilense Cd. Experiments with P. fluorescens F113 and a Phl(-) mutant indicated that Phl production ability contributed to in vitro growth inhibition of A. brasilense Cd and Sp245. Under gnotobiotic conditions, each of the three strains, P. fluorescens F113 and A. brasilense Cd and Sp245, stimulated wheat growth. Co-inoculation of A. brasilense Sp245 and Pseudomonas resulted in the same level of phytostimulation as in single inoculations, whereas it abolished phytostimulation when A. brasilense Cd was used. Pseudomonas Phl production ability resulted in lower Azospirillum cell numbers per root system (based on colony counts) and restricted microscale root colonization of neighbouring Azospirillum cells (based on confocal microscopy), regardless of the A. brasilense strain used. Therefore, this work establishes that Phl(+) pseudomonads have the potential to interfere with A. brasilense phytostimulators on roots and with their plant growth promotion capacity.

The Complete Genome Sequence of the Plant Growth-Promoting Bacterium Pseudomonas sp. UW4

PubMed Central

Duan, Jin; Jiang, Wei; Cheng, Zhenyu; Heikkila, John J.; Glick, Bernard R.

2013-01-01

The plant growth-promoting bacterium (PGPB) Pseudomonas sp. UW4, previously isolated from the rhizosphere of common reeds growing on the campus of the University of Waterloo, promotes plant growth in the presence of different environmental stresses, such as flooding, high concentrations of salt, cold, heavy metals, drought and phytopathogens. In this work, the genome sequence of UW4 was obtained by pyrosequencing and the gaps between the contigs were closed by directed PCR. The P. sp. UW4 genome contains a single circular chromosome that is 6,183,388 bp with a 60.05% G+C content. The bacterial genome contains 5,423 predicted protein-coding sequences that occupy 87.2% of the genome. Nineteen genomic islands (GIs) were predicted and thirty one complete putative insertion sequences were identified. Genes potentially involved in plant growth promotion such as indole-3-acetic acid (IAA) biosynthesis, trehalose production, siderophore production, acetoin synthesis, and phosphate solubilization were determined. Moreover, genes that contribute to the environmental fitness of UW4 were also observed including genes responsible for heavy metal resistance such as nickel, copper, cadmium, zinc, molybdate, cobalt, arsenate, and chromate. Whole-genome comparison with other completely sequenced Pseudomonas strains and phylogeny of four concatenated “housekeeping” genes (16S rRNA, gyrB, rpoB and rpoD) of 128 Pseudomonas strains revealed that UW4 belongs to the fluorescens group, jessenii subgroup. PMID:23516524

Antibacterial metabolites synthesized by psychrotrophic bacteria isolated from cold-freshwater environments.

PubMed

Barros, Javier; Becerra, José; González, Carlos; Martínez, Miguel

2013-03-01

The ability of three psychrotrophic Gram-negative bacilli isolated from Chilean Patagonian cold freshwater rivers to produce bioactive metabolites was evaluated. The strains were isolated from cold waters rivers and identified by their biochemical properties and 16S rRNA gene analysis. The metabolites fractions showing antibacterial activity were obtained by solvent extraction and partially characterized by gas-mass chromatography (GC-MS). Antibacterial activity of the fractions was evaluated by an agar-well diffusion test upon 14 bacterial strains, both Gram positive and Gram negative. Thermal and proteolytic resistances of the antibacterial metabolites fractions were also evaluated. Molecular analysis allows the identification of the three Patagonian strains as Pseudomonas sp. RG-6 (Pseudomonas brenneri 99.6 % identity), Pseudomonas sp. RG-8 (Pseudomonas trivialis 99.6 % identity) and Yersinia sp. RP-3 (Yersinia aldovae 99.5 % identity). These extracts were able to inhibit both Gram-positive and Gram-negative bacteria but not Listeria monocytogenes. The antibacterial activity of the filtrated supernatants was lost at temperatures ≥60 °C, and was not affected by proteinase K treatment. The chemical structure of the active molecule remains to be elucidated, although the GC-MS analysis of the filtrates suggests that compounds like sesquiterpenes derivatives from β-maaliene or δ-selinene could be responsible of this antibacterial activity. Pristine cold freshwater streams showed to be interesting sources of metabolites-producing microorganisms with antibacterial activity.

Induced systemic resistance: a delicate balance

USDA-ARS?s Scientific Manuscript database

Pseudomonas sp. strain CMR12a produces phenazine-1-carboxamide and two cyclic lipopeptides, sessilin and viscosinamide. In this highlight of the recent work with this strain by Monica Höfte of Ghent University, Belgium, I review recent studies showing that the metabolites produced by CMR12a interact...

Biodegradation of the organophosphorus insecticide diazinon by Serratia sp. and Pseudomonas sp. and their use in bioremediation of contaminated soil.

PubMed

Cycoń, Mariusz; Wójcik, Marcin; Piotrowska-Seget, Zofia

2009-07-01

An enrichment culture technique was used for the isolation of bacteria responsible for biodegradation of diazinon in soil. Three bacterial strains were screened and identified by MIDI-FAME profiling as Serratia liquefaciens, Serratia marcescens and Pseudomonas sp. All isolates were able to grow in mineral salt medium (MSM) supplemented with diazinon (50 mgL(-1)) as a sole carbon source, and within 14d 80-92% of the initial dose of insecticide was degraded by the isolates and their consortium. Degradation of diazinon was accelerated when MSM was supplemented with glucose. However, this process was linked with the decrease of pH values, after glucose utilization. Studies on biodegradation in sterilized soil showed that isolates and their consortium exhibited efficient degradation of insecticide (100mg kg(-1) soil) with a rate constant of 0.032-0.085d(-1), and DT(50) for diazinon was ranged from 11.5d to 24.5d. In contrast, degradation of insecticide in non-sterilized soil, non-supplemented earlier with diazinon, was characterized by a rate constant of 0.014d(-1) and the 7-d lag phase, during which only 2% of applied dose was degraded. The results suggested a strong correlation between microbial activity and chemical processes during diazinon degradation. Moreover, isolated bacterial strains may have potential for use in bioremediation of diazinon-contaminated soils.

Biodegradation analyses of trichloroethylene (TCE) by bacteria and its use for biosensing of TCE.

PubMed

Chee, Gab-Joo

2011-09-30

Trichloroethylene (TCE) is a toxic, recalcitrant groundwater pollutant. TCE-degrading microorganisms were isolated from various environments. The aerobic bacteria isolated from toluene- and tryptophan-containing media were Pseudomonas sp. strain ASA86 and Burkholderia sp. strain TAM17, respectively; these are necessary for inducing TCE biodegradation in a selective medium. The half-degradation time of TCE to a concentration of 1mg/L was 18 h for strain ASA86 and 7 days for strain TAM17. While identifying toluene/TCE degradation genes, we found that in strain ASA86, the gene was the same as the todC1 gene product encoding toluene dioxygenase identified in Pseudomonas putida F1, and that in strain TAM17, the gene was similar to the tecA1 gene product encoding chlorobenzene dioxygenase identified in Burkholderia sp. PS12. A novel TCE biosensor was developed using strain ASA86 as the inducer of toluene under aerobic conditions. The TCE biosensor exhibited a linear relationship below 3 ppm TCE. Detection limit of the biosensor was 0.05 ppm TCE. The response time of the biosensor was less than 10 min. The biosensor response displayed a constant level during a 2 day period. The TCE biosensor displayed sufficient sensitivity for monitoring TCE in environmental systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of Granulocyte-Colony Stimulating Factor on Endothelial Cells and Osteoblasts

PubMed Central

Liu, Xi Ling; Hu, Xiang; Cai, Wei Xin; Lu, Weijia William; Zheng, Li Wu

2016-01-01

Objectives. Some animal studies showed that granulocyte-colony stimulating factor (G-CSF) provides beneficial environment for bone healing. It has been well documented that endothelial cells and osteoblasts play critical roles in multiple phases of bone healing. However, the biological effects of G-CSF on these cells remain controversial. This study aimed to investigate the influence of G-CSF at various concentrations on endothelial cells and osteoblasts. Materials and Methods. Human umbilical vein endothelial cells (HUVECs) and human osteoblasts (hOBs) were treated with G-CSF at 1000, 100, 10, and 0 ng/mL, respectively. The capacity of cell proliferation, migration, and tube formation of HUVECs was evaluated at 72, 8, and 6 hours after treatment, respectively. The capacity of proliferation, differentiation, and mineralization of hOBs was evaluated at 24 hours, 72 hours, and 21 days after treatment, respectively. Results. HUVECs treated with 100 and 1000 ng/mL G-CSF showed a significantly higher value comparing with controls in migration assay (p < 0.001, p < 0.01, resp.); the group treated with 1000 ng/mL G-CSF showed a significantly lower value on tube formation. No significant difference was detected in groups of hOBs. Conclusions. G-CSF showed favorable effects only on the migration of HUVECs, and no direct influence was found on hOBs. PMID:27006951

Strengthen effects of dominant strains on aerobic digestion and stabilization of the residual sludge.

PubMed

Liu, Yongjun; Gao, Min; Zhang, Aining; Liu, Zhe

2017-07-01

In order to strengthen the aerobic digestion of residual sludge, shorten the time of sludge stabilization and further reduce operating costs, 3 dominant strains identified as Pseudomonas sp. L3, Acinetobacter sp. L16 and Bacillus sp. L19 were isolated from long-term aerobic digestion sludge. Results showed that the sludge stabilization time were reduced by 3-4days compared with the control when the dominant strains were added to the process of sludge aerobic digestion. The addition of dominant strains accelerated the accumulation of TOC, nitrate nitrogen and ammonia nitrogen in the digestive solution at different levels, and it was beneficial to the dissolution of phosphorus. Controlling DO 3-5mg/L, pH 6.5, the strains of Pseudomonas sp. L3 and Bacillus sp. L19 were combined dosing with the dosage of 2% in the process of sludge aerobic digestion, compared with the control, digestion rates of TOC and MLSS were increased about 19% and 16%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Extracellular polysaccharides produced by cooling water tower biofilm bacteria and their possible degradation.

PubMed

Ceyhan, Nur; Ozdemir, Guven

2008-01-01

The extracellular polymers (EPS) of biofilm bacteria that can cause heat and mass transfer problems in cooling water towers in the petrochemical industry were investigated. In addition, these microorganisms were screened for their ability to grow and degrade their own EPS and the EPS of other species. Twelve bacteria producing the most EPS were isolated from cooling water towers and characterized biochemically by classic and commercial systems. These were species of Pseudomonas, Burkholderia, Aeromonas, Pasteurella, Pantoea, Alcaligenes and Sphingomonas. EPS of these species were obtained by propan-2-ol precipitation and centrifugation from bacterial cultures in media enriched with glucose, sucrose or galactose. EPS yields were of 1.68-4.95 g l(-1). These EPS materials were characterized for total sugar and protein contents. Their total sugar content ranged from 24 to 56% (g sugar g(-1) EPS), and their total protein content ranged from 10 to 28% (g protein g(-1) EPS). The monosaccharide compositions of EPS were determined by HPLC. Generally, these compositions were enriched in galactose and glucose, with lesser amounts of mannose, rhamnose, fructose and arabinose. All bacteria were investigated in terms of EPS degradation. Eight of the bacteria were able to utilize EPS from Burkholderia cepacia, seven of the bacteria were able to utilize EPS from Pseudomonas sp. and Sphingomonas paucimobilis. The greatest viscosity reduction of B. cepacia was obtained with Pseudomonas sp. The results show that the bacteria in this study are able to degrade EPS from biofilms in cooling towers.

Microbial Culturomics Application for Global Health: Noncontiguous Finished Genome Sequence and Description of Pseudomonas massiliensis Strain CB-1T sp. nov. in Brazil.

PubMed

Bardet, Lucie; Cimmino, Teresa; Buffet, Clémence; Michelle, Caroline; Rathored, Jaishriram; Tandina, Fatalmoudou; Lagier, Jean-Christophe; Khelaifia, Saber; Abrahão, Jônatas; Raoult, Didier; Rolain, Jean-Marc

2018-02-01

Culturomics is a new postgenomics field that explores the microbial diversity of the human gut coupled with taxono-genomic strategy. Culturomics, and the microbiome science more generally, are anticipated to transform global health diagnostics and inform the ways in which gut microbial diversity contributes to human health and disease, and by extension, to personalized medicine. Using culturomics, we report in this study the description of strain CB1 T ( = CSUR P1334 = DSM 29075), a new species isolated from a stool specimen from a 37-year-old Brazilian woman. This description includes phenotypic characteristics and complete genome sequence and annotation. Strain CB1 T is a gram-negative aerobic and motile bacillus, exhibits neither catalase nor oxidase activities, and presents a 98.3% 16S rRNA sequence similarity with Pseudomonas putida. The 4,723,534 bp long genome contains 4239 protein-coding genes and 74 RNA genes, including 15 rRNA genes (5 16S rRNA, 4 23S rRNA, and 6 5S rRNA) and 59 tRNA genes. Strain CB1 T was named Pseudomonas massiliensis sp. nov. and classified into the family Pseudomonadaceae. This study demonstrates the usefulness of microbial culturomics in exploration of human microbiota in diverse geographies and offers new promise for incorporating new omics technologies for innovation in diagnostic medicine and global health.

A novel lignin degradation bacterial consortium for efficient pulping.

PubMed

Wang, Yanxia; Liu, Quan; Yan, Lei; Gao, Yamei; Wang, Yanjie; Wang, Weidong

2013-07-01

A lignin degradation bacterial consortium named LDC was screened from the sludge of a reeds pond by a restricted subculture. It could break down 60.9% lignin in reeds at 30°C under conditions of static culture within 15 days. In order to analyze the diversity of LDC, plate isolation, 16S rDNA clone library and ARDRA (Amplified Ribosomal DNA Restriction Analysis) were performed. Six bacterial strains were isolated from LDC and eighteen DNA phylotypes were identified from 230 bacterial analyzed clones. They were classified into Clostridiales(9.1%), Geovibrio thiophilus (5.1%), Desulfomicrobium (10.9%), Pseudomonas sp. (25.2%), Azoarcus sp. (5.1%), Thauera (5.1%), Paenibacillus sp. (5.1%), Cohnella sp. (2.2%), Acinetobacter sp. (3.1%), Microbacterium (7.8%), and uncultured bacterium (21.3%). In addition, physical characteristics of paper hand-sheets between biological pretreatment and chemical pretreatment were compared. The results showed that LDC had the capability of lignin degradation and was efficient for pulping, which would provide a new choice for biopulping. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Analysis of DNA-DNA homologies in obligate methylotrophic bacteria].

PubMed

Doronina, N V; Govorukhina, N I; Lysenko, A M; Trotsenko, Iu A

1988-01-01

The genotypic affinity of 19 bacterial strains obligately dependent on methanol or methylamine as carbon and energy sources was studied by techniques of molecular DNA hybridization. The high homology level (35-88%) between motile strain Methylophilus methanolovorus V-1447D and nonmotile strain Methylobacillus sp. VSB-792 as well as other motile strains (Pseudomonas methanolica ATCC 21704, Methylomonas methanolica NRRL 5458, Pseudomonas sp. W6, strain A3) indicates that all of them belong to one genus. Rather high level of homology (62-63%) was found between Methylobacillus glycogenes ATCC 29475 and Pseudomonas insueta ATCC 21276 and strain G-10. The motile strain Methylophilus methylotrophus NCIB 10515 has a low homology (below 20%) to other of the studied obligate methylobacteria. Therefore, at least two genetically different genera of obligate methylobacteria can be distinguished, namely Methylophilus and Methylobacillus, the latter being represented by both motile and nonmotile forms.

Draft Genome Sequence of Pseudomonas sp. BDAL1 Reconstructed from a Bakken Shale Hydraulic Fracturing-Produced Water Storage Tank Metagenome

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

Lipus, Daniel; Ross, Daniel; Bibby, Kyle

We report the 5,425,832 bp draft genome ofPseudomonassp. strain BDAL1, recovered from a Bakken shale hydraulic fracturing-produced water tank metagenome. Genome annotation revealed several key biofilm formation genes and osmotic stress response mechanisms necessary for survival in hydraulic fracturing-produced water.

Draft Genome Sequence of Pseudomonas sp. BDAL1 Reconstructed from a Bakken Shale Hydraulic Fracturing-Produced Water Storage Tank Metagenome

DOE PAGES

Lipus, Daniel; Ross, Daniel; Bibby, Kyle; ...

2017-03-16

We report the 5,425,832 bp draft genome ofPseudomonassp. strain BDAL1, recovered from a Bakken shale hydraulic fracturing-produced water tank metagenome. Genome annotation revealed several key biofilm formation genes and osmotic stress response mechanisms necessary for survival in hydraulic fracturing-produced water.

Water-soluble Moringa oleifera lectin interferes with growth, survival and cell permeability of corrosive and pathogenic bacteria.

PubMed

Moura, M C; Napoleão, T H; Coriolano, M C; Paiva, P M G; Figueiredo, R C B Q; Coelho, L C B B

2015-09-01

This work evaluated the antibacterial activity of a water-soluble Moringa oleifera seed lectin (WSMoL) by evaluating its effect on growth, survival and cell permeability of Bacillus sp., Bacillus cereus, Bacillus pumillus, Bacillus megaterium, Micrococcus sp., Pseudomonas sp., Pseudomonas fluorescens, Pseudomonas stutzeri and Serratia marcescens. In addition, the effect of lectin on membrane integrity of most sensitive species was also evaluated. All the tested bacteria are able to cause biocorrosion and some are also responsible for human infections. WSMoL inhibited the bacterial growth, induced agglutination and promoted the leakage of proteins from cells of all strains. Bactericidal effect was detected against Bacillus sp., B. pumillus, B. megaterium, Ps. fluorescens and Ser. marcescens. The bacteriostatic effect of lectin was evident with only 6 h of incubation. Fluorescence microscopy of Ser. marcescens showed that WSMoL caused loss of cell integrity and indicated an anti-biofilm activity of the lectin. WSMoL was active against the bacteria by inhibiting growth and affecting cell permeability. The lectin also interfered with membrane integrity of Ser. marcescens, the most sensitive species. The study indicates that WSMoL was active against bacteria that cause serious problems in both industrial and health sectors. Also, the study contributes for the 'state-of-art' on antibacterial mechanisms of lectins. © 2015 The Society for Applied Microbiology.

Synergistic Degradation of Linuron by a Bacterial Consortium and Isolation of a Single Linuron-Degrading Variovorax Strain

PubMed Central

Dejonghe, Winnie; Berteloot, Ellen; Goris, Johan; Boon, Nico; Crul, Katrien; Maertens, Siska; Höfte, Monica; De Vos, Paul; Verstraete, Willy; Top, Eva M.

2003-01-01

The bacterial community composition of a linuron-degrading enrichment culture and the role of the individual strains in linuron degradation have been determined by a combination of methods, such as denaturing gradient gel electrophoresis of the total 16S rRNA gene pool, isolation and identification of strains, and biodegradation assays. Three strains, Variovorax sp. strain WDL1, Delftia acidovorans WDL34, and Pseudomonas sp. strain WDL5, were isolated directly from the linuron-degrading culture. In addition, subculture of this enrichment culture on potential intermediates in the degradation pathway of linuron (i.e., N,O-dimethylhydroxylamine and 3-chloroaniline) resulted in the isolation of, respectively, Hyphomicrobium sulfonivorans WDL6 and Comamonas testosteroni WDL7. Of these five strains, only Variovorax sp. strain WDL1 was able to use linuron as the sole source of C, N, and energy. WDL1 first converted linuron to 3,4-dichloroaniline (3,4-DCA), which transiently accumulated in the medium but was subsequently degraded. To the best of our knowledge, this is the first report of a strain that degrades linuron further than the aromatic intermediates. Interestingly, the rate of linuron degradation by strain WDL1 was lower than that for the consortium, but was clearly increased when WDL1 was coinoculated with each of the other four strains. D. acidovorans WDL34 and C. testosteroni WDL7 were found to be responsible for degradation of the intermediate 3,4-DCA, and H. sulfonivorans WDL6 was the only strain able to degrade N,O-dimethylhydroxylamine. The role of Pseudomonas sp. strain WDL5 needs to be further elucidated. The degradation of linuron can thus be performed by a single isolate, Variovorax sp. strain WDL1, but is stimulated by a synergistic interaction with the other strains isolated from the same linuron-degrading culture. PMID:12620840

Hydrolysis of lignocellulosic feedstock by novel cellulases originating from Pseudomonas sp. CL3 for fermentative hydrogen production.

PubMed

Cheng, Chieh-Lun; Chang, Jo-Shu

2011-09-01

A newly isolated indigenous bacterium Pseudomonas sp. CL3 was able to produce novel cellulases consisting of endo-β-1,4-d-glucanase (80 and 100 kDa), exo-β-1,4-d-glucanase (55 kDa) and β-1,4-d-glucosidase (65 kDa) characterized by enzyme assay and zymography analysis. In addition, the CL3 strain also produced xylanase with a molecular weight of 20 kDa. The optimal temperature for enzyme activity was 50, 45, 45 and 55 °C for endo-β-1,4-d-glucanase, exo-β-1,4-d-glucanase, β-1,4-d-glucosidase and xylanase, respectively. All the enzymes displayed optimal activity at pH 6.0. The cellulases/xylanase could hydrolyze cellulosic materials very effectively and were thus used to hydrolyze natural agricultural waste (i.e., bagasse) for clean energy (H2) production by Clostridium pasteurianum CH4 using separate hydrolysis and fermentation process. The maximum hydrogen production rate and cumulative hydrogen production were 35 ml/L/h and 1420 ml/L, respectively, with a hydrogen yield of around 0.96 mol H2/mol glucose. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Nitrogen-Fixation Island Insertion Site Is Conserved in Diazotrophic Pseudomonas stutzeri and Pseudomonas sp. Isolated from Distal and Close Geographical Regions

PubMed Central

Venieraki, Anastasia; Dimou, Maria; Vezyri, Eleni; Vamvakas, Alexandros; Katinaki, Pagona-Artemis; Chatzipavlidis, Iordanis; Tampakaki, Anastasia; Katinakis, Panagiotis

2014-01-01

The presence of nitrogen fixers within the genus Pseudomonas has been established and so far most isolated strains are phylogenetically affiliated to Pseudomonas stutzeri. A gene ortholog neighborhood analysis of the nitrogen fixation island (NFI) in four diazotrophic P. stutzeri strains and Pseudomonas azotifigens revealed that all are flanked by genes coding for cobalamin synthase (cobS) and glutathione peroxidise (gshP). The putative NFIs lack all the features characterizing a mobilizable genomic island. Nevertheless, bioinformatic analysis P. stutzeri DSM 4166 NFI demonstrated the presence of short inverted and/or direct repeats within both flanking regions. The other P. stutzeri strains carry only one set of repeats. The genetic diversity of eleven diazotrophic Pseudomonas isolates was also investigated. Multilocus sequence typing grouped nine isolates along with P. stutzeri and two isolates are grouped in a separate clade. A Rep-PCR fingerprinting analysis grouped the eleven isolates into four distinct genotypes. We also provided evidence that the putative NFI in our diazotrophic Pseudomonas isolates is flanked by cobS and gshP genes. Furthermore, we demonstrated that the putative NFI of Pseudomonas sp. Gr65 is flanked by inverted repeats identical to those found in P. stutzeri DSM 4166 and while the other P. stutzeri isolates harbor the repeats located in the intergenic region between cobS and glutaredoxin genes as in the case of P. stutzeri A1501. Taken together these data suggest that all putative NFIs of diazotrophic Pseudomonas isolates are anchored in an intergenic region between cobS and gshP genes and their flanking regions are designated by distinct repeats patterns. Moreover, the presence of almost identical NFIs in diazotrophic Pseudomonas strains isolated from distal geographical locations around the world suggested that this horizontal gene transfer event may have taken place early in the evolution. PMID:25251496

The nitrogen-fixation island insertion site is conserved in diazotrophic Pseudomonas stutzeri and Pseudomonas sp. isolated from distal and close geographical regions.

PubMed

Venieraki, Anastasia; Dimou, Maria; Vezyri, Eleni; Vamvakas, Alexandros; Katinaki, Pagona-Artemis; Chatzipavlidis, Iordanis; Tampakaki, Anastasia; Katinakis, Panagiotis

2014-01-01

The presence of nitrogen fixers within the genus Pseudomonas has been established and so far most isolated strains are phylogenetically affiliated to Pseudomonas stutzeri. A gene ortholog neighborhood analysis of the nitrogen fixation island (NFI) in four diazotrophic P. stutzeri strains and Pseudomonas azotifigens revealed that all are flanked by genes coding for cobalamin synthase (cobS) and glutathione peroxidise (gshP). The putative NFIs lack all the features characterizing a mobilizable genomic island. Nevertheless, bioinformatic analysis P. stutzeri DSM 4166 NFI demonstrated the presence of short inverted and/or direct repeats within both flanking regions. The other P. stutzeri strains carry only one set of repeats. The genetic diversity of eleven diazotrophic Pseudomonas isolates was also investigated. Multilocus sequence typing grouped nine isolates along with P. stutzeri and two isolates are grouped in a separate clade. A Rep-PCR fingerprinting analysis grouped the eleven isolates into four distinct genotypes. We also provided evidence that the putative NFI in our diazotrophic Pseudomonas isolates is flanked by cobS and gshP genes. Furthermore, we demonstrated that the putative NFI of Pseudomonas sp. Gr65 is flanked by inverted repeats identical to those found in P. stutzeri DSM 4166 and while the other P. stutzeri isolates harbor the repeats located in the intergenic region between cobS and glutaredoxin genes as in the case of P. stutzeri A1501. Taken together these data suggest that all putative NFIs of diazotrophic Pseudomonas isolates are anchored in an intergenic region between cobS and gshP genes and their flanking regions are designated by distinct repeats patterns. Moreover, the presence of almost identical NFIs in diazotrophic Pseudomonas strains isolated from distal geographical locations around the world suggested that this horizontal gene transfer event may have taken place early in the evolution.

Trans-membrane transport of n-octadecane by Pseudomonas sp. DG17.

PubMed

Hua, Fei; Wang, Hong Qi; Li, Yi; Zhao, Yi Cun

2013-12-01

The trans-membrane transport of hydrocarbons is an important and complex aspect of the process of biodegradation of hydrocarbons by microorganisms. The mechanism of transport of (14)C n-octadecane by Pseudomonas sp. DG17, an alkane-degrading bacterium, was studied by the addition of ATP inhibitors and different substrate concentrations. When the concentration of n-octadecane was higher than 4.54 μmol/L, the transport of (14)C n-octadecane was driven by a facilitated passive mechanism following the intra/extra substrate concentration gradient. However, when the cells were grown with a low concentration of the substrate, the cellular accumulation of n-octadecane, an energy-dependent process, was dramatically decreased by the presence of ATP inhibitors, and n-octadecane accumulation continually increased against its concentration gradient. Furthermore, the presence of non-labeled alkanes blocked (14)C n-octadecane transport only in the induced cells, and the trans-membrane transport of n-octadecane was specific with an apparent dissociation constant K t of 11.27 μmol/L and V max of 0.96 μmol/min/mg protein. The results indicated that the trans-membrane transport of n-octadecane by Pseudomonas sp. DG17 was related to the substrate concentration and ATP.

Isolation and complementation analysis of 10 methanol oxidation mutant classes and identification of the methanol dehydrogenase structural gene of Methylobacterium sp. strain AM1

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

Nunn, D.N.; Lidstrom, M.E.

A method has been developed for the direct selection of methanol oxidation mutants of the facultative methylotroph Methylobacterium sp. strain AM1 (formerly Pseudomonas sp. strain AM1). Using this direct selection technique, we have isolated mutants of Methylobacterium sp. strain AM1 that are no longer capable of growth on methanol but retain the ability to grow on methylamine. These methanol oxidation (Mox) mutants were complemented with a genomic clone bank of this organism constructed in the broad-host-range cosmid pVK100, and subcloning and Tn5 mutagenesis experiments have assigned the Mox mutants to 10 distinct complementation groups. Using an open reading frame beta-galactosidasemore » fusion vector and antibodies specific for Methylobacterium sp. strain AM1 methanol dehydrogenase, we have identified the methanol dehydrogenase structural gene and determined the direction of transcription. The results suggest that the synthesis and utilization of an active methanol dehydrogenase in this organism requires at least 10 different gene functions.« less

Influence of calcium, iron and pH on phosphate availability for microbial mineralization of organic chemicals

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

Robertson, B.K.; Alexander, M.

1992-01-01

A study was conducted to determine some of the factors affecting the P requirement for the biodegradation of p-nitrophenol, phenol, and glucose by Pseudomonas and Corynebacterium strains. Mineralization of glucose was rapid and the Pseudomonas sp. grew extensively in solutions with 5 and 10 mM phosphate, but the rate and extent of degradation were low and the bacterial population never became abundant in media with 0.2 mM phosphate. Similar results were obtained with the Corynebacterium sp. growing in media containing p-nitrophenol or phenol and in solutions with a purified phosphate salt. The extent of growth of the Corynebacterium sp. wasmore » reduced with 2 or 10 mM phosphate in media containing high Fe concentrations. Ca at 5 mM but not 0.5 mM inhibited p-nitrophenol mineralization by the Corynebacterium sp. with phosphate concentrations from 0.2 to 5.0 mM. Phenol mineralization by the Pseudomonas sp. in medium with 0.2 mM phosphate was rapid at pH 5.2, but the bacteria had little or no activity at pH 8.0. In contrast, the activity was greater at pH 8.0 than at pH 5.2 when the culture contained 10 mM phosphate. These effects of pH were similar in media with 5 mM Ca or no added Ca. The authors conclude that the effect of P on bacterial degradation can be influenced by the pH and the concentrations of Fe and Ca.« less

Antimicrobial activity screening of marine bacteria isolated from Port Klang and Port Tanjung Pelepas

NASA Astrophysics Data System (ADS)

Ibrahim, Nik Nuraznida Nik; Usup, Gires; Ahmad, Asmat

2018-04-01

Over the past ten years, marine natural product researchers have expanded the scope of their studies from macroorganisms such as algae to marine microorganisms. The marine environment is believed to be able to provide novel lead against pathogenic microbes that are evolving and developing resistance to existing pharmaceutical agents. In this study, a total of 150 bacterial isolates isolated from Port Klang and Port Tanjung Pelepas were screened for antimicrobial activity against Staphylococcus aureus, Escherichia coli, Vibrio parahaemolyticus, Entrococcus, faecalis, Pseudomonas aeruginosa and Methicillin-Resistance Staphylococcus aureus (MRSA). Only 10 isolates: PW01, PW02, PB03, and PS (04, 05, 06, 07, 08, 09, and 10) showed strong antibacterial activity. Based on the strongest activity, isolates PW01 and PW02 were selected for secondary screening using well diffusion assay. The dichloromethane extract of Pseudomonas sp. PW01 showed activity against S. aureus (15±0 mm), V. parahaemolyticus (25±1.63 mm) and MRSA (18±0.81 mm). Meanwhile, the diethyl ether extract of Pseudomonas sp. PW02 showed active activity against S. aureus (10±0 mm), V. parahaemolyticus (30±0.94 mm), MRSA (30±0.94 mm), E. coli (22±1.25 mm) and E. faecalis (26±0 mm). Through this study, it was suggested that marine microorganisms may represent an untapped reservoir of biodiversity capable of synthesizing antimicrobial molecules.

Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

PubMed

Saikia, Ratul; Srivastava, Alok K; Singh, Kiran; Arora, Dilip K; Lee, Min-Woong

2005-03-01

Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe(3+) EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability.

Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

PubMed Central

Saikia, Ratul; Srivastava, Alok K.; Singh, Kiran; Lee, Min-Woong

2005-01-01

Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe3+ EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability. PMID:24049472

Microbial diversity in firework chemical exposed soil and water samples collected in Virudhunagar district, Tamil Nadu, India.

PubMed

Dhasarathan, P; Theriappan, P; Ashokraja, C

2010-03-01

Microbial diversity of soil and water samples collected from pyrochemicals exposed areas of Virdhunagar district (Tamil Nadu, India) was studied. Soil and water samples from cultivable area, waste land and city area of the same region were also studied for a comparative acount. There is a remarkable reduction in total heterotrophic bacterial population (THB) in pyrochemicals exposed soil and water samples (42 × 10(4) CFU/g and 5.6 × 10(4) CFU/ml respectively), compared to the THB of cultivable area soil and water samples (98 × 10(7) CFU/g and 38.6 × 10(7) CFU/ml). The generic composition the THB of the pyrochemicals exposed samples too exhibited considerable change compared to other samples. Pseudomonas sp. was the predominant one (41.6%) followed by Achromobacter sp. (25%) in pyrochemical exposed soil and Pseudomonas sp. was the predominant one (25%) in pyrochemical exposed water samples followed by Bacillus sp. (25%) and Micrococcus sp. (16.6%). It was observed that Cornybacterium sp. and Micrococcus sp. were absent completely in pyrochemical exposed soil and Achromobacter sp. was missing in the pyrochemical exposed water samples, which were present in the other samples. The outcome of this study clearly demonstrates that pollutants such as chemicals used in pyrotechniques affect the microbial biodiversity and suitable measures have to be taken to control the pollution level and to save biodiversity.

Balancing Dynamic Strength of Spur Gears Operated at Extended Center Distance

NASA Technical Reports Server (NTRS)

Lin, Hsiang Hsi; Liou, Chuen-Huei; Oswald, Fred B.; Townsend, Dennis P.

1996-01-01

This paper presents an analytical study on using hob offset to balance the dynamic tooth strength of spur gears operated at a center distance greater than the standard value. This study is an extension of a static study by Mabie and others. The study was limited to the offset values that assure the pinion and gear teeth will neither be undercut nor become pointed. The analysis presented in this paper was performed using DANST-PC, a new version of the NASA gear dynamics code. The operating speed of the transmission influences the amount of hob offset required to equalize the dynamic stresses in the pinion and gear. The optimum hob offset for the pinion was found to vary within a small range as the speed changes. The optimum value is generally greater than the optimum value found by static procedures. For gears that must operate over a wide range of speeds, an average offset value may be used.

cis-Chlorobenzene Dihydrodiol Dehydrogenase (TcbB) from Pseudomonas sp. Strain P51, Expressed in Escherichia coli DH5α(pTCB149), Catalyzes Enantioselective Dehydrogenase Reactions

PubMed Central

Raschke, Henning; Fleischmann, Thomas; Van Der Meer, Jan Roelof; Kohler, Hans-Peter E.

1999-01-01

cis-Chlorobenzene dihydrodiol dehydrogenase (CDD) from Pseudomonas sp. strain P51, cloned into Escherichia coli DH5α(pTCB149) was able to oxidize cis-dihydrodihydroxy derivatives (cis-dihydrodiols) of dihydronaphthalene, indene, and four para-substituted toluenes to the corresponding catechols. During the incubation of a nonracemic mixture of cis-1,2-indandiol, only the (+)-cis-(1R,2S) enantiomer was oxidized; the (−)-cis-(S,2R) enantiomer remained unchanged. CDD oxidized both enantiomers of cis-1,2-dihydroxy-1,2,3,4-tetrahydronaphthalene, but oxidation of the (+)-cis-(1S,2R) enantiomer was delayed until the (−)-cis-(1R,2S) enantiomer was completely depleted. When incubated with nonracemic mixtures of para-substituted cis-toluene dihydrodiols, CDD always oxidized the major enantiomer at a higher rate than the minor enantiomer. When incubated with racemic 1-indanol, CDD enantioselectively transformed the (+)-(1S) enantiomer to 1-indanone. This stereoselective transformation shows that CDD also acted as an alcohol dehydrogenase. Additionally, CDD was able to oxidize (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene, (+)-cis-monochlorobiphenyl dihydrodiols, and (+)-cis-toluene dihydrodiol to the corresponding catechols. PMID:10583971

Insights into metabolism and sodium chloride adaptability of carbaryl degrading halotolerant Pseudomonas sp. strain C7.

PubMed

Trivedi, Vikas D; Bharadwaj, Anahita; Varunjikar, Madhushri S; Singha, Arminder K; Upadhyay, Priya; Gautam, Kamini; Phale, Prashant S

2017-08-01

Pseudomonas sp. strain C7 isolated from sediment of Thane creek near Mumbai, India, showed the ability to grow on glucose and carbaryl in the presence of 7.5 and 3.5% of NaCl, respectively. It also showed good growth in the absence of NaCl indicating the strain to be halotolerant. Increasing salt concentration impacted the growth on carbaryl; however, the specific activity of various enzymes involved in the metabolism remained unaffected. Among various enzymes, 1-naphthol 2-hydroxylase was found to be sensitive to chloride as compared to carbaryl hydrolase and gentisate 1,2-dioxygenase. The intracellular concentration of Cl - ions remained constant (6-8 mM) for cells grown on carbaryl either in the presence or absence of NaCl. Thus the ability to adapt to the increasing concentration of NaCl is probably by employing chloride efflux pump and/or increase in the concentration of osmolytes as mechanism for halotolerance. The halotolerant nature of the strain will be beneficial to remediate carbaryl from saline agriculture fields, ecosystems and wastewaters.

Temperature-Dependent Expression of phzM and Its Regulatory Genes lasI and ptsP in Rhizosphere Isolate Pseudomonas sp. Strain M18▿

PubMed Central

Huang, Jiaofang; Xu, Yuquan; Zhang, Hongyan; Li, Yaqian; Huang, Xianqing; Ren, Bin; Zhang, Xuehong

2009-01-01

Pseudomonas sp. strain M18, an effective biological control agent isolated from the melon rhizosphere, has a genetic background similar to that of the opportunistic human pathogen Pseudomonas aeruginosa PAO1. However, the predominant phenazine produced by strain M18 is phenazine-1-carboxylic acid (PCA) rather than pyocyanin (PYO); the quantitative ratio of PCA to PYO is 105 to 1 at 28°C in strain M18, while the ratio is 1 to 2 at 37°C in strain PAO1. We first provided evidence that the differential production of the two phenazines in strains M18 and PAO1 is related to the temperature-dependent and strain-specific expression patterns of phzM, a gene involved in the conversion of PCA to PYO. Transcriptional levels of phzM were measured by quantitative real-time PCR, and the activities of both transcriptional and translational phzM′-′lacZ fusions were determined in strains M18 and PAO1, respectively. Using lasI::Gm and ptsP::Gm inactivation M18 mutants, we further show that expression of the phzM gene is positively regulated by the quorum-sensing protein LasI and negatively regulated by the phosphoenolpyruvate phosphotransferase protein PtsP. Surprisingly, the lasI and ptsP regulatory genes were also expressed in a temperature-dependent and strain-specific manner. The differential production of the phenazines PCA and PYO by strains M18 and PAO1 may be a consequence of selective pressure imposed on P. aeruginosa PAO1 and its relative M18 in the two different niches over a long evolutionary process. PMID:19717631

Degradation of Chloronitrobenzenes by a Coculture of Pseudomonas putida and a Rhodococcus sp.

PubMed Central

Park, Hee-Sung; Lim, Sung-Jin; Chang, Young Keun; Livingston, Andrew G.; Kim, Hak-Sung

1999-01-01

A single microorganism able to mineralize chloronitrobenzenes (CNBs) has not been reported, and degradation of CNBs by coculture of two microbial strains was attempted. Pseudomonas putida HS12 was first isolated by analogue enrichment culture using nitrobenzene (NB) as the substrate, and this strain was observed to possess a partial reductive pathway for the degradation of NB. From high-performance liquid chromatography-mass spectrometry and 1H nuclear magnetic resonance analyses, NB-grown cells of P. putida HS12 were found to convert 3- and 4-CNBs to the corresponding 5- and 4-chloro-2-hydroxyacetanilides, respectively, by partial reduction and subsequent acetylation. For the degradation of CNBs, Rhodococcus sp. strain HS51, which degrades 4- and 5-chloro-2-hydroxyacetanilides, was isolated and combined with P. putida HS12 to give a coculture. This coculture was confirmed to mineralize 3- and 4-CNBs in the presence of an additional carbon source. A degradation pathway for 3- and 4-CNBs by the two isolated strains was also proposed. PMID:10049867

Draft Genome Sequence of Pedobacter sp. Strain V48, Isolated from a Coastal Sand Dune in the Netherlands

PubMed Central

Bitzer, Adam S.; Garbeva, Paolina

2014-01-01

Pedobacter sp. strain V48 participates in an interaction with Pseudomonas fluorescens which elicits interaction-induced phenotypes. We report the draft genome sequence of Pedobacter sp. V48, consisting of 6.46 Mbp. The sequence will contribute to improved understanding of the genus and facilitate genomic analysis of the model interspecies interaction with P. fluorescens. PMID:24578271

Effect of Pseudomonas sp. HF-1 inoculum on construction of a bioaugmented system for tobacco wastewater treatment: analysis from quorum sensing.

PubMed

Wang, Mei-Zhen; He, Hong-Zhen; Zheng, Xin; Feng, Hua-Jun; Lv, Zhen-Mei; Shen, Dong-Sheng

2014-01-01

To better construct a bioaugmented system for tobacco wastewater treatment, activated sludge was inoculated with different concentrations of the nicotine-degrading bacterium Pseudomonas sp. HF-1. The results showed that inoculum concentrations of 0.55 ± 0.01 and 1.10 ± 0.03 mg/g (dry weight of strain HF-1/dry weight of activated sludge) were best to ensure strain HF-1 survival and successful bioaugmentation. The release pattern of autoinducer (AI) for quorum sensing in the bioaugmented system was also investigated. During the period of HF-1 inoculation, compared with failed bioaugmented systems, AI-2 was significantly increased in the successful systems, suggesting that AI-2-mediated bacterial communication played an important role in the colonization of HF-1. When inoculation of strain HF-1 was stopped, the amount of AI-2 decreased and leveled out in all systems. Notably, there was a greater than threefold increase of short-chain AHLs in failed bioaugmented systems, but no increase in successful ones, implying that the fluctuation of short-chain AHLs could be an indicator of the failure of bioaugmentation. Thus, AI-2-mediated quorum sensing could be implemented to facilitate HF-1 colonization.

Degradation capacities of bacteria and yeasts isolated from the gut of Dendroctonus rhizophagus (Curculionidae: Scolytinae).

PubMed

Briones-Roblero, Carlos I; Rodríguez-Díaz, Roberto; Santiago-Cruz, José A; Zúñiga, Gerardo; Rivera-Orduña, Flor N

2017-01-01

Bark beetles (Curculionidae: Scolytinae) feed on the xylem and phloem of their host, which are composed of structural carbohydrates and organic compounds that are not easily degraded by the insects. Some of these compounds might be hydrolyzed by digestive enzymes produced by microbes present in the gut of these insects. In this study, we evaluated the enzymatic capacity of bacteria (Acinetobacter lwoffii, Arthrobacter sp., Pseudomonas putida, Pseudomonas azotoformans, and Rahnella sp.) and yeasts (Candida piceae, Candida oregonensis, Cyberlindnera americana, Zygoascus sp., and Rhodotorula mucilaginosa) isolated from the Dendroctonus rhizophagus gut to hydrolyze cellulose, xylan, pectin, starch, lipids, and esters. All isolates, with the exception of C. piceae, showed lipolytic activity. Furthermore, P. putida, P. azotoformans, C. americana, C. piceae, and R. mucilaginosa presented amylolytic activity. Esterase activity was shown by A. lwoffii, P. azotoformans, and Rahnella sp. Cellulolytic and xylanolytic activities were present only in Arthrobacter sp. and P. azotoformans. The pectinolytic activity was not recorded in any isolate. This is the first study to provide evidence on the capacity of microbes associated with the D. rhizophagus gut to hydrolyze specific substrates, which might cover part of the nutritional requirements for the development, fitness, and survival of these insects.

Nitrogen-fixing bacteria with multiple plant growth-promoting activities enhance growth of tomato and red pepper.

PubMed

Islam, Md Rashedul; Sultana, Tahera; Joe, M Melvin; Yim, Woojong; Cho, Jang-Cheon; Sa, Tongmin

2013-12-01

As a suitable alternative to chemical fertilizers, the application of plant growth-promoting rhizobacteria has been increasing in recent years due to their potential to be used as biofertilizers. In the present work, 13 nitrogen-fixing bacterial strains belonging to 11 different genera were tested for their PGP attributes. All of the strains were positive for 1-aminocyclopropane-1-carboxylate deaminase (ACCD), indole-3-acetic acid (IAA), salicylic acid, and ammonia production while negative for cellulase, pectinase, and hydrocyanic acid production. The strains Pseudomonas sp. RFNB3 and Serratia sp. RFNB14 were the most effective in solubilizing both tri-calcium phosphate and zinc oxide. In addition, all strains except Pseudomonas sp. RFNB3 were able to oxidize sulfur, and six strains were positive for siderophore synthesis. Each strain tested in this study possesses at least four PGP properties in addition to nitrogen fixation. Nine strains were selected based on their multiple PGP potential, particularly ACCD and IAA production, and evaluated for their effects on early growth of tomato and red pepper under gnotobiotic conditions. Bacterial inoculation considerably influenced root and shoot length, seedling vigor, and dry biomass of the two crop plants. Three strains that demonstrated substantial effects on plant performance were further selected for greenhouse trials with red pepper, and among them Pseudomonas sp. RFNB3 resulted in significantly higher plant height (26%) and dry biomass (28%) compared to control. The highest rate of nitrogen fixation, as determined by acetylene reduction assay, occurred in Novosphingobium sp. RFNB21 inoculated red pepper root (49.6 nM of ethylene/h/g of dry root) and rhizosphere soil (41.3 nM of ethylene/h/g of dry soil). Inoculation with nitrogen-fixing bacteria significantly increased chlorophyll content, and the uptake of different macro- and micro-nutrient contents enhancing also in red pepper shoots, in comparison with uninoculated controls. The population estimation studies showed that nitrogen-fixing as well as total heterotrophic bacteria were also noticeably increased in soil and plant samples. The findings of this study suggest that certain nitrogen-fixing strains possessing multiple PGP traits could be applied in the development of biofertilizers. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Testing the accuracy of a 1-D volcanic plume model in estimating mass eruption rate

USGS Publications Warehouse

Mastin, Larry G.

2014-01-01

During volcanic eruptions, empirical relationships are used to estimate mass eruption rate from plume height. Although simple, such relationships can be inaccurate and can underestimate rates in windy conditions. One-dimensional plume models can incorporate atmospheric conditions and give potentially more accurate estimates. Here I present a 1-D model for plumes in crosswind and simulate 25 historical eruptions where plume height Hobs was well observed and mass eruption rate Mobs could be calculated from mapped deposit mass and observed duration. The simulations considered wind, temperature, and phase changes of water. Atmospheric conditions were obtained from the National Center for Atmospheric Research Reanalysis 2.5° model. Simulations calculate the minimum, maximum, and average values (Mmin, Mmax, and Mavg) that fit the plume height. Eruption rates were also estimated from the empirical formula Mempir = 140Hobs4.14 (Mempir is in kilogram per second, Hobs is in kilometer). For these eruptions, the standard error of the residual in log space is about 0.53 for Mavg and 0.50 for Mempir. Thus, for this data set, the model is slightly less accurate at predicting Mobs than the empirical curve. The inability of this model to improve eruption rate estimates may lie in the limited accuracy of even well-observed plume heights, inaccurate model formulation, or the fact that most eruptions examined were not highly influenced by wind. For the low, wind-blown plume of 14–18 April 2010 at Eyjafjallajökull, where an accurate plume height time series is available, modeled rates do agree better with Mobs than Mempir.

Bioremediation of storage tank bottom sludge by using a two-stage composting system: Effect of mixing ratio and nutrients addition.

PubMed

Koolivand, Ali; Rajaei, Mohammad Sadegh; Ghanadzadeh, Mohammad Javad; Saeedi, Reza; Abtahi, Hamid; Godini, Kazem

2017-07-01

The effect of mixing ratio and nutrients addition on the efficiency of a two-stage composting system in removal of total petroleum hydrocarbons (TPH) from storage tank bottom sludge (STBS) was investigated. The system consisted of ten windrow piles as primary composting (PC) followed by four in-vessel reactors as secondary composting (SC). Various initial C/N/P and mixing ratios of STBS to immature compost (IC) were examined in the PC and SC for 12 and 6weeks, respectively. The removal rates of TPH in the two-stage system (93.72-95.24%) were higher than those in the single-stage one. Depending on the experiments, TPH biodegradation fitted to the first- and second-order kinetics with the rate constants of 0.051-0.334d -1 and 0.002-0.165gkg -1 d -1 , respectively. The bacteria identified were Pseudomonas sp., Bacillus sp., Klebsiella sp., Staphylococcus sp., and Proteus sp. The study verified that a two-stage composting system is effective in treating the STBS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficiency in hydrocarbon degradation and biosurfactant production by Joostella sp. A8 when grown in pure culture and consortia.

PubMed

Rizzo, Carmen; Rappazzo, Alessandro Ciro; Michaud, Luigi; De Domenico, Emilio; Rochera, Carlos; Camacho, Antonio; Lo Giudice, Angelina

2018-05-01

Joostella strains are emerging candidates for biosurfactant production. Here such ability was analyzed for Joostella strain A8 in comparison with Alcanivorax strain A53 and Pseudomonas strain A6, all previously isolated from hydrocarbon enrichment cultures made of polychaete homogenates. In pure cultures Joostella sp. A8 showed the highest stable emulsion percentage (78.33%), hydrophobicity rate (62.67%), and an optimal surface tension reduction during growth in mineral medium supplemented with diesel oil (reduction of about 12mN/m), thus proving to be highly competitive with Alcanivorax and Pseudomonas strains. During growth in pure culture different level of biodegradation were detected for Alcanivorax strain A53 (52.7%), Pseudomonas strain A6 (38.2%) and Joostella strain A8 (26.8%). When growing in consortia, isolates achieved similar abundance values, with the best efficiency that was observed for the Joostella-Pseudomonas co-culture. Gas-chromatographic analysis revealed an increase in the biodegradation efficiency in co-cultures (about 90%), suggesting that the contemporary action of different bacterial species could improve the process. Results were useful to compare the efficiencies of well-known biosurfactant producers (i.e. Pseudomonas and Alcanivorax representatives) with a still unknown biosurfactant producer, i.e. Joostella, and to confirm them as optimal biosurfactant-producing candidates. Copyright © 2017. Published by Elsevier B.V.

AiiA, an enzyme that inactivates the acylhomoserine lactone quorum-sensing signal and attenuates the virulence of Erwinia carotovora

PubMed Central

Dong, Yi-Hu; Xu, Jin-Ling; Li, Xian-Zhen; Zhang, Lian-Hui

2000-01-01

N-acylhomoserine lactones, known as autoinducers (AIs), are widely conserved signal molecules present in quorum-sensing systems of many Gram-negative bacteria. AIs are involved in the regulation of diverse biological functions, including expression of pathogenic genes in the plant pathogens Pseudomonas solanacearum, several Erwinia species, and the human pathogen Pseudomonas aeruginosa. A bacterial isolate, Bacillus sp. 240B1, is capable of enzymatic inactivation of AIs. The gene (aiiA) for AI inactivation from Bacillus sp. 240B1 has been cloned and shown to encode a protein of 250 amino acids. Sequence alignment indicates that AiiA contains a “HXHXDH” zinc-binding motif that is conserved in several groups of metallohydrolases. Site-directed mutagenesis showed that conserved aspartate and most histidine residues are required for AiiA activity. Expression of aiiA in transformed Erwinia carotovora strain SCG1 significantly reduces the release of AI, decreases extracellular pectolytic enzyme activities, and attenuates pathogenicity on potato, eggplant, Chinese cabbage, carrot, celery, cauliflower, and tobacco. Our results indicate that the AI-inactivation approach represents a promising strategy for prevention of diseases in which virulence is regulated by AIs. PMID:10716724

Structural adaptation of cold-active RTX lipase from Pseudomonas sp. strain AMS8 revealed via homology and molecular dynamics simulation approaches.

PubMed

Mohamad Ali, Mohd Shukuri; Mohd Fuzi, Siti Farhanie; Ganasen, Menega; Abdul Rahman, Raja Noor Zaliha Raja; Basri, Mahiran; Salleh, Abu Bakar

2013-01-01

The psychrophilic enzyme is an interesting subject to study due to its special ability to adapt to extreme temperatures, unlike typical enzymes. Utilizing computer-aided software, the predicted structure and function of the enzyme lipase AMS8 (LipAMS8) (isolated from the psychrophilic Pseudomonas sp., obtained from the Antarctic soil) are studied. The enzyme shows significant sequence similarities with lipases from Pseudomonas sp. MIS38 and Serratia marcescens. These similarities aid in the prediction of the 3D molecular structure of the enzyme. In this study, 12 ns MD simulation is performed at different temperatures for structural flexibility and stability analysis. The results show that the enzyme is most stable at 0°C and 5°C. In terms of stability and flexibility, the catalytic domain (N-terminus) maintained its stability more than the noncatalytic domain (C-terminus), but the non-catalytic domain showed higher flexibility than the catalytic domain. The analysis of the structure and function of LipAMS8 provides new insights into the structural adaptation of this protein at low temperatures. The information obtained could be a useful tool for low temperature industrial applications and molecular engineering purposes, in the near future.

The Military Efficacy of Individual Water Purification Filters.

DTIC Science & Technology

1990-12-01

criteria. ’t *.;as a.Lso serv ea that the KPF units grew opportunistic Pseudomonas sp . on the oroduct water side of the filters, which could have a...small pathogenic protozoan cysts such as Cryptospor-dium parvum, Giardia lamblia, and Entamoeba coli, from water over the effective use life of the...of heterotrophic bacteria such as Pseudoronas sP , Flavobacterium Sp , and other potentially harmfui organisms inside of the units. Enteric viruses are

The Tale of a Neglected Energy Source: Elevated Hydrogen Exposure Affects both Microbial Diversity and Function in Soil

DOE PAGES

Khdhiri, Mondher; Piché-Choquette, Sarah; Tremblay, Julien; ...

2017-03-31

The enrichment of H 2-oxidizing bacteria (HOB) by H 2 generated by nitrogen-fixing nodules has been shown to have a fertilization effect on several different crops. The benefit of HOB is attributed to their production of plant growth-promoting factors, yet their interactions with other members of soil microbial communities have received little attention. In this paper, we report that the energy potential of H 2, when supplied to soil, alters ecological niche partitioning of bacteria and fungi, with multifaceted consequences for both generalist and specialist microbial functions. We used dynamic microcosms to expose soil to the typical atmospheric H 2more » mixing ratio (0.5 ppmv) permeating soils, as well as mixing ratios comparable to those found at the soil-nodule interface (10,000 ppmv). Elevated H 2 exposure exerted direct effects on two HOB subpopulations distinguished by their affinity for H 2 while enhancing community level carbon substrate utilization potential and lowering CH 4 uptake activity in soil. We found that H 2 triggered changes in the abundance of microorganisms that were reproducible yet inconsistent across soils at the taxonomic level and even among HOB. Overall, H 2 exposure altered microbial process rates at an intensity that depends upon soil abiotic and biotic features. Finally, we argue that further examination of direct and indirect effects of H 2 on soil microbial communities will lead to a better understanding of the H 2 fertilization effect and soil biogeochemical processes.« less

The Tale of a Neglected Energy Source: Elevated Hydrogen Exposure Affects both Microbial Diversity and Function in Soil

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

Khdhiri, Mondher; Piché-Choquette, Sarah; Tremblay, Julien

The enrichment of H 2-oxidizing bacteria (HOB) by H 2 generated by nitrogen-fixing nodules has been shown to have a fertilization effect on several different crops. The benefit of HOB is attributed to their production of plant growth-promoting factors, yet their interactions with other members of soil microbial communities have received little attention. In this paper, we report that the energy potential of H 2, when supplied to soil, alters ecological niche partitioning of bacteria and fungi, with multifaceted consequences for both generalist and specialist microbial functions. We used dynamic microcosms to expose soil to the typical atmospheric H 2more » mixing ratio (0.5 ppmv) permeating soils, as well as mixing ratios comparable to those found at the soil-nodule interface (10,000 ppmv). Elevated H 2 exposure exerted direct effects on two HOB subpopulations distinguished by their affinity for H 2 while enhancing community level carbon substrate utilization potential and lowering CH 4 uptake activity in soil. We found that H 2 triggered changes in the abundance of microorganisms that were reproducible yet inconsistent across soils at the taxonomic level and even among HOB. Overall, H 2 exposure altered microbial process rates at an intensity that depends upon soil abiotic and biotic features. Finally, we argue that further examination of direct and indirect effects of H 2 on soil microbial communities will lead to a better understanding of the H 2 fertilization effect and soil biogeochemical processes.« less

Evidence for a novel pathway in the degradation of fluorene by Pseudomonas sp. strain F274.

PubMed Central

Grifoll, M; Selifonov, S A; Chapman, P J

1994-01-01

A fluorene-utilizing microorganism, identified as a species of Pseudomonas, was isolated from soil severely contaminated from creosote use and was shown to accumulate six major metabolites from fluorene in washed-cell incubations. Five of these products were identified as 9-fluorenol, 9-fluorenone, (+)-1,1a-dihydroxy-1-hydro-9-fluorenone, 8-hydroxy-3,4-benzocoumarin, and phthalic acid. This last compound was also identified in growing cultures supported by fluorene. Fluorene assimilation into cell biomass was estimated to be approximately 50%. The structures of accumulated products indicate that a previously undescribed pathway of fluorene catabolism is employed by Pseudomonas sp. strain F274. This pathway involves oxygenation of fluorene at C-9 to give 9-fluorenol, which is then dehydrogenated to the corresponding ketone, 9-fluorenone. Dioxygenase attack on 9-fluorenone adjacent to the carbonyl group gives an angular diol, 1,1a-dihydroxy-1-hydro-9-fluorenone. Identification of 8-hydroxy-3,4-benzocoumarin and phthalic acid suggests that the five-membered ring of the angular diol is opened first and that the resulting 2'-carboxy derivative of 2,3-dihydroxy-biphenyl is catabolized by reactions analogous to those of biphenyl degradation, leading to the formation of phthalic acid. Cell extracts of fluorene-grown cells possessed high levels of an enzyme characteristic of phthalate catabolism, 4,5-dihydroxyphthalate decarboxylase, together with protocatechuate 4,5-dioxygenase. On the basis of these findings, a pathway of fluorene degradation is proposed to account for its conversion to intermediary metabolites. A range of compounds with structures similar to that of fluorene was acted on by fluorene-grown cells to give products consistent with the initial reactions proposed. PMID:8074523

Isolation, Cloning and Expression of the Genes for Microbial Polyurethane Degradation

DTIC Science & Technology

1991-02-20

Aspergillus niger --fungi ATCC 12668 Trichoderma sp.--fungi The minimal salts medium is as follows: 72 Minimal (NH4) 2s O 4 1.000 gm/L KH2PO4 5.000 gm/L MGSO 4...culture ATCC 35698 Arthobacter globiformis--bacteria ATCC 11172 Pseudomonas putida--bacteria ATCC 10196 Aspergillus oryzae--fungi ATCC 9642

Deterioration to extinction of wastewater bacteria by non-thermal atmospheric pressure air plasma as assessed by 16S rDNA-DGGE fingerprinting

PubMed Central

El-Sayed, Wael S.; Ouf, Salama A.; Mohamed, Abdel-Aleam H.

2015-01-01

The use of cold plasma jets for inactivation of a variety of microorganisms has recently been evaluated via culture-based methods. Accordingly, elucidation of the role of cold plasma in decontamination would be inaccurate because most microbial populations within a system remain unexplored owing to the high amount of yet uncultured bacteria. The impact of cold atmospheric plasma on the bacterial community structure of wastewater from two different industries was investigated by metagenomic-based polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) utilizing 16S rRNA genes. Three doses of atmospheric pressure dielectric barrier discharge plasma were applied to wastewater samples on different time scales. DGGE revealed that the bacterial community gradually changed and overall abundance decreased to extinction upon plasma treatment. The bacterial community in food processing wastewater contained 11 key operational taxonomic units that remained almost completely unchanged when exposed to plasma irradiation at 75.5 mA for 30 or 60 s. However, when exposure time was extended to 90 s, only Escherichia coli, Coliforms, Aeromonas sp., Vibrio sp., and Pseudomonas putida survived. Only E. coli, Aeromonas sp., Vibrio sp., and P. putida survived treatment at 81.94 mA for 90 s. Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90 s. Dominant bacterial groups in leather processing wastewater also changed greatly upon exposure to plasma at 75.5 mA for 30 or 60 s, with Enterobacter aerogenes, Klebsiella sp., Pseudomonas stutzeri, and Acidithiobacillus ferrooxidans being sensitive to and eliminated from the community. At 90 s of exposure, all groups were affected except for Pseudomonas sp. and Citrobacter freundii. The same trend was observed for treatment at 81.94 mA. The variability in bacterial community response to different plasma treatment protocols revealed that plasma had a selective impact on bacterial community structure at lower doses and potential bactericidal effects at higher doses. PMID:26500637

Origin of Coverage Dependence in Photoreactivity of Carboxylate on TiO2(110): Hindering by Charged Coadsorbed Hydroxyls

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

Wang, Zhitao; Henderson, Michael A.; Lyubinetsky, Igor

2015-09-30

The influence of reactant coverage on photochemical activity was explored using scanning tunneling microscopy (STM) and ultraviolet photoelectron spectroscopy (UPS). We observed diminished reactivity of carboxylate species (trimethyl acetate, TMA) on TiO2(110) as a function of increasing coverage. This effect was not linked to intermolecular interactions of TMA but to the accumulation of the coadsorbed bridging hydroxyls (HOb) deposited during (thermal) dissociative adsorption of the parent, trimethylacetic acid (TMAA). Confirmation of the hindering influence of HOb groups was obtained by the observation that HOb species originated from H2O dissociation at O-vacancy sites have a similar hindering effect on TMA photochemistry.more » Though HOb’s are photoinactive on TiO2(110) under ultrahigh vacuum conditions, UPS results show that these sites trap photoexcited electrons, which in turn likely (electrostatically) attract and neutralize photoexcited holes, thus suppressing the hole-mediated photoreactivity of TMA. This negative influence of surface hydroxyls on hole-mediated photochemistry is likely a major factor in other anaerobic photochemical processes on reducible oxide surfaces.« less

Glyphosate catabolism by Pseudomonas sp

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

Shinabarger, D.L.

1986-01-01

The pathway for the degradation of glyphosate (N-phosphonomethylglycine) by Pseudomonas sp. PG2982 has been determined using metabolic radiolabeling experiments. Radiorespirometry experiments utilizing (3-/sup 14/C) glyphosate revealed that approximately 50-59% of the C3 carbon was oxidized to CO/sub 2/. Fractionation of stationary phase cells labeled with (3-/sup 14/C)glyphosate revealed that from 45-47% of the assimilated C3 carbon is distributed to proteins and that amino acids methionine and serine are highly labeled. The nucleic acid bases adenine and guanine received 90% of the C3 label that was incorporated into nucleic acids, and the only pyrimidine base labeled was thymine. Pulse labeling ofmore » PG2982 cells with (3-/sup 14/C)glyphosate revealed that (3-/sup 14/C)sarcosine is an intermediate in glyphosate degradation. Examination of crude extracts prepared from PG2982 cells revealed the presence of an enzyme that oxidizes sarcosine to glycine and formaldehyde. These results indicate that the first step in glyphosate degradation by PG2982 is cleavage of the carbon-phosphorus bond, resulting in the release of sarcosine and a phosphate group. The phosphate group is utilized as a source of phosphorus, and the sarcosine is degraded to glycine and formaldehyde. Phosphonate utilization by Pseudomonas sp. PG2982 was investigated. Each of the ten phosphonates tested were utilized as a sole source of phosphorus by PG2982. Representative compounds tested included alkylphosphonates, 1-amino-substituted alkylphosphonates, amino-terminal phosphonates, and an arylphosphonate. PG2982 cultures degraded phenylphosphonate to benzene and produced methane from methylphosphonate. The data indicate that PG2982 is capable of cleaving the carbon-phosphorus bond of several structurally different phosphonates.« less

Characterization of Pb2+ biosorption by psychrotrophic strain Pseudomonas sp. I3 isolated from permafrost soil of Mohe wetland in Northeast China.

PubMed

Li, Dandan; Xu, Xingjian; Yu, Hongwen; Han, Xuerong

2017-07-01

Due to the long and severe winter in Northeast China, wastewater containing lead (Pb) is treated inefficiently, resulting in irregular disposal. In order to solve this problem, a Pb-resistant psychrotrophic bacterium, Pseudomonas sp. I3, was isolated from permafrost soil of Mohe wetland and served as biosorbent for Pb 2+ removal under 15 °C. The minimum inhibitory concentration of strain I3 for Pb 2+ was 7.5 mM, which was higher than that of Escherichia coli DH5α (1.5 mM). However, acid digestion results showed that these two bacteria had a comparable biosorption capacity for Pb 2+ , suggesting no direct relationship between biosorption ability of bacteria and their metal-resistance. Acid digestion results also proved that intracellular Pb accumulation was mainly contributed to the distinct performance between living and non-living biosorbents, which was further confirmed by the analyses of TEM-EDS. Results of FTIR revealed that functional groups including CH 2 , CO, CN, NH, COO and SO 3 were participated in the biosorption process of the tested biosorbents no matter bacteria were living or not. The effects of environmental factors including pH, temperature, biomass dose, operation time and initial Pb 2+ concentration were investigated through a batch of biosorption experiments. The equilibrium data for living and non-living biosorbent were well fitted to Langmuir model with their maximum Pb 2+ biosorption capacities of 49.48 and 42.37 mg/g, respectively. The kinetic data for each biosorbent were well described by pseudo-second order kinetic model. Overall, Pseudomonas sp. I3 seemed to be an effective biosorbent for cleansing Pb 2+ from contaminated wastewater at low temperature. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel Phenanthrene-Degrading Bacteria Identified by DNA-Stable Isotope Probing

PubMed Central

Luo, Chunling; Zhang, Dayi; Zhang, Gan

2015-01-01

Microorganisms responsible for the degradation of phenanthrene in a clean forest soil sample were identified by DNA-based stable isotope probing (SIP). The soil was artificially amended with either 12C- or 13C-labeled phenanthrene, and soil DNA was extracted on days 3, 6 and 9. Terminal restriction fragment length polymorphism (TRFLP) results revealed that the fragments of 219- and 241-bp in HaeIII digests were distributed throughout the gradient profile at three different sampling time points, and both fragments were more dominant in the heavy fractions of the samples exposed to the 13C-labeled contaminant. 16S rRNA sequencing of the 13C-enriched fraction suggested that Acidobacterium spp. within the class Acidobacteria, and Collimonas spp. within the class Betaproteobacteria, were directly involved in the uptake and degradation of phenanthrene at different times. To our knowledge, this is the first report that the genus Collimonas has the ability to degrade PAHs. Two PAH-RHDα genes were identified in 13C-labeled DNA. However, isolation of pure cultures indicated that strains of Staphylococcus sp. PHE-3, Pseudomonas sp. PHE-1, and Pseudomonas sp. PHE-2 in the soil had high phenanthrene-degrading ability. This emphasizes the role of a culture-independent method in the functional understanding of microbial communities in situ. PMID:26098417

New α-Pyridones with Quorum-Sensing Inhibitory Activity from Diversity-Enhanced Extracts of a Streptomyces sp. Derived from Marine Algae.

PubMed

Du, Yuqi; Sun, Jian; Gong, Qianhong; Wang, Yi; Fu, Peng; Zhu, Weiming

2018-02-28

Four new α-pyrones (1-4) and eight known analogues (5-12) were identified from the secondary metabolites of Streptomyces sp. OUCMDZ-3436 derived from the marine green algae Enteromorpha prolifera. Seven new α-pyridones (14-20) were constructed by diversity-oriented synthesis, which has been an effective approach to expanding the chemical space of natural-product-like compounds. Compounds 16, 17, 19, and 20 were found to have inhibitory effect on the gene expression controlled by quorum sensing in Pseudomonas aeruginosa QSIS-lasI.

Indole diterpenoids from the endophytic fungus Drechmeria sp. as natural antimicrobial agents.

PubMed

Zhao, Jian-Chao; Wang, Ya-Li; Zhang, Tian-Yuan; Chen, Zhong-Jian; Yang, Tian-Mei; Wu, Ying-Ying; Sun, Cheng-Peng; Ma, Xiao-Chi; Zhang, Yi-Xuan

2018-04-01

A fungal strain, Drechmeria sp., was isolated from the root of Panax notoginseng. Totally, seven new indole diterpenoids, drechmerins A-G (1-7), were isolated from the fermentation broth of Drechmeria sp. together with four known analogues (8-11). Their structures were determined on the basis of 1D and 2D NMR and electronic circular dichroism (ECD) spectroscopic analyses as well as theoretical calculations. All the isolated compounds were evaluated for their antimicrobial activities against Candida albicans, Staphylococcus aureus, Bacillus cereus, B. subtillis, Pseudomonas aeruginosa, and Klebsiella pneumonia, respectively. Drechmerin B (2) displayed antimicrobial activity against C. albicans with an MIC value of 12.5 μg/mL. Molecular docking was used to investigate interactions of peptide deformylase with compounds 1-3, 5-7, 9, and 10. Copyright © 2018 Elsevier Ltd. All rights reserved.

Discovery of Phloeophagus Beetles as a Source of Pseudomonas Strains That Produce Potentially New Bioactive Substances and Description of Pseudomonas bohemica sp. nov.

PubMed

Saati-Santamaría, Zaki; López-Mondéjar, Rubén; Jiménez-Gómez, Alejandro; Díez-Méndez, Alexandra; Větrovský, Tomáš; Igual, José M; Velázquez, Encarna; Kolarik, Miroslav; Rivas, Raúl; García-Fraile, Paula

2018-01-01

Antimicrobial resistance is a worldwide problem that threatens the effectiveness of treatments for microbial infection. Consequently, it is essential to study unexplored niches that can serve for the isolation of new microbial strains able to produce antimicrobial compounds to develop new drugs. Bark beetles live in phloem of host trees and establish symbioses with microorganisms that provide them with nutrients. In addition, some of their associated bacteria play a role in the beetle protection by producing substances that inhibit antagonists. In this study the capacity of several bacterial strains, isolated from the bark beetles Ips acuminatus, Pityophthorus pityographus Cryphalus piceae , and Pityogenes bidentatus , to produce antimicrobial compounds was analyzed. Several isolates exhibited the capacity to inhibit Gram-positive and Gram-negative bacteria, as well as fungi. The genome sequence analysis of three Pseudomonas isolates predicted the presence of several gene clusters implicated in the production of already described antimicrobials and moreover, the low similarity of some of these clusters with those previously described, suggests that they encode new undescribed substances, which may be useful for developing new antimicrobial agents. Moreover, these bacteria appear to have genetic machinery for producing antitumoral and antiviral substances. Finally, the strain IA19 T showed to represent a new species of the genus Pseudomonas . The 16S rRNA gene sequence analysis showed that its most closely related species include Pseudomonas lutea, Pseudomonas graminis, Pseudomonas abietaniphila and Pseudomonas alkylphenolica, with 98.6, 98.5 98.4, and 98.4% identity, respectively. MLSA of the housekeeping genes gyr B, rpo B, and rpo D confirmed that strain IA19 T clearly separates from its closest related species. Average nucleotide identity between strains IA19 T and P. abietaniphila ATCC 700689 T , P. graminis DSM 11363 T , P. alkylphenolica KL28 T and P. lutea DSM 17257 T were 85.3, 80.2, 79.0, and 72.1%, respectively. Growth occurs at 4-37°C and pH 6.5-8. Optimal growth occurs at 28°C, pH 7-8 and up to 2.5% NaCl. Respiratory ubiquinones are Q9 (97%) and Q8 (3%). C16:0 and in summed feature 3 are the main fatty acids. Based on genotypic, phenotypic and chemotaxonomic characteristics, the description of Pseudomonas bohemica sp. nov. has been proposed. The type strain is IA19 T (=CECT 9403 T = LMG 30182 T ).

Endophytic bacterial flora in root and stem tissues of black pepper (Piper nigrum L.) genotype: isolation, identification and evaluation against Phytophthora capsici.

PubMed

Aravind, R; Kumar, A; Eapen, S J; Ramana, K V

2009-01-01

To isolate and identify black pepper (Piper nigrum L) associated endophytic bacteria antagonistic to Phytophthora capsici causing foot rot disease. Endophytic bacteria (74) were isolated, characterized and evaluated against P. capsici. Six genera belong to Pseudomonas spp (20 strains), Serratia (1 strain), Bacillus spp. (22 strains), Arthrobacter spp. (15 strains), Micrococcus spp. (7 strains), Curtobacterium sp. (1 strain) and eight unidentified strains were isolated from internal tissues of root and stem. Three isolates, IISRBP 35, IISRBP 25 and IISRBP 17 were found effective for Phytophthora suppression in multilevel screening assays which recorded over 70% disease suppression in greenhouse trials. A species closest match (99% similarity) of IISRBP 35 was established as Pseudomonas aeruginosa (Pseudomonas EF568931), IISRBP 25 as P. putida (Pseudomonas EF568932), and IISRBP 17 as Bacillus megaterium (B. megaterium EU071712) based on 16S rDNA sequencing. Black pepper associated P. aeruginosa, P. putida and B. megaterium were identified as effective antagonistic endophytes for biological control of Phytophthora foot rot in black pepper. This work provides the first evidence for endophytic bacterial diversity in black pepper stem and roots, with biocontrol potential against P. capsici infection.

Assessing the resistance and bioremediation ability of selected bacterial and protozoan species to heavy metals in metal-rich industrial wastewater

PubMed Central

2013-01-01

Background Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/die-off-rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates. Results The results revealed that the industrial-wastewater samples were highly polluted with heavy-metal concentrations exceeding by far the maximum limits (in mg/l) of 0.05-Co, 0.2-Ni, 0.1-Mn, 0.1-V, 0.01-Pb, 0.01-Cu, 0.1-Zn and 0.005-Cd, prescribed by the UN-FAO. Industrial-wastewater had no major effects on Pseudomonas putida, Bacillus licheniformis and Peranema sp. (growth rates up to 1.81, 1.45 and 1.43 d-1, respectively) compared to other test isolates. This was also revealed with significant COD increases (p < 0.05) in culture media inoculated with living bacterial isolates (over 100%) compared to protozoan isolates (up to 24% increase). Living Pseudomonas putida demonstrated the highest removal rates of heavy metals (Co-71%, Ni-51%, Mn-45%, V-83%, Pb-96%, Ti-100% and Cu-49%) followed by Bacillus licheniformis (Al-23% and Zn-53%) and Peranema sp. (Cd-42%). None of the dead cells were able to remove more than 25% of the heavy metals. Bacterial isolates contained the genes copC, chrB, cnrA3 and nccA encoding the resistance to Cu, Cr, Co-Ni and Cd-Ni-Co, respectively. Protozoan isolates contained only the genes encoding Cu and Cr resistance (copC and chrB genes). Peranema sp. was the only protozoan isolate which had an additional resistant gene cnrA3 encoding Co-Ni resistance. Conclusion Significant differences (p < 0.05) observed between dead and living microbial cells for metal-removal and the presence of certain metal-resistant genes indicated that the selected microbial isolates used both passive (biosorptive) and active (bioaccumulation) mechanisms to remove heavy metals from industrial wastewater. This study advocates the use of Peranema sp. as a potential candidate for the bioremediation of heavy-metals in wastewater treatment, in addition to Pseudomonas putida and Bacillus licheniformis. PMID:23387904

Assessing the resistance and bioremediation ability of selected bacterial and protozoan species to heavy metals in metal-rich industrial wastewater.

PubMed

Kamika, Ilunga; Momba, Maggy N B

2013-02-06

Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/die-off-rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates. The results revealed that the industrial-wastewater samples were highly polluted with heavy-metal concentrations exceeding by far the maximum limits (in mg/l) of 0.05-Co, 0.2-Ni, 0.1-Mn, 0.1-V, 0.01-Pb, 0.01-Cu, 0.1-Zn and 0.005-Cd, prescribed by the UN-FAO. Industrial-wastewater had no major effects on Pseudomonas putida, Bacillus licheniformis and Peranema sp. (growth rates up to 1.81, 1.45 and 1.43 d-1, respectively) compared to other test isolates. This was also revealed with significant COD increases (p < 0.05) in culture media inoculated with living bacterial isolates (over 100%) compared to protozoan isolates (up to 24% increase). Living Pseudomonas putida demonstrated the highest removal rates of heavy metals (Co-71%, Ni-51%, Mn-45%, V-83%, Pb-96%, Ti-100% and Cu-49%) followed by Bacillus licheniformis (Al-23% and Zn-53%) and Peranema sp. (Cd-42%). None of the dead cells were able to remove more than 25% of the heavy metals. Bacterial isolates contained the genes copC, chrB, cnrA3 and nccA encoding the resistance to Cu, Cr, Co-Ni and Cd-Ni-Co, respectively. Protozoan isolates contained only the genes encoding Cu and Cr resistance (copC and chrB genes). Peranema sp. was the only protozoan isolate which had an additional resistant gene cnrA3 encoding Co-Ni resistance. Significant differences (p < 0.05) observed between dead and living microbial cells for metal-removal and the presence of certain metal-resistant genes indicated that the selected microbial isolates used both passive (biosorptive) and active (bioaccumulation) mechanisms to remove heavy metals from industrial wastewater. This study advocates the use of Peranema sp. as a potential candidate for the bioremediation of heavy-metals in wastewater treatment, in addition to Pseudomonas putida and Bacillus licheniformis.

Resistance to Fusarium oxysporum f. sp. gladioli in transgenic Gladiolus plants expressing either a bacterial chloroperoxidase or fungal chitinase genes

USDA-ARS?s Scientific Manuscript database

Three antifungal genes, a non-heme chloroperoxidase from Pseudomonas pyrrocinia, and an exochitinase and endochitinase from Fusarium venetanum under regulation by the CaMV 35S promoter, were used to transform Gladiolus for resistance to Fusarium oxysporum f. sp. gladioli. Gladiolus plants were conf...

The hrpZ Gene of Pseudomonas syringae pv. phaseolicola Enhances Resistance to Rhizomania Disease in Transgenic Nicotiana benthamiana and Sugar Beet

PubMed Central

Pavli, Ourania I.; Kelaidi, Georgia I.; Tampakaki, Anastasia P.; Skaracis, George N.

2011-01-01

To explore possible sources of transgenic resistance to the rhizomania-causing Beet necrotic yellow vein virus (BNYVV), Nicotiana benthamiana plants were constructed to express the harpin of Pseudomonas syringae pv. phaseolicola (HrpZPsph). The HrpZ protein was expressed as an N-terminal fusion to the PR1 signal peptide (SP/HrpZ) to direct harpin accumulation to the plant apoplast. Transgene integration was verified by mPCR in all primary transformants (T0), while immunoblot analysis confirmed that the protein HrpZPsph was produced and the signal peptide was properly processed. Neither T0 plants nor selfed progeny (T1) showed macroscopically visible necrosis or any other macroscopic phenotypes. However, plants expressing the SP/HrpZPsph showed increased vigor and grew faster in comparison with non-transgenic control plants. Transgenic resistance was assessed after challenge inoculation with BNYVV on T1 progeny by scoring of disease symptoms and by DAS-ELISA at 20 and 30 dpi. Transgenic and control lines showed significant differences in terms of the number of plants that became infected, the timing of infection and the disease symptoms displayed. Plants expressing the SP/HrpZPsph developed localized leaf necrosis in the infection area and had enhanced resistance upon challenge with BNYVV. In order to evaluate the SP/HrpZ-based resistance in the sugar beet host, A. rhizogenes-mediated root transformation was exploited as a transgene expression platform. Upon BNYVV inoculation, transgenic sugar beet hairy roots showed high level of BNYVV resistance. In contrast, the aerial non-transgenic parts of the same seedlings had virus titers that were comparable to those of the seedlings that were untransformed or transformed with wild type R1000 cells. These findings indicate that the transgenically expressed SP/HrpZ protein results in enhanced rhizomania resistance both in a model plant and sugar beet, the natural host of BNYVV. Possible molecular mechanisms underlying the enhanced resistance and plant growth phenotypes observed in SP/HrpZ transgenic plants are discussed. PMID:21394206

The hrpZ gene of Pseudomonas syringae pv. phaseolicola enhances resistance to rhizomania disease in transgenic Nicotiana benthamiana and sugar beet.

PubMed

Pavli, Ourania I; Kelaidi, Georgia I; Tampakaki, Anastasia P; Skaracis, George N

2011-03-04

To explore possible sources of transgenic resistance to the rhizomania-causing Beet necrotic yellow vein virus (BNYVV), Nicotiana benthamiana plants were constructed to express the harpin of Pseudomonas syringae pv. phaseolicola (HrpZ(Psph)). The HrpZ protein was expressed as an N-terminal fusion to the PR1 signal peptide (SP/HrpZ) to direct harpin accumulation to the plant apoplast. Transgene integration was verified by mPCR in all primary transformants (T0), while immunoblot analysis confirmed that the protein HrpZ(Psph) was produced and the signal peptide was properly processed. Neither T0 plants nor selfed progeny (T1) showed macroscopically visible necrosis or any other macroscopic phenotypes. However, plants expressing the SP/HrpZ(Psph) showed increased vigor and grew faster in comparison with non-transgenic control plants. Transgenic resistance was assessed after challenge inoculation with BNYVV on T1 progeny by scoring of disease symptoms and by DAS-ELISA at 20 and 30 dpi. Transgenic and control lines showed significant differences in terms of the number of plants that became infected, the timing of infection and the disease symptoms displayed. Plants expressing the SP/HrpZ(Psph) developed localized leaf necrosis in the infection area and had enhanced resistance upon challenge with BNYVV. In order to evaluate the SP/HrpZ-based resistance in the sugar beet host, A. rhizogenes-mediated root transformation was exploited as a transgene expression platform. Upon BNYVV inoculation, transgenic sugar beet hairy roots showed high level of BNYVV resistance. In contrast, the aerial non-transgenic parts of the same seedlings had virus titers that were comparable to those of the seedlings that were untransformed or transformed with wild type R1000 cells. These findings indicate that the transgenically expressed SP/HrpZ protein results in enhanced rhizomania resistance both in a model plant and sugar beet, the natural host of BNYVV. Possible molecular mechanisms underlying the enhanced resistance and plant growth phenotypes observed in SP/HrpZ transgenic plants are discussed.

Reversible reduction of estrone to 17β-estradiol by Rhizobium, Sphingopyxis, and Pseudomonas isolates from the Las Vegas Wash

USGS Publications Warehouse

Blunt, Susanna M.; Benotti, Mark J.; Rosen, Michael R.; Hedlund, Brian; Moser, Duane

2017-01-01

Environmental endocrine-disrupting compounds (EDCs) are a growing concern as studies reveal their persistence and detrimental effects on wildlife. Microorganisms are known to affect the transformation of steroid EDCs; however, the diversity of estrogen-degrading microorganisms and the range of transformations they mediate remain relatively little studied. In mesocosms, low concentrations of added estrone (E1) and 17β-estradiol (E2) were removed by indigenous microorganisms from Las Vegas Wash water within 2 wk. Three bacterial isolates, Rhizobium sp. strain LVW-9, Sphingopyxis sp. strain LVW-12, and Pseudomonas sp. strain LVW-PC, were enriched from Las Vegas Wash water on E1 and E2 and used for EDC transformation studies. In the presence of alternative carbon sources, LVW-9 and LVW-12 catalyzed near-stoichiometric reduction of E1 to E2 but subsequently reoxidized E2 back to E1; whereas LVW-PC minimally reduced E1 to E2 but effectively oxidized E2 to E1 after a 20-d lag. In the absence of alternative carbon sources, LVW-12 and LVW-PC oxidized E2 to E1. This report documents the rapid and sometimes reversible microbial transformation of E1 and E2 and the slow degradation of 17α-ethinylestradiol in urban stream water and extends the list of known estrogen-transforming bacteria to the genera Rhizobium and Sphingopyxis. These results suggest that discharge of steroid estrogens via wastewater could be reduced through tighter control of redox conditions and may assist in future risk assessments detailing the environmental fate of estrogens through evidence that microbial estrogen transformations may be affected by environmental conditions or growth status.

Purification and characterization of chitinases and chitosanases from a new species strain Pseudomonas sp. TKU015 using shrimp shells as a substrate.

PubMed

Wang, San-Lang; Chen, Shin-Jen; Wang, Chuan-Lu

2008-05-19

A chitinase (CHT1) and a chitosanase (CHS1) were purified from the culture supernatant of Pseudomonas sp. TKU015 with shrimp shell wastes as the sole carbon and nitrogen source. The optimized conditions of this new species strain (Gen Bank Accession Number EU103629) for the production of chitinases were found to be when the culture was shaken at 30 degrees C for 3 days in 100 mL of medium (pH 8) containing 0.5% shrimp shell powder (SSP) (w/v), 0.1% K2HPO4, and 0.05% MgSO(4).7H2O. The molecular weights of CHT1 and CHS1 determined by SDS-PAGE were approximately 68 kDa and 30 kDa, respectively. The optimum pH, optimum temperature, pH stability, and the thermal stability of CHT1 and CHS1 were pH 6, 50 degrees C, pH 5-7, <50 degrees C and pH 4, 50 degrees C, pH 3-9, <50 degrees C, respectively. CHT1 was inhibited completely by Mn2+ and Fe2+, and CHS1 was inhibited by Mn2+, Cu2+, and PMSF. CHT1 was only specific to chitin substrates, whereas the relative activity of CHS1 increased when the degree of deacetylation of soluble chitosan increased.

New Developments in Mitigation of Microbiologically Influenced Corrosion

DTIC Science & Technology

2007-07-12

either bacterium. Higher R1, values for surfaces colonized by S . marcescens compared to those colonized by Pseudomonas sp. were attributed to higher...numbers of S . marcescens cells attached to the metal surface. Impedance spectra (see Figure 1) after immersion in sterile and inoculated VNSS demonstrated...NUMBER New Developments in Mitigation of Microbiologically Influenced Corrosion. 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 0601153N 6. AUTHOR( S ) 5d

Enhanced biocatalytic production of L-cysteine by Pseudomonas sp. B-3 with in situ product removal using ion-exchange resin.

PubMed

Wang, Pu; He, Jun-Yao; Yin, Jiang-Feng

2015-03-01

Bioconversion of DL-2-amino-Δ(2)-thiazoline-4-carboxylic acid (DL-ATC) catalyzed by whole cells of Pseudomonas sp. was successfully applied for the production of L-cysteine. It was found, however, like most whole-cell biocatalytic processes, the accumulated L-cysteine produced obvious inhibition to the activity of biocatalyst and reduced the yield. To improve L-cysteine productivity, an anion exchange-based in situ product removal (ISPR) approach was developed. Several anion-exchange resins were tested to select a suitable adsorbent used in the bioconversion of DL-ATC for the in situ removal of L-cysteine. The strong basic anion-exchange resin 201 × 7 exhibited the highest adsorption capacity for L-cysteine and low adsorption for DL-ATC, which is a favorable option. With in situ addition of 60 g L(-1) resin 201 × 7, the product inhibition can be reduced significantly and 200 mmol L(-1) of DL-ATC was converted to L-cysteine with 90.4 % of yield and 28.6 mmol L(-1 )h(-1) of volumetric productivity. Compared to the bioconversion without the addition of resin, the volumetric productivity of L-cysteine was improved by 2.27-fold using ISPR method.

Sequence analysis, structure prediction and functional validation of phaC1/phaC2 genes of Pseudomonas sp. LDC-25 and its importance in polyhydroxyalkanoate accumulation

USDA-ARS?s Scientific Manuscript database

Polyhydroxyalkanoates (PHAs) are attractive biomaterials in both conventional medical devices and tissue engineering. PHA synthase is responsible for catalyzing the formation of polyhydroxyalkanoates (PHA), but its structural information is limited. Hence, the focus of this study is to predict 3D mo...

Isolation, plant colonization potential, and phenanthrene degradation performance of the endophytic bacterium Pseudomonas sp. Ph6-gfp

PubMed Central

Sun, Kai; Liu, Juan; Gao, Yanzheng; Jin, Li; Gu, Yujun; Wang, Wanqing

2014-01-01

This investigation provides a novel method of endophyte-aided removal of polycyclic aromatic hydrocarbons (PAHs) from plant bodies. A phenanthrene-degrading endophytic bacterium Pseudomonas sp. Ph6 was isolated from clover (Trifolium pratense L.) grown in a PAH-contaminated site. After being marked with the GFP gene, the colonization and distribution of strain Ph6-gfp was directly visualized in plant roots, stems, and leaves for the first time. After ryegrass (Lolium multiflorum Lam.) roots inoculation, strain Ph6-gfp actively and internally colonized plant roots and transferred vertically to the shoots. Ph6-gfp had a natural capacity to cope with phenanthrene in vitro and in planta. Ph6-gfp degraded 81.1% of phenanthrene (50 mg·L−1) in a culture solution within 15 days. The inoculation of plants with Ph6-gfp reduced the risks associated with plant phenanthrene contamination based on observations of decreased concentration, accumulation, and translocation factors of phenanthrene in ryegrass. Our results will have important ramifications in the assessment of the environmental risks of PAHs and in finding ways to circumvent plant PAH contamination. PMID:24964867

Optimization of critical medium components using response surface methodology for phenazine-1-carboxylic acid production by Pseudomonas sp. M-18Q.

PubMed

Yuan, Li-Li; Li, Ya-Qian; Wang, Yi; Zhang, Xue-Hong; Xu, Yu-Quan

2008-03-01

The optimal flask-shaking batch fermentation medium for phenazine-1-carboxylic acid (PCA) production by Pseudomonas sp. M-18Q, a qscR chromosomal inactivated mutant of the strain M18 was studied using statistical experimental design and analysis. The Plackett-Burman design (PBD) was used to evaluate the effects of eight medium components on the production of PCA, which showed that glucose and soytone were the most significant ingredients (P<0.05). The steepest ascent experiment was adopted to determine the optimal region of the medium composition. The optimum composition of the fermentation medium for maximum PCA yield, as determined on the basis of a five-level two-factor central composite design (CCD), was obtained by response surface methodology (RSM). The high correlation between the predicted and observed values indicated the validity of the model. A maximum PCA yield of 1240 mg/l was obtained at 17.81 g/l glucose and 11.47 g/l soytone, and the production was increased by 65.3% compared with that using the original medium, which was at 750 mg/l.

Development of eco-friendly bioplastic like PHB by distillery effluent microorganisms.

PubMed

Gangurde, Nilesh S; Sayyed, Riyaz Z; Kiran, Shashi; Gulati, Arvind

2013-01-01

During screening for poly-β-hydroxybutyrate (PHB) producing bacteria from distillery effluent sample, six out of 30 isolates comprising of three strains of Alcaligenes sp., two strains of Bacillus sp., and one strain of Pseudomonas sp. were found to accumulate varying levels of intracellular PHB. Amongst the various isolates, Alcaligenes sp. RZS4 was found as the potent PHB-producing organism, accumulating higher amounts of PHB. PHB productivity was further enhanced in the presence of oxygen, nitrogen-limiting conditions, and cloning of PHB synthesizing genes of Alcaligenes sp. RZS 4 into Escherichia coli. A twofold increase in PHB yield was obtained from recombinant E. coli vis-à-vis Alcaligenes sp.; the recombinant E. coli accumulated more PHB in NDMM, produced good amount of PHB in a single-stage cultivation process under both nutrient-rich and nutrient-deficient conditions. Extraction of PHB with acetone-alcohol (1:1) was found as suitable method for optimum extraction of PHB as this mixture selectively extracted PHB without affecting the non-PHB cell mass. PHB extract from recombinant E. coli showed the presence of C-H, =O stretching, =C-H deformation, =C-H, =CH, and =C-O functional groups characteristic of PHB.

Flexible exportation mechanisms of arthrofactin in Pseudomonas sp. MIS38.

PubMed

Lim, S P; Roongsawang, N; Washio, K; Morikawa, M

2009-07-01

To obtain further insights into transportation mechanisms of a most effective biosurfactant, arthrofactin in Pseudomonas sp. MIS38. A cluster genes arfA/B/C encodes an arthrofactin synthetase complex (ArfA/B/C). Downstream of the arfA/B/C lie genes encoding a putative periplasmic protein (ArfD, 362 aa) and a putative ATP-binding cassette transporter (ArfE, 651 aa), namely arfD and arfE, respectively. The arfA/B/C, arfD, and arfE form an operon suggesting their functional connection. Gene knockout mutants ArfD:Km, ArfE:Km, ArfD:Tc/ArfE:Km, and gene overexpression strains MIS38(pME6032_arfD/E) and ArfE:Km(pME6032_arfD/E) were prepared and analysed for arthrofactin production profiles. It was found that the production levels of arthrofactin were temporally reduced in the mutants or increased in the gene overexpression strains, but they eventually became similar level to that of MIS38. Addition of ABC transporter inhibitors, glibenclamide and sodium ortho-vanadate dramatically reduced the production levels of arthrofactin. This excludes a possibility that arthrofactin is exported by diffusion with the aid of its own high surfactant activity. ArfD/E is not an exclusive but a primary exporter of arthrofactin during early growth stage. Reduction in the arthrofactin productivity of arfD and arfE knockout mutants was eventually rescued by another ABC transporter system. Effects of arfD and arfE overexpression were evident only for 1-day cultivation. Multiple ATP dependent active transporter systems are responsible for the production of arthrofactin. Pseudomonas bacteria are characterized to be endued with multiple exporter and efflux systems for secondary metabolites including antibiotics, plant toxins, and biosurfactants. The present work demonstrates exceptionally flexible and highly controlled transportation mechanisms of a most effective lipopeptide biosurfactant, arthrofactin in Pseudomonas sp. MIS38. Because lipopeptide biosurfactants are known to enhance efficacy of bioactive compounds and arfA/B/C/D/E orthologous genes are also found in plant pathogenic P. fluorescens and P. syringae strains, the knowledge would also contribute to develop a technology controlling plant diseases.

Comparative analysis of 2,4,6-trinitrotoluene (TNT)-induced cellular responses and proteomes in Pseudomonas sp. HK-6 in two types of media.

PubMed

Cho, Yun-Seok; Lee, Bheong-Uk; Kahng, Hyung-Yeel; Oh, Kye-Heon

2009-04-01

TNT-induced cellular responses and proteomes in Pseudomonas sp. HK-6 were comparatively analyzed in two different media: basal salts (BS) and Luria broth (LB). HK-6 cells could not degrade more than 0.5 mM TNT with BS medium, while in LB medium, they exhibited the enhanced capability to degrade as much as 3.0 mM TNT. Analysis of total cellular fatty acids in HK-6 cells suggested that the relative abundance of several saturated or unsaturated fatty acids is altered under TNT-mediated stress conditions. Scanning electron microscopy showed the presence of perforations, irregular rod formations, and wrinkled extracellular surfaces in cells under TNT stress. Proteomic analysis of soluble protein fractions from HK-6 cultures grown with TNT as a substrate revealed 11 protein spots induced by TNT. Among these, seven proteins (including Alg8, AlgB, NirB, and the AhpC/Tsa family) were detected only in LB medium containing TNT. The proteins AspS, Tsf, and assimilatory nitrate reductase were increasingly expressed only in BS medium containing TNT. The protein dGTPase was found to be induced and expressed when cells were grown in either type of TNT-containing media. These results provide a better understanding of the cytotoxicity and survival mechanism used by Pseudomonas sp. HK-6 when placed under TNT stress conditions.

Antioxidant and antimicrobial potential of the Bifurcaria bifurcata epiphytic bacteria.

PubMed

Horta, André; Pinteus, Susete; Alves, Celso; Fino, Nádia; Silva, Joana; Fernandez, Sara; Rodrigues, Américo; Pedrosa, Rui

2014-03-24

Surface-associated marine bacteria are an interesting source of new secondary metabolites. The aim of this study was the isolation and identification of epiphytic bacteria from the marine brown alga, Bifurcaria bifurcata, and the evaluation of the antioxidant and antimicrobial activity of bacteria extracts. The identification of epiphytic bacteria was determined by 16S rRNA gene sequencing. Bacteria extracts were obtained with methanol and dichloromethane (1:1) extraction. The antioxidant activity of extracts was performed by quantification of total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and oxygen radical absorbance capacity (ORAC). Antimicrobial activities were evaluated against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Salmonella enteritidis, Staphylococcus aureus, Saccharomyces cerevisiae and Candida albicans. A total of 39 Bifurcaria bifurcata-associated bacteria were isolated and 33 were identified as Vibrio sp. (48.72%), Alteromonas sp. (12.82%), Shewanella sp. (12.26%), Serratia sp. (2.56%), Citricoccus sp. (2.56%), Cellulophaga sp. (2.56%), Ruegeria sp. (2.56%) and Staphylococcus sp. (2.56%). Six (15.38%) of the 39 bacteria Bifurcaria bifurcata-associated bacteria presented less than a 90% Basic Local Alignment Search Tool (BLAST) match, and some of those could be new. The highest antioxidant activity and antimicrobial activity (against B. subtilis) was exhibited by strain 16 (Shewanella sp.). Several strains also presented high antimicrobial activity against S. aureus, mainly belonging to Alteromonas sp. and Vibrio sp. There were no positive results against fungi and Gram-negative bacteria. Bifurcaria bifurcata epiphytic bacteria were revealed to be excellent sources of natural antioxidant and antimicrobial compounds.

Antioxidant and Antimicrobial Potential of the Bifurcaria bifurcata Epiphytic Bacteria

PubMed Central

Horta, André; Pinteus, Susete; Alves, Celso; Fino, Nádia; Silva, Joana; Fernandez, Sara; Rodrigues, Américo; Pedrosa, Rui

2014-01-01

Surface-associated marine bacteria are an interesting source of new secondary metabolites. The aim of this study was the isolation and identification of epiphytic bacteria from the marine brown alga, Bifurcaria bifurcata, and the evaluation of the antioxidant and antimicrobial activity of bacteria extracts. The identification of epiphytic bacteria was determined by 16S rRNA gene sequencing. Bacteria extracts were obtained with methanol and dichloromethane (1:1) extraction. The antioxidant activity of extracts was performed by quantification of total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and oxygen radical absorbance capacity (ORAC). Antimicrobial activities were evaluated against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Salmonella enteritidis, Staphylococcus aureus, Saccharomyces cerevisiae and Candida albicans. A total of 39 Bifurcaria bifurcata-associated bacteria were isolated and 33 were identified as Vibrio sp. (48.72%), Alteromonas sp. (12.82%), Shewanella sp. (12.26%), Serratia sp. (2.56%), Citricoccus sp. (2.56%), Cellulophaga sp. (2.56%), Ruegeria sp. (2.56%) and Staphylococcus sp. (2.56%). Six (15.38%) of the 39 bacteria Bifurcaria bifurcata-associated bacteria presented less than a 90% Basic Local Alignment Search Tool (BLAST) match, and some of those could be new. The highest antioxidant activity and antimicrobial activity (against B. subtilis) was exhibited by strain 16 (Shewanella sp.). Several strains also presented high antimicrobial activity against S. aureus, mainly belonging to Alteromonas sp. and Vibrio sp. There were no positive results against fungi and Gram-negative bacteria. Bifurcaria bifurcata epiphytic bacteria were revealed to be excellent sources of natural antioxidant and antimicrobial compounds. PMID:24663118

Is ozonation environmentally benign for reverse osmosis concentrate treatment? Four-level analysis on toxicity reduction based on organic matter fractionation.

PubMed

Weng, Jingxia; Jia, Huichao; Wu, Bing; Pan, Bingcai

2018-01-01

Ozonation is a promising option to treat reverse osmosis concentrate (ROC). However, a systematic understanding and assessment of ozonation on toxicity reduction is insufficient. In this study, ROC sampled from a typical industrial park wastewater treatment plant of China was fractionated into hydrophobic acid (HOA), hydrophobic base (HOB), hydrophobic neutral (HON), and hydrophilic fraction (HI). Systematic bioassays covering bacteria, algae, fish, and human cell lines were conducted to reveal the role of ozonation in toxicity variation of the four ROC fractions. HOA in the raw ROC exhibited the highest toxicity, followed by HON and HI. Ozonation significantly reduced total organic carbon (TOC) and UV 254 values in HOA, HON, and HI and their toxicity except in HOB. Correlation analysis indicated that chemical data (TOC and UV 254 ) of HOA and HON correlated well with their toxicities; however, poor correlations were observed for HOB and HI, suggesting that a battery of toxicity assays is necessary. This study indicates that TOC reduction during ozonation could not fully reflect the toxicity issue, and toxicity assessment is required in conjunction with the chemical data to evaluate the effectiveness of ozonation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reclassification of Alcaligenes latus strains IAM 12599T and IAM 12664 and Pseudomonas saccharophila as Azohydromonas lata gen. nov., comb. nov., Azohydromonas australica sp. nov. and Pelomonas saccharophila gen. nov., comb. nov., respectively.

PubMed

Xie, Cheng-Hui; Yokota, Akira

2005-11-01

The aim of this study was to clarify the taxonomic position of the nitrogen-fixing and hydrogen-oxidizing bacteria Alcaligenes latus strains IAM 12599T, IAM 12664 and IAM 12665 and Pseudomonas saccharophila IAM 14368T. It was found that the type strain of Alcaligenes latus, IAM 12599T, showed 99 x 9 and 96 x 1 % 16S rRNA gene sequence similarity to strains IAM 12665 and IAM 12664, respectively. A comparison using DNA-DNA hybridization suggested that strains IAM 12599T and IAM 12665 belong to a single species (89 x 7 %) and that strain IAM 12664 (35 x 1 %) forms a separate species. The phenotypic characteristics also support the conclusion that these bacteria should be identified as two species of a new genus: Azohydromonas lata gen. nov., comb. nov. (type strain IAM 12599T=DSM 1122T=LMG 3321T=ATCC 29712T; reference strain IAM 12665=DSM 1123=LMG 3325=ATCC 29714) and Azohydromonas australica sp. nov. (type strain IAM 12664T=DSM 1124T=LMG 3324T=ATCC 29713T). Pseudomonas saccharophila IAM 14368T was found to be closely related to the phototrophic bacterium Roseateles depolymerans, with 96 x 8 % 16S rRNA gene sequence similarity, but the two bacteria are quite different with respect to their metabolism and some significant phenotypic characteristics, suggesting that they cannot be included in a single genus. Further studies on their nifH gene sequences, G+C content of the DNA and cellular fatty acid composition confirm that Pseudomonas saccharophila should be reclassified: the name Pelomonas saccharophila gen. nov., comb. nov. is proposed, with the type strain IAM 14368T (=LMG 2256T=ATCC 15946T).

Degradation of ethyl mercaptan and its major intermediate diethyl disulfide by Pseudomonas sp. strain WL2.

PubMed

Wang, Xiangqian; Wu, Chao; Liu, Nan; Li, Sujing; Li, Wei; Chen, Jianmeng; Chen, Dongzhi

2015-04-01

A Pseudomonas sp. strain WL2 that is able to efficiently metabolize ethyl mercaptan (EM) into diethyl disulfide (DEDS) through enzymatic oxidation was isolated from the activated sludge of a pharmaceutical wastewater plant. One hundred percent removal of 113.5 mg L(-1) EM and 110.3 mg L(-1) DEDS were obtained within 14 and 32 h, respectively. A putative EM degradation pathway that involved the catabolism via DEDS was proposed, which indicated DEDS were further mineralized into carbon dioxide (CO2), bacterial cells, and sulfate (SO4 (2-)) through the transformation of element sulfur and ethyl aldehyde. Degradation kinetics for EM and DEDS with different initial concentrations by strain WL2 were evaluated using Haldane-Andrews model with maximum specific degradation rates of 3.13 and 1.33 g g(-1) h(-1), respectively, and maximum degradation rate constants of 0.522 and 0.175 h(-1) using pseudo-first-order kinetic model were obtained. Results obtained that aerobic degradation of EM by strain WL2 was more efficient than those from previous studies. Substrate range studies of strain WL2 demonstrated its ability to degrade several mercaptans, disulfides, aldehydes, and methanol. All the results obtained highlight the potential of strain WL2 for the use in the biodegradation of volatile organic sulfur compounds (VOSCs).

Antimicrobial and Antimycobacterial Activity of Cyclostellettamine Alkaloids from Sponge Pachychalina sp.

PubMed Central

de Oliveira, Jaine H. H. L.; Seleghim, Mirna H. R.; Timm, Christoph; Grube, Achim; Köck, Matthias; Nascimento, Gislene G.F.; Martins, Ana Claudia T.; Silva, Elissa G. O.; de Souza, Ana Olívia; Minarini, Paulo R. R.; Galetti, Fabio C. S.; Silva, Célio L.; Hajdu, Eduardo; Berlinck, Roberto G. S.

2006-01-01

Cyclostellettamines A – F (1 – 6) isolated from the sponge Pachychalina sp. and cyclostellettamines G - I, K and L (7 – 11) obtained by synthesis were evaluated in bioassays of antimicrobial activity against susceptible and antibiotic-resistant Staphylococcus aureus, Pseudomonas aeruginosa and antibiotic-susceptible Escherichia coli and Candida albicans, as well as in antimycobacterial activity against Mycobacterium tuberculosis H37Rv bioassays. The results obtained indicated that cyclostellettamines display different antimicrobial activity depending on the alkyl-chain size, suggesting that, if a mechanism-of action is implied, it is dependent on the distance between the two pyridinium moieties of cyclostellettamines.

Ceramidastin, a novel bacterial ceramidase inhibitor, produced by Penicillium sp. Mer-f17067.

PubMed

Inoue, Hiroyuki; Someno, Tetsuya; Kato, Taira; Kumagai, Hiroyuki; Kawada, Manabu; Ikeda, Daishiro

2009-02-01

Decrease of ceramide in the skin is one of the aggravating factors of atopic dermatitis. The skin is often infected by ceramidase-producing bacteria, such as Pseudomonas aeruginosa. The bacterial ceramidase then degrades ceramide in the skin. To develop anti-atopic dermatitis drugs, we searched for ceramidase inhibitors, which led to the discovery of ceramidastin, a novel inhibitor of bacterial ceramidase, from the culture broth of Penicillium sp. Mer-f17067. Ceramidastin inhibited the bacterial ceramidase with an IC(50) value of 6.25 microg ml(-1). Here we describe the isolation, physicochemical properties, structure determination and biological activity of ceramidastin.

Differential Response of Potato Toward Inoculation with Taxonomically Diverse Plant Growth Promoting Rhizobacteria.

PubMed

Naqqash, Tahir; Hameed, Sohail; Imran, Asma; Hanif, Muhammad Kashif; Majeed, Afshan; van Elsas, Jan Dirk

2016-01-01

Rhizosphere engineering with beneficial plant growth promoting bacteria offers great promise for sustainable crop yield. Potato is an important food commodity that needs large inputs of nitrogen and phosphorus fertilizers. To overcome high fertilizer demand (especially nitrogen), five bacteria, i.e., Azospirillum sp. TN10, Agrobacterium sp. TN14, Pseudomonas sp. TN36, Enterobacter sp. TN38 and Rhizobium sp. TN42 were isolated from the potato rhizosphere on nitrogen-free malate medium and identified based on their 16S rRNA gene sequences. Three strains, i.e., TN10, TN38, and TN42 showed nitrogen fixation (92.67-134.54 nmol h(-1)mg(-1) protein), while all showed the production of indole-3-acetic acid (IAA), which was significantly increased by the addition of L-tryptophan. Azospirillum sp. TN10 produced the highest amount of IAA, as measured by spectrophotometry (312.14 μg mL(-1)) and HPLC (18.3 μg mL(-1)). Inoculation with these bacteria under axenic conditions resulted in differential growth responses of potato. Azospirillum sp. TN10 incited the highest increase in potato fresh and dry weight over control plants, along with increased N contents of shoot and roots. All strains were able to colonize and maintain their population densities in the potato rhizosphere for up to 60 days, with Azospirillum sp. and Rhizobium sp. showing the highest survival. Plant root colonization potential was analyzed by transmission electron microscopy of root sections inoculated with Azospirillum sp. TN10. Of the five test strains, Azospirillum sp. TN10 has the greatest potential to increase the growth and nitrogen uptake of potato. Hence, it is suggested as a good candidate for the production of potato biofertilizer for integrated nutrient management.

Bioremediation of kerosene I: A case study in liquid media.

PubMed

Gouda, Mona K; Omar, Sanaa H; Chekroud, Zohra A; Nour Eldin, Hemdan M

2007-11-01

The ability of different local isolates in addition to some isolates from Germany to degrade kerosene in liquid medium was studied. The results showed that the percent of kerosene degradation varied among the different organisms and that 59-94% of kerosene was degraded after 21d. Two local isolates (Pseudomonas sp. AP and Pseudomonas sp. CK) and one German isolate (Gordonia sp. DM) were selected for this study. The addition of wheat bran, as co-substrate, stimulated the kerosene degradation by the two local strains, while glucose inhibited the degradation rate using the three organisms with different rates. Ammonium nitrate and urea was the best nitrogen sources. The use of superphosphate (as phosphorus source) in the presence of urea stimulates the degradation rate. It was also observed that the addition of 1% surfactants, like Triton X-100, Igepal, Tergitol, or Tween 20 and 80 enhanced the kerosene degradation. The degradation percent lied between 94% and 98%. The ability of the tested organisms to degrade kerosene concentration from 2% to 8% was evaluated. It was found that the three organisms degraded about 65-85% from 8% kerosene after 21d. The use of rice straw-immobilized cells reduced the time of degradation and enhanced the degradation ability of the organisms. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the presence of a common protein band when the tested organisms were grown on kerosene.

Microbiological quality of drinking water from dispensers in roadside restaurants of Bangladesh.

PubMed

Moniruzzaman, M; Akter, S; Islam, M A; Mia, Z

2011-01-15

The microbiological status of water from dispensers in different roadside restaurants of Dhaka city and Savar area was analyzed in this study. Seven samples from Dhaka and 8 samples of Savar were checked. The heterotrophic plate count was in a range of 1.0 x 10(3) CFU mL(-1) to 2.0 x 10(4) CFU mL(-1) (from new bottles), 1.0 x 10(3) to 1.5 x 10(4) CFU mL(-1) (after dispensation), and 1.5 x 10(3) CFU mL(-1) to 1.0 x l0(5) CFU mL(-1) (from serving glass). In several of the samples, the heterotrophic plate count was higher than the count in water from new bottle or after dispensation, suggesting added contamination from the serving glass. 80% of the samples were contaminated with total and fecal coliform bacteria, which render these waters unacceptable for human consumption. The samples were found to contain gram negative bacteria like E coli, Shigella sp., Klebsiella sp., Enterobacter sp., Pseudomonas sp., and Salmonella sp., which are potential pathogens and thus pose a serious threat to public health. This study elucidates the importance of monitoring the bottling companies and the restaurants and put them under strict regulations to prevent future outbreak of any water borne diseases caused by consumption of dispensed water.

Electrochemical Characteristics of Cell Cultured Ti-Nb-Zr Alloys After Nano-Crystallized Si-HA Coating.

PubMed

Jeong, Yong-Hoon; Choe, Han-Cheol

2015-01-01

The aim of this study was to investigate the electrochemical characteristics of nano crystallized Si-HA coating on Ti-Nb-Zr alloy after human osteoblast like (HOB) cell attachment. The Ti-Nb-Zr alloy was manufactured with 35 wt.% of Nb and 10 wt.% of Zr by arc melting furnace to appropriate physical properties as biomaterials. The HA and Si-substituted coatings were prepared by electron-beam physical vapor deposition method with 0.5, 0.8 and 1.2 wt.% of Si contents, and nano aging treatment was performed 500 degrees C for 1 h. The characteristics of coating surface were analyzed by field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction, respectively. To evaluate of cell attachment on cell cultured surface, the potentiodynamic test was performed on the surface using HOB cells. The results showed that the Si-HA coating surface showed higher tendency of cell attachment than that of single HA coating, corrosion resistance value was increased by dense of cell attachment.

Biodegradation of 2,4'-dichlorobiphenyl, a congener of polychlorinated biphenyl, by Pseudomonas isolates GSa and GSb.

PubMed

Gayathri, D; Shobha, K J

2015-08-01

Bioegradation of 2,4'-dichlorobiphenyl (2,4 CB), by two isolates of Pseudomonas (GSa and GSb) was compared using GC-MS. Transformer oil polluted soil was used for the isolation of 2,4 CB degrading bacteria. GC-MS analysis of the solvent extracts obtained from Pseudomonas sp. GSa spent culture indicated the presence of Phenol 2,6-bis (1,1-dimethyl)-4-methyl (C15H24O). Further, the enzyme analysis of the cell free extracts showed the presence of 2,4'-dichlorobiphenyl dehalogenase (CBD), 2,4'-dichlorobiphenyl-NADPH-oxido-reductase (2,4 CBOR) and 2,3-dihydroxybiphenyl-NADPH-oxido-reductase (2,3 DHOR) with specific activity of 6.00, 0.4 and 0.22 pmol/min/mg of protein, suggesting that dechlorination as an important step during 2,4 CB catabolism. Further, the cell free extract of GSb showed only 2,4'-dichlorobiphenyl-NADPH-oxido-reductase (2,4 CBOR) and 2,3-dihydroxybiphenyl-NADPH-oxido-reductase (2,3 DHOR), with specific activity of 0.3 and 0.213 μmol/min/mg of protein, suggesting attack on non-chlorinated aromatic ring of 2,4 CB, releasing chlorinated intermediates which are toxic to the environment. Although, both the isolated bacteria (GSa and GSb) belong to Pseudomonas spp., they exhibited different metabolic potential.

Pseudomonas canadensis sp. nov., a biological control agent isolated from a field plot under long-term mineral fertilization.

PubMed

Tambong, James T; Xu, Renlin; Bromfield, Eden S P

2017-04-01

The bacterial strain 2-92T, isolated from a field plot under long-term (>40 years) mineral fertilization, exhibited in vitro antagonistic properties against fungal pathogens. A polyphasic approach was undertaken to verify its taxonomic status. Strain 2-92T was Gram-reaction-negative, aerobic, non-spore-forming, motile by one or more flagella, and oxidase-, catalase- and urease-positive. The optimal growth temperature of strain 2-92T was 30 °C. 16S rRNA gene sequence analysis demonstrated that the strain is related to species of the genus Pseudomonas. Phylogenetic analysis of six housekeeping genes (dnaA, gyrB, recA, recF, rpoB and rpoD) revealed that strain 2-92T clustered as a distinct and well separated lineage with Pseudomonassimiae as the most closely related species. Polar lipid and fatty acid compositions corroborated the taxonomic position of strain 2-92T in the genus Pseudomonas. Phenotypic characteristics from carbon utilization tests could be used to differentiate strain 2-92T from closely related species of the genus Pseudomonas. DNA-DNA hybridization values (wet laboratory and genome-based) and average nucleotide identity data confirmed that this strain represents a novel species. On the basis of phenotypic and genotypic characteristics, it is concluded that this strain represents a separate novel species for which the name Pseudomonas canadensis sp. nov. is proposed, with type strain 2-92T (=LMG 28499T=DOAB 798T). The DNA G+C content is 60.30 mol%.

Antimicrobial metabolites from the plant endophytic fungus Penicillium sp.

PubMed

Yang, Ming-Hua; Li, Tian-Xiao; Wang, Ying; Liu, Rui-Huan; Luo, Jun; Kong, Ling-Yi

2017-01-01

Five rare dichloro aromatic polyketides (1-5) were obtained from an endophytic fungus Penicillium sp., along with five known metabolites (6-10). Their structures were elucidated by extensive spectroscopic analysis, Mosher methods, as well as [Rh 2 (OCOCF 3 ) 4 ]-induced electronic circular dichroism (ECD) experiments. Compounds 2-4 and 6 structurally involved acyclic 1.3-diols, the uneasy configuration determinations of which were well carried out by double-derivation NMR methods. Compounds 1-10 were evaluated for their antibacterial and antifungal activities against five strains of human pathogenic microorganisms. Helvolic acid (7) showed potent inhibitory effects against Staphylococcus aureus and Pseudomonas aeruginosa with MIC (minimum inhibitory concentration) values of 5.8 and 4.6μg/mL, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of obstructive sleep apnea in non-cystic fibrosis bronchiectasis: A cross-sectional study

PubMed Central

Urbano, Jessica Julioti; Santos, Israel Reis; Silva, Anderson Soares; Perez, Eduardo Araújo; Souza, Ângela Honda; Nascimento, Oliver Augusto; Jardim, José Roberto; Insalaco, Giuseppe; Oliveira, Luis Vicente Franco; Stirbulov, Roberto

2017-01-01

The relationship between sleep disorders and bronchiectasis has not been well described. We hypothesize that, due to the irreversible dilatation of the bronchi, the presence of secretions, and airflow obstruction, patients with non-cystic fibrosis bronchiectasis may be predisposed to hypoxemia during sleep, or to symptoms that may lead to arousal. A cross-sectional observational study was performed involving 49 patients with a clinical diagnosis of non-cystic fibrosis bronchiectasis (NCFB). All patients underwent clinical evaluation, spirometry, and polysomnography, and were evaluated for the presence of excessive daytime sleepiness (EDS) and risk of obstructive sleep apnea (OSA). The mean age of the participants was 50.3 ± 13.6 years; 51.1% of patients were male and had a mean body mass index of 23.8 ± 3.4 kg/m2. The mean total sleep time (TST) was 325.15 ± 64.22 min with a slight reduction in sleep efficiency (84.01 ± 29.2%). Regarding sleep stages, stage 1 sleep and REM sleep were abnormal. OSA was present in 40.82% of the patients. The mean arousal index was 5.6 ± 2.9/h and snoring was observed in 71.43% of the patients. The oxygen desaturation index (ODI) was 14.35 ± 15.36/h, mean minimum oxygen saturation (SpO2 nadir) was 83.29 ± 7.99%, and mean TST with an SpO2 less than 90% was 30.21 ± 60.48 min. EDS was exhibited by 53.06% of the patients and 55.1% were at high risk of developing OSA. The patients infected by Pseudomonas aeruginosa had higher apnea-hypopnea indices, ODI, and TST with SpO2 < 90%, and lower values of SpO2 nadir. Adult patients with clinically stable NCFB, especially those infected by Pseudomonas aeruginosa, display EDS and a high prevalence of OSA, associated with considerable oxygen desaturation during sleep. PMID:28972989

Evaluation of obstructive sleep apnea in non-cystic fibrosis bronchiectasis: A cross-sectional study.

PubMed

Faria Júnior, Newton Santos; Urbano, Jessica Julioti; Santos, Israel Reis; Silva, Anderson Soares; Perez, Eduardo Araújo; Souza, Ângela Honda; Nascimento, Oliver Augusto; Jardim, José Roberto; Insalaco, Giuseppe; Oliveira, Luis Vicente Franco; Stirbulov, Roberto

2017-01-01

The relationship between sleep disorders and bronchiectasis has not been well described. We hypothesize that, due to the irreversible dilatation of the bronchi, the presence of secretions, and airflow obstruction, patients with non-cystic fibrosis bronchiectasis may be predisposed to hypoxemia during sleep, or to symptoms that may lead to arousal. A cross-sectional observational study was performed involving 49 patients with a clinical diagnosis of non-cystic fibrosis bronchiectasis (NCFB). All patients underwent clinical evaluation, spirometry, and polysomnography, and were evaluated for the presence of excessive daytime sleepiness (EDS) and risk of obstructive sleep apnea (OSA). The mean age of the participants was 50.3 ± 13.6 years; 51.1% of patients were male and had a mean body mass index of 23.8 ± 3.4 kg/m2. The mean total sleep time (TST) was 325.15 ± 64.22 min with a slight reduction in sleep efficiency (84.01 ± 29.2%). Regarding sleep stages, stage 1 sleep and REM sleep were abnormal. OSA was present in 40.82% of the patients. The mean arousal index was 5.6 ± 2.9/h and snoring was observed in 71.43% of the patients. The oxygen desaturation index (ODI) was 14.35 ± 15.36/h, mean minimum oxygen saturation (SpO2 nadir) was 83.29 ± 7.99%, and mean TST with an SpO2 less than 90% was 30.21 ± 60.48 min. EDS was exhibited by 53.06% of the patients and 55.1% were at high risk of developing OSA. The patients infected by Pseudomonas aeruginosa had higher apnea-hypopnea indices, ODI, and TST with SpO2 < 90%, and lower values of SpO2 nadir. Adult patients with clinically stable NCFB, especially those infected by Pseudomonas aeruginosa, display EDS and a high prevalence of OSA, associated with considerable oxygen desaturation during sleep.

Effect of Cys85 on biochemical properties and biological function of human SP-A variants

PubMed Central

Wang, Guirong; Myers, Catherine; Mikerov, Anatoly; Floros, Joanna

2008-01-01

Four “core” amino acid differences within the collagen-like domain distinguish the human surfactant proteins A1 (SP-A1) variants from the SP-A2 variants. One of these, cysteine 85 that could form intermolecular disulfide bonds, is present in SP-A1 (Cys85) and absent in SP-A2 (Arg85). We hypothesized that residue85 affects both structure and function of SP-A1 and SP-A2 variants. To test this, wild type (WT) variants, 6A2 of SP-A1 and 1A0 of SP-A2, and their mutants (6A2(C85R) and 1A0(R85C)), were generated and studied. We found: 1) Residue85 affected the binding ability to mannose and the oligomerization pattern of SP-As. The 1A0(R85C) and 6A2(C85R) patterns were similar and/or resembled those of WT 6A2 and 1A0, respectively. 2) Both SP-A WT and mutants differentially induced rough LPS and Pseudomonas aeruginosa aggregation in the following order: 1A0 > 6A2 > 6A2(C85R) > 1A0(R85C) for Re-LPS aggregation, and 1A0 > 6A2 = 6A2(C85R) = 1A0(R85C) for bacterial aggregation. 3) SP-A WT and mutants enhanced phagocytosis of P. aeruginosa by rat alveolar macrophages. Their phagocytic index order was: 6A2(C85R) > 1A0 > 6A2 = 1A0(R85C). The activity of mutant 1A0(C85R) was significantly lower from WT 1A0 but similar to 6A2. Compared to WT 6A2, the 6A2(C85R) mutant exhibited a significantly higher activity. These results indicate that SP-A variant/mutant with Arg85 exhibits higher ability to enhance bacterial phagocytosis than that with Cys85. Residue85 plays a important role in the structure and function of SP-A, and is a major factor for the differences between SP-A1 and SPA2 variants. PMID:17580966

Characterization of a cold-adapted esterase and mutants from a psychotolerant Pseudomonas sp. strain.

PubMed

Dong, Juan; Gasmalla, Mohammed A A; Zhao, Wei; Sun, Jingtao; Liu, Wenyu; Wang, Mingming; Han, Liang; Yang, Ruijin

2017-09-01

A cold-adapted esterase-producing strain named T1-39 was isolated from Glacier No. 1, Tianshan, People's Republic of China and identified as Pseudomonas sp. from 16S rRNA sequence analysis. The esterase (EstT1-39) secreted by this strain preferentially hydrolyzed esters of glycerol with short- and medium-chain fatty acids. Mutants of T1-39 were generated by the atmospheric and room temperature plasma method and screened for enhanced esterase activity. Among all the mutants, strain TB11 had 4.45-fold higher esterase productivity than T1-39, with high genetic stability over 10 generations of continuous cultivation. Maximum activity of EstT1-39 and EstTB11 was observed at 30 ℃, pH 9.0 and 25 ℃, pH 8.5, respectively. EstTB11 was thermally more stable (50 ℃ for 1 H) and active over a broader pH range than EstT1-39. EstTB11 also retained 38% of its maximal activity at 0 ℃ and was found to be able to hydrolyze milk fats into short- and medium-chain fatty acids at 4 ℃. The characteristics of EstT1-39 made it a cold-adapted enzyme and the EstTB11 from the mutant, with its higher activity at lower temperatures, may be suitable for the production of aromas and flavors in the dairy industry. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

Oil and Hydrocarbon Spill Bioremediation Product and Application Technology

DTIC Science & Technology

1993-05-01

Kiebsiella Heiminthosporium Lactobacillus Mucor Leucothrix Oidiadendrumn Moraxella Paecylomyces Nocardia Phialophora Peptococcus Penicillium Pseudomonas...sludge’ Alkanes PsoudomonasPA rthroba eter, A cineeofbacter, yeasts, Penicillium sp., Cunninghamells blakesleearia, Absidiaglauca, Mucor spif n-Alkanes

Degradation of carbazole, dibenzothiophene, and dibenzofuran at low temperature by Pseudomonas sp. strain C3211.

PubMed

Jensen, Anne-Mette; Finster, Kai Waldemar; Karlson, Ulrich

2003-04-01

Pseudomonas sp. strain C3211 was isolated from a temperate climate soil contaminated with creosote. This strain was able to degrade carbazole, dibenzothiophene and dibenzofuran at 10 degrees C with acetone as a co-substrate. When dibenzothiophene was degraded by strain C3211, an orange compound, which absorbed at 472 nm, accumulated in the medium. Degradation of dibenzofuran was followed by accumulation of a yellowish compound, absorbing at 462 nm. The temperature optimum of strain C3211 for degradation of dibenzothiophene and dibenzofuran was at 20 to 21 degrees C, while the maximum temperature for degradation was at 27 degrees C. Both compounds were degraded at 4 degrees C. Degradation at 10 degrees C was faster than degradation at 25 degrees C. This indicates that strain C3211 is adapted to life at low temperatures.

Bacteriophage SP6 encodes a second tailspike protein that recognizes Salmonella enterica serogroups C{sub 2} and C{sub 3}

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

Gebhart, Dana; Williams, Steven R.; Scholl, Dean,

SP6 is a salmonella phage closely related to coliphage K1-5. K1-5 is notable in that it encodes two polysaccharide-degrading tailspike proteins, an endosialidase that allows it to infect E. coli K1, and a lyase that enables it to infect K5 strains. SP6 is similar to K1-5 except that it encodes a P22-like endorhamnosidase tailspike, gp46, allowing it to infect group B Salmonella. We show here that SP6 can also infect Salmonella serogroups C{sub 2} and C{sub 3} and that a mutation in a putative second tailspike, gp47, eliminates this specificity. Gene 47 was fused to the coding region of themore » N-terminal portion of the Pseudomonas aeruginosa R2 pyocin tail fiber and expressed in trans such that the fusion protein becomes incorporated into pyocin particles. These pyocins, termed AvR2-SP47, killed serogroups C{sub 2} and C{sub 3}Salmonella. We conclude that SP6 encodes two tail proteins providing it a broad host range among Salmonella enterica. - Highlights: • SP6 is a “dual specificity” bacteriophage that encodes two different receptor binding proteins giving it a broad host range. • These receptor binding proteins can be used to re-target the spectrum of R-type bacteriocins to Salmonella enterica. • Both SP6 and the engineered R-type bacteriocins can kill the Salmonella serovars most associated with human disease making them attractive for development as antimicrobial agents.« less

Strain identification and quorum sensing inhibition characterization of marine-derived Rhizobium sp. NAO1

NASA Astrophysics Data System (ADS)

Chang, Hong; Zhou, Jin; Zhu, Xiaoshan; Yu, Shenchen; Chen, Lu; Jin, Hui; Cai, Zhonghua

2017-03-01

A novel strategy for combating pathogens is through the ongoing development and use of anti-quorum sensing (QS) treatments such as therapeutic bacteria or their anti-QS substances. Relatively little is known about the bacteria that inhabit the open ocean and of their potential anti-pathogenic attributes; thus, in an initiative to identify these types of therapeutic bacteria, planktonic microbes from the North Atlantic Ocean were collected, isolated, cultured and screened for anti-QS activity. Screening analysis identified one such strain, Rhizobium sp. NAO1. Extracts of Rhizobium sp. NAO1 were identified via ultra-performance liquid chromatography (UPLC) analysis. They were shown to contain N-acyl homoserine lactone (AHL)-based QS analogues (in particular, the N-butyryl homoserine lactone (C4-AHL) analogue) and could disrupt biofilm formation by Pseudomonas aeruginosa PAO1. QS inhibition was confirmed using confocal scanning laser microscopy and growth curves, and it was shown to occur in a dose-dependent manner without affecting bacterial growth. Secondary metabolites of Rhizobium sp. NAO1 inhibited PAO1 pathogenicity by downregulating AHL-mediated virulence factors such as elastase activity and siderophore production. Furthermore, as a result of biofilm structure damage, the secondary metabolite products of Rhizobium sp. NAO1 significantly increased the sensitivity of PAO1 to aminoglycoside antibiotics. Our results demonstrated that Rhizobium sp. strain NAO1 has the ability to disrupt P. aeruginosa PAO1 biofilm architecture, in addition to attenuating P. aeruginosa PAO1 virulence factor production and pathogenicity. Therefore, the newly identified ocean-derived Rhizobium sp. NAO1 has the potential to serve as a QS inhibitor and may be a new microbial resource for drug development.

Pip, a Novel Activator of Phenazine Biosynthesis in Pseudomonas chlororaphis PCL1391▿ †

PubMed Central

Girard, Geneviève; Barends, Sharief; Rigali, Sébastien; van Rij, E. Tjeerd; Lugtenberg, Ben J. J.; Bloemberg, Guido V.

2006-01-01

Secondary metabolites are important factors for interactions between bacteria and other organisms. Pseudomonas chlororaphis PCL1391 produces the antifungal secondary metabolite phenazine-1-carboxamide (PCN) that inhibits growth of Fusarium oxysporum f. sp. radius lycopersici the causative agent of tomato foot and root rot. Our previous work unraveled a cascade of genes regulating the PCN biosynthesis operon, phzABCDEFGH. Via a genetic screen, we identify in this study a novel TetR/AcrR regulator, named Pip (phenazine inducing protein), which is essential for PCN biosynthesis. A combination of a phenotypical characterization of a pip mutant, in trans complementation assays of various mutant strains, and electrophoretic mobility shift assays identified Pip as the fifth DNA-binding protein so far involved in regulation of PCN biosynthesis. In this regulatory pathway, Pip is positioned downstream of PsrA (Pseudomonas sigma factor regulator) and the stationary-phase sigma factor RpoS, while it is upstream of the quorum-sensing system PhzI/PhzR. These findings provide further evidence that the path leading to the expression of secondary metabolism gene clusters in Pseudomonas species is highly complex. PMID:16997957

Biosynthesis of 2-Hydroxyacid-Containing Polyhydroxyalkanoates by Employing butyryl-CoA Transferases in Metabolically Engineered Escherichia coli.

PubMed

David, Yokimiko; Joo, Jeong Chan; Yang, Jung Eun; Oh, Young Hoon; Lee, Sang Yup; Park, Si Jae

2017-11-01

The authors previously reported the production of polyhydroxyalkanoates (PHAs) containing 2-hydroxyacid monomers by expressing evolved Pseudomonas sp. 6-19 PHA synthase and Clostridium propionicum propionyl-CoA transferase in engineered microorganisms. Here, the authors examined four butyryl-CoA transferases from Roseburia sp., Eubacterium hallii, Faecalibacterium prausnitzii, and Anaerostipes caccae as potential CoA-transferases to support synthesis of polymers having 2HA monomer. In vitro activity analyses of the four butyryl-CoA transferases suggested that each butyryl-CoA transferase has different activities towards 2-hydroxybutyrate (2HB), 3-hydroxybutyrate (3HB), and lactate (LA). When Escherichia coli XL1-Blue expressing Pseudomonas sp. 6-19 PhaC1437 along with one butyryl-CoA transferase is cultured in chemically defined MR medium containing 20 g L -1 of glucose, 2 g L -1 of sodium 3-hydroxybutyrate, and various concentrations of sodium 2-hydroxybutyrate, PHAs consisting of 3HB, 2HB, and LA are produced. The monomer composition of PHAs agreed well with the substrate specificities of butyryl-CoA transferases from E. hallii, F. prausnitzii, and A. caccae, but not Roseburia sp. When E. coli XL1-Blue expressing PhaC1437 and E. hallii butyryl-CoA transferase is cultured in MR medium containing 20 g L -1 of glucose and 2 g L -1 of sodium 2-hydroxybutyrate, P(65.7 mol% 2HB-co-34.3 mol% LA) is produced with the highest PHA content of 30 wt%. Butyryl-CoA transferases also supported the production of P(3HB-co-2HB-co-LA) from glucose as the sole carbon source in E. coli XL1-Blue strains when one of these bct genes is expressed with phaC1437, cimA3.7, leuBCD, panE, and phaAB genes. Butyryl-CoA transferases characterized in this study can be used for engineering of microorganisms that produce PHAs containing novel 2-hydroxyacid monomers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced cadmium phytoremediation of Glycine max L. through bioaugmentation of cadmium-resistant bacteria assisted by biostimulation.

PubMed

Rojjanateeranaj, Pongsarun; Sangthong, Chirawee; Prapagdee, Benjaphorn

2017-10-01

This study examined the potential of three strains of cadmium-resistant bacteria, including Micrococcus sp., Pseudomonas sp. and Arthrobacter sp., to promote root elongation of Glycine max L. seedlings, soil cadmium solubility and cadmium phytoremediation in G. max L. planted in soil highly polluted with cadmium with and without nutrient biostimulation. Micrococcus sp. promoted root length in G. max L. seedlings under toxic cadmium conditions. Soil inoculation with Arthrobacter sp. increased the bioavailable fraction of soil cadmium, particularly in soil amended with a C:N ratio of 20:1. Pot culture experiments observed that the highest plant growth was in Micrococcus sp.-inoculated plants with nutrient biostimulation. Cadmium accumulation in the roots, stems and leaves of G. max L. was significantly enhanced by Arthrobacter sp. with nutrient biostimulation. A combined use of G. max L. and Arthrobacter sp. with nutrient biostimulation accelerated cadmium phytoremediation. In addition, cadmium was retained in roots more than in stems and leaves and G. max L. had the lowest translocation factor at all growth stages, suggesting that G. max L. is a phytostabilizing plant. We concluded that biostimulation-assisted bioaugmentation is an important strategy for improving cadmium phytoremediation efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Statistical media design for efficient polyhydroxyalkanoate production in Pseudomonas sp. MNNG-S.

PubMed

Saranya, V; Rajeswari, V; Abirami, P; Poornimakkani, K; Suguna, P; Shenbagarathai, R

2016-07-03

Polyhydroxyalkanoate (PHA) is a promising polymer for various biomedical applications. There is a high need to improve the production rate to achieve end use. When a cost-effective production was carried out with cheaper agricultural residues like molasses, traces of toxins were incorporated into the polymer, which makes it unfit for biomedical applications. On the other hand, there is an increase in the popularity of using chemically defined media for the production of compounds with biomedical applications. However, these media do not exhibit favorable characteristics such as efficient utilization at large scale compared to complex media. This article aims to determine the specific nutritional requirement of Pseudomonas sp. MNNG-S for efficient production of polyhydroxyalkanoate. Response surface methodology (RSM) was used in this study to statistically design for PHA production based on the interactive effect of five significant variables (sucrose; potassium dihydrogen phosphate; ammonium sulfate; magnesium sulfate; trace elements). The interactive effects of sucrose with ammonium sulfate, ammonium sulfate with combined potassium phosphate, and trace element with magnesium sulfate were found to be significant (p < .001). The optimization approach adapted in this study increased the PHA production more than fourfold (from 0.85 g L(-1) to 4.56 g L(-1)).

Gene Expression of Lytic Endopeptidases AlpA and AlpB from Lysobacter sp. XL1 in Pseudomonads.

PubMed

Tsfasman, Irina M; Lapteva, Yulia S; Krasovskaya, Ludmila A; Kudryakova, Irina V; Vasilyeva, Natalia V; Granovsky, Igor E; Stepnaya, Olga A

2015-01-01

Development of an efficient expression system for (especially secreted) bacterial lytic enzymes is a complicated task due to the specificity of their action. The substrate for such enzymes is peptidoglycan, the main structural component of bacterial cell walls. For this reason, expression of recombinant lytic proteins is often accompanied with lysis of the producing bacterium. This paper presents data on the construction of an inducible system for expression of the lytic peptidases AlpA and AlpB from Lysobacter sp. XL1 in Pseudomonas fluorescens Q2-87, which provides for the successful secretion of these proteins into the culture liquid. In this system, the endopeptidase gene under control of the T7lac promoter was integrated into the bacterial chromosome, as well as the Escherichia coli lactose operon repressor protein gene. The T7 pol gene under lac promoter control, which encodes the phage T7 RNA polymerase, is maintained in Pseudomonas cells on the plasmids. Media and cultivation conditions for the recombinant strains were selected to enable the production of AlpA and AlpB by a simple purification protocol. Production of recombinant lytic enzymes should contribute to the development of new-generation antimicrobial drugs whose application will not be accompanied by selection of resistant microorganisms. © 2015 S. Karger AG, Basel.

Mammalian cell line-based bioassays for toxicological evaluation of landfill leachate treated by Pseudomonas sp. ISTDF1.

PubMed

Ghosh, Pooja; Das, Mihir Tanay; Thakur, Indu Shekhar

2014-01-01

Landfill leachate has become a serious environmental concern because of the presence of many hazardous compounds which even at trace levels are a threat to human health and environment. Therefore, it is important to assess the toxicity of leachate generated and discharge it conforming to the safety standards. The present work examined the efficiency of an earlier reported Pseudomonas sp. strain ISTDF1 for detoxification of leachate collected from Okhla landfill site (New Delhi, India). GC-MS analysis performed after treatment showed the removal of compounds like alpha-limonene diepoxide, brominated dioxin-2-one, Bisphenol A, nitromusk, phthalate derivative, and nitrobenzene originally found in untreated leachate. ICP-AES analysis for heavy metals also showed reduction in concentrations of Zn, Cd, Cr, Fe, Ni, and Pb bringing them within the limit of safety discharge. Methyl tetrazolium (MTT) assay for cytotoxicity, alkaline comet assay for genotoxicity, and 7-ethoxyresorufin-O-deethylase (EROD) assay for dioxin-like behavior were carried out in human hepato-carcinoma cell line HepG2 to evaluate the toxic potential of treated and untreated leachates. The bacterium reduced toxicity as shown by 2.5-fold reduction of MTT EC50 value, 7-fold reduction in Olive Tail Moment, and 2.8-fold reduction in EROD induction after 240 h of bacterial treatment.

In vitro suppression of fungi caused by combinations of apparently non-antagonistic soil bacteria.

PubMed

de Boer, Wietse; Wagenaar, Anne-Marieke; Klein Gunnewiek, Paulien J A; van Veen, Johannes A

2007-01-01

We hypothesized that apparently non-antagonistic soil bacteria may contribute to suppression of fungi during competitive interactions with other bacteria. Four soil bacteria (Brevundimonas sp., Luteibacter sp., Pedobacter sp. and Pseudomonas sp.) that exhibited little or no visible antifungal activity on different agar media were prescribed. Single and mixed strains of these species were tested for antagonism on a nutrient-poor agar medium against the plant pathogenic fungi Fusarium culmorum and Rhizoctonia solani and the saprotrophic fungus Trichoderma harzianum. Single bacterial strains caused little to moderate growth reduction of fungi (quantified as ergosterol), most probably due to nutrient withdrawal from the media. Growth reduction of fungi by the bacterial mixture was much stronger than that by the single strains. This appeared to be mostly due to competitive interactions between the Pseudomonas and Pedobacter strains. We argue that cohabitation of these strains triggered antibiotic production via interspecific interactions and that the growth reduction of fungi was a side-effect caused by the sensitivity of the fungi to bacterial secondary metabolites. Induction of gliding behavior in the Pedobacter strain by other strains was also observed. Our results indicate that apparently non-antagonistic soil bacteria may be important contributors to soil suppressiveness and fungistasis when in a community context.

Pseudomonas sp. BUP6 produces a thermotolerant alkaline lipase with trans-esterification efficiency in producing biodiesel.

PubMed

Priji, Prakasan; Sajith, Sreedharan; Faisal, Panichikkal Abdul; Benjamin, Sailas

2017-12-01

The present study describes the characteristics of a thermotolerant and alkaline lipase secreted by Pseudomonas sp. BUP6, a novel rumen bacterium isolated from Malabari goat, and its trans -esterification efficiency in producing biodiesel from used cooking oil (UCO). The extracellular lipase was purified to homogeneity (35.8 times purified with 14.8% yield) employing (NH 4 ) 2 SO 4 salt precipitation and Sephadex G-100 chromatography. The apparent molecular weight of this lipase on SDS-PAGE was 35 kDa, the identity of which was further confirmed by MALDI-TOF/MS. The purified lipase was found stable at a pH range of 7-9 with the maximum activity (707 U/ml) at pH 8.2; and was active at the temperature ranging from 35 to 50 °C with the optimum at 45 °C (891 U/ml). Triton X-100 and EDTA had no effect on the activity of lipase; whereas SDS, Tween-80 and β-mercaptoethanol inhibited its activity significantly. Moreover, Ca 2+ (1.0 mM) enhanced the activity of lipase (1428 U/ml) by 206% vis-à-vis initial activity; while Zn 2+ , Fe 2+ and Cu 2+ decreased the activity significantly. Using para -nitrophenyl palmitate as substrate, the K m (11.6 mM) and V max [668.9 μmol/(min/mg)] of the purified lipase were also determined. Crude lipase was used for analyzing its trans -esterification efficiency with used cooking oil and methanol which resulted in the worthy yield of fatty acid methyl esters, FAME (45%) at 37 °C, indicating its prospects in biodiesel industry. Thus, the lipase secreted by the rumen bacterium, Pseudomonas sp. BUP6, offers great potentials to be used in various industries including the production of biodiesel by trans -esterification.

Bacteria-mediated arsenic oxidation and reduction in the growth media of arsenic hyperaccumulator Pteris vittata.

PubMed

Wang, Xin; Rathinasabapathi, Bala; de Oliveira, Letuzia Maria; Guilherme, Luiz R G; Ma, Lena Q

2012-10-16

Microbes play an important role in arsenic transformation and cycling in the environment. Microbial arsenic oxidation and reduction were demonstrated in the growth media of arsenic hyperaccumulator Pteris vittata L. All arsenite (AsIII) at 0.1 mM in the media was oxidized after 48 h incubation. Oxidation was largely inhibited by antibiotics, indicating that bacteria played a dominant role. To identify AsIII oxidizing bacteria, degenerate primers were used to amplify ∼500 bp of the AsIII oxidase gene aioA (aroA) using DNA extracted from the media. One aioA (aroA)-like sequence (MG-1, tentatively identified as Acinetobacter sp.) was amplified, exhibiting 82% and 91% identity in terms of gene and deduced protein sequence to those from Acinetobacter sp. 33. In addition, four bacterial strains with different arsenic tolerance were isolated and identified as Comamonas sp.C-1, Flavobacterium sp. C-2, Staphylococcus sp. C-3, and Pseudomonas sp. C-4 using carbon utilization, fatty acid profiles, and/or sequencing 16s rRNA gene. These isolates exhibited dual capacity for both AsV reduction and AsIII oxidation under ambient conditions. Arsenic-resistant bacteria with strong AsIII oxidizing ability may have potential to improve bioremediation of AsIII-contaminated water using P. vittata and/or other biochemical strategies.

Biodegradation of phenanthrene in bioaugmented microcosm by consortium ASP developed from coastal sediment of Alang-Sosiya ship breaking yard.

PubMed

Patel, Vilas; Patel, Janki; Madamwar, Datta

2013-09-15

A phenanthrene-degrading bacterial consortium (ASP) was developed using sediment from the Alang-Sosiya shipbreaking yard at Gujarat, India. 16S rRNA gene-based molecular analyses revealed that the bacterial consortium consisted of six bacterial strains: Bacillus sp. ASP1, Pseudomonas sp. ASP2, Stenotrophomonas maltophilia strain ASP3, Staphylococcus sp. ASP4, Geobacillus sp. ASP5 and Alcaligenes sp. ASP6. The consortium was able to degrade 300 ppm of phenanthrene and 1000 ppm of naphthalene within 120 h and 48 h, respectively. Tween 80 showed a positive effect on phenanthrene degradation. The consortium was able to consume maximum phenanthrene at the rate of 46 mg/h/l and degrade phenanthrene in the presence of other petroleum hydrocarbons. A microcosm study was conducted to test the consortium's bioremediation potential. Phenanthrene degradation increased from 61% to 94% in sediment bioaugmented with the consortium. Simultaneously, bacterial counts and dehydrogenase activities also increased in the bioaugmented sediment. These results suggest that microbial consortium bioaugmentation may be a promising technology for bioremediation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Increased concentration of Pseudomonas aeruginosa and Staphylococcus sp. in small animals exposed to aerospace environments

NASA Technical Reports Server (NTRS)

Guthrie, R. K.

1976-01-01

The effects of increased concentrations of PSEUDOMONAS AERUGINOSA AND STAPHYLOCOCCUS in the total bacterial flora of small animals exposed to simulated spacecraft environments were evaluated. Tests to detect changes in infectivity, effects of antibiotic treatments, immune responses to bacterial antigens, and effectiveness of immune responses in the experimental environment were conducted. The most significant results appear to be the differences in immune responses at simulated altitudes and the production of infection in the presence of a specific antibody.

Dissolution of Arsenic Minerals Mediated by Dissimilatory Arsenate Reducing Bacteria: Estimation of the Physiological Potential for Arsenic Mobilization

PubMed Central

Lukasz, Drewniak; Liwia, Rajpert; Aleksandra, Mantur; Aleksandra, Sklodowska

2014-01-01

The aim of this study was characterization of the isolated dissimilatory arsenate reducing bacteria in the context of their potential for arsenic removal from primary arsenic minerals through reductive dissolution. Four strains, Shewanella sp. OM1, Pseudomonas sp. OM2, Aeromonas sp. OM4, and Serratia sp. OM17, capable of anaerobic growth with As (V) reduction, were isolated from microbial mats from an ancient gold mine. All of the isolated strains: (i) produced siderophores that promote dissolution of minerals, (ii) were resistant to dissolved arsenic compounds, (iii) were able to use the dissolved arsenates as the terminal electron acceptor, and (iii) were able to use copper minerals containing arsenic minerals (e.g., enargite) as a respiratory substrate. Based on the results obtained in this study, we postulate that arsenic can be released from some As-bearing polymetallic minerals (such as copper ore concentrates or middlings) under reductive conditions by dissimilatory arsenate reducers in indirect processes. PMID:24724102

Dissolution of arsenic minerals mediated by dissimilatory arsenate reducing bacteria: estimation of the physiological potential for arsenic mobilization.

PubMed

Lukasz, Drewniak; Liwia, Rajpert; Aleksandra, Mantur; Aleksandra, Sklodowska

2014-01-01

The aim of this study was characterization of the isolated dissimilatory arsenate reducing bacteria in the context of their potential for arsenic removal from primary arsenic minerals through reductive dissolution. Four strains, Shewanella sp. OM1, Pseudomonas sp. OM2, Aeromonas sp. OM4, and Serratia sp. OM17, capable of anaerobic growth with As (V) reduction, were isolated from microbial mats from an ancient gold mine. All of the isolated strains: (i) produced siderophores that promote dissolution of minerals, (ii) were resistant to dissolved arsenic compounds, (iii) were able to use the dissolved arsenates as the terminal electron acceptor, and (iii) were able to use copper minerals containing arsenic minerals (e.g., enargite) as a respiratory substrate. Based on the results obtained in this study, we postulate that arsenic can be released from some As-bearing polymetallic minerals (such as copper ore concentrates or middlings) under reductive conditions by dissimilatory arsenate reducers in indirect processes.

An unexplored pathway for degradation of cholate requires a 7α-hydroxysteroid dehydratase and contributes to a broad metabolic repertoire for the utilization of bile salts in Novosphingobium sp. strain Chol11.

PubMed

Yücel, Onur; Drees, Steffen; Jagmann, Nina; Patschkowski, Thomas; Philipp, Bodo

2016-12-01

Bile salts such as cholate are surface-active steroid compounds with functions for digestion and signaling in vertebrates. Upon excretion into soil and water bile salts are an electron- and carbon-rich growth substrate for environmental bacteria. Degradation of bile salts proceeds via intermediates with a 3-keto-Δ 1,4 -diene structure of the steroid skeleton as shown for e.g. Pseudomonas spp. Recently, we isolated bacteria degrading cholate via intermediates with a 3-keto-7-deoxy-Δ 4,6 -structure of the steroid skeleton suggesting the existence of a second pathway for cholate degradation. This potential new pathway was investigated with Novosphingobium sp. strain Chol11. A 7α-hydroxysteroid dehydratase encoded by hsh2 was identified, which was required for the formation of 3-keto-7-deoxy-Δ 4,6 -metabolites. A hsh2 deletion mutant could still grow with cholate but showed impaired growth. Cholate degradation of this mutant proceeded via 3-keto-Δ 1,4 -diene metabolites. Heterologous expression of Hsh2 in the bile salt-degrading Pseudomonas sp. strain Chol1 led to the formation of a dead-end steroid with a 3-keto-7-deoxy-Δ 4,6 -diene structure. Hsh2 is the first steroid dehydratase with an important function in a metabolic pathway of bacteria that use bile salts as growth substrates. This pathway contributes to a broad metabolic repertoire of Novosphingobium strain Chol11 that may be advantageous in competition with other bile salt-degrading bacteria. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Development of a real-time TaqMan assay to detect mendocina sublineage Pseudomonas species in contaminated metalworking fluids.

PubMed

Saha, Ratul; Donofrio, Robert S; Bagley, Susan T

2010-08-01

A TaqMan quantitative real-time polymerase chain reaction (qPCR) assay was developed for the detection and enumeration of three Pseudomonas species belonging to the mendocina sublineage (P. oleovorans, P. pseudoalcaligenes, and P. oleovorans subsp. lubricantis) found in contaminated metalworking fluids (MWFs). These microbes are the primary colonizers and serve as indicator organisms of biodegradation of used MWFs. Molecular techniques such as qPCR are preferred for the detection of these microbes since they grow poorly on typical growth media such as R2A agar and Pseudomonas isolation agar (PIA). Traditional culturing techniques not only underestimate the actual distribution of these bacteria but are also time-consuming. The primer-probe pair developed from gyrase B (gyrB) sequences of the targeted bacteria was highly sensitive and specific for the three species. qPCR was performed with both whole cell and genomic DNA to confirm the specificity and sensitivity of the assay. The sensitivity of the assay was 10(1) colony forming units (CFU)/ml for whole cell and 13.7 fg with genomic DNA. The primer-probe pair was successful in determining concentrations from used MWF samples, indicating levels between 2.9 x 10(3) and 3.9 x 10(6) CFU/ml. In contrast, the total count of Pseudomonas sp. recovered on PIA was in the range of <1.0 x 10(1) to 1.4 x 10(5) CFU/ml for the same samples. Based on these results from the qPCR assay, the designed TaqMan primer-probe pair can be efficiently used for rapid (within 2 h) determination of the distribution of these species of Pseudomonas in contaminated MWFs.

In vitro and in vivo evaluation of a new nanocomposite, containing high density polyethylene, tricalcium phosphate, hydroxyapatite, and magnesium oxide nanoparticles.

PubMed

Pourdanesh, Fereydoun; Jebali, Ali; Hekmatimoghaddam, Seyedhossein; Allaveisie, Azra

2014-07-01

In this study, a new nanocomposite, which contained high density polyethylene (HDPE), tricalcium phosphate (Ca3(PO4)2) nanoparticles (TCP NPs), hydroxyapatite nanoparticles (HA NPs), and magnesium oxide nanoparticles (MgO NPs) was prepared. As in vitro experiment, human osteoblasts (HOB) cells were exposed to pristine HDPE and its nanocomposite for a period of 1, 4, and 7 days at 37 °C, and then different assays were carried out, including osteoblast cell proliferation, Trypan blue staining, cell viability, alkaline phosphatase (ALP), and cell adhesion. Antibacterial property of pristine HDPE and its nanocomposite was evaluated, and also their mechanical properties were measured after 2 and 4 months. As in vivo experiment, pristine HDPE and its nanocomposite were separately implanted on calvarium bone of rabbits, and tissue inflammation and osteogenesis were investigated after 2, 4, and 6 months. In case of HOB cells treated with HDPE or nanocomposite, as incubation time was increased, cell proliferation, live/dead ratio, and cell viability were decreased. But, the ALP activity and cell adhesion of HOB cells which treated with nanocomposite were raised after increase of incubation time. This study demonstrated that although the mechanical properties of nanocomposite were similar to HDPE sheet, but their antibacterial property was not similar. The in vivo experiment showed that both pristine HDPE and its nanocomposite had same inflammation responses. Interestingly, osteogenesis was observed after 2 months at bone/nanocomposite interface, and was highly increased after 4 and 6 months. It must be noted that such pattern was not seen at bone/HDPE interface. Copyright © 2014 Elsevier B.V. All rights reserved.

Researching into the cellular shape, volume and elasticity of mesenchymal stem cells, osteoblasts and osteosarcoma cells by atomic force microscopy

PubMed Central

Docheva, Denitsa; Padula, Daniela; Popov, Cvetan; Mutschler, Wolf; Clausen-Schaumann, Hauke; Schieker, Matthias

2008-01-01

Abstract Within the bone lie several different cell types, including osteoblasts (OBs) and mesenchymal stem cells (MSCs). The MSCs are ideal targets for regenerative medicine of bone due to their differentiation potential towards OBs. Human MSCs exhibit two distinct morphologies: rapidly self-renewing cells (RS) and flat cells (FC) with very low proliferation rates. Another cell type found in pathological bone conditions is osteosarcoma. In this study, we compared the topographic and morphometric features of RS and FC cells, human OBs and MG63 osteosarcoma cells by atomic force microscopy (AFM). The results demonstrated clear differences: FC and hOB cells showed similar ruffled topography, whereas RS and MG63 cells exhibited smoother surfaces. Furthermore, we investigated how selected substrates influence cell morphometry. We found that RS and MG63 cells were flatter on fibrous substrates such as polystyrene and collagen I, but much more rounded on glass, the smoothest surface. In contrast, cells with large area, namely FC and hOB cells, did not exhibit pronounced changes in flatness with regards to the different substrates. They were, however, remarkably flatter in comparison to RS and MG63 cells. We could explain the differences in flatness by the extent of adhesion. Indeed, FC and hOB cells showed much higher content of focal adhesions. Finally, we used the AFM to determine the cellular Young's modulus. RS, FC and hOB cells showed comparable stiffness on the three different substrates, while MG63 cells demonstrated the unique feature of increased elasticity on collagen I. In summary, our results show, for the first time, a direct comparison between the morphometric and biophysical features of different human cell types derived from normal and pathological bone. Our study manifests the opinion that along with RNA, proteomic and functional research, morphological and biomechanical characterization of cells also reveals novel cell features and interrelationships. PMID:18419596

Thin magnesium layer confirmed as an antibacterial and biocompatible implant coating in a co‑culture model.

PubMed

Zaatreh, Sarah; Haffner, David; Strauss, Madlen; Dauben, Thomas; Zamponi, Christiane; Mittelmeier, Wolfram; Quandt, Eckhard; Kreikemeyer, Bernd; Bader, Rainer

2017-04-01

Implant-associated infections commonly result from biofilm‑forming bacteria and present severe complications in total joint arthroplasty. Therefore, there is a requirement for the development of biocompatible implant surfaces that prevent bacterial biofilm formation. The present study coated titanium samples with a thin, rapidly corroding layer of magnesium, which were subsequently investigated with respect to their antibacterial and cytotoxic surface properties using a Staphylococcus epidermidis (S. epidermidis) and human osteoblast (hOB) co‑culture model. Primary hOBs and S. epidermidis were co‑cultured on cylindrical titanium samples (Ti6Al4V) coated with pure magnesium via magnetron sputtering (5 µm thickness) for 7 days. Uncoated titanium test samples served as controls. Vital hOBs were identified by trypan blue staining at days 2 and 7. Planktonic S. epidermidis were quantified by counting the number of colony forming units (CFU). The quantification of biofilm‑bound S. epidermidis on the surfaces of test samples was performed by ultrasonic treatment and CFU counting at days 2 and 7. The number of planktonic and biofilm‑bound S. epidermidis on the magnesium‑coated samples decreased by four orders of magnitude when compared with the titanium control following 7 days of co‑culture. The number of vital hOBs on the magnesium‑coated samples was observed to increase (40,000 cells/ml) when compared with the controls (20,000 cells/ml). The results of the present study indicate that rapidly corroding magnesium‑coated titanium may be a viable coating material that possesses antibacterial and biocompatible properties. A co‑culture test is more rigorous than a monoculture study, as it accounts for confounding effects and assesses additional interactions that are more representative of in vivo situations. These results provide a foundation for the future testing of this type of surface in animals.

Thin magnesium layer confirmed as an antibacterial and biocompatible implant coating in a co-culture model

PubMed Central

Zaatreh, Sarah; Haffner, David; Strauss, Madlen; Dauben, Thomas; Zamponi, Christiane; Mittelmeier, Wolfram; Quandt, Eckhard; Kreikemeyer, Bernd; Bader, Rainer

2017-01-01

Implant-associated infections commonly result from biofilm-forming bacteria and present severe complications in total joint arthroplasty. Therefore, there is a requirement for the development of biocompatible implant surfaces that prevent bacterial biofilm formation. The present study coated titanium samples with a thin, rapidly corroding layer of magnesium, which were subsequently investigated with respect to their antibacterial and cytotoxic surface properties using a Staphylococcus epidermidis (S. epidermidis) and human osteoblast (hOB) co-culture model. Primary hOBs and S. epidermidis were co-cultured on cylindrical titanium samples (Ti6Al4V) coated with pure magnesium via magnetron sputtering (5 µm thickness) for 7 days. Uncoated titanium test samples served as controls. Vital hOBs were identified by trypan blue staining at days 2 and 7. Planktonic S. epidermidis were quantified by counting the number of colony forming units (CFU). The quantification of biofilm-bound S. epidermidis on the surfaces of test samples was performed by ultrasonic treatment and CFU counting at days 2 and 7. The number of planktonic and biofilm-bound S. epidermidis on the magnesium-coated samples decreased by four orders of magnitude when compared with the titanium control following 7 days of co-culture. The number of vital hOBs on the magnesium-coated samples was observed to increase (40,000 cells/ml) when compared with the controls (20,000 cells/ml). The results of the present study indicate that rapidly corroding magnesium-coated titanium may be a viable coating material that possesses antibacterial and biocompatible properties. A co-culture test is more rigorous than a monoculture study, as it accounts for confounding effects and assesses additional interactions that are more representative of in vivo situations. These results provide a foundation for the future testing of this type of surface in animals. PMID:28260022

Influence of high glucose and advanced glycation end-products (ages) levels in human osteoblast-like cells gene expression.

PubMed

Miranda, Cristina; Giner, Mercè; Montoya, M José; Vázquez, M Angeles; Miranda, M José; Pérez-Cano, Ramón

2016-08-31

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of osteoporotic fracture. Several factors have been identified as being potentially responsible for this risk, such as alterations in bone remodelling that may have been induced by changes in circulating glucose or/and by the presence of non-oxidative end products of glycosylation (AGEs). The aim of this study is to assess whether such variations generate a change in the gene expression related to the differentiation and osteoblast activity (OPG, RANKL, RUNX2, OSTERIX, and AGE receptor) in primary cultures of human osteoblast-like cells (hOB). We recruited 32 patients; 10 patients had osteoporotic hip fractures (OP group), 12 patients had osteoporotic hip fractures with T2DM (T2DM group), and 10 patients had hip osteoarthritis (OA group) with no osteoporotic fractures and no T2DM. The gene expression was analyzed in hOB cultures treated with physiological glucose concentration (4.5 mM) as control, high glucose (25 mM), and high glucose plus AGEs (2 μg/ml) for 24 h. The hOB cultures from patients with hip fractures presented slower proliferation. Additionally, the hOB cultures from the T2DM group were the most negatively affected with respect to RUNX2 and OSX gene expression when treated solely with high glucose or with high glucose plus AGEs. Moreover, high levels of glucose induced a major decrease in the RANKL/OPG ratio when comparing the OP and the T2DM groups to the OA group. Our data indicates an altered bone remodelling rate in the T2DM group, which may, at least partially, explain the reduced bone strength and increased incidence of non-traumatic fractures in diabetic patients.

Olivine-respiring bacteria isolated from the rock-ice interface in a lava-tube cave, a Mars analog environment.

PubMed

Popa, Radu; Smith, Amy R; Popa, Rodica; Boone, Jane; Fisk, Martin

2012-01-01

The boundary between ice and basalt on Earth is an analogue for some near-surface environments of Mars. We investigated neutrophilic iron-oxidizing microorganisms from the basalt-ice interface in a lava tube from the Oregon Cascades with perennial ice. One of the isolates (Pseudomonas sp. HerB) can use ferrous iron Fe(II) from the igneous mineral olivine as an electron donor and O(2) as an electron acceptor. The optimum growth temperature is ∼12-14°C, but growth also occurs at 5°C. Bicarbonate is a facultative source of carbon. Growth of Pseudomonas sp. HerB as a chemolithotrophic iron oxidizer with olivine as the source of energy is favored in low O(2) conditions (e.g., 1.6% O(2)). Most likely, microbial oxidation of olivine near pH 7 requires low O(2) to offset the abiotic oxidation of iron. The metabolic capabilities of this bacterium would allow it to live in near-surface, icy, volcanic environments of Mars in the present or recent geological past and make this type of physiology a prime candidate in the search for life on Mars.

Immobilization of Pseudomonas sp. DG17 onto sodium alginate–attapulgite–calcium carbonate

PubMed Central

Wang, Hong Qi; Hua, Fei; Zhao, Yi Cun; Li, Yi; Wang, Xuan

2014-01-01

A strain of Pseudomonas sp. DG17, capable of degrading crude oil, was immobilized in sodium alginate–attapulgite–calcium carbonate for biodegradation of crude oil contaminated soil. In this work, proportion of independent variables, the laboratory immobilization parameters, the micromorphology and internal structure of the immobilized granule, as well as the crude oil biodegradation by sodium alginate–attapulgite–calcium carbonate immobilized cells and sodium alginate–attapulgite immobilized cells were studied to build the optimal immobilization carrier and granule-forming method. The results showed that the optimal concentrations of sodium alginate–attapulgite–calcium carbonate and calcium chloride were 2.5%–3.5%, 0.5%–1%, 3%–7% and 2%–4%, respectively. Meanwhile, the optimal bath temperature, embedding cell amount, reaction time and multiplication time were 50–60 °C, 2%, 18 h and 48 h, respectively. Moreover, biodegradation was enhanced by immobilized cells with a total petroleum hydrocarbon removal ranging from 33.56% ± 3.84% to 56.82% ± 3.26% after 20 days. The SEM results indicated that adding calcium carbonate was helpful to form internal honeycomb-like pores in the immobilized granules. PMID:26019567

Polycyclic aromatic hydrocarbon degradation by biosurfactant-producing Pseudomonas sp. IR1.

PubMed

Kumara, Manoj; Leon, Vladimir; De Sisto Materano, Angela; Ilzins, Olaf A; Galindo-Castro, Ivan; Fuenmayor, Sergio L

2006-01-01

We characterized a newly isolated bacterium, designated as IR1, with respect to its ability to degrade polycyclic aromatic hydrocarbons (PAHs) and to produce biosurfactants. Isolated IR1 was identified as Pseudomonas putida by analysis of 16S rRNA sequences (99.6% homology). It was capable of utilizing two-, three- and four-ring PAHs but not hexadecane and octadecane as a sole carbon and energy source. PCR and DNA hybridization studies showed that enzymes involved in PAH metabolism were related to the naphthalene dioxygenase pathway. Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by IR1 during growth on both water miscible and immiscible substrates. The biosurfactants lowered the surface tension of medium from 54.9 dN cm(-1) to 35.4 dN cm(-1) and formed a stable and compact emulsion with an emulsifying activity of 74% with diesel oil, when grown on dextrose. These findings indicate that this isolate may be useful for bioremediation of sites contaminated with aromatic hydrocarbons.

Rhamnolipid influences biosorption and biodegradation of phenanthrene by phenanthrene-degrading strain Pseudomonas sp. Ph6.

PubMed

Ma, Zhao; Liu, Juan; Dick, Richard P; Li, Hui; Shen, Di; Gao, Yanzheng; Waigi, Michael Gatheru; Ling, Wanting

2018-05-08

Given the sub-lethal risks of synthetic surfactants, rhamnolipid is a promising class of biosurfactants with the potential to promote the bioavailability of polycyclic aromatic hydrocarbons (PAHs), to provide a favorable substitute for synthetic surfactants. However, few previous studies have integrated the behavior and mechanism behind rhamnolipid-influenced PAH biosorption and biodegradation. This is, to our knowledge, the first report of a bacterial envelope regulated link between phenanthrene (PHE) biosorption and biodegradation by rhamnolipid-induced PHE-degrading strain Pseudomonas sp. Ph6. Rhamnolipid (0─400 mg L -1 ) can change the cell-surface zeta potential, cell surface hydrophobicity (CSH), cell ultra-microstructure and functional groups, and then alter PHE biosorption and biodegradation of Ph6. Greater amounts of PHE sorbed on cell envelopes results in more PHE diffusing into cytochylema, thus favoring PHE intracellular biodegradation of Ph6. Rhamnolipid (≤100 mg L -1 ) could change the microstructures and functional groups of cell envelopes of Ph6, enhance the cell-surface zeta potential and CSH, thus consequently favor PHE biosorption and biodegradation by strain Ph6. By contrast, rhamnolipid at higher concentrations (≥200 mg L -1 ) hindered PHE biosorption and biodegradation. Rhamnolipid, as a biosurfactant, can be successfully utilized as an additive to improve the microbial biodegradation of PAHs in the environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

In-Situ Anaerobic Biosurfactant Production Process For Remediation Of DNAPL Contamination In Subsurface Aquifers

NASA Astrophysics Data System (ADS)

Albino, J. D.; Nambi, I. M.

2009-12-01

Microbial Enhanced Oil Recovery (MEOR) and remediation of aquifers contaminated with hydrophobic contaminants require insitu production of biosurfactants for mobilization of entrapped hydrophobic liquids. Most of the biosurfactant producing microorganisms produce them under aerobic condition and hence surfactant production is limited in subsurface condition due to lack of oxygen. Currently bioremediation involves expensive air sparging or excavation followed by exsitu biodegradation. Use of microorganisms which can produce biosurfactants under anaerobic conditions can cost effectively expedite the process of insitu bioremediation or mobilization. In this work, the feasibility of anaerobic biosurfactant production in three mixed anaerobic cultures prepared from groundwater and soil contaminated with chlorinated compounds and municipal sewage sludge was investigated. The cultures were previously enriched under complete anaerobic conditions in the presence of Tetrachloroethylene (PCE) for more than a year before they were studied for biosurfactant production. Biosurfactant production under anaerobic conditions was simulated using two methods: i) induction of starvation in the microbial cultures and ii) addition of complex fermentable substrates. Positive result for biosurfactant production was not observed when the cultures were induced with starvation by adding PCE as blobs which served as the only terminal electron acceptor. However, slight reduction in interfacial tension was noticed which was caused by the adherence of microbes to water-PCE interface. Biosurfactant production was observed in all the three cultures when they were fed with complex fermentable substrates and surface tension of the liquid medium was lowered below 35 mN/m. Among the fermentable substrates tested, vegetable oil yielded highest amount of biosurfactant in all the cultures. Complete biodegradation of PCE to ethylene at a faster rate was also observed when vegetable oil was amended to the microbial cultures. The microorganisms responsible for biosurfactant production was isolated and identified as Pseudomonas Sp (designated as Pseudomonas Sp ANBIOSURF-1, Gene bank no: FJ930079), Pseudomonas stutzeri (MTCC 10033), Pseudomonas Sp (MTCC 10032) from groundwater, soil and municipal sewage sludge enrichments respectively. This study confirms that biosurfactants can be produced under anaerobic conditions and also in sufficient quantities. The cultures were also able to cometabolically degrade PCE to Ethylene. The isolated microorganisms can be used for remediation of DNAPL contaminated sites by in-situ biosurfactant production.

Isolation and characterization of novel bacterial strains exhibiting ligninolytic potential

PubMed Central

2011-01-01

Background To expand on the range of products which can be obtained from lignocellulosic biomass, the lignin component should be utilized as feedstock for value-added chemicals such as substituted aromatics, instead of being incinerated for heat and energy. Enzymes could provide an effective means for lignin depolymerization into products of interest. In this study, soil bacteria were isolated by enrichment on Kraft lignin and evaluated for their ligninolytic potential as a source of novel enzymes for waste lignin valorization. Results Based on 16S rRNA gene sequencing and phenotypic characterization, the organisms were identified as Pandoraea norimbergensis LD001, Pseudomonas sp LD002 and Bacillus sp LD003. The ligninolytic capability of each of these isolates was assessed by growth on high-molecular weight and low-molecular weight lignin fractions, utilization of lignin-associated aromatic monomers and degradation of ligninolytic indicator dyes. Pandoraea norimbergensis LD001 and Pseudomonas sp. LD002 exhibited best growth on lignin fractions, but limited dye-decolourizing capacity. Bacillus sp. LD003, however, showed least efficient growth on lignin fractions but extensive dye-decolourizing capacity, with a particular preference for the recalcitrant phenothiazine dye class (Azure B, Methylene Blue and Toluidene Blue O). Conclusions Bacillus sp. LD003 was selected as a promising source of novel types of ligninolytic enzymes. Our observations suggested that lignin mineralization and depolymerization are separate events which place additional challenges on the screening of ligninolytic microorganisms for specific ligninolytic enzymes. PMID:21995752

Cultivable endophytic bacteria from leaf bases of Agave tequilana and their role as plant growth promoters

PubMed Central

Martínez-Rodríguez, Julia del C.; la Mora-Amutio, Marcela De; Plascencia-Correa, Luis A.; Audelo-Regalado, Esmeralda; Guardado, Francisco R.; Hernández-Sánchez, Elías; Peña-Ramírez, Yuri J.; Escalante, Adelfo; Beltrán-García, Miguel J.; Ogura, Tetsuya

2014-01-01

Agave tequilana Weber var. ‘Azul’ is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost. PMID:25763038

Cultivable endophytic bacteria from leaf bases of Agave tequilana and their role as plant growth promoters.

PubMed

Martínez-Rodríguez, Julia del C; De la Mora-Amutio, Marcela; Plascencia-Correa, Luis A; Audelo-Regalado, Esmeralda; Guardado, Francisco R; Hernández-Sánchez, Elías; Peña-Ramírez, Yuri J; Escalante, Adelfo; Beltrán-García, Miguel J; Ogura, Tetsuya

2014-01-01

Agave tequilana Weber var. 'Azul' is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost.

Functional consortium for denitrifying sulfide removal process.

PubMed

Chen, Chuan; Ren, Nanqi; Wang, Aijie; Liu, Lihong; Lee, Duu-Jong

2010-03-01

Denitrifying sulfide removal (DSR) process simultaneously converts sulfide, nitrate, and chemical oxygen demand from industrial wastewaters to elemental sulfur, nitrogen gas, and carbon dioxide, respectively. This investigation utilizes a dilution-to-extinction approach at 10(-2) to 10(-6) dilutions to elucidate the correlation between the composition of the microbial community and the DSR performance. In the original suspension and in 10(-2) dilution, the strains Stenotrophomonas sp., Thauera sp., and Azoarcus sp. are the heterotrophic denitrifiers and the strains Paracoccus sp. and Pseudomonas sp. are the sulfide-oxidizing denitrifers. The 10(-4) dilution is identified as the functional consortium for the present DSR system, which comprises two functional strains, Stenotrophomonas sp. strain Paracoccus sp. At 10(-6) dilution, all DSR performance was lost. The functions of the constituent cells in the DSR granules were discussed based on data obtained using the dilution-to-extinction approach.

Structure and activity of lobophorins from a turrid mollusk-associated Streptomyces sp.

PubMed

Lin, Zhenjian; Koch, Michael; Pond, Christopher D; Mabeza, Gaiselle; Seronay, Romell A; Concepcion, Gisela P; Barrows, Louis R; Olivera, Baldomero M; Schmidt, Eric W

2014-01-01

A novel lumun-lumun sampling methodology was used to obtain a large diversity of micromollusks, including the new species Lienardia totopotens. In turn, from L. totopotens we cultivated a Streptomyces sp. strain that contained new and known spirotetronate polyketides, lobophorins (1-5). The structures were elucidated using spectroscopy, and the compounds were evaluated for cytotoxicity to human cells and activity against Mycobacterium tuberculosis, Bacillus subtilis, Pseudomonas aeruginosa and Burkholderia cepacia. Compounds 2-5 showed varying degrees of activity against human cells, M. tuberculosis and B. subtilis in the low μM to mid nM range but were inactive against the other strains, while 1 lacking digitoxose was inactive. Very slight structural changes in 2-5 led to varying antibacterial:cytotoxicity ratios, providing a possible basis to synthesize more selective derivatives.

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

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

Differentiating Pseudomonas sp. strain ADP cells in suspensions and biofilms using Raman spectroscopy and scanning electron microscopy.

PubMed

Henry, Victoria A; Jessop, Julie L P; Peeples, Tonya L

2017-02-01

High quality spectra of Pseudomonas sp. strain ADP in the planktonic and biofilm state were obtained using Raman microspectroscopy. These spectra enabled the identification of key differences between free and biofilm cells in the fingerprint region of Raman spectra in the nucleic acid, carbohydrate, and protein regions. Scanning electron microscopy (SEM) enabled detailed visualization of ADP biofilm with confirmation of associated extracellular matrix structure. Following extraction and Raman analysis of extracellular polymeric substances, Raman spectral differences between free and biofilm cells were largely attributed to the contribution of extracellular matrix components produced in mature biofilms. Raman spectroscopy complemented with SEM proves to be useful in distinguishing physiological properties among cells of the same species. Graphical Abstract Raman spectroscopy complemented with SEM proves to be useful in distinguishing physiological properties among cells of the same species.

The effect of mulching and soil compaction on fungi composition and microbial communities in the rhizosphere of soybean

NASA Astrophysics Data System (ADS)

Frac, M.; Siczek, A.; Lipiec, J.

2009-04-01

The soil environment is the habitat of pathogenic and saprotrophic microorganisms. The composition of the microbial community are related to biotic and abiotic factors, such as root exudates, crop residues, climate factors, mulching, mineral fertilization, pesticides introduction and soil compaction. The aim of the study was to determine the effect of the mulching and soil compaction on the microorganism communities in the rhizosphere soil of soybean. The studies were carried out on silty loam soil (Orthic Luvisol) developed from loess (Lublin, Poland). The experiment area was 192m2 divided into 3 sections consisted of 6 micro-plots (7m2). Three levels of soil compaction low, medium and heavy obtained through tractor passes were compared. The soil was compacted and loosened within seedbed layer 2 weeks before sowing. Soybean "Aldana" seeds were inoculated with Bradyrhizobium japonicum and were sown with interrow spacing of 0.3m. Wheat straw (as mulch) was uniformly spread on the half of each micro-plot at an amount of 0.5kg m-1 after sowing. Rhizosphere was collected three times during growing season of soybean. Microbiological analyses were conducted in 3 replications and included the determination of: the total number of bacteria and fungi, the number of bacteria Pseudomonas sp. and Bacillus sp., the genus identification of fungi isolated from rhizosphere of soybean. Results indicated a positive effect of mulching on the increase number of all groups of examined rhizosphere microorganisms (fungi, bacteria, Pseudomonas sp., Bacillus sp.). The highest number of the microorganisms was found in the low and medium compacted soil and markedly decreased in the most compacted soil. Relatively high number of antagonistic fungi (Penicillium sp., Trichoderma sp.) was recorded in the rhizosphere of low and medium compacted soil, particularly in mulched plots. The presence of these fungi can testify to considerable biological activity, which contributes to the improvement of the phytosanitary condition of the soil. However, the decrease of the antagonistic microorganism number in the heavy compacted soil can be responsible for appearance higher number of the potentially phytopathogenic fungi (Fusarium sp., Phoma sp.). Further research, with using molecular technique, will help better understanding interactions between plant and microorganisms in the soybean rhizosphere under different soil management conditions.

[Growth and photochemical efficiency of photosystem ii in seedlings of two varieties of Capsicum annuum L. inoculated with rhizobacteria and arbuscular mycorrhizal fungi].

PubMed

Angulo-Castro, Azareel; Ferrera-Cerrato, Ronald; Alarcón, Alejandro; Almaraz-Suárez, Juan José; Delgadillo-Martínez, Julián; Jiménez-Fernández, Maribel; García-Barradas, Oscar

Plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) are a biological alternative for the sustainable management of Capsicum annuum L. This research work evaluated the effects of both PGPR and AMF on bell pepper and jalapeno pepper plants. Five bacterial strains isolated from several locations in Estado de Mexico were used: [P61 (Pseudomonas tolaasii), A46 (P. tolaasii), R44 (Bacillus pumilus), BSP1.1 (Paenibacillus sp.), and OLs-Sf5 (Pseudomonas sp.)], and three treatments with AMF [H1 (consortium isolated from pepper crops in the State of Puebla), H2 (Rhizophagus intraradices), and H3 (consortium isolated from the rhizosphere of lemon trees, State of Tabasco)]. In addition, a fertilized treatment (Steiner nutrient solution at 25%) and an unfertilized control were included. Seedlings of "Caloro" jalapeno pepper and "California Wonder" bell pepper were inoculated with AMF at seed sowing, and PGPR were inoculated after 15 days of seedling emergence; seedlings were grown under plant growth chamber conditions. P61 bacterium and H1 AMF consortia were the most effective microorganisms for jalapeno pepper whereas R44 bacterium and AMF H3 and H1 were the most effective for bell peppers, when compared to the unfertilized control. Furthermore, P61 and R44 bacteria showed beneficial effects on PSII efficiency. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Air purification from a mixture VOCs in the pilot-scale trickle-bed bioreactor (TBB)

NASA Astrophysics Data System (ADS)

Sarzyński, Rafał; Gąszczak, Agnieszka; Janecki, Daniel; Bartelmus, Grażyna

2017-10-01

The efficiency of the air bio-purification from the mixture of two volatile organic compounds (styrene and p-xylene) was studied. The process was carried out in a pilot-scale trickle-bed bioreactor installation designed to purify ˜200 m3h-1 of the polluted air. The bioreactor operated at concurrent flow of gas and liquid (mineral salt solution) through packing (polypropylene Ralu rings) covered with a thin layer of microorganisms (bacterial consortium of Pseudomonas sp. E-022150 and Pseudomonas putida mt-2). The experiments, carried out for various values of a reactor load with pollutant, confirmed the great efficiency of the investigated process. At the tested bed load with pollution (inlet specific pollutant load was changed within the range of 41 - 84 gm-3 h -1), styrene conversion degree changed within the range of 80-87% and p-xylene conversion degree within the range of 42-48%.

Isolation of a gene (pbsC) required for siderophore biosynthesis in fluorescent Pseudomonas sp. strain M114.

PubMed

Adams, C; Dowling, D N; O'Sullivan, D J; O'Gara, F

1994-06-03

An iron-regulated gene, pbsC, required for siderophore production in fluorescent Pseudomonas sp. strain M114 has been identified. A kanamycin-resistance cassette was inserted at specific restriction sites within a 7 kb genomic fragment of M114 DNA and by marker exchange two siderophore-negative mutants, designated M1 and M2, were isolated. The nucleotide sequence of approximately 4 kb of the region flanking the insertion sites was determined and a large open reading frame (ORF) extending for 2409 bp was identified. This gene was designated pbsC (pseudobactin synthesis C) and its putative protein product termed PbsC. PbsC was found to be homologous to a family of enzymes involved in the biosynthesis of secondary metabolites, including EntF of Escherichia coli. These enzymes are believed to act via ATP-dependent binding of AMP to their substrate. Several areas of high sequence homology between these proteins and PbsC were observed, including a conserved AMP-binding domain. The expression of pbsC is iron-regulated as revealed when a DNA fragment containing the upstream region was cloned in a promoter probe vector and conjugated into the wild-type strain, M114. The nucleotide sequence upstream of the putative translational start site contains a region homologous to previously defined -16 to -25 sequences of iron-regulated genes but did not contain an iron-box consensus sequence. It was noted that inactivation of the pbsC gene also affected other iron-regulated phenotypes of Pseudomonas M114.

Isolation of bacterial strains able to degrade biphenyl, diphenyl ether and the heat transfer fluid used in thermo-solar plants.

PubMed

Blanco-Moreno, Rafael; Sáez, Lara P; Luque-Almagro, Víctor M; Roldán, M Dolores; Moreno-Vivián, Conrado

2017-03-25

Thermo-solar plants use eutectic mixtures of diphenyl ether (DE) and biphenyl (BP) as heat transfer fluid (HTF). Potential losses of HTF may contaminate soils and bioremediation is an attractive tool for its treatment. DE- or BP-degrading bacteria are known, but up to now bacteria able to degrade HTF mixture have not been described. Here, five bacterial strains which are able to grow with HTF or its separate components DE and BP as sole carbon sources have been isolated, either from soils exposed to HTF or from rhizospheric soils of plants growing near a thermo-solar plant. The organisms were identified by 16S rRNA gene sequencing as Achromobacter piechaudii strain BioC1, Pseudomonas plecoglossicida strain 6.1, Pseudomonas aeruginosa strains HBD1 and HBD3, and Pseudomonas oleovorans strain HBD2. Activity of 2,3-dihydroxybiphenyl dioxygenase (BphC), a key enzyme of the biphenyl upper degradation pathway, was detected in all isolates. Pseudomonas strains almost completely degraded 2000ppm HTF after 5-day culture, and even tolerated and grew in the presence of 150,000ppm HTF, being suitable candidates for in situ soil bioremediation. Degradation of both components of HTF is of particular interest since in the DE-degrader Sphingomonas sp. SS3, growth on DE or benzoate was strongly inhibited by addition of BP. Copyright © 2016 Elsevier B.V. All rights reserved.

Biodegradation of p-nitrophenol via 1,2,4-benzenetriol by an Arthrobacter sp.

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

Jain, R.K.; Spain, J.C.; Dreisbach, J.H.

1994-08-01

The degradation of p-nitrophenol (PNP) by Moraxella and Pseudomonas spp. involves an initial monooxygenase-catalyzed removal of the nitro group. The resultant hydroquinone is subject to ring fission catalyzed by a dioxygenase enzyme. A strain of an Arthrobacter sp. JS443, capable of degrading PNP with stoichiometric release of nitrite has been isolated. During induction of the enzymes required for growth on PNP, 1,2,4-benzenetriol was identified as an intermediate by gas chromatography-mass spectroscopy and radiotracer studies. 1,2,4-Benzenetriol was converted to maleylacetic acid, which was further degraded by the beta-ketoadipate pathway. Conversion of PNP to 1,2,4-benzenetriol is catalyzed by a monooxygenase system inmore » strain JS443 through the formation of 4-nitrocatechol, 4-nitroresorcinol, or both. Results clearly indicate the existence of an alternative pathway for the biodegradation of PNP. 15 refs, 2 figs., 2 tabs.« less

Chemical composition of essential oil from ripe fruit of Schinus terebinthifolius Raddi and evaluation of its activity against wild strains of hospital origin

PubMed Central

Cole, E.R.; dos Santos, R.B.; Júnior, V. Lacerda; Martins, J.D.L.; Greco, S.J.; Neto, A. Cunha

2014-01-01

The essential oil (EO) composition of ripe fruit of S. terebinthifolius Raddi was analyzed by GC-MS. The oil extraction yielded 6.54 ± 1.06% (w/w). Seventeen compounds were identified, accounting for 91.15% of the total oil, where monoterpenes constituted the main chemical class (85.81%), followed by sesquiterpenes (5.34%). The major monoterpene identified was δ-3-carene (30.37%), followed by limonene (17.44%), α-phellandrene (12.60%) and α-pinene (12.59%). Trans-caryophyllene (1.77%) was the major sesquiterpene identified. The antibacterial activity of the essential oil was evaluated against wild strains of hospital origin (Escherichia coli, Pseudomonas sp., Klebsiella oxytoca, Corynebacterium sp., Staphylococcus aureus, Enterobacter sp., Enterobacter agglomerans, Bacillus sp., Nocardia sp. and Streptococcus group D). The essential oil of the ripe fruit of S. terebinthifolius Raddi has shown to be active against all tested wild strains, with minimum inhibitory concentration ranging from 3.55 μg/mL to 56.86 μg/mL. However, it has revealed some differences in susceptibility: the general, Gram-positive species showed greater sensitivity to the action of EO, which is probably due to the lower structural complexity of their cell walls. PMID:25477913

Chemical composition of essential oil from ripe fruit of Schinus terebinthifolius Raddi and evaluation of its activity against wild strains of hospital origin.

PubMed

Cole, E R; dos Santos, R B; Lacerda Júnior, V; Martins, J D L; Greco, S J; Cunha Neto, A

2014-01-01

The essential oil (EO) composition of ripe fruit of S. terebinthifolius Raddi was analyzed by GC-MS. The oil extraction yielded 6.54 ± 1.06% (w/w). Seventeen compounds were identified, accounting for 91.15% of the total oil, where monoterpenes constituted the main chemical class (85.81%), followed by sesquiterpenes (5.34%). The major monoterpene identified was δ-3-carene (30.37%), followed by limonene (17.44%), α-phellandrene (12.60%) and α-pinene (12.59%). Trans-caryophyllene (1.77%) was the major sesquiterpene identified. The antibacterial activity of the essential oil was evaluated against wild strains of hospital origin (Escherichia coli, Pseudomonas sp., Klebsiella oxytoca, Corynebacterium sp., Staphylococcus aureus, Enterobacter sp., Enterobacter agglomerans, Bacillus sp., Nocardia sp. and Streptococcus group D). The essential oil of the ripe fruit of S. terebinthifolius Raddi has shown to be active against all tested wild strains, with minimum inhibitory concentration ranging from 3.55 μg/mL to 56.86 μg/mL. However, it has revealed some differences in susceptibility: the general, Gram-positive species showed greater sensitivity to the action of EO, which is probably due to the lower structural complexity of their cell walls.

Changes in bacterial resistance patterns in children with urinary tract infections on antimicrobial prophylaxis at University Hospital in Split

PubMed Central

Ilić, Tanja; Gračan, Sanda; Arapović, Adela; Čapkun, Vesna; Šubat-Dežulović, Mirna; Saraga, Marijan

2011-01-01

Summary Background We assessed prevalence and resistance of uropathogens on antimicrobial agents (AA) from urine cultures (UC) in children hospitalized with urinary tract infections (UTI) at University Hospital in Split. Material/Methods During the 7-year period, children hospitalized only once with UTI alone were compared to those repeatedly hospitalized, and who received long-term antimicrobial prophylaxis (LTAP), as well as those with associated anomalies of the urinary system (US). Results E. coli was the most frequent isolate (67.7%) with resistance to ampicillin by 69.5%, amoxicillin/clavulonic acid by 3.5%, cephalexin by 6.6%, trimethoprim/sulfamethoxazole (TMP-SMX) by 27.5%, and nitrofurantoin by 0.4%. For other uropathogens, AA resistance rates were the following: 64.3%, 5.8%, 10.5%, 21.3%, and 7.9%. The high or increasing resistance to TMP-SMX is characterized by all uropathogens. Patients with anomalies of US showed a lower prevalence of E. coli and Enterococcus sp., but a higher prevalence of Pseudomonas sp., ESBL-producing E. coli and Klebsiella sp. than those without US anomalies. Repeatedly hospitalized patients showed a lower prevalence of E. coli, but a higher prevalence of Pseudomonas sp. and Klebsiella sp. than patients hospitalized only once. Both groups displayed significantly less resistance of Enterococcus sp. In patients receiving LTAP before hospitalization, E. coli was significantly more resistant to ampicillin, amoxicillin/clavulonic acid and TMP/SMX than in those without LTAP. Conclusions Based on our results, we recommend excluding ampicillin altogether, and reconsideration of further use of TMP-SMX, as well as use of nitrofurantoin, cephalexin and amoxicillin/clavulonic acid for LTAP in our region. PMID:21709628

Potential of wheat bran to promote indigenous microbial enhanced oil recovery.

PubMed

Zhan, Yali; Wang, Qinghong; Chen, Chunmao; Kim, Jung Bong; Zhang, Hongdan; Yoza, Brandon A; Li, Qing X

2017-06-01

Microbial enhanced oil recovery (MEOR) is an emerging oil extraction technology that utilizes microorganisms to facilitate recovery of crude oil in depleted petroleum reservoirs. In the present study, effects of wheat bran utilization were investigated on stimulation of indigenous MEOR. Biostimulation conditions were optimized with the response surface methodology. The co-application of wheat bran with KNO 3 and NH 4 H 2 PO 4 significantly promoted indigenous MEOR (IMEOR) and exhibited sequential aerobic (O-), facultative (A n -) and anaerobic (A 0 -) metabolic stages. The surface tension of fermented broth decreased by approximately 35%, and the crude oil was highly emulsified. Microbial community structure varied largely among and in different IMEOR metabolic stages. Pseudomonas sp., Citrobacter sp., and uncultured Burkholderia sp. dominated the O-, A n - and early A 0 -stages. Bacillus sp., Achromobacter sp., Rhizobiales sp., Alcaligenes sp. and Clostridium sp. dominated the later A 0 -stage. This study illustrated occurrences of microbial community succession driven by wheat bran stimulation and its industrial potential.

The fate of arsenic adsorbed on iron oxides in the presence of arsenite-oxidizing bacteria.

PubMed

Zhang, Zhennan; Yin, Naiyi; Du, Huili; Cai, Xiaolin; Cui, Yanshan

2016-05-01

Arsenic (As) is a redox-active metalloid whose toxicity and mobility in soil depend on its oxidation state. Arsenite [As(III)] can be oxidized by microbes and adsorbed by minerals in the soil. However, the combined effects of these abiotic and biotic processes are not well understood. In this study, the fate of arsenic in the presence of an isolated As(III)-oxidizing bacterium (Pseudomonas sp. HN-1, 10(9) colony-forming units (CFUs)·ml(-1)) and three iron oxides (goethite, hematite, and magnetite at 1.6 g L(-1)) was determined using batch experiments. The total As adsorption by iron oxides was lower with bacteria present and was higher with iron oxides alone. The total As adsorption decreased by 78.6%, 36.0% and 79.7% for goethite, hematite and magnetite, respectively, due to the presence of bacteria. As(III) adsorbed on iron oxides could also be oxidized by Pseudomonas sp. HN-1, but the oxidation rate (1.3 μmol h(-1)) was much slower than the rate in the aqueous phase (96.2 μmol h(-1)). Therefore, the results of other studies with minerals only might overestimate the adsorptive capacity of solids in natural systems; the presence of minerals might hinder As(III) oxidation by microbes. Under aerobic conditions, in the presence of iron oxides and As(III)-oxidizing bacteria, arsenic is adsorbed onto iron oxides within the adsorption capacity, and As(V) is the primary form in the solid and aqueous phases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative effectiveness of Pseudomonas and Serratia sp. containing ACC-deaminase for improving growth and yield of wheat (Triticum aestivum L.) under salt-stressed conditions.

PubMed

Zahir, Zahir Ahmad; Ghani, Usman; Naveed, Muhammad; Nadeem, Sajid Mahmood; Asghar, Hafiz Naeem

2009-05-01

Ethylene synthesis is accelerated in response to various environmental stresses like salinity. Ten rhizobacterial strains isolated from wheat rhizosphere taken from different salt affected areas were screened for growth promotion of wheat under axenic conditions at 1, 5, 10 and 15 dS m(-1). Three strains, i.e., Pseudomonas putida (N21), Pseudomonas aeruginosa (N39) and Serratia proteamaculans (M35) showing promising performance under axenic conditions were selected for a pot trial at 1.63 (original), 5, 10 and 15 dS m(-1). Results showed that inoculation was effective even in the presence of higher salinity levels. P. putida was the most efficient strain compared to the other strains and significantly increased the plant height, root length, grain yield, 100-grain weight and straw yield up to 52, 60, 76, 19 and 67%, respectively, over uninoculated control at 15 dS m(-1). Similarly, chlorophyll content and K(+)/Na(+) of leaves also increased by P. putida over control. It is highly likely that under salinity stress, 1-aminocyclopropane-1-carboxylic acid-deaminase activity of these microbial strains might have caused reduction in the synthesis of stress (salt)-induced inhibitory levels of ethylene. The results suggested that these strains could be employed for salinity tolerance in wheat; however, P. putida may have better prospects in stress alleviation/reduction.

[State of Fungal Lipases of Rhizopus microsporus, Penicillium sp. and Oospora lactis in Border Layers Water-Solid Phase and Factors Affecting Catalytic Properties of Enzymes].

PubMed

Khasanov, Kh T; Davranov, K; Rakhimov, M M

2015-01-01

We demonstrated that a change in the catalytic activity of fungal lipases synthesized by Rhizopus microsporus, Penicillium sp. and Oospora lactis and their ability to absorb on different sorbents depended on the nature of groups on the solid phase surface in the model systems water: lipid and water: solid phase. Thus, the stability of Penicillium sp. lipases increased 85% in the presence ofsorsilen or DEAE-cellulose, and 55% of their initial activity respectively was preserved. In the presence of silica gel and CM-cellulose, a decreased rate of lipid hydrolysis by Pseudomonas sp. enzymes was observed in water medium, and the hydrolysis rate increased by 2.4 and 1.5 times respectively in the presence of aminoaerosil and polykefamid. In an aqueous-alcohol medium, aminoaerosil and polykefamid decreased the rate of substrate hydrolysis by more than 30 times. The addition of aerosil to aqueous and aqueous-alcohol media resulted in an increase in the hydrolysis rate by 1.2-1.3 times. Sorsilen stabilized Penicillium sp. lipase activity at 40, 45, 50 and 55 degrees C. Either stabilization or inactivation of lipases was observed depending on the pH of the medium and the nature of chemical groups localized on the surface of solid phase. The synthetizing activity of lipases also changed depending on the conditions.

Biotransformation of geosmin by terpene-degrading bacteria.

USDA-ARS?s Scientific Manuscript database

Two terpene-degrading bacteria that are able to transform geosmin have been identified. Pseudomonas sp. SBR3-tpnb, isolated on -terpinene, converts geosmin to several products; the major products are keto-geosmins. This geosmin transformation ability is inducible by -terpinene. Rhodococcus wratisl...

Adding Selectivity to Antimicrobial Peptides: Rational Design of a Multidomain Peptide against Pseudomonas spp.

PubMed Central

Eckert, Randal; Qi, Fengxia; Yarbrough, Daniel K.; He, Jian; Anderson, Maxwell H.; Shi, Wenyuan

2006-01-01

Currently available antimicrobials exhibit broad killing with regard to bacterial genera and species. Indiscriminate killing of microbes by these conventional antibiotics can disrupt the ecological balance of the indigenous microbial flora, often resulting in negative clinical consequences. Species-specific antimicrobials capable of precisely targeting pathogenic bacteria without damaging benign microorganisms provide a means of avoiding this problem. In this communication, we report the successful creation of the first synthetic, target-specific antimicrobial peptide, G10KHc, via addition of a rationally designed Pseudomonas-specific targeting moiety (KH) to a generally killing peptide (novispirin G10). The resulting chimeric peptide showed enhanced bactericidal activity and faster killing kinetics against Pseudomonas spp. than G10 alone. The enhanced killing activities are due to increased binding and penetration of the outer membrane of Pseudomonas sp. cells. These properties were not observed in tests of untargeted bacterial species, and this specificity allowed G10KHc to selectively eliminate Pseudomonas spp. from mixed cultures. This work lays a foundation for generating target-specific “smart” antimicrobials to complement currently available conventional antibiotics. PMID:16569868

Diversity of endophytic Pseudomonas in Halimione portulacoides from metal(loid)-polluted salt marshes.

PubMed

Rocha, Jaqueline; Tacão, Marta; Fidalgo, Cátia; Alves, Artur; Henriques, Isabel

2016-07-01

Phytoremediation assisted by bacteria is seen as a promising alternative to reduce metal contamination in the environment. The main goal of this study was to characterize endophytic Pseudomonas isolated from Halimione portulacoides, a metal-accumulator plant, in salt marshes contaminated with metal(loid)s. Phylogenetic analysis based on 16S rRNA and gyrB genes showed that isolates affiliated with P. sabulinigri (n = 16), P. koreensis (n = 10), P. simiae (n = 5), P. seleniipraecipitans (n = 2), P. guineae (n = 2), P. migulae (n = 1), P. fragi (n = 1), P. xanthomarina (n = 1), and Pseudomonas sp. (n = 1). Most of these species have never been described as endophytic. The majority of the isolates were resistant to three or more metal(loid)s. Antibiotic resistance was frequent among the isolates but most likely related to species-intrinsic features. Common acquired antibiotic resistance genes and integrons were not detected. Plasmids were detected in 43.6 % of the isolates. Isolates that affiliated with different species shared the same plasmid profile but attempts to transfer metal resistance to receptor strains were not successful. Phosphate solubilization and IAA production were the most prevalent plant growth promoting traits, and 20 % of the isolates showed activity against phytopathogenic bacteria. Most isolates produced four or more extracellular enzymes. Preliminary results showed that two selected isolates promote Arabidopsis thaliana root elongation. Results highlight the diversity of endophytic Pseudomonas in H. portulacoides from contaminated sites and their potential to assist phytoremediation by acting as plant growth promoters and as environmental detoxifiers.

No apparent costs for facultative antibiotic production by the soil bacterium Pseudomonas fluorescens Pf0-1.

PubMed

Garbeva, Paolina; Tyc, Olaf; Remus-Emsermann, Mitja N P; van der Wal, Annemieke; Vos, Michiel; Silby, Mark; de Boer, Wietse

2011-01-01

Many soil-inhabiting bacteria are known to produce secondary metabolites that can suppress microorganisms competing for the same resources. The production of antimicrobial compounds is expected to incur fitness costs for the producing bacteria. Such costs form the basis for models on the co-existence of antibiotic-producing and non-antibiotic producing strains. However, so far studies quantifying the costs of antibiotic production by bacteria are scarce. The current study reports on possible costs, for antibiotic production by Pseudomonas fluorescens Pf0-1, a soil bacterium that is induced to produce a broad-spectrum antibiotic when it is confronted with non-related bacterial competitors or supernatants of their cultures. We measured the possible cost of antibiotic production for Pseudomonas fluorescens Pf0-1 by monitoring changes in growth rate with and without induction of antibiotic production by supernatant of a bacterial competitor, namely Pedobacter sp.. Experiments were performed in liquid as well as on semi-solid media under nutrient-limited conditions that are expected to most clearly reveal fitness costs. Our results did not reveal any significant costs for production of antibiotics by Pseudomonas fluorescens Pf0-1. Comparison of growth rates of the antibiotic-producing wild-type cells with those of non-antibiotic producing mutants did not reveal costs of antibiotic production either. Based on our findings we propose that the facultative production of antibiotics might not be selected to mitigate metabolic costs, but instead might be advantageous because it limits the risk of competitors evolving resistance, or even the risk of competitors feeding on the compounds produced.

Structural determination of the acidic exopolysaccharide produced by a Pseudomonas sp. strain 1.15.

PubMed

Cescutti, P; Toffanin, R; Pollesello, P; Sutherland, I W

1999-01-31

Pseudomonas strain 1.15 was isolated from a freshwater biofilm and shown to produce considerable amounts of an acidic polysaccharide which was investigated by methylation analysis, NMR spectroscopy and ionspray mass spectrometry (ISMS). The polysaccharide was depolymerised by a bacteriophage-associated endoglucosidase and by autohydrolysis, and the resulting oligosaccharides were investigated by NMR spectroscopy and mass spectrometry. The resulting data showed that the parent repeating unit of the 1.15 exopolysaccharide (EPS) is a branched hexasaccharide. The main chain is constituted of the trisaccharide -->4)-alpha-L-Fucp-(1-->4)-alpha-L-Fucp-(1-->3)-beta-D-Glcp- (1--> and the side chain alpha-D-Galp-(1-->4)-beta-D-GlcAp-(1-->3)-alpha-D-Galp-(1-->is linked to O-3 of the first Fuc residue. The terminal non-reducing Gal carries a 1-carboxyethylidene acetal in the R configuration at the positions 4 and 6. Of the four different O-acetyl groups present in non-stoichiometric amounts, two were established to be on O-2 of the 3-linked Gal and on O-2 of the 4-linked Fuc.

Function of a Glutamine Synthetase-Like Protein in Bacterial Aniline Oxidation via γ-Glutamylanilide

PubMed Central

Ohara, Akira; Sakae, Shinji; Okamoto, Yasuhiro; Kitamura, Chitoshi; Kato, Dai-ichiro; Negoro, Seiji

2013-01-01

Acinetobacter sp. strain YAA has five genes (atdA1 to atdA5) involved in aniline oxidation as a part of the aniline degradation gene cluster. From sequence analysis, the five genes were expected to encode a glutamine synthetase (GS)-like protein (AtdA1), a glutamine amidotransferase-like protein (AtdA2), and an aromatic compound dioxygenase (AtdA3, AtdA4, and AtdA5) (M. Takeo, T. Fujii, and Y. Maeda, J. Ferment. Bioeng. 85:17-24, 1998). A recombinant Pseudomonas strain harboring these five genes quantitatively converted aniline into catechol, demonstrating that catechol is the major oxidation product from aniline. To elucidate the function of the GS-like protein AtdA1 in aniline oxidation, we purified it from recombinant Escherichia coli harboring atdA1. The purified AtdA1 protein produced gamma-glutamylanilide (γ-GA) quantitatively from aniline and l-glutamate in the presence of ATP and MgCl2. This reaction was identical to glutamine synthesis by GS, except for the use of aniline instead of ammonia as the substrate. Recombinant Pseudomonas strains harboring the dioxygenase genes (atdA3 to atdA5) were unable to degrade aniline but converted γ-GA into catechol, indicating that γ-GA is an intermediate to catechol and a direct substrate for the dioxygenase. Unexpectedly, a recombinant Pseudomonas strain harboring only atdA2 hydrolyzed γ-GA into aniline, reversing the γ-GA formation by AtdA1. Deletion of atdA2 from atdA1 to atdA5 caused γ-GA accumulation from aniline in recombinant Pseudomonas cells and inhibited the growth of a recombinant Acinetobacter strain on aniline, suggesting that AtdA2 prevents γ-GA accumulation that is harmful to the host cell. PMID:23893114

Function of a glutamine synthetase-like protein in bacterial aniline oxidation via γ-glutamylanilide.

PubMed

Takeo, Masahiro; Ohara, Akira; Sakae, Shinji; Okamoto, Yasuhiro; Kitamura, Chitoshi; Kato, Dai-ichiro; Negoro, Seiji

2013-10-01

Acinetobacter sp. strain YAA has five genes (atdA1 to atdA5) involved in aniline oxidation as a part of the aniline degradation gene cluster. From sequence analysis, the five genes were expected to encode a glutamine synthetase (GS)-like protein (AtdA1), a glutamine amidotransferase-like protein (AtdA2), and an aromatic compound dioxygenase (AtdA3, AtdA4, and AtdA5) (M. Takeo, T. Fujii, and Y. Maeda, J. Ferment. Bioeng. 85:17-24, 1998). A recombinant Pseudomonas strain harboring these five genes quantitatively converted aniline into catechol, demonstrating that catechol is the major oxidation product from aniline. To elucidate the function of the GS-like protein AtdA1 in aniline oxidation, we purified it from recombinant Escherichia coli harboring atdA1. The purified AtdA1 protein produced gamma-glutamylanilide (γ-GA) quantitatively from aniline and l-glutamate in the presence of ATP and MgCl2. This reaction was identical to glutamine synthesis by GS, except for the use of aniline instead of ammonia as the substrate. Recombinant Pseudomonas strains harboring the dioxygenase genes (atdA3 to atdA5) were unable to degrade aniline but converted γ-GA into catechol, indicating that γ-GA is an intermediate to catechol and a direct substrate for the dioxygenase. Unexpectedly, a recombinant Pseudomonas strain harboring only atdA2 hydrolyzed γ-GA into aniline, reversing the γ-GA formation by AtdA1. Deletion of atdA2 from atdA1 to atdA5 caused γ-GA accumulation from aniline in recombinant Pseudomonas cells and inhibited the growth of a recombinant Acinetobacter strain on aniline, suggesting that AtdA2 prevents γ-GA accumulation that is harmful to the host cell.

Computerized Modeling and Loaded Tooth Contact Analysis of Hypoid Gears Manufactured by Face Hobbing Process

NASA Astrophysics Data System (ADS)

Nishino, Takayuki

The face hobbing process has been widely applied in automotive industry. But so far few analytical tools have been developed. This makes it difficult for us to optimize gear design. To settle this situation, this study aims at developing a computerized tool to predict the running performances such as loaded tooth contact pattern, static transmission error and so on. First, based upon kinematical analysis of a cutting machine, a mathematical description of tooth surface generation is given. Second, based upon the theory of gearing and differential geometry, conjugate tooth surfaces are studied. Then contact lines are generated. Third, load distribution along contact lines is formulated. Last, the numerical model is validated by measuring loaded transmission error and loaded tooth contact pattern.

New Polyphenols from a Deep Sea Spiromastix sp. Fungus, and Their Antibacterial Activities

PubMed Central

Niu, Siwen; Liu, Dong; Proksch, Peter; Shao, Zongze; Lin, Wenhan

2015-01-01

Eleven new polyphenols namely spiromastols A–K (1–11) were isolated from the fermentation broth of a deep sea-derived fungus Spiromastix sp. MCCC 3A00308. Their structures were determined by extensive NMR data and mass spectroscopic analysis in association with chemical conversion. The structures are classified as diphenyl ethers, diphenyl esters and isocoumarin derivatives, while the n-propyl group in the analogues is rarely found in natural products. Compounds 1–3 exhibited potent inhibitory effects against a panel of bacterial strains, including Xanthomanes vesicatoria, Pseudomonas lachrymans, Agrobacterium tumefaciens, Ralstonia solanacearum, Bacillus thuringensis, Staphylococcus aureus and Bacillus subtilis, with minimal inhibitory concentration (MIC) values ranging from 0.25 to 4 µg/mL. The structure-activity relationships are discussed, while the polychlorinated analogues 1–3 are assumed to be a promising structural model for further development as antibacterial agents. PMID:25913707

Culturable Aerobic and Facultative Anaerobic Intestinal Bacterial Flora of Black Cobra (Naja naja karachiensis) in Southern Pakistan

PubMed Central

Iqbal, Junaid; Sagheer, Mehwish; Tabassum, Nazneen; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

2014-01-01

Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections. PMID:25002979

Implications in studies of environmental risk assessments: Does culture medium influence the results of toxicity tests of marine bacteria?

PubMed

Díaz-García, Alejandra; Borrero-Santiago, Ana R; Riba, Inmaculada

2018-04-14

Two marine bacterial populations (Roseobacter sp. and Pseudomonas litoralis) were exposed to different concentrations of zinc (300, 625, 1250, 2000, 2500 and 5000 mg L -1 ) and cadmium (75, 250, 340, 500 and 1000 mg L -1 ) using two culture media (full nutrient Marine Broth 2216 "MB" and 1:10 (vol/vol) dilution with seawater of Marine Broth 2216 "MB SW "), in order to assess population responses depending on the culture medium and also potential adverse effects associated with these two metals. Different responses were found depending on the culture medium (Bacterial abundance (cells·mL -1 ), growth rates (μ, hours -1 ), and production of Extracellular Polysaccharides Substances (EPS) (μg glucose·cells -1 ). Results showed negative effects in both strains after the exposure to Zn treatments. Both strains showed highest metal sensitivity at low concentrations using both culture media. However, different results were found when exposing the bacterial populations to Cd treatments depending on the culture medium. Highest toxicity was observed using MB at low levels of Cd concentrations, whereas MB SW showed toxicity to bacteria at higher concentrations of Cd. Results not only showed adverse effects on Roseobacter sp. and Pseudomonas litoralis associated with the concentration of Zn and Cd, but also confirm that depending on the culture medium results can differ. This work suggests MB SW as an adequate culture medium to study metal toxicity bioassays in order to predict realistic effects on marine bacterial populations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Antimicrobials from the marine algal endophyte Penicillium sp.

PubMed

Flewelling, Andrew J; Johnson, John A; Gray, Christopher A

2013-03-01

An endophytic fungus identified as Penicillium sp. was isolated from the brown alga Fucus spiralis collected from the Shetland Islands, United Kingdom. Bioassay-guided fractionation of an extract of the fungus led to the isolation of cladosporin, epiepoformin, phyllostine, and patulin, all of which showed antimicrobial activity against either Staphylococcus aureus or Pseudomonas aeruginosa. Cladosporin has not previously been identified from a fungus of the genus Penicillium, and, despite being biosynthetically related, epiepoformin, phyllostine and patulin have not been previously reported from one source.

Bacterial Conversion of Hydroxylamino Aromatic Compounds by both Lyase and Mutase Enzymes Involves Intramolecular Transfer of Hydroxyl Groups

PubMed Central

Nadeau, Lloyd J.; He, Zhongqi; Spain, Jim C.

2003-01-01

Hydroxylamino aromatic compounds are converted to either the corresponding aminophenols or protocatechuate during the bacterial degradation of nitroaromatic compounds. The origin of the hydroxyl group of the products could be the substrate itself (intramolecular transfer mechanism) or the solvent water (intermolecular transfer mechanism). The conversion of hydroxylaminobenzene to 2-aminophenol catalyzed by a mutase from Pseudomonas pseudoalcaligenes JS45 proceeds by an intramolecular hydroxyl transfer. The conversions of hydroxylaminobenzene to 2- and 4-aminophenol by a mutase from Ralstonia eutropha JMP134 and to 4-hydroxylaminobenzoate to protocatechuate by a lyase from Comamonas acidovorans NBA-10 and Pseudomonas sp. strain 4NT were proposed, but not experimentally proved, to proceed by the intermolecular transfer mechanism. GC-MS analysis of the reaction products formed in H218O did not indicate any 18O-label incorporation during the conversion of hydroxylaminobenzene to 2- and 4-aminophenols catalyzed by the mutase from R. eutropha JMP134. During the conversion of 4-hydroxylaminobenzoate catalyzed by the hydroxylaminolyase from Pseudomonas sp. strain 4NT, only one of the two hydroxyl groups in the product, protocatechuate, was 18O labeled. The other hydroxyl group in the product must have come from the substrate. The mutase in strain JS45 converted 4-hydroxylaminobenzoate to 4-amino-3-hydroxybenzoate, and the lyase in Pseudomonas strain 4NT converted hydroxylaminobenzene to aniline and 2-aminophenol but not to catechol. The results indicate that all three types of enzyme-catalyzed rearrangements of hydroxylamino aromatic compounds proceed via intramolecular transfer of hydroxyl groups. PMID:12732549

Atropine Metabolism by Pseudomonas sp. Strain AT3: Evidence for Nortropine as an Intermediate in Tropine Breakdown and Reactions Leading to Succinate.

PubMed

Bartholomew, B A; Smith, M J; Trudgill, P W; Hopper, D J

1996-09-01

Pseudomonas strain AT3, isolated by elective culture with atropine, hydrolyzed atropine and grew diauxically, first on the tropic acid and then on the tropine. Tropine was also used as a sole carbon and energy source. The methyl group of tropine was eliminated as formaldehyde, and the nortropine thus formed was a precursor of 6-hydroxycyclohepta-1,4-dione. Ammonia was detected as a product of nitrogen elimination. 6-Hydroxycyclohepta-1,4-dione was oxidized to cyclohepta-1,3,5-trione by an induced NAD(sup+)-specific dehydrogenase. Although cyclohepta-1,3,5-trione is a (beta)-diketone with two potential hydrolytic cleavage sites, an induced hydrolase was specific for one of these sites, with 4,6-dioxoheptanoate as the only hydrolysis product. Unlike the alternative cleavage product (3,6-dioxoheptanoate), this compound is also a (beta)-diketone, and a second hydrolytic cleavage formed succinate and acetone. Although Pseudomonas strain AT3 was not capable of growth with acetone, the compound was not detected in the culture medium and may have been lost to the atmosphere. Exhaustive experimentation with a wide range of conditions did not result in detection of the enzymes required for cleavage of the carbon-nitrogen bonds leading to the formation of nortropine and 6-hydroxycyclohepta-1,4-dione.

Atropine Metabolism by Pseudomonas sp. Strain AT3: Evidence for Nortropine as an Intermediate in Tropine Breakdown and Reactions Leading to Succinate

PubMed Central

Bartholomew, B. A.; Smith, M. J.; Trudgill, P. W.; Hopper, D. J.

1996-01-01

Pseudomonas strain AT3, isolated by elective culture with atropine, hydrolyzed atropine and grew diauxically, first on the tropic acid and then on the tropine. Tropine was also used as a sole carbon and energy source. The methyl group of tropine was eliminated as formaldehyde, and the nortropine thus formed was a precursor of 6-hydroxycyclohepta-1,4-dione. Ammonia was detected as a product of nitrogen elimination. 6-Hydroxycyclohepta-1,4-dione was oxidized to cyclohepta-1,3,5-trione by an induced NAD(sup+)-specific dehydrogenase. Although cyclohepta-1,3,5-trione is a (beta)-diketone with two potential hydrolytic cleavage sites, an induced hydrolase was specific for one of these sites, with 4,6-dioxoheptanoate as the only hydrolysis product. Unlike the alternative cleavage product (3,6-dioxoheptanoate), this compound is also a (beta)-diketone, and a second hydrolytic cleavage formed succinate and acetone. Although Pseudomonas strain AT3 was not capable of growth with acetone, the compound was not detected in the culture medium and may have been lost to the atmosphere. Exhaustive experimentation with a wide range of conditions did not result in detection of the enzymes required for cleavage of the carbon-nitrogen bonds leading to the formation of nortropine and 6-hydroxycyclohepta-1,4-dione. PMID:16535398

PSYCHROPHILIC PSEUDOMONAS SP. RESISTANT TO MERCURY FROM PAVLODAR, KAZAKHSTAN

EPA Science Inventory

As mercury circulates and deposits globally, the remediation of extensive mercury contamination surrounding a chloralkali plant in Pavlodar, Kazakhstan is critical. High-levels of mercury contamination exist within the confines of the plant, at nearby off-site waste storage and e...

Olivine-Respiring Bacteria Isolated from the Rock-Ice Interface in a Lava-Tube Cave, a Mars Analog Environment

PubMed Central

Smith, Amy R.; Popa, Rodica; Boone, Jane; Fisk, Martin

2012-01-01

Abstract The boundary between ice and basalt on Earth is an analogue for some near-surface environments of Mars. We investigated neutrophilic iron-oxidizing microorganisms from the basalt-ice interface in a lava tube from the Oregon Cascades with perennial ice. One of the isolates (Pseudomonas sp. HerB) can use ferrous iron Fe(II) from the igneous mineral olivine as an electron donor and O2 as an electron acceptor. The optimum growth temperature is ∼12–14°C, but growth also occurs at 5°C. Bicarbonate is a facultative source of carbon. Growth of Pseudomonas sp. HerB as a chemolithotrophic iron oxidizer with olivine as the source of energy is favored in low O2 conditions (e.g., 1.6% O2). Most likely, microbial oxidation of olivine near pH 7 requires low O2 to offset the abiotic oxidation of iron. The metabolic capabilities of this bacterium would allow it to live in near-surface, icy, volcanic environments of Mars in the present or recent geological past and make this type of physiology a prime candidate in the search for life on Mars. Key Words: Extremophiles—Mars—Olivine—Iron-oxidizing bacteria—Redox. Astrobiology 12, 9–18. PMID:22165996

Detection and characterization of broad-spectrum antipathogen activity of novel rhizobacterial isolates and suppression of Fusarium crown and root rot disease of tomato.

PubMed

Zhang, L; Khabbaz, S E; Wang, A; Li, H; Abbasi, P A

2015-03-01

To detect and characterize broad-spectrum antipathogen activity of indigenous bacterial isolates obtained from potato soil and soya bean leaves for their potential to be developed as biofungicides to control soilborne diseases such as Fusarium crown and root rot of tomato (FCRR) caused by Fusarium oxysporum f. sp. radicis-lycopersici (Forl). Thirteen bacterial isolates (Bacillus amyloliquefaciens (four isolates), Paenibacillus polymyxa (three isolates), Pseudomonas chlororaphis (two isolates), Pseudomonas fluorescens (two isolates), Bacillus subtilis (one isolate) and Pseudomonas sp. (one isolate)) or their volatiles showed antagonistic activity against most of the 10 plant pathogens in plate assays. Cell-free culture filtrates (CF) of five isolates or 1-butanol extracts of CFs also inhibited the growth of most pathogen mycelia in plate assays. PCR analysis confirmed the presence of most antibiotic biosynthetic genes such as phlD, phzFA, prnD and pltC in most Pseudomonas isolates and bmyB, bacA, ituD, srfAA and fenD in most Bacillus isolates. These bacterial isolates varied in the production of hydrogen cyanide (HCN), siderophores, β-1,3-glucanases, chitinases, proteases, indole-3-acetic acid, salicylic acid, and for nitrogen fixation and phosphate solubilization. Gas chromatography-mass spectrometry analysis identified 10 volatile compounds from 10 isolates and 18 compounds from 1-butanol extracts of CFs of five isolates. Application of irradiated peat formulation of six isolates to tomato roots prior to transplanting in a Forl-infested potting mix and field soil provided protection of tomato plants from FCRR disease and enhanced plant growth under greenhouse conditions. Five of the 13 indigenous bacterial isolates were antagonistic to eight plant pathogens, both in vitro and in vivo. Antagonistic and plant-growth promotion activities of these isolates might be related to the production of several types of antibiotics, lytic enzymes, phytohormones, secondary metabolites, siderophores and volatile compounds; however, any specific role of each needs to be determined. Indigenous antagonistic bacterial isolates have the potential to be developed as biofungicides for minimizing early crop losses due to soilborne diseases caused by Fusarium and other soilborne pathogens. © 2014 Her Majesty the Queen in Right of Canada © 2014 The Society for Applied Microbiology. Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

Light spectrum modifies the utilization pattern of energy sources in Pseudomonas sp. DR 5-09

PubMed Central

Rosberg, Anna Karin; Windstam, Sofia T.; Karlsson, Maria E.; Bergstrand, Karl-Johan; Khalil, Sammar; Wohanka, Walter

2017-01-01

Despite the overruling impact of light in the phyllosphere, little is known regarding the influence of light spectra on non-phototrophic bacteria colonizing the leaf surface. We developed an in vitro method to study phenotypic profile responses of bacterial pure cultures to different bands of the visible light spectrum using monochromatic (blue: 460 nm; red: 660 nm) and polychromatic (white: 350–990 nm) LEDs, by modification and optimization of a protocol for the Phenotype MicroArray™ technique (Biolog Inc., CA, USA). The new protocol revealed high reproducibility of substrate utilization under all conditions tested. Challenging the non-phototrophic bacterium Pseudomonas sp. DR 5–09 with white, blue, and red light demonstrated that all light treatments affected the respiratory profile differently, with blue LED having the most decisive impact on substrate utilization by impairing respiration of 140 substrates. The respiratory activity was decreased on 23 and 42 substrates under red and white LEDs, respectively, while utilization of one, 16, and 20 substrates increased in the presence of red, blue, and white LEDs, respectively. Interestingly, on four substrates contrasting utilization patterns were found when the bacterium was exposed to different light spectra. Although non-phototrophic bacteria do not rely directly on light as an energy source, Pseudomonas sp. DR 5–09 changed its respiratory activity on various substrates differently when exposed to different lights. Thus, ability to sense and distinguish between different wavelengths even within the visible light spectrum must exist, and leads to differential regulation of substrate usage. With these results, we hypothesize that different light spectra might be a hitherto neglected key stimulus for changes in microbial lifestyle and habits of substrate usage by non-phototrophic phyllospheric microbiota, and thus might essentially stratify leaf microbiota composition and diversity. PMID:29267321

Mercury (II) removal by resistant bacterial isolates and mercuric (II) reductase activity in a new strain of Pseudomonas sp. B50A.

PubMed

Giovanella, Patricia; Cabral, Lucélia; Bento, Fátima Menezes; Gianello, Clesio; Camargo, Flávio Anastácio Oliveira

2016-01-25

This study aimed to isolate mercury resistant bacteria, determine the minimum inhibitory concentration for Hg, estimate mercury removal by selected isolates, explore the mer genes, and detect and characterize the activity of the enzyme mercuric (II) reductase produced by a new strain of Pseudomonas sp. B50A. The Hg removal capacity of the isolates was determined by incubating the isolates in Luria Bertani broth and the remaining mercury quantified by atomic absorption spectrophotometry. A PCR reaction was carried out to detect the merA gene and the mercury (II) reductase activity was determined in a spectrophotometer at 340 nm. Eight Gram-negative bacterial isolates were resistant to high mercury concentrations and capable of removing mercury, and of these, five were positive for the gene merA. The isolate Pseudomonas sp. B50A removed 86% of the mercury present in the culture medium and was chosen for further analysis of its enzyme activity. Mercuric (II) reductase activity was detected in the crude extract of this strain. This enzyme showed optimal activity at pH 8 and at temperatures between 37 °C and 45 °C. The ions NH4(+), Ba(2+), Sn(2+), Ni(2+) and Cd(2+) neither inhibited nor stimulated the enzyme activity but it decreased in the presence of the ions Ca(2+), Cu(+) and K(+). The isolate and the enzyme detected were effective in reducing Hg(II) to Hg(0), showing the potential to develop bioremediation technologies and processes to clean-up the environment and waste contaminated with mercury. Copyright © 2015 Elsevier B.V. All rights reserved.

Light spectrum modifies the utilization pattern of energy sources in Pseudomonas sp. DR 5-09.

PubMed

Gharaie, Samareh; Vaas, Lea A I; Rosberg, Anna Karin; Windstam, Sofia T; Karlsson, Maria E; Bergstrand, Karl-Johan; Khalil, Sammar; Wohanka, Walter; Alsanius, Beatrix W

2017-01-01

Despite the overruling impact of light in the phyllosphere, little is known regarding the influence of light spectra on non-phototrophic bacteria colonizing the leaf surface. We developed an in vitro method to study phenotypic profile responses of bacterial pure cultures to different bands of the visible light spectrum using monochromatic (blue: 460 nm; red: 660 nm) and polychromatic (white: 350-990 nm) LEDs, by modification and optimization of a protocol for the Phenotype MicroArray™ technique (Biolog Inc., CA, USA). The new protocol revealed high reproducibility of substrate utilization under all conditions tested. Challenging the non-phototrophic bacterium Pseudomonas sp. DR 5-09 with white, blue, and red light demonstrated that all light treatments affected the respiratory profile differently, with blue LED having the most decisive impact on substrate utilization by impairing respiration of 140 substrates. The respiratory activity was decreased on 23 and 42 substrates under red and white LEDs, respectively, while utilization of one, 16, and 20 substrates increased in the presence of red, blue, and white LEDs, respectively. Interestingly, on four substrates contrasting utilization patterns were found when the bacterium was exposed to different light spectra. Although non-phototrophic bacteria do not rely directly on light as an energy source, Pseudomonas sp. DR 5-09 changed its respiratory activity on various substrates differently when exposed to different lights. Thus, ability to sense and distinguish between different wavelengths even within the visible light spectrum must exist, and leads to differential regulation of substrate usage. With these results, we hypothesize that different light spectra might be a hitherto neglected key stimulus for changes in microbial lifestyle and habits of substrate usage by non-phototrophic phyllospheric microbiota, and thus might essentially stratify leaf microbiota composition and diversity.

Pseudomonas gallaeciensis sp. nov., isolated from crude-oil-contaminated intertidal sand samples after the Prestige oil spill.

PubMed

Mulet, Magdalena; Sánchez, David; Rodríguez, Ana C; Nogales, Balbina; Bosch, Rafael; Busquets, Antonio; Gomila, Margarita; Lalucat, Jorge; García-Valdés, Elena

2018-04-11

Strains V113 T , V92 and V120 have been isolated from sand samples taken at the Atlantic intertidal shore in Galicia, Spain, after the Prestige oil spill. A preliminary analysis of the 16S rRNA and the partial rpoD gene sequences indicated that these strains belonged to the Pseudomonas genus, but they were distinct from any known Pseudomonas species. They were extensively characterized by a polyphasic taxonomic approach and phylogenetic data that confirmed that these strains belonged to the Pseudomonas pertucinogena group. Phylogenetic analysis of 16S rRNA, gyrB and rpoD gene sequences showed that the three strains were 99% similar and were closely related to members of the P. pertucinogena group, with less than 94% similarity to strains of established species; Pseudomonas pachastrellae was the closest relative. The Average Nucleotide Index based on blast values was 89.0% between V113 T and the P. pachastrellae type strain, below the accepted species level (95%). The predominant cellular fatty acid contents and whole cell protein profiles determined by MALDI-TOF mass spectrometry also differentiated the studied strains from known Pseudomonas species. We therefore conclude that strains V113 T , V92 and V120 represent a novel species of Pseudomonas, for which the name Pseudomonas gallaeciensis is proposed; the type strain is V113 T (=CCUG 67583 T =LMG 29038 T ). Copyright © 2018 Elsevier GmbH. All rights reserved.

Culture-Independent Analysis of Bacterial Fuel Contamination Provides Insight into the Level of Concordance with the Standard Industry Practice of Aerobic Cultivation ▿ †

PubMed Central

White, Judith; Gilbert, Jack; Hill, Graham; Hill, Edward; Huse, Susan M.; Weightman, Andrew J.; Mahenthiralingam, Eshwar

2011-01-01

Bacterial diversity in contaminated fuels has not been systematically investigated using cultivation-independent methods. The fuel industry relies on phenotypic cultivation-based contaminant identification, which may lack accuracy and neglect difficult-to-culture taxa. By the use of industry practice aerobic cultivation, 16S rRNA gene sequencing, and strain genotyping, a collection of 152 unique contaminant isolates from 54 fuel samples was assembled, and a dominance of Pseudomonas (21%), Burkholderia (7%), and Bacillus (7%) was demonstrated. Denaturing gradient gel electrophoresis (DGGE) of 15 samples revealed Proteobacteria and Firmicutes to be the most abundant phyla. When 16S rRNA V6 gene pyrosequencing of four selected fuel samples (indicated by “JW”) was performed, Betaproteobacteria (42.8%) and Gammaproteobacteria (30.6%) formed the largest proportion of reads; the most abundant genera were Marinobacter (15.4%; JW57), Achromobacter (41.6%; JW63), Burkholderia (80.7%; JW76), and Halomonas (66.2%; JW78), all of which were also observed by DGGE. However, the Clostridia (38.5%) and Deltaproteobacteria (11.1%) identified by pyrosequencing in sample JW57 were not observed by DGGE or aerobic culture. Genotyping revealed three instances where identical strains were found: (i) a Pseudomonas sp. strain recovered from 2 different diesel fuel tanks at a single industrial site; (ii) a Mangroveibacter sp. strain isolated from 3 biodiesel tanks at a single refinery site; and (iii) a Burkholderia vietnamiensis strain present in two unrelated automotive diesel samples. Overall, aerobic cultivation of fuel contaminants recovered isolates broadly representative of the phyla and classes present but lacked accuracy by overrepresenting members of certain groups such as Pseudomonas. PMID:21602386

Culture-independent analysis of bacterial fuel contamination provides insight into the level of concordance with the standard industry practice of aerobis cultivation.

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

White, J.; Gilbert, J. A.; Hill, G.

2011-07-01

Bacterial diversity in contaminated fuels has not been systematically investigated using cultivation-independent methods. The fuel industry relies on phenotypic cultivation-based contaminant identification, which may lack accuracy and neglect difficult-to-culture taxa. By the use of industry practice aerobic cultivation, 16S rRNA gene sequencing, and strain genotyping, a collection of 152 unique contaminant isolates from 54 fuel samples was assembled, and a dominance of Pseudomonas (21%), Burkholderia (7%), and Bacillus (7%) was demonstrated. Denaturing gradient gel electrophoresis (DGGE) of 15 samples revealed Proteobacteria and Firmicutes to be the most abundant phyla. When 16S rRNA V6 gene pyrosequencing of four selected fuel samplesmore » (indicated by 'JW') was performed, Betaproteobacteria (42.8%) and Gammaproteobacteria (30.6%) formed the largest proportion of reads; the most abundant genera were Marinobacter (15.4%; JW57), Achromobacter (41.6%; JW63), Burkholderia (80.7%; JW76), and Halomonas (66.2%; JW78), all of which were also observed by DGGE. However, the Clostridia (38.5%) and Deltaproteobacteria (11.1%) identified by pyrosequencing in sample JW57 were not observed by DGGE or aerobic culture. Genotyping revealed three instances where identical strains were found: (i) a Pseudomonas sp. strain recovered from 2 different diesel fuel tanks at a single industrial site; (ii) a Mangroveibacter sp. strain isolated from 3 biodiesel tanks at a single refinery site; and (iii) a Burkholderia vietnamiensis strain present in two unrelated automotive diesel samples. Overall, aerobic cultivation of fuel contaminants recovered isolates broadly representative of the phyla and classes present but lacked accuracy by overrepresenting members of certain groups such as Pseudomonas.« less

Molecular and Biochemical Characterization of the Natural Chromosome-Encoded Class A β-Lactamase from Pseudomonas luteola▿

PubMed Central

Doublet, Benoît; Robin, Frédéric; Casin, Isabelle; Fabre, Laëtitia; Le Fleche, Anne; Bonnet, Richard; Weill, François-Xavier

2010-01-01

Pseudomonas luteola (formerly classified as CDC group Ve-1 and named Chryseomonas luteola) is an unusual pathogen implicated in rare but serious infections in humans. A novel β-lactamase gene, blaLUT-1, was cloned from the whole-cell DNA of the P. luteola clinical isolate LAM, which had a weak narrow-spectrum β-lactam-resistant phenotype, and expressed in Escherichia coli. This gene encoded LUT-1, a 296-amino-acid Ambler class A β-lactamase with a pI of 6 and a theoretical molecular mass of 28.9 kDa. The catalytic efficiency of this enzyme was higher for cephalothin, cefuroxime, and cefotaxime than for penicillins. It was found to be 49% to 59% identical to other Ambler class A β-lactamases from Burkholderia sp. (PenA to PenL), Ralstonia eutropha (REUT), Citrobacter sedlakii (SED-1), Serratia fonticola (FONA and SFC-1), Klebsiella sp. (KPC and OXY), and CTX-M extended-spectrum β-lactamases. No gene homologous to the regulatory ampR genes of class A β-lactamases was found in the vicinity of the blaLUT-1 gene. The entire blaLUT-1 coding region was amplified by PCR and sequenced in five other genetically unrelated P. luteola strains (including the P. luteola type strain). A new variant of blaLUT-1 was found for each strain. These genes (named blaLUT-2 to blaLUT-6) had nucleotide sequences 98.1 to 99.5% identical to that of blaLUT-1 and differing from this gene by two to four nonsynonymous single nucleotide polymorphisms. The blaLUT gene was located on a 700- to 800-kb chromosomal I-CeuI fragment, the precise size of this fragment depending on the P. luteola strain. PMID:19884377

Toxicity of a New Polynitramine Energetic Material, CL-20, to the Enchytraeid Worm, Enchytraeus Crypticus, in a Sandy Loam Soil

DTIC Science & Technology

2006-08-01

transformation, and other fate processes that commonly occur at contaminated sites ( Kaplan , 1992; Gorontzy et al., 1994; Preuf and Rieger, 1995; Daun et al...CL-20) by denitrifying Pseudomonas sp. strain FA1 . Appl. Environ. Microbiol. 69, 5216-5221. Bhushan, B., Halasz, A., Hawari, J., 2004a...contamination at military firing ranges. Technical Report ERDC TR-01-5. USACE Engineer Research and Development Center, Vicksburg, MS. 26 Kaplan , D.L

Batch kinetics of Pseudomonas sp. growth on benzene. Modeling of product and substrate inhibitions.

PubMed

Monero, Alessandra; Lanza, Luca; Zilli, Mario; Sene, Luciane; Converti, Attilio

2003-01-01

Batch tests of benzene degradation were performed in liquid phase at 30 degrees C, pH 6.8 +/- 0.2, and 200 rpm in two 3-L stirred tank bioreactors, using the benzene-degrading bacterium Pseudomonas sp. NCIMB 9688. A relatively high starting biomass level (220-270 mg(X)/L) and starting benzene concentration ranging from 20 to 200 mg(S)/L were selected as conditions to investigate possible inhibition phenomena. Volumetric as well as specific rates of biomass formation and substrate consumption were calculated from experimental data of both growth and benzene degradation and used to propose and check a new overall kinetic model for cell growth simultaneously accounting for both product and substrate inhibitions. The results of the present study evidenced the occurrence of a competitive-type product inhibition due to 2-hydroxymuconic semialdehyde (K(iP)' = 0.902 mg(S)/L), which was stronger than the uncompetitive-type inhibition exerted by substrate (K(iS) = 7.69 mg(S)/L).

Design Concepts for Hardened Communications Structures

DTIC Science & Technology

1990-03-01

air . Based on this background, a family of structures was designed that can protect whip and directional antennae from the blast and shock effects from...Ground Surface Air Overpressure with Range, 1-MT Weapon, HOB - 0 and 500 ft ........................................... 25 5 Positive Phase Duration...design included the crater size, the e*eca field, airblast, and ground shock for ground surface air overpressure levels ranging from :5,000 to 500 psi. As

Biotransformation of 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-Hexaazaisowurtzitane (CL-20) by Denitrifying Pseudomonas sp. Strain FA1

PubMed Central

Bhushan, Bharat; Paquet, Louise; Spain, Jim C.; Hawari, Jalal

2003-01-01

The microbial and enzymatic degradation of a new energetic compound, 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), is not well understood. Fundamental knowledge about the mechanism of microbial degradation of CL-20 is essential to allow the prediction of its fate in the environment. In the present study, a CL-20-degrading denitrifying strain capable of utilizing CL-20 as the sole nitrogen source, Pseudomonas sp. strain FA1, was isolated from a garden soil. Studies with intact cells showed that aerobic conditions were required for bacterial growth and that anaerobic conditions enhanced CL-20 biotransformation. An enzyme(s) involved in the initial biotransformation of CL-20 was shown to be membrane associated and NADH dependent, and its expression was up-regulated about 2.2-fold in CL-20-induced cells. The rates of CL-20 biotransformation by the resting cells and the membrane-enzyme preparation were 3.2 ± 0.1 nmol h−1 mg of cell biomass−1 and 11.5 ± 0.4 nmol h−1 mg of protein−1, respectively, under anaerobic conditions. In the membrane-enzyme-catalyzed reactions, 2.3 nitrite ions (NO2−), 1.5 molecules of nitrous oxide (N2O), and 1.7 molecules of formic acid (HCOOH) were produced per reacted CL-20 molecule. The membrane-enzyme preparation reduced nitrite to nitrous oxide under anaerobic conditions. A comparative study of native enzymes, deflavoenzymes, and a reconstituted enzyme(s) and their subsequent inhibition by diphenyliodonium revealed that biotransformation of CL-20 is catalyzed by a membrane-associated flavoenzyme. The latter catalyzed an oxygen-sensitive one-electron transfer reaction that caused initial N denitration of CL-20. PMID:12957905

When Genome-Based Approach Meets the “Old but Good”: Revealing Genes Involved in the Antibacterial Activity of Pseudomonas sp. P482 against Soft Rot Pathogens

PubMed Central

Krzyżanowska, Dorota M.; Ossowicki, Adam; Rajewska, Magdalena; Maciąg, Tomasz; Jabłońska, Magdalena; Obuchowski, Michał; Heeb, Stephan; Jafra, Sylwia

2016-01-01

Dickeya solani and Pectobacterium carotovorum subsp. brasiliense are recently established species of bacterial plant pathogens causing black leg and soft rot of many vegetables and ornamental plants. Pseudomonas sp. strain P482 inhibits the growth of these pathogens, a desired trait considering the limited measures to combat these diseases. In this study, we determined the genetic background of the antibacterial activity of P482, and established the phylogenetic position of this strain. Pseudomonas sp. P482 was classified as Pseudomonas donghuensis. Genome mining revealed that the P482 genome does not contain genes determining the synthesis of known antimicrobials. However, the ClusterFinder algorithm, designed to detect atypical or novel classes of secondary metabolite gene clusters, predicted 18 such clusters in the genome. Screening of a Tn5 mutant library yielded an antimicrobial negative transposon mutant. The transposon insertion was located in a gene encoding an HpcH/HpaI aldolase/citrate lyase family protein. This gene is located in a hypothetical cluster predicted by the ClusterFinder, together with the downstream homologs of four nfs genes, that confer production of a non-fluorescent siderophore by P. donghuensis HYST. Site-directed inactivation of the HpcH/HpaI aldolase gene, the adjacent short chain dehydrogenase gene, as well as a homolog of an essential nfs cluster gene, all abolished the antimicrobial activity of the P482, suggesting their involvement in a common biosynthesis pathway. However, none of the mutants showed a decreased siderophore yield, neither was the antimicrobial activity of the wild type P482 compromised by high iron bioavailability. A genomic region comprising the nfs cluster and three upstream genes is involved in the antibacterial activity of P. donghuensis P482 against D. solani and P. carotovorum subsp. brasiliense. The genes studied are unique to the two known P. donghuensis strains. This study illustrates that mining of microbial genomes is a powerful approach for predictingthe presence of novel secondary-metabolite encoding genes especially when coupled with transposon mutagenesis. PMID:27303376

Novel polymer anchored Cr(III) Schiff base complexes: Synthesis, characterization and antimicrobial properties

NASA Astrophysics Data System (ADS)

Selvi, Canan; Nartop, Dilek

2012-09-01

New polymer-bound Schiff bases and Cr(III) complexes have been synthesized by the reaction of 4-benzyloxybenzaldehyde, polymer-bound with 2-aminophenol, 2-amino-4-chlorophenol and 2-amino-4-methylphenol. The structure of polymeric-Schiff bases and their Cr(III) complexes have been characterized by elemental analyses, magnetic measurements, IR, UV-Vis, TG-DTA and 1H-NMR. All these compounds have also been investigated for antibacterial activity by the well-diffusion method against Staphylococcus aureus (RSKK-07035), Shigella dysenteria type 10 (RSKK 1036), Listeria monocytogenes 4b(ATCC 19115, Escherichia coli (ATCC 1230), Salmonella typhi H (NCTC 901.8394), Staphylococcus epidermis (ATCC 12228), Brucella abortus (RSKK-03026), Micrococcs luteus (ATCC 93419, Bacillus cereus sp., Pseudomonas putida sp. and for antifungal activity against Candida albicans (Y-1200-NIH).

Electrochemical and/or microbiological treatment of pyrolysis wastewater.

PubMed

Silva, José R O; Santos, Dara S; Santos, Ubiratan R; Eguiluz, Katlin I B; Salazar-Banda, Giancarlo R; Schneider, Jaderson K; Krause, Laiza C; López, Jorge A; Hernández-Macedo, Maria L

2017-10-01

Electrochemical oxidation may be used as treatment to decompose partially or completely organic pollutants (wastewater) from industrial processes such as pyrolysis. Pyrolysis is a thermochemical process used to obtain bio-oil from biomasses, generating a liquid waste rich in organic compounds including aldehydes and phenols, which can be submitted to biological and electrochemical treatments in order to minimize its environmental impact. Thus, electrochemical systems employing dimensionally stable anodes (DSAs) have been proposed to enable biodegradation processes in subsurface environments. In order to investigate the organic compound degradation from residual coconut pyrolysis wastewater, ternary DSAs containing ruthenium, iridium and cerium synthetized by the 'ionic liquid method' at different calcination temperatures (500, 550, 600 and 700 °C) for the pretreatment of these compounds, were developed in order to allow posterior degradation by Pseudomonas sp., Bacillus sp. or Acinetobacter sp. bacteria. The electrode synthesized applying 500 °C displayed the highest voltammetric charge and was used in the pretreatment of pyrolysis effluent prior to microbial treatment. Regarding biological treatment, the Pseudomonas sp. exhibited high furfural degradation in wastewater samples electrochemically pretreated at 2.0 V. On the other hand, the use of Acinetobacter efficiently degraded phenolic compounds such as phenol, 4-methylphenol, 2,5-methylphenol, 4-ethylphenol and 3,5-methylphenol in both wastewater samples, with and without electrochemical pretreatment. Overall, the results indicate that the combination of both processes used in this study is relevant for the treatment of pyrolysis wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modelling of teeth of a gear transmission for modern manufacturing technologies

NASA Astrophysics Data System (ADS)

Monica, Z.; Banaś, W.; Ćwikla, G.; Topolska, S.

2017-08-01

The technological process of manufacturing of gear wheels is influenced by many factors. It is designated depending on the type of material from which the gear is to be produced, its heat treatment parameters, the required accuracy, the geometrical form and the modifications of the tooth. Therefor the parameters selection process is not easy and moreover it is unambiguous. Another important stage of the technological process is the selection of appropriate tools to properly machine teeth in the operations of both roughing and finishing. In the presented work the focus is put first of all on modern production methods of gears using technologically advanced instruments in comparison with conventional tools. Conventional processing tools such as gear hobbing cutters or Fellows gear-shaper cutters are used from the beginning of the machines for the production of gear wheels. With the development of technology and the creation of CNC machines designated for machining of gears wheel it was also developed the manufacturing technology as well as the design knowledge concerning the technological tools. Leading manufacturers of cutting tools extended the range of tools designated for machining of gears on the so-called hobbing cutters with inserted cemented carbide tips. The same have be introduced to Fellows gear-shaper cutters. The results of tests show that is advantaged to use hobbing cutters with inserted cemented carbide tips for milling gear wheels with a high number of teeth, where the time gains are very high, in relation to the use of conventional milling cutters.

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

PubMed

Thiyagarajan, Santhananmari; Bavya, Manoharan; Jamal, Alruwaili

2016-09-01

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

Microbial Degradation of Isopropyl-N-3-Chlorophenylcarbamate and 2-Chloroethyl-N-3-Chlorophenylcarbamate

PubMed Central

Kaufman, D. D.; Kearney, P. C.

1965-01-01

Microbial degradation of isopropyl-N-3-chlorophenylcarbamate (CIPC) and 2-chloroethyl-N-3-chlorophenylcarbamate (CEPC) was observed in a soil perfusion system. Degradation in perfused soils, and by pure cultures of effective bacterial isolates, was demonstrated by the production of 3-chloroaniline and the subsequent liberation of free chloride ion. Identified isolates effective in degrading and utilizing CIPC as a sole source of carbon included Pseudomonas striata Chester, a Flavobacterium sp., an Agrobacterium sp., and an Achromobacter sp. Identified isolates, effective in degrading and utilizing CEPC as a sole source of carbon, included an Achromobacter sp. and an Arthrobacter sp. CIPC-effective isolates degraded CEPC more slowly than CIPC, whereas CEPC-effective isolates degraded CIPC more rapidly than CEPC. Both CIPC- and CEPC-effective isolates degraded isopropyl N-phenylcarbamate (IPC) more rapidly than either CIPC or CEPC. Images Fig. 3 PMID:14325285

Denitrifying sulfide removal process on high-tetracycline wastewater.

PubMed

Liu, Chunshuang; Xu, Jian; Lee, Duu-Jong; Yu, Daoyong; Liu, Lihong

2016-04-01

Antibiotics wastewater from tetracycline (TC) production unit can have high levels of chemical oxygen demand, ammonium and sulfate and up to a few hundreds of milligrams per liter of TC. Denitrifying sulfide removal (DSR) process is set up for simultaneously removal of sulfur, carbon and nitrogen from waters. The DSR process was for the first time studied for treating TC wastewaters. The TC stress has no adverse effects on removal rates of nitrate and acetate; however, it moderately deteriorated sulfide removal rates and S(0) accumulation rates when the concentration is higher than 100mgL(-1) TC. The Thauera sp., and Pseudomonas sp. present the heterotrophs and Sulfurovum sp. presented the autotroph for the present DSR reactions. The high tolerance of TC stress by the tested consortium was explained by the excess production of extracellular polymeric substances at high TC concentration, which can bind with TC for minimizing its inhibition effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improvement the Yoghurt Nutritional Value, Organoleptic Properties and Preferences by Spirulina (Spirulina platensis) Supplementation

NASA Astrophysics Data System (ADS)

Suzery, M.; Hadiyanto; Sutanto, H.; Widiastuti, Y.; Judiono

2018-04-01

Spirulina sp has been identified as potential source food functional such as protein, amino acids and other high added value compounds from microalgae. One of the compounds is phycocyanin as also known for antioxidant use. This research was aimed to increase the nutritional value and organoleptic properties and preferences yoghurt by Spirulina platensis supplementation. Completely randomized controlled group design conducted by 31 respondents. Spirulina Research accomplished in Food Technology, Microbiology and Chemistry Laboratory at Bandung Health Polytechnic in Bandung. Samples divided randomly into three groups: (1) yoghurt standard supplemented 50 ml, (2) yoghurt and spirulina 1% supplemented 50 ml, (3) yoghurt and spirulina 1,2% supplemented 50 ml. Spirulina was added concentration by 0, 1, 1,2 % calculated by dx trial. Proximate analysis revealed the highest protein in enriched by spirulina 1%. However fat was lower 3.48 – 3.56 compare to control. All products found growing Lactobacillus acidophilus with a pH of 4.0 range. There was no microbial contamination such as E coli, Salmonella sp, Pseudomonas sp. Supplementation of spirulina to yoghurt products can be accepted by organoleptic, chemical and microbiological tests of concentrations of 1 and 1.2%. The material makes the blue colours more attractive and can be accepted by the expert panellist.

Application of Glomus sp. and Pseudomonas diminuta Reduce the Use of Chemical Fertilizers in Production of Potato Grown on Different Soil Types

NASA Astrophysics Data System (ADS)

Nurbaity, A.; Sofyan, E. T.; Hamdani, J. S.

2016-08-01

The use of high chemical fertilizer rates in potato production has been applied on the farm in Indonesia. Application of biofertilizer consists of arbuscular mycorrhizal fungi has been tested to reduce the use of NPK rates in production of potato and to determine whether different soil types will have different response to this biofertilizer. A greenhouse experiment was conducted using mixtures of spores of Glomus sp. and inoculant of mycorrhizal helper bacteria Pseudomonas diminuta, applied at different rates of NPK fertilizer (0, 25, 50, 75 and 100% of recommended rates) and different soil types (Andisols and Inceptisols). Results of experiment showed that application of Glomus sp. and P. diminuta reduced the use of NPK up to 50%, where the growth (plant height and tuber number), N,P,K uptake and tuber yields of potato had similar effect to the highest recommendation rate of NPK fertilizer. Inceptisols in general had better response to the biofertiliser compared to Andisols. Findings from this experiment confirmed the evidences that biofertilizer could reduce the use of chemical fertilizer, and the widely distributed soil in Indonesia such as Inceptisols, is potential to be used as a medium for potato production.

No Apparent Costs for Facultative Antibiotic Production by the Soil Bacterium Pseudomonas fluorescens Pf0-1

PubMed Central

Garbeva, Paolina; Tyc, Olaf; Remus-Emsermann, Mitja N. P.; van der Wal, Annemieke; Vos, Michiel; Silby, Mark; de Boer, Wietse

2011-01-01

Background Many soil-inhabiting bacteria are known to produce secondary metabolites that can suppress microorganisms competing for the same resources. The production of antimicrobial compounds is expected to incur fitness costs for the producing bacteria. Such costs form the basis for models on the co-existence of antibiotic-producing and non-antibiotic producing strains. However, so far studies quantifying the costs of antibiotic production by bacteria are scarce. The current study reports on possible costs, for antibiotic production by Pseudomonas fluorescens Pf0-1, a soil bacterium that is induced to produce a broad-spectrum antibiotic when it is confronted with non-related bacterial competitors or supernatants of their cultures. Methodology and Principal Findings We measured the possible cost of antibiotic production for Pseudomonas fluorescens Pf0-1 by monitoring changes in growth rate with and without induction of antibiotic production by supernatant of a bacterial competitor, namely Pedobacter sp.. Experiments were performed in liquid as well as on semi-solid media under nutrient-limited conditions that are expected to most clearly reveal fitness costs. Our results did not reveal any significant costs for production of antibiotics by Pseudomonas fluorescens Pf0-1. Comparison of growth rates of the antibiotic-producing wild-type cells with those of non-antibiotic producing mutants did not reveal costs of antibiotic production either. Significance Based on our findings we propose that the facultative production of antibiotics might not be selected to mitigate metabolic costs, but instead might be advantageous because it limits the risk of competitors evolving resistance, or even the risk of competitors feeding on the compounds produced. PMID:22110622

Prevalence of bacteria resistant to antibiotics and/or biocides on meat processing plant surfaces throughout meat chain production.

PubMed

Lavilla Lerma, Leyre; Benomar, Nabil; Gálvez, Antonio; Abriouel, Hikmate

2013-02-01

In order to investigate the prevalence of resistant bacteria to biocides and/or antibiotics throughout meat chain production from sacrifice till end of production line, samples from various surfaces of a goat and lamb slaughterhouse representative of the region were analyzed by the culture dependent approach. Resistant Psychrotrophs (n=255 strains), Pseudomonas sp. (n=166 strains), E. coli (n=23 strains), Staphylococcus sp. (n=17 strains) and LAB (n=82 represented mainly by Lactobacillus sp.) were isolated. Resistant psychrotrophs and pseudomonads (47 and 29%, respectively) to different antimicrobials were frequently detected in almost all areas of meat processing plant regardless the antimicrobial used, although there was a clear shift in the spectrum of other bacterial groups and for this aim such resistance was determined according to several parameters: antimicrobial tested, sampling zone and the bacterial group. Correlation of different parameters was done using a statistical tool "Principal component analysis" (PCA) which determined that quaternary ammonium compounds and hexadecylpyridinium were the most relevant biocides for resistance in Pseudomonas sp., while ciprofloxacin and hexachlorophene were more relevant for psychrotrophs, LAB, and in lesser extent Staphylococcus sp. and Escherichia coli. On the other hand, PCA of sampling zones determined that sacrifice room (SR) and cutting room (CR) considered as main source of antibiotic and/or biocide resistant bacteria showed an opposite behaviour concerning relevance of antimicrobials to determine resistance being hexadecylpyridinium, cetrimide and chlorhexidine the most relevant in CR, while hexachlorophene, oxonia 6P and PHMG the most relevant in SR. In conclusion, rotational use of the relevant biocides as disinfectants in CR and SR is recommended in an environment which is frequently disinfected. Copyright © 2012 Elsevier B.V. All rights reserved.

Structural Basis for Recognition of L-lysine, L-ornithine, and L-2,4-diamino Butyric Acid by Lysine Cyclodeaminase.

PubMed

Min, Kyungjin; Yoon, Hye-Jin; Matsuura, Atsushi; Kim, Yong Hwan; Lee, Hyung Ho

2018-04-30

L-pipecolic acid is a non-protein amino acid commonly found in plants, animals, and microorganisms. It is a well-known precursor to numerous microbial secondary metabolites and pharmaceuticals, including anticancer agents, immunosuppressants, and several antibiotics. Lysine cyclodeaminase (LCD) catalyzes β-deamination of L-lysine into L-pipecolic acid using β-nicotinamide adenine dinucleotide as a cofactor. Expression of a human homolog of LCD, μ-crystallin, is elevated in prostate cancer patients. To understand the structural features and catalytic mechanisms of LCD, we determined the crystal structures of Streptomyces pristinaespiralis LCD (SpLCD) in (i) a binary complex with NAD + , (ii) a ternary complex with NAD + and L-pipecolic acid, (iii) a ternary complex with NAD + and L-proline, and (iv) a ternary complex with NAD + and L-2,4-diamino butyric acid. The overall structure of SpLCD was similar to that of ornithine cyclodeaminase from Pseudomonas putida . In addition, SpLCD recognized L-lysine, L-ornithine, and L-2,4-diamino butyric acid despite differences in the active site, including differences in hydrogen bonding by Asp236, which corresponds with Asp228 from Pseudomonas putida ornithine cyclodeaminase. The substrate binding pocket of SpLCD allowed substrates smaller than lysine to bind, thus enabling binding to ornithine and L-2,4-diamino butyric acid. Our structural and biochemical data facilitate a detailed understanding of substrate and product recognition, thus providing evidence for a reaction mechanism for SpLCD. The proposed mechanism is unusual in that NAD + is initially converted into NADH and then reverted back into NAD + at a late stage of the reaction.

Identifying and Controlling Contamination of Date Palm Tissue Cultures.

PubMed

Abdel-Karim, Abeer H I

2017-01-01

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

Thermodynamics and folding pathway of tetraloop receptor-mediated RNA helical packing

PubMed Central

Vander Meulen, Kirk A.; Davis, Jared H.; Foster, Trenton R.; Record, M. Thomas; Butcher, Samuel E.

2008-01-01

Summary Little is known about the thermodynamic forces that drive the folding pathways of higher order RNA structure. In this study, we employ calorimetric (ITC and DSC) and spectroscopic (NMR and UV) methods to characterize the thermodynamics of the GAAA tetraloop – receptor interaction, utilizing a previously described bivalent construct. ITC studies indicate that the bivalent interaction is enthalpy-driven and highly stable, with a binding constant (Kobs) of 5.5 × 106 M−1 and enthalpy (ΔHobs°) of −33.8 kcal/mol at 45°C in 20 mM KCl and 2 mM MgCl2. Thus we derive the ΔHobs° for a single tetraloop-receptor interaction to be −16.9 kcal/mol at these conditions. UV absorbance data indicate that an increase in base stacking quality contributes to the enthalpy of complex formation. These highly favorable thermodynamics are consistent with the known critical role for the tetraloop-receptor motif in the folding of large RNAs. Additionally, a significant heat capacity change (ΔCp,obs°) of −0.24 kcal·mol−1·K−1 was determined by ITC. DSC and UV monitored thermal denaturation experiments indicate that the bivalent tetraloop-receptor construct follows a minimally 5–state unfolding pathway, and suggest the observed ΔCp,obs° for the interaction results from a temperature-dependent unbound receptor RNA structure. PMID:18845162

Bacteria Present in Comadia redtenbacheri Larvae (Lepidoptera: Cossidae).

PubMed

Hernández-Flores, L; Llanderal-Cázares, C; Guzmán-Franco, A W; Aranda-Ocampo, S

2015-09-01

The external and internal culturable bacterial community present in the larvae of Comadia redtenbacheri Hammerschmidt, an edible insect, was studied. Characterization of the isolates determined the existence of 18 morphotypes and phylogenetic analysis of the 16S rRNA gene revealed the existence of Paenibacillus sp., Bacillus safensis, Pseudomonas sp., Bacillus pseudomycoides, Corynebacterium variabile, Enterococcus sp., Gordonia sp., Acinetobacter calcoaceticus, Arthrobacter sp., Micrococcus sp., and Bacillus cereus. Greater diversity of bacteria was found in those larvae obtained from vendors than in those directly taken from Agave plants in nature. Many of the larvae obtained from vendors presented signs of potential disease, and after the analysis, results showed a greater bacterial community compared with the larvae with a healthy appearance. This indicates that bacterial flora can vary in accordance with how the larvae are handled during extraction, collection, and transport. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of the soil microbial community on mobile proportions and speciation of mercury (Hg) in contaminated soil.

PubMed

Száková, Jiřina; Havlíčková, Jitka; Šípková, Adéla; Gabriel, Jiří; Švec, Karel; Baldrian, Petr; Sysalová, Jiřina; Coufalík, Pavel; Červenka, Rostislav; Zvěřina, Ondřej; Komárek, Josef; Tlustoš, Pavel

2016-01-01

The precise characterization of the behavior of individual microorganisms in the presence of increased mercury contents in soil is necessary for better elucidation of the fate of mercury in the soil environment. In our investigation, resistant bacterial strains isolated from two mercury contaminated soils, represented by Paenibacillus alginolyticus, Burkholderia glathei, Burkholderia sp., and Pseudomonas sp., were used. Two differently contaminated soils (0.5 and 7 mg kg(-1) total mercury) were chosen. Preliminary soil analysis showed the presence of methylmercury and phenylmercury with the higher soil mercury level. Modified rhizobox experiments were performed to assess the ability of mercury accumulating strains to deplete the mobile and mobilizable mercury portions in the soil by modification; microbial agar cultures were used rather than the plant root zone. A sequential extraction procedure was performed to release the following mercury fractions: water soluble, extracted in acidic conditions, bound to humic substances, elemental, and bound to complexes, HgS and residual. Inductively coupled plasma mass spectrometry (ICP-MS) and a single-purpose atomic absorption spectrometer (AMA-254) were applied for mercury determination in the samples and extracts. Gas chromatography coupled to atomic fluorescence spectrometry (GC-AFS) was used for the determination of organomercury compounds. The analysis of the microbial community at the end of the experiment showed a 42% abundance of Paenibacillus sp. followed by Acetivibrio sp., Brevibacillus sp., Cohnella sp., Lysinibacillus sp., and Clostridium sp. not exceeding 2% abundance. The results suggest importance of Paenibacillus sp. in Hg transformation processes. This genus should be tested for potential bioremediation use in further research.

Purification and molecular and biological characterisation of the 1-hydroxyphenazine, produced by an environmental strain of Pseudomonas aeruginosa.

PubMed

Prabhu, Meghanath S; Walawalkar, Yogesh D; Furtado, Irene

2014-12-01

Pseudomonas aeruginosa--an opportunistic pathogen, perhaps best known for chronic lung infections, produces wide range of pigments that possess specific activities which either assist the organism's survival or bring about changes within host. A similar blue-green diffusible pigment producing P. aeruginosa was isolated from dug-well water, so as to extract 1-hydroxyphenazine from its crude pigment. The compound was purified from the crude pigment using column chromatography followed by a preparative thin layer chromatography that showed a single yellow spot. Further molecular characterisation of the purified component was carried out using UV-Vis spectrophotometer, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and mass spectroscopy which showed respective peaks corresponding to 1-hydroxyphenazine. Biological characterisation using in vitro assays revealed that 1-hydroxyphenazine showed anti-bacterial activity only against Bacillus sp. and a concentration of 30 µg/ml induced noticeable morphological alteration in A549 human lung adenocarcinoma cells followed by cell death after 48 h. Thus, such active components within bacterial pigments can be characterized and used as possible anti-bacterial or anti-cancer agents.

Characteristics of leachate in Foot and Mouth Disease Carcass Disposal using Molecular Biology Method

NASA Astrophysics Data System (ADS)

Choi, E. J.; Kim, B. J.; Wi, D. W.; Choi, N. C.; Lee, S. J.; Min, J. E.; Park, C. Y.

2012-04-01

The Leachate from Foot and Mouth Disease(FMD) carcass disposal by is one of the types of high-concentration contaminated wastewater with the greatest environmental impact. This is due to its pollutants: nitrate nitrogen (NO3--N) and pathogenic microorganisms. Satisfactory treatment of leachate is not an easy task for its high concentrations of nitrate nitrogen and pathogenic microorganisms. Therefore suitable FMD leachate treatment processes should be adopted to improve treatment performance and to reduce overall running costs. The objective of this study was to determine the leachate characteristics through environmental analysis and molecular biology method (bacteria identification and Polymerase Chain Reaction) using FMD leachate samples for optimal FMD leachate treatment processes. The Sixteen FMD leachate samples was obtained from carcass disposal regions in Korea. Results of environmental analysis showed that pH and Eh was observed from 5.57 to 7.40, -134~358mV. This data was exhibited typical early carcass disposal (Neutral pH and Reducing Environment by abundant organic matter). TOC and nitrate nitrogen high concentrations in FMD leachate showed a large variability from 2.3 to 38,730 mg/L(mean - 6,821.93mg/L) and 0.335 ~231.998mg/L(mean - 37.46mg/L), respectively. The result of bacteria identification was observed Bacillus cereus, Pseudomonas putida, Acinetobacter ursingii, Aeromonas hydrophila, Serratia liquefaciens, Brevundimonas naejangsanensis, Serratia liquefaciens, Pseudomonas fluorescens, Pseudomonas aeruginosa, Acinetobacter ursingii. The results of Polymerase Chain Reaction(PCR) using EzTaxon server data revealed Pseudoclavibacter helvolus, Pseudochrobactrum saccharolyticum, Corynebacterium callunae, Paenibacillus lautus, Paenibacillus sp., Bacillus arvi, Brevundimonas bullata, Acinetobacter ursingii, Lysinibacillus sphaericus, Bacillus pumilus, Bacillus sphaericus, Bacillus psychrodurans, Pseudomonas sp.

Tolerance of anaerobic bacteria to chlorinated solvents.

PubMed

Koenig, Joanna C; Groissmeier, Kathrin D; Manefield, Mike J

2014-01-01

The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation.

Tolerance of Anaerobic Bacteria to Chlorinated Solvents

PubMed Central

Koenig, Joanna C.; Groissmeier, Kathrin D.; Manefield, Mike J.

2014-01-01

The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation. PMID:24441515

Biocatalytic Desulfurization Capabilities of a Mixed Culture during Non-Destructive Utilization of Recalcitrant Organosulfur Compounds

PubMed Central

Ismail, Wael; El-Sayed, Wael S.; Abdul Raheem, Abdul Salam; Mohamed, Magdy E.; El Nayal, Ashraf M.

2016-01-01

We investigated the biodesulfurization potential of a mixed culture AK6 enriched from petroleum hydrocarbons-polluted soil with dibenzothiophene (DBT) as a sulfur source. In addition to DBT, AK6 utilized the following compounds as sulfur sources: 4-methyldibenzothiophene (4-MDBT), benzothiophene (BT), and 4,6- dimethyldibenzothiophene (4,6-DM-DBT). None of these compounds supported the growth of AK6 as the sole carbon and sulfur source. AK6 could not grow on dibenzylsulfide (DBS) as a sulfur source. The AK6 community structure changed according to the provided sulfur source. The major DGGE bands represented members of the genera Sphingobacterium, Klebsiella, Pseudomonas, Stenotrophomonas, Arthrobacter, Mycobacterium, and Rhodococcus. Sphingobacterium sp. and Pseudomonas sp. were abundant across all cultures utilizing any of the tested thiophenic S-compounds. Mycobacterium/Rhodococcus spp. were restricted to the 4-MDBT culture. The 4-MDBT culture had the highest species richness and diversity. Biodesulfurization of DBT by resting cells of AK6 produced 2-hydroxybiphenyl (2-HBP) in addition to trace amounts of phenylacetate. AK6 transformed DBT to 2-hydroxybiphenyl with a specific activity of 9 ± 0.6 μM 2-HBP g dry cell weight−1 h−1. PCR confirmed the presence in the AK6 community of the sulfur-specific (4S) pathway genes dszB and dszC. Mixed cultures hold a better potential than axenic ones for the development of a biodesulfurization technology. PMID:26973637

Endophytic Diaporthe sp. LG23 Produces a Potent Antibacterial Tetracyclic Triterpenoid.

PubMed

Li, Gang; Kusari, Souvik; Kusari, Parijat; Kayser, Oliver; Spiteller, Michael

2015-08-28

A new lanostanoid, 19-nor-lanosta-5(10),6,8,24-tetraene-1α,3β,12β,22S-tetraol (1), characterized by the presence of an aromatic B ring and hydroxylated at C-1, C-3, C-12, and C-22, was isolated from an endophytic fungus, Diaporthe sp. LG23, inhabiting leaves of the Chinese medicinal plant Mahonia fortunei. Six biosynthetically related known steroids were also isolated in parallel. Their structures were confirmed on the basis of detailed spectroscopic analysis in conjunction with the published data. Compound 1, an unusual fungus-derived 19-nor-lanostane tetracyclic triterpenoid with an aromatic B-ring system, exhibited pronounced antibacterial efficacy against both Gram-positive and -negative bacteria, especially the clinical isolates of Streptococcus pyogenes and Pseudomonas aeruginosa as well as a human pathogenic strain of Staphylococcus aureus. Our results reveal the potential of endophytes not only in conferring host fitness but also in contributing toward traditional host plant medicines.

Efflux pump-deficient mutants as a platform to search for microbes that produce antibiotics

PubMed Central

Molina-Santiago, Carlos; Udaondo, Zulema; Daddaoua, Abdelali; Roca, Amalia; Martín, Jesús; Pérez-Victoria, Ignacio; Reyes, Fernando; Ramos, Juan-Luis

2015-01-01

Pseudomonas putida DOT-T1E-18 is a strain deficient in the major antibiotic efflux pump (TtgABC) that exhibits an overall increased susceptibility to a wide range of drugs when compared with the wild-type strain. We used this strain as a platform to search for microbes able to produce antibiotics that inhibit growth. A collection of 2400 isolates from soil, sediments and water was generated and a drop assay developed to identify, via growth inhibition halos, strains that prevent the growth of DOT-T1E-18 on solid Luria–Bertani plates. In this study, 35 different isolates that produced known and unknown antibiotics were identified. The most potent inhibitor of DOT-T1E-18 growth was an isolate named 250J that, through multi-locus sequence analysis, was identified as a Pseudomonas sp. strain. Culture supernatants of 250J contain four different xantholysins that prevent growth of Gram-positive bacteria, Gram-negative and fungi. Two of the xantholysins were produced in higher concentrations and purified. Xantholysin A was effective against Bacillus, Lysinibacillus and Rhodococcus strains, and the effect against these microbes was enhanced when used in combination with other antibiotics such as ampicillin, gentamicin and kanamycin. Xantholysin C was also efficient against Gram-positive bacteria and showed an interesting antimicrobial effect against Pseudomonas strains, and a synergistic inhibitory effect with ampicillin, chloramphenicol and gentamicin. PMID:26059350

[Pharmaceutical use and antibiotic therapy in intensive care units].

PubMed

Gauzit, R

2000-05-01

The present study has involved a sample of 750 medical or medical/surgical intensive care units. The aim was to identify the variations of antibiotic (AB) use, measured in monetary terms, and to sort out explicative variables accounting for the corresponding expense. Activity and expense data have been recorded for 1997. "Second intention" antibiotics have been defined as follows: imipenem, ceftazidime, cefpirome, cefepime, piperacillin/tazobactam, amikacin, isepamicin, vancomycin and teicoplanin. Only 60 evaluable sheets have been sent back. They include data about 28,000 admissions and 183,960 hospital days. The results are presented as means +/- standard deviation (SD) and the variability has been considered to be important if the ratio SD/mean was > 1. Nosocomial infections (NI) surveillance, antibiotic advisory board and restriction of use for some molecules were present in 95%, 67% and 78% of units, respectively. The units usually had 10 beds (range: 6-24) and the mean activity was 468 +/- 184 admissions/year and 3,066 +/- 1,454 hospital days/year. Mean duration of hospitalisation (MDH) was 6.9 +/- 2.7 days and mean omega score 114 +/- 61. Mean age of patients was 56.5 years, IGS II score 35.7 +/- 7; 29 +/- 16% of patients were mechanically ventilated for more than 48 hours and mortality rate was 17 +/- 7%. The mean number of bacterial isolates per unit was 369 +/- 323: Staphylococcus sp. 30% [including 25% of meticillin-resistant Staphylococcus aureus (MRSA)]; enterobacteria 30% (including 14% of cefotaxime-resistant isolates); Pseudomonas sp. 14% (including 40% of ticarcillin R isolates); other 26%. Pharmaceutical expense was 834 +/- 364 FF per day of hospitalisation, including 536 +/- 273 FF for drugs. Antibiotics accounted for 32% of the expense and second intention molecules for nearly 50% of antibiotic expense. More than 80% of antibiotic expense was accounted for by only 10 molecules. The mean cost/hospital day for the most expensive antibiotic, whatever the molecule ranking first, was 27 FF, for the second and third ones 18 and 14 FF. The expense for the tenth molecule was only 3 FF. There was a correlation between antibiotic expense and number of beds, number of hospital days, MDH, omega score, number of patients mechanically ventilated for more than 48 hours, mortality, number of bacterial isolates and incidence of NI. Molecules thought to be active against MRSA and ticarcillin-resistant Pseudomonas sp. accounted for 7 and 20% of total antibiotic expense, as compared to 7.5 and 4.6%, respectively, of bacterial isolates. As a conclusion, in this sample of 60 intensive care units, differences were shown for the cost of antibiotics, but the variability was low, without major discrepancies. Ten molecules accounted for 83% of total antibiotic expense. The financial impact of molecules against ticarcillin-resistant Pseudomonas sp is high.

Promotion of arsenic phytoextraction efficiency in the fern Pteris vittata by the inoculation of As-resistant bacteria: a soil bioremediation perspective.

PubMed

Lampis, Silvia; Santi, Chiara; Ciurli, Adriana; Andreolli, Marco; Vallini, Giovanni

2015-01-01

A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: (i) non-inoculated plants; (ii) plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A); (iii) plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4, and Pseudoxanthomonas sp. P4V6 (B), and (iv) plants inoculated with all five bacterial strains (AB). The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community.

Isolation and characterization of a novel, T7-like phage against Aeromonas veronii.

PubMed

Anand, Taruna; Bera, Bidhan Ch; Virmani, Nitin; Vaid, Rajesh Kumar; Vashisth, Medhavi; Tripathi, Bhupendra Nath

2018-02-01

A virulent Aeromonas veronii biovar sobria and the corresponding novel, lytic bacteriophage (VTCCBPA5) were isolated from village pond water. The phage was found to belong to family Podoviridae. PCR analysis of major capsid protein gene confirmed its classification to T7-like genus. The protein profiling by SDS-PAGE indicated the major structural protein to be ~ 45 kDa. The phage (VTCCBPA5) is host specific and is stable over a range of pH (6-10) and temperatures (4-45 °C). On the basis of restriction endonuclease analysis combined with prediction mapping, it was observed to vary significantly from previously reported podophages of Aeromonas sp., viz. phiAS7 and Ahp1. The phylogenetic analysis on the basis of PCR-amplified segment of DNA polymerase gene of phage revealed it being an outgroup from podophages of Klebsiella sp. and Pseudomonas sp. though a small internal fragment (359 bp) showed the highest identity (77%) with Vibrio sp. phages. Thus, this is the first report of a novel Podoviridae phage against A. veronii. It expands the assemblage of podophages against Aeromonas sp. and BPA5 could be potentially useful in biocontrol of environmentally acquired Aeromonas veronii infections.

Explosive Infrasonic Events: Sensor Comparison Experiment (SCE)

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

Schnurr, J. M.; Garces, M.; Rodgers, A. J.

SCE (sensor comparison experiment) 1 through 4 consists of a series of four controlled above-ground explosions designed to provide new data for overpressure propagation. Infrasound data were collected by LLNL iPhones and other sensors. Origin times, locations HOB, and yields are not being released at this time and are therefore not included in this report. This preliminary report will be updated as access to additional data changes, or instrument responses are determined.

Introduction of Atrazine-Degrading Pseudomonas SP. Strain ADP to Enhance Phytoremediation of Atrazine

USDA-ARS?s Scientific Manuscript database

Atrazine (ATR) has been widely applied in the US Midwestern states. Public health and ecological concerns have been raised about contamination of surface and ground water by ATR and its chlorinated metabolites, due to their toxicity and potential carcinogenic or endocrinology effects. Phytoremediati...

Simulation Study of Near-Surface Coupling of Nuclear Devices vs. Equivalent High-Explosive Charges

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

Fournier, Kevin B; Walton, Otis R; Benjamin, Russ

2014-09-29

A computational study was performed to examine the differences in near-surface ground-waves and air-blast waves generated by high-explosive energy sources and those generated by much higher energy - density low - yield nuclear sources. The study examined the effect of explosive-source emplacement (i.e., height-of-burst, HOB, or depth-of-burial, DOB) over a range from depths of -35m to heights of 20m, for explosions with an explosive yield of 1-kt . The chemical explosive was modeled by a JWL equation-of-state model for a ~14m diameter sphere of ANFO (~1,200,000kg – 1 k t equivalent yield ), and the high-energy-density source was modeled asmore » a one tonne (1000 kg) plasma of ‘Iron-gas’ (utilizing LLNL’s tabular equation-of-state database, LEOS) in a 2m diameter sphere, with a total internal-energy content equivalent to 1 k t . A consistent equivalent-yield coupling-factor approach was developed to compare the behavior of the two sources. The results indicate that the equivalent-yield coupling-factor for air-blasts from 1 k t ANFO explosions varies monotonically and continuously from a nearly perfec t reflected wave off of the ground surface for a HOB ≈ 20m, to a coupling factor of nearly zero at DOB ≈ -25m. The nuclear air - blast coupling curve, on the other hand, remained nearly equal to a perfectly reflected wave all the way down to HOB’s very near zero, and then quickly dropped to a value near zero for explosions with a DOB ≈ -10m. The near - surface ground - wave traveling horizontally out from the explosive source region to distances of 100’s of meters exhibited equivalent - yield coupling - factors t hat varied nearly linearly with HOB/DOB for the simulated ANFO explosive source, going from a value near zero at HOB ≈ 5m to nearly one at DOB ≈ -25m. The nuclear-source generated near-surface ground wave coupling-factor remained near zero for almost all HOB’s greater than zero, and then appeared to vary nearly - linearly with depth-of-burial until it reached a value of one at a DOB between 15m and 20m. These simulations confirm the expected result that the variation of coupling to the ground, or the air, change s much more rapidly with emplacement location for a high-energy-density (i.e., nuclear-like) explosive source than it does for relatively low - energy - density chemical explosive sources. The Energy Partitioning, Energy Coupling (EPEC) platform at LLNL utilizes laser energy from one quad (i.e. 4-laser beams) of the 192 - beam NIF Laser bank to deliver ~10kJ of energy to 1mg of silver in a hohlraum creating an effective small-explosive ‘source’ with an energy density comparable to those in low-yield nuclear devices. Such experiments have the potential to provide direct experimental confirmation of the simulation results obtained in this study, at a physical scale (and time-scale) which is a factor of 1000 smaller than the spatial- or temporal-scales typically encountered when dealing with nuclear explosions.« less

Diversity of bacteria producing pigmented colonies in aerosol, snow and soil samples from remote glacial areas (Antarctica, Alps and Andes)

NASA Astrophysics Data System (ADS)

González-Toril, E.; Amils, R.; Delmas, R. J.; Petit, J.-R.; Komárek, J.; Elster, J.

2008-04-01

Four different communities and one culture of pigmented microbial assemblages were obtained by incubation in mineral medium of samples collected from high elevation snow in the Alps (Mt. Blanc area) and the Andes (Nevado Illimani summit, Bolivia), from Antarctic aerosol (French station Dumont d'Urville) and a maritime Antarctic soil (King George Island, South Shetlands, Uruguay Station Artigas). Molecular analysis of more than 200 16S rRNA gene sequences showed that all cultured cells belong to the Bacteria domain. The phylogenetic comparison with the currently available rDNA database allowed the identification of sequences belonging to Proteobacteria (Alpha-, Beta- and Gamma-proteobacteria), Actinobacteria and Bacteroidetes phyla. The Andes snow culture was the richest in bacterial diversity (eight microorganisms identified) and the maritime Antarctic soil the poorest (only one). Snow samples from Col du midi (Alps) and the Andes shared the highest number of identified microorganisms (Agrobacterium, Limnobacter, Aquiflexus and two uncultured Alphaproteobacteria clones). These two sampling sites also shared four sequences with the Antarctic aerosol sample (Limnobacter, Pseudonocardia and an uncultured Alphaproteobacteria clone). The only microorganism identified in the maritime Antarctica soil (Brevundimonas sp.) was also detected in the Antarctic aerosol. The two snow samples from the Alps only shared one common microorganism. Most of the identified microorganisms have been detected previously in cold environments (Dietzia kujamenisi, Pseudonocardia Antarctica, Hydrogenophaga palleronii and Brebundimonas sp.), marine sediments (Aquiflexus balticus, Pseudomonas pseudoalkaligenes, Pseudomonas sp. and one uncultured Alphaproteobacteria), and soils and rocks (Pseudonocardia sp., Agrobactrium sp., Limnobacter sp. and two uncultured Alphaproteobacetria clones). Air current dispersal is the best model to explain the presence of very specific microorganisms, like those used in this work, in very distant environments. In addition these microorganisms have to be resistant to extreme conditions and able to grow in oligotrophic environments. Considering the habitats in which they have been identified, the presence of pigments must be related with their ability to resist high doses of radiation.

Regulation of Soluble Phosphate on the Ability of Phytate Mineralization and β-Propeller Phytase Gene Expression of Pseudomonas fluorescens JZ-DZ1, a Phytate-Mineralizing Rhizobacterium.

PubMed

Shen, Lan; Wu, Xiao-Qin; Zeng, Qing-Wei; Liu, Hong-Bin

2016-12-01

Phytate-mineralizing rhizobacteria (PMR) play an important role in providing phosphorus for the sustainable plant growth. It is important to investigate the ability of PMR to produce phytase under different phosphate levels for its application. The effects of different concentrations of soluble phosphate on the ability of phytate mineralization of Pseudomonas fluorescens JZ-DZ1, a phytate-mineralizing rhizobacterium, were investigated in both solid and liquid media. The results on solid media showed that halo zone width gradually reduced with concentrations of soluble phosphate increasing from 0.05 to 20 mM, indicating the reduction of the ability of phytate mineralization. The results were consistent with the quantitative detection of phytase activity from the overall trend. An 1866-bp β-propeller phytase (BPP) gene (phyPf) was cloned from the strain, and the deduced amino acid sequence of phyPf shared 98 % of identity with a known BPP from Pseudomonas sp. BS10-3 (AJF36073.1). The results of relative real-time quantitative PCR assay showed that the expression of phyPf was induced by a low concentration (0.1 mM) of soluble phosphate, suggesting that BPP secretion was regulated by gene phyPf. The BPP-harboring bacterium P. fluorescens JZ-DZ1 with low phosphate-inducible ability of phytate mineralization could be potentially applied to promote phosphorus uptake for plants in the future.

Structure of the detoxification catalyst mercuric ion reductase from Bacillus sp. strain RC607

NASA Astrophysics Data System (ADS)

Schiering, N.; Kabsch, W.; Moore, M. J.; Distefano, M. D.; Walsh, C. T.; Pai, E. F.

1991-07-01

SEVERAL hundred million tons of toxic mercurials are dispersed in the biosphere1. Microbes can detoxify organo-mercurials and mercury salts through sequential action of two enzymes, organomercury lyase2 and mercuric ion reductase (MerA) 3-5. The latter, a homodimer with homology to the FAD-dependent disulphide oxidoreductases6, catalyses the reaction NADPH + Hg(II) --> NADP+ + H+Hg(0), one of the very rare enzymic reactions with metal substrates. Human glutathione reductase7,8 serves as a reference molecule for FAD-dependent disulphide reductases and between its primary structure9 and that of MerA from Tn501 (Pseudomonas), Tn21 (Shigella), pI258 (Staphylococcus) and Bacillus, 25-30% of the residues have been conserved10,11. All MerAs have a C-terminal extension about 15 residues long but have very varied N termini. Although the enzyme from Streptomyces lividans has no addition, from Pseudomonas aeruginosa Tn5Ol and Bacillus sp. strain RC607 it has one and two copies respectively of a domain of 80-85 residues, highly homologous to MerP, the periplasmic component of proteins encoded by the mer operon11. These domains can be proteolytically cleaved off without changing the catalytic efficiency3. We report here the crystal structure of MerA from the Gram-positive bacterium Bacillus sp. strain RC607. Analysis of its complexes with nicotinamide dinucleotide substrates and the inhibitor Cd(II) reveals how limited structural changes enable an enzyme to accept as substrate what used to be a dangerous inhibitor. Knowledge of the mode of mercury ligation is a prerequisite for understanding this unique detoxification mechanism.

Computer assisted screening, correction, and analysis of historical weather measurements

NASA Astrophysics Data System (ADS)

Burnette, Dorian J.; Stahle, David W.

2013-04-01

A computer program, Historical Observation Tools (HOB Tools), has been developed to facilitate many of the calculations used by historical climatologists to develop instrumental and documentary temperature and precipitation datasets and makes them readily accessible to other researchers. The primitive methodology used by the early weather observers makes the application of standard techniques difficult. HOB Tools provides a step-by-step framework to visually and statistically assess, adjust, and reconstruct historical temperature and precipitation datasets. These routines include the ability to check for undocumented discontinuities, adjust temperature data for poor thermometer exposures and diurnal averaging, and assess and adjust daily precipitation data for undercount. This paper provides an overview of the Visual Basic.NET program and a demonstration of how it can assist in the development of extended temperature and precipitation datasets using modern and early instrumental measurements from the United States.

Inoculating plants with the endophytic bacterium Pseudomonas sp. Ph6-gfp to reduce phenanthrene contamination.

PubMed

Sun, Kai; Liu, Juan; Gao, Yanzheng; Sheng, Yuehui; Kang, Fuxing; Waigi, Michael Gatheru

2015-12-01

Plant organic contamination poses a serious threat to the safety of agricultural products and human health worldwide, and the association of endophytic bacteria with host plants may decrease organic pollutants in planta. In this study, we firstly determined the growth response and biofilm formation of endophytic Pseudomonas sp. Ph6-gfp, and then systematically evaluated the performance of different plant colonization methods (seed soaking (SS), root soaking (RS), leaf painting (LP)) for circumventing the risk of plant phenanthrene (PHE) contamination. After inoculation for 48 h, strain Ph6-gfp grew efficiently with PHE, oxalic acid, or malic acid as the sole sources of carbon and energy. Moreover, strain Ph6-gfp could form robust biofilms in LB medium. In greenhouse hydroponic experiments, strain Ph6-gfp could actively colonize inoculated plants internally, and plants colonized with Ph6-gfp showed a higher capacity for PHE removal. Compared with the Ph6-gfp-free treatment, the accumulations of PHE in Ph6-gfp-colonized plants via SS, RS, and LP were 20.1, 33.1, and 7.1 %, respectively, lower. Our results indicate that inoculating plants with Ph6-gfp could lower the risk of plant PHE contamination. RS was most efficient for improving PHE removal in whole plant bodies by increasing the cell numbers of Ph6-gfp in plant roots. The findings in this study provide an optimized method to strain Ph6-gfp reduce plant PAH residues, which may be applied to agricultural production in PAH-contaminated soil.

The anti-biofouling behavior of high voltage pulse electric field (HPEF) mediated by carbon fiber composite coating in seawater.

PubMed

Feng, Tiantian; Wu, Jinyi; Chai, Ke; Yang, Pengpeng

2018-04-25

One of the most important research areas in the marine industry is to investigate new and effective anti-biofouling technologies. In this study, high voltage pulse electric field (HPEF) mediated by carbon fiber (CF) composite coating was utilized to prevent the fouling of bacteria, microalgae and barnacle larvae in seawater. The plate count, 2, 3, 5-triphenyl-tetrazolium chloride (TTC) reduction assay and neutral red (NR) staining and larval motility detection showed that the inactivation rates were at the highest levels, which reached 99.1%, 99.9%, 99.7%, 98.7% and 85% respectively for Pseudomonas sp., Vibrio sp., iron bacteria, Navicula sp. and the second stage nauplii of Balanus reticulatus, under the HPEF with 19 kV pulse amplitude, 23.15 kHz frequency and 0.5 duty cycle. The field-emission scanning electron microscopy (FE-SEM) of Navicula sp. revealed that the HPEF brought about the cell lysis and the cell organic matter release on the coating, which could be the mechanism of the inactivation by the HPEF. Additionally, the FE-SEM and Raman spectroscopy indicated that the HPEF hardly damaged the coating. Copyright © 2018 Elsevier B.V. All rights reserved.

PCE dechlorination by non-Dehalococcoides in a microbial electrochemical system.

PubMed

Yu, Jaecheul; Park, Younghyun; Nguyen, Van Khanh; Lee, Taeho

2016-08-01

The bioremediation of tetrachloroethene (perchloroethene; PCE) contaminated sites generally requires a supply of some fermentable organic substrates as an electron donor. On the other hand, organic substrates can induce the massive growth of microorganisms around the injection wells, which can foul the contaminated subsurface environment. In this study, PCE dechlorination to ethene was performed in a microbial electrochemical system (MES) using the electrode (a cathode polarized at -500 mV vs. standard hydrogen electrode) as the electron donor. Denaturing gel gradient electrophoresis and pyrosequencing revealed a variety of non-Dehalococcoides bacteria dominant in MES, such as Acinetobacter sp. (25.7 % for AS1 in suspension of M3), Rhodopseudomonas sp. (10.5 % for AE1 and 10.1 % for AE2 in anodic biofilm of M3), Pseudomonas aeruginosa (22.4 % for BS1 in suspension of M4), and Enterobacter sp. (21.7 % for BE1 in anodic biofilm of M4) which are capable of electron transfer, hydrogen production and dechlorination. The Dehalococcoides group, however, was not detected in this system. Therefore, these results suggest that a range of bacterial species outside the Dehalococcoides can play an important role in the microbial electrochemical dechlorination process, which may lead to innovative bioremediation technology.

[The effect of selected antibiotics on microorganisms contaminating boar ejaculate].

PubMed

Mazurová, J; Vinter, P

1991-04-01

The occurrence of microorganisms, including their total counts in boar native ejaculates, was investigated in two stages; the objective of this investigation also was to determine contamination after the sperms were treated with diluents containing the antibiotics ampicillin, gentamycin, apramycin, cefoxitin, or antibiotic combinations penicillin + streptomycin, ampicillin + cefoxitin, gentamycin + cefoxitin and ampicillin + gentamycin. The representation of bacterial species and total counts of microbes in 1 ml diluted sperm stored at a temperature of about 18 degrees C were determined in 24, 48 and 72 h after dilution. The microorganisms were cultivated from all native ejaculates. Proteus sp. (63.3%) and Pseudomonas aeruginosa (51.5% of the total number of examined samples) were the most frequent species. The number of contaminated diluted ejaculates ranged from 12.5 to 95.8% in 24 h after dilution, from 12.5 to 98.5% in 48 h and from 16.8 to 95.8% of the total number of examined ejaculates in 72 h. The occurrence of microorganisms correlated mostly with the efficiency spectrum of the antibiotics or their combinations. The average counts of microorganisms in 1 ml of native ejaculate made 2,363,000 in stage I and 1,472,108 in stage II. The highest average counts in 1 ml of diluted sperm were found in ejaculates containing cefoxitin and apramycin. Gentamycin was the most effective antibiotic used as a sole component (average counts of microorganisms CPM in 1 ml were 416 in 24 h, 955 in 48 h and 2260 in 72 h after dilution); ampicillin and gentamycin were the most efficient combination (14--20--21). This combination exerted very good effects also on Proteus sp. and Pseudomonas aeruginosa.

Growth Enhancement and Developmental Modifications of in Vitro Grown Potato (Solanum tuberosum spp. tuberosum) as Affected by a Nonfluorescent Pseudomonas sp. 1

PubMed Central

Frommel, Marcos I.; Nowak, Jerzy; Lazarovits, George

1991-01-01

A plant growth-promoting rhizobacterium, designated Ps JN and isolated from onion roots, was identified as a nonfluorescent Pseudomonas sp. The percentage of similarity of Ps JN to P. gladioli (NCPPB 1891), P. cichorii (NCPPB 943), and P. viridiflava (NCPPB 635), as determined from 135 biochemical and physiological tests was 77, 70, and 66%, respectively. Ps JN persisted through successive generations of in vitro cultured potato plantlets, both as endophytic and epiphytic populations. In vitro inoculated potato (Solanum tuberosum) nodal explants produced plantlets with significant increases in root number (24-196%), root dry weight (44-201%), haulm dry weight (14-151%), and stem length (26-28%) as compared with noninoculated control plants. Bacterization also enhanced leaf hair formation (55-110%), secondary root branching, and total plant lignin content (43%). Other root colonizing bacteria or heat-killed cells of Ps JN had no significant effect on plant growth. Detached leaves from in vitro grown control plants, when exposed to 19°C and 50% relative humidity, lost 55% of their moisture content in 2.5 hours. Moisture loss by leaves of in vitro grown, bacterized plants, as well as greenhouse-acclimated, bacterized plants, and control plants, was less than 20%. Changes in stomatal closure appear to account for this difference. ImagesFigure 2Figure 4 PMID:16668277

Alendronate and raloxifene affect the osteoprotegerin/RANKL system in human osteoblast primary cultures from patients with osteoporosis and osteoarthritis.

PubMed

Giner, Mercè; Rios, Ma José; Montoya, Ma José; Vázquez, Ma Angeles; Miranda, Cristina; Pérez-Cano, Ramón

2011-01-15

The osteoprotegerin/RANKL system modulates bone remodelling. Alendronate and raloxifene are anti-resorptive drugs effective in osteoporotic disease. They reduce fracture risk, the activity of bone remodelling and increase bone mineral density. It is not known if they can exert a direct effect in osteoblasts via the osteoprotegerin/RANKL system. Our objective was to assess the effects of alendronate and raloxifene among osteoprotegerin production (ELISA), as well as osteoprotegerin and RANKL expression (RT-PCR), in primary cultures of human osteoblasts (hOB). We compared 17 osteoporotic patients with 16 patients affected by osteoarthritis in basal conditions and after incubation with alendronate (10(-6) M), raloxifene (10(-7) M) or 17-β estradiol (10(-7) M) for 24 h. The statistical analysis was determined by ANOVA. Osteoprotegerin protein secretion in hOB cultures was higher in patients with osteoporosis than osteoarthritis. Osteoprotegerin secretion levels remained unchanged after each treatment. The osteoporotic group was more sensitive to treatment. Both raloxifene (34%) and estradiol (37%) increased osteoprotegerin mRNA expression, and alendronate (118%) and raloxifene (61%) increased the mRNA expression of RANKL. The RANKL/osteoprotegerin mRNA ratio was higher in osteoporotic than osteoarthritic patients. In the osteoporotic group, the RANKL/osteoprotegerin mRNA ratio was significantly increased after treatment with alendronate (112%) and after treatment with raloxifene (60%). These results indicate a direct action of alendronate and raloxifene on hOB cultures from osteoporotic patients, and the cited drugs are able to modulate the osteoprotegerin/RANKL system. Copyright © 2010 Elsevier B.V. All rights reserved.

Characterization and structure prediction of partial length protein sequences of pcoA, pcoR and chrB genes from heavy metal resistant bacteria from the Klip River, South Africa.

PubMed

Chihomvu, Patience; Stegmann, Peter; Pillay, Michael

2015-04-01

The Klip River has suffered from severe anthropogenic effects from industrial activities such as mining. Long-term exposure to heavy metal pollution has led to the development of heavy metal resistant strains of Pseudomonas sp. KR23, Lysinibacillus sp. KR25, and E. coli KR29. The objectives of this study were to characterize the genetics of copper and chromate resistance of the isolates. Copper and chromate resistance determinants were cloned and sequenced. Open reading frames (ORFs) related to the genes CopA and CopR were identified in E. coli KR29, PcoA in Lysinibacillus sp. KR25 and none related to chromate resistance were detected. The 3D-models predicted by I-TASSER disclose that the PcoA proteins consist of β-sheets, which form a part of the cupredoxin domain of the CopA copper resistance family of genes. The model for PcoR_29 revealed the presence of a helix turn helix; this forms part of a DNA binding protein, which is part of a heavy metal transcriptional regulator. The bacterial strains were cured using ethidium bromide. The genes encoding for heavy metal resistance and antibiotic resistance were found to be located on the chromosome for both Pseudomonas sp. (KR23) and E. coli (KR29). For Lysinibacillus (KR25) the heavy metal resistance determinants are suspected to be located on a mobile genetic element, which was not detected using gel electrophoresis.

Characterization and Structure Prediction of Partial Length Protein Sequences of pcoA, pcoR and chrB Genes from Heavy Metal Resistant Bacteria from the Klip River, South Africa

PubMed Central

Chihomvu, Patience; Stegmann, Peter; Pillay, Michael

2015-01-01

The Klip River has suffered from severe anthropogenic effects from industrial activities such as mining. Long-term exposure to heavy metal pollution has led to the development of heavy metal resistant strains of Pseudomonas sp. KR23, Lysinibacillus sp. KR25, and E. coli KR29. The objectives of this study were to characterize the genetics of copper and chromate resistance of the isolates. Copper and chromate resistance determinants were cloned and sequenced. Open reading frames (ORFs) related to the genes CopA and CopR were identified in E. coli KR29, PcoA in Lysinibacillus sp. KR25 and none related to chromate resistance were detected. The 3D-models predicted by I-TASSER disclose that the PcoA proteins consist of β-sheets, which form a part of the cupredoxin domain of the CopA copper resistance family of genes. The model for PcoR_29 revealed the presence of a helix turn helix; this forms part of a DNA binding protein, which is part of a heavy metal transcriptional regulator. The bacterial strains were cured using ethidium bromide. The genes encoding for heavy metal resistance and antibiotic resistance were found to be located on the chromosome for both Pseudomonas sp. (KR23) and E. coli (KR29). For Lysinibacillus (KR25) the heavy metal resistance determinants are suspected to be located on a mobile genetic element, which was not detected using gel electrophoresis. PMID:25837632

Constitutively expressed COX-2 in osteoblasts positively regulates Akt signal transduction via suppression of PTEN activity.

PubMed

Li, Ching-Ju; Chang, Je-Ken; Wang, Gwo-Jaw; Ho, Mei-Ling

2011-02-01

Cyclooxygenase-2 (COX-2) is thought to be an inducible enzyme, but increasing reports indicate that COX-2 is constitutively expressed in several organs. The status of COX-2 expression in bone and its physiological role remains undefined. Non-selective non-steroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 inhibitors, which commonly suppress COX-2 activity, were reported to suppress osteoblast proliferation via Akt/FOXO3a/p27(Kip1) signaling, suggesting that COX-2 may be the key factor of the suppressive effects of NSAIDs on proliferation. Although Akt activation correlates with PTEN deficiency and cell viability, the role of COX-2 on PTEN/Akt regulation remains unclear. In this study, we hypothesized that COX-2 may be constitutively expressed in osteoblasts and regulate PTEN/Akt-related proliferation. We examined the localization and co-expression of COX-2 and p-Akt in normal mouse femurs and in cultured mouse (mOBs) and human osteoblasts (hOBs). Our results showed that osteoblasts adjacent to the trabeculae, periosteum and endosteum in mouse femurs constitutively expressed COX-2, while COX-2 co-expressed with p-Akt in osteoblasts sitting adjacent to trabeculae in vivo, and in mOBs and hOBs in vitro. We further used COX-2 siRNA to test the role of COX-2 in Akt signaling in hOBs; COX-2 silencing significantly inhibited PTEN phosphorylation, enhanced PTEN activity, and suppressed p-Akt level and proliferation. However, replenishment of the COX-2 enzymatic product, PGE2, failed to reverse COX-2-dependent Akt phosphorylation. Furthermore, transfection with recombinant human COX-2 (rhCOX-2) significantly reversed COX-2 siRNA-suppressed PTEN phosphorylation, but this effect was reduced when the enzymatic activity of rhCOX-2 was blocked. This finding indicated that the effect of COX-2 on PTEN/Akt signaling is not related to PGE2 but still dependent on COX-2 enzymatic activity. Conversely, COX-1 silencing did not affect PTEN/Akt signaling. Our findings provide new insight into bone physiology; namely, that COX-2 is constitutively expressed in osteoblasts in the dynamic bone growth area, which facilitates osteoblast proliferation via PTEN/Akt/p27(Kip1) signaling. Copyright © 2010 Elsevier Inc. All rights reserved.

Effect of Pseudomonas sp. P7014 on the growth of edible mushroom Pleurotus eryngii in bottle culture for commercial production.

PubMed

Kim, Min Keun; Math, Renukaradhya K; Cho, Kye Man; Shin, Ki Jae; Kim, Jong Ok; Ryu, Jae San; Lee, Young Han; Yun, Han Dae

2008-05-01

Addition of bacterial culture strain P7014 and its supernatant to the mushroom growing media resulted in mushroom mycelia run faster. Mycelial growth rate of Pleurotus eryngii was increased up to 1.6 fold and primordial formation was induced one day earlier. Moreover, it was supposed that addition of bacteria had beneficial applications for commercial mushroom production, which appreciably reduced total number of days for cultivation of about 5+/-2 days compared with uninoculated, which took 55+/-2 days.

Endosteal-like extracellular matrix expression on melt electrospun written scaffolds.

PubMed

Muerza-Cascante, Maria Lourdes; Shokoohmand, Ali; Khosrotehrani, Kiarash; Haylock, David; Dalton, Paul D; Hutmacher, Dietmar W; Loessner, Daniela

2017-04-01

Tissue engineering technology platforms constitute a unique opportunity to integrate cells and extracellular matrix (ECM) proteins into scaffolds and matrices that mimic the natural microenvironment in vitro. The development of tissue-engineered 3D models that mimic the endosteal microenvironment enables researchers to discover the causes and improve treatments for blood and immune-related diseases. The aim of this study was to establish a physiologically relevant in vitro model using 3D printed scaffolds to assess the contribution of human cells to the formation of a construct that mimics human endosteum. Melt electrospun written scaffolds were used to compare the suitability of primary human osteoblasts (hOBs) and placenta-derived mesenchymal stem cells (plMSCs) in (non-)osteogenic conditions and with different surface treatments. Using osteogenic conditions, hOBs secreted a dense ECM with enhanced deposition of endosteal proteins, such as fibronectin and vitronectin, and osteogenic markers, such as osteopontin and alkaline phosphatase, compared to plMSCs. The expression patterns of these proteins were reproducibly identified in hOBs derived from three individual donors. Calcium phosphate-coated scaffolds induced the expression of osteocalcin by hOBs when maintained in osteogenic conditions. The tissue-engineered endosteal microenvironment supported the growth and migration of primary human haematopoietic stem cells (HSCs) when compared to HSCs maintained using tissue culture plastic. This 3D testing platform represents an endosteal bone-like tissue and warrants future investigation for the maintenance and expansion of human HSCs. This work is motivated by the recent interest in melt electrospinning writing, a 3D printing technique used to produce porous scaffolds for biomedical applications in regenerative medicine. Our team has been among the pioneers in building a new class of melt electrospinning devices for scaffold-based tissue engineering. These scaffolds allow structural support for various cell types to invade and deposit their own ECM, mimicking a characteristic 3D microenvironment for experimental studies. We used melt electrospun written polycaprolactone scaffolds to develop an endosteal bone-like tissue that promotes the growth of HSCs. We combine tissue engineering concepts with cell biology and stem cell research to design a physiologically relevant niche that is of prime interest to the scientific community. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa.

PubMed

Bosire, Erick M; Blank, Lars M; Rosenbaum, Miriam A

2016-08-15

Pseudomonas aeruginosa is an important, thriving member of microbial communities of microbial bioelectrochemical systems (BES) through the production of versatile phenazine redox mediators. Pure culture experiments with a model strain revealed synergistic interactions of P. aeruginosa with fermenting microorganisms whereby the synergism was mediated through the shared fermentation product 2,3-butanediol. Our work here shows that the behavior and efficiency of P. aeruginosa in mediated current production is strongly dependent on the strain of P. aeruginosa We compared levels of phenazine production by the previously investigated model strain P. aeruginosa PA14, the alternative model strain P. aeruginosa PAO1, and the BES isolate Pseudomonas sp. strain KRP1 with glucose and the fermentation products 2,3-butanediol and ethanol as carbon substrates. We found significant differences in substrate-dependent phenazine production and resulting anodic current generation for the three strains, with the BES isolate KRP1 being overall the best current producer and showing the highest electrochemical activity with glucose as a substrate (19 μA cm(-2) with ∼150 μg ml(-1) phenazine carboxylic acid as a redox mediator). Surprisingly, P. aeruginosa PAO1 showed very low phenazine production and electrochemical activity under all tested conditions. Microbial fuel cells and other microbial bioelectrochemical systems hold great promise for environmental technologies such as wastewater treatment and bioremediation. While there is much emphasis on the development of materials and devices to realize such systems, the investigation and a deeper understanding of the underlying microbiology and ecology are lagging behind. Physiological investigations focus on microorganisms exhibiting direct electron transfer in pure culture systems. Meanwhile, mediated electron transfer with natural redox compounds produced by, for example, Pseudomonas aeruginosa might enable an entire microbial community to access a solid electrode as an alternative electron acceptor. To better understand the ecological relationships between mediator producers and mediator utilizers, we here present a comparison of the phenazine-dependent electroactivities of three Pseudomonas strains. This work forms the foundation for more complex coculture investigations of mediated electron transfer in microbial fuel cells. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa

PubMed Central

Bosire, Erick M.; Blank, Lars M.

2016-01-01

ABSTRACT Pseudomonas aeruginosa is an important, thriving member of microbial communities of microbial bioelectrochemical systems (BES) through the production of versatile phenazine redox mediators. Pure culture experiments with a model strain revealed synergistic interactions of P. aeruginosa with fermenting microorganisms whereby the synergism was mediated through the shared fermentation product 2,3-butanediol. Our work here shows that the behavior and efficiency of P. aeruginosa in mediated current production is strongly dependent on the strain of P. aeruginosa. We compared levels of phenazine production by the previously investigated model strain P. aeruginosa PA14, the alternative model strain P. aeruginosa PAO1, and the BES isolate Pseudomonas sp. strain KRP1 with glucose and the fermentation products 2,3-butanediol and ethanol as carbon substrates. We found significant differences in substrate-dependent phenazine production and resulting anodic current generation for the three strains, with the BES isolate KRP1 being overall the best current producer and showing the highest electrochemical activity with glucose as a substrate (19 μA cm−2 with ∼150 μg ml−1 phenazine carboxylic acid as a redox mediator). Surprisingly, P. aeruginosa PAO1 showed very low phenazine production and electrochemical activity under all tested conditions. IMPORTANCE Microbial fuel cells and other microbial bioelectrochemical systems hold great promise for environmental technologies such as wastewater treatment and bioremediation. While there is much emphasis on the development of materials and devices to realize such systems, the investigation and a deeper understanding of the underlying microbiology and ecology are lagging behind. Physiological investigations focus on microorganisms exhibiting direct electron transfer in pure culture systems. Meanwhile, mediated electron transfer with natural redox compounds produced by, for example, Pseudomonas aeruginosa might enable an entire microbial community to access a solid electrode as an alternative electron acceptor. To better understand the ecological relationships between mediator producers and mediator utilizers, we here present a comparison of the phenazine-dependent electroactivities of three Pseudomonas strains. This work forms the foundation for more complex coculture investigations of mediated electron transfer in microbial fuel cells. PMID:27287325

Analysis of MINIE2013 Explosion Air-Blast Data

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

Schnurr, Julie M.; Rodgers, Arthur J.; Kim, Keehoon

We report analysis of air-blast overpressure measurements from the MINIE2013 explosive experiments. The MINIE2013 experiment involved a series of nearly 70 near-surface (height-ofburst, HOB, ranging from -1 to +4 m) low-yield (W=2-20 kg TNT equivalent) chemical highexplosives tests that were recorded at local distances (230 m – 28.5 km). Many of the W and HOB combinations were repeated, allowing for quantification of the variability in air-blast features and corresponding yield estimates. We measured canonical signal features (peak overpressure, impulse per unit area, and positive pulse duration) from the air-blast data and compared these to existing air-blast models. Peak overpressure measurementsmore » showed good agreement with the models at close ranges but tended to attenuate more rapidly at longer range (~ 1 km), which is likely caused by upward refraction of acoustic waves due to a negative vertical gradient of sound speed. We estimated yields of the MINIE2013 explosions using the Integrated Yield Determination Tool (IYDT). Errors of the estimated yields were on average within 30% of the reported yields, and there were no significant differences in the accuracy of the IYDT predictions grouped by yield. IYDT estimates tend to be lower than ground truth yields, possibly because of reduced overpressure amplitudes by upward refraction. Finally, we report preliminary results on a development of a new parameterized air-blast waveform.« less

Interactions among soil biology, nutrition, and performance of actinorhizal plant species in the H.J. Andrews Experimental Forest of Oregon.

Treesearch

N.S. Rojas; D.A. Perry; C.Y. Li; L.M. Ganio

2002-01-01

The study examined the effect of Frankia, macronutrients, micronutrients, mycorrhizal fungi, and plant-growth-promoting fluorescent Pseudomonas sp. on total biomass, nodule weight, and nitrogen fixation of red aider (Alnus rubra) and snowbrush (Ceanothus velutinus) under greenhouse conditions. The soil...

TRANSITION FROM COMETABOLIC TO GROWTH-LINKED BIODEGRADATION OF VINYL CHLORIDE BY A PSEUDOMONAS SP. ISOLATED ON ETHENE. (R827612E03)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Toxicity of TNT Wastewaters to Aquatic Organisms. Volume 2. Acute Toxicity of Condensate Wastewater and 2,4-Dinitrotoluene

DTIC Science & Technology

1983-03-01

Gambusia affinis (mosquito fish) and reported a 96-hour LC50 of 1180 mg/L. In tests with Daplnia maa (invertebrate) and Scenedesmus sp. (alga), Bringmann...chronic bioassays be performed. )AM Bringmann and Kuhn (1980) evaluated the response of bacteria (Pseudomonas putid, algae ( Scenedesmus quadricauda

Isolation and application of Gordonia sp. JC11 for removal of boat lubricants.

PubMed

Chanthamalee, Jirapat; Luepromchai, Ekawan

2012-01-01

Boat lubricants are continuously released into the marine environment and thereby cause chronic oil pollution. This study aims to isolate lubricant-degrading microorganisms from Thai coastal areas as well as to apply a selected strain for removal of boat lubricants. Ten microorganisms in the genera of Gordonia, Microbacterium, Acinetobacter, Pseudomonas, Brucella, Enterococcus and Candida were initially isolated by crude oil enrichment culture techniques. The lubricant-removal activity of these isolates was investigated with mineral-based lubricants that had been manufactured for the 4-stroke diesel engines of fishing boats. Gordonia sp. JC11, the most effective strain was able to degrade 25-55% of 1,000 mg L(-1) total hydrocarbons in six tested lubricants, while only 0-15% of the lubricants was abiotically removed. The bacterium had many characteristics that promoted lubricant degradation such as hydrocarbon utilization ability, emulsification activity and cell surface hydrophobicity. For bioaugmentation treatment of lubricant contaminated seawater, the inoculum of Gordonia sp. JC11 was prepared by immobilizing the bacterium on polyurethane foam (PUF). PUF-immobilized Gordonia sp. JC11 was able to remove 42-56% of 100-1,000 mg L(-1) waste lubricant No. 2 within 5 days. This lubricant removal efficiency was higher than those of free cells and PUF without bacterial cells. The bioaugmentation treatment significantly increased the number of lubricant-degrading microorganisms in the fishery port seawater microcosm and resulted in rapid removal of waste lubricant No. 2.

The influence of bioaugmentation and biosurfactant addition on bioremediation efficiency of diesel-oil contaminated soil: feasibility during field studies.

PubMed

Szulc, Alicja; Ambrożewicz, Damian; Sydow, Mateusz; Ławniczak, Łukasz; Piotrowska-Cyplik, Agnieszka; Marecik, Roman; Chrzanowski, Łukasz

2014-01-01

The study focused on assessing the influence of bioaugmentation and addition of rhamnolipids on diesel oil biodegradation efficiency during field studies. Initial laboratory studies (measurement of emitted CO2 and dehydrogenase activity) were carried out in order to select the consortium for bioaugmentation as well as to evaluate the most appropriate concentration of rhamnolipids. The selected consortium consisted of following bacterial taxa: Aeromonas hydrophila, Alcaligenes xylosoxidans, Gordonia sp., Pseudomonas fluorescens, Pseudomonas putida, Rhodococcus equi, Stenotrophomonas maltophilia, Xanthomonas sp. It was established that the application of rhamnolipids at 150 mg/kg of soil was most appropriate in terms of dehydrogenase activity. Based on the obtained results, four treatment methods were designed and tested during 365 days of field studies: I) natural attenuation; II) addition of rhamnolipids; III) bioaugmentation; IV) bioaugmentation and addition of rhamnolipids. It was observed that bioaugmentation contributed to the highest diesel oil biodegradation efficiency, whereas the addition of rhamnolipids did not notably influence the treatment process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Existence of a novel enzyme, pyrroloquinoline quinone-dependent polyvinyl alcohol dehydrogenase, in a bacterial symbiont, Pseudomonas sp. strain VM15C.

PubMed Central

Shimao, M; Ninomiya, K; Kuno, O; Kato, N; Sakazawa, C

1986-01-01

A novel enzyme, pyrroloquinoline quinone (PQQ)-dependent polyvinyl alcohol (PVA) dehydrogenase, was found in and partially purified from the membrane fraction of a PVA-degrading symbiont, Pseudomonas sp. strain VM15C. The enzyme required PQQ for PVA dehydrogenation with phenazine methosulfate, phenazine ethosulfate, and 2,6-dichlorophenolindophenol as electron acceptors and did not show PVA oxidase activity leading to H2O2 formation. The enzyme was active toward low-molecular-weight secondary alcohols rather than primary alcohols. A membrane-bound PVA oxidase was also present in cells of VM15C. Although the purified oxidase showed a substrate specificity similar to that of PQQ-dependent PVA dehydrogenase and about threefold-higher PVA-dehydrogenating activity with phenazine methosulfate or phenazine ethosulfate than PVA oxidase activity with H2O2 formation, it was shown that the enzyme does not contain PQQ as the coenzyme, and PQQ did not affect its activity. Incubation of the membrane fraction of cells with PVA caused a reduction in the cytochrome(s) of the fraction. Images PMID:3513704

Methylobacterium sp. resides in unculturable state in potato tissues in vitro and becomes culturable after induction by Pseudomonas fluorescens IMGB163.

PubMed

Podolich, O; Laschevskyy, V; Ovcharenko, L; Kozyrovska, N; Pirttilä, A M

2009-03-01

To induce growth of endophytic bacteria residing in an unculturable state in tissues of in vitro-grown potato plantlets. To isolate and identify the induced bacteria and to localize the strains in tissues of in vitro-grown potato plantlets. The inoculation of in vitro-grown potato plants with Pseudomonas fluorescens IMBG163 led to induction of another bacterium, a pink-pigmented facultative methylotroph that was identified as Methylobacterium sp. using phylogenetic 16S rDNA approach. Two molecular methods were used for localizing methylobacteria in potato plantlets: PCR and in situ hybridization (ISH/FISH). A PCR product specific for the Methylobacterium genus was found in DNA isolated from the surface-sterilized plantlet leaves. Presence of Methylobacterium rRNA was detected by ISH/FISH in leaves and stems of inoculated as well as axenic potato plantlets although the bacterium cannot be isolated from the axenic plants. Methylobacterium sp. resides in unculturable state within tissues of in vitro-grown potato plants and becomes culturable after inoculation with P. fluorescens IMBG163. In order to develop endophytic biofertilizers and biocontrol agents, a detailed knowledge of the life-style of endophytes is essential. To our knowledge, this is the first report on increase of the culturability of endophytes in response to inoculation by nonpathogenic bacteria.

Pseudomonas cichorii as the causal agent of midrib rot, an emerging disease of greenhouse-grown butterhead lettuce in Flanders.

PubMed

Cottyn, Bart; Heylen, Kim; Heyrman, Jeroen; Vanhouteghem, Katrien; Pauwelyn, Ellen; Bleyaert, Peter; Van Vaerenbergh, Johan; Höfte, Monica; De Vos, Paul; Maes, Martine

2009-05-01

Bacterial midrib rot of greenhouse-grown butterhead lettuce (Lactuca sativa L. var. capitata) is an emerging disease in Flanders (Belgium) and fluorescent pseudomonads are suspected to play an important role in the disease. Isolations from infected lettuces, collected from 14 commercial greenhouses in Flanders, yielded 149 isolates that were characterized polyphasically, which included morphological characteristics, pigmentation, pathogenicity tests by both injection and spraying of lettuce, LOPAT characteristics, FAME analysis, BOX-PCR fingerprinting, 16S rRNA and rpoB gene sequencing, as well as DNA-DNA hybridization. Ninety-eight isolates (66%) exhibited a fluorescent pigmentation and were associated with the genus Pseudomonas. Fifty-five of them induced an HR+ (hypersensitive reaction in tobacco leaves) response. The other 43 fluorescent isolates were most probably saprophytic bacteria and about half of them were able to cause rot on potato tuber slices. BOX-PCR genomic fingerprinting was used to assess the genetic diversity of the Pseudomonas midrib rot isolates. The delineated BOX-PCR patterns matched quite well with Pseudomonas morphotypes defined on the basis of colony appearance and variation in fluorescent pigmentation. 16S rRNA and rpoB gene sequence analyses allowed most of the fluorescent isolates to be allocated to Pseudomonas, and they belonged to either the Pseudomonas fluorescens group, Pseudomonas putida group, or the Pseudomonas cichorii/syringae group. In particular, the isolates allocated to this latter group constituted the vast majority of HR+ isolates and were identified as P. cichorii by DNA-DNA hybridization. They were demonstrated by spray-inoculation tests on greenhouse-grown lettuce to induce the midrib rot disease and could be re-isolated from lesions of inoculated plants. Four HR+ non-fluorescent isolates associated with one sample that showed an atypical midrib rot were identified as Dickeya sp.

Arthritis in ducks. I. Aetiology and public health aspects.

PubMed

Bisgaard, M

1981-01-01

A pure culture of potentially pathogenic bacteria was obtained from 90% of 233 joints examined, originating from 232 ducks condemned due to arthritis at slaughter. S. typhi-murium and Staph. aureus were isolated from 61% and 18% of the joints respectively. E. coli was obtained from 6% of the cases, serogroup 078 being most prevalent. E. rhusiopathiae, Y. pseudo-tuberculosis, P. vulgaris, Micrococcus sp., Streptococcus sp., Acinetobacter sp., Flavobacterium sp., Pseudomonas sp. and Ae. formicans made up 12 cases. Serotypes other than S. typhi-murium were prevalent among ducks from all farms investigated, but S. typhi-murium was the only serotype demonstrated in arthritis. A high incidence of S. typhi-murium in the intestinal tract of ducks maintained on free range or in open houses suggests that these sites are sources of infection and that the intestinal tract is the portal of entry for S. typhi-murium causing arthritis. Ducks with arthritis at slaughter should always be totally condemned because of the public health hazard from the organisms most often associated with this condition.

Investigation of Arsenotrophic Microbiome in Arsenic-Affected Bangladesh Groundwater.

PubMed

Sultana, Munawar; Mou, Taslin Jahan; Sanyal, Santonu Kumar; Diba, Farzana; Mahmud, Zahid Hayat; Parvez, Anowar Khasru; Hossain, M Anwar

2017-09-01

Arsenotrophic bacteria contribute to the nutrient cycling in arsenic (As) affected groundwater. This study employed a culture-independent and -dependent investigation of arsenotrophic microbiomes in As affected groundwater samples collected from Madhabpur, Sonatengra, and Union Porishod in Singair Upazila, Manikganj, Bangladesh. Total As contents, detected by Atomic Absorption Spectrophotometry (AAS) of the samples, were 47 µg/L (Madhabpur, SNGW-1), 53 µg/L (Sonatengra, SNGW-2), and 12 µg/L (Union porishod, SNGW-3), whereas the control well (SNGW-4; depths >150 m) showed As content of 6 µg/L. Denaturing Gradient Gel Electrophoresis (DGGE) analysis of the amplified 16S rRNA gene from As-affected groundwater samples revealed the dominance of aerobic bacteria Pseudomonas within heterogeneous bacterial populations. DGGE of heterotrophic enrichments supplemented with arsenite [As (III)] for 4 weeks showed the dominance of Chryseobacterium, Flavobacterium, and Aquabacterium, whereas the dominant genera in that of autotrophic enrichments were Aeromonas, Acinetobacter, and Pseudomonas. Cultured bacteria retrieved from both autotrophic and heterotrophic enrichments were distinguished into nine genotypes belonging to Chryseobacterium, Acinetobacter, Escherichia, Pseudomonas, Stenotrophomonas, Janibacter, Staphylococcus, and Bacillus. They exhibited varying range of As(III) tolerance from 4 to 27 mM. As(III) transformation potential was confirmed within the isolates with oxidation rate as high as 0.143 mM/h for Pseudomonas sp. Sn 28. The arsenotrophic microbiome specifies their potential role in groundwater As-cycling and their genetic information provide the scientific basis for As-bioremediation. © 2017, National Ground Water Association.

Microbial activity of trench leachates from shallow-land, low-level radioactive waste disposal sites.

PubMed Central

Francis, A J; Dobbs, S; Nine, B J

1980-01-01

Trench leachate samples collected anoxically from shallow-land, low-level radioactive waste disposal sites were analyzed for total aerobic and anaerobic populations, sulfate reducers, denitrifiers, and methanogens. Among the several aerobic and anaerobic bacteria isolated, only Bacillus sp., Pseudomonas sp., Citrobacter sp., and Clostridium sp. were identified. Mixed bacterial cultures isolated from the trench leachates were able to grow anaerobically in trench leachates, which indicates that the radionuclides and organic chemicals present were not toxic to these bacteria. Changes in concentrations of several of the organic constituents of the waste leachate samples were observed due to anaerobic microbial activity. Growth of a mixed culture of trench-water bacteria in media containing a mixture of radionuclides, 60Co, 85Sr, and 134,137Cs, was not affected at total activity concentrations of 2.6 X 10(2) and 2.7 X 10(3) pCi/ml. PMID:7406490

Colonization and Maize Growth Promotion Induced by Phosphate Solubilizing Bacterial Isolates.

PubMed

Li, Yongbin; Liu, Xiaomeng; Hao, Tianyi; Chen, Sanfeng

2017-06-29

Phosphorus (P) limits the production of maize, one of the major food crops in China. Phosphate-solubilizing bacteria (PSB) have the capacity to solubilize phosphate complexes into plant absorbable and utilizable forms by the process of acidification, chelation, and exchange reactions. In this study, six bacteria, including one Paenibacillus sp. B1 strain, four Pseudomonas sp. strains (B10, B14, SX1, and SX2) and one Sphingobium sp. SX14 strain, were those isolated from the maize rhizosphere and identified based on their 16S rRNA sequences. All strains could solubilize inorganic P (Ca₃(PO₄)₂, FePO₄ and AlPO₄), and only B1 and B10 organic P (lecithin). All strains, except of SX1, produced IAA, and SX14 and B1 showed the highest level. B1 incited the highest increase in root length and the second increase in shoot and total dry weight, shoot length, and total P and nitrogen (N), along with increased root length. In addition, by confocal laser scanning microscopy (CLSM), we found that green fluorescent protein (GFP)-labeled B1 mainly colonized root surfaces and in epidermal and cortical tissue. Importantly, B1 can survive through forming spores under adverse conditions and prolong quality guarantee period of bio-fertilizer. Therefore, it can act as a good substitute for bio-fertilizer to promote agricultural sustainability.

Oily wastewaters treatment using Pseudomonas sp. isolated from the compost fertilizer

PubMed Central

2014-01-01

Background Discharging the oily wastewater in the environment causes serious problems, because of the oil compounds and organic materials presence. Applying biological methods using the lipase enzyme producer microorganisms can be an appropriate choice for treatment of these wastewaters. The aim of this study is to treat those oil wastewaters having high concentration of oil by applying lipase enzyme producer bacteria. Materials and methods Oil concentration measurement was conducted using the standard method of gravimetric and the wastewater under study was synthetically made and contained olive, canola and sunflower oil. The strain used in this study was Pseudomonas strain isolated from compost fertilizer. The oil under study had concentration of 1.5 to 22 g/l. Results The oil removal amount in concentrations lower than 8.4 g/l was over 95 ± 1.5%. Increase of the oil's concentration to 22 g/l decreases the amount of removal in retention time of 44 hours to 85 ± 2.5%. The best yield of removing this strain in retention time of 44 hours and temperature of 30°C was achieved using Ammonium Nitrate as the nitrogen resource which yield was about 95 percent. Conclusion The findings of the research showed that Pseudomonas bacteria isolated from the compost fertilizer can degrade high concentration oils. PMID:24876932

Transition to Double Mach Stem for Nuclear Explosion at 104 ft Height of Burst.

DTIC Science & Technology

1981-11-17

P ROIS, 0 L BOOK UNCLASS II D NP.l--4630Mhhnnmmmnmhunm *uunummmummuuuu EllllIhllllllIIIIIIIII VA . L, BOK -- Wotk~ ~ ~ hit ftIlum Zsm Noe4be 01 NOV1...resolved on the mesh. By the time it occupies a region of 15 cells high and 35 cells wide, the peak pressures are in good agreement with the HE data and...2800 3220 2800 32 RADIUS- cm RADIUS -cm 35 1 kt AT 104 f t HOB TIME =5.47 nisec CYCLE= 5400 PRESSURE VELOC IT Y 350

Determination of antimicrobial and heavy metal resistance profiles of some bacteria isolated from aquatic amphibian and reptile species.

PubMed

Hacioglu, Nurcihan; Tosunoglu, Murat

2014-01-01

The aim of the present study was to determine the level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from aquatic animals (Lissotriton vulgaris, Pelophylax ridibundus, Emys orbicularis, Mauremys rivulata, and Natrix natrix) in Turkey (Kavak Delta). A total of 153 bacteria have been successfully isolated from cloaca and oral samples of the aquatic amphibians and reptilians which were found, namely, Aeromonas sp. (n = 29), Plesiomonas sp. (n = 7), Vibrio sp. (n = 12), Citrobacter sp. (n = 12), Enterobacter sp. (n = 11), Escherichia sp. (n = 22), Klebsiella sp. (n = 22), Edwardsiella sp. (n = 6), Hafnia sp. (n = 1), Proteus sp. (n = 19), Providencia sp. (n = 8), and Pseudomonas sp. (n = 4). In terms of antibiotic and heavy metal susceptibility testing, each isolate was tested against 12 antibiotics and 4 metals. There was a high incidence of resistance to cefoxitin (46.40 %), ampicillin (44.44 %), erythromycin (35.29 %), and a low incidence of resistance to gentamicin (6.53 %), kanamycin (8.49 %), chloramphenicol (9.15 %), and cefotaxime (10.45 %). The multiple antibiotic resistance index of each bacterial species indicated that bacteria from raised amphibians and reptiles have been exposed to tested antibiotics, with results ranging from 0 to 0.58. Most isolates showed tolerance to different concentrations of heavy metals, and minimal inhibition concentrations ranged from100 to >3,200 μg/mL. According to these results, a significant occurrence of bacteria in the internal organs of reptiles and amphibians, with a high incidence of resistance against antibiotics and heavy metals, may risk aquatic animals and the public health. These data appoint the importance of epidemiological surveillance and microbiological monitoring and reinforce the need to implement environment protection programs for amphibian and reptile species.

Biomass, gas exchange, and nutrient contents in upland rice plants affected by application forms of microorganism growth promoters.

PubMed

Nascente, Adriano Stephan; de Filippi, Marta Cristina Corsi; Lanna, Anna Cristina; de Souza, Alan Carlos Alves; da Silva Lobo, Valácia Lemes; da Silva, Gisele Barata

2017-01-01

Microorganisms are considered a genetic resource with great potential for achieving sustainable development of agricultural areas. The objective of this research was to determine the effect of microorganism application forms on the production of biomass, gas exchange, and nutrient content in upland rice. The experiment was conducted under greenhouse conditions in a completely randomized design in a factorial 7 × 3 + 1, with four replications. The treatments consisted of combining seven microorganisms with three application forms (microbiolized seed; microbiolized seed + soil drenched with a microorganism suspension at 7 and 15 days after sowing (DAS); and microbiolized seed + plant sprayed with a microorganism suspension at 7 and 15 DAS) and a control (water). Treatments with Serratia sp. (BRM32114), Bacillus sp. (BRM32110 and BRM32109), and Trichoderma asperellum pool provided, on average, the highest photosynthetic rate values and dry matter biomass of rice shoots. Plants treated with Burkolderia sp. (BRM32113), Serratia sp. (BRM32114), and Pseudomonas sp. (BRM32111 and BRM32112) led to the greatest nutrient uptake by rice shoots. Serratia sp. (BRM 32114) was the most effective for promoting an increase in the photosynthetic rate, and for the greatest accumulation of nutrients and dry matter at 84 DAS, in rice shoots, which differed from the control treatment. The use of microorganisms can bring numerous benefits of rice, such as improving physiological characteristics, nutrient uptake, biomass production, and grain yield.

Shifts in spinach microbial communities after chlorine washing and storage at compliant and abusive temperatures.

PubMed

Gu, Ganyu; Ottesen, Andrea; Bolten, Samantha; Ramachandran, Padmini; Reed, Elizabeth; Rideout, Steve; Luo, Yaguang; Patel, Jitendra; Brown, Eric; Nou, Xiangwu

2018-08-01

Fresh produce, like spinach, harbors diverse bacterial populations, including spoilage and potentially pathogenic bacteria. This study examined the effects of produce washing in chlorinated water and subsequent storage on the microbiota of spinach. Baby spinach leaves from a commercial fresh-cut produce processor were assessed before and after washing in chlorinated water, and then after one week's storage at 4, 10, and 15 °C. Microbial communities on spinach were analyzed by non-selective plating, qPCR, and 16S rDNA amplicon sequencing. Bacterial populations on spinach, averaging 6.12 ± 0.61 log CFU/g, were reduced by 1.33 ± 0.57 log after washing. However, populations increased by 1.77-3.24 log after storage, with larger increases occurring at higher temperature (15 > 10 > 4 °C). The predominant phylum identified on unwashed spinach leaves was Proteobacteria; dominant genera were Pseudomonas and Sphingomonas. Bacterial communities shifted significantly after chlorine washing and storage. Several Proteobacteria species, such as Stenotrophomonas sp. and Erwinia sp., were relatively tolerant of chlorine treatment, while species of Flavobacterium and Pedobacter (phylum Bacteroidetes) grew rapidly during storage, especially at abusive temperatures. Cupriavidus sp. and Ralstonia sp. showed significant increases after washing. After storage, microbial communities on spinach appeared to shift back toward the pre-washing distributions. Copyright © 2018. Published by Elsevier Ltd.

Resisting majesty: Apis cerana, has lower antennal sensitivity and decreased attraction to queen mandibular pheromone than Apis mellifera

NASA Astrophysics Data System (ADS)

Dong, Shihao; Wen, Ping; Zhang, Qi; Li, Xinyu; Tan, Ken; Nieh, James

2017-03-01

In highly social bees, queen mandibular pheromone (QMP) is vital for colony life. Both Apis cerana (Ac) and Apis mellifera (Am) share an evolutionarily conserved set of QMP compounds: (E)-9-oxodec-2-enoic acid (9-ODA), (E)-9-hydroxydec-2-enoic acid (9-HDA), (E)-10-hydroxy-dec-2-enoic acid (10-HDA), 10-hydroxy-decanoic acid (10-HDAA), and methyl p-hydroxybenzoate (HOB) found at similar levels. However, evidence suggests there may be species-specific sensitivity differences to QMP compounds because Ac workers have higher levels of ovarian activation than Am workers. Using electroantennograms, we found species-specific sensitivity differences for a blend of the major QMP compounds and three individual compounds (9-HDA, 10-HDAA, and 10-HDA). As predicted, Am was more sensitive than Ac in all cases (1.3- to 2.7- fold higher responses). There were also species differences in worker retinue attraction to three compounds (9-HDA, HOB, and 10-HDA). In all significantly different cases, Am workers were 4.5- to 6.2-fold more strongly attracted than Ac workers were. Thus, Ac workers responded less strongly to QMP than Ac workers, and 9-HDA and 10-HDA consistently elicited stronger antennal and retinue formation responses.

Resisting majesty: Apis cerana, has lower antennal sensitivity and decreased attraction to queen mandibular pheromone than Apis mellifera.

PubMed

Dong, Shihao; Wen, Ping; Zhang, Qi; Li, Xinyu; Tan, Ken; Nieh, James

2017-03-15

In highly social bees, queen mandibular pheromone (QMP) is vital for colony life. Both Apis cerana (Ac) and Apis mellifera (Am) share an evolutionarily conserved set of QMP compounds: (E)-9-oxodec-2-enoic acid (9-ODA), (E)-9-hydroxydec-2-enoic acid (9-HDA), (E)-10-hydroxy-dec-2-enoic acid (10-HDA), 10-hydroxy-decanoic acid (10-HDAA), and methyl p-hydroxybenzoate (HOB) found at similar levels. However, evidence suggests there may be species-specific sensitivity differences to QMP compounds because Ac workers have higher levels of ovarian activation than Am workers. Using electroantennograms, we found species-specific sensitivity differences for a blend of the major QMP compounds and three individual compounds (9-HDA, 10-HDAA, and 10-HDA). As predicted, Am was more sensitive than Ac in all cases (1.3- to 2.7- fold higher responses). There were also species differences in worker retinue attraction to three compounds (9-HDA, HOB, and 10-HDA). In all significantly different cases, Am workers were 4.5- to 6.2-fold more strongly attracted than Ac workers were. Thus, Ac workers responded less strongly to QMP than Am workers, and 9-HDA and 10-HDA consistently elicited stronger antennal and retinue formation responses [corrected].

Limazepines A-F, pyrrolo[1,4]benzodiazepine Antibiotics from an Indonesian Micrococcus sp.

PubMed

Fotso, Serge; Zabriskie, T Mark; Proteau, Philip J; Flatt, Patricia M; Santosa, Dwi Andreas; Mahmud, Taifo

2009-04-01

In our screening of Indonesian microorganisms for novel bioactive natural products we have isolated seven new compounds, designated as limazepines A, B1 and B2 (isolated as an isomeric mixture), C, D, E, and F, from the culture broth of Micrococcus sp. strain ICBB 8177. In addition, the known natural products prothracarcin and 7-O-succinylmacrolactin A, as well as two previously reported synthetic compounds, 2-amino-3-hydroxy-4-methoxybenzoic acid methyl ester and 4-ethylpyrrole-2-carboxaldehyde, were obtained from the extract. Chemical structures were determined by spectroscopic methods and by comparison with the NMR data of structurally related compounds. The limazepines belong to the growing group of the pyrrolo[1,4]benzodiazepine antitumor antibiotics isolated from various soil bacteria. Limazepines B1/B2 mixture, C, and E were active against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacterium Escherichia coli. Limazepine D was also active against S. aureus, but was not active against E. coli. Interestingly, only the limazepines B1/B2 mixture and D were active against Pseudomonas aeruginosa.

Efflux pump-deficient mutants as a platform to search for microbes that produce antibiotics.

PubMed

Molina-Santiago, Carlos; Udaondo, Zulema; Daddaoua, Abdelali; Roca, Amalia; Martín, Jesús; Pérez-Victoria, Ignacio; Reyes, Fernando; Ramos, Juan-Luis

2015-07-01

Pseudomonas putida DOT-T1E-18 is a strain deficient in the major antibiotic efflux pump (TtgABC) that exhibits an overall increased susceptibility to a wide range of drugs when compared with the wild-type strain. We used this strain as a platform to search for microbes able to produce antibiotics that inhibit growth. A collection of 2400 isolates from soil, sediments and water was generated and a drop assay developed to identify, via growth inhibition halos, strains that prevent the growth of DOT-T1E-18 on solid Luria-Bertani plates. In this study, 35 different isolates that produced known and unknown antibiotics were identified. The most potent inhibitor of DOT-T1E-18 growth was an isolate named 250J that, through multi-locus sequence analysis, was identified as a Pseudomonas sp. strain. Culture supernatants of 250J contain four different xantholysins that prevent growth of Gram-positive bacteria, Gram-negative and fungi. Two of the xantholysins were produced in higher concentrations and purified. Xantholysin A was effective against Bacillus, Lysinibacillus and Rhodococcus strains, and the effect against these microbes was enhanced when used in combination with other antibiotics such as ampicillin, gentamicin and kanamycin. Xantholysin C was also efficient against Gram-positive bacteria and showed an interesting antimicrobial effect against Pseudomonas strains, and a synergistic inhibitory effect with ampicillin, chloramphenicol and gentamicin. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Aerobic Degradation of N-Methyl-4-Nitroaniline (MNA) by Pseudomonas sp. Strain FK357 Isolated from Soil

PubMed Central

Khan, Fazlurrahman; Vyas, Bhawna; Pal, Deepika; Cameotra, Swaranjit Singh

2013-01-01

N-Methyl-4-nitroaniline (MNA) is used as an additive to lower the melting temperature of energetic materials in the synthesis of insensitive explosives. Although the biotransformation of MNA under anaerobic condition has been reported, its aerobic microbial degradation has not been documented yet. A soil microcosms study showed the efficient aerobic degradation of MNA by the inhabitant soil microorganisms. An aerobic bacterium, Pseudomonas sp. strain FK357, able to utilize MNA as the sole carbon, nitrogen, and energy source, was isolated from soil microcosms. HPLC and GC-MS analysis of the samples obtained from growth and resting cell studies showed the formation of 4-nitroaniline (4-NA), 4-aminophenol (4-AP), and 1, 2, 4-benzenetriol (BT) as major metabolic intermediates in the MNA degradation pathway. Enzymatic assay carried out on cell-free lysates of MNA grown cells confirmed N-demethylation reaction is the first step of MNA degradation with the formation of 4-NA and formaldehyde products. Flavin-dependent transformation of 4-NA to 4-AP in cell extracts demonstrated that the second step of MNA degradation is a monooxygenation. Furthermore, conversion of 4-AP to BT by MNA grown cells indicates the involvement of oxidative deamination (release of NH2 substituent) reaction in third step of MNA degradation. Subsequent degradation of BT occurs by the action of benzenetriol 1, 2-dioxygenase as reported for the degradation of 4-nitrophenol. This is the first report on aerobic degradation of MNA by a single bacterium along with elucidation of metabolic pathway. PMID:24116023

Aerobic degradation of N-methyl-4-nitroaniline (MNA) by Pseudomonas sp. strain FK357 isolated from soil.

PubMed

Khan, Fazlurrahman; Vyas, Bhawna; Pal, Deepika; Cameotra, Swaranjit Singh

2013-01-01

N-Methyl-4-nitroaniline (MNA) is used as an additive to lower the melting temperature of energetic materials in the synthesis of insensitive explosives. Although the biotransformation of MNA under anaerobic condition has been reported, its aerobic microbial degradation has not been documented yet. A soil microcosms study showed the efficient aerobic degradation of MNA by the inhabitant soil microorganisms. An aerobic bacterium, Pseudomonas sp. strain FK357, able to utilize MNA as the sole carbon, nitrogen, and energy source, was isolated from soil microcosms. HPLC and GC-MS analysis of the samples obtained from growth and resting cell studies showed the formation of 4-nitroaniline (4-NA), 4-aminophenol (4-AP), and 1, 2, 4-benzenetriol (BT) as major metabolic intermediates in the MNA degradation pathway. Enzymatic assay carried out on cell-free lysates of MNA grown cells confirmed N-demethylation reaction is the first step of MNA degradation with the formation of 4-NA and formaldehyde products. Flavin-dependent transformation of 4-NA to 4-AP in cell extracts demonstrated that the second step of MNA degradation is a monooxygenation. Furthermore, conversion of 4-AP to BT by MNA grown cells indicates the involvement of oxidative deamination (release of NH2 substituent) reaction in third step of MNA degradation. Subsequent degradation of BT occurs by the action of benzenetriol 1, 2-dioxygenase as reported for the degradation of 4-nitrophenol. This is the first report on aerobic degradation of MNA by a single bacterium along with elucidation of metabolic pathway.

Effects of medium and trace metals on kinetics of carbon tetrachloride transformation by Pseudomonas sp. strain KC.

PubMed Central

Tatara, G M; Dybas, M J; Criddle, C S

1993-01-01

Under denitrifying conditions, Pseudomonas sp. strain KC transforms carbon tetrachloride (CT) to carbon dioxide via a complex but as yet undetermined mechanism. Transformation rates were first order with respect to CT concentration over the CT concentration range examined (0 to 100 micrograms/liter) and proportional to protein concentration, giving pseudo-second-order kinetics overall. Addition of ferric iron (1 to 20 microM) to an actively transforming culture inhibited CT transformation, and the degree of inhibition increased with increasing iron concentration. By removing iron from the trace metals solution or by removing iron-containing precipitate from the growth medium, higher second-order rate coefficients were obtained. Copper also plays a role in CT transformation. Copper was toxic at neutral pH. By adjusting the medium pH to 8.2, soluble iron and copper levels decreased as a precipitate formed, and CT transformation rates increased. However, cultures grown at high pH without any added trace copper (1 microM) exhibited slower growth rates and greatly reduced rates of CT transformation, indicating that copper is required for CT transformation. The use of pH adjustment to decrease iron solubility, to avoid copper toxicity, and to provide a selective advantage for strain KC was evaluated by using soil slurries and groundwater containing high levels of iron. In samples adjusted to pH 8.2 and inoculated with strain KC, CT disappeared rapidly in the absence or presence of acetate or nitrate supplements. CT did not disappear in pH-adjusted controls that were not inoculated with strain KC. PMID:8357248

Does S-Metolachlor Affect the Performance of Pseudomonas sp. Strain ADP as Bioaugmentation Bacterium for Atrazine-Contaminated Soils?

PubMed Central

Viegas, Cristina A.; Costa, Catarina; André, Sandra; Viana, Paula; Ribeiro, Rui; Moreira-Santos, Matilde

2012-01-01

Atrazine (ATZ) and S-metolachlor (S-MET) are two herbicides widely used, often as mixtures. The present work examined whether the presence of S-MET affects the ATZ-biodegradation activity of the bioaugmentation bacterium Pseudomonas sp. strain ADP in a crop soil. S-MET concentrations were selected for their relevance in worst-case scenarios of soil contamination by a commercial formulation containing both herbicides. At concentrations representative of application of high doses of the formulation (up to 50 µg g−1 of soil, corresponding to a dose approximately 50× higher than the recommended field dose (RD)), the presence of pure S-MET significantly affected neither bacteria survival (∼107 initial viable cells g−1 of soil) nor its ATZ-mineralization activity. Consistently, biodegradation experiments, in larger soil microcosms spiked with 20× or 50×RD of the double formulation and inoculated with the bacterium, revealed ATZ to be rapidly (in up to 5 days) and extensively (>96%) removed from the soil. During the 5 days, concentration of S-MET decreased moderately to about 60% of the initial, both in inoculated and non-inoculated microcosms. Concomitantly, an accumulation of the two metabolites S-MET ethanesulfonic acid and S-MET oxanilic acid was found. Despite the dissipation of almost all the ATZ from the treated soils, the respective eluates were still highly toxic to an aquatic microalgae species, being as toxic as those from the untreated soil. We suggest that this high toxicity may be due to the S-MET and/or its metabolites remaining in the soil. PMID:22615921

Promotion of arsenic phytoextraction efficiency in the fern Pteris vittata by the inoculation of As-resistant bacteria: a soil bioremediation perspective

PubMed Central

Lampis, Silvia; Santi, Chiara; Ciurli, Adriana; Andreolli, Marco; Vallini, Giovanni

2015-01-01

A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: (i) non-inoculated plants; (ii) plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A); (iii) plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4, and Pseudoxanthomonas sp. P4V6 (B), and (iv) plants inoculated with all five bacterial strains (AB). The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community. PMID:25741356

Comparison of plant growth-promotion with Pseudomonas aeruginosa and Bacillus subtilis in three vegetables

PubMed Central

Adesemoye, A.O.; Obini, M.; Ugoji, E.O.

2008-01-01

Our objective was to compare some plant growth promoting rhizobacteria (PGPR) properties of Bacillus subtilis and Pseudomonas aeruginosa as representatives of their two genera. Solanum lycopersicum L. (tomato), Abelmoschus esculentus (okra), and Amaranthus sp. (African spinach) were inoculated with the bacterial cultures. At 60 days after planting, dry biomass for plants treated with B. subtilis and P. aeruginosa increased 31% for tomato, 36% and 29% for okra, and 83% and 40% for African spinach respectively over the non-bacterized control. Considering all the parameters tested, there were similarities but no significant difference at P < 0.05 between the overall performances of the two organisms. PMID:24031240

Disease protection and allelopathic interactions of seed-transmitted endophytic pseudomonads of invasive reed grass (Phragmites australis)

USGS Publications Warehouse

White, James F.; Kingsley, Katheryn I; Kowalski, Kurt P.; Irizarry, Ivelisse; Micci, April; Soares, Marcos Antonio; Bergen, Marshall S.

2018-01-01

Background and aimsNon-native Phragmites australis (haplotype M) is an invasive grass that decreases biodiversity and produces dense stands. We hypothesized that seeds of Phragmites carry microbes that improve seedling growth, defend against pathogens and maximize capacity of seedlings to compete with other plants.MethodsWe isolated bacteria from seeds of Phragmites, then evaluated representatives for their capacities to become intracellular in root cells, and their effects on: 1.) germination rates and seedling growth, 2.) susceptibility to damping-off disease, and 3.) mortality and growth of competitor plant seedlings (dandelion (Taraxacum officionale F. H. Wigg) and curly dock (Rumex crispus L.)).ResultsTen strains (of 23 total) were identified and characterized; seven were identified as Pseudomonas spp. Strains Sandy LB4 (Pseudomonas fluorescens) and West 9 (Pseudomonas sp.) entered root meristems and became intracellular. These bacteria improved seed germination in Phragmites and increased seedling root branching in Poa annua. They increased plant growth and protected plants from damping off disease. Sandy LB4 increased mortality and reduced growth rates in seedlings of dandelion and curly dock.ConclusionsPhragmites plants associate with endophytes to increase growth and disease resistance, and release bacteria into the soil to create an environment that is favorable to their seedlings and less favorable to competitor plants.

IDENTIFICATION OF BACTERIA IN BLOOD CULTURES FROM CLINICALLY ILL CAPTIVE ANTILLEAN MANATEES (TRICHECHUS MANATUS MANATUS).

PubMed

Silva, Mariana C O; Attademo, Fernanda F L; Freire, Augusto C B; Sousa, Glaucia P; Luna, Fábia O; Lima, Débora C V; Mota, Rinaldo A; Mendes, Emiko S; Silva, Jean C R

2017-03-01

Between September 2001 and March 2013, 62 bacterial cultures (37 aerobic and 25 anaerobic) were performed on 37 blood samples from 23 Antillean manatees ( Trichechus manatus manatus) that were kept in captivity at the Brazilian National Center for Research and Conservation of Aquatic Mammals (CMA) in Pernambuco (CMA-PE) and Alagoas (CMA-AL), Brazil. All of the animals sampled exhibited clinical signs at the time of sampling including abscesses (n = 8), debilitation and anorexia (n = 22), and profound lethargy-moribundity (n = 7). The 4 animals with profound lethargy-moribundity died shortly after sampling of unknown causes. Bacteria were isolated from 15/37 (40.5%) and aerobic blood cultures from 13/23 animals (56.5%). None of the anaerobic cultures were positive. Aeromonas caviae , Aeromonas hydrophila , Aeromonas sp., Escherichia coli , Leclercia adecarboxylata , Pantoea agglomerans , Pseudomonas aeruginosa , Pseudomonas stutzeri , Pseudomonas sp., Sphingomonas paucimobilis , coagulase-negative Staphylococcus, and Staphylococcus epidermidis were each found in only one animal; Staphylococcus spp. was found in two; and Vibrio fluvialis in four. Thirteen samples had only one bacteria isolated, one sample had two bacteria, and one sample had three bacteria isolated. Regarding sex, age group, and origin among the manatees examined, 54.5% (6/11) of the females, 58.3% (7/12) of the males, 40% (2/5) of the calves, 66.7% (8/12) of the juveniles, 50% (3/6) of the adults, 55.5% (10/18) at CMA-PE, and 60% (3/5) at CMA-AL were found to be positive for bacterial growth during at least one sampling time. All Antillean manatees were clinically ill. Regarding clinical signs, bacteria were found in 50% (11/22) of blood samples of the animals showing debilitation and anorexia, 1 of 8 (12.5%) of blood samples of the animals showing abscesses, and 3 of 7 (42.9%) of blood samples of the animals showing profound lethargy-moribundity.

Identification of the potential of microbial combinations obtained from spent mushroom cultivation substrates for use in textile effluent decolorization.

PubMed

Singh, Rajender; Ahlawat, O P; Rajor, Anita

2012-12-01

The study presents variation in microbial population of Agaricus bisporus, Pleurotus sajor-caju and Volvariella volvacea spent substrates (SMS) along with ligninolytic enzymes activity and textile effluent decolorization potential of microorganisms isolated from these. The effect of temperature, pH, carbon sources and immobilizing agents on effluent decolorization using different combinations of these microorganisms has also been studied. SMS of P. sajor-caju harbored highest population and diversity of bacteria and fungi compared to other SMSs. Schizophyllum commune and Pezizomycotina sp. from P. sajor-caju SMS, exhibited highest activities of laccase (11.8 and 8.32U mL(-1)) and lignin peroxidase (339 and 318 UL(-1)), while Pseudomonas fluorescens of Manganese peroxidase. Highest decolorization was in presence of glucose and sucrose at 30°C, and microbial consortium comprised of the immobilized forms of S. commune and Pezizomycotina sp. on wheat straw and broth cultures of P. fluorescens, Bacillus licheniformis and Bacillus pumilus. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of cadmium on lake water bacteria as determined by the luciferase assay of adenosine triphosphate

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

Seyfried, P.L.; Horgan, C.B.L.

1981-10-01

A firefly luciferase assay of bacterial adenosine triphosphate (ATP) was developed to measure the toxic effects of cadmium ions on aquatic organisms. Toxicity was monitored using intracellular (I/C) ATP (in micrograms per litre) as well as plate counts (colony-forming units per millilitre). The bacteria, which belonged mainly to the families Enterobacteriaceae and Pseudomonadaceae, exhibited varying degrees of resistance to up to 100 ppm cadmium when grown in a glucose-salts medium at pH 6.8. Among the organisms tested, cadmium resistance decreased in the following order: Pseudomonas vesicularis > P. aeruginosa > Enterobacter sp. > P. fluorescens > Chromobacter sp. > Serratiamore » sp. A rise in the pH of the growth medium from 5 to 7 resulted in increased toxicity of cadmium.« less

Identification and Antibacterial Activity of Bacteria Isolated from Marine Sponge Haliclona (Reniera) sp. against Multi-Drug Resistant Human Pathogen

NASA Astrophysics Data System (ADS)

Ardhanu Asagabaldan, Meezan; Ayuningrum, D.; Kristiana, R.; Sabdono, A.; Radjasa, O. K.; Trianto, A.

2017-02-01

The marine sponge Haliclona (Reniera) sp. was a potential source of natural bioactive compounds. This sponge widely distributed along the coast of Panjang Island, Jepara, Indonesia. The aims of this research were to isolate the associated bacteria with Haliclona (Reniera) sp. and to screen the antibacterial activity against Multi-Drug Resistant (MDR) bacteria. Amount five bacteria were isolated using media selective for bacteria. The antibacterial activities of bacteria were performed by overlay methods. The bacteria strain PSP. 39-04 had the best activity against Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, and Enterobacter cloaceae. Based on colony morphology and phylogenetic characterization using 16S rRNA gene sequencing, PSP 39-04 was closely related with Chromohalobacter salixigens strain DSM3043.

Synergistic growth studies of Entamoeba gingivalis using an Ecologen.

PubMed

Gannon, J T; Linke, H A

1992-11-01

A unique multiple diffusion growth chamber, an Ecologen, designed for the study of interactions among microorganisms, was introduced as a means of growing xenic cultures of Entamoeba gingivalis with Crithidia sp. or Yersinia enterocolitica. Entamoeba gingivalis was grown in the central diffusion reservoir of the Ecologen connected to separate growth chambers inoculated with the microorganisms to be evaluated. Growth of the accompanying bacteria in the E. gingivalis compartment was almost completely eliminated, except for sparse Pseudomonas sp. growth. The most vital E. gingivalis cultures were observed when either Crithidia sp. or Y. enterocolitica were added to the Ecologen 48 h prior to the E. gingivalis inoculum. The medium which provided the best growth of the oral protozoan in this system was the new improved E. gingivalis medium containing antibiotics.

Staphylococcal scalded skin syndrome in a premature newborn caused by methicillin-resistant Staphylococcus aureus: case report.

PubMed

Hörner, Andreas; Hörner, Rosmari; Salla, Adenilde; Nunes, Melise Silveira; Garzon, Litiérri Razia; Rampelotto, Roberta Filipini; Martini, Rosiéli; Santos, Silvana Oliveira dos; Gindri, Lívia; Rodrigues, Mônica de Abreu; Giacomolli, Cláudia

2015-01-01

Staphylococcal scalded skin syndrome is an exfoliative skin disease. Reports of this syndrome in newborns caused by methicillin-resistant Staphylococcus aureus are rare but, when present, rapid diagnosis and treatment is required in order to decrease morbidity and mortality. A premature newly born girl weighing 1,520 g, born with a gestational age of 29 weeks and 4 days, developed staphylococcal scalded skin syndrome on the fifth day of life. Cultures on blood samples collected on the first and fourth days were negative, but Pseudomonas aeruginosa and Enterococcus sp. (vancomycin-sensitive) developed in blood cultures performed on the day of death (seventh day), and Pseudomonas aeruginosa and Serratia marcescens were identified in cultures on nasopharyngeal, buttock and abdominal secretions. In addition to these two Gram-negative bacilli, methicillin-resistant Staphylococcus aureus was isolated in a culture on the umbilical stump (seventh day). The diagnosis of staphylococcal scalded skin syndrome was based on clinical criteria.

Decaffeination and measurement of caffeine content by addicted Escherichia coli with a refactored N-demethylation operon from Pseudomonas putida CBB5.

PubMed

Quandt, Erik M; Hammerling, Michael J; Summers, Ryan M; Otoupal, Peter B; Slater, Ben; Alnahhas, Razan N; Dasgupta, Aurko; Bachman, James L; Subramanian, Mani V; Barrick, Jeffrey E

2013-06-21

The widespread use of caffeine (1,3,7-trimethylxanthine) and other methylxanthines in beverages and pharmaceuticals has led to significant environmental pollution. We have developed a portable caffeine degradation operon by refactoring the alkylxanthine degradation (Alx) gene cluster from Pseudomonas putida CBB5 to function in Escherichia coli. In the process, we discovered that adding a glutathione S-transferase from Janthinobacterium sp. Marseille was necessary to achieve N 7 -demethylation activity. E. coli cells with the synthetic operon degrade caffeine to the guanine precursor, xanthine. Cells deficient in de novo guanine biosynthesis that contain the refactored operon are ″addicted″ to caffeine: their growth density is limited by the availability of caffeine or other xanthines. We show that the addicted strain can be used as a biosensor to measure the caffeine content of common beverages. The synthetic N-demethylation operon could be useful for reclaiming nutrient-rich byproducts of coffee bean processing and for the cost-effective bioproduction of methylxanthine drugs.

Analysis of Substrate Access to Active Sites in Bacterial Multicomponent Monooxygenase Hydroxylases: X-ray Crystal Structure of Xenon-Pressurized Phenol Hydroxylase from Pseudomonas sp. OX1†,‡

PubMed Central

McCormick, Michael S.; Lippard, Stephen J.

2011-01-01

In all structurally characterized bacterial multicomponent monooxygenase (BMM) hydroxylase proteins, a series of hydrophobic cavities in the α-subunit trace a conserved path from the protein exterior to the carboxylate-bridged diiron active site. The present study examines these cavities as a potential route for dioxygen transport to the active site by crystallographic characterization of a xenon-pressurized sample of the hydroxylase component of phenol hydroxylase from Pseudomonas sp. OX1. Computational analyses of the hydrophobic cavities in the hydroxylase α-subunits of phenol hydroxylase (PHH), toluene/o-xylene monooxygenase (ToMOH), and soluble methane monooxygenase (sMMOH) are also presented. The results, together with previous findings from crystallographic studies of xenon-pressurized sMMO hydroxylase, clearly identify the propensity for these cavities to bind hydrophobic gas molecules in the protein interior. This proposed functional role is supported by recent stopped flow kinetic studies of ToMOH variants (Song, et al., 2011). In addition to information about the Xe sites, the structure determination revealed significantly reduced regulatory protein binding to the hydroxylase in comparison to the previously reported structure of PHH, as well as the presence of a newly identified metal binding site in the α-subunit that adopts a linear coordination environment consistent with Cu(I), and a glycerol molecule bound to Fe1 in a fashion that is unique among hydrocarbon-diiron site adducts reported to date in BMM hydroxylase structures. Finally, a comparative analysis of the α-subunit structures of MMOH, ToMOH, and PHH details proposed routes for the other three BMM substrates, the hydrocarbon, electrons, and protons, comprising cavities, channels, hydrogen-bonding networks, and pores in the structures of their α-subunits. PMID:22136180

Effects of Cu2+ and humic acids on degradation and fate of TBBPA in pure culture of Pseudomonas sp. strain CDT.

PubMed

Ma, Yini; Zhao, Yingying; Wang, Yongfeng; Li, Xiangzhen; Sun, Feifei; Corvini, Phillippe Francois-Xavier; Ji, Rong

2017-12-01

Soil contamination with tetrabromobisphenol A (TBBPA) has caused great concerns; however, the presence of heavy metals and soil organic matter on the biodegradation of TBBPA is still unclear. We isolated Pseudomonas sp. strain CDT, a TBBPA-degrading bacterium, from activated sludge and incubated it with 14 C-labeled TBBPA for 87 days in the absence and presence of Cu 2+ and humic acids (HA). TBBPA was degraded to organic-solvent extractable (59.4%±2.2%) and non-extractable (25.1%±1.3%) metabolites, mineralized to CO 2 (4.8%±0.8%), and assimilated into cells (10.6%±0.9%) at the end of incubation. When Cu 2+ was present, the transformation of extractable metabolites into non-extractable metabolites and mineralization were inhibited, possibly due to the toxicity of Cu 2+ to cells. HA significantly inhibited both dissipation and mineralization of TBBPA and altered the fate of TBBPA in the culture by formation of HA-bound residues that amounted to 22.1%±3.7% of the transformed TBBPA. The inhibition from HA was attributed to adsorption of TBBPA and formation of bound residues with HA via reaction of reactive metabolites with HA molecules, which decreased bioavailability of TBBPA and metabolites in the culture. When Cu 2+ and HA were both present, Cu 2+ significantly promoted the HA inhibition on TBBPA dissipation but not on metabolite degradation. The results provide insights into individual and interactive effects of Cu 2+ and soil organic matter on the biotransformation of TBBPA and indicate that soil organic matter plays an essential role in determining the fate of organic pollutants in soil and mitigating heavy metal toxicity. Copyright © 2017. Published by Elsevier B.V.

Sediment-Water Interactions and Contaminants in Corps of Engineers Reservoir Projects

DTIC Science & Technology

1989-07-01

Pseudomonas sp . strain NCIB 9816," Journal of Bacteriology, Vol 149, pp 948-954. Fillos, J., and Molof, A. H. 1972. "The Effect of Benthal Deposits on Oxygen...34Dimethylselenide and Dimethyltelluride Formation by a Strain of Penicillium ," Applied Microbiology, Vol 24, pp 424-429. Francis, A. J., Duxbury, J. M

Inhibition of bacterial growth in sweet cheese whey by carbon dioxide as determined by culture-independent community profiling.

PubMed

Lo, Raquel; Xue, Tian; Weeks, Mike; Turner, Mark S; Bansal, Nidhi

2016-01-18

Whey is a valuable co-product from cheese making that serves as a raw material for a wide range of products. Its rich nutritional content lends itself to rapid spoilage, thus it typically needs to be pasteurised and refrigerated promptly. Despite the extensive literature on milk spoilage bacteria, little is known about the spoilage bacteria of whey. The utility of carbon dioxide (CO2) to extend the shelf-life of raw milk and cottage cheese has been well established, but its application in whey preservation has not yet been explored. This study aims to characterise the microbial populations of fresh and spoiled sweet whey by culture-independent community profiling using 454 pyrosequencing of 16S rRNA gene amplicons and to determine whether carbonation is effective in inhibiting bacterial growth in sweet whey. The microbiota of raw Cheddar and Mozzarella whey was dominated by cheese starter bacteria. After pasteurisation, two out of the three samples studied became dominated by diverse environmental bacteria from various phyla, with Proteobacteria being the most dominant. Diverse microbial profiles were maintained until spoilage occurred, when the entire population was dominated by just one or two genera. Whey spoilage bacteria were found to be similar to those of milk. Pasteurised Cheddar and Mozzarella whey was spoiled by Bacillus sp. or Pseudomonas sp., and raw Mozzarella whey was spoiled by Pseudomonas sp., Serratia sp., and other members of the Enterobacteriaceae family. CO2 was effective in inhibiting bacterial growth of pasteurised Cheddar and Mozzarella whey stored at 15°C and raw Mozzarella whey stored at 4°C. The spoilage bacteria of the carbonated samples were similar to those of the non-carbonated controls. Copyright © 2015 Elsevier B.V. All rights reserved.

Bacterial community structure and diversity in the gut of Muga silkworm, Antheraea assamensis (Lepidoptera: Saturniidae) from India.

PubMed

Gandotra, Sakshi; Kumar, Archna; Naga, Kailash; Bhuyan, Pinky Moni; Gogoi, Dip K; Sharma, Kirti; Subramanian, Sabtharishi

2018-04-17

Muga silkworm, Antheraea assamensis is exclusively present in the North Eastern regions of India and rearing of this silkworm is a vocation unique to this region in the world. Through culture dependent techniques, generic identification using 16s rRNA probes, diversity analysis and qualitative screening for enzyme activities, our studies have identified a number of bacterial isolates viz., Bacillus spp, Serratia marcescens, Stenotrophomonas maltophilia, Pseudomonas stutzeri, Acinetobacter sp. and Alcaligens sp. inhabiting the gut of muga silkworm. Analysis of culturable bacterial community from the gut of A. assamensis revealed that Bacillus (54%) was the predominant bacterial genera followed by Serratia (24%), Pseudomonas (10%) and Alcaligens (6%). Significant differences in Shannon and the Simpson diversity indices of gut bacteria were recorded for A. assamensis collected from different regions. Shannon (H) and Simpson (D) diversity indices were found to be the highest for A. assamensis from Titabar region (H= 4.73 ± 0.43), (D= 10.00 ± 0.11) and the lowest for Mendipathar region (H= 2.1 ± 0.05), (D= 0.04 ± 0.00) respectively of North Eastern India. Qualitative screening for enzymatic activities identified a number of gut bacterial isolates having significantly higher cellulose, amylase, lipase activities which may probably be contributing to the digestion and nutrition of their host insect, A. assamensis. This article is protected by copyright. All rights reserved. © 2018 The Royal Entomological Society.

An Enterotoxin-Like Binary Protein from Pseudomonas protegens with Potent Nematicidal Activity.

PubMed

Wei, Jun-Zhi; Siehl, Daniel L; Hou, Zhenglin; Rosen, Barbara; Oral, Jarred; Taylor, Christopher G; Wu, Gusui

2017-10-01

Soil microbes are a major food source for free-living soil nematodes. It is known that certain soil bacteria have evolved systems to combat predation. We identified the nematode-antagonistic Pseudomonas protegens strain 15G2 from screening of microbes. Through protein purification we identified a binary protein, designated Pp-ANP, which is responsible for the nematicidal activity. This binary protein inhibits Caenorhabditis elegans growth and development by arresting larvae at the L1 stage and killing older-staged worms. The two subunits, Pp-ANP1a and Pp-ANP2a, are active when reconstituted from separate expression in Escherichia coli The binary toxin also shows strong nematicidal activity against three other free-living nematodes ( Pristionchus pacificus , Panagrellus redivivus , and Acrobeloides sp.), but we did not find any activity against insects and fungi under test conditions, indicating specificity for nematodes. Pp-ANP1a has no significant identity to any known proteins, while Pp-ANP2a shows ∼30% identity to E. coli heat-labile enterotoxin (LT) subunit A and cholera toxin (CT) subunit A. Protein modeling indicates that Pp-ANP2a is structurally similar to CT/LT and likely acts as an ADP-ribosyltransferase. Despite the similarity, Pp-ANP shows several characteristics distinct from CT/LT toxins. Our results indicate that Pp-ANP is a new enterotoxin-like binary toxin with potent and specific activity to nematodes. The potency and specificity of Pp-ANP suggest applications in controlling parasitic nematodes and open an avenue for further research on its mechanism of action and role in bacterium-nematode interaction. IMPORTANCE This study reports the discovery of a new enterotoxin-like binary protein, Pp-ANP, from a Pseudomonas protegens strain. Pp-ANP shows strong nematicidal activity against Caenorhabditis elegans larvae and older-staged worms. It also shows strong activity on other free-living nematodes ( Pristionchus pacificus , Panagrellus redivivus , and Acrobeloides sp.). The two subunits, Pp-ANP1a and Pp-ANP2a, can be expressed separately and reconstituted to form the active complex. Pp-ANP shows some distinct characteristics compared with other toxins, including Escherichia coli enterotoxin and cholera toxin. The present study indicates that Pp-ANP is a novel binary toxin and that it has potential applications in controlling parasitic nematodes and in studying toxin-host interaction. Copyright © 2017 Wei et al.

Characterization of rhizosphere bacteria for control of phytopathogenic fungi of tomato.

PubMed

Pastor, Nicolás; Carlier, Evelin; Andrés, Javier; Rosas, Susana B; Rovera, Marisa

2012-03-01

Fluorescent Pseudomonas spp., isolated from rhizosphere soil of tomato and pepper plants, were evaluated in vitro as potential antagonists of fungal pathogens. Strains were characterized using the API 20NE biochemical system, and tested against the causal agents of stem canker and leaf blight (Alternaria alternata f. sp. lycopersici), southern blight (Sclerotium rolfsii Sacc.), and root rot (Fusarium solani). To this end, dual culture antagonism assays were carried out on 25% Tryptic Soy Agar, King B medium, and Potato Dextrose Agar to determine the effect of the strains on mycelial growth of the pathogens. The effect of two concentrations of FeCl(3) on antagonism against Alternaria alternata f. sp. lycopersici was also tested. In addition, strains were screened for ability to produce exoenzymes and siderophores. Finally, the selected Pseudomonas strain, PCI2, was evaluated for effect on tomato seedling development and as a potential candidate for controlling tomato damping-off caused by Sclerotium rolfsii Sacc., under growth chamber conditions. All strains significantly inhibited Alternaria alternata f. sp. lycopersici, particularly in 25% TSA medium. Antagonistic effect on Sclerotium rolfsii Sacc. and Fusarium solani was greater on King B medium. Protease was produced by 30% of the strains, but no strains produced cellulase or chitinase. Growth chamber studies resulted in significant increases in plant stand as well as in root dry weight. PCI2 was able to establish and survive in tomato plants rhizosphere after 40 days following planting of bacterized seeds. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterization and biotoxicity assessment of dissolved organic matter in RO concentrate from a municipal wastewater reclamation reverse osmosis system.

PubMed

Sun, Ying-Xue; Gao, Yue; Hu, Hong-Ying; Tang, Fang; Yang, Zhe

2014-12-01

Reverse osmosis (RO) concentrate from municipal wastewater reclamation reverse osmosis (mWRRO) system containing organic compounds may associate with toxic risk, and its discharge might pose an environmental risk. To identify a basis for the selection of feasible technology in treating RO concentrates, the characteristics and biotoxicity of different fractions of dissolved organic matter (DOM) in RO concentrates from an mWRRO system were investigated. The results indicated that the hydrophilic neutrals (HIN), hydrophobic acids (HOA) and hydrophobic bases (HOB) accounted for 96% of the dissolved organic carbon (DOC) of the total DOM in the RO concentrate. According to the SEC chromatograph detected at 254 nm wavelength of UV, the DOM with molecular weight (MW) 1-3 kDa accounted for the majority of the basic and neutral fractions. The fluorescence spectra of the excitation emission matrix (EEM) indicated that most aromatic proteins, humic/fulvic acid-like and soluble microbial by-product-like substances existed in the fractions HOA and hydrophobic neutrals (HON). The genotoxicity and anti-estrogenic activity of the RO concentrate were 1795.6 ± 57.2 μg 4-NQOL(-1) and 2.19 ± 0.05 mg TAM L(-1), respectively. The HIN, HOA, and HOB contributed to the genotoxicity of the RO concentrate, and the HIN was with the highest genotoxic level of 1007.9 ± 94.8 μg 4-NQOL(-1). The HOA, HON, and HIN lead to the total anti-estrogenic activity of the RO concentrate, and HOA occupied approximately 60% of the total, which was 1.3 ± 0.17 mg TAM L(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

Second generation sequencing of microRNA in Human Bone Cells treated with Parathyroid Hormone or Dexamethasone.

PubMed

Laxman, Navya; Rubin, Carl-Johan; Mallmin, Hans; Nilsson, Olle; Tellgren-Roth, Christian; Kindmark, Andreas

2016-03-01

We investigated the impact of treatment with parathyroid hormone (PTH) and dexamethasone (DEX) for 2 and 24h by RNA sequencing of miRNAs in primary human bone (HOB) cells. A total of 207 million reads were obtained, and normalized absolute expression retrieved for 373 most abundant miRNAs. In naïve control cells, 7 miRNAs were differentially expressed (FDR<0.05) between the two time points. Ten miRNAs exhibited differential expression (FDR <0.05) across two time points and treatments after adjusting for expression in controls and were selected for downstream analyses. Results show significant effects on miRNA expression when comparing PTH with DEX at 2h with even more pronounced effects at 24h. Interestingly, several miRNAs exhibiting differences in expression are predicted to target genes involved in bone metabolism e.g. miR-30c2, miR-203 and miR-205 targeting RUNX2, and miR-320 targeting β-catenin (CTNNB1) mRNA expression. CTNNB1and RUNX2 levels were decreased after DEX treatment and increased after PTH treatment. Our analysis also identified 2 putative novel miRNAs in PTH and DEX treated cells at 24h. RNA sequencing showed that PTH and DEX treatment affect miRNA expression in HOB cells and that regulated miRNAs in turn are correlated with expression levels of key genes involved in bone metabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

The New Antimicrobial Peptide SpHyastatin from the Mud Crab Scylla paramamosain with Multiple Antimicrobial Mechanisms and High Effect on Bacterial Infection

PubMed Central

Shan, Zhongguo; Zhu, Kexin; Peng, Hui; Chen, Bei; Liu, Jie; Chen, Fangyi; Ma, Xiaowan; Wang, Shuping; Qiao, Kun; Wang, Kejian

2016-01-01

SpHyastatin was first identified as a new cationic antimicrobial peptide in hemocytes of the mud crab Scylla paramamosain. Based on the amino acid sequences deduced, it was predicted that this peptide was composed of two different functional domains, a proline-rich domain (PRD) and a cysteine-rich domain (CRD). The recombinant product of SpHyastatin displayed potent antimicrobial activities against the human pathogen Staphylococcus aureus and the aquatic animal pathogens Aeromonas hydrophila and Pseudomonas fluorescens. Compared with the CRD of SpHyastatin, the PRD presented better antimicrobial and chitin binding activities, but both regions were essential for allowing SpHyastatin complete antimicrobial activity. The binding properties of SpHyastatin to different microbial surface molecules suggested that this might be an initial and crucial step for performing its antimicrobial activities. Evaluated using propidium iodide uptake assays and scanning electron microscopy images, the antimicrobial mechanism of SpHyastatin was found to be prone to disrupt cell membrane integrity. Interestingly, SpHyastatin exerted its role specifically on the surface of S. aureus and Pichia pastoris whereas it directly killed P. fluorescens through simultaneous targeting the membrane and the cytoplasm, indicating that SpHyastatin could use different antimicrobial mechanisms to kill different species of microbes. As expected, the recombinant SpHyastatin increased the survival rate of crabs challenged with Vibrio parahaemolyticus. In addition, SpHyastatin could modulate some V. parahaemolyticus-responsive genes in S. paramamosain. PMID:27493644

Gas phase bio-filter for the removal of triethylamine (TEA) from air: microbial diversity analysis with reference to design parameters.

PubMed

Gandu, Bharath; Sandhya, K; Gangagni Rao, A; Swamy, Y V

2013-07-01

Biotic (packed bio-filter; PBF) and abiotic (packed filter; PF) studies were carried out on two similar 2L gas phase filters for the removal of triethylamine (TEA) at inlet concentration in the range of 250-280 ppmV. Removal efficiency (RE) of PBF remained in the range of 90-99% during the stable period of operation (170 days) whereas RE of PF dropped gradually to 10% in a span of 90 days. Five different bacterial species viz; Aeromonas sp., Alcaligenes sp., Arthrobacter sp., Klebsiella sp., and Pseudomonas sp., were identified in PBF. It was observed that diethyl amine, ethylamine and nitrate were formed as metabolites during the degradation pathway. Empty bed residence time of 20s, mass loading rate of 202.26 g/m(3)/h, space velocity of 178.82 m(3)/m(3)/h and elimination capacity of 201.52 g/m(3)/h were found to be optimum design parameters for PBF to get RE in the range of 90-99%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Simultaneous biodegradation of bifenthrin and chlorpyrifos by Pseudomonas sp. CB2.

PubMed

Zhang, Qun; Li, Shuhuai; Ma, Chen; Wu, Nancun; Li, Chunli; Yang, Xinfeng

2018-05-04

The degradation of bifenthrin (BF) and chlorpyrifos (CP), either together or individually, by a bacterial strain (CB2) isolated from activated sludge was investigated. Strain CB2 was identified as belonging to genus Pseudomonas based on the morphological, physiological, and biochemical characteristics and a homological analysis of the 16S rDNA sequence. Strain CB2 has the potential to degrade BF and CP, either individually or in a mixture. The optimum conditions for mixture degradation were as follows: OD 600nm = 0.5; incubation temperature = 30°C; pH = 7.0; BF-CP mixture (10 mg L -1 of each). Under these optimal conditions, the degradation rate constants (and half-lives) were 0.4308 d -1 (1.61 d) and 0.3377 d -1 (2.05 d) for individual BF and CP samples, respectively, and 0.3463 d -1 (2.00 d) and 0.2931 d -1 (2.36 d) for the BF-CP mixture. Major metabolites of BF and CP were 2-methyl-3-biphenylyl methanol and 3,5,6-trichloro-2-pyridinol, respectively. No metabolite bioaccumulation was observed. The ability of CB2 to efficiently degrade BF and CP, particularly in a mixture, may be useful in bioremediation efforts.

Adsorption-synergic biodegradation of diesel oil in synthetic seawater by acclimated strains immobilized on multifunctional materials.

PubMed

Wang, Xin; Wang, Xuejiang; Liu, Mian; Bu, Yunjie; Zhang, Jing; Chen, Jie; Zhao, Jianfu

2015-03-15

Using enrichment culture technique, three isolates marked as ODB-1, ODB-2 and ODB-3, were selected from oil contaminated seawater. 16S rDNA gene sequencing indicated that ODB-1 affiliated with Pseudomonas sp. while ODB-2 and ODB-3 affiliated with Brevundimonas sp. Subsequently, the bacterial cells were immobilized on the surface of expanded graphite (EG), expanded perlite (EP) and bamboo charcoal (BC). Among the three isolates, ODB-1 showed a strong binding to the bio-carriers through extracellular polysaccharides, while ODB-2 and ODB-3 made the adhesion to bio-carrier through direct physical adsorption. The immobilized bacteria exhibited good salinity tolerance compared with the planktonic bacteria. Their total diesel oil removal rates were more than 85% after 6 days' incubation. Adsorption-biodegradation process played an important role in the oil-pollution remediation. EG-bacteria system was treated as a promising remediation method, which achieved nearly 100% removal of diesel oil. Thereinto, over 83% removal of diesel oil owed to biodegradation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fluorescent probe based subcellular distribution of Cu(II) ions in living electrotrophs isolated from Cu(II)-reduced biocathodes of microbial fuel cells.

PubMed

Tao, Ye; Xue, Hua; Huang, Liping; Zhou, Peng; Yang, Wei; Quan, Xie; Yuan, Jinxiu

2017-02-01

Based on the four indigenous electrotrophs (Stenotrophomonas maltophilia JY1, Citrobacter sp. JY3, Pseudomonas aeruginosa JY5 and Stenotrophomonas sp. JY6) isolated from well adapted Cu(II)-reduced biocathodes of microbial fuel cells (MFCs), a rhodamine based Cu(II) fluorescent probe was used to imaginably and quantitatively track subcellular Cu(II) ions in these electrotrophs. Cathodic electrons led to more Cu(II) ions (14.3-30.1%) in the intracellular sites at operation time of 2-3h with Cu(II) removal rates of 2.90-3.64mg/Lh whereas the absence of cathodic electrons prolonged the appearance of more Cu(II) ions (16.6-22.5%) to 5h with Cu(II) removal rates of 1.96-2.28mg/Lh. This study illustrates that cathodic electrons directed more Cu(II) ions for quicker entrance into the electrotrophic cytoplasm, and gives an alternative approach for developing imaging and functionally tracking Cu(II) ions in the electrotrophs of MFCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radiation pasteurization of mink feed: Effect of irradiated feed on reproductive performance, growth and fur quality of mink

NASA Astrophysics Data System (ADS)

Passey, C. A.; Roy, D.; Savoie, L.; Malo, R.; Wilson, J.

No significant differences were observed in the net birth rate of kits/female between the 7 breeding groups. However, there was reduced incidence (P = 0.05) of kit deaths among the females receiving irradiated feed, and larger kit size (P < 0.0001) at birth particularly for the litter size of 5-8 kits. The second generation minks born to parents receiving feed irradiated to a planned dose of 1 kGy weighed on average about 2.5 % more, and their fur was on average about 1 ± 0.26 cm longer (12 % more males making the top length grade). Moreover, there was no effect of irradiated feed on fur quality. Irradiation of mink feed with subsequent frozen storage of the meat component improved the microbiological quality by decreasing the incidence of Pseudomonas sp. and Salmonella sp. Radiation pasteurization of mink feed (frozen meat to 1 kGy, and dry feed to 2 kGy or more) should therefore help improve feed utilization, keep the animals healthier, and reproducing better without affecting fur quality.

Diversity of metabolic capacities among strains degrading polycyclic aromatic hydrocarbons

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

Bouchez, M.; Besnaienou, B.; Blanchet, D.

1995-12-31

Strains of Pseudomonas and Rhodococcus genera were isolated for their capacity to use, as a sole carbon and energy source, one of the following polycyclic aromatic hydrocarbons (PAHs): naphthalene (NAP), fluorene (FLU), phenanthrene (PHE), anthracene (ANT), fluoranthene (FLT), and pyrene (PYR). The range of PAHs supporting growth of these pure strains was usually restricted, but several other hydrocarbons were used by Rhodococcus sp. All strains could grow on simple organic acids. Maximal specific growth rates ({mu}{sub max}) of all strains on their PAH growth substrates were determined by respirometry. No clear relationships between {mu}{sub max} values and the molecular weightmore » or water solubility of PAHs were apparent, but Pseudomonas sp. exhibited the highest {mu}{sub max} values. Carbon balances for PAH biodegradation were established. Differences between strains were observed, but high mineralization rates and low production of soluble metabolites were obtained for all PAHs. Bacterial biomass represented 16% to 35% of the carbon consumed. Strain diversity was also apparent in the interactions observed in the degradation of a mixture of two PAHs by individual strains, which often involved inhibition of PAH substrate degradation, with or without cometabolization of the second PAH.« less

Pharmacokinetic Studies of Tobramycin and Gentamicin

PubMed Central

Simon, V. K.; Mösinger, E. U.; Malerczy, V.

1973-01-01

Broth dilution susceptibility tests of 100 isolates of Pseudomonas aeruginosa and 101 isolates of Staphylococcus aureus against tobramycin (formerly nebramycin factor 6) and gentamicin showed that tobramycin was more effective against P. aeruginosa and less effective against S. aureus. The minimal inhibitory concentration of tobramycin against the Pseudomonas sp. isolates that required 5 μg of gentamicin per ml for inhibition ranged from 0.63 to 0.31 μg/ml. Peak concentrations in the blood of 10 healthy adults after intramuscular injection of 80 and 40 mg of tobramycin averaged 3.7 ± 0.62 and 2.4 ± 0.27 μg/ml, and declined to 0.56 ± 0.05 and 0.26 ± 0.02 μg/ml, respectively, after 6 h. The urine recovery averaged 60%. The half-life was 1.6 h. During continuous intravenous infusion of tobramycin and gentamicin (infusion rate 6.6 mg per h), blood levels at steady state were 0.94 ± 0.10 and 1.04 ± 0.06 μg/ml, respectively. For both antibiotics, the calculated distribution volume ranged from 15 to 17 liters. The renal clearance to tobramycin averaged 76% and that of gentamicin averaged 85% of the total clearance, indicating that the drugs are primarily eliminated by the kidneys. The present results suggest that tobramycin may be more successful in the treatment of Pseudomonas infections than gentamicin at the same dosage (80 mg intramuscularly three to four times daily). PMID:4208289

Performance of a pilot-scale submerged membrane bioreactor (MBR) in treating bathing wastewater.

PubMed

Xia, Siqing; Guo, Jifeng; Wang, Rongchang

2008-10-01

Bathing wastewater was treated by a pilot-scale submerged membrane bioreactor (MBR) for more than 60 days. The results showed that the removal rates of main pollutants of wastewater such as COD(Cr), LAS, NH(4)(+)-N and total nitrogen (TN) were above 93%, 99%, 99%, and 90%, respectively. The results of denaturing gel gradient electrophoresis (DGGE) and fluorescent in situ hybridization (FISH) indicated that the bacteria were stable. The abundant nitrobacteria intercepted by the membrane led to the high removal rate of ammonia and TN. FISH and 16S rDNA gene sequence analysis revealed that some specific phylogenetic group of bacteria, the Pseudomonas sp. Ochrobactrum anthropi sp. and Enterobacter sp. probably played a major role in the development of the mature biofilms, which led to the severe irreversible membrane biofouling.

Bioactive metabolites from an endophytic Cryptosporiopsis sp. inhabiting Clidemia hirta.

PubMed

Zilla, Mahesh K; Qadri, Masroor; Pathania, Anup S; Strobel, Gary A; Nalli, Yedukondalu; Kumar, Sunil; Guru, Santosh K; Bhushan, Shashi; Singh, Sanjay K; Vishwakarma, Ram A; Riyaz-Ul-Hassan, Syed; Ali, Asif

2013-11-01

An endophytic Cryptosporiopsis sp. was isolated from Clidemia hirta and analyzed for its secondary metabolites that lead to the isolation of three bioactive molecules. The compounds were purified from the culture broth of the fungus and their structures were determined by spectroscopic methods as (R)-5-hydroxy-2-methylchroman-4-one (1), 1-(2,6-dihydroxyphenyl)pentan-1-one (2) and (Z)-1-(2-(2-butyryl-3-hydroxyphenoxy)-6-hydroxyphenyl)-3-hydroxybut-2-en-1-one (3). Compound 1 exhibited significant cytotoxic activity against the human leukemia cell line, HL-60 with an IC50 of 4 μg/ml. This compound induced G2 arrest of the HL-60 cell cycle significantly. In addition, out of these compounds, 2 and 3 were active against several bacterial pathogens. Compound 2 was active against Bacillus cereus, Escherichia coli and Staphylococcus aureus with IC50 values varying from 18 to 30 μg/ml, and compound 3 displayed activity against Pseudomonas fluorescens with an IC50 value of 6 μg/ml. Compounds 2 and 3 are novel whereas compound 1 was reported earlier but the stereochemistry of its C-2 methyl is established for the first time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Purification and Characterization of Allophanate Hydrolase (AtzF) from Pseudomonas sp. Strain ADP

PubMed Central

Shapir, Nir; Sadowsky, Michael J.; Wackett, Lawrence P.

2005-01-01

AtzF, allophanate hydrolase, is a recently discovered member of the amidase signature family that catalyzes the terminal reaction during metabolism of s-triazine ring compounds by bacteria. In the present study, the atzF gene from Pseudomonas sp. strain ADP was cloned and expressed as a His-tagged protein, and the protein was purified and characterized. AtzF had a deduced subunit molecular mass of 66,223, based on the gene sequence, and an estimated holoenzyme molecular mass of 260,000. The active protein did not contain detectable metals or organic cofactors. Purified AtzF hydrolyzed allophanate with a kcat/Km of 1.1 × 104 s−1 M−1, and 2 mol of ammonia was released per mol allophanate. The substrate range of AtzF was very narrow. Urea, biuret, hydroxyurea, methylcarbamate, and other structurally analogous compounds were not substrates for AtzF. Only malonamate, which strongly inhibited allophanate hydrolysis, was an alternative substrate, with a greatly reduced kcat/Km of 21 s−1 M−1. Data suggested that the AtzF catalytic cycle proceeds through a covalent substrate-enzyme intermediate. AtzF reacts with malonamate and hydroxylamine to generate malonohydroxamate, potentially derived from hydroxylamine capture of an enzyme-tethered acyl group. Three putative catalytically important residues, one lysine and two serines, were altered by site-directed mutagenesis, each with complete loss of enzyme activity. The identity of a putative serine nucleophile was probed using phenyl phosphorodiamidate that was shown to be a time-dependent inhibitor of AtzF. Inhibition was due to phosphoroamidation of Ser189 as shown by liquid chromatography/matrix-assisted laser desorption ionization mass spectrometry. The modified residue corresponds in sequence alignments to the nucleophilic serine previously identified in other members of the amidase signature family. Thus, AtzF affects the cleavage of three carbon-to-nitrogen bonds via a mechanism similar to that of enzymes catalyzing single-amide-bond cleavage reactions. AtzF orthologs appear to be widespread among bacteria. PMID:15901697

Purification and characterization of 9-hexadecenoic acid cis-trans isomerase from pseudomonas sp. strain E-3

PubMed

Okuyama; Ueno; Enari; Morita; Kusano

1998-01-01

A 9-hexadecenoic acid cis-trans isomerase (9-isomerase) that catalyzed the cis-to-trans isomerization of the double bond of free 9-cis-hexadecenoic acid [16:1(9c)] was purified to homogeneity from an extract of Pseudomonas sp. strain E-3 and characterized. Electrophoresis of the purified enzyme on both incompletely denaturing and denaturing polyacrylamide gels yielded a single band of a protein with a molecular mass of 80 kDa, suggesting that the isomerase is a monomeric protein of 80 kDa. The 9-isomerase, assayed with 16:1(9c) as a substrate, had a specific activity of 22.8 &mgr;mol h-1 (mg protein)-1 and a Km of 117.6 mM. The optimal pH and temperature for catalysis were approximately pH 7-8 and 30 degrees C, respectively. The 9-isomerase catalyzed the cis-to-trans conversion of a double bond at positions 9, 10, or 11, but not that of a double bond at position 6 or 7 of cis-mono-unsaturated fatty acids with carbon chain lengths of 14, 15, 16, and 17. Octadecenoic acids with a double bond at position 9 or 11 were not susceptible to isomerization. These results suggest that 9-isomerase has a strict specificity for both the position of the double bond and the chain length of the fatty acid. The enzyme catalyzed the cis-to-trans isomerization of fatty acids in a free form, and in the presence of a membrane fraction it was also able to isomerize 16:1(9c) esterified to phosphatidylethanolamine. The 9-isomerase was strongly inhibited by catecholic antioxidants such as alpha-tocopherol and nordihydroguaiaretic acid, but was not inhibited by 1, 10-phenanthroline or EDTA or under anoxic conditions. Based on these results, the possible mechanism of catalysis by this enzyme is discussed.

Classification of "Pseudomonas azotocolligans" Anderson 1955, 132, in the genus Sphingomonas as Sphingomonas trueperi sp. nov.

PubMed

Kämpfer, P; Denner, E B; Meyer, S; Moore, E R; Busse, H J

1997-04-01

"Pseudomonas azotocolligans" ATCC 12417T (T = type strain), which was described as a diazotrophic bacterium, was reinvestigated to clarify its taxonomic position. 16S ribosomal DNA sequence comparisons demonstrated that this strain clusters phylogenetically with species of the genus Sphingomonas and represents a new species. The results of investigations of the fatty acid patterns, polar lipid profiles, and quinone system supported this placement. The substrate utilization profile and biochemical characteristics displayed no obvious similarity to the characteristics of any previously described species of the genus Sphingomonas. The new name Sphingomonas trueperi is proposed on the basis of these results and previously published data for the G + C content of the genomic DNA and the polyamine pattern.

Degradation of 2-chloroallylalcohol by a Pseudomonas sp.

PubMed Central

van der Waarde, J J; Kok, R; Janssen, D B

1993-01-01

Three Pseudomonas strains capable of utilizing 2-chloroallylalcohol (2-chloropropenol) as the sole carbon source for growth were isolated from soil. The fastest growth was observed with strain JD2, with a generation time of 3.6 h. Degradation of 2-chloroallylalcohol was accompanied by complete dehalogenation. Chloroallylalcohols that did not support growth were dechlorinated by resting cells; the dechlorination level was highest if an alpha-chlorine substituent was present. Crude extracts of strain JD2 contained inducible alcohol dehydrogenase activity that oxidized mono- and dichloroallylalcohols but not trichloroallylalcohol. The enzyme used phenazine methosulfate as an artificial electron acceptor. Further oxidation yielded 2-chloroacrylic acid. The organism also produced hydrolytic dehalogenases converting 2-chloroacetic acid and 2-chloropropionic acid. PMID:8434917

Exploration of indigenous bacteria in an intensive aquaculture system of African catfish (Clarias sp.) in Banyuwangi, Indonesia

NASA Astrophysics Data System (ADS)

Prayogo; Rahardja, B. S.; Asshanti, A. N.; Dewi, N. N.; Santanumurti, M. B.

2018-04-01

Intensive African catfish culture in tarpaulin pond was popular in Banyuwangi, Indonesia since the government supported the fisheries sector. Unfortunately, the failure of African catfish culture still occurred since the waste from fish metabolite process and feed residue decreased the water quality. Bacteria in the water could be the solution to increase the success rate of aquaculture by improving the water quality. This study purpose was to obtained indigenous bacteria in intensive aquaculture system of African catfish to improve water quality. This study successfully isolated bacteria contained with amylase, protease and lipase characteristic. Isolated bacteria in this study were identified as Pseudomonas pseudomallei (97.81%), Bacillus subtilis (95.81%) and Pseudomonas stutzeri (61.21%).

Oil removal from petroleum sludge using bacterial culture with molasses substrate at temperature variation

NASA Astrophysics Data System (ADS)

Ni'matuzahroh, Puspitasari, Alvin Oktaviana; Pratiwi, Intan Ayu; Fatimah, Sumarsih, Sri; Surtiningsih, Tini; Salamun

2016-03-01

The study aims to reveal the potency of biosurfactant-producing bacterial culture with molasses as substrate growth in releasing oil from the petroleum sludge at temperature variations. Bacteria used consisted of (Acinetobacter sp. P2(1), Pseudomonas putida T1(8), Bacillus subtilis 3KP and Micrococcus sp. L II 61). The treatments were tested at 40°C, 50°C and 60 °C for 7 days of incubation. Synthetic surfactant (Tween 20) was used as a positive control and molasses as a negative control. Release of petroleum hydrocarbons from oil sludge was expressed in percentage of oil removal from oil sludge (%). Data were analyzed statistically using the Analysis of Variance (α = 0.05) and continued with Games-Howell test. The kinds of bacterial cultures, incubation temperature and combination of both affected the percentage of oil removal. The abilities of Bacillus subtilis 3KP and Micrococcus sp. LII 61cultures in oil removal from oil sludge at the temperature exposure of 60°C were higher than Tween 20. Both of bacterial cultures grown on molasses can be proposed as a replacement for synthetic surfactant to clean up the accumulation of oil sludge in a bottom of oil refinery tank.

BOOK REVIEW: ESTUARINE SCIENCE: A SYNTHETIC APPROACH TO RESEARCH AND PRACTICE

EPA Science Inventory

This book is the product of fifty leading estuarine scientists most of whom attended a workshop convened for the purpose of "put[ting] together the case for synthesis of estuarine data and to show the capabilities of synthetic methods of research" (p. 2). The editor, John E. Hob...

Composts containing fluorescent pseudomonads suppress fusarium root and stem rot development on greenhouse cucumber.

PubMed

Bradley, Geoffrey G; Punja, Zamir K

2010-11-01

Three composts (Ball, dairy, and greenhouse) were tested for the ability to suppress the development of Fusarium root and stem rot (caused by Fusarium oxysporum f. sp. radicis-cucumerinum) on greenhouse cucumber. Dairy and greenhouse composts significantly reduced disease severity (P = 0.05), while Ball compost had no effect. Assessment of total culturable microbes in the composts showed a positive relationship between disease suppressive ability and total population levels of pseudomonads. In vitro antagonism assays between compost-isolated bacterial strains and the pathogen showed that strains of Pseudomonas aeruginosa exhibited the greatest antagonism. In growth room trials, strains of P. aeruginosa and nonantagonistic Pseudomonas maculicola, plus 2 biocontrol strains of Pseudomonas fluorescens, were tested for their ability to reduce (i) survival of F. oxysporum, (ii) colonization of plants by the pathogen, and (iii) disease severity. Cucumber seedlings grown in compost receiving P. aeruginosa and P. fluorescens had reduced disease severity index scores after 8 weeks compared with control plants without bacteria. Internal stem colonization by F. oxysporum was significantly reduced by P. aeruginosa. The bacteria colonized plant roots at 1.9 × 10(6) ± 0.73 × 10(6) CFU·(g root tissue)-1 and survival was >107 CFU·(g compost)-1 after 6 weeks. The locus for 2,4-diacetylphloroglucinol production was detected by Southern blot analysis and confirmed by PCR. The production of the antibiotic 2,4-diacetylphloroglucinol in liquid culture by P. aeruginosa was confirmed by thin layer chromatography. These results demonstrate that composts containing antibiotic-producing P. aeruginosa have the potential to suppress diseases caused by Fusarium species.

Simply enhancing throughput of free-flow electrophoresis via organic-aqueous environment for purification of weak polarity solute of phenazine-1-carboxylic acid in fermentation of Pseudomonas sp. M18.

PubMed

Yang, Jing-Hua; Shao, Jing; Wang, Hou-Yu; Dong, Jing-Yu; Fan, Liu-Yin; Cao, Cheng-Xi; Xu, Yu-Quan

2012-09-01

Herein, a simple novel free-flow electrophoresis (FFE) method was developed via introduction of organic solvent into the electrolyte system, increasing the solute solubility and throughput of the sample. As a proof of concept, phenazine-1-carboxylic acid (PCA) from Pseudomonas sp. M18 was selected as a model solute for the demonstration on feasibility of novel FFE method on account of its faint solubility in aqueous circumstance. In the developed method, the organic solvent was added into not only the sample buffer to improve the solubility of the solute, but also the background buffer to construct a uniform aqueous-organic circumstance. These factors of organic solvent percentage and types as well as pH value of background buffer were investigated for the purification of PCA in the FFE device via CE. The experiments revealed that the percentage and the types of organic solvent exerted major influence on the purification of PCA. Under the optimized conditions (30 mM phosphate buffer in 60:40 (v/v) water-methanol at an apparent pH 7.0, 3.26 mL/min background flux, 10-min residence time of injected sample, and 400 V), PCA could be continuously purified from its impurities. The flux of sample injection was 10.05 μL/min, and the recovery was up to 93.7%. An 11.9-fold improvement of throughput was found with a carrier buffer containing 40% (v/v) methanol, compared with the pure aqueous phase. The developed procedure is of evident significance for the purification of weak polarity solute via FFE. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antibacterial potential of silver nanoparticles against isolated urinary tract infectious bacterial pathogens

NASA Astrophysics Data System (ADS)

Jacob Inbaneson, Samuel; Ravikumar, Sundaram; Manikandan, Nachiappan

2011-12-01

The silver nanoparticles were synthesized by chemical reduction method and the nanoparticles were characterized using ultraviolet-visible (UV-Vis) absorption spectroscopy and X-ray diffraction (XRD) studies. The synthesized silver nanoparticles were investigated to evaluate the antibacterial activity against urinary tract infectious (UTIs) bacterial pathogens. Thirty-two bacteria were isolated from mid urine samples of 25 male and 25 female patients from Thondi, Ramanathapuram District, Tamil Nadu, India and identified by conventional methods. Escherichia coli was predominant (47%) followed by Pseudomonas aeruginosa (22%), Klebsiella pneumoniae (19%), Enterobacter sp. (6%), Proteus morganii (3%) and Staphylococcus aureus (3%). The antibacterial activity of silver nanoparticles was evaluated by disc diffusion assay. P. aeruginosa showed maximum sensitivity (11 ± 0.58 mm) followed by Enterobacter sp. (8 ± 0.49 mm) at a concentration of 20 μg disc-1 and the sensitivity was highly comparable with the positive control kanamycin and tetracycline. K. pneumoniae, E. coli, P. morganii and S. aureus showed no sensitivity against all the tested concentrations of silver nanoparticles. The results provided evidence that, the silver nanoparticles might indeed be the potential sources to treat urinary tract infections caused by P. aeruginosa and Enterobacter sp.

Frequency and antimicrobial susceptibility of gram-negative bacteria isolated from 2 hospitals in Makkah, Saudi Arabia.

PubMed

Asghar, Atif H; Faidah, Hani S

2009-08-01

To estimate the prevalence and antibiotic susceptibility of the gram-negative bacteria isolated from 2 hospitals in Makkah. This study was undertaken in 2 main tertiary care hospitals namely; Al-Noor Specialist Hospital, and Hera Hospital in Makkah, Kingdom of Saudi Arabia from October 2005 to March 2006. A total of 1137 gram-negative bacteria were identified in non-duplicate clinical specimens obtained from 965 patients of various body sites infections. Demographic data, identity of microorganisms, and antimicrobial susceptibilities were obtained from medical and laboratory records. The most prevalent gram-negative bacteria were Escherichia coli (31.6%), and Pseudomonas aeruginosa (31.2%), followed by Acinetobacter baumannii (10.8%), Klebsiella pneumoniae (8.3%), Klebsiella sp. (6.2%), Haemophilus influenzae (3.7%), Proteus sp. (3.3%), and Enterobacter sp. (1.9%). Results demonstrated that gram-negative bacteria have a high rate of resistance to commonly used antibiotics. Furthermore, multi-drug resistance was also common in this study. Our data showed a high rate of resistance among gram-negative pathogens in comparison with other countries in the world. The implementation of monitoring programs is an important part of the prevention strategy against the development of antibiotic resistance in hospitals.

Electrokinetic-Enhanced Remediation of Phenanthrene-Contaminated Soil Combined with Sphingomonas sp. GY2B and Biosurfactant.

PubMed

Lin, Weijia; Guo, Chuling; Zhang, Hui; Liang, Xujun; Wei, Yanfu; Lu, Guining; Dang, Zhi

2016-04-01

Electrokinetic-microbial remediation (EMR) has emerged as a promising option for the removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils. The aim of this study was to enhance degradation of phenanthrene (Phe)-contaminated soils using EMR combined with biosurfactants. The electrokinetic (EK) remediation, combined with Phe-degrading Sphingomonas sp. GY2B, and biosurfactant obtained by fermentation of Pseudomonas sp. MZ01, degraded Phe in the soil with an efficiency of up to 65.1 % at the anode, 49.9 % at the cathode after 5 days of the treatment. The presence of biosurfactants, electricity, and a neutral electrolyte stimulated the growth of the degrading bacteria as shown by a rapid increase in microbial biomass with time. The electrical conductivity and pH changed little during the course of the treatment, which benefitted the growth of microorganisms and the remediation of Phe-contaminated soil. The EMR system with the addition of biosurfactant had the highest Phe removal, demonstrating the biosurfactant may enhance the bioavailability of Phe and the interaction with the microorganism. This study suggests that the EMR combined with biosurfactants can be used to enhance in situ bioremediation of PAH-contaminated soils.

Regulation of iron assimilation: nucleotide sequence analysis of an iron-regulated promoter from a fluorescent pseudomonad.

PubMed

O'Sullivan, D J; O'Gara, F

1991-08-01

An iron-regulated promoter was cloned on a 2.1 kb Bg/II fragment from Pseudomonas sp. strain M114 and fused to the lacZ reporter gene. Iron-regulated lacZ expression from the resulting construct (pSP1) in strain M114 was mediated via the Fur-like repressor which also regulates siderophore production in this strain. A 390 bp StuI-PstI internal fragment contained the necessary information for iron-regulated promoter expression. This fragment was sequenced and the initiation point for transcription was determined by primer extension analysis. The region directly upstream of the transcription start point contained no significant homology to known promoter consensus sequences. However the -16 to -25 bp region contained homology to four other iron-regulated pseudomonad promoters. Deletion of bases downstream from the transcriptional start did not affect the iron-regulated expression of the promoter. The -37 and -43 bp regions exhibited some homology to the 19 bp Escherichia coli Fur-binding consensus sequence. When expressed in E. coli (via a cloned transacting factor from strain M114) lacZ expression from pSP1 was found to be regulated by iron. A region of greater than 77 bases but less than 131 upstream from the transcriptional start was found to be necessary for promoter activity, further suggesting that a transcriptional activator may be required for expression.

The crystal structures of native hydroquinone 1,2-dioxygenase from Sphingomonas sp. TTNP3 and of substrate and inhibitor complexes.

PubMed

Ferraroni, Marta; Da Vela, Stefano; Kolvenbach, Boris A; Corvini, Philippe F X; Scozzafava, Andrea

2017-05-01

The crystal structure of hydroquinone 1,2-dioxygenase, a Fe(II) ring cleaving dioxygenase from Sphingomonas sp. strain TTNP3, which oxidizes a wide range of hydroquinones to the corresponding 4-hydroxymuconic semialdehydes, has been solved by Molecular Replacement, using the coordinates of PnpCD from Pseudomonas sp. strain WBC-3. The enzyme is a heterotetramer, constituted of two subunits α and two β of 19 and 38kDa, respectively. Both the two subunits fold as a cupin, but that of the small α subunit lacks a competent metal binding pocket. Two tetramers are present in the asymmetric unit. Each of the four β subunits in the asymmetric unit binds one Fe(II) ion. The iron ion in each β subunit is coordinated to three protein residues, His258, Glu264, and His305 and a water molecule. The crystal structures of the complexes with the substrate methylhydroquinone, obtained under anaerobic conditions, and with the inhibitors 4-hydroxybenzoate and 4-nitrophenol were also solved. The structures of the native enzyme and of the complexes present significant differences in the active site region compared to PnpCD, the other hydroquinone 1,2-dioxygenase of known structure, and in particular they show a different coordination at the metal center. Copyright © 2017 Elsevier B.V. All rights reserved.

Metals bioleaching from electronic waste by Chromobacterium violaceum and Pseudomonads sp.

PubMed

Pradhan, Jatindra Kumar; Kumar, Sudhir

2012-11-01

These days, electronic waste needs to be taken into consideration due to its materials content, but due to the heterogeneity of the metals present, reprocessing of electronic waste is quite limited. The bioleaching of metals from electronic waste was investigated by using cyanogenic bacterial strains (Chromobacterium violaceum, Pseudomonas aeruginosa and Pseudomonas fluorescens). A two-step bioleaching process was followed under cyanide-forming conditions for maximum metals mobilization. Both single and mixed cultures of cyanogenic bacteria were able to mobilize metals from electronic waste with different efficiencies. In all the flasks in which high metal mobilizations were observed, the consequent biomass productions were also high. Pseudomonas aeruginosa was applied in the bioleaching process for the first time and this achieved its bioleaching ability of mobilization of metals from electronic waste. Chromobacterium violaceum as a single culture and a mixture of C. violaceum and P. aeruginosa exhibited maximum metal mobilization. Chromobacterium violaceum was capable of leaching more than 79, 69, 46, 9 and 7% of Cu, Au, Zn, Fe and Ag, respectively at an electronic waste concentration of 1% w/v. Moreover, the mixture of C. violaceum and P. aeruginosa exhibited metals leaching of more than 83, 73, 49, 13 and 8% of total Cu, Au, Zn, Fe, and Ag, respectively. Precious metals were mobilized through bioleaching which might be considered as an industrial application for recycling of electronic waste in the near future.

Development and characterization of titanium-containing hydroxyapatite for medical applications.

PubMed

Huang, J; Best, S M; Bonfield, W; Buckland, Tom

2010-01-01

Hydroxyapatite containing levels of titanium (TiHA) of up to 1.6 wt.% has been produced via a chemical co-precipitation route. The distribution of Ti was seen by transmission electron microscopy/energy-dispersive X-ray analysis to be uniform throughout as-prepared nanosized TiHA particles (20 nm x 100 nm). The incorporation of Ti into the HA structure was found to influence the ceramic microstructure on sintering and the grain size was found to decrease from 0.89 microm with HA to 0.63 microm with 0.8 wt.% TiHA (0.8 TiHA) and 0.45 microm with 1.6 wt.% TiHA (1.6 TiHA). Rietveld refinement analysis showed that there was a proportional increase in both the a and c axis with incorporation of Ti into the HA lattice structure, leading to an increase in the cell volume with the addition of Ti. Fourier transform-Raman analysis showed a slight increase in the ratio of O-H/P-O peaks on TiHA, in comparison with HA. A bone-like apatite layer was formed on the surface of TiHA after immersion in simulated body fluid for 3 days, which demonstrated the high in vitro bioactivity of TiHA. In vitro culture with primary human osteoblast (HOB) cells revealed that TiHA was able to support the growth and proliferation of HOB cells in vitro, with a significantly higher cell activity being observed on 0.8 TiHA after 7 days of culture in comparison with that on HA. Well-organized actin cytoskeletal protein was developed after 1 day of culture, and an increase in cell filopodia (attachment) was observed on TiHA sample surfaces. The results indicate that TiHA has great potential for biomedical applications.

D-Amino Acids Enhance the Activity of Antimicrobials against Biofilms of Clinical Wound Isolates of Staphylococcus aureus and Pseudomonas aeruginosa

DTIC Science & Technology

2014-05-19

and P. aeruginosa biofilms. Screening of dispersive activity of individual D-amino acids, D-methionine (D-Met), D- phenylalanine (D-Phe), and D...Microb. Ecol. http://dx.doi.org/10.1007/s00248 -013-0297-x. 16. Roche ED, Renick PJ, Tetens SP, Ramsay SJ, Daniels EQ, Carson DL . 2012. Increasing the

Homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerant Pseudomonas sp. AMS8

PubMed Central

Garba, Lawal; Mohamad Yussoff, Mohamad Ariff; Abd Halim, Khairul Bariyyah; Ishak, Siti Nor Hasmah; Mohamad Ali, Mohd Shukuri; Oslan, Siti Nurbaya

2018-01-01

Membrane-bound fatty acid desaturases perform oxygenated desaturation reactions to insert double bonds within fatty acyl chains in regioselective and stereoselective manners. The Δ9-fatty acid desaturase strictly creates the first double bond between C9 and 10 positions of most saturated substrates. As the three-dimensional structures of the bacterial membrane fatty acid desaturases are not available, relevant information about the enzymes are derived from their amino acid sequences, site-directed mutagenesis and domain swapping in similar membrane-bound desaturases. The cold-tolerant Pseudomonas sp. AMS8 was found to produce high amount of monounsaturated fatty acids at low temperature. Subsequently, an active Δ9-fatty acid desaturase was isolated and functionally expressed in Escherichia coli. In this paper we report homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerant Pseudomonas sp. AMS8 for the first time to the best of our knowledge. Three dimensional structure of the enzyme was built using MODELLER version 9.18 using a suitable template. The protein model contained the three conserved-histidine residues typical for all membrane-bound desaturase catalytic activity. The structure was subjected to energy minimization and checked for correctness using Ramachandran plots and ERRAT, which showed a good quality model of 91.6 and 65.0%, respectively. The protein model was used to preform MD simulation and docking of palmitic acid using CHARMM36 force field in GROMACS Version 5 and Autodock tool Version 4.2, respectively. The docking simulation with the lowest binding energy, −6.8 kcal/mol had a number of residues in close contact with the docked palmitic acid namely, Ile26, Tyr95, Val179, Gly180, Pro64, Glu203, His34, His206, His71, Arg182, Thr85, Lys98 and His177. Interestingly, among the binding residues are His34, His71 and His206 from the first, second, and third conserved histidine motif, respectively, which constitute the active site of the enzyme. The results obtained are in compliance with the in vivo activity of the Δ9-fatty acid desaturase on the membrane phospholipids. PMID:29576935

Effect of trace metals and electron shuttle on simultaneous reduction of reactive black-5 azo dye and hexavalent chromium in liquid medium by Pseudomonas sp.

PubMed

Mahmood, Shahid; Khalid, Azeem; Arshad, Muhammad; Ahmad, Riaz

2015-11-01

This study demonstrates the role of electron shuttles and trace metals in the biotransformation of azo dye reactive black-5 and hexavalent chromium (CrVI) that are released simultaneously in tannery effluent. Previously isolated bacterial strain Pseudomonas putida KI was used for the simultaneous reduction of the dye (100 mg L(-1)) and CrVI (2 mg L(-1)) in a mineral salts medium (MSM). Among various trace metals, only Cu(II) had a stimulating effect on the bacterial-mediated reduction process. Application of electron shuttles such as hydroquinone and uric acid at a low concentration (1mM) had a positive effect on the reduction process and caused simultaneous reduction of 100% dye and 97% CrVI in 12-18 h. Mannitol, EDTA and sodium benzoate at all concentrations (ranging from 1 to 9 mM) showed an inhibitory effect on the reduction of reactive black-5 and CrVI. An inverse linear relationship between the velocity of reaction (V) and the concentration [S] of electron shuttles was observed. The results imply that both types and concentration of an electron shuttle and trace metals can affect the simultaneous reduction of reactive black-5 and CrVI. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimization of the liquid biofertilizer production in batch fermentation with by-product from MSG

NASA Astrophysics Data System (ADS)

Namfon, Panjanapongchai; Ratchanok, Sahaworarak; Chalida, Daengbussade

2017-03-01

The long term use of chemical fertilizers destroyed the friability of soil which obviously decreased quantity and quality of crops and especially affect microorganisms living in soils. The bio-fertilizer with microbial consortium is an environmental friendly alternative to solve this bottleneck due to harboring soil microorganisms such as Bacillus sp., Micrococcus sp., Pseudomonas sp., Staphylococcus sp. and Deinococcus sp. produced with natural by-product or waste from industries that is alternative and sustainable such as nutrient-rich (by-product) from Mono Sodium Glutamate (MSG) for producing liquid biofertilizer by batch fermentation. In this work, the concentration of reducing sugar from substrate as main carbon source was evaluated in shake flask with mixed cultures. The optimal conditions were studied comparing with two levels of reducing sugar concentration (10, 20 g/L) and inoculums concentration (10, 20 %v/v) with using (2×2) full factorial design. The results indicated that the by-product from monosodium glutamate is feasible for fermentation and inoculums concentration is mainly influenced the batch fermentation process. Moreover, the combined 20 g/L and 10%v/v were considerably concluded as an optimal condition, of which the concentration of vegetative cells and spores attained at 8.29×109 CFU/mL and 1.97×105 CFU/mL, respectively. Their spores cell yields from reducing sugar (Yx/s) were obtained at 1.22×106 and 3.34×105 CFU/g were markedly different. In conclusion, the liquid Biofertilizer was produced satisfactorily at 20 g/L reducing sugar and 10% v/v inoculums in shake flask culture. Moreover, these results suggested that the by-product from monosodium glutamate is feasible for low-cost substrate in economical scale and environmental-friendly.

Exposure of Cucurbita pepo to DDE-contamination alters the endophytic community: A cultivation dependent vs a cultivation independent approach.

PubMed

Eevers, N; Hawthorne, J R; White, J C; Vangronsveld, J; Weyens, N

2016-02-01

2,2-bis(p-chlorophenyl)-1,1-dichloro-ethylene (DDE) is the most abundant and persistent degradation product of the pesticide 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and is encountered in contaminated soils worldwide. Both DDE and DDT are classified as Persistent Organic Pollutants (POPs) due to their high hydrophobicity and potential for bioaccumulation and biomagnification in the food chain. Zucchini (Cucurbita pepo ssp. pepo) has been shown to accumulate high concentrations of DDE and other POPs and has been proposed as a phytoremediation tool for contaminated soils. The endophytic bacteria associated with this plant may play an important role in the remedial process. Therefore, this research focuses on changes in endophytic bacterial communities caused by the exposure of C. pepo to DDE. The total bacterial community was investigated using cultivation-independent 454 pyrosequencing, while the cultivable community was identified using cultivation-dependent isolation procedures. For both procedures, increasing numbers of endophytic bacteria, as well as higher diversities of genera were observed when plants were exposed to DDE. Several bacterial genera such as Stenotrophomonas sp. and Sphingomonas sp. showed higher abundance when DDE was present, while, for example Pseudomonas sp. showed a significantly lower abundance in the presence of DDE. These findings suggest tolerance of different bacterial strains to DDE, which might be incorporated in further investigations to optimize phytoremediation with the possible use of DDE-degrading endophytes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Brachybacterium sp. CH-KOV3 isolated from an oil-polluted environment-a new producer of levan.

PubMed

Djurić, Aleksandra; Gojgić-Cvijović, Gordana; Jakovljević, Dragica; Kekez, Branka; Kojić, Jovana Stefanović; Mattinen, Maija-Liisa; Harju, Inka Elina; Vrvić, Miroslav M; Beškoski, Vladimir P

2017-11-01

Various microorganisms isolated from polluted environments, such as Pseudomonas sp. and Micrococcus sp. can synthesize exopolysaccharides (EPSs) which are natural, non-toxic and biodegradable polymers. EPSs play a key role in protection of microbial cells under various external influences. For humans, these substances have potential use in many industries. EPSs can be applied as a flavor or a fragrance carrier, an emulsifier, a stabilizer, a prebiotic, an antioxidant or an antitumor agent. In this study, we characterized an environmental microorganism that produces EPS, optimized EPS production by this strain and characterized the EPS produced. Isolate CH-KOV3 was identified as Brachybacterium paraconglomeratum. The sucrose level in the growth medium greatly influenced EPS production, and the highest yield was when the microorganism was incubated in media with 500g/L of sucrose. The optimal temperature and pH were 28°C and 7.0, respectively. The nuclear magnetic resonance (NMR) results and GC-MS analysis confirmed that the residues were d-fructofuranosyl residues with β-configuration, where fructose units are linked by β-2,6-glycosidic bonds, with β-2,1-linked branches. All these data indicate that the investigated EPS is a levan-type polysaccharide. Thus, it was concluded that Brachybacterium sp. CH-KOV3 could constitute a new source for production of the bioactive polysaccharide, levan. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of a tryptophan 2-monooxygenase gene from Puccinia graminis f. sp. tritici involved in auxin biosynthesis and rust pathogenicity.

PubMed

Yin, Chuntao; Park, Jeong-Jin; Gang, David R; Hulbert, Scot H

2014-03-01

The plant hormone indole-3-acetic acid (IAA) is best known as a regulator of plant growth and development but its production can also affect plant-microbe interactions. Microorganisms, including numerous plant-associated bacteria and several fungi, are also capable of producing IAA. The stem rust fungus Puccinia graminis f. sp. tritici induced wheat plants to accumulate auxin in infected leaf tissue. A gene (Pgt-IaaM) encoding a putative tryptophan 2-monooxygenase, which makes the auxin precursor indole-3-acetamide (IAM), was identified in the P. graminis f. sp. tritici genome and found to be expressed in haustoria cells in infected plant tissue. Transient silencing of the gene in infected wheat plants indicated that it was required for full pathogenicity. Expression of Pgt-IaaM in Arabidopsis caused a typical auxin expression phenotype and promoted susceptibility to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000.

Investigating the compatibility of the biocontrol agent Clonostachys rosea IK726 with prodigiosin-producing Serratia rubidaea S55 and phenazine-producing Pseudomonas chlororaphis ToZa7.

PubMed

Kamou, Nathalie N; Dubey, Mukesh; Tzelepis, Georgios; Menexes, Georgios; Papadakis, Emmanouil N; Karlsson, Magnus; Lagopodi, Anastasia L; Jensen, Dan Funck

2016-05-01

This study was carried out to assess the compatibility of the biocontrol fungus Clonostachys rosea IK726 with the phenazine-producing Pseudomonas chlororaphis ToZa7 or with the prodigiosin-producing Serratia rubidaea S55 against Fusarium oxysporum f. sp. radicis-lycopersici. The pathogen was inhibited by both strains in vitro, whereas C. rosea displayed high tolerance to S. rubidaea but not to P. chlororaphis. We hypothesized that this could be attributed to the ATP-binding cassette (ABC) proteins. The results of the reverse transcription quantitative PCR showed an induction of seven genes (abcB1, abcB20, abcB26, abcC12, abcC12, abcG8 and abcG25) from subfamilies B, C and G. In planta experiments showed a significant reduction in foot and root rot on tomato plants inoculated with C. rosea and P. chlororaphis. This study demonstrates the potential for combining different biocontrol agents and suggests an involvement of ABC transporters in secondary metabolite tolerance in C. rosea.

Effect of toluene concentration and hydrogen peroxide on Pseudomonas plecoglossicida cometabolizing mixture of cis-DCE and TCE in soil slurry.

PubMed

Li, Junhui; Lu, Qihong; de Toledo, Renata Alves; Lu, Ying; Shim, Hojae

2015-12-01

An indigenous Pseudomonas sp., isolated from the regional contaminated soil and identified as P. plecoglossicida, was evaluated for its aerobic cometabolic removal of cis-1,2-dichloroethylene (cis-DCE) and trichloroethylene (TCE) using toluene as growth substrate in a laboratory-scale soil slurry. The aerobic simultaneous bioremoval of the cis-DCE/TCE/toluene mixture was studied under different conditions. Results showed that an increase in toluene concentration level from 300 to 900 mg/kg prolonged the lag phase for the bacterial growth, while the bioremoval extent for cis-DCE, TCE, and toluene declined as the initial toluene concentration increased. In addition, the cometabolic bioremoval of cis-DCE and TCE was inhibited by the presence of hydrogen peroxide as the additional oxygen source, while the bioremoval of toluene (900 mg/kg) was enhanced after 9 days of incubation. The subsequent addition of toluene did not improve the cometabolic bioremoval of cis-DCE and TCE. The obtained results would help to enhance the applicability of bioremediation technology to the mixed waste contaminated sites.

Microorganisms and heavy metals associated with atmospheric deposition in a congested urban environment of a developing country: Sri Lanka.

PubMed

Weerasundara, Lakshika; Amarasekara, R W K; Magana-Arachchi, D N; Ziyath, Abdul M; Karunaratne, D G G P; Goonetilleke, Ashantha; Vithanage, Meththika

2017-04-15

The presence of bacteria and heavy metals in atmospheric deposition were investigated in Kandy, Sri Lanka, which is a typical city in the developing world with significant traffic congestion. Atmospheric deposition samples were analyzed for Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb which are heavy metals common to urban environments. Al and Fe were found in high concentrations due to the presence of natural sources, but may also be re-suspended by vehicular traffic. Relatively high concentrations of toxic metals such as Cr and Pb in dissolved form were also found. High Zn loads can be attributed to vehicular emissions and the wide use of Zn coated roofing materials. The metal loads in wet deposition showed higher concentrations compared to dry deposition. The metal concentrations among the different sampling sites significantly differ from each other depending on the traffic conditions. Industrial activities are not significant in Kandy City. Consequently, the traffic exerts high influence on heavy metal loadings. As part of the bacterial investigations, nine species of culturable bacteria, namely; Sphingomonas sp., Pseudomonas aeruginosa, Pseudomonas monteilii, Klebsiella pneumonia, Ochrobactrum intermedium, Leclercia adecarboxylata, Exiguobacterium sp., Bacillus pumilus and Kocuria kristinae, which are opportunistic pathogens, were identified. This is the first time Pseudomonas monteilii and Ochrobactrum intermedium has been reported from a country in Asia. The culturable fraction constituted ~0.01 to 10%. Pigmented bacteria and endospore forming bacteria were copious in the atmospheric depositions due to their capability to withstand harsh environmental conditions. The presence of pathogenic bacteria and heavy metals creates potential human and ecosystem health risk. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative study of wastewater treatment and nutrient recycle via activated sludge, microalgae and combination systems.

PubMed

Wang, Liang; Liu, Jinli; Zhao, Quanyu; Wei, Wei; Sun, Yuhan

2016-07-01

Algal-bacterial synergistic cultivation could be an optional wastewater treatment technology in temperate areas. In this study, a locally screened vigorous Chlorella strain was characterized and then it was used in a comparative study of wastewater treatment and nutrient recycle assessment via activated sludge (AS), microalgae and their combination systems. Chlorella sp. cultured with AS in light showed the best performance, in which case the removal efficiencies of COD, NH3-N and TP were 87.3%, 99.2% and 83.9%, respectively, within a short period of 1day. Algal-bacterial combination in light had the best settleability. Chlorella sp. contained biomass, could be processed to feed, fertilizer or fuel due to the improved quality (higher C/H/N) compared with sludge. PCR-DGGE analysis shows that two types of rhizobacteria, namely, Pseudomonas putida and Flavobacterium hauense were enriched in sludge when cultured with algae in light, serving as the basics for artificial consortium construction for improved wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Airsacculitis in fourteen juvenile southern Bornean orangutans (Pongo pygmaeus wurmbii).

PubMed

Lawson, Becki; Garriga, Rosa; Galdikas, Biruté M F

2006-06-01

Airsacculitis is a clinical condition which has been reported in a range of primates species, including orangutans. This report describes the occurence and management of airsacculitis in fourteen juvenile Southern Bornean orangutans (Pongo pygmaeus wurmbii) that presented beween January 1st 1999 and January 31st 2001 at the Orangutan Care Center and Quarantine (OCC&Q), Kalimantan Tengah, Indonesia (S 2 degrees 43' 49.2"; E 111 degrees 38' 54.2"). Details of the signalment, clinical history, presenting clinical signs, clinicopathological findings and bacterial isolates in each case were reviewed. Cough, halitosis and nasal discharge were the most frequently observed clinical signs. A range of Gram-negative bacteria were isolated from infected air sacs, including Pseudomonas sp., Enterobacter sp. and Klebsiella pneumoniae. A simple drainage and lavage technique was used in cases where surgical intervention was indicated, in combination with local and systemic antibiotic therapy. The importance of early diagnosis, prompt management and antibiotic selection, based on bacterial culture and sensitivity profiles, is outlined.

Functional Characterization of a 28-Kilobase Catabolic Island from Pseudomonas sp. Strain M1 Involved in Biotransformation of β-Myrcene and Related Plant-Derived Volatiles

PubMed Central

Soares-Castro, Pedro; Montenegro-Silva, Pedro; Heipieper, Hermann J.

2017-01-01

ABSTRACT Pseudomonas sp. strain M1 is able to mineralize highly hydrophobic and recalcitrant compounds, such as benzene, phenol, and their methylated/halogenated derivatives, as well as the backbone of several monoterpenes. The ability to use such a spectrum of compounds as the sole carbon source is, most probably, associated with a genetic background evolved under different environmental constraints. The outstanding performance of strain M1 regarding β-myrcene catabolism was elucidated in this work, with a focus on the biocatalytical potential of the β-myrcene-associated core code, comprised in a 28-kb genomic island (GI), predicted to be organized in 8 transcriptional units. Functional characterization of this locus with promoter probes and analytical approaches validated the genetic organization predicted in silico and associated the β-myrcene-induced promoter activity to the production of β-myrcene derivatives. Notably, by using a whole-genome mutagenesis strategy, different genotypes of the 28-kb GI were generated, resulting in the identification of a novel putative β-myrcene hydroxylase, responsible for the initial oxidation of β-myrcene into myrcen-8-ol, and a sensor-like regulatory protein, whose inactivation abolished the myr+ trait of M1 cells. Moreover, it was demonstrated that the range of monoterpene substrates of the M1 enzymatic repertoire, besides β-myrcene, also includes other acyclic (e.g., β-linalool) and cyclic [e.g., R-(+)-limonene and (−)-β-pinene] molecules. Our findings are the cornerstone for following metabolic engineering approaches and hint at a major role of the 28-kb GI in the biotransformation of a broad monoterpene backbone spectrum for its future biotechnological applications. IMPORTANCE Information regarding microbial systems able to biotransform monoterpenes, especially β-myrcene, is limited and focused mainly on nonsystematic metabolite identification. Complete and detailed knowledge at the genetic, protein, metabolite, and regulatory levels is essential in order to set a model organism or a catabolic system as a biotechnology tool. Moreover, molecular characterization of reported systems is scarce, almost nonexistent, limiting advances in the development of optimized cell factories with strategies based on the new generation of metabolic engineering platforms. This study provides new insights into the intricate molecular functionalities associated with β-myrcene catabolism in Pseudomonas, envisaging the production of a molecular knowledge base about the underlying catalytic and regulatory mechanisms of plant-derived volatile catabolic pathways. PMID:28213543

The pathway to intelligent implants: osteoblast response to nano silicon-doped hydroxyapatite patterning

PubMed Central

Munir, G.; Koller, G.; Di Silvio, L.; Edirisinghe, M. J.; Bonfield, W.; Huang, J.

2011-01-01

Bioactive hydroxyapatite (HA) with addition of silicon (Si) in the crystal structure (silicon-doped hydroxyapatite (SiHA)) has become a highly attractive alternative to conventional HA in bone replacement owing to the significant improvement in the in vivo bioactivity and osteoconductivity. Nanometre-scaled SiHA (nanoSiHA), which closely resembles the size of bone mineral, has been synthesized in this study. Thus, the silicon addition provides an extra chemical cue to stimulate and enhance bone formation for new generation coatings, and the next stage in metallic implantation design is to further improve cellular adhesion and proliferation by control of cell alignment. Topography has been found to provide a powerful set of signals for cells and form contact guidance. Using the recently developed novel technique of template-assisted electrohydrodynamic atomization (TAEA), patterns of pillars and tracks of various dimensions of nanoSiHA were achieved. Modifying the parameters of TAEA, the resolution of pattern structures was controlled, enabling the topography of a substrate to be modified accordingly. Spray time, flow rate and distance between the needle and substrate were varied to improve the pattern formation of pillars and tracks. The 15 min deposition time provided the most consistent patterned topography with a distance of 50 mm and flow rate of 4 µl min−1. A titanium substrate was patterned with pillars and tracks of varying widths, line lengths and distances under the optimized TAEA processing condition. A fast bone-like apatite formation rate was found on nanoSiHA after immersion in simulated body fluid, thus demonstrating its high in vitro bioactivity. Primary human osteoblast (HOB) cells responded to SiHA patterns by stretching of the filopodia between track and pillar, attaching to the apex of the pillar pattern and stretching between two. HOB cells responded to the track pattern by elongating along and between the track, and the length of HOB cells was proportional to the gaps between track patterns, but this relationship was not observed on the pillar patterns. The study has therefore provided an insight for future design of next generation implant surfaces to control and guide cellular responses, while TAEA patterning provides a controllable technique to provide topography to medical implants. PMID:21208969

Biochemical basis of mercury remediation and bioaccumulation by Enterobacter sp. EMB21.

PubMed

Sinha, Arvind; Kumar, Sumit; Khare, Sunil Kumar

2013-01-01

The aims of this study were to isolate metal bioaccumulating bacterial strains and to study their applications in removal of environmental problematic heavy metals like mercury. Five bacterial strains belonging to genera Enterobacter, Bacillus, and Pseudomonas were isolated from oil-spilled soil. Among these, one of the strains Enterobacter sp. EMB21 showed mercury bioaccumulation inside the cells simultaneous to its bioremediation. The bioaccumulation of remediated mercury was confirmed by transmission electron microscopy and energy dispersive X-ray. The mercury-resistant loci in the Enterobacter sp. EMB21 cells were plasmid-mediated as confirmed by transformation of mercury-sensitive Escherichia coli DH5α by Enterobacter sp. EMB21 plasmid. Effect of different culture parameters viz-a-viz inoculum size, pH, carbon, and nitrogen source revealed that alkaline pH and presence of dextrose and yeast extract favored better remediation. The results indicated the usefulness of Enterobacter sp. EMB21 for the effective remediation of mercury in bioaccumulated form. The Enterobacter sp. EMB21 seems promising for heavy metal remediation wherein the remediated metal can be trapped inside the cells. The process can further be developed for the synthesis of valuable high-end functional alloy, nanoparticles, or metal conjugates from the metal being remediated.

Isolation and Characterization of Bacteria from the Gut of Bombyx mori that Degrade Cellulose, Xylan, Pectin and Starch and Their Impact on Digestion

PubMed Central

Anand, A. Alwin Prem; Vennison, S. John; Sankar, S. Gowri; Prabhu, D. Immanual Gilwax; Vasan, P. Thirumalai; Raghuraman, T.; Geoffrey, C. Jerome; Vendan, S. Ezhil

2010-01-01

Bombyx mori L. (Lepidoptera: Bombycidae) have been domesticated and widely used for silk production. It feeds on mulberry leaves. Mulberry leaves are mainly composed of pectin, xylan, cellulose and starch. Some of the digestive enzymes that degrade these carbohydrates might be produced by gut bacteria. Eleven isolates were obtained from the digestive tract of B. mori, including the Gram positive Bacillus circulans and Gram negative Proteus vulgaris, Klebsiella pneumoniae, Escherichia coli, Citrobacter freundii, Serratia liquefaciens, Enterobacter sp., Pseudomonas fluorescens, P. aeruginosa, Aeromonas sp., and Erwinia sp.. Three of these isolates, P. vulgaris, K. pneumoniae, C. freundii, were cellulolytic and xylanolytic, P. fluorescens and Erwinia sp., were pectinolytic and K. pneumoniae degraded starch. Aeromonas sp. was able to utilize the CMcellulose and xylan. S. liquefaciens was able to utilize three polysaccharides including CMcellulose, xylan and pectin. B. circulans was able to utilize all four polysaccharides with different efficacy. The gut of B. mori has an alkaline pH and all of the isolated bacterial strains were found to grow and degrade polysaccharides at alkaline pH. The number of cellulolytic bacteria increases with each instar. PMID:20874394

Isolation and characterization of bacteria from the gut of Bombyx mori that degrade cellulose, xylan, pectin and starch and their impact on digestion.

PubMed

Anand, A Alwin Prem; Vennison, S John; Sankar, S Gowri; Prabhu, D Immanual Gilwax; Vasan, P Thirumalai; Raghuraman, T; Geoffrey, C Jerome; Vendan, S Ezhil

2010-01-01

Bombyx mori L. (Lepidoptera: Bombycidae) have been domesticated and widely used for silk production. It feeds on mulberry leaves. Mulberry leaves are mainly composed of pectin, xylan, cellulose and starch. Some of the digestive enzymes that degrade these carbohydrates might be produced by gut bacteria. Eleven isolates were obtained from the digestive tract of B. mori, including the Gram positive Bacillus circulans and Gram negative Proteus vulgaris, Klebsiella pneumoniae, Escherichia coli, Citrobacter freundii, Serratia liquefaciens, Enterobacter sp., Pseudomonas fluorescens, P. aeruginosa, Aeromonas sp., and Erwinia sp.. Three of these isolates, P. vulgaris, K. pneumoniae, C. freundii, were cellulolytic and xylanolytic, P. fluorescens and Erwinia sp., were pectinolytic and K. pneumoniae degraded starch. Aeromonas sp. was able to utilize the CMcellulose and xylan. S. liquefaciens was able to utilize three polysaccharides including CMcellulose, xylan and pectin. B. circulans was able to utilize all four polysaccharides with different efficacy. The gut of B. mori has an alkaline pH and all of the isolated bacterial strains were found to grow and degrade polysaccharides at alkaline pH. The number of cellulolytic bacteria increases with each instar.

The bacteriological profile of the burned patients in the center of burns in CHU Mohamed VI Marrakech (about 123 cases)

PubMed Central

Benchamkha, Yassine; Dhaidah, Ouafaa; Dahazze, Adil; Meriem, Quaboul; Elamrani, Moulay Driss; Ettalbi, Salwa

2017-01-01

The bacterial nosocomial infection is one of the leading causes of morbidity and mortality for burned patient; we conducted a retrospective study of 123 patients hospitalized in the burns center CHUMED VI of Marrakechover a period of 3 years, from January 1st, 2013 to December 31st, 2016. The criteria for nosocomial infection were those of the Center for Disease Control in Atlanta in 1988. Incidence rates were calculated. The bacterial ecology of the department was described as also antibiotype. The predominancy of the population was male. The cumulative incidence was 103 infections per 1000 days of treatment. Regarding the characteristics of bacterial infections, infected sites were skin (69%), blood (18%), urinary tract (12%) and lungs (1%). The main organisms were: Staphylococcus sp. (37.7%), Pseudomonas aeruginosa (19.8%), Enterococcus faecalis and Proteus mirabilis (18.5%). Staphylococci were resistant méticillo-in 22% of cases. Pseudomonas and Acinetobacter were multi-resistant (66%). The establishment of the bacterial ecology of the service, helped us set the right rules of prescription of antibiotics, which was based on the infected site, the type of organism, its sensitivity, the molecule used and the pharmacokinetics particular patient burned. The two main organisms being Staphylococcus and Pseudomonas aeruginosa, antibiotics used in the Service will then beta-lactams, glycopeptides, fluoroquinolones and aminoglycosides. Finally, to control the epidemic risk posed by the emergence of resistant organisms is necessary to combine the practice of good antibiotic therapy and prevention. PMID:29119059

Rhizobacterial characterization for quality control of eucalyptus biogrowth promoter products.

PubMed

Zarpelon, Talyta Galafassi; Guimarães, Lúcio Mauro da Silva; Alfenas-Zerbini, Poliane; Lopes, Eli Sidney; Mafia, Reginaldo Gonçalves; Alfenas, Acelino Couto

Plant growth-promoting rhizobacteria strains from special formulations have been used to optimize eucalyptus cutting production. To undertake quality control for the formulated products, the rhizobacterial strains should be characterized to assess their purity and authentication. In the present study, we characterized nine strains of rhizobacteria, including three Bacillus subtilis (S1, S2 and 3918), two Pseudomonas sp. (MF4 and FL2), P. putida (MF2), P. fulva (Ca), Frateuria aurantia (R1), and Stenotrophomonas maltophilia (CIIb). The strains were differentiated by colony morphology after 24h of incubation in three different solid state culture media (glucose-nutritive agar, 523 medium and yeast extract-mannitol agar), sensitivity to a panel of 28 antibiotics (expressed according to the formation of inhibition halos of bacterial growth in the presence of antibiotics), and PCR-RFLP profiles of the 16S rDNA gene produced using nine restriction enzymes. It was possible to differentiate all nine strains of rhizobacteria using their morphological characteristics and sensitivity to antibiotics. The molecular analysis allowed us to separate the strains CIIb, FL2 and R1 from the strains belonging to the genera Bacillus and Pseudomonas. By using these three methods concomitantly, we were able to determine strain purity and perform the authentication. Copyright © 2016. Published by Elsevier Editora Ltda.

Marine Sponge-Derived Streptomyces sp. SBT343 Extract Inhibits Staphylococcal Biofilm Formation

PubMed Central

Balasubramanian, Srikkanth; Othman, Eman M.; Kampik, Daniel; Stopper, Helga; Hentschel, Ute; Ziebuhr, Wilma; Oelschlaeger, Tobias A.; Abdelmohsen, Usama R.

2017-01-01

Staphylococcus epidermidis and Staphylococcus aureus are opportunistic pathogens that cause nosocomial and chronic biofilm-associated infections. Indwelling medical devices and contact lenses are ideal ecological niches for formation of staphylococcal biofilms. Bacteria within biofilms are known to display reduced susceptibilities to antimicrobials and are protected from the host immune system. High rates of acquired antibiotic resistances in staphylococci and other biofilm-forming bacteria further hamper treatment options and highlight the need for new anti-biofilm strategies. Here, we aimed to evaluate the potential of marine sponge-derived actinomycetes in inhibiting biofilm formation of several strains of S. epidermidis, S. aureus, and Pseudomonas aeruginosa. Results from in vitro biofilm-formation assays, as well as scanning electron and confocal microscopy, revealed that an organic extract derived from the marine sponge-associated bacterium Streptomyces sp. SBT343 significantly inhibited staphylococcal biofilm formation on polystyrene, glass and contact lens surfaces, without affecting bacterial growth. The extract also displayed similar antagonistic effects towards the biofilm formation of other S. epidermidis and S. aureus strains tested but had no inhibitory effects towards Pseudomonas biofilms. Interestingly the extract, at lower effective concentrations, did not exhibit cytotoxic effects on mouse fibroblast, macrophage and human corneal epithelial cell lines. Chemical analysis by High Resolution Fourier Transform Mass Spectrometry (HRMS) of the Streptomyces sp. SBT343 extract proportion revealed its chemical richness and complexity. Preliminary physico-chemical characterization of the extract highlighted the heat-stable and non-proteinaceous nature of the active component(s). The combined data suggest that the Streptomyces sp. SBT343 extract selectively inhibits staphylococcal biofilm formation without interfering with bacterial cell viability. Due to absence of cell toxicity, the extract might represent a good starting material to develop a future remedy to block staphylococcal biofilm formation on contact lenses and thereby to prevent intractable contact lens-mediated ocular infections. PMID:28261188

Potential applications of Pseudomonas sp. (strain CPSB21) to ameliorate Cr6+ stress and phytoremediation of tannery effluent contaminated agricultural soils.

PubMed

Gupta, Pratishtha; Rani, Rupa; Chandra, Avantika; Kumar, Vipin

2018-03-20

Contamination of agricultural soil with heavy metals has become a serious concern worldwide. In the present study, Cr 6+ resistant plant growth promoting Pseudomonas sp. (strain CPSB21) was isolated from the tannery effluent contaminated agricultural soils and evaluated for the plant growth promoting activities, oxidative stress tolerance, and Cr 6+ bioremediation. Assessment of different plant growth promotion traits, such as phosphate solubilization, indole-3-acetic acid production, siderophores, ammonia and hydrogen cyanide production, revealed that the strain CPSB21 served as an efficient plant growth promoter under laboratory conditions. A pot experiment was performed using sunflower (Helianthus annuus L.) and tomato (Solanum lycopersicum L.) as a test crop. Cr 6+ toxicity reduced plant growth, pigment content, N and P uptake, and Fe accumulation. However, inoculation of strain CPSB21 alleviated the Cr 6+ toxicity and enhanced the plant growth parameters and nutrient uptake. Moreover, Cr toxicity had varied response on oxidative stress tolerance at graded Cr 6+ concentration on both plants. An increase in superoxide dismutase (SOD) and catalase (CAT) activity and reduction in malonialdehyde (MDA) was observed on inoculation of strain CPSB21. Additionally, inoculation of CPSB21 enhanced the uptake of Cr 6+ in sunflower plant, while no substantial enhancement was observed on inoculation in tomato plant.

Characterization and identification of the proteins bound to two types of polyhydroxyalkanoate granules in Pseudomonas sp. 61-3.

PubMed

Hokamura, Ayaka; Fujino, Kanako; Isoda, Yoshiko; Arizono, Koji; Shiratsuchi, Hideki; Matsusaki, Hiromi

2015-01-01

Pseudomonas sp. 61-3 accumulates two types of polyhydroxyalkanoates (PHAs), poly(3-hydroxybutyrate) [P(3HB)], and poly(3HB-co-3-hydroxyalkanoates) [P(3HB-co-3HA)], and some proteins associated with their PHA granules have been identified. To date, PhaFPs (GA36) and PhaIPs (GA18) were identified from P(3HB-co-3HA) granules. In this study, the gene encoding GA24 associated with P(3HB) granule was identified as phbPPs. PhbPPs was composed of 192 amino acids with a calculated molecular mass of 20.4 kDa and was assumed to be a phasin. phbFPs gene and unknown ORF were also found on phb locus. PhbFPs was anticipated to be the transcriptional repressor of phbPPs gene. PhbPPs was bound to the P(3HB-co-3HA) granules with 3HB composition of more than 87 mol%, and PhaIPs and PhaFPs were bound to the P(3HB-co-3HA) granules with 3HA (C6-C12) composition of more than 13 mol% in the producing cells, suggesting that localization of these proteins is attributed to the monomer compositions of the copolymers.

SecG is required for antibiotic activities of Pseudomonas sp. YL23 against Erwinia amylovora and Dickeya chrysanthemi.

PubMed

Liu, Youzhou; Baird, Sonya M; Qiao, Junqing; Du, Yan; Lu, Shi-En

2015-05-01

Strain YL23 was isolated from soybean root tips and identified to be Pseudomonas sp. This strain showed broad-spectrum antibacterial activity against bacterial pathogens that are economically important in agriculture. To characterize the genes dedicated to antibacterial activities against microbial phytopathogens, a Tn5-mutation library of YL23 was constructed. Plate bioassays revealed that the mutant YL23-93 lost its antibacterial activities against Erwinia amylovora and Dickeya chrysanthemi as compared with its wild type strain. Genetic and sequencing analyses localized the transposon in a homolog of the secG gene in the mutant YL23-93. Constitutive expression plasmid pUCP26-secG was constructed and electroporated into the mutant YL23-93. Introduction of the plasmid pUCP26-secG restored antibacterial activities of the mutant YL23-93 to E. amylovora and D. chrysanthemi. As expected, empty plasmid pUCP26 could not complement the phenotype of the antibacterial activity in the mutant. Thus the secG gene, belonging to the Sec protein translocation system, is required for antibacterial activity of strain YL23 against E. amylovora and D. chrysanthemi. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Conversion of chlorobiphenyls into phenylhexadienoates and benzoates by the enzymes of the upper pathway for polychlorobiphenyl degradation encoded by the bph locus of Pseudomonas sp. strain LB400.

PubMed Central

Seeger, M; Timmis, K N; Hofer, B

1995-01-01

Metabolism of 21 chlorobiphenyls by the enzymes of the upper biphenyl catabolic pathway encoded by the bph locus of Pseudomonas sp. strain LB400 was investigated by using recombinant strains harboring gene cassettes containing bphABC or bphABCD. The enzymes of the upper pathway were generally able to metabolize mono- and dichlorinated biphenyls but only partially transform most trichlorinated congeners investigated: 14 of 15 mono- and dichlorinated and 2 of 6 trichlorinated congeners were converted into benzoates. All mono- and at least 8 of 12 dichlorinated congeners were attacked by the bphA-encoded biphenyl dioxygenase virtually exclusively at ortho and meta carbons. This enzyme exhibited a high degree of selectivity for the aromatic ring to be attacked, with the order of ring preference being non- > ortho- > meta- > para-substituted for mono- and dichlorinated congeners. The influence of the chlorine substitution pattern of the metabolized ring on benzoate formation resembled its influence on the reactivity of initial dioxygenation, suggesting that the rate of benzoate formation may frequently be determined by the rate of initial attack. The absorption spectra of phenylhexadienoates formed correlated with the presence or absence of a chlorine substituent at an ortho position. PMID:7618878

A halotolerant thermostable lipase from the marine bacterium Oceanobacillus sp. PUMB02 with an ability to disrupt bacterial biofilms

PubMed Central

Seghal Kiran, George; Nishanth Lipton, Anuj; Kennedy, Jonathan; Dobson, Alan DW; Selvin, Joseph

2014-01-01

A halotolerant thermostable lipase was purified and characterized from the marine bacterium Oceanobacillus sp. PUMB02. This lipase displayed a high degree of stability over a wide range of conditions including pH, salinity, and temperature. It was optimally active at 30 °C and pH 8.0 respectively and was stable at higher temperatures (50–70 °C) and alkaline pH. The molecular mass of the lipase was approximately 31 kDa based on SDS-PAGE and MALDI-ToF fingerprint analysis. Conditions for enhanced production of lipase by Oceanobacillus sp. PUMB02 were attained in response surface method-guided optimization with factors such as olive oil, sucrose, potassium chromate, and NaCl being evaluated, resulting in levels of 58.84 U/ml being achieved. The biofilm disruption potential of the PUMB02 lipase was evaluated and compared with a marine sponge metagenome derived halotolerant lipase Lpc53E1. Good biofilm disruption activity was observed with both lipases against potential food pathogens such as Bacillus cereus MTCC1272, Listeria sp. MTCC1143, Serratia sp. MTCC4822, Escherichia coli MTCC443, Pseudomonas fluorescens MTCC1748, and Vibrio parahemolyticus MTCC459. Phase contrast microscopy, scanning electron microscopy, and confocal laser scanning microscopy showed very effective disruption of pathogenic biofilms. This study reveals that marine derived hydrolytic enzymes such as lipases may have potential utility in inhibiting biofilm formation in a food processing environment and is the first report of the potential application of lipases from the genus Oceanobacillus in biofilm disruption strategies. PMID:25482232

Cr isotope fractionation factors for Cr(VI) reduction by a metabolically diverse group of bacteria

NASA Astrophysics Data System (ADS)

Basu, Anirban; Johnson, Thomas M.; Sanford, Robert A.

2014-10-01

Reduction of Cr(VI) is an important process that determines the geochemical behavior, mobility and bioavailability of Cr in both terrestrial and marine environments. Many metabolically diverse microorganisms possess Cr(VI) reduction capacity. Cr(VI) reduction fractionates Cr isotopes and thus 53Cr/52Cr ratios can be used to monitor Cr(VI) reduction and redox conditions. The magnitude of isotopic fractionation (ε) for a variety of microbial reduction mechanisms must be known for accurate interpretation of observed shifts in 53Cr/52Cr ratios. We determined isotopic fractionation factors for Cr(VI) reduction by metal reducers Geobacter sulfurreducens and Shewanella sp. strain NR, a denitrifying soil bacterium Pseudomonas stutzeri DCP-Ps1, and a sulfate reducer Desulfovibrio vulgaris. All bacteria investigated in this study produced significant Cr isotope fractionation. The fractionation (ε) for G. sulfurreducens, Shewanella sp. (NR), P. stutzeri DCP-Ps1, and D. vulgaris were -3.03‰ ± 0.12‰, -2.17‰ ± 0.22‰, -3.14‰ ± 0.13‰, and -3.01‰ ± 0.11‰, respectively. Despite differences in microbial strains in this study, the ε did not vary significantly except for Shewanella sp. (NR). Our results suggest that strong isotopic fractionation is induced during Cr(VI) reduction under electron donor poor (∼300 μM) conditions.