Carbon Catabolite Repression and Impranil Polyurethane Degradation in Pseudomonas protegens Strain Pf-5.

PubMed

Hung, Chia-Suei; Zingarelli, Sandra; Nadeau, Lloyd J; Biffinger, Justin C; Drake, Carrie A; Crouch, Audra L; Barlow, Daniel E; Russell, John N; Crookes-Goodson, Wendy J

2016-10-15

Polyester polyurethane (PU) coatings are widely used to help protect underlying structural surfaces but are susceptible to biological degradation. PUs are susceptible to degradation by Pseudomonas species, due in part to the degradative activity of secreted hydrolytic enzymes. Microorganisms often respond to environmental cues by secreting enzymes or secondary metabolites to benefit their survival. This study investigated the impact of exposing several Pseudomonas strains to select carbon sources on the degradation of the colloidal polyester polyurethane Impranil DLN (Impranil). The prototypic Pseudomonas protegens strain Pf-5 exhibited Impranil-degrading activities when grown in sodium citrate but not in glucose-containing medium. Glucose also inhibited the induction of Impranil-degrading activity by citrate-fed Pf-5 in a dose-dependent manner. Biochemical and mutational analyses identified two extracellular lipases present in the Pf-5 culture supernatant (PueA and PueB) that were involved in degradation of Impranil. Deletion of the pueA gene reduced Impranil-clearing activities, while pueB deletion exhibited little effect. Removal of both genes was necessary to stop degradation of the polyurethane. Bioinformatic analysis showed that putative Cbr/Hfq/Crc-mediated regulatory elements were present in the intergenic sequences upstream of both pueA and pueB genes. Our results confirmed that both PueA and PueB extracellular enzymes act in concert to degrade Impranil. Furthermore, our data showed that carbon sources in the growth medium directly affected the levels of Impranil-degrading activity but that carbon source effects varied among Pseudomonas strains. This study uncovered an intricate and complicated regulation of P. protegens PU degradation activity controlled by carbon catabolite repression. Polyurethane (PU) coatings are commonly used to protect metals from corrosion. Microbiologically induced PU degradation might pose a substantial problem for the integrity

Isolation of bisphenol A-tolerant/degrading Pseudomonas monteilii strain N-502.

PubMed

Masuda, Midori; Yamasaki, Yoshiki; Ueno, Shun; Inoue, Akira

2007-03-01

Bisphenol A (BPA) is a highly biotoxic compound that kills many microorganisms at a low concentration (1,000 ppm). We isolated BPA-tolerant/degrading Pseudomonas monteilii strain N-502 from about 1,000 samples collected from a field, sewage, and pond water. The isolated strain had strong BPA tolerance and high BPA-degrading activity. This strain was able to grow in a minimum medium containing BPA as the sole carbon source. Strain N-502 is an aerobic, motile, gram-negative, nonspore-forming, rod-shaped bacterium and was identified as P. monteilii, based on 16 S rRNA gene analysis. Strain N-502 completely degraded BPA 500 ppm in a 10-day, in culture system and was able to degrade BPA 100 ppm in a 2-h resting cell system. This strain also showed potent ability to degrade BPA 500 and 1,000 ppm in the resting cell system. Moreover, the initial BPA degradation rate was accelerated with the addition of Ca(2+), Mg(2+), and folic acid.

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

Benzene and Naphthalene Degrading Bacterial Communities in an Oil Sands Tailings Pond

PubMed Central

Rochman, Fauziah F.; Sheremet, Andriy; Tamas, Ivica; Saidi-Mehrabad, Alireza; Kim, Joong-Jae; Dong, Xiaoli; Sensen, Christoph W.; Gieg, Lisa M.; Dunfield, Peter F.

2017-01-01

Oil sands process-affected water (OSPW), produced by surface-mining of oil sands in Canada, is alkaline and contains high concentrations of salts, metals, naphthenic acids, and polycyclic aromatic compounds (PAHs). Residual hydrocarbon biodegradation occurs naturally, but little is known about the hydrocarbon-degrading microbial communities present in OSPW. In this study, aerobic oxidation of benzene and naphthalene in the surface layer of an oil sands tailings pond were measured. The potential oxidation rates were 4.3 μmol L−1 OSPW d−1 for benzene and 21.4 μmol L−1 OSPW d−1 for naphthalene. To identify benzene and naphthalene-degrading microbial communities, metagenomics was combined with stable isotope probing (SIP), high-throughput sequencing of 16S rRNA gene amplicons, and isolation of microbial strains. SIP using 13C-benzene and 13C-naphthalene detected strains of the genera Methyloversatilis and Zavarzinia as the main benzene degraders, while strains belonging to the family Chromatiaceae and the genus Thauera were the main naphthalene degraders. Metagenomic analysis revealed a diversity of genes encoding oxygenases active against aromatic compounds. Although these genes apparently belonged to many phylogenetically diverse taxa, only a few of these taxa were predominant in the SIP experiments. This suggested that many members of the community are adapted to consuming other aromatic compounds, or are active only under specific conditions. 16S rRNA gene sequence datasets have been submitted to the Sequence Read Archive (SRA) under accession number SRP109130. The Gold Study and Project submission ID number in Joint Genome Institute IMG/M for the metagenome is Gs0047444 and Gp0055765. PMID:29033909

Catabolism of Naphthalenesulfonic Acids by Pseudomonas sp. A3 and Pseudomonas sp. C22

PubMed Central

Brilon, C.; Beckmann, W.; Knackmuss, H.-J.

1981-01-01

Naphthalene and two naphthalenesulfonic acids were degraded by Pseudomonas sp. A3 and Pseudomonas sp. C22 by the same enzymes. Gentisate is a major metabolite. Catabolic activities for naphthalene, 1-naphthalenesulfonic acid, and 2-naphthalenesulfonic acid are induced by growth with naphthalene, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, methylnaphthalene, or salicylate. Gentisate is also an inducer in strain A3. Inhibition kinetics show that naphthalene and substituted naphthalenes are hydroxylated by the same naphthalene dioxygenase. Substrates with nondissociable substituents such as CH3, OCH3, Cl, or NO2 are hydroxylated in the 7,8-position, and 4-substituted salicylates are accumulated. If CO2H, CH2CO2H, or SO3H are substituents, hydroxylation occurs with high regioselectivity in the 1,2-position. Thus, 1,2-dihydroxy-1,2-dihydronaphthalene-2-carboxylic acids are formed quantitatively from the corresponding naphthalenecarboxylic acids. Utilization of naphthalenesulfonic acids proceeds by the same regioselective 1,2-dioxygenation which labilizes the C—SO3− bond and eliminates sulfite. PMID:16345814

Sulfate-Reducing Naphthalene Degraders Are Picky Eaters.

PubMed

Wolfson, Sarah J; Porter, Abigail W; Kerkhof, Lee J; McGuinness, Lora M; Prince, Roger C; Young, Lily Y

2018-06-25

Polycyclic aromatic hydrocarbons (PAHs) are common organic contaminants found in anoxic environments. The capacity for PAH biodegradation in unimpacted environments, however, has been understudied. Here we investigate the enrichment, selection, and sustainability of a microbial community from a pristine environment on naphthalene as the only amended carbon source. Pristine coastal sediments were obtained from the Jacques Cousteau National Estuarine Research Reserve in Tuckerton, New Jersey, an ecological reserve which has no direct input or source of hydrocarbons. After an initial exposure to naphthalene, primary anaerobic transfer cultures completely degraded 500 µM naphthalene within 139 days. Subsequent transfer cultures mineralized naphthalene within 21 days with stoichiometric sulfate loss. Enriched cultures efficiently utilized only naphthalene and 2-methylnaphthalene from the hydrocarbon mixtures in crude oil. To determine the microorganisms responsible for naphthalene degradation, stable isotope probing was utilized on cultures amended with fully labeled 13 C-naphthalene as substrate. Three organisms were found to unambiguously synthesize 13 C-DNA from 13 C-naphthalene within 7 days. Phylogenetic analysis revealed that 16S rRNA genes from two of these organisms are closely related to the known naphthalene degrading isolates NaphS2 and NaphS3 from PAH-contaminated sites. A third 16S rRNA gene was only distantly related to its closest relative and may represent a novel naphthalene degrading microbe from this environment.

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.

Enrichment and characterization of sulfate reducing, naphthalene degrading microorganisms

NASA Astrophysics Data System (ADS)

Steffen, Kümmel; Florian-Alexander, Herbst; Márcia, Duarte; Dietmar, Pieper; Jana, Seifert; Bergen Martin, von; Hans-Hermann, Richnow; Carsten, Vogt

2014-05-01

Polycyclic aromatic hydrocarbons (PAH) are pollutants of great concern due to their potential toxicity, mutagenicity and carcinogenicity. PAH are widely distributed in the environment by accidental discharges during the transport, use and disposal of petroleum products, and during forest and grass fires. Caused by their hydrophobic nature, PAH basically accumulate in sediments from where they are slowly released into the groundwater. Although generally limited by the low water solubility of PAH, microbial degradation is one of the major mechanisms leading to the complete clean-up of PAH-contaminated sites. Whereas organisms and biochemical pathways responsible for the aerobic breakdown of PAH are well known, anaerobic PAH biodegradation is less understood; only a few anaerobic PAH degrading cultures have been described. We studied the anaerobic PAH degradation in a microcosm approach to enrich anaerobic PAH degraders. Anoxic groundwater and sediment samples were used as inoculum. Groundwater samples were purchased from the erstwhile gas works facility and a former wood impregnation site. In contrast, sources of sediment samples were a former coal refining area and an old fuel depot. Samples were incubated in anoxic mineral salt medium with naphthalene as sole carbon source and sulfate as terminal electron acceptor. Grown cultures were characterized by feeding with 13C-labeled naphthalene, 16S rRNA gene sequencing using an Illumina® approach, and functional proteome analyses. Finally, six enrichment cultures able to degrade naphthalene under anoxic conditions were established. First results point to a dominance of identified sequences affiliated to the freshwater sulfate-reducing strain N47, which is a known anaerobic naphthalene degrader, in four out of the six enrichments. In those enrichments, peptides related to the pathway of anoxic naphthalene degradation in N47 were abundant. Overall the data underlines the importance of Desulfobacteria for natural

Degradation of naphthalene-2,6- and naphthalene-1,6-disulfonic acid by a Moraxella sp

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

Wittich, R.M.; Tast, H.G.; Knackmuss, H.J.

1988-07-01

A naphthalene-2,6-disulfonic acid (2,6NDS)-degrading Moraxella strain was isolated from an industrial sewage plant. This culture could also be adapted to naphthalene-1,6-disulfonic acid as growth substrate. Regioselective 1,2-dioxygenation effected desulfonation and catabolism to 5-sulfosalicylic acid (5SS), which also could be used a the sole carbon source. 5SS-grown cells exhibited high gentisate 1,2-dioxygenase activity. Neither 5SS- nor gentisate-grown cells oxidized 2,6NDS; therefore, 2,6NDS or an early metabolite must serve as an inducer of the initial catabolic enzymes(s).

SEQUENCE SIMILARITIES IN THE GENES ENCODING POLY- CHLORINATED BIPHENYL DEGRADATION BY PSEUDOMONAS STRAIN LB400 AND ALCALIGENES EUTROPHUS H850

EPA Science Inventory

DNA-DNA hybridization was used to compare the Pseudomonas strain LB400 genes for polychlorinated biphenyl (PCB) degradation with those from seven other PCB-degrading strains. Significant hybridization was detected to the genome of Alcaligenes eutrophus H850, a strain similar to L...

Degradation of paracetamol by Pseudomonas aeruginosa strain HJ1012.

PubMed

Hu, Jun; Zhang, Li L; Chen, Jian M; Liu, Yu

2013-01-01

Pseudomonas aeruginosa strain HJ1012 was isolated on paracetamol as a sole carbon and energy source. This organism could completely degrade paracetamol as high as 2200 mg/L. Following paracetamol consumption, a CO₂ yield rate up to 71.4% proved that the loss of paracetamol was mainly via mineralization. Haldane's equation adequately described the relationship between the specific growth rate and substrate concentration. The maximum specific growth rate and yield coefficient were 0.201 g-Paracetamol/g-VSS·h and 0.101 mg of biomass yield/mg of paracetamol consumed, respectively. A total of 8 metabolic intermediates was identified and classified into aromatic compounds, carboxylic acids, and inorganic species (nitrite and nitrate ions). P-aminophenol and hydroquinone are the two key metabolites of the initial steps in the paracetamol catabolic pathway. Paracetamol is degraded predominantly via p-aminophenol to hydroquinone with subsequent ring fission, suggesting partially new pathways for paracetamol-degrading bacteria.

Strategy of Pseudomonas pseudoalcaligenes C70 for effective degradation of phenol and salicylate

PubMed Central

Heinaru, Eeva; Naanuri, Eve; Mehike, Maris; Leito, Ivo; Heinaru, Ain

2017-01-01

Phenol- and naphthalene-degrading indigenous Pseudomonas pseudoalcaligenes strain C70 has great potential for the bioremediation of polluted areas. It harbours two chromosomally located catechol meta pathways, one of which is structurally and phylogenetically very similar to the Pseudomonas sp. CF600 dmp operon and the other to the P. stutzeri AN10 nah lower operon. The key enzymes of the catechol meta pathway, catechol 2,3-dioxygenase (C23O) from strain C70, PheB and NahH, have an amino acid identity of 85%. The metabolic and regulatory phenotypes of the wild-type and the mutant strain C70ΔpheB lacking pheB were evaluated. qRT-PCR data showed that in C70, the expression of pheB- and nahH-encoded C23O was induced by phenol and salicylate, respectively. We demonstrate that strain C70 is more effective in the degradation of phenol and salicylate, especially at higher substrate concentrations, when these compounds are present as a mixture; i.e., when both pathways are expressed. Moreover, NahH is able to substitute for the deleted PheB in phenol degradation when salicylate is also present in the growth medium. The appearance of a yellow intermediate 2-hydroxymuconic semialdehyde was followed by the accumulation of catechol in salicylate-containing growth medium, and lower expression levels and specific activities of the C23O of the sal operon were detected. However, the excretion of the toxic intermediate catechol to the growth medium was avoided when the growth medium was supplemented with phenol, seemingly due to the contribution of the second meta pathway encoded by the phe genes. PMID:28257519

2,4-Dinitrotoluene dioxygenase from Burkholderia sp. strain DNT: similarity to naphthalene dioxygenase.

PubMed Central

Suen, W C; Haigler, B E; Spain, J C

1996-01-01

2,4-Dinitrotoluene (DNT) dioxygenase from Burkholderia sp. strain DNT catalyzes the initial oxidation of DNT to form 4-methyl-5-nitrocatechol (MNC) and nitrite. The displacement of the aromatic nitro group by dioxygenases has only recently been described, and nothing is known about the evolutionary origin of the enzyme systems that catalyze these reactions. We have shown previously that the gene encoding DNT dioxygenase is localized on a degradative plasmid within a 6.8-kb NsiI DNA fragment (W.-C. Suen and J. C. Spain, J. Bacteriol. 175:1831-1837, 1993). We describe here the sequence analysis and the substrate range of the enzyme system encoded by this fragment. Five open reading frames were identified, four of which have a high degree of similarity (59 to 78% identity) to the components of naphthalene dioxygenase (NDO) from Pseudomonas strains. The conserved amino acid residues within NDO that are involved in cofactor binding were also identified in the gene encoding DNT dioxygenase. An Escherichia coli clone that expressed DNT dioxygenase converted DNT to MNC and also converted naphthalene to (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. In contrast, the E. coli clone that expressed NDO did not oxidize DNT. Furthermore, the enzyme systems exhibit similar broad substrate specificities and can oxidize such compounds as indole, indan, indene, phenetole, and acenaphthene. These results suggest that DNT dioxygenase and the NDO enzyme system share a common ancestor. PMID:8759857

Squamocin, an annonaceous acetogenin, enhances naphthalene degradation mediated by Bacillus atrophaeus CN4.

PubMed

Parellada, Eduardo A; Igarza, Mercedes; Isacc, Paula; Bardón, Alicia; Ferrero, Marcela; Ameta, Keshav Lalit; Neske, Adriana

Squamocin belongs to a group of compounds called annonaceous acetogenins. They are secondary products of Annonaceae metabolism and can be isolated from Annona cherimolia seeds. This paper deals with the stimulation of biofilm formation of Bacillus atrophaeus CN4 by employing low squamocin concentrations to increase naphthalene degradation. Bacillus atrophaeus CN4, isolated from contaminated soil, has the ability to degrade naphthalene as the only source of carbon and energy. In the absence of additional carbon sources, the strain removed 69% of the initial concentration of naphthalene (approx. 0.2mmol/l) in the first 12h of incubation. The addition of squamocin in LB medium stimulated Bacillus atrophaeus CN4 biofilm formation and enhanced naphthalene removal. Squamocin (2.5μg/ml) does not affect planktonic growth and therefore, the observed increases are solely due to the stimulation of biofilm formation. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Characterization of a Pyrethroid-Degrading Pseudomonas fulva Strain P31 and Biochemical Degradation Pathway of D-Phenothrin.

PubMed

Yang, Jingjing; Feng, Yanmei; Zhan, Hui; Liu, Jie; Yang, Fang; Zhang, Kaiyang; Zhang, Lianhui; Chen, Shaohua

2018-01-01

D-phenothrin is one of the most popular pyrethroid insecticides for its broad spectrum and high insecticidal activity. However, continuous use of D-phenothrin has resulted in serious environmental contamination and raised public concern about its impact on human health. Biodegradation of D-phenothrin has never been investigated and its metabolic behaviors remain unknown. Here, a novel bacterial strain P31 was isolated from active sludge, which completely degraded (100%) D-phenothrin at 50 mg⋅L -1 in 72 h. Based on the morphology, 16S rRNA gene and Biolog tests, the strain was identified as Pseudomonas fulva . Biodegradation conditions were optimized as 29.5°C and pH 7.3 by utilizing response surface methodology. Strain P31 depicted high tolerance and strong D-phenothrin degradation ability through hydrolysis pathway. Strain P31 degraded D-phenothrin at inhibition constant ( K i ) of 482.1673 mg⋅L -1 and maximum specific degradation constant ( q max ) of 0.0455 h -1 whereas critical inhibitor concentration remained as 41.1189 mg⋅L -1 . The 3-Phenoxybenzaldehyde and 1,2-benzenedicarboxylic butyl dacyl ester were identified as the major intermediate metabolites of D-phenothrin degradation pathway through high-performance liquid chromatography and gas chromatography-mass spectrometry. Bioaugmentation of D-phenothrin-contaminated soils with strain P31 dramatically enhanced its degradation, and over 75% of D-phenothrin was removed from soils within 10 days. Moreover, the strain illustrated a remarkable capacity to degrade other synthetic pyrethroids, including permethrin, cyhalothrin, β-cypermethrin, deltamethrin, fenpropathrin, and bifenthrin, exhibiting great potential in bioremediation of pyrethroid-contaminated environment.

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.

Characterization and Genome Analysis of a Nicotine and Nicotinic Acid-Degrading Strain Pseudomonas putida JQ581 Isolated from Marine.

PubMed

Li, Aiwen; Qiu, Jiguo; Chen, Dongzhi; Ye, Jiexu; Wang, Yuhong; Tong, Lu; Jiang, Jiandong; Chen, Jianmeng

2017-05-31

The presence of nicotine and nicotinic acid (NA) in the marine environment has caused great harm to human health and the natural environment. Therefore, there is an urgent need to use efficient and economical methods to remove such pollutants from the environment. In this study, a nicotine and NA-degrading bacterium-strain JQ581-was isolated from sediment from the East China Sea and identified as a member of Pseudomonas putida based on morphology, physio-biochemical characteristics, and 16S rDNA gene analysis. The relationship between growth and nicotine/NA degradation suggested that strain JQ581 was a good candidate for applications in the bioaugmentation treatment of nicotine/NA contamination. The degradation intermediates of nicotine are pseudooxynicotine (PN) and 3-succinoyl-pyridine (SP) based on UV, high performance liquid chromatography, and liquid chromatography-mass spectrometry analyses. However, 6-hydroxy-3-succinoyl-pyridine (HSP) was not detected. NA degradation intermediates were identified as 6-hydroxynicotinic acid (6HNA). The whole genome of strain JQ581 was sequenced and analyzed. Genome sequence analysis revealed that strain JQ581 contained the gene clusters for nicotine and NA degradation. This is the first report where a marine-derived Pseudomonas strain had the ability to degrade nicotine and NA simultaneously.

Degradation pathway of 2-chloroethanol in Pseudomonas stutzeri strain JJ under denitrifying conditions.

PubMed

Dijk, John A; Gerritse, Jan; Schraa, Gosse; Stams, Alfons J M

2004-12-01

The pathway of 2-chloroethanol degradation in the denitrifying Pseudomonas stutzeri strain JJ was investigated. In cell-free extracts, activities of a phenazine methosulfate (PMS)-dependent chloroethanol dehydrogenase, an NAD-dependent chloroacetaldehyde dehydrogenase, and a chloroacetate dehalogenase were detected. This suggested that the 2-chloroethanol degradation pathway in this denitrifying strain is the same as found in aerobic bacteria that degrade chloroethanol. Activity towards primary alcohols, secondary alcohols, diols, and other chlorinated alcohols could be measured in cell-free extracts with chloroethanol dehydrogenase (CE-DH) activity. PMS and phenazine ethosulfate (PES) were used as primary electron acceptors, but not NAD, NADP or ferricyanide. Cells of strain JJ cultured in a continuous culture under nitrate limitation exhibited chloroethanol dehydrogenase activity that was a 12 times higher than in cells grown in batch culture. However, under chloroethanol-limiting conditions, CE-DH activity was in the same range as in batch culture. Cells grown on ethanol did not exhibit CE-DH activity. Instead, NAD-dependent ethanol dehydrogenase (E-DH) activity and PMS-dependent E-DH activity were detected.

Induction of bphA, encoding biphenyl dioxygenase, in two polychlorinated biphenyl-degrading bacteria, psychrotolerant Pseudomonas strain Cam-1 and mesophilic Burkholderia strain LB400.

PubMed

Master, E R; Mohn, W W

2001-06-01

We investigated induction of biphenyl dioxygenase in the psychrotolerant polychlorinated biphenyl (PCB) degrader Pseudomonas strain Cam-1 and in the mesophilic PCB degrader Burkholderia strain LB400. Using a counterselectable gene replacement vector, we inserted a lacZ-Gm(r) fusion cassette between chromosomal genes encoding the large subunit (bphA) and small subunit (bphE) of biphenyl dioxygenase in Cam-1 and LB400, generating Cam-10 and LB400-1, respectively. Potential inducers of bphA were added to cell suspensions of Cam-10 and LB400-1 incubated at 30 degrees C, and then beta-galactosidase activity was measured. Biphenyl induced beta-galactosidase activity in Cam-10 to a level approximately six times greater than the basal level in cells incubated with pyruvate. In contrast, the beta-galactosidase activities in LB400-1 incubated with biphenyl and in LB400-1 incubated with pyruvate were indistinguishable. At a concentration of 1 mM, most of the 40 potential inducers tested were inhibitory to induction by biphenyl of beta-galactosidase activity in Cam-10. The exceptions were naphthalene, salicylate, 2-chlorobiphenyl, and 4-chlorobiphenyl, which induced beta-galactosidase activity in Cam-10, although at levels that were no more than 30% of the levels induced by biphenyl. After incubation for 24 h at 7 degrees C, biphenyl induced beta-galactosidase activity in Cam-10 to a level approximately four times greater than the basal level in cells incubated with pyruvate. The constitutive level of beta-galactosidase activity in LB400-1 grown at 15 degrees C was approximately five times less than the level in LB400-1 grown at 30 degrees C. Thus, there are substantial differences in the effects of physical and chemical environmental conditions on genetic regulation of PCB degradation in different bacteria.

Isolation and characterization of a pseudomonas strain that degrades 4-acetamidophenol and 4-aminophenol.

PubMed

Ahmed, S; Javed, M A; Tanvir, S; Hameed, A

2001-01-01

Though many microorganisms that are capable of using phenol as sole source of carbon have been isolated and characterized, only a few organisms degrading substituted phenols have been described to date. In this study, one strain of microorganism that is capable of using phenol (3,000 ppm), 4-aminophenol (4,000 ppm) and 4-acetamidophenol (4,000 ppm) as sole source of carbon and energy was isolated and characterized. This strain was obtained by enrichment culture from a site contaminated with compounds like 4-acetamidophenol, 4-aminophenol and phenol in Pakistan at Bhai Pheru. The contaminated site is able to support large bacterial community as indicated by the viable cell counts (2 x 10(4) - 5 x 10(8)) per gram of soil. Detailed taxonomic studies identified the organisms as Pseudomonas species designated as strain STI. The isolate also showed growth on other organic compounds like aniline, benzene, benzyl alcohol, benzyl bromide, toluene, p-cresol, trichloroethylene and o-xylene. Optimum growth temperature and pH were found to be 30 degrees C and 7, respectively, while growth at 4, 25 and 35 degrees C and at pH 8 and 9 was also observed. Non growing suspended cells of strain ST1 degraded 68, 96 and 76.8% of 4-aminophenol (1,000 ppm), phenol (500 ppm) and 4-acetamidophenol (1,000 ppm), respectively, in 72 hrs. The isolation and characterization of Pseudomonas species strain STI, may contribute to efforts on phenolic bioremediation, particularly in an environment with very high levels of 4-acetamidophenol and 4-aminophenol.

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).

Measurement of Biologically Available Naphthalene in Gas and Aqueous Phases by Use of a Pseudomonas putida Biosensor

PubMed Central

Werlen, Christoph; Jaspers, Marco C. M.; van der Meer, Jan Roelof

2004-01-01

Genetically constructed microbial biosensors for measuring organic pollutants are mostly applied in aqueous samples. Unfortunately, the detection limit of most biosensors is insufficient to detect pollutants at low but environmentally relevant concentrations. However, organic pollutants with low levels of water solubility often have significant gas-water partitioning coefficients, which in principle makes it possible to measure such compounds in the gas rather than the aqueous phase. Here we describe the first use of a microbial biosensor for measuring organic pollutants directly in the gas phase. For this purpose, we reconstructed a bioluminescent Pseudomonas putida naphthalene biosensor strain to carry the NAH7 plasmid and a chromosomally inserted gene fusion between the sal promoter and the luxAB genes. Specific calibration studies were performed with suspended and filter-immobilized biosensor cells, in aqueous solution and in the gas phase. Gas phase measurements with filter-immobilized biosensor cells in closed flasks, with a naphthalene-contaminated aqueous phase, showed that the biosensor cells can measure naphthalene effectively. The biosensor cells on the filter responded with increasing light output proportional to the naphthalene concentration added to the water phase, even though only a small proportion of the naphthalene was present in the gas phase. In fact, the biosensor cells could concentrate a larger proportion of naphthalene through the gas phase than in the aqueous suspension, probably due to faster transport of naphthalene to the cells in the gas phase. This led to a 10-fold lower detectable aqueous naphthalene concentration (50 nM instead of 0.5 μM). Thus, the use of bacterial biosensors for measuring organic pollutants in the gas phase is a valid method for increasing the sensitivity of these valuable biological devices. PMID:14711624

Enhanced polyaromatic hydrocarbon degradation by adapted cultures of actinomycete strains.

PubMed

Bourguignon, Natalia; Isaac, Paula; Alvarez, Héctor; Amoroso, María J; Ferrero, Marcela A

2014-12-01

Fifteen actinomycete strains were evaluated for their potential use in removal of polycyclic aromatic hydrocarbons (PAH). Their capability to degrade of naphthalene, phenanthrene, and pyrene was tested in minimal medium (MM) and MM with glucose as another substrate. Degradation of naphthalene in MM was observed in all isolates at different rates, reaching maximum values near to 76% in some strains of Streptomyces, Rhodococcus sp. 016 and Amycolatopsis tucumanensis DSM 45259. Maximum values of degradation of phenanthrene in MM occurred in cultures of A. tucumanensis DSM 45259 (36.2%) and Streptomyces sp. A12 (20%), while the degradation of pyrene in MM was poor and only significant with Streptomyces sp. A12 (4.3%). Because of the poor performance when growing on phenanthrene and pyrene alone, Rhodococcus sp. 20, Rhodococcus sp. 016, A. tucumanensis DSM 45259, Streptomyces sp. A2, and Streptomyces sp. A12 were challenged to an adaptation schedule of successive cultures on a fresh solid medium supplemented with PAHs, decreasing concentration of glucose in each step. As a result, an enhanced degradation of PAHs by adapted strains was observed in the presence of glucose as co-substrate, without degradation of phenanthrene and pyrene in MM while an increase to up to 50% of degradation was seen with these strains in glucose amended media. An internal fragment of the catA gene, which codes for catechol 1,2-dioxygenase, was amplified from both Rhodococcus strains, showing the potential for degradation of aromatic compounds via salycilate. These results allow us to propose the usefulness of these actinomycete strains for PAH bioremediation in the environment. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Chemotaxis to furan compounds by furan-degrading Pseudomonas strains

USDA-ARS?s Scientific Manuscript database

Two Pseudomonas strains known to utilize furan derivatives were shown to be attracted to furfural, 5-hydroxymethylfurfural, furfuryl alcohol, and 2-furoic acid in the absence of furan metabolism. In addition, a LysR-family regulatory protein known to regulate furan metabolic genes was found to be i...

KINETICS OF CHROMATE REDUCTION DURING NAPHTHALENE DEGRADATION IN A MIXED CULTURE

EPA Science Inventory

A mixed culture of Bacillus sp. K1 and Sphingomonas paucimobilis EPA 505 was exposed to chromate and naphthalene. Batch experiments showed that chromate was reduced and naphthalene was degraded by the mixed culture. Chromate reduction occurred initially at a high rate followed by...

Naphthalene and benzene degradation under Fe(III)-reducing conditions in petroleum-contaminated aquifers

USGS Publications Warehouse

Anderson, Robert T.; Lovely, Derek R.

1999-01-01

Naphthalene was oxidized anaerobically to CO2 in sediments collected from a petroleum-contaminated aquifer in Bemidji, Minnesota in which Fe(III) reduction was the terminal electron-accepting process. Naphthalene was not oxidized in sediments from the methanogenic zone at Bemidji or in sediments from the Fe(III)-reducing zone of other petroleum-contaminated aquifers studied. In a profile across the Fe(III)-reducing zone of the Bemidji aquifer, rates of naphthalene oxidation were fastest in sediments with the highest proportion of Fe(III), which was also the zone of the most rapid degradation of benzene, toluene, and acetate. The comparative studies attempted to elucidate factors that might account for the fact that unsubstituted aromatic hydrocarbons such as benzene and naphthalene were degraded under Fe(III)-reducing conditions at Bemidji, but not at the other aquifers examined. These studies indicated that the ability of Fe(III)-reducing microorganisms to degrade benzene and naphthalene at the Bemidji site cannot be attributed to groundwater components that make Fe(III) more available for reduction or other potential factors that were evaluated. However, unlike the other aquifers evaluated, uncontaminated sediments at the Bemidji site could be adapted for anaerobic benzene degradation merely with the addition of benzene. These findings indicate that Bemidji sediments naturally contain Fe(III) reducers capable of degradation of unsubstituted aromatic hydrocarbons.

NUCLEOTIDE SEQUENCING AND TRANSCRIPTIONAL MAPPING OF THE GENES ENCODING BIPHENYL DIOXYGENASE, A MULTICOMPONENT POLYCHLORINATED-BIPHENYL-DEGRADING ENZYME IN PSEUDOMONAS STRAIN LB400

EPA Science Inventory

The DNA region encoding biphenyl dioxygenase, the first enzyme in the biphenyl-polychlorinated biphenyl degradation pathway of Pseudomonas species strain LB400, was sequenced. ix open reading frames were identified, four of which are, homologous to the components of toluene dioxy...

Characterization of a Polycyclic Aromatic Hydrocarbon Degradation Gene Cluster in a Phenanthrene-Degrading Acidovorax Strain▿

PubMed Central

Singleton, David R.; Guzmán Ramirez, Liza; Aitken, Michael D.

2009-01-01

Acidovorax sp. strain NA3 was isolated from polycyclic aromatic hydrocarbon (PAH)-contaminated soil that had been treated in a bioreactor and enriched with phenanthrene. The 16S rRNA gene of the isolate possessed 99.8 to 99.9% similarity to the dominant sequences recovered during a previous stable-isotope probing experiment with [U-13C]phenanthrene on the same soil (D. R. Singleton, S. N. Powell, R. Sangaiah, A. Gold, L. M. Ball, and M. D. Aitken, Appl. Environ. Microbiol. 71:1202-1209, 2005). The strain grew on phenanthrene as a sole carbon and energy source and could mineralize 14C from a number of partially labeled PAHs, including naphthalene, phenanthrene, chrysene, benz[a]anthracene, and benzo[a]pyrene, but not pyrene or fluoranthene. Southern hybridizations of a genomic fosmid library with a fragment of the large subunit of the ring-hydroxylating dioxygenase gene from a naphthalene-degrading Pseudomonas strain detected the presence of PAH degradation genes subsequently determined to be highly similar in both nucleotide sequence and gene organization to an uncharacterized Alcaligenes faecalis gene cluster. The genes were localized to the chromosome of strain NA3. To test for gene induction by selected compounds, RNA was extracted from amended cultures and reverse transcribed, and cDNA associated with the enzymes involved in the first three steps of phenanthrene degradation was quantified by quantitative real-time PCR. Expression of each of the genes was induced most strongly by phenanthene and to a lesser extent by naphthalene, but other tested PAHs and PAH metabolites had negligible effects on gene transcript levels. PMID:19270134

Simplified MPN method for enumeration of soil naphthalene degraders using gaseous substrate.

PubMed

Wallenius, Kaisa; Lappi, Kaisa; Mikkonen, Anu; Wickström, Annika; Vaalama, Anu; Lehtinen, Taru; Suominen, Leena

2012-02-01

We describe a simplified microplate most-probable-number (MPN) procedure to quantify the bacterial naphthalene degrader population in soil samples. In this method, the sole substrate naphthalene is dosed passively via gaseous phase to liquid medium and the detection of growth is based on the automated measurement of turbidity using an absorbance reader. The performance of the new method was evaluated by comparison with a recently introduced method in which the substrate is dissolved in inert silicone oil and added individually to each well, and the results are scored visually using a respiration indicator dye. Oil-contaminated industrial soil showed slightly but significantly higher MPN estimate with our method than with the reference method. This suggests that gaseous naphthalene was dissolved in an adequate concentration to support the growth of naphthalene degraders without being too toxic. The dosing of substrate via gaseous phase notably reduced the work load and risk of contamination. The result scoring by absorbance measurement was objective and more reliable than measurement with indicator dye, and it also enabled further analysis of cultures. Several bacterial genera were identified by cloning and sequencing of 16S rRNA genes from the MPN wells incubated in the presence of gaseous naphthalene. In addition, the applicability of the simplified MPN method was demonstrated by a significant positive correlation between the level of oil contamination and the number of naphthalene degraders detected in soil.

Isolation and characterization of Pseudomonas aeruginosa strain SJTD-2 for degrading long-chain n-alkanes and crude oil.

PubMed

Xu, Jing; Liu, Huan; Liu, Jianhua; Liang, Rubing

2015-06-04

Oil pollution poses a severe threat to ecosystems, and bioremediation is considered as a safe and efficient alternative to physicochemical. for eliminating this contaminant. In this study, a gram-negative bacteria strain SJTD-2 isolated from oil-contaminated soil was found capable of utilizing n-alkanes and crude oil as sole energy sources. The efficiency of this strain in degrading these pollutants was analyzed. Strain SJTD-2 was identified on the basis of its phenotype, its physiological features, and a comparative genetic analysis using 16S rRNA sequence. Growth of strain SJTD-2 with different carbon sources (n-alkanes of different lengths and crude oil) was assessed, and the gas chromatography-mass spectrometry method was used to analyze the degradation efficiency of strain SJTD-2 for n-alkanes and petroleum by detecting the residual n-alkane concentrations. Strain SJTD-2 was identified as Pseudomonas aeruginosa based on the phenotype, physiological features, and 16S rRNA sequence analysis. This strain can efficiently decompose medium-chain and long-chain n-alkanes (C10-C26), and petroleum as its sole carbon sources. It preferred the long-chain n-alkanes (C18-C22), and n-docosane was considered as the best carbon source for its growth. In 48 h, 500 mg/L n-docosane could be degraded completely, and 2 g/L n-docosane was decomposed to undetectable levels within 72 h. Moreover, strain SJTD-2 could utilize about 88% of 2 g/L crude oil in 7days. Compared with other alkane-utilizing strains, strain SJTD-2 showed outstanding degradation efficiency for long-chain n-alkanes and high tolerance to petroleum at elevated concentrations. The isolation and characterization of strain SJTD-2 would help researchers study the mechanisms underlying the biodegradation of n-alkanes, and this strain could be used as a potential strain for environmental governance and soil bioremediation.

NUCLEOTIDE SEQUENCING AND TRANSCRIPTIONAL MAPPING OF THE GENES ENCODING BIPHENYL DIOXYGENASE, A MULTICOM- PONENT POLYCHLORINATED-BIPHENYL-DEGRADING ENZYME IN PSEUDOMONAS STRAIN LB400

EPA Science Inventory

The DNA region encoding biphenyl dioxygenase, the first enzyme in the biphenyl-polychlorinated biphenyl degradation pathway of Pseudomonas species strain LB400, was sequenced. Six open reading frames were identified, four of which are homologous to the components of toluene dioxy...

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

Isolation and characterization of novel strains of Pseudomonas aeruginosa and Serratia marcescens possessing high efficiency to degrade gasoline, kerosene, diesel oil, and lubricating oil.

PubMed

Wongsa, Patcharaporn; Tanaka, Makiko; Ueno, Akio; Hasanuzzaman, Mohammad; Yumoto, Isao; Okuyama, Hidetoshi

2004-12-01

Bacteria possessing high capacity to degrade gasoline, kerosene, diesel oil, and lubricating oil were screened from several areas of Hokkaido, Japan. Among isolates, two strains, WatG and HokM, which were identified as new strains of Pseudomonas aeruginosa and Serratia marcescens species, respectively, showed relatively high capacity and wide spectrum to degrade the hydrocarbons in gasoline, kerosene, diesel, and lubricating oil. About 90-95% of excess amount of total diesel oil and kerosene added to mineral salts media as a sole carbon source could be degraded by WatG within 2 and 3 weeks, respectively. The same amount of lubricating oil was 60% degraded within 2 weeks. Strain HokM was more capable than WatG in degrading aromatic compounds in gasoline. This strain could also degrade kerosene, diesel, and lubricating oil with a capacity of 50-60%. Thus, these two isolates have potential to be useful for bioremediation of sites highly contaminated with petroleum hydrocarbons.

Stable-Isotope Probing of Bacteria Capable of Degrading Salicylate, Naphthalene, or Phenanthrene in a Bioreactor Treating Contaminated Soil

PubMed Central

Singleton, David R.; Powell, Sabrina N.; Sangaiah, Ramiah; Gold, Avram; Ball, Louise M.; Aitken, Michael D.

2005-01-01

[13C6]salicylate, [U-13C]naphthalene, and [U-13C]phenanthrene were synthesized and separately added to slurry from a bench-scale, aerobic bioreactor used to treat soil contaminated with polycyclic aromatic hydrocarbons. Incubations were performed for either 2 days (salicylate, naphthalene) or 7 days (naphthalene, phenanthrene). Total DNA was extracted from the incubations, the “heavy” and “light” DNA were separated, and the bacterial populations associated with the heavy fractions were examined by denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone libraries. Unlabeled DNA from Escherichia coli K-12 was added to each sample as an internal indicator of separation efficiency. While E. coli was not detected in most analyses of heavy DNA, a low number of E. coli sequences was recovered in the clone libraries associated with the heavy DNA fraction of [13C]phenanthrene incubations. The number of E. coli clones recovered proved useful in determining the relative amount of light DNA contamination of the heavy fraction in that sample. Salicylate- and naphthalene-degrading communities displayed similar DGGE profiles and their clone libraries were composed primarily of sequences belonging to the Pseudomonas and Ralstonia genera. In contrast, heavy DNA from the phenanthrene incubations displayed a markedly different DGGE profile and was composed primarily of sequences related to the Acidovorax genus. There was little difference in the DGGE profiles and types of sequences recovered from 2- and 7-day incubations with naphthalene, so secondary utilization of the 13C during the incubation did not appear to be an issue in this experiment. PMID:15746319

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.

Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

PubMed Central

Khanolkar, Dnyanada S.; Naik, Milind Mohan; Dubey, Santosh Kumar

2014-01-01

A bacterial isolate capable of utilizing tributyltin chloride (TBTCl) as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME) analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM). Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed biotransformation of TBTCl into Dibutyltin dichloride (DBTCl2) through debutylation process. Therefore, Pseudomonas stutzeri strain DN2 may be used as a potential bacterial strain for bioremediation of TBTCl contaminated aquatic environmental sites. PMID:25763027

Bacterial chemotaxis along vapor-phase gradients of naphthalene.

PubMed

Hanzel, Joanna; Harms, Hauke; Wick, Lukas Y

2010-12-15

The role of bacterial growth and translocation for the bioremediation of organic contaminants in the vadose zone is poorly understood. Whereas air-filled pores restrict the mobility of bacteria, diffusion of volatile organic compounds in air is more efficient than in water. Past research, however, has focused on chemotactic swimming of bacteria along gradients of water-dissolved chemicals. In this study we tested if and to what extent Pseudomonas putida PpG7 (NAH7) chemotactically reacts to vapor-phase gradients forming above their swimming medium by the volatilization from a spot source of solid naphthalene. The development of an aqueous naphthalene gradient by air-water partitioning was largely suppressed by means of activated carbon in the agar. Surprisingly, strain PpG7 was repelled by vapor-phase naphthalene although the steady state gaseous concentrations were 50-100 times lower than the aqueous concentrations that result in positive chemotaxis of the same strain. It is thus assumed that the efficient gas-phase diffusion resulting in a steady, and possibly toxic, naphthalene flux to the cells controlled the chemotactic reaction rather than the concentration to which the cells were exposed. To our knowledge this is the first demonstration of apparent chemotactic behavior of bacteria in response to vapor-phase effector gradients.

Chemotaxis and degradation of organophosphate compound by a novel moderately thermo-halo tolerant Pseudomonas sp. strain BUR11: evidence for possible existence of two pathways for degradation.

PubMed

Pailan, Santanu; Saha, Pradipta

2015-01-01

An organophosphate (OP) degrading chemotactic bacterial strain BUR11 isolated from an agricultural field was identified as a member of Pseudomonas genus on the basis of its 16S rRNA gene sequence. The strain could utilize parathion, chlorpyrifos and their major hydrolytic intermediates as sole source of carbon for its growth and exhibited positive chemotactic response towards most of them. Optimum concentration of parathion for its growth was recorded to be 200 ppm and 62% of which was degraded within 96 h at 37 °C. Growth studies indicated the strain to be moderately thermo-halo tolerant in nature. Investigation based on identification of intermediates of parathion degradation by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC) and liquid chromatography mass spectrometry (LC-MS/MS) provided evidence for possible existence of two pathways. The first pathway proceeds via 4-nitrophenol (4-NP) while the second proceeds through formation of 4-aminoparathion (4-APar), 4-aminophenol (4-AP) and parabenzoquinone (PBQ). This is the first report of chemotaxis towards organophosphate compound by a thermo-halo tolerant bacterium.

Chemotaxis and degradation of organophosphate compound by a novel moderately thermo-halo tolerant Pseudomonas sp. strain BUR11: evidence for possible existence of two pathways for degradation

PubMed Central

Pailan, Santanu

2015-01-01

An organophosphate (OP) degrading chemotactic bacterial strain BUR11 isolated from an agricultural field was identified as a member of Pseudomonas genus on the basis of its 16S rRNA gene sequence. The strain could utilize parathion, chlorpyrifos and their major hydrolytic intermediates as sole source of carbon for its growth and exhibited positive chemotactic response towards most of them. Optimum concentration of parathion for its growth was recorded to be 200 ppm and 62% of which was degraded within 96 h at 37 °C. Growth studies indicated the strain to be moderately thermo-halo tolerant in nature. Investigation based on identification of intermediates of parathion degradation by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC) and liquid chromatography mass spectrometry (LC-MS/MS) provided evidence for possible existence of two pathways. The first pathway proceeds via 4-nitrophenol (4-NP) while the second proceeds through formation of 4-aminoparathion (4-APar), 4-aminophenol (4-AP) and parabenzoquinone (PBQ). This is the first report of chemotaxis towards organophosphate compound by a thermo-halo tolerant bacterium. PMID:26587344

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.

Degradation of trichloroethylene by Pseudomonas cepacia G4 and the constitutive mutant strain G4 5223 PR1 in aquifer microcosms

USGS Publications Warehouse

Krumme, M.L.; Timmis, K.N.; Dwyer, D.F.

1993-01-01

Pseudomonas cepacia G4 degrades trichloroethylene (TCE) via a degradation pathway for aromatic compounds which is induced by substrates such as phenol and tryptophan. P. cepacia G4 5223 PR1 (PR1) is a Tn5 insertion mutant which constitutively expresses the toluene ortho-monooxygenase responsible for TCE degradation. In groundwater microcosms, phenol-induced strain G4 and noninduced strain PR1 degraded TCE (20 and 50 microM) to nondetectable levels (< 0.1 microM) within 24 h at densities of 10(8) cells per ml; at lower densities, degradation of TCE was not observed after 48 h. In aquifer sediment microcosms, TCE was reduced from 60 to < 0.1 microM within 24 h at 5 x 10(8) PR1 organisms per g (wet weight) of sediment and from 60 to 26 microM over a period of 10 weeks at 5 x 10(7) PR1 organisms per g. Viable G4 and PR1 cells decreased from approximately 10(7) to 10(4) per g over the 10-week period.

Enhanced degradation of perfluorooctanoic acid by a genome shuffling-modified Pseudomonas parafulva YAB-1.

PubMed

Yi, Langbo; Peng, Qingzhong; Liu, Deming; Zhou, Lulu; Tang, Chongjian; Zhou, Yaoyu; Chai, Liyuan

2018-05-02

Perfluorooctanoic acid (PFOA) as an emerging persistent organic pollutant is hard to be degraded by conventional methods because of its stable physical and chemical properties. Microbial transformation is an attractive remediation approach to prevent and clean up PFOA contamination. To date, several strains of wild microbes have been reported to have limited capacity to degrade PFOA, selection of superior strains degrading PFOA become urgently necessary. Here, we report the application of genome shuffling to improve the PFOA-degrading bacterium Pseudomonas Parafulva YAB-1. The initial mutant populations of strain YAB1 were generated by nitrosoguanidine and ultraviolet irradiation mutagenesis respectively, resulting in mutants YM-9 and YM-19 with slightly improved PFOA-degrading ability. YM-9 and YM-19 were used as the starting strains for three rounds of recursive protoplast fusion. The positive mutants were screened on inorganic salt medium plates containing different concentrations of PFOA and selected based on their PFOA degradability in shake-flask fermentation test. The best performing recombinant F3-52 was isolated after three rounds of genome shuffling. In batch fermentation, the PFOA degradation rate of mutant F3-52 was up to 58.6%, which was 1.8-fold higher than that of the parent strain YAB1, and 1.6-fold higher than the initial mutants YM-9 and YM-19. Pass-generation test indicated that the heredity character of F3-52 was stable. The results demonstrated that genome shuffling was an efficient method for improving PFOA degradation of Pseudomonas Parafulva YAB1. The bred mutant F3-52 with 58.6% PFOA-degrading rate could be used for the environmental control of PFOA pollutant.

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

Oxidation of Naphthenoaromatic and Methyl-Substituted Aromatic Compounds by Naphthalene 1,2-Dioxygenase

PubMed Central

Selifonov, S. A.; Grifoll, M.; Eaton, R. W.; Chapman, P. J.

1996-01-01

Oxidation of acenaphthene, acenaphthylene, and fluorene was examined with recombinant strain Pseudomonas aeruginosa PAO1(pRE695) expressing naphthalene dioxygenase genes cloned from plasmid NAH7. Acenaphthene underwent monooxygenation to 1-acenaphthenol with subsequent conversion to 1-acenaphthenone and cis- and trans-acenaphthene-1,2-diols, while acenaphthylene was dioxygenated to give cis-acenaphthene-1,2-diol. Nonspecific dehydrogenase activities present in the host strain led to the conversion of both of the acenaphthene-1,2-diols to 1,2-acenaphthoquinone. The latter was oxidized spontaneously to naphthalene-1,8-dicarboxylic acid. No aromatic ring dioxygenation products were detected from acenaphthene and acenaphthylene. Mixed monooxygenase and dioxygenase actions of naphthalene dioxygenase on fluorene yielded products of benzylic 9-monooxygenation, aromatic ring dioxygenation, or both. The action of naphthalene dioxygenase on a variety of methyl-substituted aromatic compounds, including 1,2,4-trimethylbenzene and isomers of dimethylnaphthalene, resulted in the formation of benzylic alcohols, i.e., methyl group monooxygenation products, which were subsequently converted to the corresponding carboxylic acids by dehydrogenase(s) in the host strain. Benzylic monooxygenation of methyl groups was strongly predominant over aromatic ring dioxygenation and essentially nonspecific with respect to the substitution pattern of the aromatic substrates. In addition to monooxygenating benzylic methyl and methylene groups, naphthalene dioxygenase behaved as a sulfoxygenase, catalyzing monooxygenation of the sulfur heteroatom of 3-methylbenzothiophene. PMID:16535238

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.

Paracetamol - toxicity and microbial utilization. Pseudomonas moorei KB4 as a case study for exploring degradation pathway.

PubMed

Żur, Joanna; Wojcieszyńska, Danuta; Hupert-Kocurek, Katarzyna; Marchlewicz, Ariel; Guzik, Urszula

2018-09-01

Paracetamol, a widely used analgesic and antipyretic drug, is currently one of the most emerging pollutants worldwide. Besides its wide prevalence in the literature only several bacterial strains able to degrade this compound have been described. In this study, we isolated six new bacterial strains able to remove paracetamol. The isolated strains were identified as the members of Pseudomonas, Bacillus, Acinetobacter and Sphingomonas genera and characterized phenotypically and biochemically using standard methods. From the isolated strains, Pseudomonas moorei KB4 was able to utilize 50 mg L -1 of paracetamol. As the main degradation products, p-aminophenol and hydroquinone were identified. Based on the measurements of specific activity of acyl amidohydrolase, deaminase and hydroquinone 1,2-dioxygenase and the results of liquid chromatography analyses, we proposed a mechanism of paracetamol degradation by KB4 strain under co-metabolic conditions with glucose. Additionally, toxicity bioassays and the influence of various environmental factors, including pH, temperature, heavy metals at no-observed-effective-concentrations, and the presence of aromatic compounds on the efficiency and mechanism of paracetamol degradation by KB4 strain were determined. This comprehensive study about paracetamol biodegradation will be helpful in designing a treatment systems of wastewaters contaminated with paracetamol. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

Degradation of phenanthrene by Burkholderia sp. C3: initial 1,2- and 3,4-dioxygenation and meta- and ortho-cleavage of naphthalene-1,2-diol.

PubMed

Seo, Jong-Su; Keum, Young-Soo; Hu, Yuting; Lee, Sung-Eun; Li, Qing X

2007-02-01

Burkholderia sp. C3 was isolated from a polycyclic aromatic hydrocarbon (PAH)-contaminated site in Hilo, Hawaii, USA, and studied for its degradation of phenanthrene as a sole carbon source. The initial 3,4-C dioxygenation was faster than 1,2-C dioxygenation in the first 3-day culture. However, 1-hydroxy-2-naphthoic acid derived from 3,4-C dioxygenation degraded much slower than 2-hydroxy-1-naphthoic acid derived from 1,2-C dioxygenation. Slow degradation of 1-hydroxy-2-naphthoic acid relative to 2-hydroxy-1-naphthoic acid may trigger 1,2-C dioxygenation faster after 3 days of culture. High concentrations of 5,6- and 7,8-benzocoumarins indicated that meta-cleavage was the major degradation mechanism of phenanthrene-1,2- and -3,4-diols. Separate cultures with 2-hydroxy-1-naphthoic acid and 1-hydroxy-2-naphthoic acid showed that the degradation rate of the former to naphthalene-1,2-diol was much faster than that of the latter. The two upper metabolic pathways of phenanthrene are converged into naphthalene-1,2-diol that is further metabolized to 2-carboxycinnamic acid and 2-hydroxybenzalpyruvic acid by ortho- and meta-cleavages, respectively. Transformation of naphthalene-1,2-diol to 2-carboxycinnamic acid by this strain represents the first observation of ortho-cleavage of two rings-PAH-diols by a Gram-negative species.

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

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.

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

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

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

Detection and Characterization of Conjugative Degradative Plasmids in Xenobiotic-Degrading Sphingomonas Strains

PubMed Central

Basta, Tamara; Keck, Andreas; Klein, Joachim; Stolz, Andreas

2004-01-01

A systematic survey for the presence of plasmids in 17 different xenobiotic-degrading Sphingomonas strains was performed. In almost all analyzed strains, two to five plasmids with sizes of about 50 to 500 kb were detected by using pulsed-field gel electrophoresis. A comparison of plasmid preparations untreated or treated with S1 nuclease suggested that, in general, Sphingomonas plasmids are circular. Hybridization experiments with labeled gene probes suggested that large plasmids are involved in the degradation of dibenzo-p-dioxin, dibenzofuran, and naphthalenesulfonates in S. wittichii RW1, Sphingomonas sp. HH69, and S. xenophaga BN6, respectively. The plasmids which are responsible for the degradation of naphthalene, biphenyl, and toluene by S. aromaticivorans F199 (pNL1) and of naphthalenesulfonates by S. xenophaga BN6 (pBN6) were site-specifically labeled with a kanamycin resistance cassette. The conjugative transfer of these labeled plasmids was attempted with various bacterial strains as putative recipient strains. Thus, a conjugative transfer of plasmid pBN6 from S. xenophaga BN6 to a cured mutant of strain BN6 and to Sphingomonas sp. SS3 was observed. The conjugation experiments with plasmid pNL1 suggested a broader host range of this plasmid, because it was transferred without any obvious structural changes to S. yanoikuyae B1, Sphingomonas sp. SS3, and S. herbicidovorans. In contrast, major plasmid rearrangements were observed in the transconjugants after the transfer of plasmid pNL1 to Sphingomonas sp. HH69 and of pBN6 to Sphingomonas sp. SS3. No indications for the transfer of a Sphingomonas plasmid to bacteria outside of the Sphingomonadaceae were obtained. PMID:15175300

Reconstruction of a Nearly Complete Pseudomonas Draft Genome Sequence from a Coalbed Methane-Produced Water Metagenome

DOE PAGES

Ross, Daniel E.; Gulliver, Djuna

2016-10-06

The draft genome sequence ofPseudomonas stutzeristrain K35 was separated from a metagenome derived from a produced water microbial community of a coalbed methane well. The genome encodes a complete nitrogen fixation pathway and the upper and lower naphthalene degradation pathways.

Reconstruction of a Nearly Complete Pseudomonas Draft Genome Sequence from a Coalbed Methane-Produced Water Metagenome

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

Ross, Daniel E.; Gulliver, Djuna

The draft genome sequence ofPseudomonas stutzeristrain K35 was separated from a metagenome derived from a produced water microbial community of a coalbed methane well. The genome encodes a complete nitrogen fixation pathway and the upper and lower naphthalene degradation pathways.

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.

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.

Biodegradation of Mixed PAHs by PAH-Degrading Endophytic Bacteria.

PubMed

Zhu, Xuezhu; Ni, Xue; Waigi, Michael Gatheru; Liu, Juan; Sun, Kai; Gao, Yanzheng

2016-08-09

Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs) in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P₁ (Stenotrophomonas sp.) and P₃ (Pseudomonas sp.), which degraded more than 90% of phenanthrene (PHE) within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP), PHE, fluorene (FLR), pyrene (PYR), and benzo(a)pyrene (B(a)P) as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P₁ degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(a)P, and strain P₃ degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(a)P. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days). Compared with strain P₁, strain P₃ has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.

Kinetics of chromate reduction during naphthalene degradation in a mixed culture

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

Shen, H.; Sewell, G.W.; Pritchard, P.H.

A mixed culture of Bacillus sp. K1 and Sphingomonas paucimobilis EPA 505 was exposed to chromate and naphthalene. Batch experiments showed that chromate was reduced and naphthalene was degraded by the mixed culture. Chromate reduction occurred initially at a high rate followed by a decrease in rate until chromate reduction ceased. Chromate reduction decreased in the mixed culture when a lower ratio of S. paucimobilis EPA 505 to Bacillus sp. K1 was utilized. A kinetic model incorporating a term for the cell density ratio is proposed to describe chromate reduction in the mixed culture under both chromate limited and electronmore » donor limited conditions. The validity of the model, and its parameter values, was verified by experimental data generated under a variety of initial population compositions and a broad range of chromate concentrations. The consistent result of experimental data with model predictions implies that the model is useful for evaluating the interactions and the use of mixed culture for chromate removal.« less

Horizontal Transfer of phnAc Dioxygenase Genes within One of Two Phenotypically and Genotypically Distinctive Naphthalene-Degrading Guilds from Adjacent Soil Environments

PubMed Central

Wilson, Mark S.; Herrick, James B.; Jeon, Che Ok; Hinman, David E.; Madsen, Eugene L.

2003-01-01

Several distinct naphthalene dioxygenases have been characterized to date, which provides the opportunity to investigate the ecological significance, relative distribution, and transmission modes of the different analogs. In this study, we showed that a group of naphthalene-degrading isolates from a polycyclic aromatic hydrocarbon (PAH)-contaminated hillside soil were phenotypically and genotypically distinct from naphthalene-degrading organisms isolated from adjacent, more highly contaminated seep sediments. Mineralization of 14C-labeled naphthalene by soil slurries suggested that the in situ seep community was more acclimated to PAHs than was the in situ hillside community. phnAc-like genes were present in diverse naphthalene-degrading isolates cultured from the hillside soil, while nahAc-like genes were found only among isolates cultured from the seep sediments. The presence of a highly conserved nahAc allele among gram-negative isolates from the coal tar-contaminated seep area provided evidence for in situ horizontal gene transfer and was reported previously (J. B. Herrick, K. G. Stuart-Keil, W. C. Ghiorse, and E. L. Madsen, Appl. Environ. Microbiol. 63:2330-2337, 1997). Natural horizontal transfer of the phnAc sequence was also suggested by a comparison of the phnAc and 16S ribosomal DNA sequences of the hillside isolates. Analysis of metabolites produced by cell suspensions and patterns of amplicons produced by PCR analysis suggested both genetic and metabolic diversity among the naphthalene-degrading isolates of the contaminated hillside. These results provide new insights into the distribution, diversity, and transfer of phnAc alleles and increase our understanding of the acclimation of microbial communities to pollutants. PMID:12676698

Genome features of Pseudomonas putida LS46, a novel polyhydroxyalkanoate producer and its comparison with other P. putida strains

PubMed Central

2014-01-01

A novel strain of Pseudomonas putida LS46 was isolated from wastewater on the basis of its ability to synthesize medium chain-length polyhydroxyalkanoates (mcl-PHAs). P.putida LS46 was differentiated from other P.putida strains on the basis of cpn60 (UT). The complete genome of P.putida LS46 was sequenced and annotated. Its chromosome is 5,86,2556 bp in size with GC ratio of 61.69. It is encoding 5316 genes, including 7 rRNA genes and 76 tRNA genes. Nucleotide sequence data of the complete P. putida LS46 genome was compared with nine other P. putida strains (KT2440, F1, BIRD-1, S16, ND6, DOT-T1E, UW4, W619 and GB-1) identified either as biocontrol agents or as bioremediation agents and isolated from different geographical region and different environment. BLASTn analysis of whole genome sequences of the ten P. putida strains revealed nucleotide sequence identities of 86.54 to 97.52%. P.putida genome arrangement was LS46 highly similar to P.putida BIRD1 and P.putida ND6 but was markedly different than P.putida DOT-T1E, P.putida UW4 and P.putida W619. Fatty acid biosynthesis (fab), fatty acid degradation (fad) and PHA synthesis genes were highly conserved among biocontrol and bioremediation P.putida strains. Six genes in pha operon of P. putida LS46 showed >98% homology at gene and proteins level. It appears that polyhydroxyalkanoate (PHA) synthesis is an intrinsic property of P. putida and was not affected by its geographic origin. However, all strains, including P. putida LS46, were different from one another on the basis of house keeping genes, and presence of plasmid, prophages, insertion sequence elements and genomic islands. While P. putida LS46 was not selected for plant growth promotion or bioremediation capacity, its genome also encoded genes for root colonization, pyoverdine synthesis, oxidative stress (present in other soil isolates), degradation of aromatic compounds, heavy metal resistance and nicotinic acid degradation, manganese (Mn II) oxidation

New naphthalene whole-cell bioreporter for measuring and assessing naphthalene in polycyclic aromatic hydrocarbons contaminated site.

PubMed

Sun, Yujiao; Zhao, Xiaohui; Zhang, Dayi; Ding, Aizhong; Chen, Cheng; Huang, Wei E; Zhang, Huichun

2017-11-01

A new naphthalene bioreporter was designed and constructed in this work. A new vector, pWH1274_Nah, was constructed by the Gibson isothermal assembly fused with a 9 kb naphthalene-degrading gene nahAD (nahAa nahAb nahAc nahAd nahB nahF nahC nahQ nahE nahD) and cloned into Acinetobacter ADPWH_lux as the host, capable of responding to salicylate (the central metabolite of naphthalene). The ADPWH_Nah bioreporter could effectively metabolize naphthalene and evaluate the naphthalene in natural water and soil samples. This whole-cell bioreporter did not respond to other polycyclic aromatic hydrocarbons (PAHs; pyrene, anthracene, and phenanthrene) and demonstrated a positive response in the presence of 0.01 μM naphthalene, showing high specificity and sensitivity. The bioluminescent response was quantitatively measured after a 4 h exposure to naphthalene, and the model simulation further proved the naphthalene metabolism dynamics and the salicylate-activation mechanisms. The ADPWH_Nah bioreporter also achieved a rapid evaluation of the naphthalene in the PAH-contaminated site after chemical spill accidents, showing high consistency with chemical analysis. The engineered Acinetobacter variant had significant advantages in rapid naphthalene detection in the laboratory and potential in situ detection. The state-of-the-art concept of cloning PAHs-degrading pathway in salicylate bioreporter hosts led to the construction and assembly of high-throughput PAH bioreporter array, capable of crude oil contamination assessment and risk management. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioremediation of p-Nitrophenol by Pseudomonas putida 1274 strain

PubMed Central

2014-01-01

Background p-Nitrophenol (PNP) occurs as contaminants of industrial effluents and it is the most important environmental pollutant and causes significant health and environmental risks, because it is toxic to many living organisms. Nevertheless, the information regarding PNP degradation pathways and their enzymes remain limited. Objective To evaluate the efficacy of the Pseudomonas Putida 1274 for removal of PNP. Methods P. putida MTCC 1274 was obtained from MTCC Chandigarh, India and cultured in the minimal medium in the presence of PNP. PNP degradation efficiency was compared under different pH and temperature ranges. The degraded product was isolated and analyzed with different chromatographic and spectroscopic techniques. Results P. putida 1274 shows good growth and PNP degradation at 37°C in neutral pH. Acidic and alkali pH retarded the growth of P. putida as well as the PNP degradation. On the basis of specialized techniques, hydroquinone was identified as major degraded product. The pathway was identified for the biodegradation of PNP. It involved initial removal of the nitrate group and formation of hydroquinone as one of the intermediates. Conclusion Our results suggested that P. putida 1274 strain would be a suitable aspirant for bioremediation of nitro-aromatic compounds contaminated sites in the environment. PMID:24581307

Cometabolic Degradation of Naproxen by Planococcus sp. Strain S5.

PubMed

Domaradzka, Dorota; Guzik, Urszula; Hupert-Kocurek, Katarzyna; Wojcieszyńska, Danuta

Naproxen is a non-steroidal anti-inflammatory drug frequently detected in the influent and effluent of sewage treatment plants. The Gram-positive strain Planococcus sp. S5 was able to remove approximately 30 % of naproxen after 35 days of incubation in monosubstrate culture. Under cometabolic conditions, with glucose or phenol as a growth substrate, the degradation efficiency of S5 increased. During 35 days of incubation, 75.14 ± 1.71 % and 86.27 ± 2.09 % of naproxen was degraded in the presence of glucose and phenol, respectively. The highest rate of naproxen degradation observed in the presence of phenol may be connected with the fact that phenol is known to induce enzymes responsible for aromatic ring cleavage. The activity of phenol monooxygenase, naphthalene monooxygenase, and hydroxyquinol 1,2-dioxygenase was indicated in Planococcus sp. S5 culture with glucose or phenol as a growth substrate. It is suggested that these enzymes may be engaged in naproxen degradation.

Actions of a versatile fluorene-degrading bacterial isolate on polycyclic aromatic compounds.

PubMed Central

Grifoll, M; Selifonov, S A; Gatlin, C V; Chapman, P J

1995-01-01

Pseudomonas cepacia F297 grew with fluorene as a sole source of carbon and energy; its growth yield corresponded to an assimilation of about 40% of fluorene carbon. The accumulation of a ring meta-cleavage product during growth and the identification of 1-indanone in growth media and washed-cell suspensions suggest that strain F297 metabolizes fluorene by mechanisms analogous to those of naphthalene degradation. In addition to fluorene, strain F297 utilized for growth a wide variety of polycyclic aromatic compounds (PACs), including naphthalene, 2,3-dimethylnaphthalene, phenanthrene, anthracene, and dibenzothiophene. Fluorene-induced cells of the strain also transformed 2,6-dimethylnaphthalene, biphenyl, dibenzofuran, acenaphthene, and acenaphthylene. The identification of products formed from those substrates (by gas chromatography-mass spectrometry) in washed-cell suspensions indicates that P. cepacia F297 carries out the following reactions: (i) aromatic ring oxidation and cleavage, apparently using the pyruvate released for growth, (ii) methyl group oxidations, (iii) methylenic oxidations, and (iv) S oxidations of aromatic sulfur heterocycles. Strain F297 grew with a creosote-PAC mixture, producing an almost complete removal of all aromatic compounds containing 2 to 3 rings in 14 days, as demonstrated by gas chromatography analysis of the remaining PACs recovered from cultures. The identification of key chemicals confirmed that not only are certain compounds depleted but also the anticipated reaction products are found. PMID:7487007

Actions of a versatile fluorene-degrading bacterial isolate on polycyclic aromatic compounds.

PubMed

Grifoll, M; Selifonov, S A; Gatlin, C V; Chapman, P J

1995-10-01

Pseudomonas cepacia F297 grew with fluorene as a sole source of carbon and energy; its growth yield corresponded to an assimilation of about 40% of fluorene carbon. The accumulation of a ring meta-cleavage product during growth and the identification of 1-indanone in growth media and washed-cell suspensions suggest that strain F297 metabolizes fluorene by mechanisms analogous to those of naphthalene degradation. In addition to fluorene, strain F297 utilized for growth a wide variety of polycyclic aromatic compounds (PACs), including naphthalene, 2,3-dimethylnaphthalene, phenanthrene, anthracene, and dibenzothiophene. Fluorene-induced cells of the strain also transformed 2,6-dimethylnaphthalene, biphenyl, dibenzofuran, acenaphthene, and acenaphthylene. The identification of products formed from those substrates (by gas chromatography-mass spectrometry) in washed-cell suspensions indicates that P. cepacia F297 carries out the following reactions: (i) aromatic ring oxidation and cleavage, apparently using the pyruvate released for growth, (ii) methyl group oxidations, (iii) methylenic oxidations, and (iv) S oxidations of aromatic sulfur heterocycles. Strain F297 grew with a creosote-PAC mixture, producing an almost complete removal of all aromatic compounds containing 2 to 3 rings in 14 days, as demonstrated by gas chromatography analysis of the remaining PACs recovered from cultures. The identification of key chemicals confirmed that not only are certain compounds depleted but also the anticipated reaction products are found.

Biodegradation of propargite by Pseudomonas putida, isolated from tea rhizosphere.

PubMed

Sarkar, Soumik; Seenivasan, Subbiah; Asir, Robert Premkumar Samuel

2010-02-15

Biodegradation of miticide propargite was carried out in vitro by selected Pseudomonas strains isolated from tea rhizosphere. A total number of 13 strains were isolated and further screened based on their tolerance level to different concentrations of propargite. Five best strains were selected and further tested for their nutritional requirements. Among the different carbon sources tested glucose exhibited the highest growth promoting capacity and among nitrogen sources ammonium nitrate supported the growth to the maximum. The five selected Pseudomonas strain exhibited a range of degradation capabilities. Mineral salts medium (MSM) amended with glucose provided better environment for degradation with the highest degradation potential in strain SPR 13 followed by SPR 8 (71.9% and 69.0% respectively).

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.

Draft Genome Sequence of Pseudomonas pachastrellae Strain CCUG 46540T, a Deep-Sea Bacterium

PubMed Central

2017-01-01

ABSTRACT Pseudomonas pachastrellae strain CCUG 46540T (KMM 330T) was isolated from a deep-sea sponge specimen collected in the Philippine Sea at a depth of 750 m. The draft genome has an estimated size of 4.0 Mb, exhibits a G+C content of 61.2 mol%, and is predicted to encode 3,592 proteins, including pathways for the degradation of aromatic compounds. PMID:28385850

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 a novel Pseudomonas sp. that mineralizes high concentrations of pentachlorophenol.

PubMed Central

Radehaus, P M; Schmidt, S K

1992-01-01

A pentachlorophenol (PCP)-mineralizing bacterium was isolated from polluted soil and identified as Pseudomonas sp. strain RA2. In batch cultures, Pseudomonas sp. strain RA2 used PCP as its sole source of carbon and energy and was capable of completely degrading this compound as indicated by radiotracer studies, stoichiometric release of chloride, and biomass formation. Pseudomonas sp. strain RA2 was able to mineralize a higher concentration of PCP (160 mg liter-1) than any previously reported PCP-degrading pseudomonad. At a PCP concentration of 200 mg liter-1, cell growth was completely inhibited and PCP was not degraded, although an active population of Pseudomonas sp. RA2 was still present in these cultures after 2 weeks. The inhibitory effect of PCP was partially attributable to its effect on the growth rate of Pseudomonas sp. strain RA2. The highest specific growth rate (mu = 0.09 h-1) was reached at a PCP concentration of 40 mg liter-1 but decreased at higher or lower PCP concentrations, with the lowest mu (0.05 h-1) occurring at 150 mg liter-1. Despite this reduction in growth rate, total biomass production was proportional to PCP concentration at all PCP concentrations degraded by Pseudomonas sp. RA2. In contrast, final cell density was reduced to below expected values at PCP concentrations greater than 100 mg liter-1. These results indicate that, in addition to its effect as an uncoupler of oxidative phosphorylation, PCP may also inhibit cell division in Pseudomonas sp. strain RA2.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1444401

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

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...

Draft Genome Sequence of Pseudomonas pachastrellae Strain CCUG 46540T, a Deep-Sea Bacterium.

PubMed

Gomila, Margarita; Mulet, Magdalena; Lalucat, Jorge; García-Valdés, Elena

2017-04-06

Pseudomonas pachastrellae strain CCUG 46540 T (KMM 330 T ) was isolated from a deep-sea sponge specimen collected in the Philippine Sea at a depth of 750 m. The draft genome has an estimated size of 4.0 Mb, exhibits a G+C content of 61.2 mol%, and is predicted to encode 3,592 proteins, including pathways for the degradation of aromatic compounds. Copyright © 2017 Gomila et al.

Biodegradation Ability and Catabolic Genes of Petroleum-Degrading Sphingomonas koreensis Strain ASU-06 Isolated from Egyptian Oily Soil

PubMed Central

Mostafa, Yasser M.; Shoreit, Ahmed

2014-01-01

Polycyclic aromatic hydrocarbons (PAHs) are serious pollutants and health hazards. In this study, 15 PAHs-degrading bacteria were isolated from Egyptian oily soil. Among them, one Gram-negative strain (ASU-06) was selected and biodegradation ability and initial catabolic genes of petroleum compounds were investigated. Comparison of 16S rRNA gene sequence of strain ASU-06 to published sequences in GenBank database as well as phylogenetic analysis identified ASU-06 as Sphingomonas koreensis. Strain ASU-06 degraded 100, 99, 98, and 92.7% of 100 mg/L naphthalene, phenanthrene, anthracene, and pyrene within 15 days, respectively. When these PAHs present in a mixed form, the enhancement phenomenon appeared, particularly in the degradation of pyrene, whereas the degradation rate was 98.6% within the period. This is the first report showing the degradation of different PAHs by this species. PCR experiments with specific primers for catabolic genes alkB, alkB1, nahAc, C12O, and C23O suggested that ASU-06 might possess genes for aliphatic and PAHs degradation, while PAH-RHDαGP gene was not detected. Production of biosurfactants and increasing cell-surface hydrophobicity were investigated. GC/MS analysis of intermediate metabolites of studied PAHs concluded that this strain utilized these compounds via two main pathways, and phthalate was the major constant product that appeared in each day of the degradation period. PMID:25177681

Cyclodextrin-enhanced degradation of toluene and p-toluic acid by Pseudomonas putida.

PubMed Central

Schwartz, A; Bar, R

1995-01-01

Degradation of an immiscible aromatic solvent, toluene, and a water-soluble aromatic compound, p-toluic acid, by a Pseudomonas putida strain in the presence of beta-cyclodextrin (beta-CD) was investigated. The ability of CDs to interact with hydrophobic organics and form inclusion compounds was exploited in this study to remove or alleviate the toxicities of substrates and consequently to enable or enhance degradation. Liquid toluene was found to be highly toxic to P. putida. However, this phase toxicity was removed when crystalline beta-CD-complexed toluene was provided as the substrate. The latter was fully degraded at a concentration of up to 10 g/liter. Degradation of toluene vapors was enhanced in the presence of beta-CD as a result of reduced molecular toxicity and facilitated absorption of the gaseous substrate. Similarly, beta-CD alleviated the inhibitory effect of p-toluic acid on P. putida. This protective effect of CD was remarkably more prominent when the microbial culture was shock loaded with an otherwise toxic dose of p-toluic acid (1.8 g/liter). PMID:7618884

Hydrogen Isotope Fractionation As a Tool to Identify Aerobic and Anaerobic PAH Biodegradation.

PubMed

Kümmel, Steffen; Starke, Robert; Chen, Gao; Musat, Florin; Richnow, Hans H; Vogt, Carsten

2016-03-15

Aerobic and anaerobic polycyclic aromatic hydrocarbon (PAH) biodegradation was characterized by compound specific stable isotope analysis (CSIA) of the carbon and hydrogen isotope effects of the enzymatic reactions initiating specific degradation pathways, using naphthalene and 2-methylnaphtalene as model compounds. Aerobic activation of naphthalene and 2-methylnaphthalene by Pseudomonas putida NCIB 9816 and Pseudomonas fluorescens ATCC 17483 containing naphthalene dioxygenases was associated with moderate carbon isotope fractionation (εC = -0.8 ± 0.1‰ to -1.6 ± 0.2‰). In contrast, anaerobic activation of naphthalene by a carboxylation-like mechanism by strain NaphS6 was linked to negligible carbon isotope fractionation (εC = -0.2 ± 0.2‰ to -0.4 ± 0.3‰). Notably, anaerobic activation of naphthalene by strain NaphS6 exhibited a normal hydrogen isotope fractionation (εH = -11 ± 2‰ to -47 ± 4‰), whereas an inverse hydrogen isotope fractionation was observed for the aerobic strains (εH = +15 ± 2‰ to +71 ± 6‰). Additionally, isotope fractionation of NaphS6 was determined in an overlaying hydrophobic carrier phase, resulting in more reliable enrichment factors compared to immobilizing the PAHs on the bottle walls without carrier phase. The observed differences especially in hydrogen fractionation might be used to differentiate between aerobic and anaerobic naphthalene and 2-methylnaphthalene biodegradation pathways at PAH-contaminated field sites.

Degradation of Benzene by Pseudomonas veronii 1YdBTEX2 and 1YB2 Is Catalyzed by Enzymes Encoded in Distinct Catabolism Gene Clusters.

PubMed

de Lima-Morales, Daiana; Chaves-Moreno, Diego; Wos-Oxley, Melissa L; Jáuregui, Ruy; Vilchez-Vargas, Ramiro; Pieper, Dietmar H

2016-01-01

Pseudomonas veronii 1YdBTEX2, a benzene and toluene degrader, and Pseudomonas veronii 1YB2, a benzene degrader, have previously been shown to be key players in a benzene-contaminated site. These strains harbor unique catabolic pathways for the degradation of benzene comprising a gene cluster encoding an isopropylbenzene dioxygenase where genes encoding downstream enzymes were interrupted by stop codons. Extradiol dioxygenases were recruited from gene clusters comprising genes encoding a 2-hydroxymuconic semialdehyde dehydrogenase necessary for benzene degradation but typically absent from isopropylbenzene dioxygenase-encoding gene clusters. The benzene dihydrodiol dehydrogenase-encoding gene was not clustered with any other aromatic degradation genes, and the encoded protein was only distantly related to dehydrogenases of aromatic degradation pathways. The involvement of the different gene clusters in the degradation pathways was suggested by real-time quantitative reverse transcription PCR. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Mechanisms for naphthalene removal during electrolytic aeration.

PubMed

Goel, Ramesh K; Flora, Joseph R V; Ferry, John

2003-02-01

Batch tests were performed to investigate chemical and physical processes that may result during electrolytic aeration of a contaminated aquifer using naphthalene as a model contaminant. Naphthalene degradation of 58-66% took place electrolytically and occurred at the same rates at a pH of 4 and 7. 1,4-naphthoquinone was identified as a product of the electrolysis. Stripping due to gases produced at the electrodes did not result in any naphthalene loss. Hydrogen peroxide (which may be produced at the cathode) did not have any effect on naphthalene, but the addition of ferrous iron (which may be present in aquifers) resulted in 67-99% disappearance of naphthalene. Chlorine (which may be produced from the anodic oxidation of chloride) can effectively degrade naphthalene at pH of 4, but not at a pH of 7. Mono-, di- and poly chloronaphthalenes were identified as oxidation products. Ferric iron coagulation (due to the oxidation of ferrous iron) did not significantly contribute to naphthalene loss. Overall, electrolytic oxidation and chemical oxidation due to the electrolytic by-products formed are significant abiotic processes that could occur and should be accounted for if bioremediation of PAH-contaminated sites via electrolytic aeration is considered. Possible undesirable products such as chlorinated compounds may be formed when significant amounts of chlorides are present.

Prevalence and spread of pseudomonas aeruginosa and Klebsiella pneumoniae strains in patients with hematological malignancies.

PubMed

Kolar, Milan; Sauer, Pavel; Faber, Edgar; Kohoutova, Jarmila; Stosová, Tatana; Sedlackova, Michaela; Chroma, Magdalena; Koukalova, Dagmar; Indrak, Karel

2009-01-01

The aim of the study was to determine the prevalence of Pseudomonas aeruginosa and Klebsiella pneumoniae strains in patients with acute leukemias, to assess their clinical significance, and to define the sources and ways of their spread using genetic analysis. Thirty-four patients were investigated during the observed period. Twenty-one strains of Pseudomonas aeruginosa and 35 strains of Klebsiella pneumoniae were isolated from patient samples. In the case of Pseudomonas aeruginosa, 47.6% of strains were identified as pathogens and caused infection. By contrast, only 4 isolates (11.4%) of Klebsiella pneumoniae could be regarded as etiological agents of bacterial infection. Based on the obtained results, Klebsiella pneumoniae strains are assumed to be of mostly endogenous origin. In the case of Pseudomonas aeruginosa strains, the proportion of identical strains detected in various patients was higher and exogenous sources were more significant. In addition, our results confirmed the ability of Pseudomonas aeruginosa strains to survive on a particular site in the hospital for a longer time.

Biodegradation of naphthalene and phenanthren by Bacillus subtilis 3KP

NASA Astrophysics Data System (ADS)

Ni'matuzahroh, Trikurniadewi, N.; Pramadita, A. R. A.; Pratiwi, I. A.; Salamun, Fatimah, Sumarsih, Sri

2017-06-01

The purposes of this research were to know growth response, degradation ability, and uptake mechanism of naphthalene and phenanthrene by Bacillus subtilis 3KP. Bacillus subtilis 3KP was grown on Mineral Synthetic (MS) medium with addition of 1% yeast extract and naphthalene and phenanthrene respectively 200 ppm in different cultures. Bacillus subtilis 3KP growth response was monitored by Total Plate Count (TPC) method, the degradation ability was monitored by UV-Vis spectrophotometer, and the uptake mechanism of hydrocarbon was monitored by emulsification activity, decrease of surface tension, and activity of Bacterial Adherence to Hydrocarbon (BATH). Bacillus subtilis 3KP was able to grow and show biphasic growth pattern on both of substrates. Naphthalene and phenanthrene were used as a carbon source for Bacillus subtilis 3KP growth that indicated by the reduction of substrate concomitant with the growth. At room temperature conditions (± 30°C) and 90 rpm of agitation for 7 days, Bacillus subtilis 3KP could degrade naphthalene in the amount of 70.5% and phenanthrene in the amount of 24.8%. Based on the analysis of UV-Vis spectrophotometer, three metabolites, 1-hydroxy-2-naphthoic acid, salicylic acid, and pyrocatechol were found in both cultures. The metabolite identification became basis of propose degradation pathway of naphthalene and phenanthrene by Bacillus subtilis 3KP. The results of hydrocarbon uptake mechanism test show that Bacillus subtilis 3KP used all of the mechanism to degrade naphthalene and phenanthrene.

Pseudomonas diversity in crude-oil-contaminated intertidal sand samples obtained after the Prestige oil spill.

PubMed

Mulet, Magdalena; David, Zoyla; Nogales, Balbina; Bosch, Rafael; Lalucat, Jorge; García-Valdés, Elena

2011-02-01

The Galicia seashore, in northwestern Spain, was one of the shorelines affected by the Prestige oil spill in November 2002. The diversity of autochthonous Pseudomonas populations present at two beaches (Carnota municipality) was analyzed using culture-independent and culture-dependent methods. The first analysis involved the screening of an rpoD gene library. The second involved the isolation of 94 Pseudomonas strains that were able to grow on selective media by direct plating or after serial enrichments on several carbon sources: biphenyl, gentisate, hexadecane, methylnaphthalene, naphthalene, phenanthrene, salicylate, xylene, and succinate. Eight denitrifying Pseudomonas strains were also isolated by their ability to grow anaerobically with nitrate. The calculated coverage index for Pseudomonas species was 89% when clones and isolates were considered together, and there were 29 phylospecies detected. The most abundant were members of the species P. stutzeri, P. putida, P. anguilliseptica, and P. oleovorans. Thirty-one isolates could not be identified at the species level and were considered representatives of 16 putative novel Pseudomonas species. One isolate was considered representative of a novel P. stutzeri genomovar. Concordant results were obtained when the diversities of the cloned DNA library and the cultured strains were compared. The clone library obtained by the rpoD PCR method was a useful tool for evaluating Pseudomonas communities and also for microdiversity studies of Pseudomonas populations.

The T7-related Pseudomonas putida phage φ15 displays virion-associated biofilm degradation properties.

PubMed

Cornelissen, Anneleen; Ceyssens, Pieter-Jan; T'Syen, Jeroen; Van Praet, Helena; Noben, Jean-Paul; Shaburova, Olga V; Krylov, Victor N; Volckaert, Guido; Lavigne, Rob

2011-04-19

Formation of a protected biofilm environment is recognized as one of the major causes of the increasing antibiotic resistance development and emphasizes the need to develop alternative antibacterial strategies, like phage therapy. This study investigates the in vitro degradation of single-species Pseudomonas putida biofilms, PpG1 and RD5PR2, by the novel phage ϕ15, a 'T7-like virus' with a virion-associated exopolysaccharide (EPS) depolymerase. Phage ϕ15 forms plaques surrounded by growing opaque halo zones, indicative for EPS degradation, on seven out of 53 P. putida strains. The absence of haloes on infection resistant strains suggests that the EPS probably act as a primary bacterial receptor for phage infection. Independent of bacterial strain or biofilm age, a time and dose dependent response of ϕ15-mediated biofilm degradation was observed with generally a maximum biofilm degradation 8 h after addition of the higher phage doses (10(4) and 10(6) pfu) and resistance development after 24 h. Biofilm age, an in vivo very variable parameter, reduced markedly phage-mediated degradation of PpG1 biofilms, while degradation of RD5PR2 biofilms and ϕ15 amplification were unaffected. Killing of the planktonic culture occurred in parallel with but was always more pronounced than biofilm degradation, accentuating the need for evaluating phages for therapeutic purposes in biofilm conditions. EPS degrading activity of recombinantly expressed viral tail spike was confirmed by capsule staining. These data suggests that the addition of high initial titers of specifically selected phages with a proper EPS depolymerase are crucial criteria in the development of phage therapy.

[Isolation and Identification of Petroleum Degradation Bacteria and Interspecific Interactions Among Four Bacillus Strains].

PubMed

Wang, Jia-nan; Shi, Yan-yun; Zheng, Li-yan; Wang, Zhe; Cai, Zhang; Liu, Jie

2015-06-01

Six petroleum-degrading strains were isolated from oil-contaminated soil at Dagang oil field and oil sewage on Bohai offshore drilling platform in Tianjin using enrichment culture and isolation method. The physiological biochemical test together with 16S rDNA sequencing analysis indicated that they belonged to Bacillus (S1, S2, S3, S4), Pseudomonas (W1) and Ochrobactrum (W2), respectively. The strain S3 had the maximum degradation rate of alkane (41.3%) and aromatic hydrocarbon (30.9%) among all isolated strains showing the better degradation efficiency by endogenous bacteria when compared to that by the exogenous bacteria. The four Bacillus strains were used to construct microbiome, thereafter subjected to petroleum degradation efficiency test and analyzed. The results showed that microbiome F3 consisting of S1 and S4 had the maximum degradation rates of alkane (50.5%) and aromatic hydrocarbon (54.0%), which were 69.9% and 156.1% higher than those by single bacterium, respectively. Furthermore, they were 22.1% and 74.6% respectively higher than those by the most optimal degradation bacterium S3. Microbiome F4 consisting of S2 and S3 had the minimum degradation rates of alkane (18.5%) and aromatic hydrocarbon (18.9%) which were 55.3% and 39.0% lower than the degradation rates of single bacterium, respectively. The results also demonstrated that there were both microbial synergy promotion and antagonism inhibition among bacteria of the same genus in the petroleum degradation period. Bacteria with close affinity in Bacillus genus displayed mainly promoted petroleum degradation effect.

CHARACTERIZATION AND NUCLEOTIDE SEQUENCE DETERMINATION OF A REPEAT ELEMENT ISOLATED FROM A 2,4,5,-T DEGRADING STRAIN OF PSEUDOMONAS CEPACIA

EPA Science Inventory

Pseudomonas cepacia strain AC1100, capable of growth on 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), was mutated to the 2,4,5-T− strain PT88 by a ColE1 :: Tn5 chromosomal insertion. Using cloned DNA from the region flanking the insertion, a 1477-bp sequence (designated RS1100) wa...

Degradation of Triphenyltin by a Fluorescent Pseudomonad

PubMed Central

Inoue, Hiroyuki; Takimura, Osamu; Fuse, Hiroyuki; Murakami, Katsuji; Kamimura, Kazuo; Yamaoka, Yukiho

2000-01-01

Triphenyltin (TPT)-degrading bacteria were screened by a simple technique using a post-column high-performance liquid chromatography using 3,3′,4′,7-tetrahydroxyflavone as a post-column reagent for determination of TPT and its metabolite, diphenyltin (DPT). An isolated strain, strain CNR15, was identified as Pseudomonas chlororaphis on the basis of its morphological and biochemical features. The incubation of strain CNR15 in a medium containing glycerol, succinate, and 130 μM TPT resulted in the rapid degradation of TPT and the accumulation of approximately 40 μM DPT as the only metabolite after 48 h. The culture supernatants of strain CNR15, grown with or without TPT, exhibited a TPT degradation activity, whereas the resting cells were not capable of degrading TPT. TPT was stoichiometrically degraded to DPT by the solid-phase extract of the culture supernatant, and benzene was detected as another degradation product. We found that the TPT degradation was catalyzed by low-molecular-mass substances (approximately 1,000 Da) in the extract, termed the TPT-degrading factor. The other fluorescent pseudomonads, P. chlororaphis ATCC 9446, Pseudomonas fluorescens ATCC 13525, and Pseudomonas aeruginosa ATCC 15692, also showed TPT degradation activity similar to strain CNR15 in the solid-phase extracts of their culture supernatants. These results suggest that the extracellular low-molecular-mass substance that is universally produced by the fluorescent pseudomonad could function as a potent catalyst to cometabolite TPT in the environment. PMID:10919812

Pseudomonas fluorescens HK44: Lessons Learned from a Model Whole-Cell Bioreporter with a Broad Application History

PubMed Central

Trögl, Josef; Chauhan, Archana; Ripp, Steven; Layton, Alice C.; Kuncová, Gabriela; Sayler, Gary S.

2012-01-01

Initially described in 1990, Pseudomonas fluorescens HK44 served as the first whole-cell bioreporter genetically endowed with a bioluminescent (luxCDABE) phenotype directly linked to a catabolic (naphthalene degradative) pathway. HK44 was the first genetically engineered microorganism to be released in the field to monitor bioremediation potential. Subsequent to that release, strain HK44 had been introduced into other solids (soils, sands), liquid (water, wastewater), and volatile environments. In these matrices, it has functioned as one of the best characterized chemically-responsive environmental bioreporters and as a model organism for understanding bacterial colonization and transport, cell immobilization strategies, and the kinetics of cellular bioluminescent emission. This review summarizes the characteristics of P. fluorescens HK44 and the extensive range of its applications with special focus on the monitoring of bioremediation processes and biosensing of environmental pollution. PMID:22438725

Anaerobic oxidation of 2-chloroethanol under denitrifying conditions by Pseudomonas stutzeri strain JJ.

PubMed

Dijk, J A; Stams, A J M; Schraa, G; Ballerstedt, H; de Bont, J A M; Gerritse, J

2003-11-01

A bacterium that uses 2-chloroethanol as sole energy and carbon source coupled to denitrification was isolated from 1,2-dichloroethane-contaminated soil. Its 16 S rDNA sequence showed 98% similarity with the type strain of Pseudomonas stutzeri (DSM 5190) and the isolate was tentatively identified as Pseudomonas stutzeri strain JJ. Strain JJ oxidized 2-chloroethanol completely to CO(2) with NO(3)(- )or O(2) as electron acceptor, with a preference for O(2) if supplied in combination. Optimum growth on 2-chloroethanol with nitrate occurred at 30 degrees C with a mu(max) of 0.14 h(-1) and a yield of 4.4 g protein per mol 2-chloroethanol metabolized. Under aerobic conditions, the mu(max) was 0.31 h(-1). NO(2)(-) also served as electron acceptor, but reduction of Fe(OH)(3), MnO(2), SO(4)(2-), fumarate or ClO(3)(-) was not observed. Another chlorinated compound used as sole energy and carbon source under aerobic and denitrifying conditions was chloroacetate. Various different bacterial strains, including some closely related Pseudomonas stutzeri strains, were tested for their ability to grow on 2-chloroethanol as sole energy and carbon source under aerobic and denitrifying conditions, respectively. Only three strains, Pseudomonas stutzeri strain LMD 76.42, Pseudomonas putida US2 and Xanthobacter autotrophicus GJ10, grew aerobically on 2-chloroethanol. This is the first report of oxidation of 2-chloroethanol under denitrifying conditions by a pure bacterial culture.

[Fatty acids composition of cellular lipids of the collected and newly isolated Pseudomonas lupini strains].

PubMed

Hvozdiak, R I; Dankevych, L A; Votselko, S K; Holubets', O V

2005-01-01

Fatty acid composition of cellular lipids of 23 Pseudomonas lupini strains (Beltjukova et Koroljova 1968) has been investigated. Cellular fatty acids which contained from C10 to C19 carbon atoms have been identified. Basic fatty acid of those Pseudomonas cells are hexadecanoic, hexadecenoic and octadecanoic acids. The 3-hydroxydecanoic (C10:0 3OH), 3-hydroxydodecanoic (C12:0 3OH), 2-hydroxydodecanoic (C12:0 2OH) and cyclopropane fatty acids which contain 17 and 19 carbon atoms have been detected in cellular lipids. The cellular fatty acids spectra of 22 P. lupini strains are similar to cellular fatty acids spectrum of the type strain Pseudomonas syringae pv. syringae 8511. Pathogenic isolate 2, which fatty acid content of cell lipids significantly differ from lipids of cell fatty acids from P. lupini strains and cell lipids of fatty acids of typical strains Pseudomonas syringae pv. syringae 8511 and Pseudomonas savastanoi pv. phaseolicola 9066 is the exception.

Thalassospira permensis sp. nov., a new terrestrial halotolerant bacterium isolated from a naphthalene-utilizing microbial consortium.

PubMed

Plotnikova, E G; Anan'ina, L N; Krausova, V I; Ariskina, E V; Prisyazhnaya, N V; Lebedev, A T; Demakov, V A; Evtushenko, L I

2011-01-01

A halotolerant bacterium, strain SMB34T, was isolated from a naphthalene-utilizing bacterial consortium obtained from primitive technogeneous soil (Vrkhnekamsk salt deposit, Perm region, Russia) by enrichment procedure. The strain itself was unable to degrade naphthalene and grew at NaCl concentrations up to 11% (w/v). The 16S rRNA-based phylogenetic analysis showed that the strain belongs to the genus Thalassospira. The DNA-DNA hybridization values between SMB34T and the type strains of phylogenetically closest species (T. xiamenensis, T. profundimaris and T. tepidiphila) did not exceed 50%. The novel strain could be distinguished from the above species by the cell motility, MALDI/TOF mass spectra of whole cells and a range of physiological and biochemical characteristics. SMB34T also considerably differs from the recently described species T. xianhensis, with the most striking differences in the DNA G + C content (53.7 +/- 1.0 vs. 61.2 +/- 1.0 mol.%) and predominant ubiquinones (Q-10 vs. Q-9). The data obtained suggest strain SMB34T (=VKM B-2527T = NBRC 106175T), designated as the type strain, represents a novel species, named Thalassospira permensis sp. nov.

Sodium lauryl ether sulfate (SLES) degradation by nitrate-reducing bacteria.

PubMed

Paulo, Ana M S; Aydin, Rozelin; Dimitrov, Mauricio R; Vreeling, Harm; Cavaleiro, Ana J; García-Encina, Pedro A; Stams, Alfons J M; Plugge, Caroline M

2017-06-01

The surfactant sodium lauryl ether sulfate (SLES) is widely used in the composition of detergents and frequently ends up in wastewater treatment plants (WWTPs). While aerobic SLES degradation is well studied, little is known about the fate of this compound in anoxic environments, such as denitrification tanks of WWTPs, nor about the bacteria involved in the anoxic biodegradation. Here, we used SLES as sole carbon and energy source, at concentrations ranging from 50 to 1000 mg L -1 , to enrich and isolate nitrate-reducing bacteria from activated sludge of a WWTP with the anaerobic-anoxic-oxic (A 2 /O) concept. In the 50 mg L -1 enrichment, Comamonas (50%), Pseudomonas (24%), and Alicycliphilus (12%) were present at higher relative abundance, while Pseudomonas (53%) became dominant in the 1000 mg L -1 enrichment. Aeromonas hydrophila strain S7, Pseudomonas stutzeri strain S8, and Pseudomonas nitroreducens strain S11 were isolated from the enriched cultures. Under denitrifying conditions, strains S8 and S11 degraded 500 mg L -1 SLES in less than 1 day, while strain S7 required more than 6 days. Strains S8 and S11 also showed a remarkable resistance to SLES, being able to grow and reduce nitrate with SLES concentrations up to 40 g L -1 . Strain S11 turned out to be the best anoxic SLES degrader, degrading up to 41% of 500 mg L -1 . The comparison between SLES anoxic and oxic degradation by strain S11 revealed differences in SLES cleavage, degradation, and sulfate accumulation; both ester and ether cleavage were probably employed in SLES anoxic degradation by strain S11.

Analysis of the core genome and pangenome of Pseudomonas putida.

PubMed

Udaondo, Zulema; Molina, Lázaro; Segura, Ana; Duque, Estrella; Ramos, Juan L

2016-10-01

Pseudomonas putida are strict aerobes that proliferate in a range of temperate niches and are of interest for environmental applications due to their capacity to degrade pollutants and ability to promote plant growth. Furthermore solvent-tolerant strains are useful for biosynthesis of added-value chemicals. We present a comprehensive comparative analysis of nine strains and the first characterization of the Pseudomonas putida pangenome. The core genome of P. putida comprises approximately 3386 genes. The most abundant genes within the core genome are those that encode nutrient transporters. Other conserved genes include those for central carbon metabolism through the Entner-Doudoroff pathway, the pentose phosphate cycle, arginine and proline metabolism, and pathways for degradation of aromatic chemicals. Genes that encode transporters, enzymes and regulators for amino acid metabolism (synthesis and degradation) are all part of the core genome, as well as various electron transporters, which enable aerobic metabolism under different oxygen regimes. Within the core genome are 30 genes for flagella biosynthesis and 12 key genes for biofilm formation. Pseudomonas putida strains share 85% of the coding regions with Pseudomonas aeruginosa; however, in P. putida, virulence factors such as exotoxins and type III secretion systems are absent. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Virulence of plant pathogenic bacteria attenuated by degradation of fatty acid cell-to-cell signaling factors.

PubMed

Newman, Karyn L; Chatterjee, Subhadeep; Ho, Kimberly A; Lindow, Steven E

2008-03-01

Diffusible signal factor (DSF) is a fatty acid signal molecule involved in regulation of virulence in several Xanthomonas species as well as Xylella fastidiosa. In this study, we identified a variety of bacteria that could disrupt DSF-mediated induction of virulence factors in Xanthomonas campestris pv. campestris. While many bacteria had the ability to degrade DSF, several bacterial strains belonging to genera Bacillus, Paenibacillus, Microbacterium, Staphylococcus, and Pseudomonas were identified that were capable of particularly rapid degradation of DSF. The molecular determinants for rapid degradation of DSF in Pseudomonas spp. strain G were elucidated. Random transposon mutants of strain G lacking the ability to degrade DSF were isolated. Cloning and characterization of disrupted genes in these strains revealed that carAB, required for the synthesis of carbamoylphosphate, a precursor for pyrimidine and arginine biosynthesis is required for rapid degradation of DSF in strain G. Complementation of carAB mutants restored both pyrimidine prototrophy and DSF degradation ability of the strain G mutant. An Escherichia coli strain harboring carAB of Pseudomonas spp. strain G degrades DSF more rapidly than the parental strain, and overexpression of carAB in trans increased the ability of Pseudomonas spp. strain G to degrade as compared with the parental strain. Coinoculation of X. campestris pv. campestris with DSF-degrading bacteria into mustard and cabbage leaves reduced disease severity up to twofold compared with plants inoculated only with the pathogen. Likewise, disease incidence and severity in grape stems coinoculated with Xylella fastidiosa and DSF-degrading strains were significantly reduced compared with plants inoculated with the pathogen alone. Coinoculation of grape plants with a carAB mutant of Pseudomonas spp. strain G complemented with carAB in trans reduced disease severity as well or better than the parental strain. These results indicate that

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

Genetically engineered Pseudomonas putida X3 strain and its potential ability to bioremediate soil microcosms contaminated with methyl parathion and cadmium.

PubMed

Zhang, Rong; Xu, Xingjian; Chen, Wenli; Huang, Qiaoyun

2016-02-01

A multifunctional Pseudomonas putida X3 strain was successfully engineered by introducing methyl parathion (MP)-degrading gene and enhanced green fluorescent protein (EGFP) gene in P. putida X4 (CCTCC: 209319). In liquid cultures, the engineered X3 strain utilized MP as sole carbon source for growth and degraded 100 mg L(-1) of MP within 24 h; however, this strain did not further metabolize p-nitrophenol (PNP), an intermediate metabolite of MP. No discrepancy in minimum inhibitory concentrations (MICs) to cadmium (Cd), copper (Cu), zinc (Zn), and cobalt (Co) was observed between the engineered X3 strain and its host strain. The inoculated X3 strain accelerated MP degradation in different polluted soil microcosms with 100 mg MP kg(-1) dry soil and/or 5 mg Cd kg(-1) dry soil; MP was completely eliminated within 40 h. However, the presence of Cd in the early stage of remediation slightly delayed MP degradation. The application of X3 strain in Cd-contaminated soil strongly affected the distribution of Cd fractions and immobilized Cd by reducing bioavailable Cd concentrations with lower soluble/exchangeable Cd and organic-bound Cd. The inoculated X3 strain also colonized and proliferated in various contaminated microcosms. Our results suggested that the engineered X3 strain is a potential bioremediation agent showing competitive advantage in complex contaminated environments.

N-hexanoyl-L-homoserine lactone-degrading Pseudomonas aeruginosa PsDAHP1 protects zebrafish against Vibrio parahaemolyticus infection.

PubMed

Vinoj, Gopalakrishnan; Jayakumar, Rengarajan; Chen, Jiann-Chu; Withyachumnarnkul, Boonsirm; Shanthi, Sathappan; Vaseeharan, Baskaralingam

2015-01-01

Four strains of N-hexanoyl-L-homoserine lactone (AHL)-degrading Pseudomonas spp., named PsDAHP1, PsDAHP2, PsDAHP3, and PsDAHP4 were isolated and identified from the intestine of Fenneropenaeus indicus. PsDAHP1 showed the highest AHL-degrading activity among the four isolates. PsDAHP1 inhibited biofilm-forming exopolysaccharide and altered cell surface hydrophobicity of virulent green fluorescent protein (GFP)-tagged Vibrio parahaemolyticus DAHV2 (GFP-VpDAHV2). Oral administration of PsDAHP1 significantly reduced zebrafish mortality caused by GFP-VpDAHV2 challenge, and inhibited colonisation of GFP-VpDAHV2 in the gills and intestine of zebrafish as evidence by confocal laser scanning microscope and selective plating. Furthermore, zebrafish receiving PsDAHP1-containing feed had increased phagocytic cells of its leucocytes, increased serum activities of superoxide dismutase and lysozyme. The results suggest that Pseudomonas aeruginosa PsDAHP1 could protect zebrafish from V. parahaemolyticus infection by inhibiting biofilm formation and enhancing defence mechanisms of the fish. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Degradation of polyurethane by bacterium isolated from soil and assessment of polyurethanolytic activity of a Pseudomonas putida strain.

PubMed

Peng, Yu-Huei; Shih, Yang-hsin; Lai, Yen-Chun; Liu, Yuan-Zan; Liu, Ying-Tong; Lin, Nai-Chun

2014-01-01

The increasing usage and the persistence of polyester polyurethane (PU) generate significant sources of environmental pollution. The effective and environmental friendly bioremediation techniques for this refractory waste are in high demand. In this study, three novel PU degrading bacteria were isolated from farm soils and activated sludge. Based upon 16S ribosomal RNA gene sequence blast, their identities were determined. Particularly robust activity was observed in Pseudomonas putida; it spent 4 days to degrade 92% of Impranil DLN(TM) for supporting its growth. The optimum temperature and pH for DLN removal by P. putida were 25 °C and 8.4, respectively. The degradation and transformation of DLN investigated by Fourier transformed infrared spectroscopy show the decrease in ester functional group and the emergence of amide group. The polyurethanolytic activities were both presented in the extracellular fraction and in the cytosol. Esterase activity was detected in the cell lysate. A 45-kDa protein bearing polyurethanolytic activity was also detected in the extracellular medium. This study presented high PU degrading activity of P. putida and demonstrated its responsible enzymes during the PU degradation process, which could be applied in the bioremediation and management of plastic wastes.

Isolation and Characterization of Pseudomonas spp. Strains That Efficiently Decompose Sodium Dodecyl Sulfate

PubMed Central

Furmanczyk, Ewa M.; Kaminski, Michal A.; Spolnik, Grzegorz; Sojka, Maciej; Danikiewicz, Witold; Dziembowski, Andrzej; Lipinski, Leszek; Sobczak, Adam

2017-01-01

Due to their particular properties, detergents are widely used in household cleaning products, cosmetics, pharmaceuticals, and in agriculture as adjuvants tailoring the features of pesticides or other crop protection agents. The continuously growing use of these various products means that water soluble detergents have become one of the most problematic groups of pollutants for the aquatic and terrestrial environments. Thus it is important to identify bacteria having the ability to survive in the presence of large quantities of detergent and efficiently decompose it to non-surface active compounds. In this study, we used peaty soil sampled from a surface flow constructed wetland in a wastewater treatment plant to isolate bacteria that degrade sodium dodecyl sulfate (SDS). We identified and initially characterized 36 Pseudomonas spp. strains that varied significantly in their ability to use SDS as their sole carbon source. Five isolates having the closest taxonomic relationship to the Pseudomonas jessenii subgroup appeared to be the most efficient SDS degraders, decomposing from 80 to 100% of the SDS present in an initial concentration 1 g/L in less than 24 h. These isolates exhibited significant differences in degree of SDS degradation, their resistance to high detergent concentration (ranging from 2.5 g/L up to 10 g/L or higher), and in chemotaxis toward SDS on a plate test. Mass spectrometry revealed several SDS degradation products, 1-dodecanol being dominant; however, traces of dodecanal, 2-dodecanol, and 3-dodecanol were also observed, but no dodecanoic acid. Native polyacrylamide gel electrophoresis zymography revealed that all of the selected isolates possessed alkylsulfatase-like activity. Three isolates, AP3_10, AP3_20, and AP3_22, showed a single band on native PAGE zymography, that could be the result of alkylsulfatase activity, whereas for isolates AP3_16 and AP3_19 two bands were observed. Moreover, the AP3_22 strain exhibited a band in presence of

Draft Genome Sequences of Pseudomonas fluorescens BS2 and Pusillimonas noertemannii BS8, Soil Bacteria That Cooperate To Degrade the Poly-γ-d-Glutamic Acid Anthrax Capsule.

PubMed

Stabler, Richard A; Negus, David; Pain, Arnab; Taylor, Peter W

2013-01-01

A mixed culture of Pseudomonas fluorescens BS2 and Pusillimonas noertemannii BS8 degraded poly-γ-d-glutamic acid; when the 2 strains were cultured separately, no hydrolytic activity was apparent. Here we report the draft genome sequences of both soil isolates.

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).

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.

Influence of volatile organic compounds emitted by Pseudomonas and Serratia strains on Agrobacterium tumefaciens biofilms.

PubMed

Plyuta, Vladimir; Lipasova, Valentina; Popova, Alexandra; Koksharova, Olga; Kuznetsov, Alexander; Szegedi, Erno; Chernin, Leonid; Khmel, Inessa

2016-07-01

The ability to form biofilms plays an important role in bacteria-host interactions, including plant pathogenicity. In this work, we investigated the action of volatile organic compounds (VOCs) produced by rhizospheric strains of Pseudomonas chlororaphis 449, Pseudomonas fluorescens B-4117, Serratia plymuthica IC1270, as well as Serratia proteamaculans strain 94, isolated from spoiled meat, on biofilms formation by three strains of Agrobacterium tumefaciens which are causative agents of crown-gall disease in a wide range of plants. In dual culture assays, the pool of volatiles emitted by the tested Pseudomonas and Serratia strains suppressed the formation of biofilms of A. tumefaciens strains grown on polycarbonate membrane filters and killed Agrobacterium cells in mature biofilms. The individual VOCs produced by the tested Pseudomonas strains, that is, ketones (2-nonanone, 2-heptanone, 2-undecanone), and dimethyl disulfide (DMDS) produced by Serratia strains, were shown to kill A. tumefaciens cells in mature biofilms and suppress their formation. The data obtained in this study suggest an additional potential of some ketones and DMDS as protectors of plants against A. tumefaciens strains, whose virulence is associated with the formation of biofilms on the infected plants. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Biodegradation of naphthalene and anthracene by chemo-tactically active rhizobacteria of populus deltoides

PubMed Central

Bisht, Sandeep; Pandey, Piyush; Sood, Anchal; Sharma, Shivesh; Bisht, N. S.

2010-01-01

Several naphthalene and anthracene degrading bacteria were isolated from rhizosphere of Populus deltoides, which were growing in non-contaminated soil. Among these, four isolates, i.e. Kurthia sp., Micrococcus varians, Deinococcus radiodurans and Bacillus circulans utilized chrysene, benzene, toluene and xylene, in addition to anthracene and naphthalene. Kurthia sp and B. circulans showed positive chemotactic response for naphthalene and anthracene. The mean growth rate constant (K) of isolates were found to increase with successive increase in substrate concentration (0.5 to 1.0 mg/50ml). B. circulans SBA12 and Kurthia SBA4 degraded 87.5% and 86.6% of anthracene while, Kurthia sp. SBA4, B. circulans SBA12, and M. varians SBA8 degraded 85.3 %, 95.8 % and 86.8 % of naphthalene respectively after 6 days of incubation as determined by HPLC analysis. PMID:24031572

Aromatic-degrading Sphingomonas isolates from the deep subsurface

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

Fredrickson, J.K.; Romine, M.F.; Balkwill, D.L.

An obligately aerobic chemoheterotrophic bacterium (strain F199) previously isolated from Southeast Coastal Plain subsurface sediments and shown to degrade toluene, naphthalene, and other aromatic compounds was characterized by analysis of its 16S rRNA nucleotide base sequence and cellular lipid composition. Strain F199 contained 2-OH14:0 and 18:1{omega}7c as the predominant cellular fatty acids and sphingolipids that are characteristic of the genus Sphingomonas. Phylogenetic analysis of its 16SrRNA sequence indicated that F199 was most closely related to Sphingomonas capsulata among the bacteria currently in the Ribosomal Database. Five additional isolates from deep Southeast Coastal Plain sediments were determined by 16S rRNA sequencemore » analysis to be closely related to F199. These strains also contained characteristic sphingolipids. Four of these five strains could also grow on a broad range of aromatic compounds and could mineralize [{sup 14C}]toluene and [{sup 14C}]naphthalene. S. capsulata (ATCC 14666), Sphingomonas paucimobiolis (ATCC 29837), and one of the subsurface isolates were unable to grow on any of the aromatic compounds or mineralize toluene or naphthalene. These results indicate that bacteria within the genus Sphingomonas are present in Southeast Coastal Plain subsurface sediments and that the capacity for degrading a broad range of substituted aromatic compounds appears to be common among Sphingomonas species from this environment. 41 refs., 2 figs., 5 tabs.« less

Removal Capacities of Polycyclic Aromatic Hydrocarbons (PAHs) by a Newly Isolated Strain from Oilfield Produced Water

PubMed Central

Qi, Yi-Bin; Wang, Chen-Yu; Lv, Cheng-Yuan; Lun, Zeng-Min; Zheng, Cheng-Gang

2017-01-01

The polycyclic aromatic hydrocarbon (PAH)-degrading strain Q8 was isolated from oilfield produced water. According to the analysis of a biochemical test, 16S rRNA gene, house-keeping genes and DNA–DNA hybridization, strain Q8 was assigned to a novel species of the genus Gordonia. The strain could not only grow in mineral salt medium (MM) and utilize naphthalene and pyrene as its sole carbon source, but also degraded mixed naphthalene, phenanthrene, anthracene and pyrene. The degradation ratio of these four PAHs reached 100%, 95.4%, 73.8% and 53.4% respectively after being degraded by Q8 for seven days. A comparative experiment found that the PAHs degradation efficiency of Q8 is higher than that of Gordonia alkaliphila and Gordonia paraffinivorans, which have the capacities to remove PAHs. Fourier transform infrared spectra, saturate, aromatic, resin and asphaltene (SARA) and gas chromatography–mass spectrometry (GC–MS) analysis of crude oil degraded by Q8 were also studied. The results showed that Q8 could utilize n-alkanes and PAHs in crude oil. The relative proportions of the naphthalene series, phenanthrene series, thiophene series, fluorene series, chrysene series, C21-triaromatic steroid, pyrene, and benz(a)pyrene were reduced after being degraded by Q8. Gordonia sp. nov. Q8 had the capacity to remediate water and soil environments contaminated by PAHs or crude oil, and provided a feasible way for the bioremediation of PAHs and oil pollution. PMID:28241412

Naphthalene biodegradation in temperate and arctic marine microcosms.

PubMed

Bagi, Andrea; Pampanin, Daniela M; Lanzén, Anders; Bilstad, Torleiv; Kommedal, Roald

2014-02-01

Naphthalene, the smallest polycyclic aromatic hydrocarbon (PAH), is found in abundance in crude oil, its major source in marine environments. PAH removal occurs via biodegradation, a key process determining their fate in the sea. Adequate estimation of PAH biodegradation rates is essential for environmental risk assessment and response planning using numerical models such as the oil spill contingency and response (OSCAR) model. Using naphthalene as a model compound, biodegradation rate, temperature response and bacterial community composition of seawaters from two climatically different areas (North Sea and Arctic Ocean) were studied and compared. Naphthalene degradation was followed by measuring oxygen consumption in closed bottles using the OxiTop(®) system. Microbial communities of untreated and naphthalene exposed samples were analysed by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) and pyrosequencing. Three times higher naphthalene degradation rate coefficients were observed in arctic seawater samples compared to temperate, at all incubation temperatures. Rate coefficients at in situ temperatures were however, similar (0.048 day(-1) for temperate and 0.068 day(-1) for arctic). Naphthalene biodegradation rates decreased with similar Q10 ratios (3.3 and 3.5) in both seawaters. Using the temperature compensation method implemented in the OSCAR model, Q10 = 2, biodegradation in arctic seawater was underestimated when calculated from the measured temperate k1 value, showing that temperature difference alone could not predict biodegradation rates adequately. Temperate and arctic untreated seawater communities were different as revealed by pyrosequencing. Geographic origin of seawater affected the community composition of exposed samples.

Soil burial method for plastic degradation performed by Pseudomonas PL-01, Bacillus PL-01, and indigenous bacteria

NASA Astrophysics Data System (ADS)

Shovitri, Maya; Nafi'ah, Risyatun; Antika, Titi Rindi; Alami, Nur Hidayatul; Kuswytasari, N. D.; Zulaikha, Enny

2017-06-01

Lately, plastic bag is becoming the most important pollutant for environment since it is difficult to be naturally degraded due to it consists of long hydrocarbon polymer chains. Our previous study indicated that our pure isolate Pseudomonas PL-01 and Bacillus PL-01 could degrade about 10% plastic bag. This present study was aimed to find out whether Pseudomonas PL01 and Bacillus PL01 put a positive effect to indigenous bacteria from marginal area in doing plastic degradation with a soil burial method. Beach sand was used as a representative marginal area, and mangrove sediment was used as a comparison. Plastics were submerged into unsterile beach sand with 10% of Pseudomonas PL-01 or Bacillus PL-01 containing liquid minimal salt medium (MSM) separately, while other plastics were submerged into unsterile mangrove sediments. After 4, 8, 12 and 16 weeks, their biofilm formation on their plastic surfaces and plastic degradation were measured. Results indicated that those 2 isolates put positive influent on biofilm formation and plastic degradation for indigenous beach sand bacteria. Bacillus PL-01 put higher influent than Pseudomonas PL-01. Plastic transparent was preferable degraded than black and white plastic bag `kresek'. But anyhow, indigenous mangrove soil bacteria showed the best performance in biofilm formation and plastic degradation, even without Pseudomonas PL-01 or Bacillus PL-01 addition. Fourier Transform Infrared (FTIR) analysis complemented the results; there were attenuated peaks with decreasing peaks transmittances. This FTIR peaks indicated chemical functional group changes happened among the plastic compounds after 16 weeks incubation time.

Structural investigation of the exopolysaccharide produced by Pseudomonas flavescens strain B62--degradation by a fungal cellulase and isolation of the oligosaccharide repeating unit.

PubMed

Cescutti, P; Toffanin, R; Fett, W F; Osman, S F; Pollesello, P; Paoletti, S

1998-02-01

Pseudomonas flavescens strain B62 (NCPPB 3063) is a recently described bacterium isolated from walnut blight cankers. This strain has been designated as the type strain of a Pseudomonas rRNA group-I species. Strain B62 produced a mixture of two exopolysaccharides, differing in weight average relative molecular mass and composition. Only the most abundant exopolysaccharide (90% by mass), corresponding to the one with the lower molecular mass, was investigated by use of methylation analysis, partial acid hydrolysis, and NMR spectroscopy. The polysaccharide was depolymerised by the action of the cellulase produced by Penicillum funiculosum and the oligosaccharide obtained, corresponding to the repeating unit, was characterised by NMR spectroscopy and ion-spray mass spectrometry. The repeating unit of the B62 exopolysaccharide is [structure in text] where X is glucose (75%) or mannose (25%), and Lac is lactate. The O-acetyl groups are present only on 75% of the repeating units, and they are linked to the C6 of the hexose residues in non-stoichiometric amounts.

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

TSCA Environmental Release Application (TERA) for Pseudomonas fluorescens strains HK44 and 5RL

EPA Pesticide Factsheets

TERAs submitted by the University of Tennessee and Micro Systems Technologies, LLC and given the tracking designation of R-04-01 and R-04-02. The strain will be tested to examine its ability to detect and monitor naphthalene and methyl salicylate.

Genomic Diversity of Biocontrol Strains of Pseudomonas spp. Isolated from Aerial or Root Surfaces of Plants

USDA-ARS?s Scientific Manuscript database

The striking ecological, metabolic, and biochemical diversity of Pseudomonas has intrigued microbiologists for many decades. To explore the genomic diversity of biocontrol strains of Pseudomonas spp., we derived high quality draft sequences of seven strains known to suppress plant disease. The str...

Biotransformation of trinitrotoluene (TNT) by Pseudomonas spp. isolated from a TNT-contaminated environment.

PubMed

Chien, Chih-Ching; Kao, Chih-Ming; Chen, De-Yu; Chen, Ssu Ching; Chen, Chien-Cheng

2014-05-01

The compound 2,4,6-trinitrotoluene (TNT) is a secondary explosive widely used worldwide for both military and civil purposes. As a result, residual TNT has been detected as an environmental pollutant in both soil and groundwater. The authors have isolated several microbial strains from soil contaminated with TNT by enrichment culture techniques using TNT as a carbon, nitrogen, and energy source. The contaminated soil contained approximately 1860 ppm TNT measured by high-performance liquid chromatography (HPLC). The initial identification of these isolates was determined by 16S rRNA gene comparison. The isolates mainly included species belonging to the genus Pseudomonas. Two strains (Pseudomonas putida strain TP1 and Pseudomonas aeruginosa strain TP6) were selected for further examination. Both strains demonstrated the ability to grow on the medium containing TNT as a carbon, energy, and nitrogen source and also clearly demonstrated the ability to degrade TNT. More than 90% of the TNT in the growth medium was degraded by both strains after 22 d incubation, as determined by HPLC. Additionally, the resting cells of P. putida TP1 and P. aeruginosa TP6 both significantly displayed the ability to transform (metabolize) TNT. © 2014 SETAC.

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

Degradation of phorbol esters by Pseudomonas aeruginosa PseA during solid-state fermentation of deoiled Jatropha curcas seed cake.

PubMed

Joshi, Chetna; Mathur, Priyanka; Khare, S K

2011-04-01

Large amount of seed cake is generated as by-product during biodiesel production from Jatropha seeds. Presence of toxic phorbol esters restricts its utilization as livestock feed. Safe disposal or meaningful utilization of this major by-product necessitates the degradation of these phorbol esters. The present study describes the complete degradation of phorbol esters by Pseudomonas aeruginosa PseA strain during solid state fermentation (SSF) of deoiled Jatropha curcas seed cake. Phorbol esters were completely degraded in nine days under the optimized SSF conditions viz. deoiled cake 5.0 g; moistened with 5.0 ml distilled water; inoculum 1.5 ml of overnight grown P. aeruginosa; incubation at temperature 30 °C, pH 7.0 and RH 65%. SSF of deoiled cake seems a potentially viable approach towards the complete degradation of the toxic phorbol esters. Copyright © 2011 Elsevier Ltd. All rights reserved.

Isolation and characterization of a glyphosate-degrading rhizosphere strain, Enterobacter cloacae K7.

PubMed

Kryuchkova, Yelena V; Burygin, Gennady L; Gogoleva, Natalia E; Gogolev, Yuri V; Chernyshova, Marina P; Makarov, Oleg E; Fedorov, Evgenii E; Turkovskaya, Olga V

2014-01-20

Plant-growth-promoting rhizobacteria exert beneficial effects on plants through their capacity for nitrogen fixation, phytohormone production, phosphate solubilization, and improvement of the water and mineral status of plants. We suggested that these bacteria may also have the potential to express degradative activity toward glyphosate, a commonly used organophosphorus herbicide. In this study, 10 strains resistant to a 10 mM concentration of glyphosate were isolated from the rhizoplane of various plants. Five of these strains--Alcaligenes sp. K1, Comamonas sp. K4, Azomonas sp. K5, Pseudomonas sp. K3, and Enterobacter cloacae K7--possessed a number of associative traits, including fixation of atmospheric nitrogen, solubilization of phosphates, and synthesis of the phytohormone indole-3-acetic acid. One strain, E. cloacae K7, could utilize glyphosate as a source of P. Gas-liquid chromatography showed that E. cloacae growth correlated with a decline in herbicide content in the culture medium (40% of the initial 5mM content), with no glyphosate accumulating inside the cells. Thin-layer chromatography analysis of the intermediate metabolites of glyphosate degradation found that E. cloacae K7 had a C-P lyase activity and degraded glyphosate to give sarcosine, which was then oxidized to glycine. In addition, strain K7 colonized the roots of common sunflower (Helianthus annuus L.) and sugar sorghum (Sorghum saccharatum Pers.), promoting the growth and development of sunflower seedlings. Our findings extend current knowledge of glyphosate-degrading rhizosphere bacteria and may be useful for developing a biotechnology for the cleanup and restoration of glyphosate-polluted soils. Copyright © 2013 Elsevier GmbH. All rights reserved.

Heavy metals resistant plasmid-mediated utilization of solar by Pseudomonas aeruginosa AA301.

PubMed

Abo-Amer, Aly E; Mohamed, Rehab M

2006-01-01

Solar-degrading bacteria, Pseudomonas aeruginosa strains, were isolated from Egyptian soil by Mineral Salt Medium (MSM) supplemented with Solar (motor fuel) from different oil-contaminated sites in Sohag province. The strain AA301 of Pseudomonas aeruginosa showed appreciable growth in MSM medium containing high concentrations of Solar ranging from 0.5 to 3% (v/v), with optimum concentration at 1.5%. Solar was used as a sole carbon source and a source of energy by the bacterium. The ability to degrade Solar was found to be associated with a single 60-kb plasmid designated pSOL15. The plasmid-cured variant, which was obtained by culturing in LB broth with kanamycin, lost the plasmid indicative the ability to degrade Solar must depend on this plasmid. The wild type isolate, Pseudomonas aeruginosa AA301 and transformant strain, have maximum growth (OD600 = approximately 2) on Solar, however the plasmid-cured variant did not have any significant growth on Solar. Moreover, resistance to a wide range of heavy metals such as Mn2+, Hg2+, Mg2+, Cd2+, Zn2+, and Ni2+ was also 60-kb plasmid-mediated. Therefore, the strain AA301 could be good candidate for remediation of some heavy metals and oil hydrocarbons in heavily polluted sites.

Isolation and evaluation of potent Pseudomonas species for bioremediation of phorate in amended soil.

PubMed

Jariyal, Monu; Gupta, V K; Jindal, Vikas; Mandal, Kousik

2015-12-01

Use of phorate as a broad spectrum pesticide in agricultural crops is finding disfavor due to persistence of both the principal compound as well as its toxic residues in soil. Three phorate utilizing bacterial species (Pseudomonas sp. strain Imbl 4.3, Pseudomonas sp. strain Imbl 5.1, Pseudomonas sp. strain Imbl 5.2) were isolated from field soils. Comparative phorate degradation analysis of these species in liquid cultures identified Pseudomonas sp. strain Imbl 5.1 to cause complete metabolization of phorate during seven days as compared to the other two species in 13 days. In soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil), Pseudomonas sp. strain Imbl 5.1 resulted in active metabolization of phorate by between 94.66% and 95.62% establishing the same to be a potent bacterium for significantly relieving soil from phorate residues. Metabolization of phorate to these phorate residues did not follow the first order kinetics. This study proves that Pseudomonas sp. strain Imbl 5.1 has huge potential for active bioremediation of phorate both in liquid cultures and agricultural soils. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

A comparative intracellular proteomic profiling of Pseudomonas aeruginosa strain ASP-53 grown on pyrene or glucose as sole source of carbon and identification of some key enzymes of pyrene biodegradation pathway.

PubMed

Mukherjee, Ashis K; Bhagowati, Pabitra; Biswa, Bhim Bahadur; Chanda, Abhishek; Kalita, Bhargab

2017-09-07

Pseudomonas aeruginosa strain ASP-53, isolated from a petroleum oil-contaminated soil sample, was found to be an efficient degrader of pyrene. PCR amplification of selected hydrocarbon catabolic genes (alkB gene, which encodes for monooxygenase, and the C12O, C23O, and PAH-RHDα genes encoding for the dioxygenase enzyme) from the genomic DNA of P. aeruginosa strain ASP-53 suggested its hydrocarbon degradation potential. The GC-MS analysis demonstrated 30.1% pyrene degradation by P. aeruginosa strain ASP-53 after 144h of incubation at pH6.5, 37°C. Expressions of 115 and 196 intracellular proteins were unambiguously identified and quantitated by shotgun proteomics analysis when the isolate was grown in medium containing pyrene and glucose, respectively. The pyrene-induced uniquely expressed and up-regulated proteins in P. aeruginosa strain ASP-53 in addition to substrate (pyrene) metabolism are also likely to be associated with different cellular functions for example-related to protein folding (molecular chaperone), stress response, metabolism of carbohydrate, proteins and amino acids, and fatty acids; transport of metabolites, energy generation such as ATP synthesis, electron transport and nitrate assimilation, and other oxidation-reduction reactions. Proteomic analyses identified some important enzymes involved in pyrene degradation by P. aeruginosa ASP-53 which shows that this bacterium follows the salicylate pathway of pyrene degradation. This study is the first report on proteomic analysis of pyrene biodegradation pathway by Pseudomonas aeruginosa, isolated from a petroleum-oil contaminated soil sample. The pathway displays partial similarity with deduced pyrene degradation mechanisms of Mycobacterium vanbaalenii PYR-1. The GC-MS analysis as well as PCR amplification of hydrocarbon catabolic genes substantiated the potency of the bacterium under study to effectively degrade high molecular weight, toxic PAH such as pyrene for its filed scale bioremediation

Engineering Pseudomonas putida KT2440 for simultaneous degradation of organophosphates and pyrethroids and its application in bioremediation of soil.

PubMed

Zuo, Zhenqiang; Gong, Ting; Che, You; Liu, Ruihua; Xu, Ping; Jiang, Hong; Qiao, Chuanling; Song, Cunjiang; Yang, Chao

2015-06-01

Agricultural soils are usually co-contaminated with organophosphate (OP) and pyrethroid pesticides. To develop a stable and marker-free Pseudomonas putida for co-expression of two pesticide-degrading enzymes, we constructed a suicide plasmid with expression cassettes containing a constitutive promoter J23119, an OP-degrading gene (mpd), a pyrethroid-hydrolyzing carboxylesterase gene (pytH) that utilizes the upp gene as a counter-selectable marker for upp-deficient P. putida. By introduction of suicide plasmid and two-step homologous recombination, both mpd and pytH genes were integrated into the chromosome of a robust soil bacterium P. putida KT2440 and no selection marker was left on chromosome. Functional expression of mpd and pytH in P. putida KT2440 was demonstrated by Western blot analysis and enzyme activity assays. Degradation experiments with liquid cultures showed that the mixed pesticides including methyl parathion, fenitrothion, chlorpyrifos, permethrin, fenpropathrin, and cypermethrin (0.2 mM each) were degraded completely within 48 h. The inoculation of engineered strain (10(6) cells/g) to soils treated with the above mixed pesticides resulted in a higher degradation rate than in noninoculated soils. All six pesticides could be degraded completely within 15 days in fumigated and nonfumigated soils with inoculation. Theses results highlight the potential of the engineered strain to be used for in situ bioremediation of soils co-contaminated with OP and pyrethroid pesticides.

High quality draft genome sequences of Pseudomonas fulva DSM 17717 T, Pseudomonas parafulva DSM 17004 T and Pseudomonas cremoricolorata DSM 17059 T type strains

DOE PAGES

Peña, Arantxa; Busquets, Antonio; Gomila, Margarita; ...

2016-09-01

Pseudomonas has the highest number of species out of any genus of Gram-negative bacteria and is phylogenetically divided into several groups. The Pseudomonas putida phylogenetic branch includes at least 13 species of environmental and industrial interest, plant-associated bacteria, insect pathogens, and even some members that have been found in clinical specimens. In the context of the Genomic Encyclopedia of Bacteria and Archaea project, we present the permanent, high-quality draft genomes of the type strains of 3 taxonomically and ecologically closely related species in the Pseudomonas putida phylogenetic branch: Pseudomonas fulva DSM 17717 T, Pseudomonas parafulva DSM 17004 T and Pseudomonasmore » cremoricolorata DSM 17059T. All three genomes are comparable in size (4.6-4.9Mb), with 4,119-4,459 protein-coding genes. Average nucleotide identity based on BLAST comparisons and digital genome-to-genome distance calculations are in good agreement with experimental DNA-DNA hybridization results. The genome sequences presented here will be very helpful in elucidating the taxonomy, phylogeny and evolution of the Pseudomonas putida species complex.« less

High quality draft genome sequences of Pseudomonas fulva DSM 17717 T, Pseudomonas parafulva DSM 17004 T and Pseudomonas cremoricolorata DSM 17059 T type strains

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

Peña, Arantxa; Busquets, Antonio; Gomila, Margarita

Pseudomonas has the highest number of species out of any genus of Gram-negative bacteria and is phylogenetically divided into several groups. The Pseudomonas putida phylogenetic branch includes at least 13 species of environmental and industrial interest, plant-associated bacteria, insect pathogens, and even some members that have been found in clinical specimens. In the context of the Genomic Encyclopedia of Bacteria and Archaea project, we present the permanent, high-quality draft genomes of the type strains of 3 taxonomically and ecologically closely related species in the Pseudomonas putida phylogenetic branch: Pseudomonas fulva DSM 17717 T, Pseudomonas parafulva DSM 17004 T and Pseudomonasmore » cremoricolorata DSM 17059T. All three genomes are comparable in size (4.6-4.9Mb), with 4,119-4,459 protein-coding genes. Average nucleotide identity based on BLAST comparisons and digital genome-to-genome distance calculations are in good agreement with experimental DNA-DNA hybridization results. The genome sequences presented here will be very helpful in elucidating the taxonomy, phylogeny and evolution of the Pseudomonas putida species complex.« less

Draft genome sequence of the phenazine-producing Pseudomonas fluorescens strain 2-79

USDA-ARS?s Scientific Manuscript database

Pseudomonas fluorescens strain 2-79, a natural isolate of the rhizosphere of wheat (Triticum aestivum L.), possesses antagonistic potential toward several fungal pathogens. We report the draft genome sequence of strain 2-79, which comprises 5,674 protein-coding sequences....

Removal of Nitrate in Simulated Water at Low Temperature by a Novel Psychrotrophic and Aerobic Bacterium, Pseudomonas taiwanensis Strain J

PubMed Central

He, Tengxia; Ye, Qing; Sun, Quan; Cai, Xi; Ni, Jiupai

2018-01-01

Low temperatures and high pH generally inhibit the biodenitrification. Thus, it is important to explore the psychrotrophic and alkali-resisting microorganism for degradation of nitrogen. This research was mainly focused on the identification of a psychrotrophic strain and preliminary explored its denitrification characteristics. The new strain J was isolated using the bromothymol blue solid medium and identified as Pseudomonas taiwanensis on the basis of morphology and phospholipid fatty acid as well as 16S rRNA gene sequence analyses, which is further testified to work efficiently for removing nitrate from wastewater at low temperature circumstances. This is the first report that Pseudomonas taiwanensis possessed excellent tolerance to low temperature, with 15°C as its optimum and 5°C as viable. The Pseudomonas taiwanensis showed unusual ability of aerobic denitrification with the nitrate removal efficiencies of 100% at 15°C and 51.61% at 5°C. Single factor experiments showed that the optimal conditions for denitrification were glucose as carbon source, 15°C, shaking speed 150 r/min, C/N 15, pH ≥ 7, and incubation quantity 2.0 × 106 CFU/mL. The nitrate and total nitrogen removal efficiencies were up to 100% and 93.79% at 15°C when glucose is served as carbon source. These results suggested that strain J had aerobic denitrification ability, as well as the notable ability to tolerate the low temperature and high pH. PMID:29789796

Removal of Nitrate in Simulated Water at Low Temperature by a Novel Psychrotrophic and Aerobic Bacterium, Pseudomonas taiwanensis Strain J.

PubMed

He, Tengxia; Ye, Qing; Sun, Quan; Cai, Xi; Ni, Jiupai; Li, Zhenlun; Xie, Deti

2018-01-01

Low temperatures and high pH generally inhibit the biodenitrification. Thus, it is important to explore the psychrotrophic and alkali-resisting microorganism for degradation of nitrogen. This research was mainly focused on the identification of a psychrotrophic strain and preliminary explored its denitrification characteristics. The new strain J was isolated using the bromothymol blue solid medium and identified as Pseudomonas taiwanensis on the basis of morphology and phospholipid fatty acid as well as 16S rRNA gene sequence analyses, which is further testified to work efficiently for removing nitrate from wastewater at low temperature circumstances. This is the first report that Pseudomonas taiwanensis possessed excellent tolerance to low temperature, with 15°C as its optimum and 5°C as viable. The Pseudomonas taiwanensis showed unusual ability of aerobic denitrification with the nitrate removal efficiencies of 100% at 15°C and 51.61% at 5°C. Single factor experiments showed that the optimal conditions for denitrification were glucose as carbon source, 15°C, shaking speed 150 r/min, C/N 15, pH ≥ 7, and incubation quantity 2.0 × 10 6  CFU/mL. The nitrate and total nitrogen removal efficiencies were up to 100% and 93.79% at 15°C when glucose is served as carbon source. These results suggested that strain J had aerobic denitrification ability, as well as the notable ability to tolerate the low temperature and high pH.

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

Reactions Involved in the Lower Pathway for Degradation of 4-Nitrotoluene by Mycobacterium Strain HL 4-NT-1

PubMed Central

He, Zhongqi; Spain, Jim C.

2000-01-01

In spite of the variety of initial reactions, the aerobic biodegradation of aromatic compounds generally yields dihydroxy intermediates for ring cleavage. Recent investigation of the degradation of nitroaromatic compounds revealed that some nitroaromatic compounds are initially converted to 2-aminophenol rather than dihydroxy intermediates by a number of microorganisms. The complete pathway for the metabolism of 2-aminophenol during the degradation of nitrobenzene by Pseudomonas pseudoalcaligenes JS45 has been elucidated previously. The pathway is parallel to the catechol extradiol ring cleavage pathway, except that 2-aminophenol is the ring cleavage substrate. Here we report the elucidation of the pathway of 2-amino-4-methylphenol (6-amino-m-cresol) metabolism during the degradation of 4-nitrotoluene by Mycobacterium strain HL 4-NT-1 and the comparison of the substrate specificities of the relevant enzymes in strains JS45 and HL 4-NT-1. The results indicate that the 2-aminophenol ring cleavage pathway in strain JS45 is not unique but is representative of the pathways of metabolism of other o-aminophenolic compounds. PMID:10877799

The isolation and functional identification on producing cellulase of Pseudomonas mendocina

PubMed Central

Zhang, Jianfeng; Hou, Hongyan; Chen, Guang; Wang, Shusheng; Zhang, Jiejing

2016-01-01

ABSTRACT The straw can be degraded efficiently into humus by powerful enzymes from microorganisms, resulting in the accelerated circulation of N,P,K and other effective elements in ecological system. We isolated a strain through screening the straw degradation strains from natural humic straw in the low temperature area in northeast of china, which can produce cellulase efficiently. The strain was identified as Pseudomonas mendocina by using morphological, physiological, biochemical test, and molecular biological test, with the functional clarification on producing cellulase for Pseudomonas mendocina for the first time. The enzyme force constant Km and the maximum reaction rate (Vmax) of the strain were 0.3261 g/L and 0.1525 mg/(min.L) through the enzyme activity detection, and the molecular weight of the enzyme produced by the strain were 42.4 kD and 20.4 kD based on SDS-PAGE. The effects of various ecological factors such as temperature, pH and nematodes on the enzyme produced by the strain in the micro ecosystem in plant roots were evaluated. The result showed that the optimum temperature was 28°C, and the best pH was 7.4∼7.8, the impact heavy metal was Pb2+ and the enzyme activity and biomass of Pseudomonas mendocina increased the movement and predation of nematodes. PMID:27710430

Plasmid-borne Tn5 insertion mutation resulting in accumulation of gentisate from salicylate.

PubMed Central

Monticello, D J; Bakker, D; Schell, M; Finnerty, W R

1985-01-01

Plasmid-borne Tn5 insertion mutants of a Pseudomonas species which accumulated 2,5-dihydroxybenzoate (gentisate) following growth on 2-hydroxybenzoate (salicylate) were obtained from a pool of mutants that were unable to grow on naphthalene. One such mutant was characterized further. The ability of this mutant to oxidize gentisate was 100-fold less than the ability of a Nah+ Sal+ strain harboring the unmutagenized plasmid, although both strains oxidized and grew on salicylate. These bacteria were presumably able to metabolize salicylate via catechol, since they possessed an inducible, plasmid-encoded catechol 2,3-dioxygenase. Our results suggest that there is an alternate, plasmid-encoded route of salicylate degradation via gentisate and that some plasmid-associated relationship between this pathway and naphthalene oxidation exists. PMID:2988437

Serological Typing of 31 Achromogenic and 40 Melanogenic Pseudomonas aeruginosa Strains

PubMed Central

Yabuuchi, Eiko; Miyajima, Noriko; Hotta, Hisako; Furu, Youichi

1971-01-01

Thirty-one achromogenic and 40 melanogenic Pseudomonas aeruginosa strains were studied with 10 monovalent typing sera (3). Twenty-one of the achromogenic (67.7%) and seven of the melanogenic (17.5%) strains were agglutinated by one of the 10 typing sera. Ten achromogenic and 33 melanogenic strains were not agglutinated by any of the 10 typing sera. As far as this set of antisera is concerned, the typability of achromogenic and melanogenic P. aeruginosa strains appears to be much lower than that of the chromogenic, nonmelanogenic strains of the species reported previously. PMID:5002137

Genetic analysis of chromosomal operons involved in degradation of aromatic hydrocarbons in Pseudomonas putida TMB

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

Polissi, A.; Bestetti, G.; Bertoni, G.

1990-11-01

The catabolic pathway for the degradation of aromatic hydrocarbons encoded by Pseudomonas putida TMB differs from the TOL plasmid-encoded pathway as far as regulation of the upper pathway is concerned. We found, by analyzing Tn5-induced mutants and by Southern blot hybridization with appropriate probes derived from the TOL plasmid pWWO, that the catabolic genes of strain TMB were located on the bacterial chromosome and not on the 84-kb plasmid harbored by this strain. The catabolic genes of TMB and pWWO had sequence homology, as shown by Southern blot hybridization, but different significantly in their restriction patterns. The analysis of themore » mutants suggests that a regulatory mechanism similar to that present in pWWO coexists in TMB with a second mode of regulation which is epistatic on the former and that the chromosomal region carrying the catabolic genes is prone to rearrangements and deletions.« less

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

Influence of bacteria on degradation of bioplastics

NASA Astrophysics Data System (ADS)

Blinková, M.; Boturová, K.

2017-10-01

The degradation rate of bioplastic in soil is closely related to the diversity of soil microbiota. To investigate the effect of soil bacterial on biodegradation, 4 bacterial strains of soil - Pseudomonas chlororaphis, Kocuria rosea, Cupriavidus necator and Bacillus cereus, were used to accelerate the decomposition of bioplastics manufactured from Polylactid acid (PLA) by direct action during 250 days. The best results were obtained with bacterial strains Cupriavidus necator and Pseudomonas chlororaphis that were isolated of lagoons with anthropogenic sediments.

Plant protection by the recombinant, root-colonizing Pseudomonas fluorescens F113rifPCB strain expressing arsenic resistance: improving rhizoremediation.

PubMed

Ryan, R P; Ryan, D; Dowling, D N

2007-12-01

The present study was designed to evaluate the stable insertion and expression of an arsenic resistance operon in the rhizosphere competent, PCB degrading strain Pseudomonas fluorescens F113rifPCB (F113rifPCB) and to investigate its ability to protect plants from arsenic. Introduction of the clone pUM3 (arsRDABC) into F113rifPCB was carried out by triparental conjugation. The resultant arsenic resistant strain was screened through a number of phenotypic tests including ability to grow on biphenyl, its rhizosphere competence and plant protection potential. Insertion and expression of arsenic resistant operon arsRDABC (from plasmid R773) into F113rifPCB strain has allowed this strain to grow, colonize the root and degrade biphenyl (100 mmol l(-1)) in the presence of sodium arsenate concentrations of up to 11.5 mmol l(-1). The strain retains its ability to colonize the rhizosphere of plants and appears to provide seed germination protection to arsenic which is not seen by the wild type. Owing to the significantly improved growth characteristics of both this rhizobacterium and plant species, the use of F113rifPCB-ars endowed with arsenic resistance capabilities may be a promising strategy to remediate mixed organic metal-contaminated sites. These types of strain could be used in the inoculation of metal accumulation plants for phytoremediation.

Characterization and degradation potential of diesel-degrading bacterial strains for application in bioremediation.

PubMed

Balseiro-Romero, María; Gkorezis, Panagiotis; Kidd, Petra S; Van Hamme, Jonathan; Weyens, Nele; Monterroso, Carmen; Vangronsveld, Jaco

2017-10-03

Bioremediation of polluted soils is a promising technique with low environmental impact, which uses soil organisms to degrade soil contaminants. In this study, 19 bacterial strains isolated from a diesel-contaminated soil were screened for their diesel-degrading potential, biosurfactant (BS) production, and biofilm formation abilities, all desirable characteristics when selecting strains for re-inoculation into hydrocarbon-contaminated soils. Diesel-degradation rates were determined in vitro in minimal medium with diesel as the sole carbon source. The capacity to degrade diesel range organics (DROs) of strains SPG23 (Arthobacter sp.) and PF1 (Acinetobacter oleivorans) reached 17-26% of total DROs after 10 days, and 90% for strain GK2 (Acinetobacter calcoaceticus). The amount and rate of alkane degradation decreased significantly with increasing carbon number for strains SPG23 and PF1. Strain GK2, which produced BSs and biofilms, exhibited a greater extent, and faster rate of alkane degradation compared to SPG23 and PF1. Based on the outcomes of degradation experiments, in addition to BS production, biofilm formation capacities, and previous genome characterizations, strain GK2 is a promising candidate for microbial-assisted phytoremediation of diesel-contaminated soils. These results are of particular interest to select suitable strains for bioremediation, not only presenting high diesel-degradation rates, but also other characteristics which could improve rhizosphere colonization.

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

Novel Dehalogenase Mechanism for 2,3-Dichloro-1-Propanol Utilization in Pseudomonas putida Strain MC4

PubMed Central

Arif, Muhammad Irfan; Samin, Ghufrana; van Leeuwen, Jan G. E.; Oppentocht, Jantien

2012-01-01

A Pseudomonas putida strain (MC4) that can utilize 2,3-dichloro-1-propanol (DCP) and several aliphatic haloacids and haloalcohols as sole carbon and energy source for growth was isolated from contaminated soil. Degradation of DCP was found to start with oxidation and concomitant dehalogenation catalyzed by a 72-kDa monomeric protein (DppA) that was isolated from cell lysate. The dppA gene was cloned from a cosmid library and appeared to encode a protein equipped with a signal peptide and that possessed high similarity to quinohemoprotein alcohol dehydrogenases (ADHs), particularly ADH IIB and ADH IIG from Pseudomonas putida HK. This novel dehalogenating dehydrogenase has a broad substrate range, encompassing a number of nonhalogenated alcohols and haloalcohols. With DCP, DppA exhibited a kcat of 17 s−1. 1H nuclear magnetic resonance experiments indicated that DCP oxidation by DppA in the presence of 2,6-dichlorophenolindophenol (DCPIP) and potassium ferricyanide [K3Fe(CN)6] yielded 2-chloroacrolein, which was oxidized to 2-chloroacrylic acid. PMID:22752160

Transcriptomic Analyses Elucidate Adaptive Differences of Closely Related Strains of Pseudomonas aeruginosa in Fuel.

PubMed

Gunasekera, Thusitha S; Bowen, Loryn L; Zhou, Carol E; Howard-Byerly, Susan C; Foley, William S; Striebich, Richard C; Dugan, Larry C; Ruiz, Oscar N

2017-05-15

Pseudomonas aeruginosa can utilize hydrocarbons, but different strains have various degrees of adaptation despite their highly conserved genome. P. aeruginosa ATCC 33988 is highly adapted to hydrocarbons, while P. aeruginosa strain PAO1, a human pathogen, is less adapted and degrades jet fuel at a lower rate than does ATCC 33988. We investigated fuel-specific transcriptomic differences between these strains in order to ascertain the underlying mechanisms utilized by the adapted strain to proliferate in fuel. During growth in fuel, the genes related to alkane degradation, heat shock response, membrane proteins, efflux pumps, and several novel genes were upregulated in ATCC 33988. Overexpression of alk genes in PAO1 provided some improvement in growth, but it was not as robust as that of ATCC 33988, suggesting the role of other genes in adaptation. Expression of the function unknown gene PA5359 from ATCC 33988 in PAO1 increased the growth in fuel. Bioinformatic analysis revealed that PA5359 is a predicted lipoprotein with a conserved Yx(FWY)xxD motif, which is shared among bacterial adhesins. Overexpression of the putative resistance-nodulation-division (RND) efflux pump PA3521 to PA3523 increased the growth of the ATCC 33988 strain, suggesting a possible role in fuel tolerance. Interestingly, the PAO1 strain cannot utilize n -C 8 and n -C 10 The expression of green fluorescent protein (GFP) under the control of alkB promoters confirmed that alk gene promoter polymorphism affects the expression of alk genes. Promoter fusion assays further confirmed that the regulation of alk genes was different in the two strains. Protein sequence analysis showed low amino acid differences for many of the upregulated genes, further supporting transcriptional control as the main mechanism for enhanced adaptation. IMPORTANCE These results support that specific signal transduction, gene regulation, and coordination of multiple biological responses are required to improve the survival

Transcriptomic Analyses Elucidate Adaptive Differences of Closely Related Strains of Pseudomonas aeruginosa in Fuel

PubMed Central

Gunasekera, Thusitha S.; Bowen, Loryn L.; Zhou, Carol E.; Howard-Byerly, Susan C.; Foley, William S.; Striebich, Richard C.; Dugan, Larry C.

2017-01-01

ABSTRACT Pseudomonas aeruginosa can utilize hydrocarbons, but different strains have various degrees of adaptation despite their highly conserved genome. P. aeruginosa ATCC 33988 is highly adapted to hydrocarbons, while P. aeruginosa strain PAO1, a human pathogen, is less adapted and degrades jet fuel at a lower rate than does ATCC 33988. We investigated fuel-specific transcriptomic differences between these strains in order to ascertain the underlying mechanisms utilized by the adapted strain to proliferate in fuel. During growth in fuel, the genes related to alkane degradation, heat shock response, membrane proteins, efflux pumps, and several novel genes were upregulated in ATCC 33988. Overexpression of alk genes in PAO1 provided some improvement in growth, but it was not as robust as that of ATCC 33988, suggesting the role of other genes in adaptation. Expression of the function unknown gene PA5359 from ATCC 33988 in PAO1 increased the growth in fuel. Bioinformatic analysis revealed that PA5359 is a predicted lipoprotein with a conserved Yx(FWY)xxD motif, which is shared among bacterial adhesins. Overexpression of the putative resistance-nodulation-division (RND) efflux pump PA3521 to PA3523 increased the growth of the ATCC 33988 strain, suggesting a possible role in fuel tolerance. Interestingly, the PAO1 strain cannot utilize n-C8 and n-C10. The expression of green fluorescent protein (GFP) under the control of alkB promoters confirmed that alk gene promoter polymorphism affects the expression of alk genes. Promoter fusion assays further confirmed that the regulation of alk genes was different in the two strains. Protein sequence analysis showed low amino acid differences for many of the upregulated genes, further supporting transcriptional control as the main mechanism for enhanced adaptation. IMPORTANCE These results support that specific signal transduction, gene regulation, and coordination of multiple biological responses are required to improve the

TSCA Experimental Release Application Approved for Pseudomonas putida Strains (fact sheet)

EPA Pesticide Factsheets

In 1998, EPA approved the TERAs R98-0004/5 submitted by the National Explosives Waste Technology & Evaluation Center (NEWTEC) and the Oak Ridge National Laboratory for field trials of two modified strains of Pseudomonas putida (P.putida).

Heterotrophic bacteria associated with the degradation of zooplankton fecal pellets in Lake Michigan. [Mysis relicta, pseudomonas

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

Ferrante, J.G.; Ptak, D.J.

1978-01-01

Heterotrophic microbes decompose most of the calanoid copepod fecal pellets produced in Lake Michigan before they reach the sediment. Rod-shaped nonfermenters isolated from copepod and Mysis relicta fecal pellets were identified as Pseudomonas maltophilia and Pseudomonas fluorescens species. No enterobacteriaceae or fungal hyphae were found on or in any pellets. This investigation suggests that Pseudomonas species are attached to and may degrade Mysis relicta and calanoid copepod fecal pellets in the water column of Lake Michigan.

Genetic Diversity among 3-Chloroaniline- and Aniline-Degrading Strains of the Comamonadaceae

PubMed Central

Boon, Nico; Goris, Johan; De Vos, Paul; Verstraete, Willy; Top, Eva M.

2001-01-01

We examined the diversity of the plasmids and of the gene tdnQ, involved in the oxidative deamination of aniline, in five bacterial strains that are able to metabolize both aniline and 3-chloroaniline (3-CA). Three strains have been described and identified previously, i.e., Comamonas testosteroni I2 and Delftia acidovorans CA28 and BN3.1. Strains LME1 and B8c were isolated in this study from linuron-treated soil and from a wastewater treatment plant, respectively, and were both identified as D. acidovorans. Both Delftia and Comamonas belong to the family Comamonadaceae. All five strains possess a large plasmid of ca. 100 kb, but the plasmids from only four strains could be transferred to a recipient strain by selection on aniline or 3-CA as a sole source of carbon and/or nitrogen. Plasmid transfer experiments and Southern hybridization revealed that the plasmid of strain I2 was responsible for total aniline but not 3-CA degradation, while the plasmids of strains LME1 and B8c were responsible only for the oxidative deamination of aniline. Several transconjugant clones that had received the plasmid from strain CA28 showed different degradative capacities: all transconjugants could use aniline as a nitrogen source, while only some of the transconjugants could deaminate 3-CA. For all four plasmids, the IS1071 insertion sequence of Tn5271 was found to be located on a 1.4-kb restriction fragment, which also hybridized with the tdnQ probe. This result suggests the involvement of this insertion sequence element in the dissemination of aniline degradation genes in the environment. By use of specific primers for the tdnQ gene from Pseudomonas putida UCC22, the diversity of the PCR-amplified fragments in the five strains was examined by denaturing gradient gel electrophoresis (DGGE). With DGGE, three different clusters of the tdnQ fragment could be distinguished. Sequencing data showed that the tdnQ sequences of I2, LME1, B8c, and CA28 were very closely related, while the

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

[Nah-plasmids of IncP-9 group from natural strains of Pseudomonas].

PubMed

Levchuk, A A; Bulyga, I M; Izmalkova, T Iu; Sevast'ianovich, Ia R; Kosheleva, I A; Thomas, C M; Titok, M A

2006-01-01

Use of polymerase chain reaction helped to establish that the most frequent among naphthalene utilizing bacteria, isolated on the territory of Belarus, are Nah-plasmids of IncP-9 incompatibility group and those with indefinite systematic belonging. With the help of classical test of incompatibility, restriction and sequence analyses three new subgroups within the IncP-9 group were discovered (zeta, eta and IncP-9-like replicons). Conducting of restriction analysis for amplification products of nahG and nahAc genes allowed us to reveal, in addition to known sequences of stated determinants, two new types of nahG gene. Restriction analysis performed on amplification products of 16S RNA genes (ARDRA method) showed that native hosts of Nah-plasmids of IncP-9 group are not only fluorescent bacteria from genus Pseudomonas (P. fluorescens, P. putida, P. aeruginosa, P. species), but also non-fluorescent bacteria with indefinite specific belonging.

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....

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.

Pseudomonas fluorescens strain CL145A - a biopesticide for the control of zebra and quagga mussels (Bivalvia: Dreissenidae).

PubMed

Molloy, Daniel P; Mayer, Denise A; Gaylo, Michael J; Morse, John T; Presti, Kathleen T; Sawyko, Paul M; Karatayev, Alexander Y; Burlakova, Lyubov E; Laruelle, Franck; Nishikawa, Kimi C; Griffin, Barbara H

2013-05-01

Zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis) are the "poster children" of high-impact aquatic invasive species. In an effort to develop an effective and environmentally acceptable method to control their fouling of raw-water conduits, we have investigated the potential use of bacteria and their natural metabolic products as selective biological control agents. An outcome of this effort was the discovery of Pseudomonas fluorescens strain CL145A - an environmental isolate that kills these dreissenid mussels by intoxication (i.e., not infection). In the present paper, we use molecular methods to reconfirm that CL145A is a strain of the species P. fluorescens, and provide a phylogenetic analysis of the strain in relation to other Pseudomonas spp. We also provide evidence that the natural product lethal to dreissenids is associated with the cell wall of P. fluorescens CL145A, is a heat-labile secondary metabolite, and has degradable toxicity within 24 h when applied to water. CL145A appears to be an unusual strain of P. fluorescens since it was the only one among the ten strains tested to cause high mussel mortality. Pipe trials conducted under once-through conditions indicated: (1) P. fluorescens CL145A cells were efficacious against both zebra and quagga mussels, with high mortalities achieved against both species, and (2) as long as the total quantity of bacterial cells applied during the entire treatment period was the same, similar mussel mortality could be achieved in treatments lasting 1.5-12.0 h, with longer treatment durations achieving lower mortalities. The efficacy data presented herein, in combination with prior demonstration of its low risk of non-target impact, indicate that P. fluorescens CL145A cells have significant promise as an effective and environmentally safe control agent against these invasive mussels. Copyright © 2012 Elsevier Inc. All rights reserved.

Lethality and Developmental Delay of Drosophila melanogaster Following Ingestion of Selected Pseudomonas fluorescens Strains

USDA-ARS?s Scientific Manuscript database

Pseudomonas fluorescens secretes antimicrobial compounds that promote plant health and provide protection from pathogens. We used a non-invasive feeding assay to study the toxicity of P. fluorescens strains Pf0-1, SBW25, and Pf-5 to Drosophila melanogaster. The three strains of P. fluorescens varie...

Degradation of soil cyanide by single and mixed cultures of Pseudomonas stutzeri and Bacillus subtilis.

PubMed

Nwokoro, Ogbonnaya; Dibua, Marie Esther Uju

2014-03-01

The aim of this investigation was to study whether certain bacteria could be used for cyanide degradation in soil. The bacteria Pseudomonas stutzeri and Bacillus subtilis were selected based on their good growth in a minimal medium containing 0.8 mg mL-1 potassium cyanide (KCN). In this study we tested their ability to reduce cyanide levels in a medium containing 1.5 mg mL-1 of KCN. Although both microorganisms reduced cyanide levels, Pseudomonas stutzeri was the more effective test organism. Later on, the selected cultures were grown, diluted and their various cell concentrations were used individually and in combination to test their ability of cyanide degradation in soil samples collected around a cassava processing mill. Bacillus subtilis caused degradation of soil cyanide from 0.218 mg g-1 soil immediately with an inoculum concentration of 0.1 (OD600nm) to 0.072 mg g-1 soil after 10 days with an inoculum concentration of 0.6 (OD600nm) implying a 66.9 % reduction. Pseudomonas stutzeri cell concentration of 0.1 (OD600nm) decreased soil cyanide from 0.218 mg g-1 soil initially to 0.061 mg g-1 soil after 10 days with an inoculum concentration of 0.6 (OD600nm) (72 % reduction). The mixed culture of the two bacteria produced the best degradation of soil cyanide from 0.218 mg g-1 soil sample with a combined inoculum concentration of 0.1 (OD600nm) initially to 0.025 mg g-1 soil with a combined inoculum concentration of 0.6 (OD600nm) after 10 days incubation resulting in an 88.5 % degradation of soil cyanide. The analysed bacteria displayed high cyanide degradation potential and may be useful for efficient decontamination of cyanide contaminated sites.

Anaerobic Degradation of Ethylbenzene by a New Type of Marine Sulfate-Reducing Bacterium

PubMed Central

Kniemeyer, Olaf; Fischer, Thomas; Wilkes, Heinz; Glöckner, Frank Oliver; Widdel, Friedrich

2003-01-01

Anaerobic degradation of the aromatic hydrocarbon ethylbenzene was studied with sulfate as the electron acceptor. Enrichment cultures prepared with marine sediment samples from different locations showed ethylbenzene-dependent reduction of sulfate to sulfide and always contained a characteristic cell type that formed gas vesicles towards the end of growth. A pure culture of this cell type, strain EbS7, was isolated from sediment from Guaymas Basin (Gulf of California). Complete mineralization of ethylbenzene coupled to sulfate reduction was demonstrated in growth experiments with strain EbS7. Sequence analysis of the 16S rRNA gene revealed a close relationship between strain EbS7 and the previously described marine sulfate-reducing strains NaphS2 and mXyS1 (similarity values, 97.6 and 96.2%, respectively), which grow anaerobically with naphthalene and m-xylene, respectively. However, strain EbS7 did not oxidize naphthalene, m-xylene, or toluene. Other compounds utilized by strain EbS7 were phenylacetate, 3-phenylpropionate, formate, n-hexanoate, lactate, and pyruvate. 1-Phenylethanol and acetophenone, the characteristic intermediates in anaerobic ethylbenzene degradation by denitrifying bacteria, neither served as growth substrates nor were detectable as metabolites by gas chromatography-mass spectrometry in ethylbenzene-grown cultures of strain EbS7. Rather, (1-phenylethyl)succinate and 4-phenylpentanoate were detected as specific metabolites in such cultures. Formation of these intermediates can be explained by a reaction sequence involving addition of the benzyl carbon atom of ethylbenzene to fumarate, carbon skeleton rearrangement of the succinate moiety (as a thioester), and loss of one carboxyl group. Such reactions are analogous to those suggested for anaerobic n-alkane degradation and thus differ from the initial reactions in anaerobic ethylbenzene degradation by denitrifying bacteria which employ dehydrogenations. PMID:12570993

Whole Genome Sequence Analysis of an Alachlor and Endosulfan Degrading Micrococcus sp. strain 2385 Isolated from Ochlockonee River, Florida

PubMed Central

Pathak, Ashish; Chauhan, Ashvini; Ewida, Ayman Y.I.; Stothard, Paul

2016-01-01

We recently isolated Micrococcus sp. strain 2385 from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides- alachlor [(2-chloro-2`,6`-diethylphenyl-N (methoxymethyl)acetanilide)] and endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain 2385, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of Micrococcus sp. strain 2385 consisted of 1,460,461,440 bases which assembled into 175 contigs with an N50 contig length of 50,109 bases and a coverage of 600x. The genome size of this strain was estimated at 2,431,226 base pairs with a G+C content of 72.8 and a total number of 2,268 putative genes. RAST annotated a total of 340 subsystems in the genome of strain 2385 along with the presence of 2,177 coding sequences. A genome wide survey indicated that that strain 2385 harbors a plethora of genes to degrade other pollutants including caprolactam, PAHs (such as naphthalene), styrene, toluene and several chloroaromatic compounds. PMID:27672405

Whole Genome Sequence Analysis of an Alachlor and Endosulfan Degrading Micrococcus sp. strain 2385 Isolated from Ochlockonee River, Florida.

PubMed

Pathak, Ashish; Chauhan, Ashvini; Ewida, Ayman Y I; Stothard, Paul

2016-01-01

We recently isolated Micrococcus sp. strain 2385 from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides- alachlor [(2-chloro-2`,6`-diethylphenyl-N (methoxymethyl)acetanilide)] and endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain 2385, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of Micrococcus sp. strain 2385 consisted of 1,460,461,440 bases which assembled into 175 contigs with an N50 contig length of 50,109 bases and a coverage of 600x. The genome size of this strain was estimated at 2,431,226 base pairs with a G+C content of 72.8 and a total number of 2,268 putative genes. RAST annotated a total of 340 subsystems in the genome of strain 2385 along with the presence of 2,177 coding sequences. A genome wide survey indicated that that strain 2385 harbors a plethora of genes to degrade other pollutants including caprolactam, PAHs (such as naphthalene), styrene, toluene and several chloroaromatic compounds.

Draft genome sequence of Pseudomonas sp. strain M47T1, carried by Bursaphelenchus xylophilus isolated from Pinus pinaster.

PubMed

Proença, Diogo Neves; Espírito Santo, Christophe; Grass, Gregor; Morais, Paula V

2012-09-01

The draft genome sequence of Pseudomonas sp. strain M47T1, carried by the Bursaphelenchus xylophilus pinewood nematode, the causative agent of pine wilt disease, is presented. In Pseudomonas sp. strain M47T1, genes that make this a plant growth-promoting bacterium, as well as genes potentially involved in nematotoxicity, were identified.

Amplified fragment length polymorphism fingerprinting of Pseudomonas strains from a poultry processing plant.

PubMed

Geornaras, I; Kunene, N F; von Holy, A; Hastings, J W

1999-09-01

Molecular typing has been used previously to identify and trace dissemination of pathogenic and spoilage bacteria associated with food processing. Amplified fragment length polymorphism (AFLP) is a novel DNA fingerprinting technique which is considered highly reproducible and has high discriminatory power. This technique was used to fingerprint 88 Pseudomonas fluorescens and Pseudomonas putida strains that were previously isolated from plate counts of carcasses at six processing stages and various equipment surfaces and environmental sources of a poultry abattoir. Clustering of the AFLP patterns revealed a high level of diversity among the strains. Six clusters (clusters I through VI) were delineated at an arbitrary Dice coefficient level of 0.65; clusters III (31 strains) and IV (28 strains) were the largest clusters. More than one-half (52.3%) of the strains obtained from carcass samples, which may have represented the resident carcass population, grouped together in cluster III. By contrast, 43.2% of the strains from most of the equipment surfaces and environmental sources grouped together in cluster IV. In most cases, the clusters in which carcass strains from processing stages grouped corresponded to the clusters in which strains from the associated equipment surfaces and/or environmental sources were found. This provided evidence that there was cross-contamination between carcasses and the abattoir environment at the DNA level. The AFLP data also showed that strains were being disseminated from the beginning to the end of the poultry processing operation, since many strains associated with carcasses at the packaging stage were members of the same clusters as strains obtained from carcasses after the defeathering stage.

Galacto-oligosaccharide hydrolysis by genetically-engineered alpha-galactosidase-producing Pseudomonas chlororaphis strains

USDA-ARS?s Scientific Manuscript database

Various Pseudomonas chlororaphis strains have been shown to produce rhamnolipid (a biosurfactant), poly(hydroxyalkanoate) (PHA; a biopolymer), and/or antifungal compounds for plants. An ability to metabolize galacto-oligosaccharides in soy molasses would allow P. chlororaphis to use the byproduct as...

[The antibacterial activity of oregano essential oil (Origanum heracleoticum L.) against clinical strains of Escherichia coli and Pseudomonas aeruginosa].

PubMed

Sienkiewicz, Monika; Wasiela, Małgorzata; Głowacka, Anna

2012-01-01

The aim of this study was to investigate the antibacterial properties of oregano (Origanum heracleoticum L.) essential oil against clinical strains of Escherichia coli and Pseudomonas aeruginosa. The antibacterial activity of oregano essential oil was investigate against 2 tested and 20 clinical bacterial strains of Escherichia coli and 20 clinical strains o Pseudomonas aeruginosa come from patients with different clinical conditions. The agar dilution method was used for microbial growth inhibition at various concentrations ofoil. Susceptibility testing to antibiotics was carried out using disc-diffusion method. The results of experiments showed that the tested oil was active against all of the clinical strains from both genus of bacteria, but strains of Escherichia coli were more sensitive to tested oil. Essential oil from Origanum heracleoticum L. inhibited the growth of Escherichia coli and Pseudomonas aeruginosa clinical strains with different patters of resistance. The obtained outcomes will enable further investigations using oregano essential oil obtained from Origanum heracleoticum L. as alternative antibacterial remedies enhancing healing process in bacterial infections and as an effective means for the prevention of antibiotic-resistant strain development.

Enhanced degradation of chlorpyrifos in rice (Oryza sativa L.) by five strains of endophytic bacteria and their plant growth promotional ability.

PubMed

Feng, Fayun; Ge, Jing; Li, Yisong; He, Shuang; Zhong, Jianfeng; Liu, Xianjing; Yu, Xiangyang

2017-10-01

Endophytic bacteria reside in plant tissues, such as roots, stems, leaves and seeds. Most of them can stimulate plant growth or alleviate phytotoxicity of pollutants. There are handful species with dual functions stimulating plant growth and degrading pollutants have been reported. Five endophytic bacteria were isolated from chlorpyrifos (CP) treated rice plants and identified as Pseudomonas aeruginosa strain RRA, Bacillus megaterium strain RRB, Sphingobacterium siyangensis strain RSA, Stenotrophomonas pavanii strain RSB and Curtobacterium plantarum strain RSC according to morphological characteristics, physiological and biochemical tests, and 16S rDNA phylogeny. All of them possessed some plant growth promotional traits, including indole acetic acid and siderophore production, secretion of phosphate solubilization and 1-aminocyclopropane-1-carboxylate deaminase. The bacteria were marked with the green fluorescent protein (gfp) gene and successfully colonized into rice plants. All isolates were able to degrade CP in vitro and in vivo. The five isolates degraded more than 90% of CP in 24 h when the initial concentration was lower than 5 mg/L. CP degradation was significantly enhanced in the infested rice plants and rice grains. The final CP residual was reduced up to 80% in the infested rice grains compared to the controls. The results indicate that these isolates are promising bio-inoculants for the removal or detoxification of CP residues in rice plants and grains. Copyright © 2017 Elsevier Ltd. All rights reserved.

Decomposition of naphthalene by dc gliding arc gas discharge.

PubMed

Yu, Liang; Li, Xiaodong; Tu, Xin; Wang, Yu; Lu, Shengyong; Yan, Jianhua

2010-01-14

Gliding arc discharge has been proved to be effective in treatment of gas and liquid contaminants. In this study, physical characteristics of dc gliding arc discharge and its application to naphthalene destruction are investigated with different external resistances and carrier gases. The decomposition rate increases with increasing of oxygen concentration and decreases with external resistance. This value can be achieved up to 92.3% at the external resistance of 50 kOmega in the oxygen discharge, while the highest destruction energy efficiency reaches 3.6 g (kW h)(-1) with the external resistance of 93 kOmega. Possible reaction pathways and degradation mechanisms in the plasma with different gases are proposed by qualitative analysis of postdestructed products. In the air and oxygen gliding arc discharges, the naphthalene degradation is mainly governed by reactions with oxygen-derived radicals.

Three Strains of Pseudomonas fluorescens Exhibit Differential Toxicity Against Drosophila melanogaster

USDA-ARS?s Scientific Manuscript database

Three strains of Pseudomonas fluorescens were tested for toxicity to Drosophila melanogaster in an insect feeding assay. Insect eggs were placed on the surface of a non-nutritive agar plate supplemented with a food source that was non-inoculated or inoculated with P. fluorescens Pf0-1, SBW25, or Pf-...

Evidence for the involvement of the anthranilate degradation pathway in Pseudomonas aeruginosa biofilm formation

PubMed Central

Costaglioli, Patricia; Barthe, Christophe; Claverol, Stephane; Brözel, Volker S; Perrot, Michel; Crouzet, Marc; Bonneu, Marc; Garbay, Bertrand; Vilain, Sebastien

2012-01-01

Bacterial biofilms are complex cell communities found attached to surfaces and surrounded by an extracellular matrix composed of exopolysaccharides, DNA, and proteins. We investigated the whole-genome expression profile of Pseudomonas aeruginosa sessile cells (SCs) present in biofilms developed on a glass wool substratum. The transcriptome and proteome of SCs were compared with those of planktonic cell cultures. Principal component analysis revealed a biofilm-specific gene expression profile. Our study highlighted the overexpression of genes controlling the anthranilate degradation pathway in the SCs grown on glass wool for 24 h. In this condition, the metabolic pathway that uses anthranilate for Pseudomonas quinolone signal production was not activated, which suggested that anthranilate was primarily being consumed for energy metabolism. Transposon mutants defective for anthranilate degradation were analyzed in a simple assay of biofilm formation. The phenotypic analyses confirmed that P. aeruginosa biofilm formation partially depended on the activity of the anthranilate degradation pathway. This work points to a new feature concerning anthranilate metabolism in P. aeruginosa SCs. PMID:23170231

Biosurfactant production by Pseudomonas strains isolated from floral nectar.

PubMed

Ben Belgacem, Z; Bijttebier, S; Verreth, C; Voorspoels, S; Van de Voorde, I; Aerts, G; Willems, K A; Jacquemyn, H; Ruyters, S; Lievens, B

2015-06-01

To screen and identify biosurfactant-producing Pseudomonas strains isolated from floral nectar; to characterize the produced biosurfactants; and to investigate the effect of different carbon sources on biosurfactant production. Four of eight nectar Pseudomonas isolates were found to produce biosurfactants. Phylogenetic analysis based on three housekeeping genes (16S rRNA gene, rpoB and gyrB) classified the isolates into two groups, including one group closely related to Pseudomonas fluorescens and another group closely related to Pseudomonas fragi and Pseudomonas jessenii. Although our nectar pseudomonads were able to grow on a variety of water-soluble and water-immiscible carbon sources, surface active agents were only produced when using vegetable oil as sole carbon source, including olive oil, sunflower oil or waste frying sunflower oil. Structural characterization based on thin layer chromatography (TLC) and ultra high performance liquid chromatography-accurate mass mass spectrometry (UHPLC-amMS) revealed that biosurfactant activity was most probably due to the production of fatty acids (C16:0; C18:0; C18:1 and C18:2), and mono- and diglycerides thereof. Four biosurfactant-producing nectar pseudomonads were identified. The active compounds were identified as fatty acids (C16:0; C18:0; C18:1 and C18:2), and mono- and diglycerides thereof, produced by hydrolysis of triglycerides of the feedstock. Studies on biosurfactant-producing micro-organisms have mainly focused on microbes isolated from soils and aquatic environments. Here, for the first time, nectar environments were screened as a novel source for biosurfactant producers. As nectars represent harsh environments with high osmotic pressure and varying pH levels, further screening of nectar habitats for biosurfactant-producing microbes may lead to the discovery of novel biosurfactants with broad tolerance towards different environmental conditions. © 2015 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

Amplified Fragment Length Polymorphism Fingerprinting of Pseudomonas Strains from a Poultry Processing Plant

PubMed Central

Geornaras, Ifigenia; Kunene, Nokuthula F.; von Holy, Alexander; Hastings, John W.

1999-01-01

Molecular typing has been used previously to identify and trace dissemination of pathogenic and spoilage bacteria associated with food processing. Amplified fragment length polymorphism (AFLP) is a novel DNA fingerprinting technique which is considered highly reproducible and has high discriminatory power. This technique was used to fingerprint 88 Pseudomonas fluorescens and Pseudomonas putida strains that were previously isolated from plate counts of carcasses at six processing stages and various equipment surfaces and environmental sources of a poultry abattoir. Clustering of the AFLP patterns revealed a high level of diversity among the strains. Six clusters (clusters I through VI) were delineated at an arbitrary Dice coefficient level of 0.65; clusters III (31 strains) and IV (28 strains) were the largest clusters. More than one-half (52.3%) of the strains obtained from carcass samples, which may have represented the resident carcass population, grouped together in cluster III. By contrast, 43.2% of the strains from most of the equipment surfaces and environmental sources grouped together in cluster IV. In most cases, the clusters in which carcass strains from processing stages grouped corresponded to the clusters in which strains from the associated equipment surfaces and/or environmental sources were found. This provided evidence that there was cross-contamination between carcasses and the abattoir environment at the DNA level. The AFLP data also showed that strains were being disseminated from the beginning to the end of the poultry processing operation, since many strains associated with carcasses at the packaging stage were members of the same clusters as strains obtained from carcasses after the defeathering stage. PMID:10473382

Genome sequence of two members of the chloroaromatic-degrading MT community: Pseudomonas reinekei MT1 and Achromobacter xylosoxidans MT3.

PubMed

Gutierrez-Urrutia, Izabook; Miossec, Matthieu J; Valenzuela, Sandro L; Meneses, Claudio; Dos Santos, Vitor A P Martins; Castro-Nallar, Eduardo; Poblete-Castro, Ignacio

2018-06-10

We describe the genome sequence of Pseudomonas reinekei MT1 and Achromobacter xylosoxidans MT3, the most abundant members of a bacterial community capable of degrading chloroaromatic compounds. The MT1 genome contains open reading frames encoding enzymes responsible for the catabolism of chlorosalicylate, methylsalicylate, chlorophenols, phenol, benzoate, p-coumarate, phenylalanine, and phenylacetate. On the other hand, the MT3 strain genome possesses no ORFs to metabolize chlorosalicylates; instead the bacterium is capable of metabolizing nitro-phenolic and phenolic compounds, which can be used as the only carbon and energy source by MT3. We also confirmed that MT3 displays the genetic machinery for the metabolism of chlorocathecols and chloromuconates, where the latter are toxic compounds secreted by MT1 when degrading chlorosalicylates. Altogether, this work will advance our fundamental understanding of bacterial interactions. Copyright © 2018 Elsevier B.V. All rights reserved.

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.

Repeated batch and continuous degradation of chlorpyrifos by Pseudomonas putida.

PubMed

Pradeep, Vijayalakshmi; Subbaiah, Usha Malavalli

2015-01-01

The present study was undertaken with the objective of studying repeated batch and continuous degradation of chlorpyrifos (O,O-diethyl O-3,5,6-trichloropyridin-2-yl phosphorothioate) using Ca-alginate immobilized cells of Pseudomonas putida isolated from an agricultural soil, and to study the genes and enzymes involved in degradation. The study was carried out to reduce the toxicity of chlorpyrifos by degrading it to less toxic metabolites. Long-term stability of pesticide degradation was studied during repeated batch degradation of chlorpyrifos, which was carried out over a period of 50 days. Immobilized cells were able to show 65% degradation of chlorpyrifos at the end of the 50th cycle with a cell leakage of 112 × 10(3) cfu mL(-1). During continuous treatment, 100% degradation was observed at 100 mL h(-1) flow rate with 2% chlorpyrifos, and with 10% concentration of chlorpyrifos 98% and 80% degradation was recorded at 20 mL h(-1) and 100 mL h(-1) flow rate respectively. The products of degradation detected by liquid chromatography-mass spectrometry analysis were 3,5,6-trichloro-2-pyridinol and chlorpyrifos oxon. Plasmid curing experiments with ethidium bromide indicated that genes responsible for the degradation of chlorpyrifos are present on the chromosome and not on the plasmid. The results of Polymerase chain reaction indicate that a ~890-bp product expected for mpd gene was present in Ps. putida. Enzymatic degradation studies indicated that the enzymes involved in the degradation of chlorpyrifos are membrane-bound. The study indicates that immobilized cells of Ps. putida have the potential to be used in bioremediation of water contaminated with chlorpyrifos.

Evaluation of an antibiotic producing strain of Pseudomonas flourescens for suppression of plant-parasitic nematodes

USDA-ARS?s Scientific Manuscript database

The antibiotic 2,4-diacetylphloroglucinol (DAPG), produced by some strains of Pseudomonas spp., is involved in suppression of several fungal root pathogens as well as plant-parasitic nematodes. The primary objective of this study was to determine whether Wood1R, a D-genotype strain of DAPG-producin...

[Isolation of Pseudomonas aurantiaca strains capable of overproduction of phenazine antibiotics].

PubMed

Feklistova, I N; Maksimova, N P

2008-01-01

N-methyl-N'-nitro-N-nitrosoguanidine (NH)-induced mutagenesis with subsequent selection for resistance to toxic amino acid analogues (azaserine, m-fluoro-DL-phenylalanine, and 6-diazo-5-oxo-L-norleucine) was applied to Pseudomonas aurantiaca B-162. The resulting strains produced phenazine antibiotics three times more efficiently than the wild type strain and ten times more efficiently than the known pseudomonad strains. Overproduction of phenazine antibiotics was shown to result either from deregulation of 3-deoxi-D-arabinohepulosonate-7-phosphate synthase (DAHP synthase), the key enzyme of the aromatic pathway (removal of inhibition by phenylalanine, tyrosine, and phenazine), or overproduction of N-hexanoyl homoserine lactone, the regulatory molecule of positive control of cellular metabolism (QS system).

Detection of a Gentamicin-Resistant Burn Wound Strain of Pseudomonas Aeruginosa but Sensitive to Honey and Garcinia Kola (Heckel) Seed Extract

PubMed Central

Adeleke, O.E.; Coker, M.E.; Oke, O.B.

2010-01-01

Summary Studies on Staphylococcus aureus and Staphylococcus intermedius from dog and cat, and also on Staphylococcus aureus from wound and pyoderma infections, have shown a correlation between the site of microbial infection and antimicrobial susceptibility. Both the methanolic extract concentrate of Garcinia kola (Heckel) seeds and natural honey have been associated with activity on bacterial isolates from respiratory tract infections. In this study, selected bacteria belonging to genera from burn wound infection sites were treated with natural honey and methanolic extract concentrate of Garcinia kola in antimicrobial susceptibility tests separately and in combined form, and also with gentamicin and methanol as controls. The two natural products were found to be active on the bacterial isolates, excluding Klebsiella pneumoniae strains, all of which showed resistance to honey. Combination forms of the two natural products were active only on the strains of Pseudomonas aeruginosa. At 4 and 8 µg/ml, gentamicin was ineffective on the three strains of Klebsiella pneumoniae while 8 µg/ml was moderately active on only two strains of Pseudomonas aeruginosa. One strain of Pseudomonas aeruginosa, UCH002, was resistant to gentamicin beyond 1,000 µ/ml. Gentamicin at 4 µ/ml was inhibitory to one strain of Escherichia coli and two strains of Staphylococcus aureus. Though the antimicrobial activity of the two natural products tested had been previously reported against microbial agents of respiratory tract infection, it was also recorded in this study. The lack of activity of each of the three honey types used in this study against the Klebsiella pneumoniae strains tested underscores the need to exclude this organism from burn wound infections before embarking on treatment with honey. The sensitivity of one high-level gentamicin-resistant strain of Pseudomonas aeruginosa to honey and Garcinia kola seed extract was noteworthy considering the therapeutic failures of gentamicin

Naphthalene poisoning

MedlinePlus

Naphthalene is a white solid substance with a strong smell. Poisoning from naphthalene destroys or changes red blood cells so they cannot carry oxygen. This can cause organ damage. This article is for information only. DO NOT use it ...

Players over the Surface: Unraveling the Role of Exopolysaccharides in Zinc Biosorption by Fluorescent Pseudomonas Strain Psd.

PubMed

Upadhyay, Anamika; Kochar, Mandira; Rajam, Manchikatla V; Srivastava, Sheela

2017-01-01

Fluorescent Pseudomonas strain Psd is a soil isolate, possessing multiple plant growth promoting (PGP) properties and biocontrol potential. In addition, the strain also possesses high Zn 2+ biosorption capability. In this study, we have investigated the role exopolysaccharides (EPS) play in Zn 2+ biosorption. We have identified that alginates are the prime components contributing to Zn 2+ biosorption. Deletion of the alg8 gene, which codes for a sub-unit of alginate polymerase, led to a significant reduction in EPS production by the organism. We have also demonstrated that the increased alginate production in response to Zn 2+ exposure leads to improved biofilm formation by the strain. In the alg8 deletion mutant, however, biofilm formation was severely compromised. Further, we have studied the functional implications of Zn 2+ biosorption by Pseudomonas strain Psd by demonstrating the effect on the PGP and biocontrol potential of the strain.

Players over the Surface: Unraveling the Role of Exopolysaccharides in Zinc Biosorption by Fluorescent Pseudomonas Strain Psd

PubMed Central

Upadhyay, Anamika; Kochar, Mandira; Rajam, Manchikatla V.; Srivastava, Sheela

2017-01-01

Fluorescent Pseudomonas strain Psd is a soil isolate, possessing multiple plant growth promoting (PGP) properties and biocontrol potential. In addition, the strain also possesses high Zn2+ biosorption capability. In this study, we have investigated the role exopolysaccharides (EPS) play in Zn2+ biosorption. We have identified that alginates are the prime components contributing to Zn2+ biosorption. Deletion of the alg8 gene, which codes for a sub-unit of alginate polymerase, led to a significant reduction in EPS production by the organism. We have also demonstrated that the increased alginate production in response to Zn2+ exposure leads to improved biofilm formation by the strain. In the alg8 deletion mutant, however, biofilm formation was severely compromised. Further, we have studied the functional implications of Zn2+ biosorption by Pseudomonas strain Psd by demonstrating the effect on the PGP and biocontrol potential of the strain. PMID:28286498

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

Genome Sequence of the Biocontrol Strain Pseudomonas fluorescens F113

PubMed Central

Redondo-Nieto, Miguel; Barret, Matthieu; Morrisey, John P.; Germaine, Kieran; Martínez-Granero, Francisco; Barahona, Emma; Navazo, Ana; Sánchez-Contreras, María; Moynihan, Jennifer A.; Giddens, Stephen R.; Coppoolse, Eric R.; Muriel, Candela; Stiekema, Willem J.; Rainey, Paul B.; Dowling, David; O'Gara, Fergal; Martín, Marta

2012-01-01

Pseudomonas fluorescens F113 is a plant growth-promoting rhizobacterium (PGPR) that has biocontrol activity against fungal plant pathogens and is a model for rhizosphere colonization. Here, we present its complete genome sequence, which shows that besides a core genome very similar to those of other strains sequenced within this species, F113 possesses a wide array of genes encoding specialized functions for thriving in the rhizosphere and interacting with eukaryotic organisms. PMID:22328765

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

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.

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.

Screening of high concentration phenol degrading strain and optimization of its phenol degradation performance

NASA Astrophysics Data System (ADS)

Zhang, Yue-Hua; Li, Jing; Wang, Xue; Xue, Chun-Mei

2018-03-01

As phenol as the sole carbon source, the activated sludge was screened and acclimated to obtain the superior phenol-degrading bacteria capable of degrading high phenol concentration. The mixed bacteria completely degraded 1700mg/L phenol in 15h, to 102.9mg/L; the degradation rate reached 96.9%. After isolation and purification, four different single strains were obtained, and the genus of each strain was preliminarily identified. At the same time, the effects of initial phenol concentration, bacteria dosage, temperature and pH on the degradation of COD and phenol by phenol-degrading bacteria were also investigated. The mixed bacteria de-phenol effect is better than the four isolates were isolated.

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.

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.

[Comparative study of aromatic ring meta-cleavage enzymes in Pseudomonas strains with plasmid and chromosomal genetic control of the catabolism of biphenyl and m-toluate].

PubMed

Selifonov, S A; Starozoĭtov, I I

1990-12-01

It was shown that two different enzymes of aromatic ring oxidative meta-cleavage (2,3-dihydroxybiphenyl-1,2-dioxygenase), DBO and catechol-2,3-dioxygenase, C230) function in Pseudomonas strains with a plasmid and chromosomal genetic control of biphenyl and toluate catabolism. A comparative analysis of DBO's and C230's expressed by the pBS241 biphenyl degradative plasmid in P. putida BS893, pBS311 in P. putida U83, chromosomal genes in P. putida BF and C230 from P. putida PaW160 (pWWO) was carried out. It was found that the DBO's of all strains under study are highly specialized enzymes in respect of 2,3-dihydroxybiphenyl cleavage and are also able to cleave 3-methyl-catechol and catechol (but not 4-methylcatechol) at low rates. In contrast with DBO's, in Pseudomonas strains the substrate specificities of all C230's are variable. The C230's expressed by the D-plasmids pBS241 and pBC311 have a moderate affinity for catechol, 3-methyl- and 4-methylcatechol, but are unable to cleave 2,3-dihydroxybiphenyl. The C230 which is encoded by the chromosomal structure gene from P. putida BF is very similar to C230 which codes for the TOL-plasmid pWWO. These plasmid differ from C230's expressed by biphenyl D-plasmids due to their capability to cleave 2,3-dihydroxybiphenyl in addition to catechol cleavage. All DBO's and C230's under study possess a number of properties that are typical for the enzymes having an oxidative meta-cleaving effect. The different roles of these enzymes in biphenyl and toluate catabolism in Pseudomonas strains are discussed.

Exploring the In Vitro Thrombolytic Activity of Nattokinase From a New Strain Pseudomonas aeruginosa CMSS.

PubMed

Chandrasekaran, Subathra Devi; Vaithilingam, Mohanasrinivasan; Shanker, Ravi; Kumar, Sanjeev; Thiyur, Swathi; Babu, Vaishnavi; Selvakumar, Jemimah Naine; Prakash, Suyash

2015-10-01

Thrombolytic therapy has become a conventional treatment for acute myocardial infarction (AMI), yet currently, clinically prescribed thrombolytic drugs have problems such as delayed action and other side effects. Fibrinolytic enzymes have attracted interest as thrombolytic agents because of their efficiency in the fibrinolytic process, including plasmin activation. Nattokinase (NK) is a potent fibrinolytic agent for thrombosis therapy. The aim of this study was to enhance the production of NK from Pseudomonas aeruginosa CMSS by media optimization and strain improvement. In the present study, a potent NK-producing strain was isolated from cow milk and identified. To enhance the yield of NK, effect of various parameters such as pH, temperature, carbon source, nitrogen source and inoculum size were optimized. Strain improvement of P. aeruginosa CMSS was done by random UV-mutagenesis. Nattokinase was partially purified and the activity was determined by the casein digestion method, blood clot lysis and fibrin degradation assay. Based on morphological, biochemical and molecular characterization, the strain was confirmed as P. aeruginosa (GenBank accession number: JX112657), designated as P. aeruginosa CMSS. The optimum condition at pH 7 and temperature at 25˚C showed activity of NK as 1514 U mL(-1) and 1532 U mL(-1), respectively. Sucrose as the carbon source and shrimp shell powder (SSP) as the nitrogen source expressed NK activity of 1721 U mL(-1) and 2524 U mL(-1), respectively. At 1% inoculum size, the maximum rate of enzyme production was achieved with 2581 U mL(-1). The NK activity of the mutant strain UV60 was 4263 U mL(-1), indicating a two-fold increase in activity compared to the wild strain (2581 UmL(-1)). Nattokinase produced from mutant strain P. aeruginosa CMSS UV60 showed 94% blood clot lysis at ten minutes. The degradation of fibrin clot by the produced NK was observed after two hours of incubation. Sodium dodecyl sulfate polyacrylamide gel

Exploring the In Vitro Thrombolytic Activity of Nattokinase From a New Strain Pseudomonas aeruginosa CMSS

PubMed Central

Chandrasekaran, Subathra Devi; Vaithilingam, Mohanasrinivasan; Shanker, Ravi; Kumar, Sanjeev; Thiyur, Swathi; Babu, Vaishnavi; Selvakumar, Jemimah Naine; Prakash, Suyash

2015-01-01

Background: Thrombolytic therapy has become a conventional treatment for acute myocardial infarction (AMI), yet currently, clinically prescribed thrombolytic drugs have problems such as delayed action and other side effects. Fibrinolytic enzymes have attracted interest as thrombolytic agents because of their efficiency in the fibrinolytic process, including plasmin activation. Nattokinase (NK) is a potent fibrinolytic agent for thrombosis therapy. Objectives: The aim of this study was to enhance the production of NK from Pseudomonas aeruginosa CMSS by media optimization and strain improvement. Materials and Methods: In the present study, a potent NK-producing strain was isolated from cow milk and identified. To enhance the yield of NK, effect of various parameters such as pH, temperature, carbon source, nitrogen source and inoculum size were optimized. Strain improvement of P. aeruginosa CMSS was done by random UV-mutagenesis. Nattokinase was partially purified and the activity was determined by the casein digestion method, blood clot lysis and fibrin degradation assay. Results: Based on morphological, biochemical and molecular characterization, the strain was confirmed as P. aeruginosa (GenBank accession number: JX112657), designated as P. aeruginosa CMSS. The optimum condition at pH 7 and temperature at 25˚C showed activity of NK as 1514 U mL-1 and 1532 U mL-1, respectively. Sucrose as the carbon source and shrimp shell powder (SSP) as the nitrogen source expressed NK activity of 1721 U mL-1 and 2524 U mL-1, respectively. At 1% inoculum size, the maximum rate of enzyme production was achieved with 2581 U mL-1. The NK activity of the mutant strain UV60 was 4263 U mL-1, indicating a two-fold increase in activity compared to the wild strain (2581 UmL-1). Nattokinase produced from mutant strain P. aeruginosa CMSS UV60 showed 94% blood clot lysis at ten minutes. The degradation of fibrin clot by the produced NK was observed after two hours of incubation. Sodium

Antiphagocytic Effect of Slime from a Mucoid Strain of Pseudomonas aeruginosa

PubMed Central

Schwarzmann, Stephen; Boring, John R.

1971-01-01

Mucoid strains of Pseudomonas aeruginosa produce a viscid slime when grown on the surface of agar media. These strains are known to colonize persistently the tracheobronchial tree of children with cystic fibrosis. Colonization may result from inhibition of phagocytosis due to slime produced by the organism. Slime separated from one mucoid strain was examined to determine whether it possessed antiphagocytic activity in vitro. Cells of P. aeruginosa, Escherichia coli, and Staphylococcus aureus were rapidly phagocytized by rabbit polymorphonuclear leukocytes when mixtures were rotated for 2 hr at 37 C in the absence of slime. The addition of relatively small amounts of slime to bacteria and leukocytes inhibited phagocytosis as measured by phagocytic killing of the organisms. Inhibition was found to be most complete with P. aeruginosa. PMID:16558051

Optical biosensor for environmental on-line monitoring of naphthalene and salicylate bioavailability with an immobilized bioluminescent catabolic reporter bacterium.

PubMed Central

Heitzer, A; Malachowsky, K; Thonnard, J E; Bienkowski, P R; White, D C; Sayler, G S

1994-01-01

An optical whole-cell biosensor based on a genetically engineered bioluminescent catabolic reporter bacterium was developed for continuous on-line monitoring of naphthalene and salicylate bioavailability and microbial catabolic activity potential in waste streams. The bioluminescent reporter bacterium, Pseudomonas fluorescens HK44, carries a transcriptional nahG-luxCDABE fusion for naphthalene and salicylate catabolism. Exposure to either compound resulted in inducible bioluminescence. The reporter culture was immobilized onto the surface of an optical light guide by using strontium alginate. This biosensor probe was then inserted into a measurement cell which simultaneously received the waste stream solution and a maintenance medium. Exposure under defined conditions to both naphthalene and salicylate resulted in a rapid increase in bioluminescence. The magnitude of the response and the response time were concentration dependent. Good reproducibility of the response was observed during repetitive perturbations with either naphthalene or salicylate. Exposure to other compounds, such as glucose and complex nutrient medium or toluene, resulted in either minor bioluminescence increases after significantly longer response times compared with naphthalene or no response, respectively. The environmental utility of the biosensor was tested by using real pollutant mixtures. A specific bioluminescence response was obtained after exposure to either an aqueous solution saturated with JP-4 jet fuel or an aqueous leachate from a manufactured-gas plant soil, since naphthalene was present in both pollutant mixtures. PMID:8017932

Kinetics of substrate utilization and bacterial growth of crude oil degraded by Pseudomonas aeruginosa.

PubMed

Talaiekhozani, Amirreza; Jafarzadeh, Nematollah; Fulazzaky, Mohamad Ali; Talaie, Mohammad Reza; Beheshti, Masoud

2015-01-01

Pollution associated with crude oil (CO) extraction degrades the quality of waters, threatens drinking water sources and may ham air quality. The systems biology approach aims at learning the kinetics of substrate utilization and bacterial growth for a biological process for which very limited knowledge is available. This study uses the Pseudomonas aeruginosa to degrade CO and determines the kinetic parameters of substrate utilization and bacterial growth modeled from a completely mixed batch reactor. The ability of Pseudomonas aeruginosa can remove 91 % of the total petroleum hydrocarbons and 83 % of the aromatic compounds from oily environment. The value k of 9.31 g of substrate g(-1) of microorganism d(-1) could be far higher than the value k obtained for petrochemical wastewater treatment and that for municipal wastewater treatment. The production of new cells of using CO as the sole carbon and energy source can exceed 2(3) of the existing cells per day. The kinetic parameters are verified to contribute to improving the biological removal of CO from oily environment.

Analysis of competition in soil among 2,4-dichlorophenoxyacetic acid-degrading bacteria.

PubMed Central

Ka, J O; Holben, W E; Tiedje, J M

1994-01-01

Competition among indigenous and inoculated 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria was studied in a native Kansas prairie soil following 2,4-D additions. The soil was inoculated with four different 2,4-D-degrading strains at densities of 10(3) cells per g of soil; the organisms used were Pseudomonas cepacia DBO1(pJP4) and three Michigan soil isolates, strain 745, Sphingomonas paucimobilis 1443, and Pseudomonas pickettii 712. Following 2,4-D additions, total soil DNA was extracted and analyzed on Southern blots by using a tfdA gene probe which detected three of the strains and another probe that detected the fourth strain, S. paucimobilis 1443, which belongs to a different class of 2,4-D degraders. P. cepacia DBO1(pJP4), a constructed strain, outcompeted the other added strains and the indigenous 2,4-D-degrading populations. The S. paucimobilis population was the secondary dominant population, and strain 745 and P. pickettii were not detected. Relative fitness coefficients determined in axenic broth cultures predicted the outcome of competition in soil for some but not all strains. Lag time was shown to be a principal determinant of competitiveness among the strains, but the lag times were significantly reduced in mixed broth cultures, which changed the competitive outcome. Plasmids containing the genes for the 2,4-D pathway were important determinants of competitiveness since plasmid pKA4 in P. cepacia DBO1 resulted in the slower growth characteristic of its original host, P. pickettii, rather than the rapid growth observed when this strain harbors pJP4. Images PMID:8017909

Biodegradation of polycyclic aromatic hydrocarbons by Sphingomonas strains isolated from the terrestrial subsurface

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

Shi, T; Fredrickson, Jim K.; Balkwill, David L.

Several strains of Sphingomonas isolated from deep Atlantic coastal plain aquifers at the US Department of Energy Savannah River Site (SRS) near Aiken, SC were shown to degrade a variety of aromatic hydrocarbons in a liquid culture medium. Sphingomonas aromaticivorans strain B0695 was the most versatile of the five strains examined. This strain was able to degrade acenaphthene, anthracene, phenanthrene, 2,3-benzofluorene, 2-methyl naphthalene, 2,3-dimethylnaphthalene, and fluoranthene in the presence of 400 mg l(-1) Tween 80. Studies involving microcosms composed of aquifer sediments showed that S. aromaticivorans B0695 could degrade phenanthrene effectively in sterile sediment and could enhance the rate atmore » which this compound was degraded in nonsterile sediment. These findings indicate that it may be feasible to carry out (or, at least, to enhance) in situ bioremediation of phenanthrene-contaminated soils and subsurface environments with S. aromaticivorans B0695. In contrast, stra in B0695 was unable to degrade fluoranthene in microcosms containing aquifer sediments, even though it readily degraded this polynuclear aromatic hydrocarbon (PAH) in a defined liquid growth medium.« less

Chemotaxis Increases the Residence Time Distribution of Bacteria in Granular Media Containing Distributed Contaminant Sources

NASA Astrophysics Data System (ADS)

Adadevoh, J.; Triolo, S.; Ramsburg, C. A.; Ford, R.

2015-12-01

The use of chemotactic bacteria in bioremediation has the potential to increase access to, and biotransformation of, contaminant mass within the subsurface environment. This laboratory-scale study aimed to understand and quantify the influence of chemotaxis on residence times of pollutant-degrading bacteria within homogeneous treatment zones. Focus was placed on a continuous flow sand-packed column system in which a uniform distribution of naphthalene crystals created distributed sources of dissolved phase contaminant. A 10 mL pulse of Pseudomonas putida G7, which is chemotactic to naphthalene, and Pseudomonas putida G7 Y1, a non-chemotactic mutant strain, were simultaneously introduced into the sand-packed column at equal concentrations. Breakthrough curves obtained for the bacteria from column experiments conducted with and without naphthalene were used to quantify the effect of chemotaxis on transport parameters. In the presence of the chemoattractant, longitudinal dispersivity of PpG7 increased by a factor of 3 and percent recovery decreased from 21% to 12%. The results imply that pore-scale chemotaxis responses are evident at an interstitial fluid velocity of 1.7 m/d, which is within the range of typical groundwater flow. Within the context of bioremediation, chemotaxis may work to enhance bacterial residence times in zones of contamination thereby improving treatment.

Biodegradation of isoproturon using a novel Pseudomonas aeruginosa strain JS-11 as a multi-functional bioinoculant of environmental significance.

PubMed

Dwivedi, Sourabh; Singh, Braj Raj; Al-Khedhairy, Abdulaziz A; Musarrat, Javed

2011-01-30

Biodegradation of phenylurea herbicide isoproturon was studied in soil microcosm bioaugmented with a novel bacterial strain JS-11 isolated from wheat rhizosphere. The molecular characterization based on 16SrDNA sequence homology confirmed its identity as Pseudomonas aeruginosa strain JS-11. The herbicide was completely degraded within 20 days at ambient temperature with the rate constant of 0.08 day(-1), following the first-order rate kinetics. In stationary phase, at a cell density of 6.5 × 10(9) CFU mL(-1), the bacteria produced substantially increased amounts of indole acetic acid (IAA) in the presence of tryptophan as compared with the control. Also, the bacteria exhibited a time-dependent increase in the amount of tri-calcium phosphate solubilization in Pikovskaya's medium. Further screening of the strain JS-11 for auxiliary activities revealed its remarkable capability of producing the siderophores and hydrogen cyanide (HCN), besides antifungal activity against a common phytopathogen Fusarium oxysporum. Thus, the versatile P. aeruginosa strain JS-11 with innate potential for multifarious biological activities is envisaged as a super-bioinoculant for exploitation in the integrated bioremediation, plant growth and disease management (IBPDM) in contaminated agricultural soils. Copyright © 2010 Elsevier B.V. All rights reserved.

Entner–Doudoroff pathway for sulfoquinovose degradation in Pseudomonas putida SQ1

PubMed Central

Felux, Ann-Katrin; Spiteller, Dieter; Klebensberger, Janosch; Schleheck, David

2015-01-01

Sulfoquinovose (SQ; 6-deoxy-6-sulfoglucose) is the polar head group of the plant sulfolipid SQ-diacylglycerol, and SQ comprises a major proportion of the organosulfur in nature, where it is degraded by bacteria. A first degradation pathway for SQ has been demonstrated recently, a “sulfoglycolytic” pathway, in addition to the classical glycolytic (Embden–Meyerhof) pathway in Escherichia coli K-12; half of the carbon of SQ is abstracted as dihydroxyacetonephosphate (DHAP) and used for growth, whereas a C3-organosulfonate, 2,3-dihydroxypropane sulfonate (DHPS), is excreted. The environmental isolate Pseudomonas putida SQ1 is also able to use SQ for growth, and excretes a different C3-organosulfonate, 3-sulfolactate (SL). In this study, we revealed the catabolic pathway for SQ in P. putida SQ1 through differential proteomics and transcriptional analyses, by in vitro reconstitution of the complete pathway by five heterologously produced enzymes, and by identification of all four organosulfonate intermediates. The pathway follows a reaction sequence analogous to the Entner–Doudoroff pathway for glucose-6-phosphate: It involves an NAD+-dependent SQ dehydrogenase, 6-deoxy-6-sulfogluconolactone (SGL) lactonase, 6-deoxy-6-sulfogluconate (SG) dehydratase, and 2-keto-3,6-dideoxy-6-sulfogluconate (KDSG) aldolase. The aldolase reaction yields pyruvate, which supports growth of P. putida, and 3-sulfolactaldehyde (SLA), which is oxidized to SL by an NAD(P)+-dependent SLA dehydrogenase. All five enzymes are encoded in a single gene cluster that includes, for example, genes for transport and regulation. Homologous gene clusters were found in genomes of other P. putida strains, in other gamma-Proteobacteria, and in beta- and alpha-Proteobacteria, for example, in genomes of Enterobacteria, Vibrio, and Halomonas species, and in typical soil bacteria, such as Burkholderia, Herbaspirillum, and Rhizobium. PMID:26195800

[Prevalence of cytotoxicity effectors in nosocomial Pseudomonas Aeruginosa strains].

PubMed

Kuznetsova, M V; Maksimova, A V; Karpunina, T I; Demakov, V A

2014-01-01

Analysis of occurrence of the third type secretory system (TTSS) effectors in clinical P. aeruginosa strains. Intra-hospital (n = 164) and extra-hospital (n = 30) strains of P. aeruginosa were studied. Detection of exoS and exoU genes was carried out by PCR in DNA Engine Dyad Thermal Cycler ("Bio-Rad", USA). Metallo-beta-lactamase (MBL) producers were detected by the presence of blaVIM-2 gene. Screening of intra- and extra-hospital strains for the presence of genes coding ExoS and ExoU showed, that exoS is detected in genome of clinical isolates in 59.8% and exoU--31.1% of cases. At the same time, strains with exoS-/exoU+ genotype predominated in lCU (Φ = 0.466; p = 0.0000). A significant association between the presence of the respective effectors and material of strain isolation was not detected. exoU gene was more frequently detected in genome of MBL producers (Φ = 0.784; p = 0.0004). A significant association between exoU and blaVIM-2 could be explained by clonal prevalence of P. aeruginosa ST235 VIM-2, circulation of those is noted on all the territory of Russia. As a rule, ExoU is produced by highly virulent poly-antibiotic resistant hospital isolates that determine unfavorable outcomes of pseudomonas infection.

Endophytic colonization of olive roots by the biocontrol strain Pseudomonas fluorescens PICF7.

PubMed

Prieto, Pilar; Mercado-Blanco, Jesús

2008-05-01

Confocal microscopy combined with three-dimensional olive root tissue sectioning was used to provide evidence of the endophytic behaviour of Pseudomonas fluorescens PICF7, an effective biocontrol strain against Verticillium wilt of olive. Two derivatives of the green fluorescent protein (GFP), the enhanced green and the red fluorescent proteins, have been used to visualize simultaneously two differently fluorescently tagged populations of P. fluorescens PICF7 within olive root tissues at the single cell level. The time-course of colonization events of olive roots cv. Arbequina by strain PICF7 and the localization of tagged bacteria within olive root tissues are described. First, bacteria rapidly colonized root surfaces and were predominantly found in the differentiation zone. Thereafter, microscopy observations showed that PICF7-tagged populations eventually disappeared from the root surface, and increasingly colonized inner root tissues. Localized and limited endophytic colonization by the introduced bacteria was observed over time. Fluorescent-tagged bacteria were always visualized in the intercellular spaces of the cortex region, and no colonization of the root xylem vessels was detected at any time. To the best of our knowledge, this is the first time this approach has been used to demonstrate endophytism of a biocontrol Pseudomonas spp. strain in a woody host such as olive using a nongnotobiotic system.

Genomic analysis and temperature-dependent transcriptome profiles of the rhizosphere originating strain Pseudomonas aeruginosa M18

PubMed Central

2011-01-01

Background Our previously published reports have described an effective biocontrol agent named Pseudomonas sp. M18 as its 16S rDNA sequence and several regulator genes share homologous sequences with those of P. aeruginosa, but there are several unusual phenotypic features. This study aims to explore its strain specific genomic features and gene expression patterns at different temperatures. Results The complete M18 genome is composed of a single chromosome of 6,327,754 base pairs containing 5684 open reading frames. Seven genomic islands, including two novel prophages and five specific non-phage islands were identified besides the conserved P. aeruginosa core genome. Each prophage contains a putative chitinase coding gene, and the prophage II contains a capB gene encoding a putative cold stress protein. The non-phage genomic islands contain genes responsible for pyoluteorin biosynthesis, environmental substance degradation and type I and III restriction-modification systems. Compared with other P. aeruginosa strains, the fewest number (3) of insertion sequences and the most number (3) of clustered regularly interspaced short palindromic repeats in M18 genome may contribute to the relative genome stability. Although the M18 genome is most closely related to that of P. aeruginosa strain LESB58, the strain M18 is more susceptible to several antimicrobial agents and easier to be erased in a mouse acute lung infection model than the strain LESB58. The whole M18 transcriptomic analysis indicated that 10.6% of the expressed genes are temperature-dependent, with 22 genes up-regulated at 28°C in three non-phage genomic islands and one prophage but none at 37°C. Conclusions The P. aeruginosa strain M18 has evolved its specific genomic structures and temperature dependent expression patterns to meet the requirement of its fitness and competitiveness under selective pressures imposed on the strain in rhizosphere niche. PMID:21884571

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...

Identification and Characterization of Putative Integron-Like Elements of the Heavy-Metal-Hypertolerant Strains of Pseudomonas spp.

PubMed

Ciok, Anna; Adamczuk, Marcin; Bartosik, Dariusz; Dziewit, Lukasz

2016-11-28

Pseudomonas strains isolated from the heavily contaminated Lubin copper mine and Zelazny Most post-flotation waste reservoir in Poland were screened for the presence of integrons. This analysis revealed that two strains carried homologous DNA regions composed of a gene encoding a DNA_BRE_C domain-containing tyrosine recombinase (with no significant sequence similarity to other integrases of integrons) plus a three-component array of putative integron gene cassettes. The predicted gene cassettes encode three putative polypeptides with homology to (i) transmembrane proteins, (ii) GCN5 family acetyltransferases, and (iii) hypothetical proteins of unknown function (homologous proteins are encoded by the gene cassettes of several class 1 integrons). Comparative sequence analyses identified three structural variants of these novel integron-like elements within the sequenced bacterial genomes. Analysis of their distribution revealed that they are found exclusively in strains of the genus Pseudomonas .

Isolation and Molecular Characterization of Novel Chlorpyrifos and 3,5,6-trichloro-2-pyridinol-degrading Bacteria from Sugarcane Farm Soils

PubMed Central

Rayu, Smriti; Nielsen, Uffe N.; Nazaries, Loïc; Singh, Brajesh K.

2017-01-01

Chlorpyrifos (CP) is one of the most widely used organophosphate pesticides in agriculture worldwide, but its extensive use has led to the contamination of various soil and water systems. Microbial bioremediation is considered to be one of the most viable options for the removal of CP from the environment; however, little is known about the soil bacterial diversity that degrade CP. Sequential soil and liquid culture enrichments enabled the isolation of bacterial CP degraders with sequence homologies to Xanthomonas sp., Pseudomonas sp., and Rhizobium sp. The efficacy of the three isolated strains: Xanthomonas sp. 4R3-M1, Pseudomonas sp. 4H1-M3, and Rhizobium sp. 4H1-M1 was further investigated for biodegradation of CP and its primary metabolic product, 3,5,6-trichloro-2-pyridinol (TCP). The results indicate that all three bacterial strains almost completely metabolized CP (10 mg/L) and TCP, occurring as a metabolic degradation product, in mineral salt media as a sole source of carbon and nitrogen. The isolated bacterial strains Xanthomonas sp. 4R3-M1 and Pseudomonas sp. 4H1-M3 could also degrade TCP (10 mg/L) as a sole carbon and nitrogen source, when provided externally. Thus, these bacterial strains may be effective in practical application of bioremediation of both CP and TCP. PMID:28421040

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°.

Degradation of acetaminophen by Delftia tsuruhatensis and Pseudomonas aeruginosa in a membrane bioreactor.

PubMed

De Gusseme, Bart; Vanhaecke, Lynn; Verstraete, Willy; Boon, Nico

2011-02-01

The incidence and fate of pharmaceuticals in the water cycle impose a growing concern for the future reuse of treated water. Because of the recurrent global use of drugs such as Acetaminophen (APAP), an analgesic and antipyretic drug, they are often detected in wastewater treatment plant (WWTP) effluents, receiving surface waters and drinking water resources. In this study, the removal of APAP has been demonstrated in a membrane bioreactor (MBR) fed with APAP as the sole carbon source. After 16 days of operation, at a hydraulic retention time (HRT) of 5 days, more than 99.9% removal was obtained when supplying a synthetic WWTP effluent with 100 μg APAP L(-1). Batch experiments indicated no sorption of APAP to the biomass, no influence of the WWTP effluent matrix, and the capability of the microbial consortium to remove APAP at environmentally relevant concentrations (8.3 μg APAP L(-1)). Incubation with allylthiourea, an ammonia monooxygenase inhibitor, demonstrated that the APAP removal was mainly associated with heterotrophic bacteria and not with the ammonia-oxidizing bacteria. Two APAP degrading strains were isolated from the MBR biomass and identified as Delftia tsuruhatensis and Pseudomonas aeruginosa. During incubation of the isolates, hydroquinone - a potentially toxic transformation product - was temporarily formed but further degraded and/or metabolized. These results suggest that the specific enrichment of a microbial consortium in an MBR operated at a high sludge age might be a promising strategy for post-treatment of WWTP effluents containing pharmaceuticals. © 2010 Elsevier Ltd. All rights reserved.

Characterization of esculin-positive Pseudomonas fluorescens strains isolated from an underground brook.

PubMed

Svec, P; Stegnerová, H; Durnová, E; Sedlácek, I

2004-01-01

A group of sixteen esculin-positive fluorescent pseudomonads isolated from an underground brook flowing through a cave complex was characterized by biotyping, multiple enzyme restriction fragment length polymorphism analysis of 16S rDNA (MERFLP), ribotyping and whole-cell fatty-acid methyl-esters analysis (FAME). All strains were phenotypically close to Pseudomonas fluorescens, but they revealed high biochemical variability as well as some reactions atypical for P. fluorescens species. Because identification of pseudomonads by of biochemical testing is often unclear, further techniques were employed. Fingerprints obtained by MERFLP clearly showed that all strains represent P. fluorescens species. Ribotyping separated the strains analyzed into four groups corresponding almost completely (with the exception of one strain) to the clustering based on biochemical profiles. FAME analysis grouped all the strains into one cluster together with the P. putida (biotype A, B), P. chlororaphis and P. fluorescens biotype F representatives, but differentiated them from other FAME profiles of all pseudomonads included in the standard library TSBA 40 provided by MIDI, Inc.

Biodegradation of nicotine by a newly isolated Pseudomonas stutzeri JZD

NASA Astrophysics Data System (ADS)

Petricevic, Jelena; Gujanicic, Vera; Radic, Danka; Jovicic Petrovic, Jelena; Jovic, Jelena; Raicevic, Vera

2013-04-01

The tobacco-manufacturing process and all activities that use tobacco, produce solid or liquid wastes with high concentrations of nicotine. Nicotine is a significant toxic waste product in tobacco industry. This waste is classified as 'toxic and hazardous' by European Union regulations when the nicotine content exceeds 500 milligrams per kilogram dry weight. Therefore, there is a major environmental requirement to remove nicotine from tobacco wastes. Bioremediation techniques which involve nicotine degradation by microorganisms have attracted attention during the last years, because microorganisms have the potential to reduce nicotine levels in tobacco and to detoxify tobacco wastes. The aim of this study is isolation and identification of nicotine degraded bacteria and optimization of nicotine degradation in laboratory conditions. An aerobic bacterial strain capable of effectively degrading nicotine was isolated from the tobacco industry waste, Serbia. After isolation, the liquid culture was spread onto the solid plates of the nicotine inorganic salt medium using the dilution plate method. Cell morphology of strain was observed by a light microscope and physiological characteristics were determined by Api technique and sequence analyzes of 16S rDNA. This isolate was identified as Pseudomonas stutzeri based on morphology, physiological characteristics, and Apiweb technique. Comparison with sequences available in data library showed the 99% similarity with 16S rDNA gene sequence of the species Pseudomonas stutzeri ( GenBank Acc. No. CP003725). We analyzed the effect of initial nicotine concentration (1g/L, 1.5 g/L, 2.5 g/L) on microbial activity in aim to optimize biodegradation. The effect of cultivation temperature (25°C; 30°C; 37°C) on nicotine degradation by P. stutzeri was evaluated after 24 h of cultivation, with 1.5 g/L nicotine added as the sole carbon source. Effect of biodegradation has depended on initial concentration. During incubation, number of

Strain-Tailored Double-Disk Synergy Test Detects Extended-Spectrum Oxacillinases in Pseudomonas aeruginosa▿

PubMed Central

Hocquet, Didier; Dehecq, Barbara; Bertrand, Xavier; Plésiat, Patrick

2011-01-01

The prevalence of class D extended-spectrum oxacillinases (ES-OXAs) in ceftazidime-resistant strains of Pseudomonas aeruginosa is often underestimated by double-disk synergy tests (DDST) using clavulanate. A DDST with a customized distance between a disk of ceftazidime or cefepime and inhibitors (clavulanate and imipenem) detected 14 out of 15 different ES-OXAs. PMID:21450950

Polycyclic Aromatic Hydrocarbon Degradation of Phytoplankton-Associated Arenibacter spp. and Description of Arenibacter algicola sp. nov., an Aromatic Hydrocarbon-Degrading Bacterium

PubMed Central

Rhodes, Glenn; Mishamandani, Sara; Berry, David; Whitman, William B.; Nichols, Peter D.; Semple, Kirk T.; Aitken, Michael D.

2014-01-01

Pyrosequencing of the bacterial community associated with a cosmopolitan marine diatom during enrichment with crude oil revealed several Arenibacter phylotypes, of which one (OTU-202) had become significantly enriched by the oil. Since members of the genus Arenibacter have not been previously shown to degrade hydrocarbons, we attempted to isolate a representative strain of this genus in order to directly investigate its hydrocarbon-degrading potential. Based on 16S rRNA sequencing, one isolate (designated strain TG409T) exhibited >99% sequence identity to three type strains of this genus. On the basis of phenotypic and genotypic characteristics, strain TG409T represents a novel species in the genus Arenibacter, for which the name Arenibacter algicola sp. nov. is proposed. We reveal for the first time that polycyclic aromatic hydrocarbon (PAH) degradation is a shared phenotype among members of this genus, indicating that it could be used as a taxonomic marker for this genus. Kinetic data for PAH mineralization rates showed that naphthalene was preferred to phenanthrene, and its mineralization was significantly enhanced in the presence of glass wool (a surrogate for diatom cell surfaces). During enrichment on hydrocarbons, strain TG409T emulsified n-tetradecane and crude oil, and cells were found to be preferentially attached to oil droplets, indicating an ability by the strain to express cell surface amphiphilic substances (biosurfactants or bioemulsifiers) as a possible strategy to increase the bioavailability of hydrocarbons. This work adds to our growing knowledge on the diversity of bacterial genera in the ocean contributing to the degradation of oil contaminants and of hydrocarbon-degrading bacteria found living in association with marine eukaryotic phytoplankton. PMID:24212584

Metabolism of waste engine oil by Pseudomonas species.

PubMed

Salam, Lateef B

2016-06-01

Two bacterial strains phylogenetically identified as Pseudomonas aeruginosa strains RM1 and SK1 displayed extensive degradation ability on waste engine oil (SAE 40W) in batch cultures. Spectrophotometric analysis revealed the presence of various heavy metals such as lead, chromium and nickel in the waste engine oil. The rate of degradation of waste engine oil by the isolates, for the first 12 days and the last 9 days were 66.3, 31.6 mg l -1  day -1   and 69.6, 40.0 mg l -1  day -1 for strains RM1 and SK1, respectively. Gas chromatographic (GC) analyses of residual waste engine oil, revealed that 66.58, 89.06 % and 63.40, 90.75 % of the initial concentration of the waste engine oil were degraded by strains RM1 and SK1 within 12 and 21 days. GC fingerprints of the waste engine oil after 12 days of incubation of strains RM1 and SK1 showed total disappearance of C 15 , C 23 , C 24 , C 25 and C 26 hydrocarbon fractions as well as drastic reductions of C 13 , C 14 , C 16 and PAHs fractions such as C 19 -anthracene and C 22 -pyrene. At the end of 21 days incubation, total disappearance of C 17 -pristane, C 22 -pyrene, one of the C 19 -anthracene and significant reduction of C 18 -phytane (97.2 %, strain RM1; 95.1 %, strain SK1) fractions were observed. In addition, <10 % of Day 0 values of medium fraction ranges C 13 , and C 16 were discernible after 21 days. This study has established the potentials of P. aeruginosa strains RM1 and SK1 in the degradation of aliphatic, aromatic and branched alkane components of waste engine oils.

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.

[Characterization of a thermophilic Geobacillus strain DM-2 degrading hydrocarbons].

PubMed

Liu, Qing-kun; Wang, Jun; Li, Guo-qiang; Ma, Ting; Liang, Feng-lai; Liu, Ru-lin

2008-12-01

A thermophilic Geobacillus strain DM-2 from a deep-subsurface oil reservoir was investigated on its capability of degrading crude oil under various conditions as well as its characters on degrading hydrocarbons in optimal conditions. The results showed that Geobacillus strain DM-2 was able to degrade crude oil under anoxic wide-range conditions with pH ranging from 4.0 to 10.0, high temperature in the range of 45-70 degrees C and saline concentration ranging from 0.2% to 3.0%. Furthermore, the optimal temperature and pH value for utilizing hydrocarbons by the strain were 60 degrees C and 7.0, respectively. Under such optimal conditions, the strain utilized liquid paraffine emulsified by itself as its carbon source for growth; further analysis by gas chromatography (GC) and infrared absorption spectroscopy demonstrated that it was able to degrade n-alkanes (C14-C30), branched-chain alkanes and aromatic hydrocarbons in crude oil and could also utilize long-chain n-alkanes from C16 to C36, among of which the degradation efficiency of C28 was the highest, up to 88.95%. One metabolite of the strain oxidizing alkanes is fatty acid.While utilizing C16 as carbon source for 5 d, only one fatty acid-acetic acid was detected by HPLC and MS as the product, with the amount of 0.312 g/L, which indicated that it degraded n-alkanes with pathway of inferior terminal oxidation,and then followed by a beta-oxidation pathway. Due to its characters of efficient emulsification, high-performance degradation of hydrocarbons and fatty-acid production under high temperature and anoxic condition, the strain DM-2 may be potentially applied to oil-waste treatment and microbial enhanced heavy oil recovery in extreme conditions.

Co-biodegradation of anthracene and naphthalene by the bacterium Acinetobacter johnsonii.

PubMed

Jiang, Yan; Qi, Hui; Zhang, Xian M

2018-04-16

NAP (Naphthalene) and ANT (anthracene) usually co-exist in environment and possessed interactional effects on their biodegradation in environment. Presently, a strain of Acinetobacter johnsonii was employed to degrade NAP and ANT in single- and dual-substrate systems. NAP was utilized as prefer substrate by cells to accelerate ANT biodegradation. As much as 200 mg L -1 ANT could be entirely degraded with 1,500 mg L -1 NAP, which was beyond bacterial potential in single substrate system. Especially, the shortest biodegradation period (103 h) for ANT was observed with the presence of 50 mg L -1 NAP. By contrast, ANT showed strong inhibition on NAP degradation, while the peak biodegradation of 1,950 mg L -1 NAP with 50 mg L -1 ANT could still proceed. By introducing an inhibition constant parameter to fit the inhibition on cells, modeling indicated the substrate inhibition for NAP and ANT over the concentrations of 174 and 49 mg L -1 , respectively. Furthermore, enzyme assay revealed the pathway of meta fission in NAP biodegradation due to the appearance of catechol 2,3-dioxygenase activity, and low-level lipase excretion was also found in both NAP and ANT biodegradation, but hardly affect NAP and ANT biodegradation in the present study. To research the interplay of NAP and ANT is conducive to targeted decontamination.

Metalaxyl Degradation by Mucorales Strains Gongronella sp. and Rhizopus oryzae.

PubMed

Martins, Maria Rosário; Santos, Cledir; Pereira, Pablo; Cruz-Morais, Júlio; Lima, Nelson

2017-12-14

In this study, the degradation of metalaxyl was investigated in the presence of two Mucorales strains, previously isolated from soil subjected to repeated treatments with this fungicide and selected after enrichment technique. Fungal strains were characterised by a polyphasic approach using phylogenetic analysis of the Internal Transcribed Spacer (ITS) gene region, phenotypic characterisation by Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) spectral analysis, and growth kinetics experiments. The strains were identified as Gongronella sp. and Rhizopus oryzae . The fungal growth kinetics in liquid cultures containing metalaxyl fits with Haldane model. Under laboratory conditions, the ability of Gongronella sp. and R. oryzae cultures to degrade metalaxyl was evaluated in liquid cultures and soil experiments. Both species were able to: (a) use metalaxyl as the main carbon and energy source; and (b) degrade metalaxyl in polluted soils, with rates around 1.0 mg kg - ¹ d - ¹. This suggests these strains could degrade metalaxyl in soils contaminated with this fungicide.

Isolation of the Autoinducer-Quenching Strain that Inhibits LasR in Pseudomonas aeruginosa

PubMed Central

Weng, Lixing; Zhang, Yuqian; Yang, Yuxiang; Wang, Lianhui

2014-01-01

Quorum sensing (QS) has been recognized as a general phenomenon in microorganisms and plays an important role in many pathogenic bacteria. In this report, we used the Agrobacterium tumefaciens biosensor strain NT1 to rapidly screen for autoinducer-quenching inhibitors from bacteria. After initial screening 5389 isolates obtained from land and beach soil, 53 putative positive strains were identified. A confirmatory bioassay was carried out after concentrating the putative positive culture supernatant, and 22 strains were confirmed to have anti-LasR activity. Finally, we determined the strain JM2, which could completely inhibit biofilm formation of Pseudomonas aeruginosa PAO1, belonged to the genus Pseudomonas by analysis of 16S rDNA. Partially purified inhibitor factor(s) F5 derived from culture supernatants specifically inhibited LasR-controlled elastase and protease in wild type P. aeruginosa PAO1 by 68% and 73%, respectively, without significantly affecting growth; the rhl-controlled pyocyanin and rhamnolipids were inhibited by 54% and 52% in the presence of 100 μg/mL of F5. The swarming motility and biofilm of PAO1 were also inhibited by F5. Real time RT-PCR on samples from 100 μg/mL F5-treated P. aeruginosa showed downregulation of autoinducer synthase (LasRI and rhlI) and cognate receptor (lasR and rhlR) genes by 50%, 28%, 48%, and 29%, respectively. These results provide compelling evidence that the F5 inhibitor(s) interferes with the las system and significantly inhibits biofilm formation. PMID:24736783

Cross-reactive and strain-specific antipeptide antibodies to Pseudomonas aeruginosa PAK and PAO pili.

PubMed Central

Lee, K K; Paranchych, W; Hodges, R S

1990-01-01

Antipeptide antibodies were raised against synthetic peptides corresponding to the amino acid sequences of eight surface predicted regions of the pilin proteins from Pseudomonas aeruginosa PAK and PAO. Four of the anti-PAK peptide antisera cross-reacted with strain PAO pili, while five anti-PAO peptide antisera cross-reacted with strain PAK pili. Only one region of the two pilin proteins (region 88-97) provided strain-specific antibodies when either strain PAK or strain PAO region 88-97 peptides were used to generate antipeptide antibodies. Our results clearly showed that cross-reactive and strain-specific antibodies cannot be based solely on the degree of homology in the aligned protein sequences. The majority of synthetic peptides bound to their homologous antipilus antiserum, suggesting that linear sequences play a significant role in the immunogenic response of native pili. PMID:1974884

Pseudomonas pseudoalcaligenes CECT5344, a cyanide-degrading bacterium with by-product (polyhydroxyalkanoates) formation capacity.

PubMed

Manso Cobos, Isabel; Ibáñez García, María Isabel; de la Peña Moreno, Fernando; Sáez Melero, Lara Paloma; Luque-Almagro, Víctor Manuel; Castillo Rodríguez, Francisco; Roldán Ruiz, María Dolores; Prieto Jiménez, María Auxiliadora; Moreno Vivián, Conrado

2015-06-10

Cyanide is one of the most toxic chemicals produced by anthropogenic activities like mining and jewelry industries, which generate wastewater residues with high concentrations of this compound. Pseudomonas pseudoalcaligenes CECT5344 is a model microorganism to be used in detoxification of industrial wastewaters containing not only free cyanide (CN(-)) but also cyano-derivatives, such as cyanate, nitriles and metal-cyanide complexes. Previous in silico analyses suggested the existence of genes putatively involved in metabolism of short chain length (scl-) and medium chain length (mcl-) polyhydroxyalkanoates (PHAs) located in three different clusters in the genome of this bacterium. PHAs are polyesters considered as an alternative of petroleum-based plastics. Strategies to optimize the bioremediation process in terms of reducing the cost of the production medium are required. In this work, a biological treatment of the jewelry industry cyanide-rich wastewater coupled to PHAs production as by-product has been considered. The functionality of the pha genes from P. pseudoalcaligenes CECT5344 has been demonstrated. Mutant strains defective in each proposed PHA synthases coding genes (Mpha(-), deleted in putative mcl-PHA synthases; Spha(-), deleted in the putative scl-PHA synthase) were generated. The accumulation and monomer composition of scl- or mcl-PHAs in wild type and mutant strains were confirmed by gas chromatography-mass spectrometry (GC-MS). The production of PHAs as by-product while degrading cyanide from the jewelry industry wastewater was analyzed in batch reactor in each strain. The wild type and the mutant strains grew at similar rates when using octanoate as the carbon source and cyanide as the sole nitrogen source. When cyanide was depleted from the medium, both scl-PHAs and mcl-PHAs were detected in the wild-type strain, whereas scl-PHAs or mcl-PHAs were accumulated in Mpha(-) and Spha(-), respectively. The scl-PHAs were identified as homopolymers of 3

Impact of hydrocarbons, PCBs and heavy metals on bacterial communities in Lerma River, Salamanca, Mexico: Investigation of hydrocarbon degradation potential.

PubMed

Brito, Elcia M S; De la Cruz Barrón, Magali; Caretta, César A; Goñi-Urriza, Marisol; Andrade, Leandro H; Cuevas-Rodríguez, Germán; Malm, Olaf; Torres, João P M; Simon, Maryse; Guyoneaud, Remy

2015-07-15

Freshwater contamination usually comes from runoff water or direct wastewater discharges to the environment. This paper presents a case study which reveals the impact of these types of contamination on the sediment bacterial population. A small stretch of Lerma River Basin, heavily impacted by industrial activities and urban wastewater release, was studied. Due to industrial inputs, the sediments are characterized by strong hydrocarbon concentrations, ranging from 2 935 to 28 430μg·kg(-1) of total polyaromatic hydrocarbons (PAHs). These sediments are also impacted by heavy metals (e.g., 9.6μg·kg(-1) of Cd and 246μg·kg(-1) of Cu, about 8 times the maximum recommended values for environmental samples) and polychlorinated biphenyls (ranging from 54 to 123μg·kg(-1) of total PCBs). The bacterial diversity on 6 sediment samples, taken from upstream to downstream of the main industrial and urban contamination sources, was assessed through TRFLP. Even though the high PAH concentrations are hazardous to aquatic life, they are not the only factor driving bacterial community composition in this ecosystem. Urban discharges, leading to hypoxia and low pH, also strongly influenced bacterial community structure. The bacterial bioprospection of these samples, using PAH as unique carbon source, yielded 8 hydrocarbonoclastic strains. By sequencing the 16S rDNA gene, these were identified as similar to Mycobacterium goodii, Pseudomonas aeruginosa, Pseudomonas lundensis or Aeromonas veronii. These strains showed high capacity to degrade naphthalene (between 92 and 100% at 200mg·L(-1)), pyrene (up to 72% at 100mg·L(-1)) and/or fluoranthene (52% at 50mg·L(-1)) as their only carbon source on in vitro experiments. These hydrocarbonoclastic bacteria were detected even in the samples upstream of the city of Salamanca, suggesting chronical contamination, already in place longer before. Such microorganisms are clearly potential candidates for hydrocarbon degradation in the

Induction Specificity and Catabolite Repression of the Early Enzymes in Camphor Degradation by Pseudomonas putida

PubMed Central

Hartline, Richard A.; Gunsalus, I. C.

1971-01-01

The ability of bornane and substituted bornanes to induce the early enzymes for d(+)-camphor degradation and control of these enzymes by catabolite repression were studied in a strain of a Pseudomonas putida. Bornane and 20 substituted bornane compounds showed induction. Of these 21 compounds, bornane and 8 of the substituted bornanes provided induction without supporting growth. Oxygen, but not nitrogen, enhanced the inductive potency of the unsubstituted bornane ring. All bornanedione isomers caused induction, and those with substituents on each of the three consecutive carbon atoms, including the methyl group at the bridgehead carbon, showed induction without supporting growth. Although it was not possible to obtain experimental data for a case of absolute gratuitous induction by compounds not supporting growth, indirect evidence in support of gratuitous induction is presented. It is proposed that the ability of P. putida to tolerate the unusually high degree of possible gratuitous induction observed for camphor catabolism may be related to the infrequent occurrence of bicyclic ring structures in nature. Survival of an organism with a broad specificity for gratuitous induction is discussed. Glucose and succinate, but not glutamate, produced catabolite repression of the early camphor-degrading enzymes. Pathway enzymes differ in their degree of sensitivity to succinate-provoked catabolite repression. The ability of a compound to produce catabolite repression is not, however, directly related to the duration of the lag period (diauxic lag) between growth on camphor and growth on the repressing compound. PMID:5573731

Isolation of a novel amylase and lipase-producing Pseudomonas luteola strain: study of amylase production conditions

PubMed Central

2014-01-01

An amylase and lipase producing bacterium (strain C2) was enriched and isolated from soil regularly contaminated with olive washing wastewater in Sfax, Tunisia. Cell was aerobic, mesophilic, Gram-negative, motile, non-sporulating bacterium, capable of growing optimally at pH 7 and 30°C and tolerated maximally 10% (W/V) NaCl. The predominant fatty acids were found to be C18:1ω7c (32.8%), C16:1ω7c (27.3%) and C16:0 (23.1%). Phylogenetic analysis of the 16S rRNA gene revealed that this strain belonging to the genus Pseudomonas. Strain C2 was found to be closely related to Pseudomonas luteola with more than 99% of similarity. Amylase optimization extraction was carried out using Box Behnken Design (BBD). Its maximal activity was found when the pH and temperature ranged from 5.5 to 6.5 and from 33 to 37°C, respectively. Under these conditions, amylase activity was found to be about 9.48 U/ml. PMID:24405763

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.

Complete Genome Sequence of the p-Nitrophenol-Degrading Bacterium Pseudomonas putida DLL-E4

PubMed Central

Hu, Xiaojun; Wang, Jue; Wang, Fei; Chen, Qiongzhen; Huang, Yan

2014-01-01

The first complete genome sequence of a p-nitrophenol (PNP)-degrading bacterium is reported here. Pseudomonas putida DLL-E4, a Gram-negative bacterium isolated from methyl-parathion-polluted soil, can utilize PNP as the sole carbon and nitrogen source. P. putida DLL-E4 has a 6,484,062 bp circular chromosome that contains 5,894 genes, with a G+C content of 62.46%. PMID:24948765

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.

Abundance of Dioxygenase Genes Similar to Ralstonia sp. Strain U2 nagAc Is Correlated with Naphthalene Concentrations in Coal Tar-Contaminated Freshwater Sediments

PubMed Central

Dionisi, Hebe M.; Chewning, Christopher S.; Morgan, Katherine H.; Menn, Fu-Min; Easter, James P.; Sayler, Gary S.

2004-01-01

We designed a real-time PCR assay able to recognize dioxygenase large-subunit gene sequences with more than 90% similarity to the Ralstonia sp. strain U2 nagAc gene (nagAc-like gene sequences) in order to study the importance of organisms carrying these genes in the biodegradation of naphthalene. Sequencing of PCR products indicated that this real-time PCR assay was specific and able to detect a variety of nagAc-like gene sequences. One to 100 ng of contaminated-sediment total DNA in 25-μl reaction mixtures produced an amplification efficiency of 0.97 without evident PCR inhibition. The assay was applied to surficial freshwater sediment samples obtained in or in close proximity to a coal tar-contaminated Superfund site. Naphthalene concentrations in the analyzed samples varied between 0.18 and 106 mg/kg of dry weight sediment. The assay for nagAc-like sequences indicated the presence of (4.1 ± 0.7) × 103 to (2.9 ± 0.3) × 105 copies of nagAc-like dioxygenase genes per μg of DNA extracted from sediment samples. These values corresponded to (1.2 ± 0.6) × 105 to (5.4 ± 0.4) × 107 copies of this target per g of dry weight sediment when losses of DNA during extraction were taken into account. There was a positive correlation between naphthalene concentrations and nagAc-like gene copies per microgram of DNA (r = 0.89) and per gram of dry weight sediment (r = 0.77). These results provide evidence of the ecological significance of organisms carrying nagAc-like genes in the biodegradation of naphthalene. PMID:15240274

Endosulfan Degradation by Selected Strains of Plant Growth Promoting Rhizobacteria.

PubMed

Rani, Rupa; Kumar, Vipin

2017-07-01

Sixty endosulfan tolerant bacterial strains were isolated from pesticide stressed agricultural soils. Five most tolerant strains were tested for plant growth promoting (PGP) activities and endosulfan degradation under different optimizing conditions in broth and soil. The strains PRB101 and PRB77 were the most efficient in terms of endosulfan degradation and PGP activities and showed solubilization indexes of 3.3 and 3.1 mm, indole acetic acid production of 71 and 68 μg mL -1 , siderophore zones of 13 mm each at the recommended dosage, respectively. Hydrogen cyanide and ammonia production remained unaffected in the presence of endosulfan. PRB101 and PRB77 strains were able to degrade 74% and 70% of endosulfan in broth and 67% and 63% in soil, respectively. Based on 16S rDNA analysis, the strains PRB101 and PRB77 exhibited 99% homology with Bacillus sp. KF984414 and Bacillus sp. LN849696, respectively.

Aerobic biodegradation of N-nitrosodimethylamine (NDMA) by axenic bacterial strains.

PubMed

Sharp, Jonathan O; Wood, Thomas K; Alvarez-Cohen, Lisa

2005-03-05

The water contaminant N-nitrosodimethylamine (NDMA) is a probable human carcinogen whose appearance in the environment is related to the release of rocket fuel and to chlorine-based disinfection of water and wastewater. Although this compound has been shown to be biodegradable, there is minimal information about the organisms capable of this degradation, and little is understood of the mechanisms or biochemistry involved. This study shows that bacteria expressing monooxygenase enzymes functionally similar to those demonstrated to degrade NDMA in eukaryotes have the capability to degrade NDMA. Specifically, induction of the soluble methane monooxygenase (sMMO) expressed by Methylosinus trichosporium OB3b, the propane monooxygenase (PMO) enzyme of Mycobacterium vaccae JOB-5, and the toluene 4-monooxygenases found in Ralstonia pickettii PKO1 and Pseudomonas mendocina KR1 resulted in NDMA degradation by these strains. In each of these cases, brief exposure to acetylene gas, a suicide substrate for certain monooxygenases, inhibited the degradation of NDMA. Further, Escherichia coli TG1/pBS(Kan) containing recombinant plasmids derived from the toluene monooxygenases found in strains PKO1 and KR1 mimicked the behavior of the parent strains. In contrast, M. trichosporium OB3b expressing the particulate form of MMO, Burkholderia cepacia G4 expressing the toluene 2-monooxygenase, and Pseudomonas putida mt-2 expressing the toluene sidechain monooxygenase were not capable of NDMA degradation. In addition, bacteria expressing aromatic dioxygenases were not capable of NDMA degradation. Finally, Rhodococcus sp. RR1 exhibited the ability to degrade NDMA by an unidentified, constitutively expressed enzyme that, unlike the confirmed monooxygenases, was not inhibited by acetylene exposure. 2005 Wiley Periodicals, Inc.

Synthesis, Spectral Characterization, In-vitro Antibacterial and Antifungal Activities of Novel (2e)-Ethyl-2-(2-(2, 4-Dinitrophenyl) Hydrazono)-4-(Naphthalen-2-yl)-6-Arylcyclohex-3-Enecarboxylates

PubMed Central

Kanagarajan, V; Thanusu, J; Gopalakrishnan, M

2011-01-01

In a search for new leads towards potent antimicrobial agents, an array of novel (2E)-ethyl-2-(2-(2,4-dinitrophenyl)hydrazono)-4-(naphthalen-2-yl)-6-arylcyclohex-3-ene carboxylates 17-24 were synthesized and characterized through their melting point, elemental analysis, MS, FT-IR, one-dimensional NMR (1H, D2O exchanged 1H and 13C), two dimensional HOMOCOR and HSQC spectroscopic data. In-vitro microbiological evaluations were carried out for all the newly synthesized compounds 17-24 against clinically isolated bacterial strains namely Salmonella typhii, Klebsiellapneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, β-Hemolytic streptococcus and Micrococcus luteusand also fungal strains namely Aspergillusflavus, Aspergillusniger, Mucor, Rhizopus and Microsporumgypseumand finally, the results of their structure activity relationship were discussed. The obtained results can be used as the key step for the building of novel chemical compounds with interesting antimicrobial profiles comparable to that of the standard drugs. PMID:24250406

Synthesis, Spectral Characterization, In-vitro Antibacterial and Antifungal Activities of Novel (2e)-Ethyl-2-(2-(2, 4-Dinitrophenyl) Hydrazono)-4-(Naphthalen-2-yl)-6-Arylcyclohex-3-Enecarboxylates.

PubMed

Kanagarajan, V; Thanusu, J; Gopalakrishnan, M

2011-01-01

In a search for new leads towards potent antimicrobial agents, an array of novel (2E)-ethyl-2-(2-(2,4-dinitrophenyl)hydrazono)-4-(naphthalen-2-yl)-6-arylcyclohex-3-ene carboxylates 17-24 were synthesized and characterized through their melting point, elemental analysis, MS, FT-IR, one-dimensional NMR ((1)H, D2O exchanged (1)H and (13)C), two dimensional HOMOCOR and HSQC spectroscopic data. In-vitro microbiological evaluations were carried out for all the newly synthesized compounds 17-24 against clinically isolated bacterial strains namely Salmonella typhii, Klebsiellapneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, β-Hemolytic streptococcus and Micrococcus luteusand also fungal strains namely Aspergillusflavus, Aspergillusniger, Mucor, Rhizopus and Microsporumgypseumand finally, the results of their structure activity relationship were discussed. The obtained results can be used as the key step for the building of novel chemical compounds with interesting antimicrobial profiles comparable to that of the standard drugs.

Degradation of the herbicide paraquat by macromycetes isolated from southeastern Mexico.

PubMed

Camacho-Morales, Reyna L; Guillén-Navarro, Karina; Sánchez, José E

2017-10-01

Fifty-four macromycetes, isolated from southeastern Mexico, were used in order to evaluate their capacity for degradation and tolerance to the herbicide paraquat. Ten of these strains were capable of growing in a solid culture medium in the presence of 200 ppm paraquat. Subsequently, assays to evaluate the degradation of the xenobiotic in a liquid medium were carried out. Of the ten strains evaluated, three presented the highest levels of degradation of the compound, which were Trametes pavonia (54.2%), Trametes versicolor (54.1%) and Hypholoma dispersum. They presented the highest overall degradation percentage (70.7%) after 12 days culture. The presence of ligninolytic enzymes in these strains was evaluated. H. dispersum only presented aryl alcohol oxidase activity; however, with the data obtained, it was not possible to conclude whether this specific enzyme is responsible for paraquat degradation. The level of degradation obtained is above the one reported for Pseudomonas putida , one of the few reports on paraquat degradation. This is the first report on the contaminant degradation capacity of H. dispersum .

Development of novel assays for lignin degradation: comparative analysis of bacterial and fungal lignin degraders.

PubMed

Ahmad, Mark; Taylor, Charles R; Pink, David; Burton, Kerry; Eastwood, Daniel; Bending, Gary D; Bugg, Timothy D H

2010-05-01

Two spectrophotometric assays have been developed to monitor breakdown of the lignin component of plant lignocellulose: a continuous fluorescent assay involving fluorescently modified lignin, and a UV-vis assay involving chemically nitrated lignin. These assays have been used to analyse lignin degradation activity in bacterial and fungal lignin degraders, and to identify additional soil bacteria that show activity for lignin degradation. Two soil bacteria known to act as aromatic degraders, Pseudomonas putida and Rhodococcus sp. RHA1, consistently showed activity in these assays, and these strains were shown in a small scale experiment to breakdown lignocellulose, producing a number of monocyclic phenolic products. Using milled wood lignin prepared from wheat straw, pine, and miscanthus, some bacterial lignin degraders were found to show specificity for lignin type. These assays could be used to identify novel lignin degraders for breakdown of plant lignocellulose.

Isolation of an isocarbophos-degrading strain of Arthrobacter sp. scl-2 and identification of the degradation pathway.

PubMed

Rong, Li; Guo, Xinqiang; Chen, Kai; Zhu, Jianchun; Li, Shunpeng; Jiang, Jiandong

2009-11-01

Isocarbophos is a widely used organophosphorus insecticide that has caused environmental pollution in many areas. However, degradation of isocarbophos by pure cultures has not been extensively studied, and the degradation pathway has not been determined. In this paper, a highly effective isocarbophos-degrading strain, scl-2, was isolated from isocarbophos-polluted soil. Strain scl-2 was preliminarily identified as Arthrobacter sp. based on its morphological, physiological, and biochemical properties, as well as 16S rDNA analysis. Strain scl-2 could utilize isocarbophos as its sole source of carbon and phosphorus for growth. One hundred mg/l isocarbophos could be degraded to a nondetectable level in 18 h by scl-2 in cell culture, and isofenphos-methyl, profenofos, and phosmet could also be degraded. During the degradation of isocarbophos, the metabolites isopropyl salicylate, salicylate, and gentisate were detected and identified based on MS/MS analysis and their retention times in HPLC. Transformation of gentisate to pyruvate and fumarate via maleylpyruvate and fumarylpyruvate was detected by assaying for the activities of gentisate 1,2- dioxygenase (GDO) and maleylpyruvate isomerase. Therefore, we have identified the degradation pathway of isocarbophos in Arthrobacter sp. scl-2 for the first time. This study highlights an important potential use of the strain scl-2 for the cleanup of environmental contamination by isocarbophos and presents a mechanism of isocarbophos metabolism.

Regiospecific and stereoselective hydroxylation of 1-indanone and 2-indanone by naphthalene dioxygenase and toluene dioxygenase.

PubMed Central

Resnick, S M; Torok, D S; Lee, K; Brand, J M; Gibson, D T

1994-01-01

The biotransformation of 1-indanone and 2-indanone to hydroxyindanones was examined with bacterial strains expressing naphthalene dioxygenase (NDO) and toluene dioxygenase (TDO) as well as with purified enzyme components. Pseudomonas sp. strain 9816/11 cells, expressing NDO, oxidized 1-indanone to a mixture of 3-hydroxy-1-indanone (91%) and 2-hydroxy-1-indanone (9%). The (R)-3-hydroxy-1-indanone was formed in 62% enantiomeric excess (ee) (R:S, 81:19), while the 2-hydroxy-1-indanone was racemic. The same cells also formed 2-hydroxy-1-indanone from 2-indanone. Purified NDO components oxidized 1-indanone and 2-indanone to the same products produced by strain 9816/11. P. putida F39/D cells, expressing TDO, oxidized 2-indanone to (S)-2-hydroxy-1-indanone of 76% ee (R:S, 12:88) but did not oxidize 1-indanone efficiently. Purified TDO components also oxidized 2-indanone to (S)-2-hydroxy-1-indanone of 90% ee (R:S, 5:95) and failed to oxidize 1-indanone. Oxidation of 1- and 2-indanone in the presence of [18O]oxygen indicated that the hydroxyindanones were formed by the incorporation of a single atom of molecular oxygen (monooxygenation) rather than by the dioxygenation of enol tautomers of the ketone substrates. As alternatives to chemical synthesis, these biotransformations represent direct routes to 3-hydroxy-1-indanone and 2-hydroxy-1-indanone as the major products from 1-indanone and 2-indanone, respectively. PMID:7944365

Regiospecific and stereoselective hydroxylation of 1-indanone and 2-indanone by naphthalene dioxygenase and toluene dioxygenase.

PubMed

Resnick, S M; Torok, D S; Lee, K; Brand, J M; Gibson, D T

1994-09-01

The biotransformation of 1-indanone and 2-indanone to hydroxyindanones was examined with bacterial strains expressing naphthalene dioxygenase (NDO) and toluene dioxygenase (TDO) as well as with purified enzyme components. Pseudomonas sp. strain 9816/11 cells, expressing NDO, oxidized 1-indanone to a mixture of 3-hydroxy-1-indanone (91%) and 2-hydroxy-1-indanone (9%). The (R)-3-hydroxy-1-indanone was formed in 62% enantiomeric excess (ee) (R:S, 81:19), while the 2-hydroxy-1-indanone was racemic. The same cells also formed 2-hydroxy-1-indanone from 2-indanone. Purified NDO components oxidized 1-indanone and 2-indanone to the same products produced by strain 9816/11. P. putida F39/D cells, expressing TDO, oxidized 2-indanone to (S)-2-hydroxy-1-indanone of 76% ee (R:S, 12:88) but did not oxidize 1-indanone efficiently. Purified TDO components also oxidized 2-indanone to (S)-2-hydroxy-1-indanone of 90% ee (R:S, 5:95) and failed to oxidize 1-indanone. Oxidation of 1- and 2-indanone in the presence of [18O]oxygen indicated that the hydroxyindanones were formed by the incorporation of a single atom of molecular oxygen (monooxygenation) rather than by the dioxygenation of enol tautomers of the ketone substrates. As alternatives to chemical synthesis, these biotransformations represent direct routes to 3-hydroxy-1-indanone and 2-hydroxy-1-indanone as the major products from 1-indanone and 2-indanone, respectively.

The clc Element of Pseudomonas sp. Strain B13, a Genomic Island with Various Catabolic Properties

PubMed Central

Gaillard, Muriel; Vallaeys, Tatiana; Vorhölter, Frank Jörg; Minoia, Marco; Werlen, Christoph; Sentchilo, Vladimir; Pühler, Alfred; van der Meer, Jan Roelof

2006-01-01

Pseudomonas sp. strain B13 is a bacterium known to degrade chloroaromatic compounds. The properties to use 3- and 4-chlorocatechol are determined by a self-transferable DNA element, the clc element, which normally resides at two locations in the cell's chromosome. Here we report the complete nucleotide sequence of the clc element, demonstrating the unique catabolic properties while showing its relatedness to genomic islands and integrative and conjugative elements rather than to other known catabolic plasmids. As far as catabolic functions, the clc element harbored, in addition to the genes for chlorocatechol degradation, a complete functional operon for 2-aminophenol degradation and genes for a putative aromatic compound transport protein and for a multicomponent aromatic ring dioxygenase similar to anthranilate hydroxylase. The genes for catabolic functions were inducible under various conditions, suggesting a network of catabolic pathway induction. For about half of the open reading frames (ORFs) on the clc element, no clear functional prediction could be given, although some indications were found for functions that were similar to plasmid conjugation. The region in which these ORFs were situated displayed a high overall conservation of nucleotide sequence and gene order to genomic regions in other recently completed bacterial genomes or to other genomic islands. Most notably, except for two discrete regions, the clc element was almost 100% identical over the whole length to a chromosomal region in Burkholderia xenovorans LB400. This indicates the dynamic evolution of this type of element and the continued transition between elements with a more pathogenic character and those with catabolic properties. PMID:16484212

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.

Isolation and characterization of diuron-degrading bacteria from lotic surface water.

PubMed

Batisson, Isabelle; Pesce, Stéphane; Besse-Hoggan, Pascale; Sancelme, Martine; Bohatier, Jacques

2007-11-01

The bacterial community structure of a diuron-degrading enrichment culture from lotic surface water samples was analyzed and the diuron-degrading strains were selected using a series of techniques combining temporal temperature gradient gel electrophoresis (TTGE) of 16 S rDNA gene V1-V3 variable regions, isolation of strains on agar plates, colony hybridization methods, and biodegradation assays. The TTGE fingerprints revealed that diuron had a strong impact on bacterial community structure and highlighted both diuron-sensitive and diuron-adapted bacterial strains. Two bacterial strains, designated IB78 and IB93 and identified as belonging to Pseudomonas sp. and Stenotrophomonas sp., were isolated and shown to degrade diuron in pure resting cells in a first-order kinetic reaction during the first 24 h of incubation with no 3,4-DCA detected. The percentages of degradation varied from 25% to 60% for IB78 and 20% to 65% for IB93 and for a diuron concentration range from 20 mg/L to 2 mg/L, respectively. It is interesting to note that diuron was less degraded by single isolates than by mixed resting cells, thereby underlining a cumulative effect between these two strains. To the best of our knowledge, this is the first report of diuron-degrading strains isolated from lotic surface water.

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

PubMed

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

2005-11-01

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

Anaerobic Degradation of Benzene and Polycyclic Aromatic Hydrocarbons.

PubMed

Meckenstock, Rainer U; Boll, Matthias; Mouttaki, Housna; Koelschbach, Janina S; Cunha Tarouco, Paola; Weyrauch, Philip; Dong, Xiyang; Himmelberg, Anne M

2016-01-01

Aromatic hydrocarbons such as benzene and polycyclic aromatic hydrocarbons (PAHs) are very slowly degraded without molecular oxygen. Here, we review the recent advances in the elucidation of the first known degradation pathways of these environmental hazards. Anaerobic degradation of benzene and PAHs has been successfully documented in the environment by metabolite analysis, compound-specific isotope analysis and microcosm studies. Subsequently, also enrichments and pure cultures were obtained that anaerobically degrade benzene, naphthalene or methylnaphthalene, and even phenanthrene, the largest PAH currently known to be degradable under anoxic conditions. Although such cultures grow very slowly, with doubling times of around 2 weeks, and produce only very little biomass in batch cultures, successful proteogenomic, transcriptomic and biochemical studies revealed novel degradation pathways with exciting biochemical reactions such as for example the carboxylation of naphthalene or the ATP-independent reduction of naphthoyl-coenzyme A. The elucidation of the first anaerobic degradation pathways of naphthalene and methylnaphthalene at the genetic and biochemical level now opens the door to studying the anaerobic metabolism and ecology of anaerobic PAH degraders. This will contribute to assessing the fate of one of the most important contaminant classes in anoxic sediments and aquifers. © 2016 S. Karger AG, Basel.

Isolation of nitrite-degrading strains from Douchi and their application to degrade high nitrite in Jiangshui.

PubMed

Guo, Xing; Liu, Bianfang; Gao, Lina; Zhou, Yuan; Shan, Yuanyuan; Lü, Xin

2018-06-01

Excessive nitrite in food is potentially harmful to human health because of its carcinogenic effects caused by nitroso-dervivatives. Douchi, which widely distributed throughout the country, is a traditional solid fermented soybean food with low nitrite content. In this study, bacterias which can degrade nitrite were isolated from Douchi and identified according to 16S rDNA sequence. Acinetobacter guillouiae, Acinetobacter bereziniae, Bacillus subtilis, Bacillus tequilensis, Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus aryabhattai and Bacillus methylotrophicus were selected. It was shown that all strains have nitrite degradation capability, in which 99.41 % nitrite can be degraded by Bacillus subtilis NDS1. The enzyme activities of these strains were determined at 24 h and 48 h, which corresponded to their nitrite degradation rates. The strains were firstly tried to inoculate in Jiangshui, which is a kind of traditional fermented vegetable in northwest China and often has high nitrite content. It was found that Bacillus subtilis NDS1, Bacillus tequilensis NDS3, Acinetobacter bereziniae NDS4, Bacillus subtilis NDS6, Bacillus subtilis NDS12 can degrade nitrite in Jiangshui more quickly, among which Acinetobacter bereziniae NDS4 degraded almost all nitrite in 48 h while it took 180 h for control. These results indicated that the selected strains have potential to become nitrite degradition agent in food. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Cometabolic degradation kinetics of TCE and phenol by Pseudomonas putida.

PubMed

Chen, Yan-Min; Lin, Tsair-Fuh; Huang, Chih; Lin, Jui-Che

2008-08-01

Modeling of cometabolic kinetics is important for better understanding of degradation reaction and in situ application of bio-remediation. In this study, a model incorporated cell growth and decay, loss of transformation activity, competitive inhibition between growth substrate and non-growth substrate and self-inhibition of non-growth substrate was proposed to simulate the degradation kinetics of phenol and trichloroethylene (TCE) by Pseudomonas putida. All the intrinsic parameters employed in this study were measured independently, and were then used for predicting the batch experimental data. The model predictions conformed well to the observed data at different phenol and TCE concentrations. At low TCE concentrations (<2 mg l(-1)), the models with or without self-inhibition of non-growth substrate both simulated the experimental data well. However, at higher TCE concentrations (>6 mg l(-1)), only the model considering self-inhibition can describe the experimental data, suggesting that a self-inhibition of TCE was present in the system. The proposed model was also employed in predicting the experimental data conducted in a repeated batch reactor, and good agreements were observed between model predictions and experimental data. The results also indicated that the biomass loss in the degradation of TCE below 2 mg l(-1) can be totally recovered in the absence of TCE for the next cycle, and it could be used for the next batch experiment for the degradation of phenol and TCE. However, for higher concentration of TCE (>6 mg l(-1)), the recovery of biomass may not be as good as that at lower TCE concentrations.

Whole genome analysis of six organophosphate-degrading rhizobacteria reveals putative agrochemical degradation enzymes with broad substrate specificity.

PubMed

Iyer, Rupa; Iken, Brian; Damania, Ashish; Krieger, Jerry

2018-05-01

Six organophosphate-degrading bacterial strains collected from farm and ranch soil rhizospheres across the Houston-metropolitan area were identified as strains of Pseudomonas putida (CBF10-2), Pseudomonas stutzeri (ODKF13), Ochrobactrum anthropi (FRAF13), Stenotrophomonas maltophilia (CBF10-1), Achromobacter xylosoxidans (ADAF13), and Rhizobium radiobacter (GHKF11). Whole genome sequencing data was assessed for relevant genes, proteins, and pathways involved in the breakdown of agrochemicals. For comparative purposes, this analysis was expanded to also include data from deposited strains in the National Center for Biotechnology Information's (NCBI) database. This study revealed Zn-dependent metallo-β-lactamase (MBL)-fold proteins similar to OPHC2 first identified in P. pseudoalcaligenes as the likely agents of organophosphate (OP) hydrolysis in A. xylosoxidans ADAF13, S. maltophilia CBF10-1, O. anthropi FRAF13, and R. radiobacter GHKF11. A search of similar proteins within NCBI identified over 200 hits for bacterial genera and species with a similar OPHC2 domain. Taken together, we conclude from this data that intrinsic low-level OP hydrolytic activity is likely prevalent across the rhizosphere stemming from widespread OPHC2-like metalloenzymes. In addition, P. stutzeri ODKF13, P. putida CBF10-2, O. anthropi FRAF13, and R. radiobacter GHKF11 were found to harbor glycine oxidase (GO) enzymes that putatively possess low-level activity against the herbicide glyphosate. These bacterial GOs are reported to catalyze the degradation of glyphosate to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and suggest a possible link to AMPA that can be found in glyphosate-contaminated agricultural soil. The presence of aromatic degradation proteins were also detected in five of six study strains, but are attributed primarily to components of the widely distributed β-ketoadipate pathway found in many soil bacteria.

Secondary Organic Aerosol Formation from the Photooxidation of Naphthalene

NASA Astrophysics Data System (ADS)

Zhou, S.; Chen, Y.; Wenger, J.

2009-04-01

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous air pollutants that are released into the atmosphere as a by-product of combustion processes. The gas-phase PAHs can be chemically transformed via reaction with the hydroxyl radical to produce a range of oxidised organic compounds and other pollutants such as ozone and secondary organic aerosol (SOA). Epidemiological studies have established that exposure to this type of air pollution is associated with damaging effects on the respiratory and cardiovascular systems, and can lead to asthma, oxidative stress, health deterioration and even death. The major anthropogenic source of SOA in urban areas is believed to be aromatic hydrocarbons, which are present in automobile fuels and are used as solvents. As a result, research is currently being performed on the characterisation of SOA produced from aromatic hydrocarbons such as toluene, the xylenes and trimethylbenzenes. However, significant amounts of PAHs are also released into urban areas from automobile emissions and the combustion of fossil fuels for home heating. Naphthalene is regularly cited as the most abundant PAH in polluted urban air, with typical ambient air concentrations of 0.05 - 0.20 parts per billion (ppbV) in European cities, comparable to the xylenes. Since naphthalene reacts in an analogous manner to monocyclic aromatic compounds then it is also expected to make a significant contribution to ambient SOA. However, the yield and chemical composition of SOA produced from the atmospheric degradation of naphthalene is not well known. In this presentation, the effects of NOx level and relative humidity on the SOA formation from the phootooixdation of naphthalene will be presented. A series of experiments has been performed in a large atmospheric simulation chamber equipped with a gas chromatograph and analyzers for monitoring nitrogen oxides (NOx) and ozone. SOA formation from the photooxidation of naphthalene was measured using a scanning mobility

Biosynthesis of Pyocyanine by a Paraffin Hydrocarbon-oxidizing Strain of Pseudomonas aeruginosa

PubMed Central

Lee, E. G.-H.; Walden, C. C.

1969-01-01

A paraffin-oxidizing bacterium, designated as Pseudomonas aeruginosa ATS-14, was isolated from soil samples obtained from the Athabasca “tar sands.” This strain utilized kerosene as the only carbon source of energy and produced a high concentration of pyocyanine in the culture medium. Aromatic carbons were not attacked, but C10 to C17n-alkanes were readily oxidized by the pseudomonad and formed pyocyanine. The highest yield of the pigment was obtained from hexadecane and heptadecane. PMID:4977219

Strains of Pseudomonas syringae pv. syringae from pea are phylogenetically and pathogenically diverse.

PubMed

Martín-Sanz, Alberto; de la Vega, Marcelino Pérez; Murillo, Jesús; Caminero, Constantino

2013-07-01

Pseudomonas syringae pv. syringae causes extensive yield losses in the pea crop worldwide, although there is little information on its host specialization and its interactions with pea. A collection of 88 putative P. syringae pv. syringae strains (including 39 strains isolated from pea) was characterized by repetitive polymerase chain reaction (rep-PCR), multilocus sequence typing (MLST), and syrB amplification and evaluated for pathogenicity and virulence. rep-PCR data grouped the strains from pea into two groups (1B and 1C) together with strains from other hosts; a third group (1A) was formed exclusively with strains isolated from non-legume species. MLST data included all strains from pea in the genomospecies 1 of P. syringae pathovars defined in previous studies; they were distributed in the same three groups defined by rep-PCR. The inoculations performed in two pea cultivars showed that P. syringae pv. syringae strains from groups 1A and 1C were less virulent than strains from group 1B, suggesting a possible pathogenic specialization in this group. This study shows the existence of genetically and pathogenically distinct P. syringae pv. syringae strain groups from pea, which will be useful for the diagnostic and epidemiology of this pathogen and for disease resistance breeding.

40 CFR 704.43 - Chlorinated naphthalenes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Chlorinated naphthalenes. 704.43... § 704.43 Chlorinated naphthalenes. (a) Definitions. (1) Extent of chlorination means the percent by... means the relative amounts of each isomeric chlorinated naphthalene that composes the chemical substance...

40 CFR 704.43 - Chlorinated naphthalenes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Chlorinated naphthalenes. 704.43... § 704.43 Chlorinated naphthalenes. (a) Definitions. (1) Extent of chlorination means the percent by... means the relative amounts of each isomeric chlorinated naphthalene that composes the chemical substance...

Naphthalene distributions and human exposure in Southern California

NASA Astrophysics Data System (ADS)

Lu, Rong; Wu, Jun; Turco, Richard P.; Winer, Arthur M.; Atkinson, Roger; Arey, Janet; Paulson, Suzanne E.; Lurmann, Fred W.; Miguel, Antonio H.; Eiguren-Fernandez, Arantzazu

The regional distribution of, and human exposure to, naphthalene are investigated for Southern California. A comprehensive approach is taken in which advanced models are linked for the first time to quantify population exposure to the emissions of naphthalene throughout Southern California. Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons found in polluted urban environments, and has been detected in both outdoor and indoor air samples. Exposure to high concentrations of naphthalene may have adverse health effects, possibly causing cancer in humans. Among the significant emission sources are volatilization from naphthalene-containing products, petroleum refining, and combustion of fossil fuels and wood. Gasoline and diesel engine exhaust, with related vaporization from fuels, are found to contribute roughly half of the daily total naphthalene burden in Southern California. As part of this study, the emission inventory for naphthalene has been verified against new field measurements of the naphthalene-to-benzene ratio in a busy traffic tunnel in Los Angeles, supporting the modeling work carried out here. The Surface Meteorology and Ozone Generation (SMOG) airshed model is used to compute the spatial and temporal distributions of naphthalene and its photooxidation products in Southern California. The present simulations reveal a high degree of spatial variability in the concentrations of naphthalene-related species, with large diurnal and seasonal variations as well. Peak naphthalene concentrations are estimated to occur in the early morning hours in the winter season. The naphthalene concentration estimates obtained from the SMOG model are employed in the Regional Human Exposure (REHEX) model to calculate population exposure statistics. Results show average hourly naphthalene exposures in Southern California under summer and winter conditions of 270 and 430 ng m -3, respectively. Exposure to significantly higher concentrations

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

Camphor Plasmid-Mediated Chromosomal Transfer in Pseudomonas putida

PubMed Central

Shaham, M.; Chakrabarty, A. M.; Gunsalus, I. C.

1973-01-01

Camphor-utilizing strains of Pseudomonas putida have been shown to carry the genetic information required for camphor degradation on a plasmid. The plasmid-carrying strains can serve as donors of both plasmid-borne and chromosomal genes. As recipients, plasmid-deleted strains are much superior to those carrying the camphor pathway genes. The transfer frequency of chromosomal, but not plasmid-borne, genes is markedly enhanced if the donor cells are irradiated with ultraviolet light followed by 3-h of growth on a rich medium in the dark. Recombinants selected for prototrophy are stable and most acquire the camphor (CAM) plasmid concomitantly; only a few of the Cam+ recombinants inherit the donor's ability to transfer chromosomal genes at a high frequency. Transfer-defective mutations occur on the CAM plasmid, affecting both CAM and chromosomal gene transfer. PMID:4745436

Products from the incomplete metabolism of pyrene by polycyclic aromatic hydrocarbon-degrading bacteria

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

Kazunga, C.; Aitken, M.D.

Pyrene is a regulated pollutant at sites contaminated with polycyclic aromatic hydrocarbons (PAH). It is mineralized by some bacteria but is also transformed to nonmineral products by a variety of other PAH-degrading bacteria. The authors examined the formation of such products by four bacterial strains and identified and further characterized the most apparently significant of these metabolites. Pseudomonas stutzeri strain P16 and Bacillus cereus strain P21 transformed pyrene primarily to cis-4,5-dihydro-4,5-dihydroxypyrene (PYRdHD), the first intermediate in the known pathway for aerobic bacterial mineralization of pyrene. Sphingomonas yanoikuyae strain R1 transformed pyrene to PYRdHD and pyrene-4,5-dione (PYRQ). Both strain R1 andmore » Pseudomonas saccharophila strain P15 transform PYRdHD to PYRQ nearly stoichiometrically, suggesting that PYRQ is formed by oxidation of PYRdHD to 4,5-dihydroxypyrene and subsequent autoxidation of this metabolite. A pyrene-mineralizing organism, Mycobacterium strain PYR-1, also transforms PYRdHD to PYRQ at high initial concentrations of PYRdHD. However, strain PYR-1 is able to use both PYRdHD and PYRQ as growth substrates. PYRdHD strongly inhibited phenanthrene degradation by strains P15 and R1 but had only a minor effect on strains P16 and P21. At their aqueous saturation concentrations, both PYRdHD and PYRQ severely inhibited benzo[a]pyrene mineralization by strains P15 and R1. Collectively, these findings suggest that products derived from pyrene transformation have the potential to accumulate in PAH-contaminated systems and that such products can significantly influence the removal of other PAH. However, these products may be susceptible to subsequent degradation by organisms able to metabolize pyrene more extensively if such organisms are present in the system.« less

Microbial flora analysis for the degradation of beta-cypermethrin.

PubMed

Qi, Zhang; Wei, Zhang

2017-03-01

In the Xinjiang region of Eurasia, sustained long-term and continuous cropping of cotton over a wide expanse of land is practiced, which requires application of high levels of pyrethroid and other classes of pesticides-resulting in high levels of pesticide residues in the soil. In this study, soil samples were collected from areas of long-term continuous cotton crops with the aim of obtaining microbial resources applicable for remediation of pyrethroid pesticide contamination suitable for the soil type and climate of that area. Soil samples were first used to culture microbial flora capable of degrading beta-cypermethrin using an enrichment culture method. Structural changes and ultimate microbial floral composition during enrichment were analyzed by high-throughput sequencing. Four strains capable of degrading beta-cypermethrin were isolated and preliminarily classified. Finally, comparative rates and speeds of degradation of beta-cypermethrin between relevant microbial flora and single strains were determined. After continuous subculture for 3 weeks, soil sample microbial flora formed a new type of microbial flora by rapid succession, which showed stable growth by utilizing beta-cypermethrin as the sole carbon source (GXzq). This microbial flora mainly consisted of Pseudomonas, Hyphomicrobium, Dokdonella, and Methyloversatilis. Analysis of the microbial flora also permitted separation of four additional strains; i.e., GXZQ4, GXZQ6, GXZQ7, and GXZQ13 that, respectively, belonged to Streptomyces, Enterobacter, Streptomyces, and Pseudomonas. Under culture conditions of 37 °C and 180 rpm, the degradation rate of beta-cypermethrin by GXzq was as high as 89.84% within 96 h, which exceeded that achieved by the single strains GXZQ4, GXZQ6, GXZQ7, and GXZQ13 and their derived microbial flora GXh.

[Application of recombinase polymerase amplification in the detection of Pseudomonas aeruginosa].

PubMed

Jin, X J; Gong, Y L; Yang, L; Mo, B H; Peng, Y Z; He, P; Zhao, J N; Li, X L

2018-04-20

Objective: To establish an optimized method of recombinase polymerase amplification (RPA) to rapidly detect Pseudomonas aeruginosa in clinic. Methods: (1) The DNA templates of one standard Pseudomonas aeruginosa strain was extracted and detected by polymerase chain reaction (PCR), real-time fluorescence quantitative PCR and RPA. Time of sample loading, time of amplification, and time of detection of the three methods were recorded. (2) One standard Pseudomonas aeruginosa strain was diluted in 7 concentrations of 1×10(7,) 1×10(6,) 1×10(5,) 1×10(4,) 1×10(3,) 1×10(2,) and 1×10(1) colony forming unit (CFU)/mL after recovery and cultivation. The DNA templates of Pseudomonas aeruginosa and negative control strain Pseudomonas putida were extracted and detected by PCR, real-time fluorescence quantitative PCR, and RPA separately. The sensitivity of the three methods in detecting Pseudomonas aeruginosa was analyzed. (3) The DNA templates of one standard Pseudomonas aeruginosa strain and four negative control strains ( Staphylococcus aureus, Acinetobacter baumanii, Candida albicans, and Pseudomonas putida ) were extracted separately, and then they were detected by PCR, real-time fluorescence quantitative PCR, and RPA. The specificity of the three methods in detecting Pseudomonas aeruginosa was analyzed. (4) The DNA templates of 28 clinical strains of Pseudomonas aeruginosa preserved in glycerin, 1 clinical strain of which was taken by cotton swab, and negative control strain Pseudomonas putida were extracted separately, and then they were detected by RPA. Positive amplification signals of the clinical strains were observed, and the detection rate was calculated. All experiments were repeated for 3 times. Sensitivity results were analyzed by GraphPad Prism 5.01 statistical software. Results: (1) The loading time of RPA, PCR, and real-time fluorescence quantitative PCR for detecting Pseudomonas aeruginosa were all 20 minutes. In PCR, time of amplification was 98 minutes

Small RNAs regulate the biocontrol property of fluorescent Pseudomonas strain Psd.

PubMed

Upadhyay, Anamika; Kochar, Mandira; Upadhyay, Ashutosh; Tripathy, Soumya; Rajam, Manchikatla Venkat; Srivastava, Sheela

2017-03-01

The production of biocontrol factors by Pseudomonads is reported to be controlled at the post-transcriptional level by the GacS/GacA signal transduction pathway. This involves RNA-binding translational repressor proteins, RsmA and RsmE, and the small regulatory RNAs (sRNAs) RsmX, RsmY, and RsmZ. While the former represses genes involved in secondary metabolite production, the latter relieves this repression at the end of exponential growth. We have studied the fluorescent Pseudomonas strain Psd, possessing good biocontrol potential, and confirmed the presence of rsmY and rsmZ by PCR amplification. Gene constructs for all the three small RNAs (RsmX, RsmY and RsmZ) carried on broad host-range plasmid, pME6032 were mobilized into strain Psd. Expression analysis of gacA in the recombinant strains over-expressing rsmX (Psd-pME7320), rsmY (Psd-pME6359) and rsmZ (Psd-pME6918) revealed a significant upregulation of the response regulator. Besides, a remarkable down-regulation of rsmA was also reported in all the strains. The variant strains were found to produce comparatively higher levels of phenazines. Indole acetic acid levels were higher to some extent, and strain Psd-pME6918 also showed elevated production of HCN. The tomato seedlings infected with Fusarium oxysporum and Verticillium dahliae in the presence of culture filtrate of the recombinant strains showed better plant protection response in comparison to the wild-type strain Psd. These results suggest that small RNAs are important determinants in regulation of the biocontrol property of strain Psd. Copyright © 2016 Elsevier GmbH. All rights reserved.

Pseudomonas cremoricolorata Strain ND07 Produces N-acyl Homoserine Lactones as Quorum Sensing Molecules

PubMed Central

Yunos, Nina Yusrina Muhamad; Tan, Wen-Si; Koh, Chong-Lek; Sam, Choon-Kook; Mohamad, Nur Izzati; Tan, Pui-Wan; Adrian, Tan-Guan-Sheng; Yin, Wai-Fong; Chan, Kok-Gan

2014-01-01

Quorum sensing (QS) is a bacterial cell-to-cell communication system controlling QS-mediated genes which is synchronized with the population density. The regulation of specific gene activity is dependent on the signaling molecules produced, namely N-acyl homoserine lactones (AHLs). We report here the identification and characterization of AHLs produced by bacterial strain ND07 isolated from a Malaysian fresh water sample. Molecular identification showed that strain ND07 is clustered closely to Pseudomonas cremoricolorata. Spent culture supernatant extract of P. cremoricolorata strain ND07 activated the AHL biosensor Chromobacterium violaceum CV026. Using high resolution triple quadrupole liquid chromatography-mass spectrometry, it was confirmed that P. cremoricolorata strain ND07 produced N-octanoyl-l-homoserine lactone (C8-HSL) and N-decanoyl-l-homoserine lactone (C10-HSL). To the best of our knowledge, this is the first documentation on the production of C10-HSL in P. cremoricolorata strain ND07. PMID:24984061

Contrasting effects of a nonionic surfactant on the biotransformation of polycyclic aromatic hydrocarbons to cis-dihydrodiols by soil bacteria

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

Allen, C.C.R.; Boyd, D.R.; Hempenstall, F.

The biotransformation of the polycyclic aromatic hydrocarbons (PAHs) naphthalene and phenanthrene was investigated by using two dioxygenase-expressing bacteria, Pseudomonas sp. strain 9816/11 and Sphingomonas yanoikuyae B8/36, under conditions which facilitate mass-transfer limited substrate oxidation. Both of these strains are mutants that accumulate cis-dihydrodiol metabolites under the reaction conditions used. The effects of the nonpolar solvent 2,2,4,4,6,8,8-heptamethylnonane (HMN) and the nonionic surfactant Triton X-100 on the rate of accumulation of these metabolites were determined. HMN increased the rate of accumulation of metabolites for both microorganisms, with both substrates. The enhancement effect was most noticeable with phenanthrene, which has a lower aqueousmore » solubility than naphthalene. Triton X-100 increased the rate of oxidation of the PAHs with strain 9816/11 with the effect being most noticeable when phenanthrene was used as a substrate. However, the surfactant inhibited the biotransformation of both naphthalene and phenanthrene with strain B8/36 under the same conditions. The observation that a nonionic surfactant could have such contrasting effects on PAH oxidation by different bacteria, which are known to be important for the degradation of these compounds in the environment, may explain why previous research on the application of the surfactants to PAH bioremediation has yielded inconclusive results. The surfactant inhibited growth of the wild-type strain S. yanoikuyae B1 on aromatic compounds but did not inhibit B8/36 dioxygenase enzyme activity in vitro.« less

Pseudomonas fluorescens transportome is linked to strain-specific plant growth promotion in Aspen seedlings under nutrient stress

DOE PAGES

Shinde, Shalaka; Cumming, Jonathan R.; Collart, Frank R.; ...

2017-03-21

Diverse communities of bacteria colonize plant roots and the rhizosphere. Many of these rhizobacteria are symbionts and provide plant growth promotion (PGP) services, protecting the plant from biotic and abiotic stresses and increasing plant productivity by providing access to nutrients that would otherwise be unavailable to roots. In return, these symbiotic bacteria receive photosynthetically-derived carbon (C), in the form of sugars and organic acids, from plant root exudates. PGP activities have been characterized for a variety of forest tree species and are important in C cycling and sequestration in terrestrial ecosystems. The molecular mechanisms of these PGP activities, however, aremore » less well-known. In a previous analysis of Pseudomonas genomes, we found that the bacterial transportome, the aggregate activity of a bacteria's transmembrane transporters, was most predictive for the ecological niche of Pseudomonads in the rhizosphere. Here, we used Populus tremuloides Michx. (trembling aspen) seedlings inoculated with one of three Pseudomonas fluorescens strains (Pf0-1, SBW25, and WH6) and one Pseudomonas protegens (Pf-5) as a laboratory model to further investigate the relationships between the predicted transportomic capacity of a bacterial strain and its observed PGP effects in laboratory cultures. Conditions of low nitrogen (N) or low phosphorus (P) availability and the corresponding replete media conditions were investigated. We measured phenotypic and biochemical parameters of P. tremuloides seedlings and correlated P fluorescens strain-specific transportomic capacities with P. tremuloides seedling phenotype to predict the strain and nutrient environment-specific transporter functions that lead to experimentally observed, strain, and media-specific PGP activities and the capacity to protect plants against nutrient stress. These predicted transportomic functions fall in three groups: (i) transport of compounds that modulate aspen seedling root

Pseudomonas fluorescens transportome is linked to strain-specific plant growth promotion in Aspen seedlings under nutrient stress

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

Shinde, Shalaka; Cumming, Jonathan R.; Collart, Frank R.

Diverse communities of bacteria colonize plant roots and the rhizosphere. Many of these rhizobacteria are symbionts and provide plant growth promotion (PGP) services, protecting the plant from biotic and abiotic stresses and increasing plant productivity by providing access to nutrients that would otherwise be unavailable to roots. In return, these symbiotic bacteria receive photosynthetically-derived carbon (C), in the form of sugars and organic acids, from plant root exudates. PGP activities have been characterized for a variety of forest tree species and are important in C cycling and sequestration in terrestrial ecosystems. The molecular mechanisms of these PGP activities, however, aremore » less well-known. In a previous analysis of Pseudomonas genomes, we found that the bacterial transportome, the aggregate activity of a bacteria's transmembrane transporters, was most predictive for the ecological niche of Pseudomonads in the rhizosphere. Here, we used Populus tremuloides Michx. (trembling aspen) seedlings inoculated with one of three Pseudomonas fluorescens strains (Pf0-1, SBW25, and WH6) and one Pseudomonas protegens (Pf-5) as a laboratory model to further investigate the relationships between the predicted transportomic capacity of a bacterial strain and its observed PGP effects in laboratory cultures. Conditions of low nitrogen (N) or low phosphorus (P) availability and the corresponding replete media conditions were investigated. We measured phenotypic and biochemical parameters of P. tremuloides seedlings and correlated P fluorescens strain-specific transportomic capacities with P. tremuloides seedling phenotype to predict the strain and nutrient environment-specific transporter functions that lead to experimentally observed, strain, and media-specific PGP activities and the capacity to protect plants against nutrient stress. These predicted transportomic functions fall in three groups: (i) transport of compounds that modulate aspen seedling root

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

Indigenous Pseudomonas spp. Strains from the Olive (Olea europaea L.) Rhizosphere as Effective Biocontrol Agents against Verticillium dahliae: From the Host Roots to the Bacterial Genomes

PubMed Central

Gómez-Lama Cabanás, Carmen; Legarda, Garikoitz; Ruano-Rosa, David; Pizarro-Tobías, Paloma; Valverde-Corredor, Antonio; Niqui, José L.; Triviño, Juan C.; Roca, Amalia; Mercado-Blanco, Jesús

2018-01-01

The use of biological control agents (BCA), alone or in combination with other management measures, has gained attention over the past decades, driven by the need to seek for sustainable and eco-friendly alternatives to confront plant pathogens. The rhizosphere of olive (Olea europaea L.) plants is a source of bacteria with potential as biocontrol tools against Verticillium wilt of olive (VWO) caused by Verticillium dahliae Kleb. A collection of bacterial isolates from healthy nursery-produced olive (cultivar Picual, susceptible to VWO) plants was generated based on morphological, biochemical and metabolic characteristics, chemical sensitivities, and on their in vitro antagonistic activity against several olive pathogens. Three strains (PIC25, PIC105, and PICF141) showing high in vitro inhibition ability of pathogens' growth, particularly against V. dahliae, were eventually selected. Their effectiveness against VWO caused by the defoliating pathotype of V. dahliae was also demonstrated, strain PICF141 being the rhizobacteria showing the best performance as BCA. Genotypic and phenotypic traits traditionally associated with plant growth promotion and/or biocontrol abilities were evaluated as well (e.g., phytase, xylanase, catalase, cellulase, chitinase, glucanase activities, and siderophore and HCN production). Multi-locus sequence analyses of conserved genes enabled the identification of these strains as Pseudomonas spp. Strain PICF141 was affiliated to the “Pseudomonas mandelii subgroup,” within the “Pseudomonas fluorescens group,” Pseudomonas lini being the closest species. Strains PIC25 and PIC105 were affiliated to the “Pseudomonas aeruginosa group,” Pseudomonas indica being the closest relative. Moreover, we identified P. indica (PIC105) for the first time as a BCA. Genome sequencing and in silico analyses allowed the identification of traits commonly associated with plant-bacteria interactions. Finally, the root colonization ability of these olive

Indigenous Pseudomonas spp. Strains from the Olive (Olea europaea L.) Rhizosphere as Effective Biocontrol Agents against Verticillium dahliae: From the Host Roots to the Bacterial Genomes.

PubMed

Gómez-Lama Cabanás, Carmen; Legarda, Garikoitz; Ruano-Rosa, David; Pizarro-Tobías, Paloma; Valverde-Corredor, Antonio; Niqui, José L; Triviño, Juan C; Roca, Amalia; Mercado-Blanco, Jesús

2018-01-01

The use of biological control agents (BCA), alone or in combination with other management measures, has gained attention over the past decades, driven by the need to seek for sustainable and eco-friendly alternatives to confront plant pathogens. The rhizosphere of olive ( Olea europaea L.) plants is a source of bacteria with potential as biocontrol tools against Verticillium wilt of olive (VWO) caused by Verticillium dahliae Kleb. A collection of bacterial isolates from healthy nursery-produced olive (cultivar Picual, susceptible to VWO) plants was generated based on morphological, biochemical and metabolic characteristics, chemical sensitivities, and on their in vitro antagonistic activity against several olive pathogens. Three strains (PIC25, PIC105, and PICF141) showing high in vitro inhibition ability of pathogens' growth, particularly against V. dahliae , were eventually selected. Their effectiveness against VWO caused by the defoliating pathotype of V. dahliae was also demonstrated, strain PICF141 being the rhizobacteria showing the best performance as BCA. Genotypic and phenotypic traits traditionally associated with plant growth promotion and/or biocontrol abilities were evaluated as well (e.g., phytase, xylanase, catalase, cellulase, chitinase, glucanase activities, and siderophore and HCN production). Multi-locus sequence analyses of conserved genes enabled the identification of these strains as Pseudomonas spp. Strain PICF141 was affiliated to the " Pseudomonas mandelii subgroup," within the " Pseudomonas fluorescens group," Pseudomonas lini being the closest species. Strains PIC25 and PIC105 were affiliated to the " Pseudomonas aeruginosa group," Pseudomonas indica being the closest relative. Moreover, we identified P. indica (PIC105) for the first time as a BCA. Genome sequencing and in silico analyses allowed the identification of traits commonly associated with plant-bacteria interactions. Finally, the root colonization ability of these olive

Antibacterial activity of extracellular compounds produced by a Pseudomonas strain against methicillin-resistant Staphylococcus aureus (MRSA) strains

PubMed Central

2013-01-01

Background The emergence of multidrug-resistant bacteria is a world health problem. Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) strains, is one of the most important human pathogens associated with hospital and community-acquired infections. The aim of this work was to evaluate the antibacterial activity of a Pseudomonas aeruginosa-derived compound against MRSA strains. Methods Thirty clinical MRSA strains were isolated, and three standard MRSA strains were evaluated. The extracellular compounds were purified by vacuum liquid chromatography. Evaluation of antibacterial activity was performed by agar diffusion technique, determination of the minimal inhibitory concentration, curve of growth and viability and scanning electron microscopy. Interaction of an extracellular compound with silver nanoparticle was studied to evaluate antibacterial effect. Results The F3 (ethyl acetate) and F3d (dichloromethane- ethyl acetate) fractions demonstrated antibacterial activity against the MRSA strains. Phenazine-1-carboxamide was identified and purified from the F3d fraction and demonstrated slight antibacterial activity against MRSA, and synergic effect when combined with silver nanoparticles produced by Fusarium oxysporum. Organohalogen compound was purified from this fraction showing high antibacterial effect. Using scanning electron microscopy, we show that the F3d fraction caused morphological changes to the cell wall of the MRSA strains. Conclusions These results suggest that P. aeruginosa-produced compounds such as phenazines have inhibitory effects against MRSA and may be a good alternative treatment to control infections caused by MRSA. PMID:23773484

A Method for Detection of Pseudobactin, the Siderophore Produced by a Plant-Growth-Promoting Pseudomonas Strain, in the Barley Rhizosphere

PubMed Central

Buyer, Jeffrey S.; Kratzke, Marian G.; Sikora, Lawrence J.

1993-01-01

Detection in the rhizosphere of the siderophore produced by an inoculated microorganism is critical to determining the role of microbial iron chelators on plant growth promotion. We previously reported the development of monoclonal antibodies (MAb) to ferric pseudobactin, the siderophore of plant-growth-promoting Pseudomonas strain B10. One of these MAb reacted less strongly to pseudobactin than to ferric pseudobactin. The MAb reacted to Al(III), Cr(III), Cu(II), and Mn(II) complexes of pseudobactin at a level similar to the level at which it reacted to ferric pseudobactin and reacted less to the Zn(II) complex, but these metals would make up only a small fraction of chelated pseudobactin in soil on the basis of relative abundance of metals and relative binding constants. Fourteen-day-old barley plants grown in limed and autoclaved soil were inoculated with 109 CFU of Pseudomonas strain Sm1-3, a strain of Pseudomonas B10 Rifr Nalr selected for enhanced colonization, and sampled 3 days later. Extraction and analysis of the roots and surrounding soil using the MAb in an immunoassay indicated a concentration of 3.5 × 10-10 mol of ferric pseudobacting g-1 (wet weight). This is the first direct measurement of a pseudobactin siderophore in soil or rhizosphere samples. PMID:16348884

Pseudomonas screening assay

NASA Technical Reports Server (NTRS)

Margalit, Ruth (Inventor)

1993-01-01

A method for the detection of Pseudomonas bacteria is described where an Azurin-specific antibody is employed for detecting the presence of Azurin in a test sample. The detection of the presence of Azurin in the sample is a conclusive indicator of the presence of the Pseudomonas bacteria since the Azurin protein is a specific marker for this bacterial strain.

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.

Isolation and characterization of onion degrading bacteria from onion waste produced in South Buenos Aires province, Argentina.

PubMed

Rinland, María Emilia; Gómez, Marisa Anahí

2015-03-01

Onion production in Argentina generates a significant amount of waste. Finding an effective method to recycle it is a matter of environmental concern. Among organic waste reuse techniques, anaerobic digestion could be a valuable alternative to current practices. Substrate inoculation with appropriate bacterial strains enhances the rate-limiting step (hydrolysis) of anaerobic digestion of biomass wastes. Selection of indigenous bacteria with the ability to degrade onion waste could be a good approach to find a suitable bioaugmentation or pretreatment agent. We isolated bacterial strains from onion waste in different degradation stages and from different localities. In order to characterize and select the best candidates, we analyzed the growth patterns of the isolates in a medium prepared with onion juice as the main source of nutrients and we evaluated carbon source utilization. Nine strains were selected to test their ability to grow using onion tissue and the five most remarkable ones were identified by 16S rRNA gene sequencing. Strains belonged to the genera Pseudoxanthomonas, Bacillus, Micrococcus and Pseudomonas. Two strains, Bacillus subtilis subsp. subtillis MB2-62 and Pseudomonas poae VE-74 have characteristics that make them promising candidates for bioaugmentation or pretreatment purposes.

Use of mycelia as paths for the isolation of contaminant‐degrading bacteria from soil

PubMed Central

Furuno, Shoko; Remer, Rita; Chatzinotas, Antonis; Harms, Hauke; Wick, Lukas Y.

2012-01-01

Summary Mycelia of fungi and soil oomycetes have recently been found to act as effective paths boosting bacterial mobility and bioaccessibility of contaminants in vadose environments. In this study, we demonstrate that mycelia can be used for targeted separation and isolation of contaminant‐degrading bacteria from soil. In a ‘proof of concept’ study we developed a novel approach to isolate bacteria from contaminated soil using mycelia of the soil oomycete Pythium ultimum as translocation networks for bacteria and the polycyclic aromatic hydrocarbon naphthalene (NAPH) as selective carbon source. NAPH‐degrading bacterial isolates were affiliated with the genera Xanthomonas, Rhodococcus and Pseudomonas. Except for Rhodococcus the NAPH‐degrading isolates exhibited significant motility as observed in standard swarming and swimming motility assays. All steps of the isolation procedures were followed by cultivation‐independent terminal 16S rRNA gene terminal fragment length polymorphism (T‐RFLP) analysis. Interestingly, a high similarity (63%) between both the cultivable NAPH‐degrading migrant and the cultivable parent soil bacterial community profiles was observed. This suggests that mycelial networks generally confer mobility to native, contaminant‐degrading soil bacteria. Targeted, mycelia‐based dispersal hence may have high potential for the isolation of bacteria with biotechnologically useful properties. PMID:22014110

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.

Mechanism for Clastogenic Activity of Naphthalene

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

Buchholz, Bruce A.

2016-06-24

Naphthalene incubations form DNA adducts in vitro in a dose dependent manner in both mouse and rat tissues. Rodent tissue incubations with naphthalene indicate that naphthalene forms as many DNA adducts as Benzo(a)pyrene, a known DNA binding carcinogen. The mouse airway has the greatest number of DNA adducts, corresponding to the higher metabolic activation of naphthalene in this location. Both rat tissues, the rat olfactory (tumor target) and the airways (non-tumor target), have similar levels of NA-DNA adducts, indicating that short term measures of initial adduct formation do not directly correlate with sites of tumor formation in the NTP bioassays.

Naphthalene

Integrated Risk Information System (IRIS)

Naphthalene ; CASRN 91 - 20 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

Secondary metabolite production by Pseudomonas fluorescens strain Pf-5 confers protection against Naegleria americana in the wheat rhizosphere

USDA-ARS?s Scientific Manuscript database

Bacteria employ a variety of morphological and metabolic mechanisms to avoid protozoan predation. In Pseudomonas fluorescens strains SS101 and SBW25, cyclic lipopeptide (CLP) production served as a defense mechanism that limited predation by the amoeba-flagellate Naegleria americana, and secondary m...

Comparative genomic analysis of multiple strains of two unusual plant pathogens: Pseudomonas corrugata and Pseudomonas mediterranea

PubMed Central

Trantas, Emmanouil A.; Licciardello, Grazia; Almeida, Nalvo F.; Witek, Kamil; Strano, Cinzia P.; Duxbury, Zane; Ververidis, Filippos; Goumas, Dimitrios E.; Jones, Jonathan D. G.; Guttman, David S.; Catara, Vittoria; Sarris, Panagiotis F.

2015-01-01

The non-fluorescent pseudomonads, Pseudomonas corrugata (Pcor) and P. mediterranea (Pmed), are closely related species that cause pith necrosis, a disease of tomato that causes severe crop losses. However, they also show strong antagonistic effects against economically important pathogens, demonstrating their potential for utilization as biological control agents. In addition, their metabolic versatility makes them attractive for the production of commercial biomolecules and bioremediation. An extensive comparative genomics study is required to dissect the mechanisms that Pcor and Pmed employ to cause disease, prevent disease caused by other pathogens, and to mine their genomes for genes that encode proteins involved in commercially important chemical pathways. Here, we present the draft genomes of nine Pcor and Pmed strains from different geographical locations. This analysis covered significant genetic heterogeneity and allowed in-depth genomic comparison. All examined strains were able to trigger symptoms in tomato plants but not all induced a hypersensitive-like response in Nicotiana benthamiana. Genome-mining revealed the absence of type III secretion system and known type III effector-encoding genes from all examined Pcor and Pmed strains. The lack of a type III secretion system appears to be unique among the plant pathogenic pseudomonads. Several gene clusters coding for type VI secretion system were detected in all genomes. Genome-mining also revealed the presence of gene clusters for biosynthesis of siderophores, polyketides, non-ribosomal peptides, and hydrogen cyanide. A highly conserved quorum sensing system was detected in all strains, although species specific differences were observed. Our study provides the basis for in-depth investigations regarding the molecular mechanisms underlying virulence strategies in the battle between plants and microbes. PMID:26300874

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

Degradation of sinigrin by Lactobacillus agilis strain R16.

PubMed

Llanos Palop, M; Smiths, J P; Brink, B T

1995-07-01

Forty-two lactobacilli were screened for their potential to degrade glucosinolate sinigrin. One of them, strain R16, demonstrated a high level of sinigrin degradation; it was identified as Lactobacillus agilis. The sinigrin degrading activity of L. agilis R16 could only be demonstrated when intact cells were used. The products of sinigrin degradation are allyl-isothiocyanate (AITC) and glucose (which is further fermented to DL-lactic acid), suggesting that myrosinase activity is involved. The activity was induced by the presence of sinigrin. Glucose inhibited the myrosinase activity, even in induced cells. Lactobacillus agilis R16 was able to grow on an extract of brown mustard seed and caused glucosinolate degradation.

Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

PubMed

Gilani, Razia Alam; Rafique, Mazhar; Rehman, Abdul; Munis, Muhammad Farooq Hussain; Rehman, Shafiq Ur; Chaudhary, Hassan Javed

2016-02-01

Chlorpyrifos is an organophosphorus pesticide commonly used in agriculture. It is noxious to a variety of organisms that include living soil biota along with beneficial arthropods, fish, birds, humans, animals, and plants. Exposure to chlorpyrifos may cause detrimental effects as delayed seedling emergence, fruit deformities, and abnormal cell division. Contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. The 3,5,6-trichloro-2-pyridinol (TCP) and diethylthiophosphate (DETP) as primary products are made when chlorpyrifos is degraded by soil microorganisms which further break into nontoxic metabolites as CO(2), H(2)O, and NH(3). Pseudomonas is a diversified genus possessing a series of catabolic pathways and enzymes involved in pesticide degradation. Pseudomonas putida MAS-1 is reported to be more efficient in chlorpyrifos degradation by a rate of 90% in 24 h among Pseudomonas genus. The current review analyzed the comparative potential of bacterial species in Pseudomonas genus for degradation of chlorpyrifos thus, expressing an ecofriendly approach for the treatment of environmental contaminants like pesticides. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Genome Sequence of Pseudomonas aeruginosa Strain LCT-PA220, Which Was Selected after Space Flight by Using Biolog's Powerful Carbon Source Utilization Technology.

PubMed

Xu, Guogang; Hu, Juan; Fang, Xiangqun; Zhang, Xuelin; Wang, Junfeng; Guo, Yinghua; Li, Tianzhi; Chen, Zhenghong; Dai, Wenkui; Liu, Changting

2014-03-13

To explore the changes of Pseudomonas aeruginosa in space flight, we present the draft genome sequence of P. aeruginosa strain LCT-PA220, which originated from a P. aeruginosa strain, ATCC 27853, that traveled on the Shenzhou-VIII spacecraft.

Heterogeneity of heat-resistant proteases from milk Pseudomonas species.

PubMed

Marchand, Sophie; Vandriesche, Gonzalez; Coorevits, An; Coudijzer, Katleen; De Jonghe, Valerie; Dewettinck, Koen; De Vos, Paul; Devreese, Bart; Heyndrickx, Marc; De Block, Jan

2009-07-31

Pseudomonas fragi, Pseudomonas lundensis and members of the Pseudomonas fluorescens group may spoil Ultra High Temperature (UHT) treated milk and dairy products, due to the production of heat-stable proteases in the cold chain of raw milk. Since the aprX gene codes for a heat-resistant protease in P. fluorescens, the presence of this gene has also been investigated in other members of the genus. For this purpose an aprX-screening PCR test has been developed. Twenty-nine representatives of important milk Pseudomonas species and thirty-five reference strains were screened. In 42 out of 55 investigated Pseudomonas strains, the aprX gene was detected, which proves the potential of the aprX-PCR test as a screening tool for potentially proteolytic Pseudomonas strains in milk samples. An extensive study of the obtained aprX-sequences on the DNA and the amino acid level, however, revealed a large heterogeneity within the investigated milk isolates. Although this heterogeneity sets limitations to a general detection method for all proteolytic Pseudomonas strains in milk, it offers a great potential for the development of a multiplex PCR screening test targeting individual aprX-genes. Furthermore, our data illustrated the potential use of the aprX gene as a taxonomic marker, which may help in resolving the current taxonomic deadlock in the P. fluorescens group.

Antibiotic Resistance Determinants in a Pseudomonas putida Strain Isolated from a Hospital

PubMed Central

Duque, Estrella; Fernández, Matilde; Molina-Santiago, Carlos; Roca, Amalia; Porcel, Mario; de la Torre, Jesús; Segura, Ana; Plesiat, Patrick; Jeannot, Katy; Ramos, Juan-Luis

2014-01-01

Environmental microbes harbor an enormous pool of antibiotic and biocide resistance genes that can impact the resistance profiles of animal and human pathogens via horizontal gene transfer. Pseudomonas putida strains are ubiquitous in soil and water but have been seldom isolated from humans. We have established a collection of P. putida strains isolated from in-patients in different hospitals in France. One of the isolated strains (HB3267) kills insects and is resistant to the majority of the antibiotics used in laboratories and hospitals, including aminoglycosides, ß-lactams, cationic peptides, chromoprotein enediyne antibiotics, dihydrofolate reductase inhibitors, fluoroquinolones and quinolones, glycopeptide antibiotics, macrolides, polyketides and sulfonamides. Similar to other P. putida clinical isolates the strain was sensitive to amikacin. To shed light on the broad pattern of antibiotic resistance, which is rarely found in clinical isolates of this species, the genome of this strain was sequenced and analysed. The study revealed that the determinants of multiple resistance are both chromosomally-borne as well as located on the pPC9 plasmid. Further analysis indicated that pPC9 has recruited antibiotic and biocide resistance genes from environmental microorganisms as well as from opportunistic and true human pathogens. The pPC9 plasmid is not self-transmissible, but can be mobilized by other bacterial plasmids making it capable of spreading antibiotic resistant determinants to new hosts. PMID:24465371

Effect of exogenous reductant on growth and iron mobilization from ferrihydrite by the Pseudomonas mendocina ymp strain.

PubMed

Dhungana, Suraj; Anthony, Charles R; Hersman, Larry E

2007-05-01

Growth of the Pseudomonas mendocina ymp strain on insoluble ferrihydrite is enhanced by exogenous reductants with concurrent increase in soluble iron concentrations. This shows that exogenous reductants play a substantial role in the overall microbial iron bioavailability. The exogenous reductants may work together with the siderophores, Fe-scavenging agents, to facilitate ferrihydrite dissolution.

Pseudomonas aeruginosa ATCC 9027 is a non-virulent strain suitable for mono-rhamnolipids production.

PubMed

Grosso-Becerra, María-Victoria; González-Valdez, Abigail; Granados-Martínez, María-Jessica; Morales, Estefanía; Servín-González, Luis; Méndez, José-Luis; Delgado, Gabriela; Morales-Espinosa, Rosario; Ponce-Soto, Gabriel-Yaxal; Cocotl-Yañez, Miguel; Soberón-Chávez, Gloria

2016-12-01

Rhamnolipids produced by Pseudomonas aeruginosa are biosurfactants with a high biotechnological potential, but their extensive commercialization is limited by the potential virulence of P. aeruginosa and by restrictions in producing these surfactants in heterologous hosts. In this work, we report the characterization of P. aeruginosa strain ATCC 9027 in terms of its genome-sequence, virulence, antibiotic resistance, and its ability to produce mono-rhamnolipids when carrying plasmids with different cloned genes from the type strain PAO1. The genes that were expressed from the plasmids are those coding for enzymes involved in the synthesis of this biosurfactant (rhlA and rhlB), as well as the gene that codes for the RhlR transcriptional regulator. We confirm that strain ATCC 9027 forms part of the PA7 clade, but contrary to strain PA7, it is sensitive to antibiotics and is completely avirulent in a mouse model. We also report that strain ATCC 9027 mono-rhamnolipid synthesis is limited by the expression of the rhlAB-R operon. Thus, this strain carrying the rhlAB-R operon produces similar rhamnolipids levels as PAO1 strain. We determined that strain ATCC 9027 with rhlAB-R operon was not virulent to mice. These results show that strain ATCC 9027, expressing PAO1 rhlAB-R operon, has a high biotechnological potential for industrial mono-rhamnolipid production.

Degradation of paracetamol by pure bacterial cultures and their microbial consortium.

PubMed

Zhang, Lili; Hu, Jun; Zhu, Runye; Zhou, Qingwei; Chen, Jianmeng

2013-04-01

Three bacterial strains utilizing paracetamol as the sole carbon, nitrogen, and energy source were isolated from a paracetamol-degrading aerobic aggregate, and assigned to species of the genera Stenotrophomonas and Pseudomonas. The Stenotrophomonas species have not included any known paracetamol degraders until now. In batch cultures, the organisms f1, f2, and fg-2 could perform complete degradation of paracetamol at concentrations of 400, 2,500, and 2,000 mg/L or below, respectively. A combination of three microbial strains resulted in significantly improved degradation and mineralization of paracetamol. The co-culture was able to use paracetamol up to concentrations of 4,000 mg/L, and mineralized 87.1 % of the added paracetamol at the initial of 2,000 mg/L. Two key metabolites of the biodegradation pathway of paracetamol, 4-aminophenol, and hydroquinone were detected. Paracetamol was degraded predominantly via 4-aminophenol to hydroquinone with subsequent ring fission, suggesting new pathways for paracetamol-degrading bacteria. The degradation of paracetamol could thus be performed by the single isolates, but is stimulated by a synergistic interaction of the three-member consortium, suggesting a possible complementary interaction among the various isolates. The exact roles of each of the strains in the consortium need to be further elucidated.

Nitrogen Source Stabilization of Quorum Sensing in the Pseudomonas aeruginosa Bioaugmentation Strain SD-1.

PubMed

Wang, Mei-Zhen; Lai, Bai-Min; Dandekar, Ajai A; Yang, Yu-Sheng; Li, Na; Yin, Jun; Shen, Dong-Sheng

2017-08-15

Pseudomonas aeruginosa SD-1 is efficient at degrading aromatic compounds and can therefore contribute to the bioremediation of wastewater. P. aeruginosa uses quorum sensing (QS) to regulate the production of numerous secreted "public goods." In wastewater bioaugmentation applications, there are myriad nitrogen sources, and we queried whether various nitrogen sources impact the stabilities of both QS and the bacterial populations. In a laboratory strain of P. aeruginosa , PAO1, the absence of a nitrogen source has been shown to destabilize these populations through the emergence of QS mutant "cheaters." We tested the ability of SD-1 to grow in casein broth, a condition that requires QS for growth, when the nitrogen source with either NH 4 Cl, NaNO 3 , or NaNO 2 or with no added nitrogen source. There was great variability in susceptibility to invasion by QS mutant cheaters and, by extension, the stability of the SD-1 population. When grown with NH 4 Cl as an extra nitrogen source, no population collapse was observed; by contrast, two-thirds of cultures grown in the presence of NaNO 2 collapsed. In the populations that collapsed, the frequency of social cheaters exceeded 40%. NaNO 3 and NaNO 2 directly favor QS mutants of P. aeruginosa SD-1. Although the mechanism by which these nitrogen sources act is not clear, these data indicate that the metabolism of nitrogen can affect the stability of bacterial populations, an important observation for continuing industrial applications with this species. IMPORTANCE Bioaugmentation as a method to help remediate wastewater pollutant streams holds significant potential to enhance traditional methods of treatment. Addition of microbes that can catabolize organic pollutants can be an effective method to remove several toxic compounds. Such bioaugmented strains of bacteria have been shown to be susceptible to competition from the microbiota that are present in wastewater streams, limiting their potential effectiveness. Here, we

Strains of the soil fungus Mortierella show different degradation potentials for the phenylurea herbicide diuron.

PubMed

Ellegaard-Jensen, Lea; Aamand, Jens; Kragelund, Birthe B; Johnsen, Anders H; Rosendahl, Søren

2013-11-01

Microbial pesticide degradation studies have until now mainly focused on bacteria, although fungi have also been shown to degrade pesticides. In this study we clarify the background for the ability of the common soil fungus Mortierella to degrade the phenylurea herbicide diuron. Diuron degradation potentials of five Mortierella strains were compared, and the role of carbon and nitrogen for the degradation process was investigated. Results showed that the ability to degrade diuron varied greatly among the Mortierella strains tested, and the strains able to degrade diuron were closely related. Degradation of diuron was fastest in carbon and nitrogen rich media while suboptimal nutrient levels restricted degradation, making it unlikely that Mortierella utilize diuron as carbon or nitrogen sources. Degradation kinetics showed that diuron degradation was followed by formation of the metabolites 1-(3,4-dichlorophenyl)-3-methylurea, 1-(3,4-dichlorophenyl)urea and an hitherto unknown metabolite suggested to be 1-(3,4-dichlorophenyl)-3-methylideneurea.

Yields of Bacterial Cells from Hydrocarbons

PubMed Central

Wodzinski, Richard S.; Johnson, Marvin J.

1968-01-01

A strain of Nocardia and one of Pseudomonas, both isolated on pristane (2,6,10,14-tetramethylpentadecane), gave cell yields of approximately 100% on n-octadecane and pristane. Both organisms grew more rapidly on the n-octadecane than on the pristane. A mixed culture, isolated on 3-methylheptane, whose two components were identified as species of Pseudomonas and of Nocardia, gave approximately 100% cell yields and grew with generation times of about 5 hr on n-heptane, n-octane, and 2-methylheptane. The generation time on 3-methylheptane was 8.6 hr and the cell yield was only 79%. A strain of Pseudomonas isolated from naphthalene enrichments and one from phenanthrene enrichments both gave a cell yield of 50% on naphthalene. The phenanthrene isolate gave a cell yield of 40% on phenanthrene. A Nocardia species isolated on benzene gave a 79% cell yield on benzene. The generation times of the bacteria isolated on aromatic hydrocarbons were related to the solubility of the aromatic hydrocarbons on which they were grown; the more insoluble hydrocarbons gave slower growth. PMID:5726161

Draft Genome Sequence of Pseudomonas nitroreducens Strain TX1, Which Degrades Nonionic Surfactants and Estrogen-Like Alkylphenols.

PubMed

Huang, Shir-Ly; Chen, Hsin; Hu, Anyi; Tuan, Nguyen Ngoc; Yu, Chang-Ping

2014-01-30

Pseudomonas nitroreducens TX1 ATCC PTA-6168 was isolated from rice field drainage in Taiwan. The bacterium is of special interest because of its capability to use nonionic surfactants (alkylphenol polyethoxylates) and estrogen-like compounds (4-t-octylphenol and 4-nonylphenol) as a sole carbon source. This is the first report on the genome sequence of P. nitroreducens.

Statistical optimization of medium components and growth conditions by response surface methodology to enhance phenol degradation by Pseudomonas putida.

PubMed

Annadurai, Gurusamy; Ling, Lai Yi; Lee, Jiunn-Fwu

2008-02-28

In this work, a four-level Box-Behnken factorial design was employed combining with response surface methodology (RSM) to optimize the medium composition for the degradation of phenol by pseudomonas putida (ATCC 31800). A mathematical model was then developed to show the effect of each medium composition and their interactions on the biodegradation of phenol. Response surface method was using four levels like glucose, yeast extract, ammonium sulfate and sodium chloride, which also enabled the identification of significant effects of interactions for the batch studies. The biodegradation of phenol on Pseudomonas putida (ATCC 31800) was determined to be pH-dependent and the maximum degradation capacity of microorganism at 30 degrees C when the phenol concentration was 0.2 g/L and the pH of the solution was 7.0. Second order polynomial regression model was used for analysis of the experiment. Cubic and quadratic terms were incorporated into the regression model through variable selection procedures. The experimental values are in good agreement with predicted values and the correlation coefficient was found to be 0.9980.

Synthesis and photophysical characterizations of thermal-stable naphthalene benzimidazoles.

PubMed

Erten-Ela, Sule; Ozcelik, Serdar; Eren, Esin

2011-07-01

Microwave-assisted synthesis, photophysical and electrochemical properties of thermal-stable naphthalene benzimidazoles and naphthalimides are studied in this paper. Microwave-assisted synthesis of naphthalene benzimidazoles provide higher yields than the conventional thermal synthesis. Comparative photophysical properties of naphthalene benzimidazoles and naphthalimides are revealed that conjugation of electron-donating group onto naphthalimide moiety increases fluorescence quantum yields. Fluorophore-solvent interactions are also investigated using Lippert-Mataga equation for naphthalimides and naphthalene benzimidazoles. Thermal stabilities of naphthalene benzimidazoles are better than naphthalimides due to increased aromaticity. The experimental E(LUMO) levels of naphthalene benzimidazoles are found to be between 3.15 and 3.28 eV. Therefore, naphthalene benzimidazole derivatives consisting of anchoring groups are promising materials in organic dye sensitized solar cells. © Springer Science+Business Media, LLC 2011

Experimental Electronic Spectroscopy of Two PAHs: Naphthalene and 2-METHYL Naphthalene

NASA Astrophysics Data System (ADS)

Friha, H.; Feraud, G.; Pino, T.; Brechignac, Ph.; Parneix, P.; Dhaoudi, Z.; Jaidane, N.; Galila, H.; Troy, T.; Schmidt, T.

2011-06-01

The presence of polycyclic aromatic hydrocarbons (PAHs) in the interstellar medium (ISM) was suggested in the mid-80's. Since then, their important role in the physico-chemical evolution of the ISM has been confirmed. Interstellar PAHs have been in particular proposed as possible carriers of some Diffuse Interstellar Bands (DIBs). These absorption bands are seen in the spectra of reddened stars from the visible to the near infrared and constitute a major astrophysical issue. Our purpose is to obtain electronic spectra of gas phase PAHs which will be used to probe their participation to the interstellar extinction curve from the visible (DIBs) to the UV (bump). For this goal PAHs cations represent an excellent set of target species. A new way of forming PAH+-Ar_n clusters cations has been implemented in the experimental set-up 'ICARE' at ISMO (Orsay) giving us the capability to measure the electronic spectra of cold PAH cations in the gas phase through the "Ar tagging" trick. Two molecules have been investigated in this way: naphthalene (C_1_0H_8) and 2- methyl naphthalene (C_1_1H_1_0). Clusters of naphthalene and (or 2-methyl-naphthalene) with Ar atoms are first formed in a supersonic jet, before being hit by a 281 nm laser beam which photo-ionizes the clusters which are then injected in a molecular beam through a skimmer. A tunable laser beam crossing downstream photo-dissociates the cations. The bare PAH fragments are detected using a Time-Of-Flight spectrometer while scanning the visible laser wavelength from 470 to 690 nm.

Microbial Degradation of Chlorogenic Acid by a Sphingomonas sp. Strain.

PubMed

Ma, Yuping; Wang, Xiaoyu; Nie, Xueling; Zhang, Zhan; Yang, Zongcan; Nie, Cong; Tang, Hongzhi

2016-08-01

In order to elucidate the metabolism of chlorogenic acid by environmental microbes, a strain of Sphingomonas sp. isolated from tobacco leaves was cultured under various conditions, and chlorogenic acid degradation and its metabolites were investigated. The strain converting chlorogenic acid was newly isolated and identified as a Sphingomonas sp. strain by 16S rRNA sequencing. The optimal conditions for growth and chlorogenic acid degradation were 37 °C and pH 7.0 with supplementation of 1.5 g/l (NH4)2SO4 as the nitrogen source and 2 g/l chlorogenic acid as the sole carbon source. The maximum chlorogenic acid tolerating capability for the strain was 5 g/l. The main metabolites were identified as caffeic acid, shikimic acid, and 3,4-dihydroxybenzoic acid based on gas chromatography-mass spectrometry analysis. The analysis reveals the biotransformation mechanism of chlorogenic acid in microbial cells isolated from the environment.

2-(Naphthalen-1-yl)-4-(naphthalen-1-yl­methyl­idene)-1,3-oxazol-5(4H)-one

PubMed Central

Gündoğdu, Cevher; Alp, Serap; Ergün, Yavuz; Tercan, Barış; Hökelek, Tuncer

2011-01-01

In the title compound, C24H15NO2, the oxazole ring is oriented at dihedral angles of 10.09 (4) and 6.04 (4)° with respect to the mean planes of the naphthalene ring systems, while the two naphthalene ring systems make a dihedral angle of 4.32 (3)°. Intra­molecular C—H⋯N hydrogen bonds link the oxazole N atom to the naphthalene ring systems. In the crystal, inter­molecular weak C—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. π–π contacts between the oxazole and naphthalene rings and between the naphthalene ring systems [centroid–centroid distances = 3.5947 (9) and 3.7981 (9) Å] may further stabilize the crystal structure. Three weak C—H⋯π inter­actions also occur. PMID:21754548

Characterization of Pseudomonas pathovars isolated from rosaceous fruit trees in East Algeria.

PubMed

Harzallah, D; Sadallah, S; Larous, L

2004-01-01

A survey of bacterial diseases due to Pseudomonas on rosaceous fruit trees was conducted. In forty two orchards located in the Constantine region ( East Algeria). Pseudomonas isolates were identified on the bases of their cultural and biochemical characteristics . A total of fifty nine phytopathogenic bacteria were isolated from diseased pome and stone fruit trees. Thirty one strains comparable to Pseudomonas syringae pv. syringae were isolated from cherry (Prunus avium L.), plum (P. domestica L.), apricot (P. armeniaca L.), almond (P. dulcis L.) and pear trees (Pirus communis L.); sixteen strains comparable to Pseudomonas syringae pv. morsprunorum were obtained from samples of cherry and plum. Twelve strains of Pseudomonas viridiflava were isolated from cherry, apricot and peach (Prunus persica L.).

Acute intravascular hemolysis and methemoglobinemia following naphthalene ball poisoning.

PubMed

Kapoor, Rajan; Suresh, P; Barki, Satish; Mishra, Mayank; Garg, M K

2014-09-01

Naphthalene (C10H8) is a natural component of fossil fuels such as petroleum, diesel and coal. The common consumer products made from naphthalene are moth repellents, in the form of mothballs or crystals, and toilet deodorant blocks. Major toxic effects of naphthalene are due to precipitation of acute intravascular hemolysis. Very few cases of naphthalene poisoning and its effects have been reported from India. We report a case of accidental naphthalene poisoning, who presented with intravascular hemolysis and methemoglobinemia.

Draft Genome Sequence of Pseudomonas nitroreducens Strain TX1, Which Degrades Nonionic Surfactants and Estrogen-Like Alkylphenols

PubMed Central

Chen, Hsin; Hu, Anyi; Tuan, Nguyen Ngoc

2014-01-01

Pseudomonas nitroreducens TX1 ATCC PTA-6168 was isolated from rice field drainage in Taiwan. The bacterium is of special interest because of its capability to use nonionic surfactants (alkylphenol polyethoxylates) and estrogen-like compounds (4-t-octylphenol and 4-nonylphenol) as a sole carbon source. This is the first report on the genome sequence of P. nitroreducens. PMID:24482523

Complete Genome Sequence of Pseudomonas fluorescens LBUM636, a Strain with Biocontrol Capabilities against Late Blight of Potato

PubMed Central

Morrison, Christopher K.; Novinscak, Amy; Gadkar, Vijay J.; Joly, David L.

2016-01-01

Herein provided is the full-genome sequence of Pseudomonas fluorescens LBUM636. This strain is a plant growth-promoting rhizobacterium (PGPR) which produces phenazine-1-carboxylic acid, an antibiotic involved in the biocontrol of numerous plant pathogens, including late blight of potato caused by the plant pathogen Phytophthora infestans. PMID:27231373

Role of the Pseudomonas quinolone signal (PQS) in sensitising Pseudomonas aeruginosa to UVA radiation.

PubMed

Pezzoni, Magdalena; Meichtry, Martín; Pizarro, Ramón A; Costa, Cristina S

2015-01-01

One of the main stress factors that bacteria face in the environment is solar ultraviolet-A (UVA) radiation, which leads to lethal effects through oxidative damage. The aim of this work was to investigate the role of 2-heptyl-3-hydroxi-4-quinolone (the Pseudomonas quinolone signal or PQS) in the response of Pseudomonas aeruginosa to UVA radiation. PQS is an intercellular quorum sensing signal associated to membrane vesicles which, among other functions, regulates genes related to iron acquisition, forms stable complexes with iron and participates in oxidative phenomena. UVA exposure of the wild-type PAO1 strain and a pqsA mutant unable to produce PQS revealed a sensitising role for this signal. Research into the mechanism involved in this phenomenon revealed that catalase, an essential factor in the UVA defence, is not related to PQS-mediated UVA sensitivity. Absorption of UVA by PQS produced its own photo-degradation, oxidation of the probe 2',7'- dichlorodihydrofluorescein and generation of singlet oxygen and superoxide anion, suggesting that this signal could be acting as an endogenous photosensitiser. The results presented in this study could explain the high sensitivity to UVA of P. aeruginosa when compared to enteric bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC.

PubMed

Oosterkamp, Margreet J; Boeren, Sjef; Atashgahi, Siavash; Plugge, Caroline M; Schaap, Peter J; Stams, Alfons J M

2015-06-01

Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In the proposed acetone degradation pathway, an acetone carboxylase converts acetone to acetoacetate, an AMP-dependent synthetase/ligase converts acetoacetate to acetoacetyl-CoA, and an acetyl-CoA acetyltransferase cleaves acetoacetyl-CoA to two acetyl-CoA. We also found a putative aldehyde dehydrogenase associated with acetone degradation. This enzyme functioned as a β-hydroxybutyrate dehydrogenase catalyzing the conversion of surplus acetoacetate to β-hydroxybutyrate that may be converted to the energy and carbon storage compound, poly-β-hydroxybutyrate. Accordingly, we confirmed the formation of poly-β-hydroxybutyrate in acetone-grown cells of strain BC. Our findings provide insight in nitrate-dependent acetone degradation that is activated by carboxylation of acetone. This will aid studies of similar pathways found in other microorganisms degrading acetone with nitrate or sulfate as electron acceptor. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

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.

RETRACTED: Aerobic degradation of 4-nitroaniline (4-NA) via novel degradation intermediates by Rhodococcus sp. strain FK48.

PubMed

Khan, Fazlurrahman; Pandey, Janmejay; Vikram, Surendra; Pal, Deepika; Cameotra, Swaranjit Singh

2013-06-15

An aerobic strain, Rhodococcus sp. strain FK48, capable of growing on 4-nitroaniline (4-NA) as the sole source of carbon, nitrogen, and energy has been isolated from enrichment cultures originating from contaminated soil samples. During growth studies with non- induced cells of FK48 catalyzed sequential denitrification (release of NO₂ substituent) and deamination (release of NH₂ substituent) of 4-NA. However, none of the degradation intermediates could be identified with growth studies. During resting cell studies, 4-NA-induced cells of strain FK48 transformed 4-NA via a previously unknown pathway which involved oxidative hydroxylation leading to formation of 4-aminophenol (4-AP). Subsequent degradation involved oxidated deamination of 4-AP and formation of 1,2,4-benzenetriol (BT) as the major identified terminal aromatic intermediate. Identification of these intermediates was ascertained by HPLC, and GC-MS analyses of the culture supernatants. 4-NA-induced cells of strain FK48 showed positive activity for 1,2,4-benzenetriol dioxygenase in spectrophotometric assay. This is the first conclusive study on aerobic microbial degradation of 4-NA and elucidation of corresponding metabolic pathway. Copyright © 2013 Elsevier B.V. All rights reserved.

Genome Sequence of the Electrogenic Petroleum-Degrading Thalassospira sp. Strain HJ

PubMed Central

Kiseleva, Larisa; Garushyants, Sofya K.; Briliute, Justina; Simpson, David J. W.; Goryanin, Igor

2015-01-01

We present the draft genome of the petroleum-degrading Thalassospira sp. strain HJ, isolated from tidal marine sediment. Knowledge of this genomic information will inform studies on electrogenesis and means to degrade environmental organic contaminants, including compounds found in petroleum. PMID:25977412

Degradation of organic pollutants by methane grown microbial consortia.

PubMed

Hesselsoe, Martin; Boysen, Susanne; Iversen, Niels; Jørgensen, Lars; Murrell, J Colin; McDonald, Ian; Radajewski, Stefan; Thestrup, Helle; Roslev, Peter

2005-10-01

Microbial consortia were enriched from various environmental samples with methane as the sole carbon and energy source. Selected consortia that showed a capacity for co-oxidation of naphthalene were screened for their ability to degrade methyl-tert-butyl-ether (MTBE), phthalic acid esters (PAE), benzene, xylene and toluene (BTX). MTBE was not removed within 24 h by any of the consortia examined. One consortium enriched from activated sludge ("AAE-A2"), degraded PAE, including (butyl-benzyl)phthalate (BBP), and di-(butyl)phthalate (DBP). PAE have not previously been described as substrates for methanotrophic consortia. The apparent Km and Vmax for DBP degradation by AAE-A2 at 20 degrees C was 3.1 +/- 1.2 mg l(-1) and 8.7 +/- 1.1 mg DBP (g protein x h)(-1), respectively. AAE-A2 also showed fast degradation of BTX (230 +/- 30 nmol benzene (mg protein x h)(-1) at 20 degrees C). Additionally, AAE-A2 degraded benzene continuously for 2 weeks. In contrast, a pure culture of the methanotroph Methylosinus trichosporium OB3b ceased benzene degradation after only 2 days. Experiments with methane mono-oxygenase inhibitors or competitive substrates suggested that BTX degradation was carried out by methane-oxidizing bacteria in the consortium, whereas the degradation of PAE was carried out by non-methanotrophic bacteria co-existing with methanotrophs. The composition of the consortium (AAE-A2) based on polar lipid fatty acid (PLFA) profiles showed dominance of type II methanotrophs (83-92% of biomass). Phylogeny based on a 16S-rRNA gene clone library revealed that the dominating methanotrophs belonged to Methylosinus/Methylocystis spp. and that members of at least 4 different non-methanotrophic genera were present (Pseudomonas, Flavobacterium, Janthinobacterium and Rubivivax).

Genetically enhanced cellulase production in Pseudomonas cellulosa using recombinant DNA technology

DOEpatents

Dees, H. Craig

1999-01-01

An enhanced strain of Pseudomonas celllulosa was obtained by introducing a recombinant genetic construct comprising a heterologous cellulase gene operably connected to a promoter into ATCC 55702, mutagenizing the transformants by treatment with MNNG, and selecting a high cellulase producing transformant. The transformant, designated Pseudomonas cellulosa ATCC XXXX, exhibits enhanced levels of cellulase production relative to the untransformed Pseudomonas cellulosa strain #142 ATCC 55702.

[Isolation, identification and characterization of a diethylstilbestrol-degrading bacterial strain Serratia sp].

PubMed

Xu, Ran-Fang; Sun, Min-Xia; Liu, Juan; Wang, Hong; Li, Xin; Zhu, Xue-Zhu; Ling, Wan-Ting

2014-08-01

Utilizing the diethylstilbestrol (DES)-degrading bacteria to biodegrade DES is a most reliable technique for cleanup of DES pollutants from the environment. However, little information is available heretofore on the isolation of DES-degrading bacteria and their DES removal performance in the environment. A novel bacterium capable of degrading DES was isolated from the activated sludge of a wastewater treatment plant. According to its morphology, physiochemical characteristics, and 16S rDNA sequence analysis, this strain was identified as Serratia sp.. The strain was an aerobic bacterium, and it could degrade 68.3% of DES (50 mg x L(-1)) after culturing for 7 days at 30 degrees C, 150 r x min(-1) in shaking flasks. The optimal conditions for DES biodegradation by the obtained strain were 30 degrees C, 40-60 mg x L(-1) DES, pH 7.0, 5% of inoculation volume, 0 g x L(-1) of added NaCl, and 10 mL of liquid medium volume in 100 mL flask.

Genomic characterisation of clinical and environmental Pseudomonas putida group strains and determination of their role in the transfer of antimicrobial resistance genes to Pseudomonas aeruginosa.

PubMed

Peter, Silke; Oberhettinger, Philipp; Schuele, Leonard; Dinkelacker, Ariane; Vogel, Wichard; Dörfel, Daniela; Bezdan, Daniela; Ossowski, Stephan; Marschal, Matthias; Liese, Jan; Willmann, Matthias

2017-11-10

Pseudomonas putida is a Gram-negative, non-fermenting bacterium frequently encountered in various environmental niches. P. putida rarely causes disease in humans, though serious infections and outbreaks have been reported from time to time. Some have suggested that P. putida functions as an exchange platform for antibiotic resistance genes (ARG), and thus represents a serious concern in the spread of ARGs to more pathogenic organisms within a hospital. Though poorly understood, the frequency of ARG exchange between P. putida and the more virulent Pseudomonas aeruginosa and its clinical relevance are particularly important for designing efficient infection control strategies, such as deciding whether high-risk patients colonized with a multidrug resistant but typically low pathogenic P. putida strain should be contact isolated or not. In this study, 21,373 screening samples (stool, rectal and throat swab) were examined to determine the presence of P. putida in a high-risk group of haemato-oncology patients during a 28-month period. A total of 89 P. putida group strains were isolated from 85 patients, with 41 of 89 (46.1%) strains harbouring the metallo-beta-lactamase gene bla VIM . These 41 clinical isolates, plus 18 bla VIM positive environmental P. putida isolates, and 17 bla VIM positive P. aeruginosa isolates, were characterized by whole genome sequencing (WGS). We constructed a maximum-likelihood tree to separate the 59 bla VIM positive P. putida group strains into eight distinct phylogenetic clusters. Bla VIM-1 was present in 6 clusters while bla VIM-2 was detected in 4 clusters. Five P. putida group strains contained both, bla VIM-1 and bla VIM-2 genes. In contrast, all P. aeruginosa strains belonged to a single genetic cluster and contained the same ARGs. Apart from bla VIM-2 and sul genes, no other ARGs were shared between P. aeruginosa and P. putida. Furthermore, the bla VIM-2 gene in P. aeruginosa was predicted to be only chromosomally located. These data

Tomato seed and root exudate sugars: composition, utilization by Pseudomonas biocontrol strains and role in rhizosphere colonization.

PubMed

Lugtenberg, B J; Kravchenko, L V; Simons, M

1999-10-01

The role of tomato seed and root exudate sugars as nutrients for Pseudomonas biocontrol bacteria was studied. To this end, the major exudate sugars of tomato seeds, seedlings and roots were identified and quantified using high-performance liquid chromatographic (HPLC) analysis. Glucose, fructose and maltose were present in all studied growth stages of the plant, but the ratios of these sugars were strongly dependent on the developmental stage. In order to study the putative role of exudate sugar utilization in rhizosphere colonization, two approaches were adopted. First, after co-inoculation on germinated tomato seeds, the root-colonizing ability of the efficient root-colonizing P. fluorescens strain WCS365 in a gnotobiotic quartz sand-plant nutrient solution system was compared with that of other Pseudomonas biocontrol strains. No correlation was observed between the colonizing ability of a strain and its ability to use the major exudate sugars as the only carbon and energy source. Secondly, a Tn5lacZ mutant of P. fluorescens strain WCS365, strain PCL1083, was isolated, which is impaired in its ability to grow on simple sugars, including those found in exudate. The mutation appeared to reside in zwf, which encodes glucose-6-phosphate dehydrogenase. The mutant grows as well as the parental strain on other media, including tomato root exudate. After inoculation of germinated sterile tomato seeds, the mutant cells reached the same population levels at the root tip as the wild-type strain, both alone and in competition, indicating that the ability to use exudate sugars does not play a major role in tomato root colonization, despite the fact that sugars have often been reported to represent the major exudate carbon source. This conclusion is supported by the observation that the growth of mutant PCL1083 in vitro is inhibited by glucose, a major exudate sugar, at a concentration of 0.001%, which indicates that the glucose concentration in the tomato rhizosphere is very

Modeling of competitive mutualistic relationships. Application to cellulose degradation by Streptomyces sp. strains.

PubMed

Thierie, Jacques; Penninckx, Michel J

2007-12-01

A "cascade" model depicts microbial degradation of a complex nutrient/substrate through a succession of intermediate compounds. Each stage is characterized by a particular species producing a typical degradation enzyme induced by its own degradation product. The final compound of the cascade consists of a single assimilable substrate used by all species. This results in a competition situation, whereas the contribution of all strains to the production of a complete set of efficient enzymes generates a mutualistic relationship. The model was shown to be appropriate to describe degradation of cellulose by a consortium of Streptomyces sp. strains. The simplicity and the model capacity for generalization are promising and could be used for various degradation processes both at laboratory and environmental scales.

Possible initial steps in the catabolism of 1,2-diphenylethanone (deoxybenzoin) by Pseudomonas fluorescens DB-5.

PubMed Central

Hinrichsen, P; Vicuña, R

1993-01-01

A natural bacterial strain, identified as Pseudomonas fluorescens DB-5, was isolated in enrichment cultures containing 1,2-diphenylethanone as the only source of carbon and energy. On the basis of characteristic features observed in the mass spectra of degradation intermediates, it is proposed that metabolism of 1,2-diphenylethanone is initiated by two hydroxylations on the benzyl ring. Phenol, presumably arising from the benzoyl ring, was transiently detected as a catabolic intermediate. PMID:8250568

A Novel Aerobic Degradation Pathway for Thiobencarb Is Initiated by the TmoAB Two-Component Flavin Mononucleotide-Dependent Monooxygenase System in Acidovorax sp. Strain T1

PubMed Central

Chu, Cui-Wei; Liu, Bin; Li, Na; Yao, Shi-Gang; Cheng, Dan; Zhao, Jia-Dong; Qiu, Ji-Guo; Yan, Xin; He, Jian

2017-01-01

ABSTRACT Thiobencarb is a thiocarbamate herbicide used in rice paddies worldwide. Microbial degradation plays a crucial role in the dissipation of thiobencarb in the environment. However, the physiological and genetic mechanisms underlying thiobencarb degradation remain unknown. In this study, a novel thiobencarb degradation pathway was proposed in Acidovorax sp. strain T1. Thiobencarb was oxidized and cleaved at the C—S bond, generating diethylcarbamothioic S-acid and 4-chlorobenzaldehyde (4CDA). 4CDA was then oxidized to 4-chlorobenzoic acid (4CBA) and hydrolytically dechlorinated to 4-hydroxybenzoic acid (4HBA). The identification of catabolic genes suggested further hydroxylation to protocatechuic acid (PCA) and finally degradation through the protocatechuate 4,5-dioxygenase pathway. A novel two-component monooxygenase system identified in the strain, TmoAB, was responsible for the initial catabolic reaction. TmoA shared 28 to 32% identity with the oxygenase components of pyrimidine monooxygenase from Agrobacterium fabrum, alkanesulfonate monooxygenase from Pseudomonas savastanoi, and dibenzothiophene monooxygenase from Rhodococcus sp. TmoB shared 25 to 37% identity with reported flavin reductases and oxidized NADH but not NADPH. TmoAB is a flavin mononucleotide (FMN)-dependent monooxygenase and catalyzed the C—S bond cleavage of thiobencarb. Introduction of tmoAB into cells of the thiobencarb degradation-deficient mutant T1m restored its ability to degrade and utilize thiobencarb. A dehydrogenase gene, tmoC, was located 7,129 bp downstream of tmoAB, and its transcription was clearly induced by thiobencarb. The purified TmoC catalyzed the dehydrogenation of 4CDA to 4CBA using NAD+ as a cofactor. A gene cluster responsible for the complete 4CBA metabolic pathway was also cloned, and its involvement in thiobencarb degradation was preliminarily verified by transcriptional analysis. IMPORTANCE Microbial degradation is the main factor in thiobencarb dissipation

A Novel Aerobic Degradation Pathway for Thiobencarb Is Initiated by the TmoAB Two-Component Flavin Mononucleotide-Dependent Monooxygenase System in Acidovorax sp. Strain T1.

PubMed

Chu, Cui-Wei; Liu, Bin; Li, Na; Yao, Shi-Gang; Cheng, Dan; Zhao, Jia-Dong; Qiu, Ji-Guo; Yan, Xin; He, Qin; He, Jian

2017-12-01

Thiobencarb is a thiocarbamate herbicide used in rice paddies worldwide. Microbial degradation plays a crucial role in the dissipation of thiobencarb in the environment. However, the physiological and genetic mechanisms underlying thiobencarb degradation remain unknown. In this study, a novel thiobencarb degradation pathway was proposed in Acidovorax sp. strain T1. Thiobencarb was oxidized and cleaved at the C-S bond, generating diethylcarbamothioic S -acid and 4-chlorobenzaldehyde (4CDA). 4CDA was then oxidized to 4-chlorobenzoic acid (4CBA) and hydrolytically dechlorinated to 4-hydroxybenzoic acid (4HBA). The identification of catabolic genes suggested further hydroxylation to protocatechuic acid (PCA) and finally degradation through the protocatechuate 4,5-dioxygenase pathway. A novel two-component monooxygenase system identified in the strain, TmoAB, was responsible for the initial catabolic reaction. TmoA shared 28 to 32% identity with the oxygenase components of pyrimidine monooxygenase from Agrobacterium fabrum , alkanesulfonate monooxygenase from Pseudomonas savastanoi , and dibenzothiophene monooxygenase from Rhodococcus sp. TmoB shared 25 to 37% identity with reported flavin reductases and oxidized NADH but not NADPH. TmoAB is a flavin mononucleotide (FMN)-dependent monooxygenase and catalyzed the C-S bond cleavage of thiobencarb. Introduction of tmoAB into cells of the thiobencarb degradation-deficient mutant T1m restored its ability to degrade and utilize thiobencarb. A dehydrogenase gene, tmoC , was located 7,129 bp downstream of tmoAB , and its transcription was clearly induced by thiobencarb. The purified TmoC catalyzed the dehydrogenation of 4CDA to 4CBA using NAD + as a cofactor. A gene cluster responsible for the complete 4CBA metabolic pathway was also cloned, and its involvement in thiobencarb degradation was preliminarily verified by transcriptional analysis. IMPORTANCE Microbial degradation is the main factor in thiobencarb dissipation in soil

Isolation and characterization of two crude oil-degrading fungi strains from Rumaila oil field, Iraq.

PubMed

Al-Hawash, Adnan B; Alkooranee, Jawadayn T; Abbood, Hayder A; Zhang, Jialong; Sun, Jin; Zhang, Xiaoyu; Ma, Fuying

2018-03-01

Among four crude oil-degrading fungi strains that were isolated from a petroleum-polluted area in the Rumaila oil field, two fungi strains showed high activity in aliphatic hydrocarbon degradation. ITS sequencing and analysis of morphological and biochemical characteristics identified these strains as Penicillium sp. RMA1 and RMA2. Gravimetric and gas chromatography analysis of the crude oil remaining in the culture medium after 14 days of incubation at 30 °C showed that RMA1 and RMA2 degraded the crude oil by 57% and 55%, respectively. These strains reduced surface tension when cultured on crude oil (1% v/v) and exhibited a cell surface hydrophobicity of more than 70%. These results suggested that RMA1 and RMA2 performed effective crude oil-degrading activity and crude oil emulsification. In conclusion, these fungal strains can be used in bioremediation process and oil pollution reduction in aquatic ecosystems.

Comparison of arbitrarily primed PCR and macrorestriction (pulsed-field gel electrophoresis) typing of Pseudomonas aeruginosa strains from cystic fibrosis patients.

PubMed Central

Kersulyte, D; Struelens, M J; Deplano, A; Berg, D E

1995-01-01

Arbitrarily primed PCR fingerprinting was carried out on 43 Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients. Seventeen major groups of strains that coincided with groups also distinguished by macrorestriction (pulsed-field gel electrophoresis) typing were identified. Our results illustrated that a CF patient can carry more than one strain and can carry a given strain for long periods of time and that strains can evolve by changes in drug resistance or other phenotypic traits during long-term colonization. The arbitrarily primed PCR method is recommended for first-pass screening of P. aeruginosa isolates from CF patients, especially when many strains are to be typed, because of its sensitivity and efficiency. PMID:7559985

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

Anaerobic Degradation of Benzene, Toluene, Ethylbenzene, and Xylene Compounds by Dechloromonas Strain RCB

PubMed Central

Chakraborty, Romy; O'Connor, Susan M.; Chan, Emily; Coates, John D.

2005-01-01

Dechloromonas strain RCB has been shown to be capable of anaerobic degradation of benzene coupled to nitrate reduction. As a continuation of these studies, the metabolic versatility and hydrocarbon biodegradative capability of this organism were investigated. The results of these revealed that in addition to nitrate, strain RCB could alternatively degrade benzene both aerobically and anaerobically with perchlorate or chlorate [(per)chlorate] as a suitable electron acceptor. Furthermore, with nitrate as the electron acceptor, strain RCB could also utilize toluene, ethylbenzene, and all three isomers of xylene (ortho-, meta-, and para-) as electron donors. While toluene and ethylbenzene were completely mineralized to CO2, strain RCB did not completely mineralize para-xylene but rather transformed it to some as-yet-unidentified metabolite. Interestingly, with nitrate as the electron acceptor, strain RCB degraded benzene and toluene concurrently when the hydrocarbons were added as a mixture and almost 92 μM total hydrocarbons were oxidized within 15 days. The results of these studies emphasize the unique metabolic versatility of this organism, highlighting its potential applicability to bioremediative technologies. PMID:16332859

Genome Sequence of the Electrogenic Petroleum-Degrading Thalassospira sp. Strain HJ.

PubMed

Kiseleva, Larisa; Garushyants, Sofya K; Briliute, Justina; Simpson, David J W; Cohen, Michael F; Goryanin, Igor

2015-05-14

We present the draft genome of the petroleum-degrading Thalassospira sp. strain HJ, isolated from tidal marine sediment. Knowledge of this genomic information will inform studies on electrogenesis and means to degrade environmental organic contaminants, including compounds found in petroleum. Copyright © 2015 Kiseleva et al.

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.

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.

A Mycobacterium Strain with Extended Capacities for Degradation of Gasoline Hydrocarbons

PubMed Central

Solano-Serena, Floriane; Marchal, Rémy; Casarégola, Serge; Vasnier, Christelle; Lebeault, Jean-Michel; Vandecasteele, Jean-Paul

2000-01-01

A bacterial strain (strain IFP 2173) was selected from a gasoline-polluted aquifer on the basis of its capacity to use 2,2,4-trimethylpentane (isooctane) as a sole carbon and energy source. This isolate, the first isolate with this capacity to be characterized, was identified by 16S ribosomal DNA analysis, and 100% sequence identity with a reference strain of Mycobacterium austroafricanum was found. Mycobacterium sp. strain IFP 2173 used an unusually wide spectrum of hydrocarbons as growth substrates, including n-alkanes and multimethyl-substituted isoalkanes with chains ranging from 5 to 16 carbon atoms long, as well as substituted monoaromatic hydrocarbons. It also attacked ethers, such as methyl t-butyl ether. During growth on gasoline, it degraded 86% of the substrate. Our results indicated that strain IFP 2173 was capable of degrading 3-methyl groups, possibly by a carboxylation and deacetylation mechanism. Evidence that it attacked the quaternary carbon atom structure by an as-yet-undefined mechanism during growth on 2,2,4-trimethylpentane and 2,2-dimethylpentane was also obtained. PMID:10831416

Biodegradation of nicotine by a novel nicotine-degrading bacterium, Pseudomonas plecoglossicida TND35 and its new biotransformation intermediates.

PubMed

Raman, Gurusamy; Mohan, KasiNadar; Manohar, Venkat; Sakthivel, Natarajan

2014-02-01

Tobacco wastes that contain nicotine alkaloids are harmful to human health and the environment. In the investigation, a novel nicotine-biodegrading bacterium TND35 was isolated and identified as Pseudomonas plecoglossicida on the basis of phenotypic, biochemical characteristics and 16S rRNA sequence homology. We have studied the nicotine biodegradation potential of strain TND35 by detecting the intermediate metabolites using an array of approaches such as HPLC, GC-MS, NMR and FT-IR. Biotransformation metabolites, N-methylmyosmine, 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB) and other three new intermediate metabolites namely, 3,5-bis (1-methylpyrrolidin-2-yl) pyridine, 2,3-dihydro-1-methyl-5-(pyridin-3-yl)-1H-pyrrol-2-ol and 5-(pyridin-3-yl)-1H-pyrrol-2(3H)-one have been identified. Interestingly, these intermediate metabolites suggest that the strain TND35 employs a novel nicotine biodegradation pathway, which is different from the reported pathways of Aspergillus oryzae 112822, Arthrobacter nicotinovorans pAO1, Agrobacterium tumefaciens S33 and other species of Pseudomonas. The metabolite, HPB reported in this study can also be used as biochemical marker for tobacco related cancer studies.

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.

Degradation pathway of the naphthalene azo dye intermediate 1-diazo-2- naphthol-4-sulfonic acid using Fenton's reagent.

PubMed

Zhu, Nanwen; Gu, Lin; Yuan, Haiping; Lou, Ziyang; Wang, Liang; Zhang, Xin

2012-08-01

Degradation of naphthalene dye intermediate 1-diazo-2- naphthol-4-sulfonic acid (1,2,4-Acid) by Fenton process has been studied in depth for the purpose of learning more about the reactions involved in the oxidation of 1,2,4-Acid. During 1,2,4-Acid oxidation, the solution color initially takes on a dark red, then to dark black associated with the formation of quinodial-type structures, and then goes to dark brown and gradually disappears, indicating a fast degradation of azo group. The observed color changes of the solution are a result of main reaction intermediates, which can be an indicator of the level of oxidization reached. Nevertheless, complete TOC removal is not accomplished, in accordance with the presence of resistant carboxylic acids at the end of the reaction. The intermediates generated along the reaction time have been identified and quantified. UPLC-(ESI)-TOF-HRMS analysis allows the detection of 19 aromatic compounds of different size and complexity. Some of them share the same accurate mass but appear at different retention time, evidencing their different molecular structures. Heteroatom oxidation products like SO(4)(2-) have also been quantified and explanations of their release are proposed. Short-chain carboxylic acids are detected at long reaction time, as a previous step to complete the process of dye mineralization. Finally, considering all the findings of the present study and previous related works, the evolution from the original 1,2,4-Acid to the final products is proposed in a general reaction scheme. Copyright © 2012 Elsevier Ltd. All rights reserved.

Research on Identification and Screen of Microbial Desulfurization Strains for Petroleum

NASA Astrophysics Data System (ADS)

Xiaojuan, Tian; Lingtian, Tang; Li'e, Peng; Xinghong, Li

The oil-contaminated soil sample was acquired from Shengli Oilfield and Jidong Oilfield and cultured with enrichment technology. Then 21 desulfurization strains were separated from the sample, from which a high efficiency desulfurization strain TV9704 was selected. The strain could neither grow with n-dodecane, n-hexadecane, liquid paraffin, naphthalene or diesel as a carbon source and energy source, nor obviously reduce oil combustion value. It could use thiophene or dibenzothiophene (DBT) as the sole sulfur source. In the experiment, the concentrations of thiophene and DBT were measured by UV spectrophotometer. After being cultured in the culture medium with an initial concentration of 63.2 mmol/L respectively for 48 h and 144 h, the degradation rates of the strain TV9704 on thiophene were 39.0% and 63.8%; the DBT with an initial concentration of 2.7 mmol/L was degraded by 1.46 mmol/L after cultured for 72 h. When sodium acetate and glycerol were chosen as carbon source, the ethanol could enhance the degradation rate of TV9704 on DBT significantly. Strain TV9704 was identified by China Industrial Culture Collection Center (CICC) as a Bacillus sp., Gram-positive, obligate aerobic, which forms a circular orange colony on the nutrition gravy plate. The 16SrDNA gene sequencing test and analysis was carried out on strain TV9704, finding that its homologies with the most similar species Bacillus aquimaris and Bacillus marisflavi were 99.2% and 98.2% respectively, but a larger difference existed between their cell morphological characteristics and physiological and biochemical characteristics, therefore strain TV9704 may be a new species because it was impossible to be categorized to any population.

Degradation of phenol and TCE using suspended and chitosan-bead immobilized Pseudomonas putida.

PubMed

Chen, Yan-Min; Lin, Tsair-Fuh; Huang, Chih; Lin, Jui-Che; Hsieh, Feng-Ming

2007-09-30

The degradability of phenol and trichloroethene (TCE) by Pseudomonas putida BCRC 14349 in both suspended culture and immobilized culture systems are investigated. Chitosan beads at a size of about 1-2mm were employed to encapsulate the P. putida cells, becoming an immobilized culture system. The phenol concentration was controlled at 100 mg/L, and that of TCE was studied from 0.2 to 20 mg/L. The pH, between 6.7 and 10, did not affect the degradation of either phenol or TCE in the suspended culture system. However, it was found to be an important factor in the immobilized culture system in which the only significant degradation was observed at pH >8. This may be linked to the surface properties of the chitosan beads and its influence on the activity of the bacteria. The transfer yield of TCE on a phenol basis was almost the same for the suspended and immobilized cultures (0.032 mg TCE/mg phenol), except that these yields occurred at different TCE concentrations. The transfer yield at a higher TCE concentration for the immobilized system suggested that the cells immobilized in carriers can be protected from harsh environmental conditions. For kinetic rate interpretation, the Monod equation was employed to describe the degradation rates of phenol, while the Haldane's equation was used for TCE degradation. Based on the kinetic parameters obtained from the two equations, the rate for the immobilized culture systems was only about 1/6 to that of the suspended culture system for phenol degradation, and was about 1/2 for TCE degradation. The slower kinetics observed for the immobilized culture systems was probably due to the slow diffusion of substrate molecules into the beads. However, compared with the suspended cultures, the immobilized cultures may tolerate a higher TCE concentration as much less inhibition was observed and the transfer yield occurred at a higher TCE concentration.

Aerobic TCE degradation by encapsulated toluene-oxidizing bacteria, Pseudomonas putida and Bacillus spp.

PubMed

Kim, Seungjin; Bae, Wookeun; Hwang, Jungmin; Park, Jaewoo

2010-01-01

The degradation rates of toluene and trichloroethylene (TCE) by Pseudomonas putida and Bacillus spp. that were encapsulated in polyethylene glycol (PEG) polymers were evaluated in comparison with the results of exposure to suspended cultures. PEG monomers were polymerized together with TCE-degrading microorganisms, such that the cells were encapsulated in and protected by the matrices of the PEG polymers. TCE concentrations were varied from 0.1 to 1.5 mg/L. In the suspended cultures of P. putida, the TCE removal rate decreased as the initial TCE concentration increased, revealing TCE toxicity or a limitation of reducing power, or both. When the cells were encapsulated, an initial lag period of about 10-20 h was observed for toluene degradation. Once acclimated, the encapsulated P. putida cultures were more tolerant to TCE at an experimental range of 0.6-1.0 mg/L and gave higher transfer efficiencies (mass TCE transformed/mass toluene utilized). When the TCE concentration was low (e.g., 0.1 mg/L) the removal of TCE per unit mass of cells (specific removal) was significantly lower, probably due to a diffusion limitation into the PEG pellet. Encapsulated Bacillus spp. were able to degrade TCE cometabolically. The encapsulated Bacillus spp. gave significantly higher values than did P. putida in the specific removal and the transfer efficiency, particularly at relatively high TCE concentration of approximately 1.0±0.5 mg/L. The transfer efficiency by encapsulated Bacillus spp. in this study was 0.27 mgTCE/mgToluene, which was one to two orders of magnitude greater than the reported values.

Evaluation of five selective media for the detection of Pseudomonas aeruginosa using a strain panel from clinical, environmental and industrial sources.

PubMed

Weiser, Rebecca; Donoghue, Denise; Weightman, Andrew; Mahenthiralingam, Eshwar

2014-04-01

Isolation and correct identification of the opportunistic pathogen and industrial contaminant Pseudomonas aeruginosa are very important and numerous selective media are available for this purpose. A novel comparison of five selective media having positive (acetamide-based agars), negative (Pseudomonas CN selective agar [Oxoid Ltd.] and Pseudomonas Isolation agar [Sigma-Aldrich Company Ltd.]) and chromogenic (chromID® P. aeruginosa [bioMérieux]) selection strategies was performed using a systematically designed bacterial test panel (58 P. aeruginosa and 90 non-P. aeruginosa strains including those commonly misidentified as P. aeruginosa by culture-dependent techniques). Standardised inocula were added to the selective media and the results were recorded after 24 and 72h. After 72h of incubation at 37°C chromID® P. aeruginosa displayed the highest specificity (70%) and had good sensitivity (95%), although the sensitivity was negatively impacted by the large variation in colour of P. aeruginosa colonies, which hampered interpretation. Both media containing inhibitory selective agents performed very similarly, both having 100% sensitivity and a specificity of approximately 30%. Raising the incubation temperature to 42°C increased the specificity of Pseudomonas CN selective agar and Pseudomonas isolation agar (61% and 47% respectively after 72h), but increased the number of false positives encountered with the chromogenic medium, decreasing its specificity to 68% after 72h. Growth on the acetamide agars was weak for all strains and it was often difficult to determine whether true growth had occurred. This, compounded by the low specificity of the acetamide agars (<26%), suggested they were less suitable for application to clinical or industrial settings without further modification. Overall, the chromogenic agar was the most selective but further consideration is required to optimise interpretation of results. Copyright © 2014 Elsevier B.V. All rights reserved.

Quantification of biodegradation for o-xylene and naphthalene using first order decay models, Michaelis-Menten kinetics and stable carbon isotopes.

PubMed

Blum, Philipp; Hunkeler, Daniel; Weede, Matthias; Beyer, Christof; Grathwohl, Peter; Morasch, Barbara

2009-04-01

At a former wood preservation plant severely contaminated with coal tar oil, in situ bulk attenuation and biodegradation rate constants for several monoaromatic (BTEX) and polyaromatic hydrocarbons (PAH) were determined using (1) classical first order decay models, (2) Michaelis-Menten degradation kinetics (MM), and (3) stable carbon isotopes, for o-xylene and naphthalene. The first order bulk attenuation rate constant for o-xylene was calculated to be 0.0025 d(-1) and a novel stable isotope-based first order model, which also accounted for the respective redox conditions, resulted in a slightly smaller biodegradation rate constant of 0.0019 d(-1). Based on MM-kinetics, the o-xylene concentration decreased with a maximum rate of k(max)=0.1 microg/L/d. The bulk attenuation rate constant of naphthalene retrieved from the classical first order decay model was 0.0038 d(-1). The stable isotope-based biodegradation rate constant of 0.0027 d(-1) was smaller in the reduced zone, while residual naphthalene in the oxic part of the plume further downgradient was degraded at a higher rate of 0.0038 d(-1). With MM-kinetics a maximum degradation rate of k(max)=12 microg/L/d was determined. Although best fits were obtained by MM-kinetics, we consider the carbon stable isotope-based approach more appropriate as it is specific for biodegradation (not overall attenuation) and at the same time accounts for the dominant electron-accepting process. For o-xylene a field based isotope enrichment factor epsilon(field) of -1.4 could be determined using the Rayleigh model, which closely matched values from laboratory studies of o-xylene degradation under sulfate-reducing conditions.

Biotransformations of 2-Methylisoborneol by Camphor-Degrading Bacteria ▿

PubMed Central

Eaton, Richard W.; Sandusky, Peter

2009-01-01

Many camphor-degrading bacteria that are able to transform 2-methylisoborneol (2-MIB) have been identified. Three of these strains have been examined in detail. Rhodococcus ruber T1 metabolizes camphor through 6-hydroxycamphor but converts 2-MIB to 3-hydroxy-2-MIB. Pseudomonas putida G1, which metabolizes camphor through 5-hydroxycamphor, converts MIB primarily to 6-hydroxy-2-MIB. Rhodococcus wratislaviensis DLC-cam converts 2-MIB through 5-hydroxy-2-MIB to 5-keto-2-MIB. Together, these three strains produce metabolites resulting from hydroxylation at all of the three available secondary carbons on the six-member ring of 2-MIB. PMID:19060161

Photodynamic inactivation of antibiotic resistant strain of Pseudomonas aeruginosa in vivo

NASA Astrophysics Data System (ADS)

Hashimoto, M. C. E.; Toffoli, D. J.; Prates, R. A.; Courrol, Lilia C.; Ribeiro, M. S.

2009-06-01

Burns are frequently contamined by pathogenic microorganisms and the widespread occurrence of antibiotic resistant strains of Pseudomonas aeruginosa in hospitals is a matter of growing concern. Hypocrellin B (HB) is a new generation photosensitizer extracted from the fungus Hypocrella bambusae with absorption bands at 460, 546 and 584 nm. Lanthanide ions change the HB molecular structure and a red shift in the absorption band is observed as well as an increase in the singlet oxygen quantum yield. In this study, we report the use of HB:La+3 to kill resistant strain of P. aeruginosa infected burns. Burns were produced on the back of mice and wounds were infected subcutaneously with 1x109 cfu/mL of P. aeruginosa. Three-hours after inoculation, the animals were divided into 4 groups: control, HB:La+3, blue LED and HB:La+3+blue LED. PDT was performed using 10μM HB:La+3 and 500mW light-emitting diode (LED) emitting at λ=470nm+/-20nm during 120s. The animals of all groups were killed and the infected skin was removed for bacterial counting. Mice with photosensitizer alone, light alone or untreated infected wounds presented 1x108 cfu/g while mice PDT-treated showed a reduction of 2 logs compared to untreated control. These results suggest that HB:La+3 associated to blue LED is effective in diminishing antibiotic resistant strain P. aeruginosa in infected burns.

Effect of Nitrogen Source on Growth and Trichloroethylene Degradation by Methane-Oxidizing Bacteria

PubMed Central

Chu, Kung-Hui; Alvarez-Cohen, Lisa

1998-01-01

The effect of nitrogen source on methane-oxidizing bacteria with respect to cellular growth and trichloroethylene (TCE) degradation ability were examined. One mixed chemostat culture and two pure type II methane-oxidizing strains, Methylosinus trichosporium OB3b and strain CAC-2, which was isolated from the chemostat culture, were used in this study. All cultures were able to grow with each of three different nitrogen sources: ammonia, nitrate, and molecular nitrogen. Both M. trichosporium OB3b and strain CAC-2 showed slightly lower net cellular growth rates and cell yields but exhibited higher methane uptake rates, levels of poly-β-hydroxybutyrate (PHB) production, and naphthalene oxidation rates when grown under nitrogen-fixing conditions. The TCE-degrading ability of each culture was measured in terms of initial TCE oxidation rates and TCE transformation capacities (mass of TCE degraded/biomass inactivated), measured both with and without external energy sources. Higher initial TCE oxidation rates and TCE transformation capacities were observed in nitrogen-fixing mixed, M. trichosporium OB3b, and CAC-2 cultures than in nitrate- or ammonia-supplied cells. TCE transformation capacities were found to correlate with cellular PHB content in all three cultures. The results of this study suggest that the nitrogen-fixing capabilities of methane-oxidizing bacteria can be used to select for high-activity TCE degraders for the enhancement of bioremediation in fixed-nitrogen-limited environments. PMID:9726896

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.

Simultaneous enhancement of phenolic compound degradations by Acinetobacter strain V2 via a step-wise continuous acclimation process.

PubMed

Lin, Johnson; Sharma, Vikas; Milase, Ridwaan; Mbhense, Ntuthuko

2016-06-01

Phenol degradation enhancement of Acinetobacter strain V2 by a step-wise continuous acclimation process was investigated. At the end of 8 months, three stable adapted strains, designated as R, G, and Y, were developed with the sub-lethal concentration of phenol at 800, 1100, and 1400 mg/L, respectively, from 400 mg/L of V2 parent strain. All strains degraded phenol at their sub-lethal level within 24 h, their growth rate increased as the acclimation process continued and retained their degradation properties even after storing at -80 °C for more than 3 years. All adapted strains appeared coccoid with an ungranulated surface under electron microscope compared to typical rod-shaped parental strain V2 . The adapted Y strain also possessed superior degradation ability against aniline, benzoate, and toluene. This study demonstrated the use of long term acclimation process to develop efficient and better pollutant degrading bacterial strains with potentials in industrial and environmental bioremediation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

IRIS Toxicological Review of Naphthalene (1998 Final)

EPA Science Inventory

EPA announced the release of the final report, Toxicological Review of Naphthalene: in support of the Integrated Risk Information System (IRIS). The updated Summary for Naphthalene and accompanying toxicological review have been added to the IRIS Database.

Rhizoxin analogs, orfamide A and chitinase production contribute to the toxicity of Pseudomonas protegens strain Pf-5 to Drosophila melanogaster

USDA-ARS?s Scientific Manuscript database

Pseudomonas protegens strain Pf-5 is a soil bacterium that was first described for its activity in biological control of plant diseases and has since been shown to be lethal to certain insects. Among these is the fruit fly Drosophila melanogaster, a well-established model organism for studies evalu...

Phylogenetic and functional diversity of metagenomic libraries of phenol degrading sludge from petroleum refinery wastewater treatment system.

PubMed

Silva, Cynthia C; Hayden, Helen; Sawbridge, Tim; Mele, Pauline; Kruger, Ricardo H; Rodrigues, Marili Vn; Costa, Gustavo Gl; Vidal, Ramon O; Sousa, Maíra P; Torres, Ana Paula R; Santiago, Vânia Mj; Oliveira, Valéria M

2012-03-27

In petrochemical refinery wastewater treatment plants (WWTP), different concentrations of pollutant compounds are received daily in the influent stream, including significant amounts of phenolic compounds, creating propitious conditions for the development of particular microorganisms that can rapidly adapt to such environment. In the present work, the microbial sludge from a refinery WWTP was enriched for phenol, cloned into fosmid vectors and pyrosequenced. The fosmid libraries yielded 13,200 clones and a comprehensive bioinformatic analysis of the sequence data set revealed a complex and diverse bacterial community in the phenol degrading sludge. The phylogenetic analyses using MEGAN in combination with RDP classifier showed a massive predominance of Proteobacteria, represented mostly by the genera Diaphorobacter, Pseudomonas, Thauera and Comamonas. The functional classification of phenol degrading sludge sequence data set generated by MG-RAST showed the wide metabolic diversity of the microbial sludge, with a high percentage of genes involved in the aerobic and anaerobic degradation of phenol and derivatives. In addition, genes related to the metabolism of many other organic and xenobiotic compounds, such as toluene, biphenyl, naphthalene and benzoate, were found. Results gathered herein demonstrated that the phenol degrading sludge has complex phylogenetic and functional diversities, showing the potential of such community to degrade several pollutant compounds. This microbiota is likely to represent a rich resource of versatile and unknown enzymes which may be exploited for biotechnological processes such as bioremediation.

Analysis of the gene cluster encoding toluene/o-xylene monooxygenase from Pseudomonas stutzeri OX1

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

Bertoni, G.; Martino, M.; Galli, E.

The toluene/o-xylene monooxygenase cloned from Pseudomonas stutzeri OX1 displays a very broad range of substrates and a very peculiar regioselectivity, because it is able to hydroxylate more than one position on the aromatic ring of several hydrocarbons and phenols. The nucleotide sequence of the gene cluster coding for this enzymatic system has been determined. The sequence analysis revealed the presence of six open reading frames (ORFs) homologous to other genes clustered in operons coding for multicomponent monooxygenases found in benzene- and toluene-degradative pathways cloned from Pseudomonas strains. Significant similarities were also found with multicomponent monooxygenase systems for phenol, methane, alkene,more » and dimethyl sulfide cloned from different bacterial strains. The knockout of each ORF and complementation with the wild-type allele indicated that all six ORFs are essential for the full activity of the toluene/o-xylene monooxygenase in Escherichia coli. This analysis also shows that despite its activity on both hydrocarbons and phenols, toluene/o-xylene monooxygenase belongs to a toluene multicomponent monooxygenase subfamily rather than to the monooxygenases active on phenols.« less

Functional amyloid in Pseudomonas.

PubMed

Dueholm, Morten S; Petersen, Steen V; Sønderkær, Mads; Larsen, Poul; Christiansen, Gunna; Hein, Kim L; Enghild, Jan J; Nielsen, Jeppe L; Nielsen, Kåre L; Nielsen, Per H; Otzen, Daniel E

2010-08-01

Amyloids are highly abundant in many microbial biofilms and may play an important role in their architecture. Nevertheless, little is known of the amyloid proteins. We report the discovery of a novel functional amyloid expressed by a Pseudomonas strain of the P. fluorescens group. The amyloid protein was purified and the amyloid-like structure verified. Partial sequencing by MS/MS combined with full genomic sequencing of the Pseudomonas strain identified the gene coding for the major subunit of the amyloid fibril, termed fapC. FapC contains a thrice repeated motif that differs from those previously found in curli fimbrins and prion proteins. The lack of aromatic residues in the repeat shows that aromatic side chains are not needed for efficient amyloid formation. In contrast, glutamine and asparagine residues seem to play a major role in amyloid formation as these are highly conserved in curli, prion proteins and FapC. fapC is conserved in many Pseudomonas strains including the opportunistic pathogen P. aeruginosa and is situated in a conserved operon containing six genes, of which one encodes a fapC homologue. Heterologous expression of the fapA-F operon in Escherichia coli BL21(DE3) resulted in a highly aggregative phenotype, showing that the operon is involved in biofilm formation. © 2010 Blackwell Publishing Ltd.

Complete Genome Sequence of the Diesel-Degrading Acinetobacter sp. Strain DR1 ▿

PubMed Central

Jung, Jaejoon; Baek, Jeong-Hun; Park, Woojun

2010-01-01

The genus Acinetobacter is ubiquitous in soil, aquatic, and sediment environments and includes pathogenic strains, such as A. baumannii. Many Acinetobacter species isolated from various environments have biotechnological potential since they are capable of degrading a variety of pollutants. Acinetobacter sp. strain DR1 has been identified as a diesel degrader. Here we report the complete genome sequence of Acinetobacter sp. DR1 isolated from the soil of a rice paddy. PMID:20639327

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

Cultivar-Dependent Transcript Accumulation in Wheat Roots Colonized by Pseudomonas fluorescens Q8r1-96 Wild Type and Mutant Strains

USDA-ARS?s Scientific Manuscript database

In Triticum aestivum L. (wheat), the root-colonizing bacterium Pseudomonas fluorescens strain Q8r1-96 produces the antifungal metabolite 2,4-diacetylphloroglucinol (DAPG), suppresses damage caused by soilborne root pathogens, and modulates multiple stress or defense pathways in wheat roots. To test...

Tannic acid degradation by Klebsiella strains isolated from goat feces

PubMed Central

Tahmourespour, Arezoo; Tabatabaee, Nooroldin; Khalkhali, Hossein; Amini, Imane

2016-01-01

Background and Objectives: Tannins are toxic polyphenols that either bind and precipitate or condense proteins. The high tannin content of some plants is the preliminary limitation of using them as a ruminant feed. So, the aim of this study was the isolation and characterization of tannic acid degrading bacterial strains from goat feces before and after feeding on Pistachio-Soft Hulls as tannin rich diet (TRD). Materials and Methods: Bacterial strains capable of utilizing tannic acid as sole carbon and energy source were isolated and characterized from goat feces before and after feeding on TRD. Tannase activity, maximum tolerable concentration and biodegradation potential were assessed. Results: Four tannase positive isolates were identified as Klebsiella pneumoniae. Isolated strains showed the maximum tolerable concentration of 64g/L of tannin. The tannic acid degradation percentage at a concentration of 15.0 g/L reached a maximum of 68% after 24 h incubation, and more than 98% after 72 h incubation. The pH of the medium also decreased along with tannic acid utilization. Conclusions: It is obvious that TRD induced adaptive responses. Thus, while the bacteria were able to degrade and detoxify the tannic acids, they had to adapt in the presence of high concentrations of tannic acid. So, these isolates have an amazing potential for application in bioremediation, waste water treatment, also reduction of tannins antinutritional effects in animal feeds. PMID:27092220

Whole-Genome Sequence of Pseudomonas graminis Strain UASWS1507, a Potential Biological Control Agent and Biofertilizer Isolated in Switzerland.

PubMed

Crovadore, Julien; Calmin, Gautier; Chablais, Romain; Cochard, Bastien; Schulz, Torsten; Lefort, François

2016-10-06

We report here the whole-genome shotgun sequence of the strain UASWS1507 of the species Pseudomonas graminis, isolated in Switzerland from an apple tree. This is the first genome registered for this species, which is considered as a potential and valuable resource of biological control agents and biofertilizers for agriculture. Copyright © 2016 Crovadore et al.

Draft Genome Sequence of Aldehyde-Degrading Strain Halomonas axialensis ACH-L-8

PubMed Central

Ye, Jun; Ren, Chong; Shan, Xiexie

2016-01-01

Halomonas axialensis ACH-L-8, a deep-sea strain isolated from the South China Sea, has the ability to degrade aldehydes. Here, we present an annotated draft genome sequence of this species, which could provide fundamental molecular information on the aldehydes-degrading mechanism. PMID:27081145

Efficient biodegradation of acephate by Pseudomonas pseudoalcaligenes PS-5 in the presence and absence of heavy metal ions [Cu(II) and Fe(III)], and humic acid.

PubMed

Singh, Simranjeet; Kumar, Vijay; Upadhyay, Niraj; Singh, Joginder; Singla, Sourav; Datta, Shivika

2017-08-01

The present study was intended to investigate the biodegradation of acephate in aqueous media in the presence and in the absence of metal ions [Fe(III) and Cu(II)], and humic acid (HA). Biodegradations were performed using Pseudomonas pseudoalcaligenes PS-5 (PS-5) isolated from the heavy metal polluted site. Biodegradations were monitored by UV-Visible, FTIR, and electron spray ionization-mass spectrometry (ESI-MS) analyses. ESI-MS analysis revealed that PS-5 degraded acephate to two metabolites showing intense ions at mass-to-charge ratios ( m / z ) 62 and 97. The observed kinetic was the pseudo-first order, and half-life periods ( t 1/2 ) were 2.79 d -1 (of PS-5 + acephate), 3.45 d -1 [of PS-5 + acephate + Fe(III)], 3.16 d -1 [of PS-5 + acephate + Cu(II)], and 5.54 d -1 (of PS-5 + acephate + HA). A significant decrease in degradation rate of acephate was noticed in the presence of HA, and the same was confirmed by UV-Visible and TGA analyses. Strong aggregation behavior of acephate with humic acid in aqueous media was the major cause behind the slow degradation rate of acephate . New results on acephate metabolism by strain PS-5 in the presence and in the absence of metal ions [Fe(III) and Cu(II)] and humic acid were obtained. Results confirmed that Pseudomonas pseudoalcaligenes strain PS-5 was capable of mineralization of the acephate without formation of toxic metabolite methamidophos. More significantly, the Pseudomonas pseudoalcaligenes strain PS-5 could be useful as potential biological agents in effective bioremediation campaign for multi-polluted environments.

Draft Genome Sequence of Pseudomonas putida CA-3, a Bacterium Capable of Styrene Degradation and Medium-Chain-Length Polyhydroxyalkanoate Synthesis

PubMed Central

Almeida, Eduardo L.; Margassery, Lekha M.; O’Leary, Niall

2018-01-01

ABSTRACT Pseudomonas putida strain CA-3 is an industrial bioreactor isolate capable of synthesizing biodegradable polyhydroxyalkanoate polymers via the metabolism of styrene and other unrelated carbon sources. The pathways involved are subject to regulation by global cellular processes. The draft genome sequence is 6,177,154 bp long and contains 5,608 predicted coding sequences. PMID:29371359

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

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.

Mechanistic Insights into Elastin Degradation by Pseudolysin, the Major Virulence Factor of the Opportunistic Pathogen Pseudomonas aeruginosa

PubMed Central

Yang, Jie; Zhao, Hui-Lin; Ran, Li-Yuan; Li, Chun-Yang; Zhang, Xi-Ying; Su, Hai-Nan; Shi, Mei; Zhou, Bai-Cheng; Chen, Xiu-Lan; Zhang, Yu-Zhong

2015-01-01

Pseudolysin is the most abundant protease secreted by Pseudomonas aeruginosa and is the major extracellular virulence factor of this opportunistic human pathogen. Pseudolysin destroys human tissues by solubilizing elastin. However, the mechanisms by which pseudolysin binds to and degrades elastin remain elusive. In this study, we investigated the mechanism of action of pseudolysin on elastin binding and degradation by biochemical assay, microscopy and site-directed mutagenesis. Pseudolysin bound to bovine elastin fibers and preferred to attack peptide bonds with hydrophobic residues at the P1 and P1’ positions in the hydrophobic domains of elastin. The time-course degradation processes of both bovine elastin fibers and cross-linked human tropoelastin by pseudolysin were further investigated by microscopy. Altogether, the results indicate that elastin degradation by pseudolysin began with the hydrophobic domains on the fiber surface, followed by the progressive disassembly of macroscopic elastin fibers into primary structural elements. Moreover, our site-directed mutational results indicate that five hydrophobic residues in the S1-S1’ sub-sites played key roles in the binding of pseudolysin to elastin. This study sheds lights on the pathogenesis of P. aeruginosa infection. PMID:25905792

Metabolism of Tryptophans by Pseudomonas aureofaciens

PubMed Central

Elander, Richard P.; Mabe, James A.; Hamill, Robert H.; Gorman, Marvin

1968-01-01

Twenty-nine strains of Pseudomonas, classified as P. fluorescens biotype D or E or as P. multivorans, were examined for the production of pyrrolnitrin, an antifungal agent synthesized in P. aureofaciens. Eight strains were shown to produce pyrrolnitrin in shake-flask fermentation. Four cultures were from the multivorans taxon, and the remaining four were members of the fluorescens group. The antifungal agent produced in these strains was isolated and shown to be pyrrolnitrin by comparison with an authentic sample. The strains differed markedly with respect to the amount of pyrrolnitrin produced and in their utilization of exogenous tryptophan. Secondary metabolites, not related to pyrrolnitrin, were also examined and compared with those synthesized in P. aureofaciens. Marked differences were noted in both phenazine pigments and phenolic metabolites. The results of the study suggest that the production of pyrrolnitrin may be widespread in selected taxonomic groups of Pseudomonas. Images Fig. 1 PMID:4968963

Biofilm lifestyle enhances diesel bioremediation and biosurfactant production in the Antarctic polyhydroxyalkanoate producer Pseudomonas extremaustralis.

PubMed

Tribelli, Paula M; Di Martino, Carla; López, Nancy I; Raiger Iustman, Laura J

2012-09-01

Diesel is a widely distributed pollutant. Bioremediation of this kind of compounds requires the use of microorganisms able to survive and adapt to contaminated environments. Pseudomonas extremaustralis is an Antarctic bacterium with a remarkable survival capability associated to polyhydroxyalkanoates (PHAs) production. This strain was used to investigate the effect of cell growth conditions--in biofilm versus shaken flask cultures--as well as the inocula characteristics associated with PHAs accumulation, on diesel degradation. Biofilms showed increased cell growth, biosurfactant production and diesel degradation compared with that obtained in shaken flask cultures. PHA accumulation decreased biofilm cell attachment and enhanced biosurfactant production. Degradation of long-chain and branched alkanes was observed in biofilms, while in shaken flasks only medium-chain length alkanes were degraded. This work shows that the PHA accumulating bacterium P. extremaustralis can be a good candidate to be used as hydrocarbon bioremediation agent, especially in extreme environments.

Carbon Source-Dependent Inducible Metabolism of Veratryl Alcohol and Ferulic Acid in Pseudomonas putida CSV86

PubMed Central

Mohan, Karishma

2017-01-01

ABSTRACT Pseudomonas putida CSV86 degrades lignin-derived metabolic intermediates, viz., veratryl alcohol, ferulic acid, vanillin, and vanillic acid, as the sole sources of carbon and energy. Strain CSV86 also degraded lignin sulfonate. Cell respiration, enzyme activity, biotransformation, and high-pressure liquid chromatography (HPLC) analyses suggest that veratryl alcohol and ferulic acid are metabolized to vanillic acid by two distinct carbon source-dependent inducible pathways. Vanillic acid was further metabolized to protocatechuic acid and entered the central carbon pathway via the β-ketoadipate route after ortho ring cleavage. Genes encoding putative enzymes involved in the degradation were found to be present at fer, ver, and van loci. The transcriptional analysis suggests a carbon source-dependent cotranscription of these loci, substantiating the metabolic studies. Biochemical and quantitative real-time (qRT)-PCR studies revealed the presence of two distinct O-demethylases, viz., VerAB and VanAB, involved in the oxidative demethylation of veratric acid and vanillic acid, respectively. This report describes the various steps involved in metabolizing lignin-derived aromatic compounds at the biochemical level and identifies the genes involved in degrading veratric acid and the arrangement of phenylpropanoid metabolic genes as three distinct inducible transcription units/operons. This study provides insight into the bacterial degradation of lignin-derived aromatics and the potential of P. putida CSV86 as a suitable candidate for producing valuable products. IMPORTANCE Pseudomonas putida CSV86 metabolizes lignin and its metabolic intermediates as a carbon source. Strain CSV86 displays a unique property of preferential utilization of aromatics, including for phenylpropanoids over glucose. This report unravels veratryl alcohol metabolism and genes encoding veratric acid O-demethylase, hitherto unknown in pseudomonads, thereby providing new insight into the

Identification of a p-cresol degradation pathway by a GFP-based transposon in Pseudomonas and its dominant expression in colonies.

PubMed

Cho, Ah Ra; Lim, Eun Jin; Veeranagouda, Yaligara; Lee, Kyoung

2011-11-01

In this study, the chromosome-encoded pcuRCAXB genes that are required for p-cresol degradation have been identified by using a newly constructed green fluorescent protein (GFP)-based promoter probe transposon in the long-chain alkylphenol degrader Pseudomonas alkylphenolia. The deduced amino acid sequences of the genes showed the highest identities at the levels of 65-93% compared with those in the databases. The transposon was identified to be inserted in the pcuA gene, with the promoterless gfp gene being under the control of the pcu catabolic gene promoter. The expression of GFP was positively induced by p-cresol and was about 10 times higher by cells grown on agar than those in liquid culture. In addition, phydroxybenzoic acid was detected during p-cresol degradation. These results indicate that P. alkylphenolia additionally possesses a protocatechuate ortho-cleavage route for pcresol degradation that is dominantly expressed in colonies.

Comparative genomic, proteomic and exoproteomic analyses of three Pseudomonas strains reveals novel insights into the phosphorus scavenging capabilities of soil bacteria

PubMed Central

Murphy, Andrew R. J.; Scanlan, David J.; Bending, Gary D.; Jones, Alexandra M. E.; Moore, Jonathan D.; Goodall, Andrew; Hammond, John P.; Wellington, Elizabeth M. H.

2016-01-01

Summary Bacteria that inhabit the rhizosphere of agricultural crops can have a beneficial effect on crop growth. One such mechanism is the microbial‐driven solubilization and remineralization of complex forms of phosphorus (P). It is known that bacteria secrete various phosphatases in response to low P conditions. However, our understanding of their global proteomic response to P stress is limited. Here, exoproteomic analysis of Pseudomonas putida BIRD‐1 (BIRD‐1), Pseudomonas fluorescens SBW25 and Pseudomonas stutzeri DSM4166 was performed in unison with whole‐cell proteomic analysis of BIRD‐1 grown under phosphate (Pi) replete and Pi deplete conditions. Comparative exoproteomics revealed marked heterogeneity in the exoproteomes of each Pseudomonas strain in response to Pi depletion. In addition to well‐characterized members of the PHO regulon such as alkaline phosphatases, several proteins, previously not associated with the response to Pi depletion, were also identified. These included putative nucleases, phosphotriesterases, putative phosphonate transporters and outer membrane proteins. Moreover, in BIRD‐1, mutagenesis of the master regulator, phoBR, led us to confirm the addition of several novel PHO‐dependent proteins. Our data expands knowledge of the Pseudomonas PHO regulon, including species that are frequently used as bioinoculants, opening up the potential for more efficient and complete use of soil complexed P. PMID:27233093

Pseudomonas yangmingensis sp. nov., an alkaliphilic denitrifying species isolated from a hot spring.

PubMed

Wong, Biing-Teo; Lee, Duu-Jong

2014-01-01

This study isolated and identified a facultative, alkaliphilic, denitrifying Pseudomonas strain designed as CRS1 from a hot spring, Yang-Ming Mountain, Taiwan. The biochemical characterization, phenotypic characteristics and phylogenetic relationship of strain CRS1 were studied. On the basis of the 16S rRNA sequence similarity, phenotypic and genotypic characteristics and chemotaxonomic data, the strain CRS1 represents a novel species of the genus Pseudomonas, for which the name Pseudomonas yangmingensis sp. nov., is proposed. The strain CRS1 is a facultative autotrophic bacterium that has capability of mixotrophic and heterotrophic denitrification. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Draft Genome Sequence of the 2-Chloro-4-Nitrophenol-Degrading Bacterium Arthrobacter sp. Strain SJCon

PubMed Central

Vikram, Surendra; Kumar, Shailesh; Vaidya, Bhumika; Pinnaka, Anil Kumar

2013-01-01

We report the 4.39-Mb draft genome sequence of the 2-chloro-4-nitrophenol-degrading bacterium Arthrobacter sp. strain SJCon, isolated from a pesticide-contaminated site. The draft genome sequence of strain SJCon will be helpful in studying the genetic pathways involved in the degradation of several aromatic compounds. PMID:23516196

[Predominant strains of polycyclic aromatic hydrocarbon-degrading consortia from deep sea of the Middle Atlantic Ridge].

PubMed

Cui, Zhisong; Shao, Zongze

2009-07-01

In order to identify the predominant strains of polycyclic aromatic hydrocarbon (PAH)-degrading consortia harboring in sea water and surface sediment collected from deep sea of the Middle Atlantic Ridge. We employed enrichment method and spread-plate method to isolate cultivable bacteria and PAHs degraders from deep sea samples. Phylogenetic analysis was conducted by 16S rRNA gene sequencing of the bacteria. Then we analyzed the dominant bacteria in the PAHs-degrading consortia by denaturing gradient gel electrophoresis (DGGE) combined with DNA sequencing. Altogether 16 cultivable bacteria were obtained, including one PAHs degrader Novosphingobium sp. 4D. Phylogenetic analysis showed that strains closely related to Alcanivorax dieselolei NO1A (5/16) and Tistrella mobilis TISTR 1108T (5/16) constituted two biggest groups among the cultivable bacteria. DGGE analysis showed that strain 4L (also 4M and 4N, Alcanivorax dieselolei NO1A, 99.21%), 4D (Novosphingobium pentaromativorans US6-1(T), 97.07%) and 4B (also 4E, 4H and 4K, Tistrella mobilis TISTR 1108T, > 99%) dominated the consortium MC2D. While in consortium MC3CO, the predominant strains were strain 5C (also 5H, Alcanivorax dieselolei NO1A, > 99%), uncultivable strain represented by band 5-8 (Novosphingobium aromaticivorans DSM 12444T, 99.41%), 5J (Tistrella mobilis TISTR 1108T, 99.52%) and 5F (also 5G, Thalassospira lucentensis DSM 14000T, < 97%). We found that strains of genus Alcanivorax, Novosphingobium, Tistrella and Thalassospira were predominant bacteria of PAHs-degrading consortia in sea water and surface sediment of Middle Atlantic Ridge deep sea, with Novosphingobium spp. as their main PAHs degraders.

Interaction between the Bacterium Pseudomonas fluorescens strain CHA0, its genetic derivatives and vermiculite: Effects on chemical, mineralogical and mechanical properties of vermiculite

NASA Astrophysics Data System (ADS)

Mueller, Barbara

2016-04-01

Using bacteria of the strain Pseudomonas fluorescens wild type CHA0 and its genetic derivative strains CHA77, CHA89, CHA400, CHA631 and CHA661 (which differ in one gene only) the changes in chemical, mineralogical and rheological properties of the clay mineral vermiculite affected by microbial activity were studied in order to test whether the individually different production of metabolites by the genetically engineered strains may alter the clay mineral vermiculite in distinct ways. With the novel strategy of working with living wild type bacteria, their genetic derivatives and clay, the following properties of the mineral altered by the various strains of Pseudomonas fluorescens were determined: grain size, X-Ray diffraction pattern, intercrystalline swelling with glycerol, layer charge, CEC, BET surface and uptake of trace elements. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to determine the changes in major, minor and trace elements of the clay vermiculite affected by microbial activity. Among all analyzed trace elements, Fe, Mn and Cu are the most interesting. Fe and Mn are taken up from the clay mineral by all bacterial strains whereas Cu is only removed from vermiculite by strains CHA0, CHA77, CHA400 and CHA661. The latter mentioned strains all produce the antibiotics 2,4-diacetylphloroglucinol and monoacetylphloroglucinol which can complex Cu efficiently. Therefore the alteration of only one gene of the bacteria is causing significant effects on the clay mineral.

Early Arabidopsis root hair growth stimulation by pathogenic strains of Pseudomonas syringae.

PubMed

Pecenková, Tamara; Janda, Martin; Ortmannová, Jitka; Hajná, Vladimíra; Stehlíková, Zuzana; Žárský, Viktor

2017-09-01

Selected beneficial Pseudomonas spp. strains have the ability to influence root architecture in Arabidopsis thaliana by inhibiting primary root elongation and promoting lateral root and root hair formation. A crucial role for auxin in this long-term (1week), long-distance plant-microbe interaction has been demonstrated. Arabidopsis seedlings were cultivated in vitro on vertical plates and inoculated with pathogenic strains Pseudomonas syringae pv. maculicola (Psm) and P. syringae pv. tomato DC3000 (Pst), as well as Agrobacterium tumefaciens (Atu) and Escherichia coli (Eco). Root hair lengths were measured after 24 and 48h of direct exposure to each bacterial strain. Several Arabidopsis mutants with impaired responses to pathogens, impaired ethylene perception and defects in the exocyst vesicle tethering complex that is involved in secretion were also analysed. Arabidopsis seedling roots infected with Psm or Pst responded similarly to when infected with plant growth-promoting rhizobacteria; root hair growth was stimulated and primary root growth was inhibited. Other plant- and soil-adapted bacteria induced similar root hair responses. The most compromised root hair growth stimulation response was found for the knockout mutants exo70A1 and ein2. The single immune pathways dependent on salicylic acid, jasmonic acid and PAD4 are not directly involved in root hair growth stimulation; however, in the mutual cross-talk with ethylene, they indirectly modify the extent of the stimulation of root hair growth. The Flg22 peptide does not initiate root hair stimulation as intact bacteria do, but pretreatment with Flg22 prior to Psm inoculation abolished root hair growth stimulation in an FLS2 receptor kinase-dependent manner. These early response phenomena are not associated with changes in auxin levels, as monitored with the pDR5::GUS auxin reporter. Early stimulation of root hair growth is an effect of an unidentified component of living plant pathogenic bacteria. The root

High-Throughput Screening for a Moderately Halophilic Phenol-Degrading Strain and Its Salt Tolerance Response

PubMed Central

Lu, Zhi-Yan; Guo, Xiao-Jue; Li, Hui; Huang, Zhong-Zi; Lin, Kuang-Fei; Liu, Yong-Di

2015-01-01

A high-throughput screening system for moderately halophilic phenol-degrading bacteria from various habitats was developed to replace the conventional strain screening owing to its high efficiency. Bacterial enrichments were cultivated in 48 deep well microplates instead of shake flasks or tubes. Measurement of phenol concentrations was performed in 96-well microplates instead of using the conventional spectrophotometric method or high-performance liquid chromatography (HPLC). The high-throughput screening system was used to cultivate forty-three bacterial enrichments and gained a halophilic bacterial community E3 with the best phenol-degrading capability. Halomonas sp. strain 4-5 was isolated from the E3 community. Strain 4-5 was able to degrade more than 94% of the phenol (500 mg·L−1 starting concentration) over a range of 3%–10% NaCl. Additionally, the strain accumulated the compatible solute, ectoine, with increasing salt concentrations. PCR detection of the functional genes suggested that the largest subunit of multicomponent phenol hydroxylase (LmPH) and catechol 1,2-dioxygenase (C12O) were active in the phenol degradation process. PMID:26020478

A diagnostic PCR assay for the detection of an Australian epidemic strain of Pseudomonas aeruginosa

PubMed Central

2010-01-01

Background Chronic lung infection with the bacterium Pseudomonas aeruginosa is one of the hallmarks of cystic fibrosis (CF) and is associated with worsening lung function, increased hospitalisation and reduced life expectancy. A virulent clonal strain of P. aeruginosa (Australian epidemic strain I; AES-I) has been found to be widespread in CF patients in eastern Australia. Methods Suppression subtractive hybridization (SSH) was employed to identify genetic sequences that are present in the AES-I strain but absent from the sequenced reference strain PAO1. We used PCR to evaluate the distribution of several of the AES-I loci amongst a collection of 188 P. aeruginosa isolates which was comprised of 35 AES-I isolates (as determined by PFGE), 78 non-AES-I CF isolates including other epidemic CF strains as well as 69 P. aeruginosa isolates from other clinical and environmental sources. Results We have identified a unique AES-I genetic locus that is present in all 35 AES-I isolates tested and not present in any of the other 153 P. aeruginosa strains examined. We have used this unique AES-I locus to develop a diagnostic PCR and a real-time PCR assay to detect the presence of P. aeruginosa and AES-I in patient sputum samples. Conclusions We have developed diagnostic PCR assays that are 100% sensitive and 100% specific for the P. aeruginosa strain AES-I. We have also shown that Whatman FTA® Elute cards may be used with PCR-based assays to rapidly detect the presence of P. aeruginosa strains in CF sputum. PMID:20637114

Draft Genome Sequence of Pseudomonas putida CA-3, a Bacterium Capable of Styrene Degradation and Medium-Chain-Length Polyhydroxyalkanoate Synthesis.

PubMed

Almeida, Eduardo L; Margassery, Lekha M; O'Leary, Niall; Dobson, Alan D W

2018-01-25

Pseudomonas putida strain CA-3 is an industrial bioreactor isolate capable of synthesizing biodegradable polyhydroxyalkanoate polymers via the metabolism of styrene and other unrelated carbon sources. The pathways involved are subject to regulation by global cellular processes. The draft genome sequence is 6,177,154 bp long and contains 5,608 predicted coding sequences. Copyright © 2018 Almeida et al.

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

Transferable Drug Resistance in Pseudomonas aeruginosa1

PubMed Central

Bryan, L. E.; Elzen, H. M. Van Den; Tseng, Jui Teng

1972-01-01

Three strains of Pseudomonas aeruginosa were demonstrated to transfer double-drug resistance by conjugation to a P. aeruginosa recipient at frequencies of 10−4 to 10−2 per recipient cell. Two of the three strains also transferred to Escherichia coli at frequencies which were 103- to 105-fold lower, but the third strain could not be demonstrated to do so. The latter strain, however, conferred maleness on the Pseudomonas recipient. The transfer of streptomycin resistance was associated with the acquisition of streptomycin phosphorylase by both P. aeruginosa and E. coli recipients. Maximal broth mating frequencies were obtained with nonagitated cultures less than 1 mm in depth. A pyocine selection system based on donor sensitivity and recipient resistance is described and appears to have future value as a generalized selective device for use after matings. PMID:4207756

Pseudomonas Genome Database: facilitating user-friendly, comprehensive comparisons of microbial genomes.

PubMed

Winsor, Geoffrey L; Van Rossum, Thea; Lo, Raymond; Khaira, Bhavjinder; Whiteside, Matthew D; Hancock, Robert E W; Brinkman, Fiona S L

2009-01-01

Pseudomonas aeruginosa is a well-studied opportunistic pathogen that is particularly known for its intrinsic antimicrobial resistance, diverse metabolic capacity, and its ability to cause life threatening infections in cystic fibrosis patients. The Pseudomonas Genome Database (http://www.pseudomonas.com) was originally developed as a resource for peer-reviewed, continually updated annotation for the Pseudomonas aeruginosa PAO1 reference strain genome. In order to facilitate cross-strain and cross-species genome comparisons with other Pseudomonas species of importance, we have now expanded the database capabilities to include all Pseudomonas species, and have developed or incorporated methods to facilitate high quality comparative genomics. The database contains robust assessment of orthologs, a novel ortholog clustering method, and incorporates five views of the data at the sequence and annotation levels (Gbrowse, Mauve and custom views) to facilitate genome comparisons. A choice of simple and more flexible user-friendly Boolean search features allows researchers to search and compare annotations or sequences within or between genomes. Other features include more accurate protein subcellular localization predictions and a user-friendly, Boolean searchable log file of updates for the reference strain PAO1. This database aims to continue to provide a high quality, annotated genome resource for the research community and is available under an open source license.

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

PubMed