Whole genome sequence analysis of an Alachlor and Endosulfan degrading Pseudomonas strain W15Feb9B isolated from Ochlockonee River, Florida

Directory of Open Access Journals (Sweden)

Ashvini Chauhan

2016-06-01

Full Text Available We recently isolated a Pseudomonas sp. strain W15Feb9B from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides - Alachlor [(2-chloro-2′,6′-diethylphenyl-N (methoxymethylacetanilide] and Endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(edi-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain W15Feb9B, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of strain 2385 has been deposited in GenBank under accession number JTKF00000000; BioSample number SAMN03151543. The sequences obtained from strain 2385 assembled into 192 contigs with a genome size of 6,031,588, G + C content of 60.34, and 5512 total number of putative genes. RAST annotated a total of 542 subsystems in the genome of strain W15Feb9B along with the presence of 5360 coding sequences. A genome wide survey of strain W15Feb9B indicated that it has the potential to degrade several other pollutants including atrazine, caprolactam, dioxin, PAHs (such as naphthalene and several chloroaromatic compounds.

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

Directory of Open Access Journals (Sweden)

Merike Jõesaar

Full Text Available 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.

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

Directory of Open Access Journals (Sweden)

Jingjing Yang

2018-05-01

Full Text Available 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 (Ki of 482.1673 mg⋅L-1 and maximum specific degradation constant (qmax 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.

Anaerobic degradation of naphthalene by the mixed bacteria under nitrate reducing conditions

International Nuclear Information System (INIS)

Dou Junfeng; Liu Xiang; Ding Aizhong

2009-01-01

Mixed bacteria were enriched from soil samples contaminated with polycyclic aromatic hydrocarbons (PAHs). The anaerobic degradation characteristics by the enriched bacteria with different initial naphthalene concentrations were investigated under nitrate reducing conditions. The results showed that the mixed bacteria could degrade nearly all the naphthalene over the incubations of 25 days when the initial naphthalene concentration was below 30 mg/L. The degradation rates of naphthalene increased with increasing initial concentrations. A high naphthalene concentration of 30 mg/L did not inhibit neither on the bacterial growth nor on the naphthalene degradation ability. The accumulation of nitrite was occurred during the reduction of nitrate, and a nitrite concentration of 50 mg/L had no inhibition effect on the degradation of naphthalene. The calculation of electron balances revealed that most of the naphthalene was oxidized whereas a small proportion was used for cell synthesis.

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

Science.gov (United States)

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.

Characterization of cefalexin degradation capabilities of two Pseudomonas strains isolated from activated sludge.

Science.gov (United States)

Lin, Bokun; Lyu, Jinling; Lyu, Xian-jin; Yu, Han-qing; Hu, Zhong; Lam, James C W; Lam, Paul K S

2015-01-23

Pharmaceuticals have recently been regarded as contaminants of emerging concern. To date, there is limited knowledge about antibiotic-degrading microorganisms in conventional activated sludge treatment systems and their characteristics toward antibiotic degradation especially in the presence of a pharmaceutical mixture. As such, antibiotic-degrading microorganisms were investigated and isolated from the activated sludge, and their degradation capabilities were evaluated. Two strains of cefalexin-degrading bacteria CE21 and CE22 were isolated and identified as Pseudomonas sp. in the collected activated sludge. Strain CE22 was able to degrade over 90% of cefalexin, while CE21 was able to remove 46.7% of cefalexin after incubation for 24h. The removal efficiency of cefalexin by CE22, different from that of CE21, was not significantly affected by an increase in cefalexin concentration, even up to 10ppm, however the presence of 1ppm of other pharmaceuticals had a significant effect on the degradation of cefalexin by CE22, but no significant effect on CE21. The degradation product of cefalexin by the two strains was identified to be 2-hydroxy-3-phenyl pyrazine. Our results also indicated that CE21 and CE22 were able to degrade caffeine, salicylic acid and chloramphenicol. Moreover, CE21 was found to be capable of eliminating sulfamethoxazole and naproxen. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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).

Hydrocarbon-degradation by Isolate Pseudomonas lundensis UTAR FPE2

Directory of Open Access Journals (Sweden)

Adeline, S. Y. Ting

2009-01-01

Full Text Available In this study, the potential of isolate Pseudomonas lundensis UTAR FPE2 as a hydrocarbon degrader was established. Their biodegradation activity was first detected with the formation of clearing zones on Bushnell-Hass agar plates, with the largest diameter observed on plates supplemented with paraffin, followed by mineral oil and petrol. Utilization of hydrocarbon sources were again detected in broth cultures supplemented with similar hydrocarbon substrates, where the mean viable cell count recovered from hydrocarbon-supplemented broth cultures were higher than the initial inoculum except for napthalene. In both tests, the isolate showed higher degradability towards aliphatic hydrocarbon sources, and the least activity towards the aromatic hydrocarbon naphthalene. The isolate P. lundensis UTAR FPE2 (8 log10 cfu/mL also degraded crude diesel sample, with 69% degradation during the first three days. To conclude, this study suggests the potential use of this isolate for bioremediation of hydrocarbon-contaminated environments.

Genome Sequence of Pseudomonas sp. Strain Chol1, a Model Organism for the Degradation of Bile Salts and Other Steroid Compounds

KAUST Repository

Holert, Johannes; Alam, Intikhab; Larsen, Michael; Antunes, Andre; Bajic, Vladimir B.; Stingl, Ulrich; Philipp, Bodo

2013-01-01

Bacterial degradation of steroid compounds is of high ecological and biotechnological relevance. Pseudomonas sp. strain Chol1 is a model organism for studying the degradation of the steroid compound cholate. Its draft genome sequence is presented and reveals one gene cluster responsible for the metabolism of steroid compounds.

Genome Sequence of Pseudomonas sp. Strain Chol1, a Model Organism for the Degradation of Bile Salts and Other Steroid Compounds

KAUST Repository

Holert, Johannes

2013-01-15

Bacterial degradation of steroid compounds is of high ecological and biotechnological relevance. Pseudomonas sp. strain Chol1 is a model organism for studying the degradation of the steroid compound cholate. Its draft genome sequence is presented and reveals one gene cluster responsible for the metabolism of steroid compounds.

Pseudomonas putida CSV86: a candidate genome for genetic bioaugmentation.

Directory of Open Access Journals (Sweden)

Vasundhara Paliwal

Full Text Available Pseudomonas putida CSV86, a plasmid-free strain possessing capability to transfer the naphthalene degradation property, has been explored for its metabolic diversity through genome sequencing. The analysis of draft genome sequence of CSV86 (6.4 Mb revealed the presence of genes involved in the degradation of naphthalene, salicylate, benzoate, benzylalcohol, p-hydroxybenzoate, phenylacetate and p-hydroxyphenylacetate on the chromosome thus ensuring the stability of the catabolic potential. Moreover, genes involved in the metabolism of phenylpropanoid and homogentisate, as well as heavy metal resistance, were additionally identified. Ability to grow on vanillin, veratraldehyde and ferulic acid, detection of inducible homogentisate dioxygenase and growth on aromatic compounds in the presence of heavy metals like copper, cadmium, cobalt and arsenic confirm in silico observations reflecting the metabolic versatility. In silico analysis revealed the arrangement of genes in the order: tRNA(Gly, integrase followed by nah operon, supporting earlier hypothesis of existence of a genomic island (GI for naphthalene degradation. Deciphering the genomic architecture of CSV86 for aromatic degradation pathways and identification of elements responsible for horizontal gene transfer (HGT suggests that genetic bioaugmentation strategies could be planned using CSV86 for effective bioremediation.

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

OpenAIRE

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 degrad...

Draft Genome Sequence of the Model Naphthalene-Utilizing Organism Pseudomonas putida OUS82

DEFF Research Database (Denmark)

Tay, Martin; Roizman, Dan; Cohen, Yehuda

2014-01-01

Pseudomonas putida OUS82 was isolated from petrol- and oil-contaminated soil in 1992, and ever since, it has been used as a model organism to study the microbial assimilation of naphthalene and phenanthrene. Here, we report the 6.7-Mb draft genome sequence of P. putida OUS82 and analyze its...

Physiological and biochemical characterization of a novel nicotine-degrading bacterium Pseudomonas geniculata N1.

Directory of Open Access Journals (Sweden)

Yanghui Liu

Full Text Available Management of solid wastes with high nicotine content, such as those accumulated during tobacco manufacturing, poses a major challenge, which can be addressed by using bacteria such as Pseudomonas and Arthrobacter. In this study, a new species of Pseudomonas geniculata, namely strain N1, which is capable of efficiently degrading nicotine, was isolated and identified. The optimal growth conditions for strain N1 are a temperature of 30°C, and a pH 6.5, at a rotation rate of 120 rpm min(-1 with 1 g l(-1 nicotine as the sole source of carbon and nitrogen. Myosmine, cotinine, 6-hydroxynicotine, 6-hydroxy-N-methylmyosmine, and 6-hydroxy-pseudooxynicotine were detected as the five intermediates through gas chromatography-mass and liquid chromatography-mass analyses. The identified metabolites were different from those generated by Pseudomonas putida strains. The analysis also highlighted the bacterial metabolic diversity in relation to nicotine degradation by different Pseudomonas strains.

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

Science.gov (United States)

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

Cyanide Degradation by Pseudomonas pseudoalcaligenes Strain W_2 Isolated from Mining Effluent

International Nuclear Information System (INIS)

Belinda Tiong; Zaratulnur Mohd Bahari; Nor Sahslin Irwan Shah Lee; Jafariah Jaafar; Zaharah Ibrahim; Shafinaz Shahir

2015-01-01

Cyanide is highly toxic to the living organisms as it inhibits respiration system in the cell mitochondria. Cyanide is commonly used in gold extraction process and its discharge into the environment not only causes pollution but it also brings harm to the surrounding population. Chemical treatment is expensive and the use of hazardous compound can exacerbate the problem. Biodegradation offers cheap and safe alternative as it overcomes the problems faced by chemical treatment. In this study, indigenous bacteria from mining wastewater were isolated. Cyanide degradation was done via shake flask method. A bacterium, designated W2 was found able to grow in the mining wastewater. 16S rRNA analysis identified the strain as Pseudomonas pseudoalcaligenes which could tolerate up to 39 mg/L cyanide concentration and growth was depleted at 52 mg/L. 60 % cyanide degradation was achieved in wastewater containing medium. End-product analysis from high performance liquid chromatography (HPLC) detected formamide implicating the role of cyanide hydratase in cyanide degradation. It can be concluded that P. pseudoalcaligenes is capable of biodegrading cyanide and its potential in wastewater treatment containing cyanide is feasible. (author)

Aflatoxin B1 Degradation by a Pseudomonas Strain

Directory of Open Access Journals (Sweden)

Lancine Sangare

2014-10-01

Full Text Available Aflatoxin B1 (AFB1, one of the most potent naturally occurring mutagens and carcinogens, causes significant threats to the food industry and animal production. In this study, 25 bacteria isolates were collected from grain kernels and soils displaying AFB1 reduction activity. Based on its degradation effectiveness, isolate N17-1 was selected for further characterization and identified as Pseudomonas aeruginosa. P. aeruginosa N17-1 could degrade AFB1, AFB2 and AFM1 by 82.8%, 46.8% and 31.9% after incubation in Nutrient Broth (NB medium at 37 °C for 72 h, respectively. The culture supernatant of isolate N17-1 degraded AFB1 effectively, whereas the viable cells and intra cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Maximum degradation was observed at 55 °C. Ions Mn2+ and Cu2+ were activators for AFB1 degradation, however, ions Mg2+, Li+, Zn2+, Se2+, Fe3+ were strong inhibitors. Treatments with proteinase K and proteinase K plus SDS significantly reduced the degradation activity of the culture supernatant. No degradation products were observed based on preliminary LC-QTOF/MS analysis, indicating AFB1 was metabolized to degradation products with chemical properties different from that of AFB1. The results indicated that the degradation of AFB1 by P. aeruginosa N17-1 was enzymatic and could have a great potential in industrial applications. This is the first report indicating that the isolate of P. aeruginosa possesses the ability to degrade aflatoxin.

Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain

Directory of Open Access Journals (Sweden)

Shanshan Li

2016-09-01

Full Text Available Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE, which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C5-C8, accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA. When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition.

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

Science.gov (United States)

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.

A newly isolated Pseudomonas putida S-1 strain for batch-mode-propanethiol degradation and continuous treatment of propanethiol-containing waste gas

Energy Technology Data Exchange (ETDEWEB)

Chen, Dong-Zhi, E-mail: cdz@zjut.edu.cn [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Sun, Yi-Ming; Han, Li-Mei [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Chen, Jing [College of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316004 (China); Ye, Jie-Xu; Chen, Jian-Meng [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)

2016-01-25

Highlights: • A novel strain capable of effectively degrading 1-propanethiol (PT) was isolated. • Cells could be feasibly cultured in nutrition-rich media for PT degradation. • A possible pathway for PT degradation was proposed. • Pseudomonas putida S-1 could degrade mixed pollutants with diauxic growth. • Continuous removal of gaseous PT with or without isopropanol was demonstrated. - Abstract: Pseudomonas putida S-1 was isolated from activated sludge. This novel strain was capable of degrading malodorous 1-propanethiol (PT). PT degradation commenced with no lag phase by cells pre-grown in nutrition-rich media, such as Luria–Bertani (LB), and PT-contained mineral medium at specific growth rates of 0.10–0.19 h{sup −1}; this phenomenon indicated the operability of a large-scale cell culture. A possible PT degradation pathway was proposed on the basis of the detected metabolites, including dipropyl disulfide, 3-hexanone, 2-hexanone, 3-hexanol, 2-hexanol, S{sup 0}, SO{sub 4}{sup 2−}, and CO{sub 2}. P. putida S-1 could degrade mixed pollutants containing PT, diethyl disulfide, isopropyl alcohol, and acetaldehyde, and LB-pre-cultured cells underwent diauxic growth. Waste gas contaminated with 200–400 mg/m{sup 3} PT was continuously treated by P. putida S-1 pre-cultured in LB medium in a completely stirred tank reactor. The removal efficiencies exceeded 88% when PT stream was mixed with 200 mg/m{sup 3} isopropanol; by contrast, the removal efficiencies decreased to 60% as the empty bed residence time was shortened from 40 s to 20 s.

A newly isolated Pseudomonas putida S-1 strain for batch-mode-propanethiol degradation and continuous treatment of propanethiol-containing waste gas

International Nuclear Information System (INIS)

Chen, Dong-Zhi; Sun, Yi-Ming; Han, Li-Mei; Chen, Jing; Ye, Jie-Xu; Chen, Jian-Meng

2016-01-01

Highlights: • A novel strain capable of effectively degrading 1-propanethiol (PT) was isolated. • Cells could be feasibly cultured in nutrition-rich media for PT degradation. • A possible pathway for PT degradation was proposed. • Pseudomonas putida S-1 could degrade mixed pollutants with diauxic growth. • Continuous removal of gaseous PT with or without isopropanol was demonstrated. - Abstract: Pseudomonas putida S-1 was isolated from activated sludge. This novel strain was capable of degrading malodorous 1-propanethiol (PT). PT degradation commenced with no lag phase by cells pre-grown in nutrition-rich media, such as Luria–Bertani (LB), and PT-contained mineral medium at specific growth rates of 0.10–0.19 h"−"1; this phenomenon indicated the operability of a large-scale cell culture. A possible PT degradation pathway was proposed on the basis of the detected metabolites, including dipropyl disulfide, 3-hexanone, 2-hexanone, 3-hexanol, 2-hexanol, S"0, SO_4"2"−, and CO_2. P. putida S-1 could degrade mixed pollutants containing PT, diethyl disulfide, isopropyl alcohol, and acetaldehyde, and LB-pre-cultured cells underwent diauxic growth. Waste gas contaminated with 200–400 mg/m"3 PT was continuously treated by P. putida S-1 pre-cultured in LB medium in a completely stirred tank reactor. The removal efficiencies exceeded 88% when PT stream was mixed with 200 mg/m"3 isopropanol; by contrast, the removal efficiencies decreased to 60% as the empty bed residence time was shortened from 40 s to 20 s.

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

Science.gov (United States)

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...

Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

Directory of Open Access Journals (Sweden)

Dnyanada S. Khanolkar

2014-12-01

Full Text Available 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.

Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

Science.gov (United States)

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

Anaerobic degradation of long-chain alkylamines by a denitrifying Pseudomonas stutzeri

NARCIS (Netherlands)

Nguyen, P.D.; Ginkel, van C.G.; Plugge, C.M.

2008-01-01

The anaerobic degradation of tetradecylamine and other long-chain alkylamines by a newly isolated denitrifying bacterium was studied. Strain ZN6 was isolated from a mixture of soil and active sludge and was identified as representing Pseudomonas stutzeri, based on partial 16S rRNA gene sequence

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

Directory of Open Access Journals (Sweden)

Santanu Pailan

2015-11-01

Full Text Available 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.

Naphthalene and pyrene degradation in contaminated soil as a ...

African Journals Online (AJOL)

The effect of soil particle size distribution and percent organic matter on the degradation rate of naphthalene and pyrene in a water medium of 7.05 ml/min at 27 ± 2oC in a soil reactor was studied. Analysis of the pattern of disappearance of these polycyclic aromatic hydrocarbons (PAHs) using various particle sizes showed ...

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

Science.gov (United States)

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.

Optimal decolorization and kinetic modeling of synthetic dyes by Pseudomonas strains.

Science.gov (United States)

Yu, J; Wang, X; Yue, P L

2001-10-01

Pseudomonas spp were isolated from an anaerobic-aerobic dyeing house wastewater treatment facility as the most active azo-dye degraders. Decolorization of azo dyes and non-azo dyes including anthraquinone, metal complex and indigo was compared with individual strains and a bacterial consortium consisting of the individual strain and municipal sludge (50 50wt). The consortium showed a significant improvement on decolorization of two recalcitrant non-azo dyes, but little effect on the dyes that the individual strains could degrade to a great or moderate extent. Decolorization of Acid violet 7 (monoazo) by a Pseudomonas strain GM3 was studied in detail under various conditions. The optimum decolorization activity was observed in a narrow pH range (7-8), a narrow temperature range (35-40 degrees C), and at the presence of organic and ammonium nitrogen. Nitrate had a severe inhibitory effect on azo dye decolorization: 10 mg/L led to 50% drop in decolorization activity and 1000 mg/L to complete activity depression. A kinetic model is established giving the dependence of decolorization rate on cell mass concentration (first-order) and dye concentration (half order). The rate increased with temperature from 10 to 35 C, which can be predicted by Arrhenius equation with the activation energy of 16.87 kcal/mol and the frequency factor of 1.49 x 10(11) (mg L)1/2/g DCM min.

Aerobic degradation of N-methyl-4-nitroaniline (MNA by Pseudomonas sp. strain FK357 isolated from soil.

Directory of Open Access Journals (Sweden)

Fazlurrahman Khan

Full Text Available 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.

In situ, real-time catabolic gene expression: Extraction and characterization of naphthalene dioxygenase mRNA transcripts from groundwater

International Nuclear Information System (INIS)

Wilson, M.S.; Bakermans, C.; Madsen, E.L.

1999-01-01

The authors developed procedures for isolating and characterizing in situ-transcribed mRNA from groundwater microorganisms catabolizing naphthalene at a coal tar waste-contaminated site. Groundwater was pumped through 0.22-microm-pore-size filters, which were then frozen to dry ice-ethanol. RNA was extracted from the frozen filters by boiling sodium dodecyl sulfate lysis and acidic phenol-chloroform extraction. Transcript characterization was performed with a series of PCR primers designed to amplify nahAc homologs. Several primer pairs were found to amplify nahAc homologs representing the entire diversity of the naphthalene-degrading genes. The environmental RNA extract was reverse transcribed, and the resultant mixture of cDNAs was amplified by PCR. A digoxigenin-labeled probe mixture was produced by PCR amplification of groundwater cDNA. This probe mixture hybridized under stringent conditions with the corresponding PCR products from naphthalene-degrading bacteria carrying a variety of nahAc homologs, indicating that diverse dioxygenase transcripts had been retrieved from groundwater. Diluted and undiluted cDNA preparations were independently amplified, and 28 of the resulting PCR products were cloned and sequenced. Sequence comparisons revealed two major groups related to the dioxygenase genes ndoB and dntAc, previously cloned from Pseudomonas putida NCIB 9816-4 and Burkholderia sp. strain DNT, respectively. A distinctive subgroup of sequences was found only in experiments performed with the undiluted cDNA preparation. To the authors' knowledge, these results are the first to directly document in situ transcription of genes encoding naphthalene catabolism at a contaminated site by indigenous microorganisms. The retrieved sequences represent greater diversity than has been detected at the study site by culture-based approaches

Biodegradation of Chlorpyrifos by Pseudomonas Resinovarans Strain AST2.2 Isolated from Enriched Cultures.

OpenAIRE

Anish Sharma*,; Jyotsana Pandit; Ruchika Sharma and; Poonam Shirkot

2016-01-01

A bacterial strain AST2.2 with chlorpyrifos degrading ability was isolated by enrichment technique from apple orchard soil with previous history of chlorpyrifos use. Based on the morphological, biochemical tests and 16S rRNA sequence analysis, AST2.2 strain was identified as Pseudomonas resinovarans. The strain AST2.2 utilized chlorpyrifos as the sole source of carbon and energy. This strain exhibited growth upto 400mg/l concentration of chlorpyrifos and exhibited high extracellular organopho...

Isolation and characterization of a new Pseudomonas-related strain ...

African Journals Online (AJOL)

% with Pseudomonas putida (）AB680847). The phylogenetic tree formed by 16S rDNA sequences from both strain SKDP-1 and its most related bacteria also proved strain SKDP-1 to be one member of the genus Pseudomonas. Strain SKDP-1 ...

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

OpenAIRE

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 racemi...

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

Energy Technology Data Exchange (ETDEWEB)

Kumar, M. [Unidad de Biotecnologia del Petroleo, Centro de Biotecnologia, Fundacion Inst. de Estudios Avanzados (IDEA), Caracas (Venezuela); Synthesis and Biotics Div., Indian Oil Corp., Research and Development Center, Haryana (India); Leon, V.; Materano, A.D.S.; Ilzins, O.A.; Galindo-Castro, I.; Fuenmayor, S.L. [Unidad de Biotecnologia del Petroleo, Centro de Biotecnologia, Fundacion Inst. de Estudios Avanzados (IDEA), Caracas (Venezuela)

2006-03-15

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{sup -1} to 35.4 dN cm{sup -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. (orig.)

Regional analysis of potential polychlorinated biphenyl degrading bacterial strains from China

Directory of Open Access Journals (Sweden)

Jianjun Shuai

Full Text Available ABSTRACT Polychlorinated biphenyls (PCBs, the chlorinated derivatives of biphenyl, are one of the most prevalent, highly toxic and persistent groups of contaminants in the environment. The objective of this study was to investigate the biodegradation of PCBs in northeastern (Heilongjiang Province, northern (Shanxi Province and eastern China (Shanghai municipality. From these areas, nine soil samples were screened for PCB-degrading bacteria using a functional complementarity method. The genomic 16S rDNA locus was amplified and the products were sequenced to identify the bacterial genera. Seven Pseudomonas strains were selected to compare the capacity of bacteria from different regions to degrade biphenyl by HPLC. Compared to the biphenyl content in controls of 100%, the biphenyl content went down to 3.7% for strain P9-324, 36.3% for P2-11, and 20.0% for the other five strains. These results indicate that a longer processing time led to more degradation of biphenyl. PCB-degrading bacterial strains are distributed differently in different regions of China.

Antimicrobial properties of Pseudomonas strains producing the antibiotic mupirocin.

Science.gov (United States)

Matthijs, Sandra; Vander Wauven, Corinne; Cornu, Bertrand; Ye, Lumeng; Cornelis, Pierre; Thomas, Christopher M; Ongena, Marc

2014-10-01

Mupirocin is a polyketide antibiotic with broad antibacterial activity. It was isolated and characterized about 40 years ago from Pseudomonas fluorescens NCIMB 10586. To study the phylogenetic distribution of mupirocin producing strains in the genus Pseudomonas a large collection of Pseudomonas strains of worldwide origin, consisting of 117 Pseudomonas type strains and 461 strains isolated from different biological origins, was screened by PCR for the mmpD gene of the mupirocin gene cluster. Five mmpD(+) strains from different geographic and biological origin were identified. They all produced mupirocin and were strongly antagonistic against Staphylococcus aureus. Phylogenetic analysis showed that mupirocin production is limited to a single species. Inactivation of mupirocin production leads to complete loss of in vitro antagonism against S. aureus, except on certain iron-reduced media where the siderophore pyoverdine is responsible for the in vitro antagonism of a mupirocin-negative mutant. In addition to mupirocin some of the strains produced lipopeptides of the massetolide group. These lipopeptides do not play a role in the observed in vitro antagonism of the mupirocin producing strains against S. aureus. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Concurrent Haloalkanoate Degradation and Chlorate Reduction by Pseudomonas chloritidismutans AW-1T.

Science.gov (United States)

Peng, Peng; Zheng, Ying; Koehorst, Jasper J; Schaap, Peter J; Stams, Alfons J M; Smidt, Hauke; Atashgahi, Siavash

2017-06-15

Haloalkanoates are environmental pollutants that can be degraded aerobically by microorganisms producing hydrolytic dehalogenases. However, there is a lack of information about the anaerobic degradation of haloalkanoates. Genome analysis of Pseudomonas chloritidismutans AW-1 T , a facultative anaerobic chlorate-reducing bacterium, showed the presence of two putative haloacid dehalogenase genes, the l-DEX gene and dehI , encoding an l-2-haloacid dehalogenase (l-DEX) and a halocarboxylic acid dehydrogenase (DehI), respectively. Hence, we studied the concurrent degradation of haloalkanoates and chlorate as a yet-unexplored trait of strain AW-1 T The deduced amino acid sequences of l-DEX and DehI revealed 33 to 37% and 26 to 86% identities with biochemically/structurally characterized l-DEX and the d- and dl-2-haloacid dehalogenase enzymes, respectively. Physiological experiments confirmed that strain AW-1 T can grow on chloroacetate, bromoacetate, and both l- and d-α-halogenated propionates with chlorate as an electron acceptor. Interestingly, growth and haloalkanoate degradation were generally faster with chlorate as an electron acceptor than with oxygen as an electron acceptor. In line with this, analyses of l-DEX and DehI dehalogenase activities using cell-free extract (CFE) of strain AW-1 T grown on dl-2-chloropropionate under chlorate-reducing conditions showed up to 3.5-fold higher dehalogenase activity than the CFE obtained from AW-1 T cells grown on dl-2-chloropropionate under aerobic conditions. Reverse transcription-quantitative PCR showed that the l-DEX gene was expressed constitutively independently of the electron donor (haloalkanoates or acetate) or acceptor (chlorate or oxygen), whereas the expression of dehI was induced by haloalkanoates. Concurrent degradation of organic and inorganic halogenated compounds by strain AW-1 T represents a unique metabolic capacity in a single bacterium, providing a new piece of the puzzle of the microbial halogen cycle

Biodegradation of Mixed PAHs by PAH-Degrading Endophytic Bacteria

Directory of Open Access Journals (Sweden)

Xuezhu Zhu

2016-08-01

Full Text Available 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(apyrene (B(aP 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(aP, and strain P3 degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(aP. 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.

Prokaryotic Homologs of the Eukaryotic 3-Hydroxyanthranilate 3,4-Dioxygenase and 2-Amino-3-Carboxymuconate-6-Semialdehyde Decarboxylase in the 2-Nitrobenzoate Degradation Pathway of Pseudomonas fluorescens Strain KU-7†

OpenAIRE

Muraki, Takamichi; Taki, Masami; Hasegawa, Yoshie; Iwaki, Hiroaki; Lau, Peter C. K.

2003-01-01

The 2-nitrobenzoic acid degradation pathway of Pseudomonas fluorescens strain KU-7 proceeds via a novel 3-hydroxyanthranilate intermediate. In this study, we cloned and sequenced a 19-kb DNA locus of strain KU-7 that encompasses the 3-hydroxyanthranilate meta-cleavage pathway genes. The gene cluster, designated nbaEXHJIGFCDR, is organized tightly and in the same direction. The nbaC and nbaD gene products were found to be novel homologs of the eukaryotic 3-hydroxyanthranilate 3,4-dioxygenase a...

Degradation of naphthalene and fluorene by radiolysis using accelerated electrons

International Nuclear Information System (INIS)

Flores de Jesus, I.

2003-01-01

The volume of the dangerous wastes in global level is causing the poisoning of planet and all of the ecosystems, degrading the life level of millions of humans and causing serious problems in the public health. Since a years ago the volumes of organic effluents generated by the few industry and small populations were so tiny that a natural debugger process in a time and space delimited, acquiring again their natural characteristics and they could be used again. Nowadays these wastes are so numerous and precise in some cases that the capacity of natural purification in the receiving channel is not enough, in addition to the difficulty to treat them in conventional processes, this leads to the decrease in the water's quality making impossible its future use and causing with this a serious ecological problem. This fact has motivated the development of measures that tend to the conservation of the environment and in consequence, the development of debugger technologies with no generation of sub products that often are more dangerous than the originals, due to the previous thing, the treatment by means of radiation of the water is impelled since is a method that allows to degrade or to eliminate in simultaneous form pathogenic microorganisms and organic substances. The radiation by means of electrons beams is a method of advanced treatment who allows to degrade organic compounds, transforming them in compounds with less molecular weight, and in the best of the cases until its oxidation to carbon dioxide and water. In the present thesis the objective is the study of naphthalene and fluorene degradation by means of radiation with electron beams, establishing the operating conditions of the accelerator of Pelletron type. This research is supported by the Instituto Nacional de Investigaciones Nucleares, of a joint way with a series of antecedents in this subject, established in previous research with respect to the treatment of residual waters in a great scale, giving

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Enhanced hydrocarbon biodegradation by a newly isolated bacillus subtilis strain

International Nuclear Information System (INIS)

Christova, N.; Tuleva, B.; Nikolova-Damyanova, B.

2004-01-01

The relation between hydrocarbon degradation and biosurfactant (rhamnolipid) production by a new bacillus subtilis 22BN strain was investigated. The strain was isolated for its capacity to utilize n-hexadecane and naphthalene and at the same time to produce surface-active compound at high concentrations (1.5 - 2.0 g l -1 ). Biosurfactant production was detected by surface tension lowering and emulsifying activity. The strain is a good degrader of both hydrocarbons used with degradability of 98.3 ± 1% and 75 ± 2% for n-hexadecane and naphthalene, respectively. Measurement of cell hydrophobicity showed that the combination of slightly soluble substrate and rhamnolipid developed higher hydrophobicity correlated with increased utilization of both hydrocarbon substrates. To our knowledge, this is the first report of bacillus subtilis strain that degrades hydrophobic compounds and at the same time produces rhamnolipid biosurfactant. (orig.)

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

Science.gov (United States)

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...

A Pseudomonas putida strain genetically engineered for 1,2,3-trichloropropane bioremediation.

Science.gov (United States)

Samin, Ghufrana; Pavlova, Martina; Arif, M Irfan; Postema, Christiaan P; Damborsky, Jiri; Janssen, Dick B

2014-09-01

1,2,3-Trichloropropane (TCP) is a toxic compound that is recalcitrant to biodegradation in the environment. Attempts to isolate TCP-degrading organisms using enrichment cultivation have failed. A potential biodegradation pathway starts with hydrolytic dehalogenation to 2,3-dichloro-1-propanol (DCP), followed by oxidative metabolism. To obtain a practically applicable TCP-degrading organism, we introduced an engineered haloalkane dehalogenase with improved TCP degradation activity into the DCP-degrading bacterium Pseudomonas putida MC4. For this purpose, the dehalogenase gene (dhaA31) was cloned behind the constitutive dhlA promoter and was introduced into the genome of strain MC4 using a transposon delivery system. The transposon-located antibiotic resistance marker was subsequently removed using a resolvase step. Growth of the resulting engineered bacterium, P. putida MC4-5222, on TCP was indeed observed, and all organic chlorine was released as chloride. A packed-bed reactor with immobilized cells of strain MC4-5222 degraded >95% of influent TCP (0.33 mM) under continuous-flow conditions, with stoichiometric release of inorganic chloride. The results demonstrate the successful use of a laboratory-evolved dehalogenase and genetic engineering to produce an effective, plasmid-free, and stable whole-cell biocatalyst for the aerobic bioremediation of a recalcitrant chlorinated hydrocarbon. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

The Regulation of para-Nitrophenol Degradation in Pseudomonas putida DLL-E4.

Directory of Open Access Journals (Sweden)

Qiongzhen Chen

Full Text Available Pseudomonas putida DLL-E4 can efficiently degrade para-nitrophenol and its intermediate metabolite hydroquinone. The regulation of para-nitrophenol degradation was studied, and PNP induced a global change in the transcriptome of P. putida DLL-E4. When grown on PNP, the wild-type strain exhibited significant downregulation of 2912 genes and upregulation of 845 genes, whereas 2927 genes were downregulated and 891 genes upregulated in a pnpR-deleted strain. Genes related to two non-coding RNAs (ins1 and ins2, para-nitrophenol metabolism, the tricarboxylic acid cycle, the outer membrane porin OprB, glucose dehydrogenase Gcd, and carbon catabolite repression were significantly upregulated when cells were grown on para-nitrophenol plus glucose. pnpA, pnpR, pnpC1C2DECX1X2, and pnpR1 are key genes in para-nitrophenol degradation, whereas pnpAb and pnpC1bC2bDbEbCbX1bX2b have lost the ability to degrade para-nitrophenol. Multiple components including transcriptional regulators and other unknown factors regulate para-nitrophenol degradation, and the transcriptional regulation of para-nitrophenol degradation is complex. Glucose utilization was enhanced at early stages of para-nitrophenol supplementation. However, it was inhibited after the total consumption of para-nitrophenol. The addition of glucose led to a significant enhancement in para-nitrophenol degradation and up-regulation in the expression of genes involved in para-nitrophenol degradation and carbon catabolite repression (CCR. It seemed that para-nitrophenol degradation can be regulated by CCR, and relief of CCR might contribute to enhanced para-nitrophenol degradation. In brief, the regulation of para-nitrophenol degradation seems to be controlled by multiple factors and requires further study.

Mechanisms for naphthalene removal during electrolytic aeration.

Science.gov (United States)

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.

Biodegradation of naphthalene and phenanthren by Bacillus subtilis 3KP

Science.gov (United States)

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.

Transformation of carbon tetrachloride by Pseudomonas sp. strain KC under denitrification conditions

International Nuclear Information System (INIS)

Criddle, C.S.; DeWitt, J.T.; Grbic-Galic, D.; McCarty, P.L.

1990-01-01

A denitrifying Pseudomonas sp. (strain KC) capable of transforming carbon tetrachloride (CT) was isolated from groundwater aquifer solids. Major products of the transformation of 14 C-labeled CT by Pseudomonas strain KC under denitrification conditions were 14 CO 2 and an unidentified water-soluble fraction. Little or no chloroform was produced. Addition of dissolved trace metals, notably, ferrous iron and cobalt, to the growth medium appeared to enhance growth of Pseudomonas strain KC while inhibiting transformation of CT. It is hypothesized that transformation of CT by this organism is associated with the mechanism of trace-metal scavenging

ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING, PHENOL- AND CATECHOL-DEGRADING PSEUDOMONAS PUTIDA STRAIN AMR-12 IN SOILS FROM EGYPT

Directory of Open Access Journals (Sweden)

M. Abd. AbdEl-Mongy

2016-02-01

Full Text Available Sites contaminated with both heavy metals and organic xenobiotic pollutants warrants the effective use of either a multitude of bacterial degraders or bacteria having the capacity to detoxify numerous toxicants simultaneously. A molybdenum-reducing bacterium with the capacity to degrade phenolics is reported. Molybdenum (sodium molybdate reduction was optimum between pH 6.0 and 7.0 and between 20 and 30 °C. The most suitable electron donor was glucose. A narrow range of phosphate concentrations between 5.0 and 7.5 mM was required for optimal reduction, while molybdate between 20 and 30 mM were needed for optimal reduction. The scanning absorption spectrum of the molybdenum blue produced indicated that Mo-blue is a reduced phosphomolybdate. Molybdenum reduction was inhibited by the heavy metals mercury, silver and chromium. Biochemical analysis identified the bacterium as Pseudomonas putida strain Amr-12. Phenol and phenolics cannot support molybdenum reduction. However, the bacterium was able to grow on the phenolic compounds (phenol and catechol with observable lag periods. Maximum growth on phenol and catechol occurred around the concentrations of 600 mg∙L-1. The ability of this bacterium to detoxify molybdenum and grown on toxic phenolic makes this bacterium an important tool for bioremediation.

Enhancement of naphthalene tolerance in transgenic Arabidopsis plants overexpressing the ferredoxin-like protein (ADI1) from rice.

Science.gov (United States)

Fu, Xiao-Yan; Zhu, Bo; Han, Hong-Juan; Zhao, Wei; Tian, Yong-Sheng; Peng, Ri-He; Yao, Quan-Hong

2016-01-01

The ADI1 Arabidopsis plants enhanced tolerance and degradation efficiency to naphthalene and had great potential for phytoremediation of naphthalene in the plant material before composting or harvesting and removal. Naphthalene is a global environmental concern, because this substance is assumed to contribute considerably to human cancer risk. Cleaning up naphthalene contamination in the environment is crucial. Phytoremediation is an efficient technology to clean up contaminants. However, no gene that can efficiently degrade exogenous recalcitrant naphthalene in plants has yet been discovered. Ferredoxin (Fd) is a key player of biological electron transfer reaction in the PAH degradation process. The biochemical pathway for bacterial degradation of naphthalene has been well investigated. In this study, a rice gene, ADI1, which codes for a putative photosynthetic-type Fd, has been transformed into Arabidopsis thaliana. The transgenic Arabidopsis plants enhanced tolerance and degradation efficiency of naphthalene. Compared with wild-type plants, transgenic plants assimilated naphthalene from the culture media faster and removed more of this substance. When taken together, our findings suggest that breeding plants with overexpressed ADI1 gene is an effective strategy to degrade naphthalene in the environment.

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

Directory of Open Access Journals (Sweden)

Abd El-Latif Hesham

2014-01-01

Full Text Available 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.

Degradation and mineralization of the polycyclic aromatic hydrocarbons anthracene and naphthalene in intertidal marine sediments

International Nuclear Information System (INIS)

Bauer, J.E.; Capone, D.G.

1985-01-01

The degradation of the polynuclear aromatic hydrocarbons (PAHs) anthracene and naphthalene by the microbiota of intertidal sediments was investigated in laboratory studies. No mineralization of either PAH was observed in the absence of oxygen. Both rates and total amounts of PAH mineralization were strongly controlled by oxygen content and temperature of the incubations. Inorganic nitrogen and glucose amendments had minimal effects on PAH mineralization. The rates and total amounts of PAH mineralized were directly related to compound concentration, pre-exposure time, and concentration. Maximum mineralization was observed at the higher concentrations (5 to 100 μg/g [ppm]) of both PAHs. Optimal acclimation to anthracene and naphthalene (through pre-exposures to the compounds) occurred at the highest acclimation concentration (1,000 ppm). However, acclimation to a single concentration (100 ppm) resulted in initial relative mineralization rates over a range of re-exposure concentrations (1 to 1,000 ppm) being nearly identical. Maximum mineralization of both PAHs occurred after intermediate periods (1 to 2 weeks) of pre-exposure. The fraction of the total heterotrophic population capable of utilizing anthracene or naphthalene as sole carbon source was also greatest after 2 weeks

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

Science.gov (United States)

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...

40 CFR 180.1212 - Pseudomonas chlororaphis Strain 63-28; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pseudomonas chlororaphis Strain 63-28... RESIDUES IN FOOD Exemptions From Tolerances § 180.1212 Pseudomonas chlororaphis Strain 63-28; exemption... for residues of the microbial pesticide Pseudomonas chlororaphis Strain 63-28 in or on all food...

Effect of biosurfactant from two strains of Pseudomonas on ...

African Journals Online (AJOL)

Two Pseudomonas strains isolated from oil-contaminated soil which produce biosurfactant were studied. The biosurfactant containing broth formed stable emulsions with liquid light paraffin, cooking medium vegetable oil and toluene. The strains under study produce extra cellular biosurfactant in the culture media.

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

Directory of Open Access Journals (Sweden)

Gary S. Sayler

2012-02-01

Full Text Available 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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Production of metabolites from chloro biphenyls by resting cells of Pseudomonas strain LB400 after growth on different carbon sources

International Nuclear Information System (INIS)

Billingsley, K.A.; Ward, O.P.

1999-01-01

The transformation of polychlorinated biphenyl (PCB), when exposed to microorganisms, into chlorobenzoic acid metabolites was studied. PCBs are widely used in electrical transformers and have become widely dispersed in the environment. A proposed system for clean up of PCBs involves the combined use of anaerobic reductive dehalogenation of highly chlorinated congeners followed by aerobic degradation of moderately chlorinated PCBs, mediated by oxidative ring attack. Much of this work focused on biphenyl-grown cells, in particular Pseudomonas strain LB400 grown on biphenyl, which contains a multicomponent enzyme system. It was shown that resting cells of Pseudomonas strain LB400, grown on glycerol or glucose, could also transform purified PCB congeners and mixtures of PCBs in Aroclors, however, transformation rates were less than those observed with biphenyl-grown cells. 29 refs., 2 tabs., 2 figs

40 CFR 180.1200 - Pseudomonas fluorescens strain PRA-25; temporary exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pseudomonas fluorescens strain PRA-25... RESIDUES IN FOOD Exemptions From Tolerances § 180.1200 Pseudomonas fluorescens strain PRA-25; temporary... established for residues of the microbial pesticide, pseudomonas fluorescens strain PRA-25 when used on peas...

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

Science.gov (United States)

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.

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

OpenAIRE

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-?-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.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

ANOMALOUS BLUE COLOURING OF MOZZARELLA CHEESE INTENTIONALLY CONTAMINATED WITH PIGMENT PRODUCING STRAINS OF PSEUDOMONAS FLUORESCENS

Directory of Open Access Journals (Sweden)

P. Sechi

2011-04-01

Full Text Available In summer 2010 a large outbreak of anomalous blue coloration of mozzarella cheese was recorded in Italy and some northern European countries. Official laboratory analysis and health authorities linked the outbreak to the contamination of processing water with strains of Pseudomonas fluorescens, although several expert raised the question of how to unequivocally link the blue coloring to the presence of the micro-organism. In an attempt to set-up a method to determine whether a given Pseudomonas spp. strain is responsible of the defect, an in vitro system for the evaluation of blue colouring of mozzarella cheese intentionally contaminated with strains of Pseudomonas fluorescens. was developed The system is aimed to ascertain whether P. fluorescens strains, isolated from mozzarella cheese with anomalous blue coloration, are able to reproduce the blue coloration under controlled experimental condition. 96 trials of experimental inoculation of mozzarella cheese in different preservation liquids, were conducted using various suspension of Pseudomonas spp. (P. fluorescens ATCC 13525, P. fluorescens CFBP 3150, one P. fluorescens field strain isolated from blue-colored mozzarella cheese and P. aeruginosa ATCC 10145 as positive control at different concentrations and incubated at different temperatures. Growth curve of all Pseudomonas spp. strains tested demonstrated that after three days of incubation the concentration was generally higher than 106 CFU/g of mozzarella cheese incubated in Tryptic Soy Broth (TSB, and higher than 105 CFU/g of mozzarella cheese incubated in preservation liquid. All mozzarella cheeses inoculated with the field strain of Pseudomonas fluorescens showed the characteristic anomalous blue coloration, which is often associated with Pseudomonas fluorescens contamination of water used during mozzarella cheesemaking. With the proposed system, which enabled a considerable amount of samples to be analysed under controlled experimental

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

KAUST Repository

Stabler, R. A.

2013-01-24

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.

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.

Science.gov (United States)

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.

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

KAUST Repository

Stabler, R. A.; Negus, D.; Pain, Arnab; Taylor, P. 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.

Biodegradation of naphthalene from nonaqueous-phase liquids

International Nuclear Information System (INIS)

Ghoshal, S.; Luthy, R.G.; Ramaswami, A.

1995-01-01

Dissolution of polycyclic aromatic hydrocarbons (PAHs) from a non-aqueous-phase liquid (NAPL) to the aqueous phase renders these compounds bioavailable to microorganisms. Subsequent biodegradation of organic phase PAH then results in a depletion of PAH from the NAPL. This study focuses on identifying the rate-controlling processes affecting naphthalene biomineralization from a complex multicomponent NAPL, coal tar, and a simple two-component NAPL. A simplified dissolution degradation model is presented to identify quantitative criteria to assess whether mass transfer or biokinetic limitations control the overall rate of biotransformation of PAH compounds. Results show that the rate of mass transfer may control the overall rate of biotransformation in certain systems. Mass transfer does not limit biodegradation in slurry systems when coal tar is distributed in the micropores of a large number of small microporous silica particles. The end points of naphthalene degradation from the NAPLs have been evaluated, and results suggest that depletion of a significant mass of naphthalene from the NAPL phase is possible

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

Science.gov (United States)

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.

Degradation of Uniquely Glycosylated Secretory Immunoglobulin A in Tears From Patients With Pseudomonas aeruginosa Keratitis

DEFF Research Database (Denmark)

Lomholt, Jeanet Andersen; Kilian, Mogens

2008-01-01

PURPOSE. To investigate the integrity of secretory IgA (S-IgA) in tear fluid during bacterial keratitis and to evaluate the significance of specific Pseudomonas aeruginosa extracellular proteases in the observed degradation of S-IgA. METHODS. The integrity of component chains of S-IgA in tear fluid...... from patients with keratitis caused by P. aeruginosa, Streptococcus group G, Moraxella catarrhalis, Staphylococcus aureus, coagulase-negative staphylococci, and the IgA1 protease-producing Streptococcus pneumoniae were compared with S-IgA in tear fluid, colostrum, and saliva from healthy individuals......, and with tear S-IgA incubated with clinical isolates and genetically engineered P. aeruginosa strains with different protease profiles. Degradation of S-IgA and the significance of its glycosylation were analyzed in Western blots developed with antibodies against individual chains of S-IgA. RESULTS. Secretory...

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

Directory of Open Access Journals (Sweden)

Yi-Bin Qi

2017-02-01

Full Text Available 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(apyrene 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.

Synthesis of N and La co-doped TiO{sub 2}/AC photocatalyst by microwave irradiation for the photocatalytic degradation of naphthalene

Energy Technology Data Exchange (ETDEWEB)

Liu, Dandan; Wu, Zhansheng, E-mail: wuzhans@126.com; Tian, Fei; Ye, Bang-Ce; Tong, Yanbin, E-mail: tongyanbin@sina.com

2016-08-15

La and N co-doped TiO{sub 2} nanoparticles supported on activated carbon (TiO{sub 2}/AC) were synthesized through a microwave-assisted sol–gel method for the synergistic removal of naphthalene solution by photocatalytic degradation. Results showed that the La and N ions were incorporated into the TiO{sub 2} framework in both the anatase and rutile phases of TiO{sub 2} for single doped and co-doped samples, which narrowed the band gap of TiO{sub 2} from 2.82 to 2.20 eV. The PL spectra of the samples showed a decrease in the recombination centers when N and La were introduced in TiO{sub 2}/AC. The 0.001La-N-TiO{sub 2}/AC photocatalyst exhibited the highest degradation efficiency of 93.5% for naphthalene under visible light within 120 min. This result was attributed to a synergistic effect involving the efficient inhibition of the recombination of photogenerated electrons and holes, the increase in surface hydroxyl, surface area, volume pores, and the increase of uptake in the visible light region. In addition, the high apparent rate constant indicated that La and N co-doping result in the increase of photoactivity. This study demonstrated the co-doped TiO{sub 2}/AC is a highly efficient photocatalyst for the removal of naphthalene. The results provided valuable information on the mechanism of naphthalene decomposition. - Highlights: • N, La codoped TiO{sub 2}/AC catalysts were synthesized by microwave-assisted. • N and La doping inhibit the recombination of photogenerated electrons and holes. • 0.001La-N-TiO{sub 2}/AC obtains photodegradation efficiency of 93.5% for naphthalene. • The photocatalysts possess good photochemical stability and reusability.

Efficacy of selected Pseudomonas strains for biocontrol of Rhizoctonia solani in potato

Directory of Open Access Journals (Sweden)

Moncef MRABET

2014-01-01

Full Text Available Thirty seven bacterial isolates from faba bean (Vicia faba L. root-nodules were screened for their antagonistic activity against eight Rhizoctonia solani strains isolated from infected potato (Solanum tuberosum L. tubers. Two bacterial strains (designated as Kl.Fb14 and S8.Fb11 gave 50% in vitro inhibition of R. solani mycelial growth. 16S rDNA sequence analysis indicated that strain Kl.Fb14 exhibited 99.5% identity with Pseudomonas moraviensis, and that S8.Fb11 exhibited 99.8% identity with Pseudomonas reinekei. Greenhouse trials in soil showed that strain S8.Fb11 reduced the percentage of sclerotia on potato tubers and amounts of tuber infection for the potato cultivars Spunta and Nicola. In a field trial conducted in South Tunisia, infection with R. solani reduced potato yield by approximately 40% for ‘Spunta’ and 17% for ‘Nicola’; about 20% of the total tuber production was severely infected. However, when potato tubers were treated with strain S8.Fb11 prior to sowing, disease incidence was reduced to 6% of total production with low infection levels; potato yield was enhanced by about 6 kg per 10 m row in comparison to R. solani infected plants. The second selected Pseudomonas sp. (strain Kl.Fb14 did not affect either the levels of sclerotia on tubers or potato yield.

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

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Ewa M. Furmanczyk

2017-11-01

Full Text Available 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

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

Science.gov (United States)

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.

Biosurfactant and enzyme mediated crude oil degradation by Pseudomonas stutzeri NA3 and Acinetobacter baumannii MN3.

Science.gov (United States)

Parthipan, Punniyakotti; Elumalai, Punniyakotti; Sathishkumar, Kuppusamy; Sabarinathan, Devaraj; Murugan, Kadarkarai; Benelli, Giovanni; Rajasekar, Aruliah

2017-10-01

The present study focuses on the optimization of biosurfactant (BS) production using two potential biosurfactant producer Pseudomonas stutzeri NA3 and Acinetobacter baumannii MN3 and role of enzymes in the biodegradation of crude oil. The optimal conditions for P. stutzeri NA3 and A. baumannii MN3 for biodegradation were pH of 8 and 7; temperature of 30 and 40 °C, respectively. P. stutzeri NA3 and A. baumannii MN3 produced 3.81 and 4.68 g/L of BS, respectively. Gas chromatography mass spectrometry confirmed that BS was mainly composed of fatty acids. Furthermore, the role of the degradative enzymes, alkane hydroxylase, alcohol dehydrogenase and laccase on biodegradation of crude oil are explained. Maximum biodegradation efficiency (BE) was recorded for mixed consortia (86%) followed by strain P. stutzeri NA3 (84%). Both bacterial strains were found to be vigorous biodegraders of crude oil than other biosurfactant-producing bacteria due to their enzyme production capabilities and our results suggests that the bacterial isolates can be used for effective degradation of crude oil within short time periods.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Stimulation of diesel degradation and biosurfactant production by aminoglycosides in a novel oil-degrading bacterium Pseudomonas luteola PRO23

Directory of Open Access Journals (Sweden)

Atanasković Iva M.

2016-01-01

Full Text Available Bioremediation is promising technology for dealing with oil hydrocarbons contamination. In this research growth kinetics and oil biodegradation efficiency of Pseudomonas luteola PRO23, isolated from crude oil-contaminated soil samples, were investigated under different concentrations (5, 10 and 20 g/L of light and heavy crude oil. More efficient biodegradation and more rapid adaptation and cell growth were obtained in conditions with light oil. The 5 to 10 g/L upgrade of light oil concentration stimulated the microbial growth and the biodegradation efficiency. Further upgrade of light oil concentration and the upgrade of heavy oil concentration both inhibited the microbial growth, as well as biodegradation process. Aminoglycosides stimulated biosurfactant production in P. luteola in the range of sub-inhibitory concentrations (0.3125, 0.625 μg/mL. Aminoglycosides also induced biofilm formation. The production of biosurfactants was the most intense during lag phase and continues until stationary phase. Aminoglycosides also induced changes in P. luteola growth kinetics. In the presence of aminoglycosides this strain degraded 82% of diesel for 96 h. These results indicated that Pseudomonas luteola PRO23 potentially can be used in bioremediation of crude oil-contaminated environments and that aminoglycosides could stimulate this process. [Projekat Ministarstva nauke Republike Srbije, br. TR31080

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

Directory of Open Access Journals (Sweden)

Tengxia He

2018-01-01

Full Text Available 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.

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

Science.gov (United States)

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

The isolation and functional identification on producing cellulase of Pseudomonas mendocina

Science.gov (United States)

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

Identification of novel transaminases from a 12-aminododecanoic acid-metabolizing Pseudomonas strain.

Science.gov (United States)

Wilding, Matthew; Walsh, Ellen F A; Dorrian, Susan J; Scott, Colin

2015-07-01

A Pseudomonas species [Pseudomonas sp. strain amino alkanoate catabolism (AAC)] was identified that has the capacity to use 12-aminododecanoic acid, the constituent building block of homo-nylon-12, as a sole nitrogen source. Growth of Pseudomonas sp. strain AAC could also be supported using a range of additional ω-amino alkanoates. This metabolic function was shown to be most probably dependent upon one or more transaminases (TAs). Fourteen genes encoding putative TAs were identified from the genome of Pseudomonas sp. AAC. Each of the 14 genes was cloned, 11 of which were successfully expressed in Escherichia coli and tested for activity against 12-aminododecanoic acid. In addition, physiological functions were proposed for 9 of the 14 TAs. Of the 14 proteins, activity was demonstrated in 9, and of note, 3 TAs were shown to be able to catalyse the transfer of the ω-amine from 12-aminododecanoic acid to pyruvate. Based on this study, three enzymes have been identified that are promising biocatalysts for the production of nylon and related polymers. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Comparison of 432 Pseudomonas strains through integration of genomic, functional, metabolic and expression data

NARCIS (Netherlands)

Koehorst, Jasper J.; Dam, van Jesse C.J.; Heck, van Ruben G.A.; Saccenti, Edoardo; Martins dos Santos, Vitor; Suarez-Diez, Maria; Schaap, Peter J.

2016-01-01

Pseudomonas is a highly versatile genus containing species that can be harmful to humans and plants while others are widely used for bioengineering and bioremediation. We analysed 432 sequenced Pseudomonas strains by integrating results from a large scale functional comparison using protein

Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa.

Science.gov (United States)

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Comparison of some indigenous bacterial strains of pseudomonas ssp. for production of biosurfactants

International Nuclear Information System (INIS)

Sahafeeq, M.; Kokub, D.; Khalid, Z.M.; Malik, K.A.

1991-01-01

Some indigenous pseudomonas spp. were found to have the ability of emulsification, lowering the surface and interfacial tensions, and formation of high reciprocal CMCs. Six strains of Pseudomonas spp were compared for biosurfactant production grown on hexadecane. Supernatant from whole culture broth of these strains could lower surface tension from 65 mN/m to 28-32 nM/m, interfacial tension from 40 nM/m to 1-3 mN/m and had high reciprocal CMCs. When compared for emulsification ability by the culture broth of these strains, the emulsification index (E24) was found to range between 60-65. Biosurfactant containing culture broth of some strains could retain the property up to 80 C, pH of 13 and sodium chloride concentration for 17% which indicates their possible role in some depleted oil well. (author)

Evaluation of the effects of a polyurethane carrier on the degradation of chlorinated anilines by Pseudomonas acidovorans CA50

International Nuclear Information System (INIS)

Loidl, M.; Stockinger, J.; Hinteregger, C.; Streichsbier, F.

1994-01-01

A previously described model system for the treatment of harzardous chloroaniline-containing waste waters using immobilized bacterial cells in a bioreactor was enhanced in its degradation efficiency. This was achieved by the substitution of the calcium alginate beads by an inert polyurethane (PU)-carrier. The supply of chloroaniline-polluted waste waters with the PU-carrier (1.25% w/v) resulted in a distinct decrease of the pollutant concentrations in the solution due to the effects of adsorption. Nevertheless, the initially bound amounts of the chloroanilines, were also degraded, which was proved by the chloride balance. In comparative batch-degradation experiments with the Pseudomonas acidovorans strain CA50 with and without the addition of the PU-carrier (1.25% v/w), respectively, the advantages of the PU-supplied treatment system were demonstrated; among others a marked shortening of the degradation periods was achieved. The advantage of the PU-carrier was also shown by using a bubble reactor. In this connection, it is particularly worth mentioning, that high degradation rates can be achieved for a long time even for strongly persistent pollutants. (orig.)

[Physicochemical and microbiological factors influencing the bioavailability of organic contaminants in subsoils

International Nuclear Information System (INIS)

1992-01-01

We report progress in elucidating the microbiological variables important in determining the relative success of bacteria in utilizing soil-sorbed contaminants. Two bacterial species, Pseudomonas putida (ATCC 17484) and an Alcaligenes sp. isolated from petroleum contaminated soil are known to differ markedly in their ability to utilize soil-sorbed napthalene based on a kinetic comparison of their capability of naphthalene mineralization in soil-containing and soil-free systems. The kinetic analysis led us to conclude that strain 17484 had direct access to naphthalene present in a labile sorbed state which promoted the rapid desorption of naphthalene from the non-labile phase. Conversely, both the rate and extent of naphthalene mineralization by strain NP-Alk suggested that this organism had access only to naphthalene in solution. Desorption was thus limited and the efficiency of total naphthalene removal from these soil slurries was poor. These conclusions were based on the average activities of cells in soil slurries without regard for the disposition of the organisms with respect to the sorbent. Since both organisms degrade naphthalene by apparently identical biochemical pathways, have similar enzyme kinetic properties, and are both motile, gram negative organisms, we undertook a series of investigations to gain a better understanding of what microbiological properties were important in bioavailability

Microbial degradation of resins fractionated from Arabian light crude oil

International Nuclear Information System (INIS)

Venkateswaran, K.; Hoaki, T.; Kato, M.; Maruyama, T.

1995-01-01

Sediment samples from the Japanese coasts were screened for microorganisms able to degrade resin components of crude oil. A mixed population that could degrade 35% of 5000 ppm resin in 15 days was obtained. This population also metabolized 50% of saturates and aromatics present in crude oil (5000 ppm) in 7 days. A Pseudomonas sp., isolated from the mixed population, emulsified and degraded 30% of resins. It also degraded saturates and aromatics (30%) present in crude oil (5000 ppm). These results were obtained from Iatroscan analysis. Degradation of crude oil was also analyzed by gas chromatography (GC). The peaks corresponding to known aliphatic hydrocarbons in crude oil greatly decreased within the first two days of incubation in the cultures of the RY-mixed population and of Pseudomonas strain UN3. Aromatic compounds detected as a broad peak by GC were significantly degraded at day 7 by Pseudomonas strain UN3, and at day 15 by the RY-mixed population. Investigations are ongoing to determine the genetic basis for the ability of these organisms to grow on the resin fractions of crude oil as a sole source of carbon and energy. 28 refs., 4 figs., 1 tab

Molecular Characterization of the Genes pcaG and pcaH, Encoding Protocatechuate 3,4-Dioxygenase, Which Are Essential for Vanillin Catabolism in Pseudomonas sp. Strain HR199

Science.gov (United States)

Overhage, Jörg; Kresse, Andreas U.; Priefert, Horst; Sommer, Horst; Krammer, Gerhard; Rabenhorst, Jürgen; Steinbüchel, Alexander

1999-01-01

Pseudomonas sp. strain HR199 is able to utilize eugenol (4-allyl-2-methoxyphenol), vanillin (4-hydroxy-3-methoxybenzaldehyde), or protocatechuate as the sole carbon source for growth. Mutants of this strain which were impaired in the catabolism of vanillin but retained the ability to utilize eugenol or protocatechuate were obtained after nitrosoguanidine mutagenesis. One mutant (SK6169) was used as recipient of a Pseudomonas sp. strain HR199 genomic library in cosmid pVK100, and phenotypic complementation was achieved with a 5.8-kbp EcoRI fragment (E58). The amino acid sequences deduced from two corresponding open reading frames (ORF) identified on E58 revealed high degrees of homology to pcaG and pcaH, encoding the two subunits of protocatechuate 3,4-dioxygenase. Three additional ORF most probably encoded a 4-hydroxybenzoate 3-hydroxylase (PobA) and two putative regulatory proteins, which exhibited homology to PcaQ of Agrobacterium tumefaciens and PobR of Pseudomonas aeruginosa, respectively. Since mutant SK6169 was also complemented by a subfragment of E58 that harbored only pcaH, this mutant was most probably lacking a functional β subunit of the protocatechuate 3,4-dioxygenase. Since this mutant was still able to grow on protocatechuate and lacked protocatechuate 4,5-dioxygenase and protocatechuate 2,3-dioxygenase, the degradation had to be catalyzed by different enzymes. Two other mutants (SK6184 and SK6190), which were also impaired in the catabolism of vanillin, were not complemented by fragment E58. Since these mutants accumulated 3-carboxy muconolactone during cultivation on eugenol, they most probably exhibited a defect in a step of the catabolic pathway following the ortho cleavage. Moreover, in these mutants cyclization of 3-carboxymuconic acid seems to occur by a syn absolute stereochemical course, which is normally only observed for cis,cis-muconate lactonization in pseudomonads. In conclusion, vanillin is degraded through the ortho-cleavage pathway

Inhibition of food-related bacteria by antibacterial substances produced by Pseudomonas sp. strains isolated from pasteurized milk

Directory of Open Access Journals (Sweden)

Ana Beatriz Ferreira Rangel

2013-12-01

Full Text Available In this work, the production of antimicrobial substances by strains of Pseudomonas sp. isolated from pasteurized milk and their potential action against food-related bacteria were investigated. Samples of pasteurized milk were purchased from arbitrarily chosen commercial establishments in the city of Rio de Janeiro, Brazil. Of the four samples analyzed, three presented several typical colonies of Pseudomonas. About 100 colonies were chosen and subjected to biochemical tests for confirmation of their identity. Eighteen strains of the Pseudomonas genus were identified and submitted to tests for the production of antimicrobial substances. Twelve strains (66.7% were identified as Pseudomonas fluorescens, four (22.2% as P. aeruginosa, one (5.5% as P. mendocina and one (5.5% as P. pseudoalcaligenes. Only two P. fluorescens strains were unable to produce any antimicrobial substance against any of the indicator strains tested. Most of the strains presented a broad spectrum of action, inhibiting reference and food-related strains such as Proteus vulgaris, Proteus mirabilis, Hafnia alvei, Yersinia enterocolitica, Escherichia coli and Salmonella typhi. Five antimicrobial substance-producing strains, which presented the broadest spectrum of action, were also tested against Staphylococcus aureus reference strains and 26 Staphylococcus sp. strains isolated from foods, some of which were resistant to antibiotics. The producer strains 8.1 and 8.3, both P. aeruginosa, were able to inhibit all the staphylococcal strains tested. The antimicrobial substances produced by strains 8.1 and 8.3 did not seem to be typical bacteriocins, since they were resistant to the three proteolytic enzymes tested. Experiments involving the characterization of these substances are being carried out in order to evaluate their biotechnological application.

Catabolite repression and nitrogen control of allantoin-degrading enzymes in Pseudomonas aeruginosa

NARCIS (Netherlands)

Janssen, D.B.; Drift, C. van der

1983-01-01

The formation of the allantoin-degrading enzymes allantoinase, allantoicase and ureidoglycolase in Pseudomonas aeruginosa was found to be regulated by induction, catabolite repression and nitrogen control. Induction was observed when urate, allantoin or allantoate were included in the growth medium,

Isolation and identification of bacterial consortia responsible for degrading oil spills from the coastal area of Yanbu, Saudi Arabia

Directory of Open Access Journals (Sweden)

Amr Abd-EL Mooti EL Hanafy

2016-01-01

Full Text Available Twenty-three crude-oil-degrading bacteria were isolated from oil-contaminated sites near the Red Sea. Based on a high growth rate on crude oil and on hydrocarbon degradation ability, four strains were selected from the 23 isolated strains for further study. These four strains were selected on the basis of dichlorophenolindophenol assay. The nucleotide sequences of the 16S rRNA gene showed that these isolated strains belonged to genus Pseudomonas and Nitratireductor. Among the four isolates, strains S5 (Pseudomonas sp., 95% and 4b (Nitratireductor sp., 70% were the most effective ones in degrading crude oil. Using a spectrophotometer and gas chromatography–mass spectrometry, degradation of more than 90% of the crude oil was observed after two weeks of cultivation in Bushnell–Haas medium. The results showed that these strains have the ability to degrade crude oil and may be used for environmental remediation.

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

Science.gov (United States)

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.

Effectiveness of halo-tolerant, auxin producing Pseudomonas and Rhizobium strains to improve osmotic stress tolerance in mung bean (Vigna radiata L.

Directory of Open Access Journals (Sweden)

Maqshoof Ahmad

2013-12-01

Full Text Available Halo-tolerant, auxin producing bacteria could be used to induce salt tolerance in plants. A number of Rhizobium and auxin producing rhizobacterial strains were assessed for their ability to tolerate salt stress by conducting osmoadaptation assay. The selected strains were further screened for their ability to induce osmotic stress tolerance in mung bean seedlings under salt-stressed axenic conditions in growth pouch/jar trials. Three most effective strains of Rhizobium and Pseudomonas containing ACC-deaminase were evaluated in combination, for their ability to induce osmotic stress tolerance in mung bean at original, 4, and 6 dS m-1 under axenic conditions. Results showed that sole inoculation of Rhizobium and Pseudomonas strains improved the total dry matter up to 1.4, and 1.9 fold, respectively, while the increase in salt tolerance index was improved up to 1.3 and 2.0 fold by the Rhizobium and Pseudomonas strains, respectively. However, up to 2.2 fold increase in total dry matter and salt tolerance index was observed due to combined inoculation of Rhizobium and Pseudomonas strains. So, combined application of Rhizobium and Pseudomonas strains could be explored as an effective strategy to induce osmotic stress tolerance in mung bean.

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

Science.gov (United States)

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.

Synthesis and Antimicrobial Evaluation of 1-[(2-Substituted phenylcarbamoyl]naphthalen-2-yl Carbamates

Directory of Open Access Journals (Sweden)

Tomas Gonec

2016-09-01

Full Text Available Series of thirteen 1-[(2-chlorophenylcarbamoyl]naphthalen-2-yl carbamates and thirteen 1-[(2-nitrophenylcarbamoyl]naphthalen-2-yl carbamates with alkyl/cycloalkyl/arylalkyl chains were prepared and characterized. Primary in vitro screening of the synthesized compounds was performed against Staphylococcus aureus, two methicillin-resistant S. aureus strains, Mycobacterium marinum, and M. kansasii. 1-[(2-Chlorophenylcarbamoyl]naphthalen-2-yl ethylcarbamate and 1-[(2-nitrophenylcarbamoyl]naphthalen-2-yl ethylcarbamate showed antistaphylococcal (MICs = 42 µM against MRSA and antimycobacterial (MICs = 21 µM activity against the tested strains comparable with or higher than that of the standards ampicillin and isoniazid. In the case of bulkier carbamate tails (R > propyl/isopropyl, the activity was similar (MICs ca. 70 µM. Screening of the cytotoxicity of both of the most effective compounds was performed using THP-1 cells, and no significant lethal effect was observed (LD50 >30 µM. The structure-activity relationships are discussed.

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

Science.gov (United States)

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.

Isolation and identification of aromatic hydrocarbon degrading yeasts present in gasoline tanks of urbans vehicles

Directory of Open Access Journals (Sweden)

Nathalia Catalina Delgadillo-Ordoñez

2017-07-01

Full Text Available Yeast isolates were obtained from fuel tanks of vehicles in order to assess their potential use in the degradation of aromatic hydrocarbons. Growth assays were performed in minimum mineral medium using different aromatic hydrocarbons (benzene, toluene, naphthalene, phenanthrene, and pyrene as the sole carbon source. Isolates that showed growth in any of the tested polycyclic aromatic hydrocarbons were identified by Sanger sequencing of the ITS1 and ITS2 rDNA molecular markers. A total of 16 yeasts strains were isolated, and three showed remarkable growth in media with aromatic hydrocarbons as the sole carbon source. These strains belong to the genus Rhodotorula, and correspond to the species Rhodotorula calyptogenae (99,8% identity and Rhodotorula dairenensis (99,8% identity.  These strains grew in benzene, toluene, naphthalene, phenanthrene and pyrene. This study demonstrates for the first time that yeasts of the genus Rhodotorula inhabit pipelines and fuel tanks of vehicles and that remove   aromatic hydrocarbons that are environmental pollutants. Our results suggest that these yeasts are potential candidates for aromatic hydrocarbon degradation as part of bioremediation strategies.

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

Science.gov (United States)

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...

Pseudomonas lactis sp. nov. and Pseudomonas paralactis sp. nov., isolated from bovine raw milk.

Science.gov (United States)

von Neubeck, Mario; Huptas, Christopher; Glück, Claudia; Krewinkel, Manuel; Stoeckel, Marina; Stressler, Timo; Fischer, Lutz; Hinrichs, Jörg; Scherer, Siegfried; Wenning, Mareike

2017-06-01

Five strains, designated WS 4672T, WS 4998, WS 4992T, WS 4997 and WS 5000, isolated from bovine raw milk formed two individual groups in a phylogenetic analysis. The most similar species on the basis of 16S rRNA gene sequences were Pseudomonas azotoformans IAM 1603T, Pseudomonas gessardii CIP 105469T and Pseudomonas libanensis CIP 105460T showing 99.7-99.6 % similarity. Using rpoD gene sequences Pseudomonas veronii LMG 17761T (93.3 %) was most closely related to strain WS 4672T and Pseudomonas libanensis CIP 105460T to strain WS 4992T (93.3 %). The five strains could be differentiated from their closest relatives and from each other by phenotypic and chemotaxonomic characterization and ANIb values calculated from draft genome assemblies. ANIb values of strains WS 4992T and WS4671T to the closest relatives are lower than 90 %. The major cellular polar lipids of both strains are phosphatidylethanolamine, phosphatidylglycerol, a phospholipid and diphosphatidylglycerol, and their major quinone is Q-9. The DNA G+C content of strains WS 4992T and WS 4672T were 60.0  and 59.7  mol%, respectively. Based on these genotypic and phenotypic traits two novel species of the genus Pseudomonas are proposed: Pseudomonas lactis sp. nov. [with type strain WS 4992T (=DSM 29167T=LMG 28435T) and the additional strains WS 4997 and WS 5000], and Pseudomonasparalactis sp. nov. [with type strain WS 4672T (=DSM 29164T=LMG 28439T) and additional strain WS 4998].

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Ecofriendly biodegradation and detoxification of Reactive Red 2 textile dye by newly isolated Pseudomonas sp. SUK1

International Nuclear Information System (INIS)

Kalyani, D.C.; Telke, A.A.; Dhanve, R.S.; Jadhav, J.P.

2009-01-01

The aim of this work is to evaluate textile dyes degradation by novel bacterial strain isolated from the waste disposal sites of local textile industries. Detailed taxonomic studies identified the organisms as Pseudomonas species and designated as strain Pseudomonas sp. SUK1. The isolate was able to decolorize sulfonated azo dye (Reactive Red 2) in a wide range (up to 5 g l -1 ), at temperature 30 deg. C, and pH range 6.2-7.5 in static condition. This isolate also showed decolorization of the media containing a mixture of dyes. Measurements of COD were done at regular intervals to have an idea of mineralization, showing 52% reduction in the COD within 24 h. Induction in the activity of lignin peroxidase and azoreductase was observed during decolorization of Reactive Red 2 in the batch culture, which represented their role in degradation. The biodegradation was monitored by UV-vis, IR spectroscopy, HPLC. The final product, 2-naphthol was characterized by GC-mass spectroscopy. The phytotoxicity study revealed the degradation of Reactive Red 2 into non-toxic product by Pseudomonas sp. SUK1

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Science.gov (United States)

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

Science.gov (United States)

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-...

Pseudomonas helleri sp. nov. and Pseudomonas weihenstephanensis sp. nov., isolated from raw cow's milk.

Science.gov (United States)

von Neubeck, M; Huptas, C; Glück, C; Krewinkel, M; Stoeckel, M; Stressler, T; Fischer, L; Hinrichs, J; Scherer, S; Wenning, M

2016-03-01

Analysis of the microbiota of raw cow's milk and semi-finished milk products yielded seven isolates assigned to the genus Pseudomonas that formed two individual groups in a phylogenetic analysis based on partial rpoD and 16S rRNA gene sequences. The two groups could be differentiated from each other and also from their closest relatives as well as from the type species Pseudomonas aeruginosa by phenotypic and chemotaxonomic characterization and average nucleotide identity (ANIb) values calculated from draft genome assemblies. ANIb values within the groups were higher than 97.3 %, whereas similarity values to the closest relatives were 85 % or less. The major cellular lipids of strains WS4917T and WS4993T were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol; the major quinone was Q-9 in both strains, with small amounts of Q-8 in strain WS4917T. The DNA G+C contents of strains WS4917T and WS4993T were 58.08 and 57.30 mol%, respectively. Based on these data, strains WS4917T, WS4995 ( = DSM 29141 = LMG 28434), WS4999, WS5001 and WS5002 should be considered as representatives of a novel species of the genus Pseudomonas, for which the name Pseudomonas helleri sp. nov. is proposed. The type strain of Pseudomonas helleri is strain WS4917T ( = DSM 29165T = LMG 28433T). Strains WS4993T and WS4994 ( = DSM 29140 = LMG 28438) should be recognized as representing a second novel species of the genus Pseudomonas, for which the name Pseudomonas weihenstephanensis sp. nov. is proposed. The type strain of Pseudomonas weihenstephanensis is strain WS4993T ( = DSM 29166T = LMG 28437T).

Biosurfactant production by Pseudomonas strains isolated from floral nectar.

Science.gov (United States)

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.

Effect of pH and inoculum size on pentachlorophenol degradation ...

African Journals Online (AJOL)

The success of this depends on finding strains able to degrade PCP in a changeable environment. The aim of this work was to study the influence of pH of the medium and the effect of inoculum size on pentachlorophenol degradation by Pseudomonas sp. A study of PCP degradation kinetics was performed to assess such ...

Pseudomonas wadenswilerensis sp. nov. and Pseudomonas reidholzensis sp. nov., two novel species within the Pseudomonas putida group isolated from forest soil.

Science.gov (United States)

Frasson, David; Opoku, Michael; Picozzi, Tara; Torossi, Tanja; Balada, Stefanie; Smits, Theo H M; Hilber, Urs

2017-08-01

Within the frame of a biotechnological screening, we isolated two Pseudomonas strains from forest soil. 16S rRNA gene sequence analysis indicated that strain CCOS 864T shared 99.8 % similarity with Pseudomonas donghuensis HYST, while strain CCOS 865T shared 99.0 % similarity with Pseudomonas putida DSM 291T and lower similarity with other P. putida group type strains. Based on multilocus sequence analysis, the two strains were genotypically distinct from each other, each forming a separate clade. Strains CCOS 864T and CCOS 865T were Gram-stain-negative, motile and rod-shaped, growing at a temperature range of 4-37 °C. Strain CCOS 864T could be phenotypically distinguished from P. putida group species by the combination of gelatinase-positive reaction and positive growth on N-acetyl-d-glucosamine, p-hydroxyphenylacetic acid and inosine but lack of fluorescein production on King's B medium, while strain CCOS 865T could be distinguished from P. putida group species by the combination of positive growth with saccharic acid and negative growth with p-hydroxyphenylacetic acid and l-pyroglutamic acid. The major polar lipid for both strains was phosphatidylethanolamine; the major quinone was ubiquinone Q-9. DNA-DNA hybridization and average nucleotide identities confirmed the novel species status for the two strains. The DNA G+C contents of CCOS 864T and CCOS 865T were 62.1 and 63.8 mol%, respectively. The phenotypic, phylogenetic and DNA-DNA relatedness data support the suggestion that CCOS 864T and CCOS 865T represent two novel Pseudomonas species. The names Pseudomonas wadenswilerensis sp. nov. (type strain CCOS 864T=LMG 29327T) and Pseudomonas reidholzensis sp. nov. (type strain CCOS 865T=LMG 29328T) are proposed.

Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains

International Nuclear Information System (INIS)

Yousaf, Sohail; Afzal, Muhammad; Reichenauer, Thomas G.; Brady, Carrie L.; Sessitsch, Angela

2011-01-01

The genus Enterobacter comprises a range of beneficial plant-associated bacteria showing plant growth promotion. Enterobacter ludwigii belongs to the Enterobacter cloacae complex and has been reported to include human pathogens but also plant-associated strains with plant beneficial capacities. To assess the role of Enterobacter endophytes in hydrocarbon degradation, plant colonization, abundance and expression of CYP153 genes in different plant compartments, three plant species (Italian ryegrass, birdsfoot trefoil and alfalfa) were grown in sterile soil spiked with 1% diesel and inoculated with three endophytic E. ludwigii strains. Results showed that all strains were capable of hydrocarbon degradation and efficiently colonized the rhizosphere and plant interior. Two strains, ISI10-3 and BRI10-9, showed highest degradation rates of diesel fuel up to 68% and performed best in combination with Italian ryegrass and alfalfa. All strains expressed the CYP153 gene in all plant compartments, indicating an active role in degradation of diesel in association with plants. - Highlights: → E. ludwigii strains efficiently colonized plants in a non-sterile soil environment. → E. ludwigii strains efficiently expressed alkane degradation genes in plants. → E. ludwigii efficiently degraded alkane contaminations and promoted plant growth. → E. ludwigii interacted more effectively with Italian ryegrass than with other plants. → Degradation activity varied with plant and microbial genotype as well as with time. - Enterobacter ludwigii strains belonging to the E. cloacae complex are able to efficiently degrade alkanes when associated with plants and to promote plant growth.

Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains

Energy Technology Data Exchange (ETDEWEB)

Yousaf, Sohail [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); Afzal, Muhammad [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad (Pakistan); Reichenauer, Thomas G. [AIT Austrian Institute of Technology GmbH, Environmental Resources and Technologies Unit, A-2444 Seibersdorf (Austria); Brady, Carrie L. [Forestry and Agricultural Biotechnology Institute, Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria (South Africa); Sessitsch, Angela, E-mail: angela.sessitsch@ait.ac.at [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria)

2011-10-15

The genus Enterobacter comprises a range of beneficial plant-associated bacteria showing plant growth promotion. Enterobacter ludwigii belongs to the Enterobacter cloacae complex and has been reported to include human pathogens but also plant-associated strains with plant beneficial capacities. To assess the role of Enterobacter endophytes in hydrocarbon degradation, plant colonization, abundance and expression of CYP153 genes in different plant compartments, three plant species (Italian ryegrass, birdsfoot trefoil and alfalfa) were grown in sterile soil spiked with 1% diesel and inoculated with three endophytic E. ludwigii strains. Results showed that all strains were capable of hydrocarbon degradation and efficiently colonized the rhizosphere and plant interior. Two strains, ISI10-3 and BRI10-9, showed highest degradation rates of diesel fuel up to 68% and performed best in combination with Italian ryegrass and alfalfa. All strains expressed the CYP153 gene in all plant compartments, indicating an active role in degradation of diesel in association with plants. - Highlights: > E. ludwigii strains efficiently colonized plants in a non-sterile soil environment. > E. ludwigii strains efficiently expressed alkane degradation genes in plants. > E. ludwigii efficiently degraded alkane contaminations and promoted plant growth. > E. ludwigii interacted more effectively with Italian ryegrass than with other plants. > Degradation activity varied with plant and microbial genotype as well as with time. - Enterobacter ludwigii strains belonging to the E. cloacae complex are able to efficiently degrade alkanes when associated with plants and to promote plant growth.

Comparative study on the degradation of dibutyl phthalate by two newly isolated Pseudomonas sp. V21b and Comamonas sp. 51F

Directory of Open Access Journals (Sweden)

Vinay Kumar

2017-09-01

Full Text Available Dibutyl phthalate is (DBP the top priority toxicant responsible for carcinogenicity, teratogenicity and endocrine disruption. This study demonstrates the DBP degradation capability of the two newly isolated bacteria from municipal solid waste leachate samples. The isolated bacteria were designated as Pseudomonas sp. V21b and Comamonas sp. 51F after scanning electron microscopy, transmission electron microscopy, Gram-staining, antibiotic sensitivity tests, biochemical characterization, 16S-rRNA gene identification and phylogenetic studies. They were able to grow on DBP, benzyl butyl phthalate, monobutyl phthalate, diisodecyl phthalate, dioctyl phthalate, and protocatechuate. It was observed that Pseudomonas sp. V21b was more efficient in DBP degradation when compared with Comamonas sp. 51F. It degraded 57% and 76% of the initial DBP in minimal salt medium and in DBP contaminated samples respectively. Kinetics for the effects of DBP concentration on Pseudomonas sp. V21b and Comamonas sp. 51F growth was also evaluated. Stoichiometry for DBP degradation and biomass formation were compared for both the isolates. Two major metabolites diethyl phthalate and monobutyl phthalates were identified using GC–MS in the extracts. Key genes were amplified from the genomes of Pseudomonas sp. V21b and Comamonas sp. 51F. DBP degradation pathway was also proposed.

Repeated batch and continuous degradation of chlorpyrifos by Pseudomonas putida.

Science.gov (United States)

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.

Pseudomonas syringae evades host immunity by degrading flagellin monomers with alkaline protease AprA

NARCIS (Netherlands)

Pel, Michiel J C; van Dijken, Anja J H; Bardoel, Bart W; Seidl, Michael F; van der Ent, Sjoerd; van Strijp, Jos A G; Pieterse, Corné M J

Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of

Pseudomonas syringae evades host Immunity by degrading flagellin monomers with alkaline protease AprA

NARCIS (Netherlands)

Pel, M.J.C.; Van Dijken, A.J.H.; Bardoel, B.W.; Seidl, M.F; Van der Ent, S.; Van Strijp, J.A.G.

2014-01-01

Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of

Application of a luminescence-based biosensor for assessing naphthalene biodegradation in soils from a manufactured gas plant

International Nuclear Information System (INIS)

Paton, G.I.; Reid, B.J.; Semple, K.T.

2009-01-01

Despite numerous reviews suggesting that microbial biosensors could be used in many environmental applications, in reality they have failed to be used for which they were designed. In part this is because most of these sensors perform in an aqueous phase and a buffered medium, which is in contrast to the nature of genuine environmental systems. In this study, a range of non-exhaustive extraction techniques (NEETs) were assessed for (i) compatibility with a naphthalene responsive biosensor and (ii) correlation with naphthalene biodegradation. The NEETs removed a portion of the total soil naphthalene in the order of methanol > HPCD > βCD > water. To place the biosensor performance to NEETs in context, a biodegradation experiment was carried out using historically contaminated soils. By coupling the HPCD extraction with the biosensor, it was possible to assess the fraction of the naphthalene capable of undergoing microbial degradation in soil. - Exposure of microbial biosensors to cyclodextrin solutions allows the assessment of the degradable fraction of contaminants in soil.

Cometabolic Degradation of Trichloroethylene by Pseudomonas cepacia G4 in a Chemostat with Toluene as the Primary Substrate

NARCIS (Netherlands)

Landa, Andrew S.; Sipkema, E. Marijn; Weijma, Jan; Beenackers, Antonie A.C.M.; Dolfing, Jan; Janssen, Dick B.

Pseudomonas cepacia G4 is capable of cometabolic degradation of trichloroethylene (TCE) if the organism is grown on certain aromatic compounds. To obtain more insight into the kinetics of TCE degradation and the effect of TCE transformation products, we have investigated the simultaneous conversion

Draft Genome Sequences of Pseudomonas aeruginosa B3 Strains Isolated from a Cystic Fibrosis Patient Undergoing Antibiotic Chemotherapy

DEFF Research Database (Denmark)

Marvig, Rasmus Lykke; Jochumsen, Nicholas; Johansen, Helle Krogh

2013-01-01

Pseudomonas aeruginosa frequently establishes chronic infections in the airways of patients suffering from cystic fibrosis (CF). Here, we report the draft genome sequences of four P. aeruginosa B3 strains isolated from a chronically infected CF patient undergoing antibiotic chemotherapy.......Pseudomonas aeruginosa frequently establishes chronic infections in the airways of patients suffering from cystic fibrosis (CF). Here, we report the draft genome sequences of four P. aeruginosa B3 strains isolated from a chronically infected CF patient undergoing antibiotic chemotherapy....

Genome Sequence of the Biocontrol Strain Pseudomonas fluorescens F113

Science.gov (United States)

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

Degradation of naphthalene and fluorene by radiolysis using accelerated electrons; Degradacion de naftaleno y fluoreno por radiolisis empleando electrones acelerados

Energy Technology Data Exchange (ETDEWEB)

Flores de Jesus, I

2003-07-01

The volume of the dangerous wastes in global level is causing the poisoning of planet and all of the ecosystems, degrading the life level of millions of humans and causing serious problems in the public health. Since a years ago the volumes of organic effluents generated by the few industry and small populations were so tiny that a natural debugger process in a time and space delimited, acquiring again their natural characteristics and they could be used again. Nowadays these wastes are so numerous and precise in some cases that the capacity of natural purification in the receiving channel is not enough, in addition to the difficulty to treat them in conventional processes, this leads to the decrease in the water's quality making impossible its future use and causing with this a serious ecological problem. This fact has motivated the development of measures that tend to the conservation of the environment and in consequence, the development of debugger technologies with no generation of sub products that often are more dangerous than the originals, due to the previous thing, the treatment by means of radiation of the water is impelled since is a method that allows to degrade or to eliminate in simultaneous form pathogenic microorganisms and organic substances. The radiation by means of electrons beams is a method of advanced treatment who allows to degrade organic compounds, transforming them in compounds with less molecular weight, and in the best of the cases until its oxidation to carbon dioxide and water. In the present thesis the objective is the study of naphthalene and fluorene degradation by means of radiation with electron beams, establishing the operating conditions of the accelerator of Pelletron type. This research is supported by the Instituto Nacional de Investigaciones Nucleares, of a joint way with a series of antecedents in this subject, established in previous research with respect to the treatment of residual waters in a great scale, giving

Degradation of naphthalene and fluorene by radiolysis using accelerated electrons; Degradacion de naftaleno y fluoreno por radiolisis empleando electrones acelerados

Energy Technology Data Exchange (ETDEWEB)

Flores de Jesus, I

2003-07-01

The volume of the dangerous wastes in global level is causing the poisoning of planet and all of the ecosystems, degrading the life level of millions of humans and causing serious problems in the public health. Since a years ago the volumes of organic effluents generated by the few industry and small populations were so tiny that a natural debugger process in a time and space delimited, acquiring again their natural characteristics and they could be used again. Nowadays these wastes are so numerous and precise in some cases that the capacity of natural purification in the receiving channel is not enough, in addition to the difficulty to treat them in conventional processes, this leads to the decrease in the water's quality making impossible its future use and causing with this a serious ecological problem. This fact has motivated the development of measures that tend to the conservation of the environment and in consequence, the development of debugger technologies with no generation of sub products that often are more dangerous than the originals, due to the previous thing, the treatment by means of radiation of the water is impelled since is a method that allows to degrade or to eliminate in simultaneous form pathogenic microorganisms and organic substances. The radiation by means of electrons beams is a method of advanced treatment who allows to degrade organic compounds, transforming them in compounds with less molecular weight, and in the best of the cases until its oxidation to carbon dioxide and water. In the present thesis the objective is the study of naphthalene and fluorene degradation by means of radiation with electron beams, establishing the operating conditions of the accelerator of Pelletron type. This research is supported by the Instituto Nacional de Investigaciones Nucleares, of a joint way with a series of antecedents in this subject, established in previous research with respect to the treatment of residual waters in a great scale, giving

Combining fluorescent Pseudomonas spp. strains to enhance suppression of fusarium wilt of radish

NARCIS (Netherlands)

Boer, Marjan de; Sluis, Ientse van der; Loon, L.C. van; Bakker, P.A.H.M.

1999-01-01

Fusarium wilt diseases, caused by the fungus Fusarium oxysporum, lead to significant yield losses of crops. One strategy to control fusarium wilt is the use of antagonistic, root-colonizing Pseudomonas spp. It has been demonstrated that different strains of these bacteria suppress disease by

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

Science.gov (United States)

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.

Controlled field release of a bioluminescent genetically engineered microorganism for bioremediation process monitoring and control

Energy Technology Data Exchange (ETDEWEB)

Ripp, S.; Nivens, D.E.; Ahn, Y.; Werner, C.; Jarrell, J. IV; Easter, J.P.; Cox, C.D.; Burlage, R.S.; Sayler, G.S.

2000-03-01

Pseudomonas fluorescens HK44 represents the first genetically engineered microorganism approved for field testing in the United States for bioremediation purposes. Strain HK44 harbors an introduced lux gene fused within a naphthalene degradative pathway, thereby allowing this recombinant microbe to bioluminescent as it degrades specific polyaromatic hydrocarbons such as naphthalene. The bioremediation process can therefore be monitored by the detection of light. P. fluorescens HK44 was inoculated into the vadose zone of intermediate-scale, semicontained soil lysimeters contaminated with naphthalene, anthracene, and phenanthrene, and the population dynamics were followed over an approximate 2-year period in order to assess the long-term efficacy of using strain HK44 for monitoring and controlling bioremediation processes. Results showed that P. fluorescens HK44 was capable of surviving initial inoculation into both hydrocarbon contaminated and uncontaminated soils and was recoverable from these soils 660 days post inoculation. It was also demonstrated that strain HK44 was capable of generating bioluminescence in response to soil hydrocarbon bioavailability. Bioluminescence approaching 166,000 counts/s was detected in fiber optic-based biosensor devices responding to volatile polyaromatic hydrocarbons, while a portable photomultiplier module detected bioluminescence at an average of 4300 counts/s directly from soil-borne HK44 cells within localized treatment areas. The utilization of lux-based bioreporter microorganisms therefore promises to be a viable option for in situ determination of environmental contaminant bioavailability and biodegradation process monitoring and control.

Isolation and identification of biosurfactant-producing strains from the genus Pseudomonas aeruginosa and antibacterial effects of biosurfactant production in vitro

Directory of Open Access Journals (Sweden)

Salman Ahmady-Asbchin

2013-01-01

Full Text Available Introduction: Biosurfactants are amphiphilic biological compounds produced extracellularly or as part of the cell membranes by a variety of microorganisms. Because of their use in various industries, they are of a particular importance. The aim of this study was to identify a strain of bacteria of the genus Pseudomonas aeruginosa biosurfactant producers. Materials and methods: In this study, different samples of oil, water and soil contaminated with oil were prepared. Hemolytic activity, emulsification activity and measurement of surface tension were used and selected strains were identified by biochemical tests. The nature and effect of antibacterial biosurfactant was evaluated for strain selection.Results: In this study, eighty eight bacterial strains were isolated. Twenty four strains were isolated from the isolated strains with hemolytic activity. Among which, 14 strains have emulsification activity more than 70% and at last four strains reached surface tension to be less than 40 mN/m. Selected strain based on biochemical tests was recognized as a Pseudomonas aeruginosa. The nature of biosurfactant was determined by TLC, and proved to be of glycolipid kind. Therefore, the produced biosurfactant of the selected strain had antibacterial activity against six bacterial infectious. Sensitive bacteria to the effects of biosurfactant extract of Pseudomonas aeruginosa83, was Staphylococcus aureus and the most resistant bacteria to these extract, was the Proteus mirabilis. The results of MIC, MBC showed that MIC of the extract in concentration of 63 and 125 mg/ml on Escherichia coli, Staphylococcus epidermidis and Staphylococcus aureus respectively. Also, the MBC were extract in concentration of 63 and 125mg/ml on Staphylococcus epidermidis and Staphylococcus aureus respectively.Discussion and conclusion: Pseudomonas aeruginosa had high potential in reducing the surface tension and biosurfactant extracted had high antibacterial effects. Therefore, it

Effect of trichloroethylene on the competitive behavior of toluene-degrading bacteria

NARCIS (Netherlands)

Mars, Astrid E.; Prins, Gjalt T.; Wietzes, Pieter; Koning, Wim de; Janssen, Dick B.

The influence of trichloroethylene (TCE) on a mixed culture of four different toluene-degrading bacterial strains (Pseudomonas putida mt-2, P. putida F1, P. putida GJ31, and Burkholderia cepacia G4) was studied with a fed-batch culture. The strains were competing for toluene, which was added at a

The effect of rhamnolipid biosurfactant produced by Pseudomonas fluorescens on model bacterial strains and isolates from industrial wastewater.

Science.gov (United States)

Vasileva-Tonkova, Evgenia; Sotirova, Anna; Galabova, Danka

2011-02-01

In this study, the effect of rhamnolipid biosurfactant produced by Pseudomonas fluorescens on bacterial strains, laboratory strains, and isolates from industrial wastewater was investigated. It was shown that biosurfactant, depending on the concentration, has a neutral or detrimental effect on the growth and protein release of model Gram (+) strain Bacillus subtilis 168. The growth and protein release of model Gram (-) strain Pseudomonas aeruginosa 1390 was not influenced by the presence of biosurfactant in the medium. Rhamnolipid biosurfactant at the used concentrations supported the growth of some slow growing on hexadecane bacterial isolates, members of the microbial community. Changes in cell surface hydrophobicity and permeability of some Gram (+) and Gram (-) isolates in the presence of rhamnolipid biosurfactant were followed in experiments in vitro. It was found that bacterial cells treated with biosurfactant became more or less hydrophobic than untreated cells depending on individual characteristics and abilities of the strains. For all treated strains, an increase in the amount of released protein was observed with increasing the amount of biosurfactant, probably due to increased cell permeability as a result of changes in the organization of cell surface structures. The results obtained could contribute to clarify the relationships between members of the microbial community as well as suggest the efficiency of surface properties of rhamnolipid biosurfactant from Pseudomonas fluorescens making it potentially applicable in bioremediation of hydrocarbon-polluted environments.

[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].

Science.gov (United States)

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.

Survival of a Rifampicin-Resistant Pseudomonas fluorescens Strain in Nine Mollisols

Directory of Open Access Journals (Sweden)

Tami L. Stubbs

2014-01-01

Full Text Available Pseudomonas fluorescens strain D7 (P.f. D7 is a naturally occurring soil bacterium that shows promise as a biological herbicide to inhibit growth of annual grass weeds, including downy brome (Bromus tectorum L., in crop- and rangelands. Pseudomonas fluorescens strain D7rif (P.f. D7rif is a rifampicin-resistant strain of P.f. D7. One of the greatest obstacles to successful biological weed control is survival of the organism under field conditions. Nine soils in the taxonomic order of Mollisols, collected from downy brome-infested areas of the Western and Central United States, were inoculated with P.f. D7rif and incubated in the laboratory to determine the effects of soil type, soil properties, incubation temperature, and soil water potential on survival of P.f. D7rif over 63 days. Silt loam soils from Lind, Washington, and Moro, Oregon, sustained the highest P.f. D7rif populations, and recovery was the lowest from Pendleton, Oregon soil. Survival and recovery of P.f. D7rif varied with soil type and temperature but not with the two soil water potentials tested. After 63 days, P.f. D7rif was recovered at levels greater than log 5.5 colony forming units (CFU g−1 soil from five of the nine test soils, a level adequate to suppress downy brome under field or range conditions.

Alkaline protease contributes to pyocyanin production in Pseudomonas aeruginosa.

Science.gov (United States)

Iiyama, Kazuhiro; Takahashi, Eigo; Lee, Jae Man; Mon, Hiroaki; Morishita, Mai; Kusakabe, Takahiro; Yasunaga-Aoki, Chisa

2017-04-01

The role of the alkaline protease (AprA) in pyocyanin production in Pseudomonas aeruginosa was investigated. AprA was overproduced when a plasmid carrying the aprA gene was introduced to an aprA-deletion mutant strain, EG03; thus, aprA-complemented EG03 was used as an overproducing strain. The complemented strain produced higher pyocyanin than the mutant strain in all commercially available media evaluated. Particularly, pyocyanin production was higher in the complemented than in the parental strain in brain-heart infusion and tryptic soy broths. These results suggested that protein degradation products by AprA were utilized for pyocyanin production. Protein-rich media were used in subsequent validation studies. Similar results were obtained when the basal medium was supplemented with casein or skim milk as the sole organic nitrogen source. However, gelatin failed to induce abundant pyocyanin production in the complemented strain, despite the presence of protein degradation products by AprA as assessed by SDS-PAGE. Thus, gelatin degradation products may not be suitable for pyocyanin synthesis. In conclusion, AprA could contribute to pyocyanin production in the presence of several proteins or peptides. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Carbazole degradation in the soil microcosm by tropical bacterial strains

Directory of Open Access Journals (Sweden)

Lateef B. Salam

2015-01-01

Full Text Available In a previous study, three bacterial strains isolated from tropical hydrocarbon-contaminated soils and phylogenetically identified as Achromobacter sp. strain SL1, Pseudomonassp. strain SL4 and Microbacterium esteraromaticum strain SL6 displayed angular dioxygenation and mineralization of carbazole in batch cultures. In this study, the ability of these isolates to survive and enhance carbazole degradation in soil were tested in field-moist microcosms. Strain SL4 had the highest survival rate (1.8 x 107 cfu/g after 30 days of incubation in sterilized soil, while there was a decrease in population density in native (unsterilized soil when compared with the initial population. Gas chromatographic analysis after 30 days of incubation showed that in sterilized soil amended with carbazole (100 mg/kg, 66.96, 82.15 and 68.54% were degraded by strains SL1, SL4 and SL6, respectively, with rates of degradation of 0.093, 0.114 and 0.095 mg kg−1 h−1. The combination of the three isolates as inoculum in sterilized soil degraded 87.13% carbazole at a rate of 0.121 mg kg−1 h−1. In native soil amended with carbazole (100 mg/kg, 91.64, 87.29 and 89.13% were degraded by strains SL1, SL4 and SL6 after 30 days of incubation, with rates of degradation of 0.127, 0.121 and 0.124 mg kg−1h−1, respectively. This study successfully established the survivability (> 106 cfu/g detected after 30 days and carbazole-degrading ability of these bacterial strains in soil, and highlights the potential of these isolates as seed for the bioremediation of carbazole-impacted environments.

Genome Sequences of Two Pseudomonas syringae pv. tomato Race 1 Strains, Isolated from Tomato Fields in California

OpenAIRE

Thapa, Shree P.; Coaker, Gitta

2016-01-01

Pseudomonas syringae pv. tomato race 1 strains have evolved to overcome genetic resistance in tomato. Here, we present the draft genome sequences of two race 1 P.?syringae pv. tomato strains, A9 and 407, isolated from diseased tomato plants in California.

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

Science.gov (United States)

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

Degradative capacities and bioaugmentation potential of an anaerobic benzene-degrading bacterium strain DN11

Energy Technology Data Exchange (ETDEWEB)

Yuki Kasai; Yumiko Kodama; Yoh Takahata; Toshihiro Hoaki; Kazuya Watanabe [Marine Biotechnology Institute, Kamaishi (Japan)

2007-09-15

Azoarcus sp. strain DN11 is a denitrifying bacterium capable of benzene degradation under anaerobic conditions. The present study evaluated strain DN11 for its application to bioaugmentation of benzene-contaminated underground aquifers. Strain DN11 could grow on benzene, toluene, m-xylene, and benzoate as the sole carbon and energy sources under nitrate-reducing conditions, although o- and p-xylenes were transformed in the presence of toluene. Phenol was not utilized under anaerobic conditions. Kinetic analysis of anaerobic benzene degradation estimated its apparent affinity and inhibition constants to be 0.82 and 11 {mu}M, respectively. Benzene-contaminated groundwater taken from a former coal-distillation plant site in Aichi, Japan was anaerobically incubated in laboratory bottles and supplemented with either inorganic nutrients (nitrogen, phosphorus, and nitrate) alone, or the nutrients plus strain DN11, showing that benzene was significantly degraded only when DN11 was introduced. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments, and quantitative PCR revealed that DN11 decreased after benzene was degraded. Following the decrease in DN11 16S rRNA gene fragments corresponding to bacteria related to Owenweeksia hongkongensis and Pelotomaculum isophthalicum, appeared as strong bands, suggesting possible metabolic interactions in anaerobic benzene degradation. Results suggest that DN11 is potentially useful for degrading benzene that contaminates underground aquifers at relatively low concentrations. 50 refs., 6 figs., 1 tab.

Occurrence of Ambler Class B Metallo-β-Lactamase Gene in Imipenem-Resistant Pseudomonas Aeruginosa Strains Isolated from Clinical Samples

Directory of Open Access Journals (Sweden)

Zeynab Golshani

2014-02-01

Full Text Available Background: 5TMetallo-β-lactamase (MBLs can hydrolyze a broad spectrum of beta-lactams, including penicillins, cephalosporins, and carbapenems. Genes encoding these enzymes are located on the plasmid that can easily be transferred to other bacteria. The aim of this study was to isolate and identify the Pseudomonas aeruginosa strains encoding VIM1 gene, in clinical samples, using the PCR technique. Materials and Methods: During a 4 month period, 100 strains of Pseudomonas aeruginosa from clinical specimens were collected. Standard tests were performed to identify strains of Pseudomonas aeruginosa. Resistance to antibiotics was examined and then the PCR was used to detect VIM1gene. Results:In this study, the highest rates of resistance to antibiotics, amikacin and cefotaxime was observed (65% and 62%, the lowest resistance to antibiotics piperacillin (48% and imipenem and cefepime with 55% resistance was reported. DDST method was performed for 37 strains for the MBl detection. Among the 37 isolate, 30 strains were MBL-producing with imipenem-EDTA method. Twelve strains (18% were carriers of VIM1 gene using the PCR method. Conclusion: In the present study, the prevalence of strains producing MBL genes in strains of hospitals is a growing trend; correct prescription of medications can prevent the spread of resistant pathogens. It is suggested that molecular methods for rapid detection of resistance genes can be used to prevent the spread of this genes.

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

Science.gov (United States)

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.

Bioremediation of Petroleum hydrocarbon by using Pseudomonas species isolated from Petroleum contaminated soil

OpenAIRE

Vijay Kumar; Simranjeet Singh; Anu Manhas; Joginder Singh; Sourav Singla; Parvinder Kaur; Shivika Data; Pritika Negi; Arjun Kalia

2014-01-01

A newly isolated strain Pseudomonas fluorescens (Accession number KF 279042.1) have potential in diesel degradation and can be recommended for bioremediation of sites that are contaminated with diesel. This bacterium was characterized on the basis of microbiological, biochemical and molecular analysis. Bacterial growth optimization was studied based on carbon source, nitrogen source, pH and temperature. The strain was selected based on its ability to show growth in medium containing diesel. I...

Effect of degradative plasmid CAM-OCT on responses of Pseudomonas bacteria to UV light

International Nuclear Information System (INIS)

McBeth, D.L.

1989-01-01

The effect of plasmid CAM-OCT on responses to UV irradiation was compared in Pseudomonas aeruginosa, in Pseudomonas putida, and in Pseudomonas putida mutants carrying mutations in UV response genes. CAM-OCT substantially increased both survival and mutagenesis in the two species. P. aeruginosa strains without CAM-OCT exhibited much higher UV sensitivity than did P. putida strains. UV-induced mutagenesis of plasmid-free P. putida was easily detected in three different assays (two reversion assays and one forward mutation assay), whereas UV mutagenesis of P. aeruginosa without CAM-OCT was seen only in the forward mutation assay. These results suggest major differences in DNA repair between the two species and highlight the presence of error-prone repair functions on CAM-OCT. A number of P. putida mutants carrying chromosomal mutations affecting either survival or mutagenesis after UV irradiation were isolated, and the effect of CAM-OCT on these mutants was determined. All mutations producing a UV-sensitive phenotype in P. putida were fully suppressed by the plasmid, whereas the plasmid had a more variable effect on mutagenesis mutations, suppressing some and producing no suppression of others. On the basis of the results reported here and results obtained by others with plasmids carrying UV response genes, it appears that CAM-OCT may differ either in regulation or in the number and functions of UV response genes encoded

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

Science.gov (United States)

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...

Characterization of CMR5c and CMR12a, novel fluorescent Pseudomonas strains from the cocoyam rhizosphere with biocontrol activity

NARCIS (Netherlands)

Perneel, M.; Heyrman, J.; Adiobo, A.; Maeyer, de K.; Raaijmakers, J.M.; Vos, de P.; Höfte, M.

2007-01-01

Aim: To screen for novel antagonistic Pseudomonas strains producing both phenazines and biosurfactants that are as effective as Pseudomonas aeruginosa PNA1 in the biocontrol of cocoyam root rot caused by Pythium myriotylum. Material and Results: Forty pseudomonads were isolated from the rhizosphere

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

Science.gov (United States)

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 .

Naphthalene degradation in seawater by UV irradiation: The effects of fluence rate, salinity, temperature and initial concentration

International Nuclear Information System (INIS)

Jing, Liang; Chen, Bing; Zhang, Baiyu; Zheng, Jisi; Liu, Bo

2014-01-01

Highlights: • The removal of naphthalene follows first order kinetics in seawater. • Irradiance and temperature are the most influential factors. • An increase in irradiance can linearly promote photodegradation. • High salinity suppresses the photodegradation of naphthalene. - Abstract: A large amount of oil pollution at sea is produced by the operational discharge of oily wastewater. The removal of polycyclic aromatic hydrocarbons (PAHs) from such sources using UV irradiation has become attractive, yet the photolysis mechanism in seawater has remained unclear. This study examines the photodegradation kinetics of naphthalene in natural seawater through a full factorial design of experiments (DOE). The effects of fluence rate, salinity, temperature and initial concentration are investigated. Results show that fluence rate, temperature and the interaction between temperature and initial concentration are the most influential factors. An increase in fluence rate can linearly promote the photodegradation process. Salinity increasingly impedes the removal of naphthalene because of the existence of free-radical scavengers and photon competitors. The results will help understand the photolysis mechanism of PAHs and develop more effective methods for treating oily seawater generated from offshore industries

Molecular characterization of genes of Pseudomonas sp. strain HR199 involved in bioconversion of vanillin to protocatechuate.

Science.gov (United States)

Priefert, H; Rabenhorst, J; Steinbüchel, A

1997-01-01

The gene loci vdh, vanA, and vanB, which are involved in the bioconversion of vanillin to protocatechuate by Pseudomonas sp. strain HR199 (DSM 7063), were identified as the structural genes of a novel vanillin dehydrogenase (vdh) and the two subunits of a vanillate demethylase (vanA and vanB), respectively. These genes were localized on an EcoRI fragment (E230), which was cloned from a Pseudomonas sp. strain HR199 genomic library in the cosmid pVK100. The vdh gene was identified on a subfragment (HE35) of E230, and the vanA and vanB genes were localized on a different subfragment (H110) of E230. The nucleotide sequences of fragment HE35 and part of fragment H110 were determined, revealing open reading frames of 1062, 951, and 1446 bp, representing vanA, vanB, and vdh, respectively. The vdh gene was organized in one operon together with a fourth open reading frame (ORF2), of 735 bp, which was located upstream of vdh. The deduced amino acid sequences of vanA and vanB exhibited 78.8 and 62.1% amino acid identity, respectively, to the corresponding gene products from Pseudomonas sp. strain ATCC 19151 (F. Brunel and J. Davison, J. Bacteriol. 170:4924-4930, 1988). The deduced amino acid sequence of the vdh gene exhibited up to 35.3% amino acid identity to aldehyde dehydrogenases from different sources. The deduced amino acid sequence of ORF2 exhibited up to 28.4% amino acid identity to those of enoyl coenzyme A hydratases. Escherichia coli strains harboring fragment E230 cloned in pBluescript SK- converted vanillin to protocatechuate via vanillate, indicating the functional expression of vdh, vanA, and vanB in E. coli. High expression of vdh in E. coli was achieved with HE35 cloned in pBluescript SK-. The resulting recombinant strains converted vanillin to vanillate at a rate of up to 0.3 micromol per min per ml of culture. Transfer of vanA, vanB, and vdh to Alcaligenes eutrophus and to different Pseudomonas strains, which were unable to utilize vanillin or vanillate as

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

Science.gov (United States)

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.

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

NARCIS (Netherlands)

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

2004-01-01

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

Comparative genomic and functional analyses: unearthing the diversity and specificity of nematicidal factors in Pseudomonas putida strain 1A00316

Science.gov (United States)

Guo, Jing; Jing, Xueping; Peng, Wen-Lei; Nie, Qiyu; Zhai, Yile; Shao, Zongze; Zheng, Longyu; Cai, Minmin; Li, Guangyu; Zuo, Huaiyu; Zhang, Zhitao; Wang, Rui-Ru; Huang, Dian; Cheng, Wanli; Yu, Ziniu; Chen, Ling-Ling; Zhang, Jibin

2016-01-01

We isolated Pseudomonas putida (P. putida) strain 1A00316 from Antarctica. This bacterium has a high efficiency against Meloidogyne incognita (M. incognita) in vitro and under greenhouse conditions. The complete genome of P. putida 1A00316 was sequenced using PacBio single molecule real-time (SMRT) technology. A comparative genomic analysis of 16 Pseudomonas strains revealed that although P. putida 1A00316 belonged to P. putida, it was phenotypically more similar to nematicidal Pseudomonas fluorescens (P. fluorescens) strains. We characterized the diversity and specificity of nematicidal factors in P. putida 1A00316 with comparative genomics and functional analysis, and found that P. putida 1A00316 has diverse nematicidal factors including protein alkaline metalloproteinase AprA and two secondary metabolites, hydrogen cyanide and cyclo-(l-isoleucyl-l-proline). We show for the first time that cyclo-(l-isoleucyl-l-proline) exhibit nematicidal activity in P. putida. Interestingly, our study had not detected common nematicidal factors such as 2,4-diacetylphloroglucinol (2,4-DAPG) and pyrrolnitrin in P. putida 1A00316. The results of the present study reveal the diversity and specificity of nematicidal factors in P. putida strain 1A00316. PMID:27384076

Antifungal activity of plant essential oils and selected Pseudomonas strains against Phomopsis theicola

Directory of Open Access Journals (Sweden)

Starović Mira

2017-01-01

Full Text Available Development of natural plant protection products as an alternative to synthetic fungicides is of significant importance regarding the environment. This study was carried out with an objective to investigate in vitro antifungal activities of several essential oils extracted from oregano, basil, myrtle and Turkish pickling herb, and the plant growth-promoting rhizobacteria in the genus Pseudomonas, against the phytopathogenic fungus Phomopsis theicola. Microdilution methods were used to determine the minimum inhibitory concentrations (MIC of selected antimicrobial essential oils (EOs. All EOs exhibited significant levels of antifungal activity against the tested fungal isolates. The oregano EO was found the most potent one (MIC - 5.5 µg/mL, followed by basil (MIC - 75.0µg/mL, myrtle (MIC - 775 µg/mL and Turkish pickling herb (MIC - 7750 µg/mL. Inhibition of Ph. theicola mycelial growth was observed for all tested Pseudomonas spp. strains. K113 and L1 strains were highly effective and achieved more than 60% of fungal growth inhibition using the overnight culture and more than 57% inhibition by applying cell-free supernatants of both strains. A future field trial with K113 and L1 cultures and cell-free supernatants, containing extracellular metabolites toward Ph. theicola, will estimate their effectiveness and applicability as an alternative to chemical protection of apple trees.

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

Science.gov (United States)

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.

Metalaxyl Degradation by Mucorales Strains Gongronella sp. and Rhizopus oryzae

Directory of Open Access Journals (Sweden)

Maria Rosário Martins

2017-12-01

Full Text Available 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.

Diversity of small RNAs expressed in Pseudomonas species

DEFF Research Database (Denmark)

Gomez-Lozano, Mara; Marvig, Rasmus Lykke; Molina-Santiago, Carlos

2015-01-01

RNA sequencing (RNA-seq) has revealed several hundreds of previously undetected small RNAs (sRNAs) in all bacterial species investigated, including strains of Pseudomonas aeruginosa, Pseudomonas putida and Pseudomonas syringae. Nonetheless, only little is known about the extent of conservation...... of expressed sRNAs across strains and species. In this study, we have used RNA-seq to identify sRNAs in P.putidaDOT-T1E and Pseudomonas extremaustralis 14-3b. This is the first strain of P.extremaustralis and the second strain of P.putida to have their transcriptomes analysed for sRNAs, and we identify...... the presence of around 150 novel sRNAs in each strain. Furthermore, we provide a comparison based on sequence conservation of all the sRNAs detected by RNA-seq in the Pseudomonas species investigated so far. Our results show that the extent of sRNA conservation across different species is very limited...

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

Energy Technology Data Exchange (ETDEWEB)

Khan, Fazlurrahman; Pandey, Janmejay; Vikram, Surendra; Pal, Deepika; Cameotra, Swaranjit Singh, E-mail: ssc@imtech.res.in

2013-06-15

Highlights: • This study reports isolation of a novel bacterium capable of mineralizing 4-nitroaniline (4-NA). • This bacterium has been identified as Rhodococcus sp. strain FK48. • Strain FK48 degrades 4-NA via a novel aerobic degradation pathway that involves 4-AP and 1,2,4-BT. • Subsequent degradation proceeds via ring fission and formation of maleylacetate. • This is the first report showing elucidation of catabolic pathway for microbial degradation 4-NA. -- Abstract: 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 NO{sub 2} substituent) and deamination (release of NH{sub 2} 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.

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

International Nuclear Information System (INIS)

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

2013-01-01

Highlights: • This study reports isolation of a novel bacterium capable of mineralizing 4-nitroaniline (4-NA). • This bacterium has been identified as Rhodococcus sp. strain FK48. • Strain FK48 degrades 4-NA via a novel aerobic degradation pathway that involves 4-AP and 1,2,4-BT. • Subsequent degradation proceeds via ring fission and formation of maleylacetate. • This is the first report showing elucidation of catabolic pathway for microbial degradation 4-NA. -- Abstract: 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 NO 2 substituent) and deamination (release of NH 2 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

Cometabolic degradation kinetics of TCE and phenol by Pseudomonas putida.

Science.gov (United States)

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 (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.

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

Science.gov (United States)

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

Two draft genome sequences of Pseudomonas jessenii strains isolated from a copper contaminated site in Denmark

DEFF Research Database (Denmark)

Qin, Yanan; Wang, Dan; Brandt, Kristian Koefoed

2016-01-01

Pseudomonas jessenii C2 and Pseudomonas jessenii H16 were isolated from low-Cu and high-Cu industrially contaminated soil, respectively. P. jessenii H16 displayed significant resistance to copper when compared to P. jessenii C2. Here we describe genome sequences and interesting features of these ......Pseudomonas jessenii C2 and Pseudomonas jessenii H16 were isolated from low-Cu and high-Cu industrially contaminated soil, respectively. P. jessenii H16 displayed significant resistance to copper when compared to P. jessenii C2. Here we describe genome sequences and interesting features...... of these two strains. The genome of P. jessenii C2 comprised 6,420,113 bp, with 5814 protein-coding genes and 67 RNA genes. P. jessenii H16 comprised 6,807,788 bp, with 5995 protein-coding genes and 70 RNA genes. Of special interest was a specific adaptation to this harsh copper-contaminated environment as P....... jessenii H16 contained a novel putative copper resistance genomic island (GI) of around 50,000 bp....

The Genome of the Toluene-Degrading Pseudomonas veronii Strain 1YdBTEX2 and Its Differential Gene Expression in Contaminated Sand.

Directory of Open Access Journals (Sweden)

Marian Morales

Full Text Available The natural restoration of soils polluted by aromatic hydrocarbons such as benzene, toluene, ethylbenzene and m- and p-xylene (BTEX may be accelerated by inoculation of specific biodegraders (bioaugmentation. Bioaugmentation mainly involves introducing bacteria that deploy their metabolic properties and adaptation potential to survive and propagate in the contaminated environment by degrading the pollutant. In order to better understand the adaptive response of cells during a transition to contaminated material, we analyzed here the genome and short-term (1 h changes in genome-wide gene expression of the BTEX-degrading bacterium Pseudomonas veronii 1YdBTEX2 in non-sterile soil and liquid medium, both in presence or absence of toluene. We obtained a gapless genome sequence of P. veronii 1YdBTEX2 covering three individual replicons with a total size of 8 Mb, two of which are largely unrelated to current known bacterial replicons. One-hour exposure to toluene, both in soil and liquid, triggered massive transcription (up to 208-fold induction of multiple gene clusters, such as toluene degradation pathway(s, chemotaxis and toluene efflux pumps. This clearly underlines their key role in the adaptive response to toluene. In comparison to liquid medium, cells in soil drastically changed expression of genes involved in membrane functioning (e.g., lipid composition, lipid metabolism, cell fatty acid synthesis, osmotic stress response (e.g., polyamine or trehalose synthesis, uptake of potassium and putrescine metabolism, highlighting the immediate response mechanisms of P. veronii 1YdBTEX2 for successful establishment in polluted soil.

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

Science.gov (United States)

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.

Simultaneous biodegradation of bifenthrin and chlorpyrifos by Pseudomonas sp. CB2.

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

Dionisi, H.M.; Chewning, C.S.; Morgan, K.H.; Menn, F.M.; Easter, J.P; Sayler, G.S. [University of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology

2004-07-01

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-{mu}l 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) X 10{sup 3} to (2.9 {+-} 0.3) X 10{sup 5} copies of nagAc-like dioxygenase genes per mug of DNA extracted from sediment samples. These values corresponded to (1.2 {+-} 0.6) X 10{sup 5} to (5.4 {+-} 0.4) X 10{sup 7} 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 = 0.89) and per gram of dry weight sediment = 0.77). These results provide evidence of the ecological significance of organisms carrying nagAc-like genes in the biodegradation of naphthalene.

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

Science.gov (United States)

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.

Salicylic acid degradation from aqueous solutions using Pseudomonas fluorescens HK44: parameters studies and application tools Degradação de ácido salicílico presente em soluções sintéticas utilizando Pseudomonas fluorescens HK44

Directory of Open Access Journals (Sweden)

Tatyane R. Silva

2007-03-01

Full Text Available The optimal conditions for salicylic acid biodegradation by Pseudomonas fluorescens HK44 were determined in this study with the intention to create a microbial sensor. Kinetic experiments permitted a definition of 60 and 30min the time needed to achieve the maximum degradation of salicylic acid presented in a medium with and without yeast extract, respectively. The degradation in medium without yeast extract and the quantification by spectrophotometry 230 nm were selected to be used in further tests. The use of preactivated cells or on the exponential growth phase showed better salicylic acid degradation percentages when compared to nonactivated cells or on the stationary growth state. Finally, the best cellular concentration used on the salicylic acid degradation was 0,1 g.L-1. Strain HK44 shows to be capable of degrade salicylic acid presented in simple aqueous systems, making this strain a promising tool for the application on a luminescent microbial sensor.Com a intenção de criar um sensor microbiano, as condições ótimas para a biodegradação de ácido salicílico por Pseudomonas fluorescens HK44 foram determinadas neste estudo. Os experimentos cinéticos permitiram a definição dos tempos de 60 e 30 minutos como necessários para atingir a máxima degradação de ácido salicílico presente em meio com ou sem extrato de lêvedo, respectivamente. A degradação no meio sem extrato de lêvedo e a quantificação através de espectrofotometria 230 nm foram selecionadas para serem utilizadas em testes posteriores. O uso de células pré-ativadas ou na fase exponencial de crescimento apresentou melhores porcentagens de degradação de ácido salicílico quando comparadas a células não-ativadas ou no estado estacionário de crescimento. Além disso, a melhor concentração celular utilizada nessa degradação foi 0,1 g.L¹. A cepa HK44 parece ser capaz de degradar o ácido salicílico presente em sistemas aquosos simples, tornando este

LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA

International Nuclear Information System (INIS)

Molloy, Daniel P.

2001-01-01

These experiments indicated that bacterial strain CL0145A of Pseudomonas fluorescens is equally lethal to the 2 zebra mussel species present in North America, Dreissena polymorpha and Dreissena bugensis. Thus, this bacterial strain should be equally effective at killing zebra mussels in power plant pipes, irrespective of which species is present

LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA

Energy Technology Data Exchange (ETDEWEB)

Daniel P. Molloy

2001-10-28

These experiments indicated that bacterial strain CL0145A of Pseudomonas fluorescens is equally lethal to the 2 zebra mussel species present in North America, Dreissena polymorpha and Dreissena bugensis. Thus, this bacterial strain should be equally effective at killing zebra mussels in power plant pipes, irrespective of which species is present.

Microbial Degradation of Polycyclic Aromatic Hydrocarbons and Characterization of Bacteria

Science.gov (United States)

Tikilili, P. V.; Chirwa, E. M. N.

2010-01-01

Biodegradation of polycyclic aromatic hydrocarbons was studied. Naphthalene was used as a model compound to represent these compounds. Low initial concentrations of naphthalene in a range of 30-60 mg/L were completely degraded after incubation for 15 hrs by consortia from a landfill soil while consortia from minewater took more that 29 hrs to reach complete degradation.

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

Science.gov (United States)

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.

Application of green fluorescent protein for monitoring phenol-degrading strains

Directory of Open Access Journals (Sweden)

Ana Milena Valderrama F.

2001-07-01

Full Text Available Several methods have been developed for detecting microorganisms in environmental samples. Some systems for incorporating reporter genes, such as lux or the green fluorescent protein (GFP gene, have been developed recently This study describes gfp gene marking of a phenol degrading strain, its evaluation and monitoring in a bioreactor containing refinery sour water. Tagged strains were obtained having the same physiological and metabolic characteristics as the parent strain. Fluorescent expression was kept stable with no selection for more than 50 consecutive generations and tagged strains were recovered from the bioreactor after forty-five days of phenol-degradation treatment.

Genomotyping of Pseudomonas putida strains using P. putida KT2440-based high-density DNA microarrays: Implications for transcriptomics studies

NARCIS (Netherlands)

Ballerstedt, H.; Volkers, R.J.M.; Mars, A.E.; Hallsworth, J.E.; Santos, V.A.M.D.; Puchalka, J.; Duuren, J. van; Eggink, G.; Timmis, K.N.; Bont, J.A.M. de; Wery, J.

2007-01-01

Pseudomonas putida KT2440 is the only fully sequenced P. putida strain. Thus, for transcriptomics and proteomics studies with other P. putida strains, the P. putida KT2440 genomic database serves as standard reference. The utility of KT2440 whole-genome, high-density oligonucleotide microarrays for

Accumulation of a Polyhydroxyalkanoate Containing Primarily 3-Hydroxydecanoate from Simple Carbohydrate Substrates by Pseudomonas sp. Strain NCIMB 40135

OpenAIRE

Haywood, Geoffrey W.; Anderson, Alistair J.; Ewing, David F.; Dawes, Edwin A.

1990-01-01

A number of Pseudomonas species have been identified which accumulate a polyhydroxyalkanoate containing mainly 3-hydroxydecanoate monomers from sodium gluconate as the sole carbon source. One of these, Pseudomonas sp. strain NCIMB 40135, was further investigated and shown to accumulate such a polyhydroxyalkanoate from a wide range of carbon sources (C2 to C6); however, when supplied with octanoic acid it produced a polyhydroxyalkanoate containing mainly 3-hydroxyoctanoate monomers. Polymer sy...

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Assessment of Bacterial Degradation of Aromatic Hydrocarbons in the Environment by Analysis of Stable Carbon Isotope Fractionation

International Nuclear Information System (INIS)

Meckenstock, Rainer U.; Morasch, Barbara; Kaestner, Matthias; Vieth, Andrea; Richnow, Hans Hermann

2002-01-01

13 C/ 12 C stable carbon isotope fractionation was used to assess biodegradation in contaminated aquifers with toluene as a model compound. Different strains of anaerobic bacteria (Thauera aromatica, Geobacter metallireducens, and the sulfate-reducing strain TRM1) showed consistent 13 C/ 12 C carbon isotope fractionation with fractionation factors between αC = 1.0017 and 1.0018. In contrast, three cultures of aerobic organisms, using different mono- and dioxygenase enzyme systems to initiate toluene degradation, showed variable isotope fractionation factors of αC = 1.0027 (Pseudomonasputida strain mt-2), αC = 1.0011 (Ralstonia picketii), andαC = 1.0004 (Pseudomonas putida strain F1). The great variability of isotope fractionation between different aerobic bacterial strains suggests that interpretation of isotope data in oxic habitats can only be qualitative. A soil column was run as a model system for contaminated aquifers with toluene as the carbon source and sulfate as the electron acceptor and samples were taken at different ports along the column. Microbial toluene degradation was calculated based on the 13 C/ 12 C isotope fractionation factors of the batch culture experiments together with the observed 13 C/ 12 C isotope shifts of the residual toluene fractions. The calculated percentage of biodegradation, B, correlated well with the decreasing toluene concentrations at the sampling ports and indicated the increasing extent of biodegradation along the column. The theoretical toluene concentrations as calculated based on the isotope values matched the measured concentrations at the different sampling ports indicating that the Rayleigh equation can be used to calculate biodegradation in quasi closed systems based on measured isotope shifts. A similar attempt was performed to assess toluene degradation in a contaminated, anoxic aquifer. A transect of groundwater wells was monitored along the main direction of the groundwater flow and revealed decreasing

Pseudomonas fluvialis sp. nov., a novel member of the genus Pseudomonas isolated from the river Ganges, India.

Science.gov (United States)

Sudan, Sarabjeet Kour; Pal, Deepika; Bisht, Bhawana; Kumar, Narender; Chaudhry, Vasvi; Patil, Prabhu; Sahni, Girish; Mayilraj, Shanmugam; Krishnamurthi, Srinivasan

2018-01-01

A bacterial strain, designated ASS-1 T , was isolated and identified from a sediment sample of the river Ganges, Allahabad, India. The strain was Gram-stain-negative, formed straw-yellow pigmented colonies, was strictly aerobic, motile with a single polar flagellum, and positive for oxidase and catalase. The major fatty acids were C16 : 1ω7c/ 16 : 1 C16 : 1ω6c, C18 : 1ω7c and C16 : 0. Sequence analysis based on the 16S rRNA gene revealed that strain ASS-1 T showed high similarity to Pseudomonas guguanensis CC-G9A T (98.2 %), Pseudomonas alcaligenes ATCC 14909 T (98.2 %), Pseudomonas oleovorans DSM 1045 T (98.1 %), Pseudomonas indolxydans IPL-1 T (98.1 %) and Pseudomonas toyotomiensis HT-3 T (98.0 %). Analysis of its rpoB and rpoD housekeeping genes confirmed its phylogenetic affiliation and showed identities lower than 93 % with respect to the closest relatives. Phylogenetic analysis based on the 16S rRNA, rpoB, rpoD genes and the whole genome assigned it to the genus Pseudomonas. The results of digital DNA-DNA hybridization based on the genome-to-genome distance calculator and average nucleotide identity revealed low genome relatedness to its close phylogenetic neighbours (below the recommended thresholds of 70 and 95 %, respectively, for species delineation). Strain ASS-1 T also differed from the related strains by some phenotypic characteristics, i.e. growth at pH 5.0 and 42 °C, starch and casein hydrolysis, and citrate utilization. Therefore, based on data obtained from phenotypic and genotypic analysis, it is evident that strain ASS-1 T should be regarded as a novel species within the genus Pseudomonas, for which the name Pseudomonasfluvialis sp. nov. is proposed. The type strain is ASS-1 T (=KCTC 52437 T =CCM 8778 T ).

methoxyethanol by a new bacterium isolate Pseudomonas sp. Strain

African Journals Online (AJOL)

Michael Horsfall

A 2-methoxyethanol degrading bacterium was isolated from anaerobic sludge of a municipal sewage from ... Stoichiometrically, the strain utilized one mole of oxygen per one mole of 2-methoxyethanol instead of ... physiological and biochemical characterization of the .... observed with acetate and the intact resting cells.

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

Directory of Open Access Journals (Sweden)

Emmanouil A Trantas

2015-08-01

Full Text Available 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 commercially significant 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 a type III secretion system and of known type III effectors 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.

Screening of Gibberellic Acid Production by Pseudomonas SPP

International Nuclear Information System (INIS)

Khine Zar Wynn Myint; Khin Mya Lwin; Myo Myint

2010-12-01

The microbial gibberellic acid (GA3) production of Pseudomonas spp., was studied and qualitatively indentified by UV spectrophotometer. 20 strains of Pseudomonas spp., were isolated and screened the gibberellic acid productivily in King's B medium. Among them, only four strains can produce microbial gibberellic acid. The Rf values and colour appearance under UV were the same as authentic gibberellic acid. Moreover, the gibberellic acid producer strains were identified as Pseudomonas spp., by cultural, biochemical and drug sensitivity pattern.

The mutant strain of ZHJ6 degrading organophosphorous pesticide by 60Co-γ irradiation

International Nuclear Information System (INIS)

Zhao Renbang; Chi Jian; He Yi

2013-01-01

The strain of Penicillium oxalicum ZHJ6 that can degrade methamidophos was employed to obtain the mutant stain which has higher degradation rate than original strain by 60 Co-γ irradiation. Results showed that the Penicillium oxalicum ZHJ6 was sensitive to 60 Co-γ irradiation, and was easy to be killed by 60 Co-γ irradiation. Under the absorbed dose of 2.1 kGy, the survival rate of the strain was 0.04%. Two strains of A17 and A18 were obtained from the irradiated strains after first- and second- screening and the degradation rate of methamidophos of A17 and A18 strains were 10% higher than that of A0 strain (original stain). Moreover, the abilities to degrade folimat, phoxim and glyphosate were improved. Through 5 generations, the variation coefficient in degradation rate of methamidophos in the 6th day was 1.2%, showing that the new strains had hereditary stability. (authors)

Detection of Quorum Sensing Activity in the Multidrug-Resistant Clinical Isolate Pseudomonas aeruginosa Strain GB11

OpenAIRE

Huey Jia Cheng; Robson Ee; Yuet Meng Cheong; Wen-Si Tan; Wai-Fong Yin; Kok-Gan Chan

2014-01-01

A multidrug-resistant clinical bacteria strain GB11 was isolated from a wound swab on the leg of a patient. Identity of stain GB11 as Pseudomonas aeruginosa was validated by using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Detection of the production of signaling molecules, N-acylhomoserine lactones (AHLs), was conducted using three different bacterial biosensors. A total of four different AHLs were found to be produced by strain GB11, namely...

RESEARCH IN SENSITIVITY TO ANTIBIOTICS, ANTISEPTICS IN PSEUDOMONAS AERUGINOSA STRAINS ISOLATED FROM PATIENTS WITH INFECTIOUS COMPLICATIONS

OpenAIRE

O. A. Nazarchuk; D. V. Paliy; N. I. Osadchuk

2017-01-01

Background. Infections caused by Pseudomonas are one of the topical issues of medicine. Objective. The aim of the research was to study sensityvity to antibiotics, antiseptics of P. aeruginosa clinical strains that cause infectious complications in patients with burns. Methods. Microbiological study of biological material, received from 435 patients with burns of the 3rd-4th stages (2011-2015 years). In early terms of burn disease 127 clinical strains of P. aeruginosa were isolated fr...

Removal effectiveness and mechanisms of naphthalene and heavy metals from artificially contaminated soil by iron chelate-activated persulfate

International Nuclear Information System (INIS)

Yan, Dickson Y.S.; Lo, Irene M.C.

2013-01-01

The effectiveness and mechanisms of naphthalene and metal removal from artificially contaminated soil by FeEDTA/FeEDDS-activated persulfate were investigated through batch experiments. Using FeEDTA-activated persulfate, higher naphthalene removal from the soil at 7 h was achieved (89%), compared with FeEDDS-activated persulfate (75%). The removal was mainly via the dissolution of naphthalene partitioned on mineral surfaces, followed by activated persulfate oxidation. Although EDDS is advantageous over EDTA in terms of biodegradability, it is not preferable for iron chelate-activated persulfate oxidation since persulfate was consumed to oxidize EDDS, resulting in persulfate inadequacy for naphthalene oxidation. Besides, 55 and 40% of naphthalene were removed by FeEDTA and FeEDDS alone, respectively. Particularly, 21 and 9% of naphthalene were degraded in the presence of FeEDTA and FeEDDS alone, respectively, which caused by electrons transfer among dissolved organic matter, Fe 2+ /Fe 3+ and naphthalene. Over 35, 36 and 45% of Cu, Pb and Zn were removed using FeEDTA/FeEDDS-activated persulfate. -- Highlights: ► FeEDTA/FeEDDS-activated persulfate oxidation removed PAH and heavy metal from soil. ► More naphthalene was removed by FeEDTA-activated persulfate compared to FeEDDS. ► Persulfate was consumed to oxidize EDDS in FeEDDS-activated persulfate oxidation. ► Metals can be extracted from soil by free EDTA/EDDS dissociated from FeEDTA/FeEDDS. ► Naphthalene oxidation can be induced by e − transfer among Fe 2+ , DOM and naphthalene. -- This study focuses on the potencies and mechanisms of naphthalene and metal removal from contaminated soil by FeEDTA/FeEDDS-activated persulfate

Naphthalene distributions and human exposure in Southern California

Science.gov (United States)

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

Enhancement of the potential to utilize octopine in the nonfluorescent Pseudomonas sp. strain 92

International Nuclear Information System (INIS)

Gill, S.S.; Boivin, R.; Dion, P.

1991-01-01

The nonfluorescent Pseudomonas sp. strain 92 requires the presence of a supplementary carbon source for growth on octopine, whereas the spontaneous mutant RB100 has acquired the capacity to utilize this opine as the sole carbon and nitrogen source. Insertional mutagenesis of RB100 with transposon Tn5 generated mutants which were unable to grow on octopine and others which grew slowly on this substrate. Both types of mutants yielded revertants that had regained the ability to utilize octopine. Some of the revertants had lost the transposon, whereas in others the transposon was retained but with rearrangements of the insertion site. Genes of octopine catabolism from strain 92 were cloned on a cosmid vector to generate pK3. The clone pK3 conferred the ability to utilize octopine as the sole carbon and nitrogen source on the host Pseudomonas putida KT2440. Although they conferred an equivalent growth phenotype, the mutant genes carried by RB100 and the cloned genes on pK3 differed in their regulation. Utilization of [ 14 C]octopine was inducible by octopine in RB100 and was constitutive in KT2440(pK3)

Microbial flora analysis for the degradation of beta-cypermethrin.

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Nina Yusrina Muhamad Yunos

2014-06-01

Full Text Available 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.

RESEARCH IN SENSITIVITY TO ANTIBIOTICS, ANTISEPTICS IN PSEUDOMONAS AERUGINOSA STRAINS ISOLATED FROM PATIENTS WITH INFECTIOUS COMPLICATIONS

Directory of Open Access Journals (Sweden)

O. A. Nazarchuk

2017-07-01

Full Text Available Background. Infections caused by Pseudomonas are one of the topical issues of medicine. Objective. The aim of the research was to study sensityvity to antibiotics, antiseptics of P. aeruginosa clinical strains that cause infectious complications in patients with burns. Methods. Microbiological study of biological material, received from 435 patients with burns of the 3rd-4th stages (2011-2015 years. In early terms of burn disease 127 clinical strains of P. aeruginosa were isolated from patients. Standard methods were used to identify clinical isolates of P. aeruginosa by their morphological, tinctirial, culture and biochemical properties. The research of antimicrobial action of antiseptics, antibiotics against Pseudomonas were carried out by means of standard methods according to the Directive of the Ministry of Health of Ukraine (No. 167 from 05.04.2007 р. and guidelines of National Committee of Clinical and Laboratory Study (NCCLS, 2002. Results. It was established that P. aeruginosa caused infectious complications in 23.9% of patients among other pathogens. Clinical isolates of P. aeruginosa were found to be low sensitive to amoxicillin/clavulanate (30.76%, ceftazidime (25.92%, cefoperazonum/sulbactam (46.15%, aztreonam (51.85%, tobramycin (38.46%, amicacin (70.34%, doxiciclini (26.92%, fluoroquinolones (59.26%. The analitical progistic criteria of decrease of sensitivity to ceftazidime, cefepim, meropenem and gatifloxacin were found in P. aeruginosa. This pathogen was determined to be sensitive to decasan ®, antimicrobial composition of decamethoxine ®, iodine pvidone. Conclusions. Clinical strains of Pseudomonas aeruginosa, being highly resistant to antibiotics, are also very sensitive to antiseptics decasan ®, antimicrobial of decamethoxine®, povidone iodine.

Quantitative proteomic analysis of ibuprofen-degrading Patulibacter sp. strain I11

DEFF Research Database (Denmark)

Almeida, Barbara; Kjeldal, Henrik; Lolas, Ihab Bishara Yousef

2013-01-01

was identified and quantified by gel based shotgun-proteomics. In total 251 unique proteins were quantitated using this approach. Biological process and pathway analysis indicated a number of proteins that were up-regulated in response to active degradation of ibuprofen, some of them are known to be involved...... in the degradation of aromatic compounds. Data analysis revealed that several of these proteins are likely involved in ibuprofen degradation by Patulibacter sp. strain I11.......Ibuprofen is the third most consumed pharmaceutical drug in the world. Several isolates have been shown to degrade ibuprofen, but very little is known about the biochemistry of this process. This study investigates the degradation of ibuprofen by Patulibacter sp. strain I11 by quantitative...

Pseudomonas syringae evades host Immunity by degrading flagellin monomers with alkaline protease AprA

OpenAIRE

Pel, M.J.C.; Van Dijken, A.J.H.; Bardoel, B.W.; Seidl, M.F; Van der Ent, S.; Van Strijp, J.A.G.

2014-01-01

Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant athogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantl...

Uranium uptake by immobilized cells of Pseudomonas strain EPS 5028

International Nuclear Information System (INIS)

Pons, M.P.; Fuste, M.C.

1993-01-01

Polyacrylamide-gel-immobilized cells of Pseudomonas strain EPS 5028 were effective in the removal of uranium (U) from synthetic effluents. Metal accumulation was performed in an open system in columns filled with immobilized cells that were challenged with continuous flows containing U. Possible variable of the system were studied. Uranium uptake by the immobilized cells of this microorganism was affected by pH but not by temperature or flow rate. In addition, U binding could be interpreted in terms of the Freundlich adsorption isotherm indicating single-layer adsorption. The feasibility of reusing the immobilized cells was suggested after the recovery of U with a solution of 0.1 M sodium carbonate. (orig.)

Study on the Novel Dicyanate Ester Resin Containing Naphthalene Unit

Institute of Scientific and Technical Information of China (English)

Hong Qiang YAN; Hong Yun PENG; Li JI; Guo Rong QI

2004-01-01

The novel dicyanate ester resin containing naphthalene unit (DNCY) was synthesized, and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analysis (EA).The thermal properties of DNCY resin was studied by thermal degradation analysis at a heating rate of 10 (C /min-1 in N2 and air. The DNCY resin exhibited better thermal and thermal-oxidative stability than bisphenol A dicyanate (BACY) resin.

Biphenyl Modulates the Expression and Function of Respiratory Oxidases in the Polychlorinated-Biphenyls Degrader Pseudomonas pseudoalcaligenes KF707

Directory of Open Access Journals (Sweden)

Federica Sandri

2017-06-01

Full Text Available Pseudomonas pseudoalcaligenes KF707 is a soil bacterium which is known for its capacity to aerobically degrade harmful organic compounds such as polychlorinated biphenyls (PCBs using biphenyl as co-metabolite. Here we provide the first genetic and functional analysis of the KF707 respiratory terminal oxidases in cells grown with two different carbon sources: glucose and biphenyl. We identified five terminal oxidases in KF707: two c(caa3 type oxidases (Caa3 and Ccaa3, two cbb3 type oxidases (Cbb31 and Cbb32, and one bd type cyanide-insensitive quinol oxidase (CIO. While the activity and expression of both Cbb31 and Cbb32 oxidases was prevalent in glucose grown cells as compared to the other oxidases, the activity and expression of the Caa3 oxidase increased considerably only when biphenyl was used as carbon source in contrast to the Cbb32 oxidase which was repressed. Further, the respiratory activity and expression of CIO was up-regulated in a Cbb31 deletion strain as compared to W.T. whereas the CIO up-regulation was not present in Cbb32 and C(caa3 deletion mutants. These results, together, reveal that both function and expression of cbb3 and caa3 type oxidases in KF707 are modulated by biphenyl which is the co-metabolite needed for the activation of the PCBs-degradation pathway.

Accumulation of metabolites during bacterial degradation of PAH-mixtures

Energy Technology Data Exchange (ETDEWEB)

Vila, J.; Lopez, Z.; Bauza, J.I. [Universitat de Barcelona (Spain). Department de Microbiologia; Minguillon, C. [Parc Cientific de Barcelona (ES). Institut de Recerca de Barcelona (IRB-PCB); Grifoll, M.

2003-07-01

In a previous work we identified a number of metabolites accumulated during growth in pyrene by Mycobacterium sp. AP1, and proposed a metabolic pathway for pyrene utilization. In order to confirm and complete this pathway we have isolated and identified the pyrene-degrading strains Mycobacterium sp. PGP2, CP1 and CP2. During growth on pyrene, strains AP1, PGP2, CP1 and CP2 accumulated 4,5-cis-pyrene-dihydrodiol, 4,5-phenanthrene dicarboxylic acid, 4-phenanthrene carboxylic acid, 3,4-dihydroxy-3-hydrophenanthrene-4-carboxylic acid, phthalic acid, and 6,6'-dihydroxy-2,2'-biphenyl dicarboxylic acid. Strains AP1, PGP2, CP1 and CP2 also grew on fluoranthene accumulating acenaphthenone, naphthalene-1,8-dicarboxylic acid, 9-fluorenone-1-carboxylic acid, Z-9-carboxymethylenefluorene-1-carboxylic acid and benzene-1,2,3-tricarboxylic acid. Similar metabolites were produced during growth onf fluoranthene by the Gram-positive strains CFt2 and CFt6, isolated by their capability of using this PAH as a sole source of carbon and energy. These fluoranthene-degrading strains also accumulated cis-1,9a-dihydroxy-1-hydrofluorene-9-one-8-carboxylic acid. In addition to pyrene and fluoranthene, all pyrene-degrading utilized phenanthrene as a sole source of carbon and energy, while the fluoranthene-degrading strains were unable to utilize pyrene or phenanthrene. Mycobacterium sp. AP1 acted on a wide range of PAHs, accumulating aromatic dicarboxylic acids, hydroxyacids, and ketones resulting from dioxygenation and ortho-cleavage, dioxygenation and meta-cleavage, and monooxygenation reactions. In cultures of strains AP1 and CP1 with a defined PAH-mixture only 20% removal of the parent compounds was observed. Analysis of acidic extracts showed the accumulation of the anticipated aromatic acids, suggesting that accumulation of acidic compounds could prevent further degradation of the mixture. Those results led us to isolation of strains DF11 and OH3, able to grow on the selected

Pseudomonas tarimensis sp. nov., an endophytic bacteria isolated from Populus euphratica.

Science.gov (United States)

Anwar, Nusratgul; Rozahon, Manziram; Zayadan, Bolatkhan; Mamtimin, Hormathan; Abdurahman, Mehfuzem; Kurban, Marygul; Abdurusul, Mihribangul; Mamtimin, Tursunay; Abdukerim, Muhtar; Rahman, Erkin

2017-11-01

An endophytic bacterium, MA-69 T , was isolated from the storage liquid in the stems of Populuseuphratica trees at the ancient Ugan River in Xinjiang, PR China. Strain MA-69 T was found to be short rod-shaped, Gram-stain-negative, non-spore-forming, aerobic and motile by means of a monopolar flagellum. According to phylogenetic analysis based on 16S rRNA gene sequences, strain MA-69 T was assigned to the genus Pseudomonas with highest 16S rRNA gene sequence similarity of 97.5 % to Pseudomonas azotifigens JCM 12708 T , followed by Pseudomonas matsuisoli JCM 30078 T (97.5 %), Pseudomonas balearica DSM 6083 T (97.1 %), Azotobacter salinestris ATCC 49674 T (96.1 %) and Pseudomonas indica DSM 14015 T (95.9 %). Analysis of strain MA-69 T based on the three housekeeping genes, rpoB, rpoD and gyrB, further confirmed the isolate to be distinctly delineated from species of the genus Pseudomonas. The DNA G+C content of strain MA-69 T was 64.1 mol%. DNA-DNA hybridization with Pseudomonas azotifigens JCM 12708 T , Pseudomonas matsuisoli JCM 30078 T and Pseudomonas balearica DSM 6083 T revealed 62.9, 60.1 and 49.0 % relatedness, respectively. The major fatty acids in strain MA-69 T were summed feature 3 (25.7 %), summed feature 8 (24.0 %), C19 : 0cyclo ω8c (19.9 %), C16 : 0 (14.6 %) and C12 : 0 (6.3 %). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Q-9 was the major quinone in strain MA-69 T . Based on phenotypic, chemotaxonomic and phylogenetic properties, strain MA-69 T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas tarimensis sp. nov. is proposed. The type strain is MA-69 T (=CCTCC AB 2013065 T =KCTC 42447 T ).

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

Science.gov (United States)

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

Genome Sequence of Pseudomonas aeruginosa Strain DK1-NH57388A, a Stable Mucoid Cystic Fibrosis Isolate

DEFF Research Database (Denmark)

Norman, Anders; Ciofu, Oana; Amador Hierro, Cristina Isabel

2016-01-01

Pseudomonas aeruginosa is an important opportunistic pathogen associated with chronic pulmonary infections and mortality in cystic fibrosis (CF) patients. Here, we present the complete genome sequence of stable mucoid P. aeruginosa strain DK1-NH57388A, a CF isolate which has previously been used...

Bioaugmentation of aerobic sludge granules with a plasmid donor strain for enhanced degradation of 2,4-dichlorophenoxyacetic acid

International Nuclear Information System (INIS)

Quan Xiangchun; Tang Hua; Xiong Weicong; Yang Zhifeng

2010-01-01

Aerobic sludge granules pre-grown on glucose were bioaugmented with a plasmid pJP4 carrying strain Pseudomonas putida SM1443 in a fed-batch microcosm system and a lab-scale sequencing batch reactor (SBR) to enhance their degradation capacity to 2,4-dichlorophenoxyacetic acid (2,4-D). The fed-batch test results showed that the bioaugmented aerobic granule system gained 2,4-D degradation ability faster and maintained a more stable microbial community than the control in the presence of 2,4-D. 2,4-D at the initial concentration of about 160 mg/L was nearly completely removed by the bioaugmented granule system within 62 h, while the control system only removed 26% within 66 h. In the bioaugmented SBR which had been operated for 90 days, the seeded aerobic granules pre-grown on glucose successfully turned into 2,4-D degrading granules through bioaugmentation and stepwise increase of 2,4-D concentration from 8 to 385 mg/L. The granules showed a compact structure and good settling ability with the mean diameter of about 450 μm. The degradation kinetics of 2,4-D by the aerobic granules can be described with the Haldane kinetics model with V max = 31.1 mg 2,4-D/gVSS h, K i = 597.9 mg/L and K s = 257.3 mg/L, respectively. This study shows that plasmid mediated bioaugmentation is a feasible strategy to cultivate aerobic granules degrading recalcitrant pollutants.

Effects of ambroxol on biofilm adhesion and viability of Pseudomonas aeruginosa quorum sensing defective strain

Directory of Open Access Journals (Sweden)

Qi LU

2013-07-01

Full Text Available Objective　To investigate the effects of ambroxol on the biofilm viability and pristine adhesion of Pseudomonas aeruginosa wild (PAO1 and quorum sensing defective strain (QS, gene deletion of ∆lasI and ∆rhlI. Methods　The biofilm was treated by different concentrations (0, 1.875, 3.75mg/ml of ambroxol. The number of colony was measured with agar plate, multifunction fluorometer was used to measure the fluorescence intensity of PAO1 and QS strains at the bottom of 96-well plate. The adhesion ratio (% was calculated to determine the effects of ambroxol on bacterial biofilm adhesion. Results　Ambroxol treatment reduced the survival rate of the mutant strains compared to that of wild strain, even though the QS strain had increased the adhesion in the presence of ambroxol compared to that of wild strain (P<0.05. Conclusion　Ambroxol has a property of significantly antagonizing quorum-sensing system, suggesting that it might be of importance in treatment against chronic Pseudomonasaeruginosainfections.

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

Science.gov (United States)

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

2017-04-13

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

Draft Genome Sequence of an Invasive Multidrug-Resistant Strain, Pseudomonas aeruginosa BK1, Isolated from a Keratitis Patient

KAUST Repository

Jeganathan, Lakshmi Priya; Prakash, Logambiga; Neelamegam, Sivakumar; Antony, Aju; Alqarawi, Sami; Prajna, Lalitha; Devarajan, Bharanidharan; Mohankumar, Vidyarani

2014-01-01

Pseudomonas aeruginosa infections are difficult to treat due to the presence of a multitude of virulence factors and antibiotic resistance. Here, we report the draft genome sequence of P. aeruginosa BK1, an invasive and multidrug-resistant strain

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

Science.gov (United States)

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

Science.gov (United States)

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

Assessment of strains of Pseudomonas syringae pv. tomato from Tanzania for resistance to copper and streptomycin

DEFF Research Database (Denmark)

Shenge, K.C.; Wydra, K.; Mabagala, M.B.

2008-01-01

Fifty-six strains of Pseudomonas syringae pv. tomato (P.s. pv. tomato) were collected from tomato-producing areas in Tanzania and assessed for resistance to copper and antibiotics. The collection was done from three tomato-producing regions (Morogoro, Arusha and Iringa), representing three...... different ecological conditions in the country. After isolation and identification, the P. s. pv. tomato strains were grown on King's medium B (KB) amended with 20% copper sulphate (w/v). The strains were also assessed for resistance to antibiotics. Results indicated that there was widespread resistance...... strains of the pathogen were moderately resistant to copper sulphate, such that 54.0% of them were able to grow on the KB medium amended with 20% (w/v) of the copper compound....

Mechanism for Clastogenic Activity of Naphthalene

Energy Technology Data Exchange (ETDEWEB)

Buchholz, Bruce A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-09-29

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.

Mechanism for Clastogenic Activity of Naphthalene

Energy Technology Data Exchange (ETDEWEB)

Buchholz, Bruce A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

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.

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

DEFF Research Database (Denmark)

Ellegaard-Jensen, Lea; Aamand, Jens; Kragelund, Birthe Brandt

2013-01-01

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...

Detection of catabolic genes in indigenous microbial consortia isolated from a diesel-contaminated soil

International Nuclear Information System (INIS)

Milcic-Terzic, J.; Saval, S.; Lopez-Vidal, Y.; Vrvic, M.M.

2001-01-01

Bioremediation is often used for in situ remediation of petroleum-contaminated sites. The primary focus of this study was on understanding the indigenous microbial community which can survive in contaminated environment and is responsible for the degradation. Diesel, toluene and naphthalene-degrading microbial consortia were isolated from diesel-contaminated soil by growing on selective hydrocarbon substrates. The presence and frequency of the catabolic genes responsible for aromatic hydrocarbon biodegradation (xylE, ndoB) within the isolated consortia were screened using polymerase chain reaction PCR and DNA-DNA colony hybridization. The diesel DNA-extract possessed both the xylE catabolic gene for toluene, and the nah catabolic gene for polynuclear aromatic hydrocarbon degradation. The toluene DNA-extract possessed only the xylE catabolic gene, while the naphthalene DNA-extract only the ndoB gene. Restriction enzyme analysis with HaeIII indicated similar restriction patterns for the xylE gene fragment between toluene DNA-extract and a type strain, Pseudomonas putida ATCC 23973. A substantial proportion (74%) of the colonies from the diesel-consortium possessed the xylE gene, and the ndoB gene (78%), while a minority (29%) of the toluene-consortium harbored the xylE gene. 59% of the colonies from the naphthalene-consortium had the ndoB gene, and did not have the xylE gene. These results indicate that the microbial population has been naturally enriched in organisms carrying genes for aromatic hydrocarbon degradation and that significant aromatic biodegradative potential exists at the site. Characterization of the population genotype constitutes a molecular diagnosis which permits the determination of the catabolic potential of the site to degrade the contaminant present. (author)

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

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 and 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.

Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

Science.gov (United States)

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.

2-[3-(Naphthalen-2-ylphenyl]naphthaleneCAS 103068–17–3.

Directory of Open Access Journals (Sweden)

Mark L. Wolfenden

2013-02-01

Full Text Available The title compound, C26H18, consists of a benzene ring with meta-substituted 2-naphthalene substituents, which are essentially planar [r.m.s. deviations = 0.022 (1 and 0.003 (1 Å]. The conformation is syn, with equivalent torsion angles about the benzene–naphthalene bonds of −36.04 (13 and +34.14 (13°. The molecule has quasi-Cs molecular symmetry.

Identification and characterization of an N-acylhomoserine lactone-dependent quorum-sensing system in Pseudomonas putida strain IsoF

DEFF Research Database (Denmark)

Steidle, A.; Allesen-Holm, M.; Riedel, K.

2002-01-01

Recent reports have shown that several strains of Pseudomonas putida produce N-acylhomoserine lactones (AHLs). These signal molecules enable bacteria to coordinately express certain phenotypic traits in a density-dependent manner in a process referred to as quorum sensing. In this study we have...

Heterogeneity of heat-resistant proteases from milk Pseudomonas species.

Science.gov (United States)

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.

Directory of Open Access Journals (Sweden)

Lázaro Molina

Full Text Available 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.

Purification and Characterization of a Novel β-Cypermethrin-Degrading Aminopeptidase from Pseudomonas aeruginosa GF31.

Science.gov (United States)

Tang, Ai-Xing; Liu, Hu; Liu, You-Yan; Li, Qing-Yun; Qing, Yi-Ming

2017-11-01

In this study, a novel β-cypermethrin-degrading enzyme was isolated and purified by 32.8 fold from the extracellular cell-free filtrate of Pseudomonas aeruginosa GF31with the protein recovery of 26.6%. The molecular mass of the enzyme was determined to be 53 kDa. The optimum temperature for the activity was surprisingly 60 °C, and moreover, the purified enzyme showed a good pH stability, maintaining over 85% of its initial activity in the pH 5.0-9.0 range. Most of the common metal ions exhibited little influence on the activity except for Hg 2+ , Ag + , and Cu 2+ . After the complete gene sequence of the degrading enzyme was obtained by subcloning, sequence analyses as well as enzymatic properties demonstrated that the islolated enzyme should be an aminopeptidase. This is the first reported aminopeptidase for pyrethroid hydrolase, providing new potential enzyme resources for the degradation of this type of pesticide.

Assessment of Bacterial Degradation of Aromatic Hydrocarbons in the Environment by Analysis of Stable Carbon Isotope Fractionation

Energy Technology Data Exchange (ETDEWEB)

Meckenstock, Rainer U. [Eberhard-Karls University of Tuebingen, Center for Applied Geoscience (Germany)], E-mail: rainer.meckenstock@uni-tuebingen.de; Morasch, Barbara [University of Konstanz, Faculty of Biology (Germany); Kaestner, Matthias; Vieth, Andrea; Richnow, Hans Hermann [Center for Environmental Research, Department of Remediation Research (Germany)

2002-05-15

{sup 13}C/{sup 12}C stable carbon isotope fractionation was used to assess biodegradation in contaminated aquifers with toluene as a model compound. Different strains of anaerobic bacteria (Thauera aromatica, Geobacter metallireducens, and the sulfate-reducing strain TRM1) showed consistent {sup 13}C/{sup 12}C carbon isotope fractionation with fractionation factors between {alpha}C = 1.0017 and 1.0018. In contrast, three cultures of aerobic organisms, using different mono- and dioxygenase enzyme systems to initiate toluene degradation, showed variable isotope fractionation factors of {alpha}C = 1.0027 (Pseudomonasputida strain mt-2), {alpha}C = 1.0011 (Ralstonia picketii), and{alpha}C = 1.0004 (Pseudomonas putida strain F1). The great variability of isotope fractionation between different aerobic bacterial strains suggests that interpretation of isotope data in oxic habitats can only be qualitative. A soil column was run as a model system for contaminated aquifers with toluene as the carbon source and sulfate as the electron acceptor and samples were taken at different ports along the column. Microbial toluene degradation was calculated based on the {sup 13}C/{sup 12}C isotope fractionation factors of the batch culture experiments together with the observed {sup 13}C/{sup 12}C isotope shifts of the residual toluene fractions. The calculated percentage of biodegradation, B, correlated well with the decreasing toluene concentrations at the sampling ports and indicated the increasing extent of biodegradation along the column. The theoretical toluene concentrations as calculated based on the isotope values matched the measured concentrations at the different sampling ports indicating that the Rayleigh equation can be used to calculate biodegradation in quasi closed systems based on measured isotope shifts. A similar attempt was performed to assess toluene degradation in a contaminated, anoxic aquifer. A transect of groundwater wells was monitored along the main

Bioreporter pseudomonas fluorescens HK44 immobilized in a silica matrix

Directory of Open Access Journals (Sweden)

Trogl J.

2003-01-01

Full Text Available The bioluminescent bioreporter Pseudomonas fluorescens HK44, the whole cell bacterial biosensor that responds to naphthalene and its metabolites via the production of visible light, was immobilized into a silica matrix by the sol-gel technique. The bioluminescence intensities were measured in the maximum of the bioluminescence band at X = 500 nm. The immobilized cells (>105 cells per g silica matrix produced light after induction by salicylate (cone. > 10 g/l, naphthalene and aminobenzoic acid. The bioluminescence intensities induced by 2,3-dihydroxynaphthalene 3-hydroxybenzoic acid and 4-hydroxybenzoic acid were comparable to a negative control. The cells in the silica layers on glass slides produced light in response to the presence of an inductor at least 8 months after immobilization, and >50 induction cycles. The results showed that these test slides could be used as assays for the multiple determination of water pollution.

Establishment of pseudomonas putida strains for sensitive detection of heavy metals in effluents

International Nuclear Information System (INIS)

Genthe, B.

1987-09-01

The objective of this study was to isolate a mutant of Pseudomonas putida that is more sensitive to heavy metal toxicants in water than the wild type. P. putida was the organism chosen in this study as it occurs naturally in unpolluted waters, is nonpathogenic, aerobic and because it is commonly applied in bacterial toxicity assays due to its sensitivity to toxicants. Three methods of mutagenesis were employed, which included N-methyl-N'-nitro-N-nitrosoguanidine (NG) ; ultraviolet light and transposon-mediated mutagenesis in order to generate as wide a range of mutants as possible. Four mutants, which were more sensitive to mercury, copper, lead, zinc, cadmium and silver were isolated using the NG method of mutagenesis. These mutants were designated strains 53, 56, 60 and 61 and were characterized as P. putida strains on the basis of Gram staining, biochemical reactions and immunological properties. The sensitivity of the mutants to a variety of industrial effluents was compared to that of the parent strain using a bacterial growth test. Using industrial effluents, one of the mutants, namely strain 56 was found to be more sensitive than the parent strain on 71.4% of the tests. Strains 60 and 61 were also both more sensitive than the parent strain on 42.9% of the occasions using industrial effluents. The uptake rates of radioactive mercury were measured for the parent strain of P. putida and the mutants that were found to be more sensitive to mercury

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Science.gov (United States)

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.

Novel Pathway of Salicylate Degradation by Streptomyces sp. Strain WA46

OpenAIRE

Ishiyama, Daisuke; Vujaklija, Dusica; Davies, Julian

2004-01-01

A novel salicylate-degrading Streptomyces sp., strain WA46, was identified by UV fluorescence on solid minimal medium containing salicylate; trace amounts of gentisate were detected by high-pressure liquid chromatography when strain WA46 was grown with salicylate. PCR amplification of WA46 DNA with degenerate primers for gentisate 1,2-dioxygenase (GDO) genes produced an amplicon of the expected size. Sequential PCR with nested GDO primers was then used to identify a salicylate degradation gen...

Combined use of alkane-degrading and plant growth-promoting bacteria enhanced phytoremediation of diesel contaminated soil.

Science.gov (United States)

Tara, Nain; Afzal, Muhammad; Ansari, Tariq M; Tahseen, Razia; Iqbal, Samina; Khan, Qaiser M

2014-01-01

Inoculation of plants with pollutant-degrading and plant growth-promoting microorganisms is a simple strategy to enhance phytoremediation activity. The objective of this study was to determine the effect of inoculation of different bacterial strains, possessing alkane-degradation and 1-amino-cyclopropane-1 -carboxylic acid (ACC) deaminase activity, on plant growth and phytoremediation activity. Carpet grass (Axonopus affinis) was planted in soil spiked with diesel (1% w/w) for 90 days and inoculated with different bacterial strains, Pseudomonas sp. ITRH25, Pantoea sp. BTRH79 and Burkholderia sp. PsJN, individually and in combination. Generally, bacterial application increased total numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere ofcarpet grass, plant biomass production, hydrocarbon degradation and reduced genotoxicity. Bacterial strains possessing different beneficial traits affect plant growth and phytoremediation activity in different ways. Maximum bacterial population, plant biomass production and hydrocarbon degradation were achieved when carpet grass was inoculated with a consortium of three strains. Enhanced plant biomass production and hydrocarbon degradation were associated with increased numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere of carpet grass. The present study revealed that the combined use of different bacterial strains, exhibiting different beneficial traits, is a highly effective strategy to improve plant growth and phytoremediation activity.

Draft Genome Sequence of an Invasive Multidrug-Resistant Strain, Pseudomonas aeruginosa BK1, Isolated from a Keratitis Patient

KAUST Repository

Jeganathan, Lakshmi Priya

2014-03-27

Pseudomonas aeruginosa infections are difficult to treat due to the presence of a multitude of virulence factors and antibiotic resistance. Here, we report the draft genome sequence of P. aeruginosa BK1, an invasive and multidrug-resistant strain, isolated from a bacterial keratitis patient in southern India.

Synthesis and photophysical characterizations of thermal-stable naphthalene benzimidazoles.

Science.gov (United States)

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

Microbial analyses of cement and grouting additives

International Nuclear Information System (INIS)

Hallbeck, L.; Jaegevall, S.; Paeaejaervi, A.; Rabe, L.; Edlund, J.; Eriksson, S.

2012-01-01

During sampling in the ONKALO tunnel in 2006, heavy growth of a slimy material was observed in connection with grouting. It was suggested to be microbial growth on organic additives leaching from the grout. Two sampling campaigns resulted in the isolation of several aerobic bacterial strains. Some of these strains were used in biodegradation studies of three solid cement powders, eight liquid grout additives, and six plastic drainage materials. Degradation was also studied using ONKALO groundwaters as inoculums. The isolated strains were most closely related to hydrocarbon-degrading microorganisms. The biodegradation of seven of the products was tested using microorganisms isolated from the ONKALO slime in 2006; none of these strains could degrade the tested products. When ONKALO drillhole groundwaters were used as inoculums in the degradation studies, it was demonstrated that Structuro 111X, Mighty 150, and Super-Parmix supported growth of the groundwater microorganisms. Structuro 111X is a polycarboxylate condensate while Mighty 150 and Super-Parmix are condensates with formaldehyde and naphthalene. Some of the isolated microorganisms belonged to the genus Pseudomonas, many strains of which can degrade organic molecules. None of the plastic drainage materials supported growth during the degradation studies. Microorganisms were present in two of the liquid products when delivered, GroutAid and Super-Parmix. The potential of the organic compounds in grout additives to be degraded by microorganisms, increasing the risk of biofilm formation and complexing compound production, must be considered. Microbial growth will also increase the possibility of hydrogen sulphide formation. (orig.)

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

Science.gov (United States)

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.).

Draft Genome Sequence of the Plant Growth–Promoting Pseudomonas punonensis Strain D1-6 Isolated from the Desert Plant Erodium hirtum in Jordan

KAUST Repository

Lafi, Feras Fawzi

2017-01-13

Pseudomonas punonensis strain D1-6 was isolated from roots of the desert plant Erodium hirtum, near the Dead Sea in Jordan. The genome of strain D1-6 reveals several key plant growth-promoting and herbicide-resistance genes, indicating a possible specialized role for this endophyte.

Draft Genome Sequence of the Plant Growth–Promoting Pseudomonas punonensis Strain D1-6 Isolated from the Desert Plant Erodium hirtum in Jordan

KAUST Repository

Lafi, Feras Fawzi; AL Bladi, Maha Lafi Saleh; Salem, Nida M.; Al-Banna, Luma; Alam, Intikhab; Bajic, Vladimir B.; Hirt, Heribert; Saad, Maged

2017-01-01

Pseudomonas punonensis strain D1-6 was isolated from roots of the desert plant Erodium hirtum, near the Dead Sea in Jordan. The genome of strain D1-6 reveals several key plant growth-promoting and herbicide-resistance genes, indicating a possible specialized role for this endophyte.

PFGE and antibiotic susceptibility phenotype analysis of Pseudomonas aeruginosa strain chronically infecting Cystic Fibrosis patients

Directory of Open Access Journals (Sweden)

Giovanna Pulcrano

2008-09-01

Full Text Available Pseudomonas aeruginosa is the leading cause of chronic lung infection and following pulmonary worsening of cystic fibrosis patients. To verify whether bacterial modifications regarding motility, mucoidy, and serum susceptibility proceeded from an adaptation to chronic infection or a replacement with a new strain, sequential P. aeruginosa isolates of known phenotype collected from 5 cystic fibrosis patients were typed by pulsed-field gel electophoresis (PFGE. Antimicrobial susceptibility testing of all isolates was performed by the disc diffusion method. PFGE typing demonstrated that strains dissimilar in colony morphotype and of different antibiotic susceptibility patterns could be of the same genotype. Some patients were colonized with a rather constant P. aeruginosa flora, with strains of different phenotypes but of one genotype. Instead, some patients may be colonized by more than one genotype. Secretion of mucoid exopolysaccharide and acquisition of a new antibiotic susceptibility phenotype in these strain appear to evolve during chronic colonization in cystic fibrosis patients from specific adaptation to infection rather than from acquisition of new bacterial strains.

Chromosomal insertion of the entire Escherichia coli lactose operon, into two strains of Pseudomonas, using a modified mini-Tn5 delivery system

DEFF Research Database (Denmark)

Hansen, L. H.; Sørensen, S. J.; Jensen, Lars Bogø

1997-01-01

A 12-kb PstI fragment including the entire E. coli lactose operon (lacIPOZYA) was inserted in one copy into the chromosome of Pseudomonas putida, Pseudomonas fluorescens and an E. coli strain with lac(-) phenotype. This was made possible by improvements of an already existing mini-Tn5 transposon...... flanked by NotI sites needed in the mini-Tn5 delivery system; (b) the generation of E. coli nonlysogenic strains expressing the pi protein thus being capable of maintaining and delivering R6K-based mini-Tn5 vectors to other E. coli strains; (c) the successful insertion of the E. coli lactose operon...... into the P. fluorescens chromosome giving P. fluorescens the ability to grow on lactose; (d) evidence from Southern blotting that contradicts the assumption that the mini-Tn5 delivery system always creates one-copy inserts. These improvements allow insertion of large DNA fragments encoding highly expressed...

Strain induced irreversible critical current degradation in highly dense Bi-2212 round wire

CERN Document Server

Bjoerstad, R; Rikel, M.O.; Ballarino, A; Bottura, L; Jiang, J; Matras, M; Sugano, M; Hudspeth, J; Di Michiel, M

2015-01-01

The strain induced critical current degradation of overpressure processed straight Bi 2212/Ag wires has been studied at 77 K in self-field. For the first time superconducting properties, lattice distortions, composite wire stress and strain have been measured simultaneously in a high energy synchrotron beamline. A permanent Ic degradation of 5% occurs when the wire strain exceeds 0.60%. At a wire strain of about 0.65% a drastic n value and Ic reduction occur, and the composite stress and the Bi-2212 lattice parameter reach a plateau, indicating Bi-2212 filament fracturing. The XRD measurements show that Bi-2212 exhibits linear elastic behaviour up to the irreversible strain limit.

Genome Sequence of Pseudomonas aeruginosa Strain DK1-NH57388A, a Stable Mucoid Cystic Fibrosis Isolate

DEFF Research Database (Denmark)

Norman, Anders; Ciofu, Oana; Amador Hierro, Cristina Isabel

2016-01-01

Pseudomonas aeruginosa is an important opportunistic pathogen associated with chronic pulmonary infections and mortality in cystic fibrosis (CF) patients. Here, we present the complete genome sequence of stable mucoid P. aeruginosa strain DK1-NH57388A, a CF isolate which has previously been used ...

Decolorization and degradation of daunomycin by bjerkandera adusta R59 strain

Energy Technology Data Exchange (ETDEWEB)

Cho, N.S.; Belearz, A.; Ginalska, G.; Kornillowicz, K.; Cho, H.Y.; Ohga, S. [Kyushu University, Fukuoka (Japan)

2009-02-15

The ability of Bjerkandera adusta R59 strain to degrade anthraquinonic antibiotic (daunomycin) points on its possible aptitudes for decomposing of other anthraquinonic derivatives, e.g. lignocellulose subunits or metabolically related lipids, present in wood. This study was performed to investigate the possibility of B. adusta, R59 to synthesize enzymes participating in decay of wood compounds (including lignin, celluloses, hemicelluloses and lipids). Geotrichum-like strain, anamorphic stadium of B. adusta, white-rot. fungus, was isolated from soil. It was found to completely decolorize and degrade 10% daunomycin post-production effluent during 10 days of incubation at 26{sup o}C. R59 strain produces only small activities of lignolytic enzymes when grown on wheat straw or beech sawdust-containing media but in the presence of humic acids derived from brown coal synthesizes significant activities of laccase and lipase. This phenomenon was coupled with entering the idiophase by this fungus and appearance of aerial mycelium. The ability of B. adusta R59 strain to degrade humic acids from brown coal could be useful in constructing of new generation of biologically active filters for purification of humic acids-contaminated comestible waters.

Draft Genome Sequence of the Phosphate-Solubilizing Bacterium Pseudomonas argentinensis Strain SA190 Isolated from the Desert Plant Indigofera argentea

KAUST Repository

Lafi, Feras Fawzi; Alam, Intikhab; Geurts, Rene; Bisseling, Ton; Bajic, Vladimir B.; Hirt, Heribert; Saad, Maged

2016-01-01

Pseudomonas argentinensis strain SA190 is a plant endophytic-inhabiting bacterium that was isolated from root nodules of the desert plant Indigofera argentea collected from the Jizan region of Saudi Arabia. Here, we report the genome sequence of SA

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

Science.gov (United States)

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.

Effect of Eu(III) on the degradation of malic acid by Pseudomonas fluorescens

International Nuclear Information System (INIS)

Nankawa, T.; Ozaki, T.; Ohnuki, T.; Suzuki, Y.; Francis, A.J.

2005-01-01

Full text of publication follows: The transuranic elements, such as Am(III) and Cm(III), are highly toxic because they emit high-energy α particles and have long half-lives. To estimate their long-term environmental behavior, we need to elucidate degradation of actinide-organic complexes by microorganisms. We studied the biodegradation of Eu(III)-malic acid complexes by Pseudomonas fluorescens. Malic acid is ubiquitous in the environment and is one of the microbial metabolites that is part of the tri-carboxylic acid (TCA) cycle. Europium(III) is a good analogue for Am(III) and Cm(III). To investigate the effect of Eu(III) on the degradation of malic acid by P. fluorescens, we compared the degradation behavior of Eu(III)-malic acid complexes to that of Fe(III) and Al(III)-malic acid complexes. In the medium containing 1 mM malic acid and 0-0.5 mM Fe(III), malic acid was degraded completely. In the medium containing 1 mM malic acid and 0.05-0.5 mM Al(III), malic acid was degraded until the concentration of malic acid became equal to that of Al(III), indicating that Al(III)-malic acid complex with 1: 1 molar ratio was recalcitrant to biodegradation. In the medium containing 1 mM malic acid and 0.05-0.5 mM Eu(III), degradation of malic acid was not observed. The effect of metals on degradation of malic acid was in the order of Fe(III) < Al(III) < Eu(III). The stability constants of 1:1 Fe(III)-, Al(III)-, and Eu(III)-malic acid complexes are 7.1, 4.6, and 4.9, respectively. These results indicate that degradability of malic acid does not depend on the stability constants of metal-malic acid complexes. We found that 10 mM malic acid was degraded in the presence of 0.05 and 0.1 mM Eu(III) but 1 mM malic acid was not degraded in the presence of 0.05 and 0.1 mM Eu(III). The degradation rate of malic acid increased with a decreasing ratio of Eu(III) to malic acid. (authors)

Enhanced biodegradation of naphthalene in MGP aquifer microcosms

International Nuclear Information System (INIS)

Durant, N.D.; Jonkers, C.A.A.; Wilson, L.P.; Bouwer, E.J.

1995-01-01

Subsurface sediments collected from a former manufactured-gas-plant (MGP) site contain bacteria capable of mineralizing significant amounts of 14 C-naphthalene in aerobic (8.5 mg/L O 2 ) sediment-water microcosms incubated at 10 C. The extent to which electron-acceptor (O 2 and NO 3 - ) and nutrient (NO 3 - and PO 4 3- ) amendments enhanced naphthalene mineralization in these sediments varied considerably. Oxygen-amended conditions (21 mg/L O 2 ) resulted in the greatest rate and extent of biodegradation for most sediments. Data suggested, however, that some MGP-site sediments prefer mixed NO 3 - /O 2 electron-acceptor conditions for naphthalene biodegradation. Significant denitrification was observed in the nitrate-amended sediments exhibiting naphthalene mineralization. In most cases, PO 4 3- complexed with the sediments either had no effect or inhibited naphthalene mineralization. Sediments unable to mineralize naphthalene over the 6-week incubation period were characterized by low pH ( 4 2- (>500 mg/L) conditions

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

Science.gov (United States)

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.

Pseudomonas floridensis sp. nov., a bacterial pathogen isolated from tomato.

Science.gov (United States)

Timilsina, Sujan; Minsavage, Gerald V; Preston, James; Newberry, Eric A; Paret, Matthews L; Goss, Erica M; Jones, Jeffrey B; Vallad, Gary E

2018-01-01

An unusual fluorescent pseudomonad was isolated from tomato exhibiting leaf spot symptoms similar to bacterial speck. Strains were fluorescent, oxidase- and arginine-dihydrolase-negative, elicited a hypersensitive reaction on tobacco and produced a soft rot on potato slices. However, the strains produced an unusual yellow, mucoid growth on media containing 5 % sucrose that is not typical of levan. Based on multilocus sequence analysis using 16S rRNA, gap1, gltA, gyrB and rpoD, these strains formed a distinct phylogenetic group in the genus Pseudomonas and were most closely related to Pseudomonas viridiflava within the Pseudomonassyringae complex. Whole-genome comparisons, using average nucleotide identity based on blast, of representative strain GEV388 T and publicly available genomes representing the genus Pseudomonas revealed phylogroup 7 P. viridiflava strain UASW0038 and P. viridiflava type strain ICMP 2848 T as the closest relatives with 86.59 and 86.56 % nucleotide identity, respectively. In silico DNA-DNA hybridization using the genome-to-genome distance calculation method estimated 31.1 % DNA relatedness between GEV388 T and P. viridiflava ATCC 13223 T , strongly suggesting the strains are representatives of different species. These results together with Biolog GEN III tests, fatty acid methyl ester profiles and phylogenetic analysis using 16S rRNA and multiple housekeeping gene sequences demonstrated that this group represents a novel species member of the genus Pseudomonas. The name Pseudomonas floridensis sp. nov. is proposed with GEV388 T (=LMG 30013 T =ATCC TSD-90 T ) as the type strain.

Roles of horizontal gene transfer and gene integration in evolution of 1,3-dichloropropene- and 1,2-dibromoethane-degradative pathways

NARCIS (Netherlands)

Poelarends, GJ; Kulakov, LA; Larkin, MJ; van Hylckama Vlieg, Johan E.T.; Janssen, DB

The haloalkane-degrading bacteria Rhodococcus rhodochrous NCIMB13064, Pseudomonas pavonaceae 170, and Mycobacterium sp. strain GP1 share a highly conserved haloalkane dehalogenase gene (dhaA). Here, we describe the extent of the conserved dhaA segments in these three phylogenetically distinct

Degradation of organic pollutants by methane grown microbial consortia.

Science.gov (United States)

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).

Large-scale bioreactor production of the herbicide-degrading Aminobacter sp. strain MSH1

DEFF Research Database (Denmark)

Schultz-Jensen, Nadja; Knudsen, Berith Elkær; Frkova, Zuzana

2014-01-01

The Aminobacter sp. strain MSH1 has potential for pesticide bioremediation because it degrades the herbicide metabolite 2,6-dichlorobenzamide (BAM). Production of the BAM-degrading bacterium using aerobic bioreactor fermentation was investigated. A mineral salt medium limited for carbon and with ......The Aminobacter sp. strain MSH1 has potential for pesticide bioremediation because it degrades the herbicide metabolite 2,6-dichlorobenzamide (BAM). Production of the BAM-degrading bacterium using aerobic bioreactor fermentation was investigated. A mineral salt medium limited for carbon...... and with an element composition similar to the strain was generated. The optimal pH and temperature for strain growth were determined using shaker flasks and verified in bioreactors. Glucose, fructose, and glycerol were suitable carbon sources for MSH1 (μ =0.1 h−1); slower growth was observed on succinate and acetic...... acid (μ =0.01 h−1). Standard conditions for growth of theMSH1 strain were defined at pH 7 and 25 °C, with glucose as the carbon source. In bioreactors (1 and 5 L), the specific growth rate of MSH1 increased from μ =0.1 h−1 on traditional mineral salt medium to μ =0.18 h−1 on the optimized mineral salt...

Interaction of bacteria-feeding soil flagellates and Pseudomonas spp

DEFF Research Database (Denmark)

Pedersen, Annette; Ekelund, Flemming; Johansen, Anders

2010-01-01

Pseudomonas strains may be used as alternatives to fungicides as some of them produce secondary metabolites, which can inhibit growth of plant pathogenic fungi. Increased knowledge of non-target effects of the antagonistic bacteria on other soil organisms as well as of the survival and predation...... resistance of the antagonistic bacteria is necessary for risk assessment and increased performance of antagonistic bacteria as biological control agents. In the present study, we aimed to investigate the difference between Pseudomonas spp. with respect to their predation resistance to and effects...... on the three different and common soil flagellates Bodo caudatus, Cercomonas longicauda, and Neocercomonas jutlandica. Two antagonistic Pseudomonas: Pseudomonas fluorescens CHA0 and P. fluorescens DR54 and two positive control strains: P. fluorescens DSM 50090T and Pseudomonas chlororaphis ATCC 43928 were...

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

Science.gov (United States)

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.

Small Rna Regulatory Networks In Pseudomonas Putida

DEFF Research Database (Denmark)

Bojanovic, Klara; Long, Katherine

2015-01-01

chemicals and has a potential to be used as an efficient cell factory for various products. P. putida KT2240 is a genome-sequenced strain and a well characterized pseudomonad. Our major aim is to identify small RNA molecules (sRNAs) and their regulatory networks. A previous study has identified 37 sRNAs...... in this strain, while in other pseudomonads many more sRNAs have been found so far.P. putida KT2440 has been grown in different conditions which are likely to be encountered in industrial fermentations with the aim of using sRNAs for generation of improved cell factories. For that, cells have been grown in LB......Pseudomonas putida is a ubiquitous Gram-negative soil bacterium with a versatile metabolism and ability to degrade various toxic compounds. It has a high tolerance to different future biobased building blocks and various other stringent conditions. It is used in industry to produce some important...

Biodegradation of shea nut cake by indigenous soil bacteria ...

African Journals Online (AJOL)

Yeast extracts enhanced growth. Pseudomanas strain G9 degraded 71.25% shea nut cake, while Pseudomonas strain G38 degraded 50.35% shea nut cake within 48 h. Pseudomonas G9 can be used to degrade shea nut cake. G9 and G38 are different species of Pseudomonas and molecular typing such as PCR can be ...

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

Science.gov (United States)

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.

ANTIMICROBIAL, ENTOMOPATHOGENIC AND ANTIVIRAL ACTIVITY OF GAUPSIN BIOPREPARATION CREATED ON THE BASIS OF Pseudomonas chlororaphis STRAINS

Directory of Open Access Journals (Sweden)

E. A. Kiprianova

2017-02-01

Full Text Available The aim of this review was to present the results of more than ten-year study of gaupsin biopreparation created on the basis of two strains Pseudomonas chlororaphis subsp. aureofaciens UCM В-111 and UCM В-306 with antifungal, entomopathogenic and antiviral activities. Data about antibiotic substances produced by these strains — phenazine and phenylpyrrole derivatives — are presented. Entomocidal properties against the wide spectrum of insect pests have been found out in the strains-producers. Antiviral activity of gaupsin due to the production of thermostable exopolymers containing neutral monosaccharides has been shown using the tobacco mosaic virus as a model. Lipopolysaccharides of the strains В-111 and В-306 also appeared to be highly active antiviral agents. Structure of their O-specific polysaccharides has been established. The last one are structurally heterogenic, presented by linear tri-and tetrasaccharide repeated links and have specific structure that has not been described previously.

Dietary curcumin prevents ocular toxicity of naphthalene in rats.

Science.gov (United States)

Pandya, U; Saini, M K; Jin, G F; Awasthi, S; Godley, B F; Awasthi, Y C

2000-06-05

Administration of naphthalene is known to cause cataract formation in rats and rabbits and naphthalene-initiated cataract is frequently used as a model for studies on senile cataract in humans. Oxidative stress has been implicated in the mechanism of naphthalene-induced cataract. Curcumin, a constituent of turmeric, a spice used in Indian curry dishes, is an effective antioxidant and is known to induce the enzymes of glutathione-linked detoxification pathways in rats. During the present studies, we have examined whether low levels of dietary curcumin could prevent naphthalene-induced opacification of rat lens. The presence of apoptotic cells in lens epithelial cells was also examined by catalytically incorporating labeled nucleotide to DNA with either Klenow fragment of DNA polymerase or by terminal deoxynucleotidyl transferase (TdT), which forms polymeric tail using the principle of TUNEL assay. The results of these studies demonstrated that the rats treated with naphthalene and kept on a diet supplemented with only 0.005% (w/w) curcumin had significantly less opacification of lenses as compared to that observed in rats treated only with naphthalene. Our studies also demonstrate, for the first time, that naphthalene-initiated cataract in lens is accompanied and perhaps preceded by apoptosis of lens epithelial cells and that curcumin attenuates this apoptotic effect of naphthalene.

Potato seed dressing with Pseudomonas aeruginosa strain RZ9 enhances yield and reduces black scurf

Directory of Open Access Journals (Sweden)

Moncef MRABET

2015-09-01

Full Text Available A rhizospheric strain RZ9 of Pseudomonas aeruginosa was assessed for in-vitro growth inhibition of Rhizoctonia solani and effectiveness to control black scurf on potatoes (Solanum tuberosum L. of the cultivars Spunta and Nicola, in greenhouse and field experiments. The strain RZ9 inhibited R. solani mycelial growth by more than 60% and completely inhibited the germination of sclerotia from infested potato tubers in in-vitro tests. In greenhouse assays, seed potato treatment with RZ9 cell suspension increased stem length, decreased the relative weight of infected potato tubers (by 67%, and increased the potato yield (by 16% compared to pathogen-inoculated plants for both potato cultivars. In field trials conducted on sandy soils during 2012 and 2013, strain RZ9 reduced black scurf incidence and increased potato yield by an average of 5.3 t ha-1 for ′Spunta′ and 5 t ha-1 for ′Nicola′. This study showed that the selected strain of P. aeruginosa is an efficient bacterium for enhancing yield and reducing black scurf of field-grown potatoes.

Effects of some organic pollutants on the exopolysaccharides (EPSs) produced by some Pseudomonas spp. strains

International Nuclear Information System (INIS)

Onbasli, Dilsad; Aslim, Belma

2009-01-01

In this study, isolation and characterization of exopolysaccharides produced by Pseudomonas aeruginosa B1, P. fluorescens B5, P. stutzeri B11 and P. putida B15 which had been seen to produce exopolymers of potential interest in biotechnological applications were examined. To initiate the observation of the organic pollutants-polymer interactions, the yield and properties of their extracellular polysaccharide were researched. The exopolysaccharide production by these strains during growth in nutrient broth medium (control) was 41-75 mg L -1 . Also, P. aeruginosa B1, P. fluorescens B5, P. stutzeri B11 and P. putida B15 had exhibited high production of EPSs in presence of various organic pollutants (2,4-D, benzene, BTX and gasoline, respectively) in mineral salt medium (MSM) as a sole carbon source. EPS production by the 4 strains ranged from 40 mg L -1 to 8 mg L -1 . Monosaccharide composition of EPS produced by these cultures were analyzed by HPLC. Results indicated that EPSs of strains contained neutral sugars and acetylated amino sugars. The neutral sugars in the EPS were mainly composed of glucose, arabinose, glycerol, ribose. The presence of galactronic acid, N-acetyl-D-galactosamin and N-acetyl-D-glucosamine indicated the acidic nature of the polysaccharide. Glycerol was the basic structural unit of EPS produced by the strains except P. stutzeri B11 (MSM with 1% BTX). Strain B1 (in NB medium) was found to be composed of neutral sugars (100%) while strain B1 [in MSM medium with 0.2% (v/v) 2.4-D] contained neutral sugars (70.0%), acetylated amino sugars (30.0%). Also, EPS content of strain B5 (in the NB medium) was neutral sugars (99.8%), acetylated amino sugars (0.2%) while the strain B5 [in MSM medium containing the 1% (v/v) benzene] was found to contain neutral sugars (99.9%), acetylated amino sugars (0.1%). However, EPS monomer composition by strain B11 was detected as neutral sugars (99.77%), acetylated amino sugars (0.23%) in NB medium while the strain B11

The growth of bacteria cells in naphthalene and ethanol-bearing systems in the presence of cadmium

Science.gov (United States)

Gomes, D. S.; Benzaquem, J.; Rogrigues Augusto, C.; Barboza, E.; Gomes Ferreira Leite, S.

2003-05-01

The present work is aimed to show thé effects of cadmium in thé growth oftwo bacteria species in the presenceof'llilplltlalele solubilized in ethanol. The Pseudomonas putida culture and 116, isolated from gasoline soil contaminated with ability to biosurfactant production, were able to growth in naphthalene ethanol until 20 ppm concentration. When a cadmium solution was added ofthis naphthaiene médium we detected a largest bacterial growth with 0.18 ppm of cadmium. We also detected um adaptation period in the growth on the 1.8 and 18 ppm oftthe metal once the final protein concentrations was almost the same in all cxperimental conditions.

Application of UV/TiO2/H2O2 Advanced Oxidation to Remove Naphthalene from Water

Directory of Open Access Journals (Sweden)

Behroz Karimi

2016-11-01

Full Text Available Naphthalene is released into the environment by burning such organic materials as fossil fuels and wood and in industrial and vehicle exhaust emissions. Naphthalene is used in the manufacture of plastics, resins, fuels, and dyes. The aim of this study was to evaluate the performance of UV/TiO2/H2O2 process to decompose naphthalene in aqueous solutions. For this purpose, the photocatalytic degradation of naphthalene was investigated under UV light irradiation in the presence of TiO2 and H2O2 under a variety of conditions. Photodegradation efficiencies of H2O2/UV, TiO2/UV, and H2O2/TiO2/UV processes were compared in a batch reactor using the low pressure mercury lamp irradiation. The effects of operating parameters such as reaction time (min; solution pH; and initial naphthalene, TiO2, and H2O2 concentrations on photodegradation were examined. In the UV/TiO2/H2O2 system with a naphthalene concentration of 15 mg/L, naphthalene removal efficiencies of 63, 75, 80, 88, 92, 95, 96.5, and 98% were achieved, respectively, for reaction times of 5, 10, 20, 30, 40, 50, 60, 100 and 120 min. This is while removal efficienciesof 50, 59.5, 69, 80, 85, 88, 91, and 95% were obtained in the UV/TiO2 system under the same conditions. For initial pH values of 3, 4, 5, 6, 7,9, 10, and 12, naphthalene removal efficiencies of approximately 96.8, 85.5, 86, 75.5, 68.8, 57.8, and 52.5% were acheived, respectively, with the UV/TiO2/H2O2 system. Thus, it may be claiomed that, compared to either H2O2/UV or TiO2/UV process, the H2O2/TiO2/UV process yielded a far more efficient photodegradation.

Bidirectional gene sequences with similar homology to functional proteins of alkane degrading bacterium pseudomonas fredriksbergensis DNA

International Nuclear Information System (INIS)

Megeed, A.A.

2011-01-01

The potential for two overlapping fragments of DNA from a clone of newly isolated alkanes degrading bacterium Pseudomonas frederiksbergensis encoding sequences with similar homology to two parts of functional proteins is described. One strand contains a sequence with high homology to alkanes monooxygenase (alkB), a member of the alkanes hydroxylase family, and the other strand contains a sequence with some homology to alcohol dehydrogenase gene (alkJ). Overlapping of the genes on opposite strands has been reported in eukaryotic species, and is now reported in a bacterial species. The sequence comparisons and ORFS results revealed that the regulation and the genes organization involved in alkane oxidation represented in Pseudomonas frederiksberghensis varies among the different known alkane degrading bacteria. The alk gene cluster containing homologues to the known alkane monooxygenase (alkB), and rubredoxin (alkG) are oriented in the same direction, whereas alcohol dehydrogenase (alkJ) is oriented in the opposite direction. Such genomes encode messages on both strands of the DNA, or in an overlapping but different reading frames, of the same strand of DNA. The possibility of creating novel genes from pre-existing sequences, known as overprinting, which is a widespread phenomenon in small viruses. Here, the origin and evolution of the gene overlap to bacteriophages belonging to the family Microviridae have been investigated. Such a phenomenon is most widely described in extremely small genomes such as those of viruses or small plasmids, yet here is a unique phenomenon. (author)

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Isolation of oxamyl-degrading bacteria and identification of cehA as a novel oxamyl hydrolase gene

Directory of Open Access Journals (Sweden)

Konstantina eRousidou

2016-04-01

Full Text Available Microbial degradation is the main process controlling the environmental dissipation of the nematicide oxamyl. Despite that, little is known regarding the microorganisms involved in its biotransformation. We report the isolation of four oxamyl-degrading bacterial strains from an agricultural soil exhibiting enhanced biodegradation of oxamyl. Multilocus sequence analysis (MLSA assigned the isolated bacteria to different subgroups of the genus Pseudomonas. The isolated bacteria hydrolyzed oxamyl to oxamyl oxime, which was not further transformed, and utilized methylamine as a C and N source. This was further supported by the detection of methylamine dehydrogenase in three of the four isolates. All oxamyl-degrading strains carried a gene highly homologous to a carbamate-hydrolase gene cehA previously identified in carbaryl- and carbofuran-degrading strains. Transcription analysis verified its direct involvement in the hydrolysis of oxamyl. Selected isolates exhibited relaxed degrading specificity and transformed all carbamates tested including the oximino carbamates aldicarb and methomyl (structurally related to oxamyl and the aryl-methyl carbamates carbofuran and carbaryl which share with oxamyl only the carbamate moiety

Characterization of the biocontrol activity of pseudomonas fluorescens strain X reveals novel genes regulated by glucose.

Directory of Open Access Journals (Sweden)

Gerasimos F Kremmydas

Full Text Available Pseudomonas fluorescens strain X, a bacterial isolate from the rhizosphere of bean seedlings, has the ability to suppress damping-off caused by the oomycete Pythium ultimum. To determine the genes controlling the biocontrol activity of strain X, transposon mutagenesis, sequencing and complementation was performed. Results indicate that, biocontrol ability of this isolate is attributed to gcd gene encoding glucose dehydrogenase, genes encoding its co-enzyme pyrroloquinoline quinone (PQQ, and two genes (sup5 and sup6 which seem to be organized in a putative operon. This operon (named supX consists of five genes, one of which encodes a non-ribosomal peptide synthase. A unique binding site for a GntR-type transcriptional factor is localized upstream of the supX putative operon. Synteny comparison of the genes in supX revealed that they are common in the genus Pseudomonas, but with a low degree of similarity. supX shows high similarity only to the mangotoxin operon of Ps. syringae pv. syringae UMAF0158. Quantitative real-time PCR analysis indicated that transcription of supX is strongly reduced in the gcd and PQQ-minus mutants of Ps. fluorescens strain X. On the contrary, transcription of supX in the wild type is enhanced by glucose and transcription levels that appear to be higher during the stationary phase. Gcd, which uses PQQ as a cofactor, catalyses the oxidation of glucose to gluconic acid, which controls the activity of the GntR family of transcriptional factors. The genes in the supX putative operon have not been implicated before in the biocontrol of plant pathogens by pseudomonads. They are involved in the biosynthesis of an antimicrobial compound by Ps. fluorescens strain X and their transcription is controlled by glucose, possibly through the activity of a GntR-type transcriptional factor binding upstream of this putative operon.

Genetic engineering of Pseudomonas putida KT2440 for rapid and high-yield production of vanillin from ferulic acid.

Science.gov (United States)

Graf, Nadja; Altenbuchner, Josef

2014-01-01

Vanillin is one of the most important flavoring agents used today. That is why many efforts have been made on biotechnological production from natural abundant substrates. In this work, the nonpathogenic Pseudomonas putida strain KT2440 was genetically optimized to convert ferulic acid to vanillin. Deletion of the vanillin dehydrogenase gene (vdh) was not sufficient to prevent vanillin degradation. Additional inactivation of a molybdate transporter, identified by transposon mutagenesis, led to a strain incapable to grow on vanillin as sole carbon source. The bioconversion was optimized by enhanced chromosomal expression of the structural genes for feruloyl-CoA synthetase (fcs) and enoyl-CoA hydratase/aldolase (ech) by introduction of the strong tac promoter system. Further genetic engineering led to high initial conversion rates and molar vanillin yields up to 86% within just 3 h accompanied with very low by-product levels. To our knowledge, this represents the highest productivity and molar vanillin yield gained with a Pseudomonas strain so far. Together with its high tolerance for ferulic acid, the developed, plasmid-free P. putida strain represents a promising candidate for the biotechnological production of vanillin.

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

Science.gov (United States)

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.

Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part A-Monocyclic and Polycyclic Aromatic Hydrocarbons.

Science.gov (United States)

Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

2015-08-01

Present study focused on the screening of bacterial consortium for biodegradation of monocyclic aromatic hydrocarbon (MAH) and polycyclic aromatic hydrocarbons (PAHs). Target compounds in the present study were naphthalene, acenaphthene, phenanthrene (PAHs), and benzene (MAH). Microbial consortia enriched with the above target compounds were used in screening experiments. Naphthalene-enriched consortium was found to be the most efficient consortium, based on its substrate degradation rate and its ability to degrade other aromatic pollutants with significantly high efficiency. Substrate degradation rate with naphthalene-enriched culture followed the order benzene > naphthalene > acenaphthene > phenanthrene. Chryseobacterium and Rhodobacter were discerned as the predominant species in naphthalene-enriched culture. They are closely associated to the type strain Chryseobacterium arthrosphaerae and Rhodobacter maris, respectively. Single substrate biodegradation studies with naphthalene (PAH) and benzene (MAH) were carried out using naphthalene-enriched microbial consortium (NAPH). Phenol and 2-hydroxybenzaldehyde were identified as the predominant intermediates during benzene and naphthalene degradation, respectively. Biodegradation of toluene, ethyl benzene, xylene, phenol, and indole by NAPH was also investigated. Monod inhibition model was able to simulate biodegradation kinetics for benzene, whereas multiple substrate biodegradation model was able to simulate biodegradation kinetics for naphthalene.

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

Science.gov (United States)

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.

Draft genome sequences of eight bacteria isolated from the indoor environment: Staphylococcus capitis strain H36, S. capitis strain H65, S. cohnii strain H62, S. hominis strain H69, Microbacterium sp. strain H83, Mycobacterium iranicum strain H39, Plantibacter sp. strain H53, and Pseudomonas oryzihabitans strain H72

OpenAIRE

Lymperopoulou, Despoina S.; Coil, David A.; Schichnes, Denise; Lindow, Steven E.; Jospin, Guillaume; Eisen, Jonathan A.; Adams, Rachel I.

2017-01-01

We report here the draft genome sequences of eight bacterial strains of the genera Staphylococcus, Microbacterium, Mycobacterium, Plantibacter, and Pseudomonas. These isolates were obtained from aerosol sampling of bathrooms of five residences in the San Francisco Bay area. Taxonomic classifications as well as the genome sequence and gene annotation of the isolates are described. As part of the ?Built Environment Reference Genome? project, these isolates and associated genome data provide val...

Bioaugmentation of a 4-chloronitrobenzene contaminated soil with Pseudomonas putida ZWL73

Energy Technology Data Exchange (ETDEWEB)

Guilan, Niu [State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Junjie, Zhang [State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China); Shuo, Zhao [State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Hong, Liu [State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China); Boon, Nico [Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Gent (Belgium); Zhou Ningyi [State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China)], E-mail: n.zhou@pentium.whiov.ac.cn

2009-03-15

The strain Pseudomonas putida ZWL73, which metabolizes 4-chloronitrobenzene (4CNB) by a partial-reductive pathway, was inoculated into lab-scale 4CNB-contaminated soil for bioaugmentation purposes in this study. The degradation of 4CNB was clearly stimulated, as indicated with the gradual accumulation of ammonium and chloride. Simultaneously, the diversity and quantity of cultivable heterotrophic bacteria decreased due to 4CNB contamination, while the quantity of 4CNB-resistant bacteria increased. During the bioaugmentation, denaturing gradient gel electrophoresis analysis showed the changes of diversity in dominant populations of intrinsic soil microbiota. The results showed that Alphaproteobacteria and Betaproteobacteria were not distinctly affected, but Actinobacteria were apparently stimulated. In addition, an interesting dynamic within Acidobacteria was observed, as well as an influence on ammonia-oxidizing bacteria population. These combined findings demonstrate that the removal of 4CNB in soils by inoculating strain ZWL73 is feasible, and that specific populations in soils rapidly changed in response to 4CNB contamination and subsequent bioaugmentation. - Pseudomonas putida ZWL73 can accelerate 4CNB removal in lab-scale soils, causing dynamic changes within intrinsic Actinobacteria and Acidobacteria.

Bioaugmentation of a 4-chloronitrobenzene contaminated soil with Pseudomonas putida ZWL73

International Nuclear Information System (INIS)

Niu Guilan; Zhang Junjie; Zhao Shuo; Liu Hong; Boon, Nico; Zhou Ningyi

2009-01-01

The strain Pseudomonas putida ZWL73, which metabolizes 4-chloronitrobenzene (4CNB) by a partial-reductive pathway, was inoculated into lab-scale 4CNB-contaminated soil for bioaugmentation purposes in this study. The degradation of 4CNB was clearly stimulated, as indicated with the gradual accumulation of ammonium and chloride. Simultaneously, the diversity and quantity of cultivable heterotrophic bacteria decreased due to 4CNB contamination, while the quantity of 4CNB-resistant bacteria increased. During the bioaugmentation, denaturing gradient gel electrophoresis analysis showed the changes of diversity in dominant populations of intrinsic soil microbiota. The results showed that Alphaproteobacteria and Betaproteobacteria were not distinctly affected, but Actinobacteria were apparently stimulated. In addition, an interesting dynamic within Acidobacteria was observed, as well as an influence on ammonia-oxidizing bacteria population. These combined findings demonstrate that the removal of 4CNB in soils by inoculating strain ZWL73 is feasible, and that specific populations in soils rapidly changed in response to 4CNB contamination and subsequent bioaugmentation. - Pseudomonas putida ZWL73 can accelerate 4CNB removal in lab-scale soils, causing dynamic changes within intrinsic Actinobacteria and Acidobacteria

Screening of an oil-degrading strain by N+ implantation and the oil degradation conditions

International Nuclear Information System (INIS)

Yan Yajuan; Li Zongwei; Qin Guangyong; Liu Jianling

2008-01-01

A strain DC-3-2-50 was obtained through N + implanting into Yarrowia lipolytica DC-3-2. An increase of 11.09% in the oil-degradation rate was obtained. The stain has good genetic stability after 10 times of subculture. The culturing condition of DC-3-2-50 was studied. The optimal culture conditions were as follow: initial pH value, 9.0; inoculum size, 3%; temperature, 25-28 degree C; dissolved oxygen, 180-200 rpm; and carbon nutriments soybean salad oil. The off-degradation rate can be up to 87.7%. (authors)

Continuous degradation of trichloroethylene by Xanthobacter sp. strain Py2 during growth on propene.

OpenAIRE

Reij, M W; Kieboom, J; de Bont, J A; Hartmans, S

1995-01-01

Propene-grown Xanthobacter sp. strain Py2 cells can degrade trichloroethylene (TCE), but the transformation capacity of such cells was limited and depended on both the TCE concentration and the biomass concentration. Toxic metabolites presumably accumulated extracellularly, because the fermentation of glucose by yeast cells was inhibited by TCE degradation products formed by strain Py2. The affinity of the propene monooxygenase for TCE was low, and this allowed strain Py2 to grow on propene i...

Typing of Pseudomonas aeruginosa strains in Norwegian cystic fibrosis patients

DEFF Research Database (Denmark)

Fluge, G; Ojeniyi, B; Høiby, N

2001-01-01

OBJECTIVES: Typing of Pseudomonas aeruginosa isolates from Norwegian cystic fibrosis (CF) patients with chronic Pseudomonas lung infection in order to see whether cross-infection might have occurred. METHODS: Isolates from 60 patients were collected during the years 1994-98, and typed by pulsed...

Effect of Indigenous Pseudomonas sp. and Bacillus sp. Strains on Yield and Main Chemical Growth Parameters of Radicchio

Directory of Open Access Journals (Sweden)

Stanojković-Sebić Aleksandra

2018-03-01

Full Text Available Pseudomonas sp. and Bacillus sp. belong to plant growth promoting rhizobacteria which are able to colonize the plants roots and stimulate growth. In this study, the effect of two indigenous plant growth promoting rhizobacterial strains Pseudomonas sp. Q4 and Bacillus sp. Q10 and their mixture (mix Q4+Q10 on content of the main chemical growth parameters (nitrogen, phosphorus, potassium, calcium and magnesium and the yield of dry biomass of radicchio (Cichorium spp. var. rossa di treviso aerial parts and root, was investigated. The study was carried out with stagnosol type of soil in pot experiments under semi-controlled conditions in the Institute of Soil Science (Belgrade, in the period from July to October in 2013. Phosphorus was determined by spectrophotometer, potassium - by flame emission photometry and total nitrogen and carbon - using elemental CNS analyzer, while calcium and magnesium were determined by AAS. The data on yield of both aerial parts and root dry biomass of radicchio showed that its treatment with Q4 and Q10 strains, as well as with their mixture, caused noticeably increase in this parameter in relation to the control, whereby the strain Q4 was more effective for aerial parts, while mix Q4+Q10 - for roots. The obtained data on the studied chemical parameters of radicchio root and aerial parts were in total accordance with their yield. Concluding, studied strains have a potential in promoting the biomass yield and main chemical growth parameters of both aerial parts and root of radicchio.

Degradation of volatile hydrocarbons from steam-classified solid waste by a mixture of aromatic hydrocarbon-degrading bacteria.

Science.gov (United States)

Leahy, Joseph G; Tracy, Karen D; Eley, Michael H

2003-03-01

Steam classification is a process for treatment of solid waste that allows recovery of volatile organic compounds from the waste via steam condensate and off-gases. A mixed culture of aromatic hydrocarbon-degrading bacteria was used to degrade the contaminants in the condensate, which contained approx. 60 hydrocarbons, of which 38 were degraded within 4 d. Many of the hydrocarbons, including styrene, 1,2,4-trimethylbenzene, naphthalene, ethylbenzene, m-/p-xylene, chloroform, 1,3-dichloropropene, were completely or nearly completely degraded within one day, while trichloroethylene and 1,2,3-trichloropropane were degraded more slowly.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Pseudomonas versuta sp. nov., isolated from Antarctic soil.

Science.gov (United States)

See-Too, Wah Seng; Salazar, Sergio; Ee, Robson; Convey, Peter; Chan, Kok-Gan; Peix, Álvaro

2017-06-01

In this study we analysed three bacterial strains coded L10.10 T , A4R1.5 and A4R1.12, isolated in the course of a study of quorum-quenching bacteria occurring in Antarctic soil. The 16S rRNA gene sequence was identical in the three strains and showed 99.7% pairwise similarity with respect to the closest related species Pseudomonas weihenstephanensis WS4993 T . Therefore, the three strains were classified within the genus Pseudomonas. Analysis of housekeeping genes (rpoB, rpoD and gyrB) sequences showed similarities of 84-95% with respect to the closest related species of Pseudomonas, confirming its phylogenetic affiliation. The ANI values were less than 86% to the closest related species type strains. The respiratory quinone is Q9. The major fatty acids are C16:0, C16:1 ω7c/ C16:1 ω6c in summed feature 3 and C18:1 ω7c / C18:1 ω6c in summed feature 8. The strains are oxidase- and catalase-positive. Growth occurs at 4-30°C, and at pH 4.0-10. The DNA G+C content is 58.2-58.3mol %. The combined genotypic, phenotypic and chemotaxonomic data support the classification of strains L10.10 T , A4R1.5 and A4R1.12 into a novel species of Pseudomonas, for which the name P. versuta sp. nov. is proposed. The type strain is L10.10 T (LMG 29628 T , DSM 101070 T ). Copyright © 2017 Elsevier GmbH. All rights reserved.

Pseudomonas A1 influences the formation of hydroxyapatite and degrades bioglass

International Nuclear Information System (INIS)

Papadopoulou, E.; Papadopoulou, L.; Paraskevopoulos, K.M.; Koidis, P.; Sivropoulou, A.

2009-01-01

Bacterial infections frequently lead to hard tissue destructions. The purpose of the present study was to address the question as to how the bacteria destroy hard tissues with the use of an in vitro system. A bacterium was isolated from a solution simulating body fluid which was identified as Pseudomonas A1, and is able to solubilize tricalcium phosphate when it grows in IP broth. The presence of Pseudomonas A1 resulted in dose-dependent inhibition of the formation of hydroxyapatite layer, on the surface of bioglass specimens immersed in SBF solution, in contrast to the control. When the bioglass specimens were immersed in IP broth without Ca 3 (PO 4 ) 2 , so as to be present the appropriate inorganic ions for the survival of Pseudomonas but the only source of phosphate be derived from bioactive glass specimens, the formation of hydroxyapatite layer was not observed in any specimen. Additionally the presence of Pseudomonas resulted in 93.4% (w/w) and 85.9% (w/w) reduction on the surface composition of Ca and P, respectively, and further the rate of the decrease of specimen's weight was almost 50% higher in the presence of Pseudomonas compared with the control.

Pseudomonas oceani sp. nov., isolated from deep seawater.

Science.gov (United States)

Wang, Ming-Qing; Sun, Li

2016-10-01

In this study, we identified a novel Gram-stain-negative, aerobic, motile, and rod-shaped bacterium, strain KX 20T, isolated from the deep seawater in Okinawa Trough, northwestern Pacific Ocean. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain KX 20T was related to members of the genus Pseudomonas and shares the highest sequence identities with Pseudomonas aestusnigri CECT 8317T (99.4 %) and Pseudomonas pachastrellae JCM 12285T (98.5 %). The 16S rRNA gene sequence identities between strain KX 20T and other members of the genus Pseudomonaswere below 96.6 %. The gyrB and rpoD genes of strain KX 20T shared 82.0 to 89.3 % sequence identity with the gyrB and rpoD genes of the closest phylogenetic neighbours of KX 20T. The predominant cellular fatty acids of strain KX 20T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) (29.2 %), C16 : 0 (24.5 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (21.5 %) and C12 : 0 (8.2 %). The major polar lipids of strain KX 20T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unknown phospholipids. The genomic DNA G+C content of strain KX 20T was 62.9 mol%. On the basis of phylogenetic analysis and phenotypic characteristics, a novel species, Pseudomonas oceani sp. nov. is proposed. The type strain is KX 20T (=CGMCC 1.15195T=DSM 100277T).

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

Science.gov (United States)

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.

Pseudomonas salina sp. nov., isolated from a salt lake.

Science.gov (United States)

Zhong, Zhi-Ping; Liu, Ying; Hou, Ting-Ting; Liu, Hong-Can; Zhou, Yu-Guang; Wang, Fang; Liu, Zhi-Pei

2015-09-01

A Gram-staining-negative, facultatively aerobic bacterium, strain XCD-X85(T), was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9%, w/v) in Qaidam basin, Qinghai province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X85(T) were non-endospore-forming rods, 0.4-0.6 μm wide and 1.0-1.6 μm long, and motile by means of a single polar flagellum. Strain XCD-X85(T) was catalase- and oxidase-positive. Growth was observed in the presence of 0-12.0% (w/v) NaCl (optimum, 1.0-2.0%) and at 4-35 °C (optimum, 25-30 °C) and pH 6.5-10.5 (optimum, pH 8.0-8.5). Strain XCD-X85(T) contained (>10%) summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C12 : 0, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the predominant fatty acids. The major respiratory quinone was ubiquinone 9 (Q-9). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 57.4 mol%. Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X85(T) was associated with the genus Pseudomonas, and showed highest 16S rRNA gene sequence similarities to Pseudomonas pelagia CL-AP6(T) (99.0%) and Pseudomonas bauzanensis BZ93(T) (96.8%). DNA-DNA relatedness of strain XCD-X85T to P. pelagia JCM 15562(T) was 19 ± 1%. On the basis of the data presented above, it is concluded that strain XCD-X85(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas salina sp. nov. is proposed. The type strain is XCD-X85(T) ( = CGMCC 1.12482(T) = JCM 19469(T)).

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

NARCIS (Netherlands)

Oosterkamp, M.J.; Boeren, S.; Atashgahi, S.; Plugge, C.M.; Schaap, P.J.; Stams, A.J.M.

2015-01-01

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

Purification and properties of a novel quizalofop-p-ethyl-hydrolyzing esterase involved in quizalofop-p-ethyl degradation by Pseudomonas sp. J-2.

Science.gov (United States)

Zhang, Hui; Li, Mengya; Li, Jie; Wang, Guangli; Liu, Yuan

2017-05-10

Quizalofop-p-ethyl (QPE) is a post-emergence herbicide that effectively controls grass weeds and is often detected in the environment. However, the biochemical and molecular mechanisms of QPE degradation in the environment remains unclear. In this study, a highly effective QPE-degrading bacterial strain J-2 was isolated from acclimated activated sludge and identified as a Pseudomonas sp., containing the QPE breakdown metabolite quizalofop acid (QA) identified by Liquid Chromatography-Ion Trap-Mass Spectrometry (LC-IT-MS n ) analysis. A novel QPE hydrolase esterase-encoding gene qpeH was cloned from strain J-2 and functionally expressed in Escherichia coli BL21 (DE3). The specific activity of recombinant QpeH was 198.9 ± 2.7 U mg -1 for QPE with K m and K cat values of 41.3 ± 3.6 μM and 127.3 ± 4.5 s -1 . The optimal pH and temperature for the recombinant QpeH were 8.0 and 30 °C, respectively and the enzyme was activated by Ca 2+ , Cd 2+ , Li + , Fe 3+ and Co 2+ and inhibited by Ni 2+ , Fe 2+ , Ag + , DEPC, SDS, Tween 80, Triton X, β-mercaptoethanol, PMSF, and pCMB. In addition, the catalytic efficiency of QpeH toward different AOPP herbicides in descending order was as follows: fenoxaprop-P-ethyl > quizalofop-P-tefuryl > QPE > haloxyfop-P-methyl > cyhalofopbutyl > clodinafop-propargyl. On the basis of the phylogenetic analysis and multiple sequence alignment, the identified enzyme QpeH, was clustered with esterase family V, suggesting a new member of this family because of its low similarity of amino acid sequence with esterases reported previously.

Synthesis and Photophysical Characterizations of Thermal -Stable Naphthalene Benzimidazoles

OpenAIRE

Erten Ela, Şule; Özçelik, Serdar; Eren, Ersin

2011-01-01

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 ...

The inoculation method affects colonization and performance of bacterial inoculant strains in the phytoremediation of soil contaminated with diesel oil.

Science.gov (United States)

Afzal, Muhammad; Yousaf, Sohail; Reichenauer, Thomas G; Sessitsch, Angela

2012-01-01

Plants in combination with microorganisms can remediate soils, which are contaminated with organic pollutants such as petroleum hydrocarbons. Inoculation of plants with degrading bacteria is one approach to improve remediation processes, but is often not successful due to the competition with resident microorganisms. It is therefore of high importance to address the persistence and colonization behavior of inoculant strains. The objective of this study was to determine whether the inoculation method (seed imbibement and soil inoculation) influences bacterial colonization, plant growth promotion and hydrocarbon degradation. Italian ryegrass was grown in non-sterilized soil polluted with diesel and inoculated with different alkane-degrading strains Pantoea sp. ITSI10, Pantoea sp. BTRH79 and Pseudomonas sp. MixRI75 individually as well as in combination. Inoculation generally had a beneficial effect on plant biomass production and hydrocarbon degradation, however, strains inoculated in soil performed better than applied by seed imbibement. Performance correlated with the colonization efficiency of the inoculated strains. The highest hydrocarbon degradation was observed in the treatment, in which all three strains were inoculated in combination into soil. Our study revealed that besides the degradation potential and competitive ability of inoculant strains the inoculation method plays an important role in determining the success of microbial inoculation.

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

Science.gov (United States)

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

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

Science.gov (United States)

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

Science.gov (United States)

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

Pseudomonas A1 influences the formation of hydroxyapatite and degrades bioglass

Energy Technology Data Exchange (ETDEWEB)

Papadopoulou, E. [Laboratory of General Microbiology, Section of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Papadopoulou, L. [School of Geology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Paraskevopoulos, K.M. [Physics Department Solid State Physics Section, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Koidis, P. [Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Sivropoulou, A., E-mail: asivropo@bio.auth.g [Laboratory of General Microbiology, Section of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)

2009-12-15

Bacterial infections frequently lead to hard tissue destructions. The purpose of the present study was to address the question as to how the bacteria destroy hard tissues with the use of an in vitro system. A bacterium was isolated from a solution simulating body fluid which was identified as Pseudomonas A1, and is able to solubilize tricalcium phosphate when it grows in IP broth. The presence of Pseudomonas A1 resulted in dose-dependent inhibition of the formation of hydroxyapatite layer, on the surface of bioglass specimens immersed in SBF solution, in contrast to the control. When the bioglass specimens were immersed in IP broth without Ca{sub 3}(PO{sub 4}){sub 2}, so as to be present the appropriate inorganic ions for the survival of Pseudomonas but the only source of phosphate be derived from bioactive glass specimens, the formation of hydroxyapatite layer was not observed in any specimen. Additionally the presence of Pseudomonas resulted in 93.4% (w/w) and 85.9% (w/w) reduction on the surface composition of Ca and P, respectively, and further the rate of the decrease of specimen's weight was almost 50% higher in the presence of Pseudomonas compared with the control.

PseudoMLSA: a database for multigenic sequence analysis of Pseudomonas species

Directory of Open Access Journals (Sweden)

Lalucat Jorge

2010-04-01

Full Text Available Abstract Background The genus Pseudomonas comprises more than 100 species of environmental, clinical, agricultural, and biotechnological interest. Although, the recommended method for discriminating bacterial species is DNA-DNA hybridisation, alternative techniques based on multigenic sequence analysis are becoming a common practice in bacterial species discrimination studies. Since there is not a general criterion for determining which genes are more useful for species resolution; the number of strains and genes analysed is increasing continuously. As a result, sequences of different genes are dispersed throughout several databases. This sequence information needs to be collected in a common database, in order to be useful for future identification-based projects. Description The PseudoMLSA Database is a comprehensive database of multiple gene sequences from strains of Pseudomonas species. The core of the database is composed of selected gene sequences from all Pseudomonas type strains validly assigned to the genus through 2008. The database is aimed to be useful for MultiLocus Sequence Analysis (MLSA procedures, for the identification and characterisation of any Pseudomonas bacterial isolate. The sequences are available for download via a direct connection to the National Center for Biotechnology Information (NCBI. Additionally, the database includes an online BLAST interface for flexible nucleotide queries and similarity searches with the user's datasets, and provides a user-friendly output for easily parsing, navigating, and analysing BLAST results. Conclusions The PseudoMLSA database amasses strains and sequence information of validly described Pseudomonas species, and allows free querying of the database via a user-friendly, web-based interface available at http://www.uib.es/microbiologiaBD/Welcome.html. The web-based platform enables easy retrieval at strain or gene sequence information level; including references to published peer

Post-secretional activation of Protease IV by quorum sensing in Pseudomonas aeruginosa.

Science.gov (United States)

Oh, Jungmin; Li, Xi-Hui; Kim, Soo-Kyong; Lee, Joon-Hee

2017-06-30

Protease IV (PIV), a key virulence factor of Pseudomonas aeruginosa is a secreted lysyl-endopeptidase whose expression is induced by quorum sensing (QS). We found that PIV expressed in QS mutant has severe reduction of activity in culture supernatant (CS), even though it is overexpressed to high level. PIV purified from the QS mutant (M-PIV) had much lower activity than the PIV purified from wild type (P-PIV). We found that the propeptide cleaved from prepro-PIV was co-purified with M-PIV, but never with P-PIV. Since the activity of M-PIV was restored by adding the CS of QS-positive and PIV-deficient strain, we hypothesized that the propeptide binds to and inhibits PIV, and is degraded to activate PIV by a QS-dependent factor. In fact, the CS of the QS-positive and PIV-deficient strain was able to degrade the propeptide. Since the responsible factor should be a QS-dependently expressed extracellular protease, we tested QS-dependent proteases of P. aeruginosa and found that LasB (elastase) can degrade the propeptide and activate M-PIV. We purified the propeptide of PIV and confirmed that the propeptide can bind to and inhibit PIV. We suggest that PIV is post-secretionally activated through the extracellular degradation of the propeptide by LasB, a QS-dependent protease.

Research on heavy oil degradation by four thermophilic bacterial strains

Energy Technology Data Exchange (ETDEWEB)

Bao, M.; Chen, Q.; Liu, Z.; Li, Y. [Ocean Univ. of China, Qingdao, Shandong (China)

2009-07-01

The Shengli oilfield is the second largest onshore oil field in China, with a crude oil output of approximately 30 million tons per year. The large quantities of wastewater that are produced during thermal recovery methods have posed a challenge in terms of water reuse, reinjection and discharge. The important aspect of wastewater treatment is the removal of residual heavy oil. Biological methods are considered to be efficient in solving this problem. This paper reported on a study in which 4 thermophilic microorganisms which had the ability to biodegrade heavy oil were screened from heavy oil wastewater in the Shengli oilfield. Their degradation to heavy oil was discussed and the suitable biodegradation conditions of these bacteria were investigated. The study showed that the degrading efficiency of heavy oil by the 4 bacteria was up to 42.0, 47.6, 55.6 and 43.4 per cent in the wastewater which contained 500 mg per litre of heavy oil, respectively. The crude oil samples were analyzed using gas chromatography/flame ionization detection (GC/FID) and gas chromatography/mass spectrometry (GC/MS) before and after degradation. The single 4 strains demonstrated strong biodegradability to normal alkanes and aromatics, and the average degrading efficiency was about 50 and 35 per cent. The degrading efficiency of the mixed 4 strains was better than the single ones, particularly for the poor biodegradable hydrocarbons such as phenanthrenes and fluorines. 21 refs., 2 tabs., 17 figs.

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

Science.gov (United States)

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.

Science.gov (United States)

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

Uniaxial Strain Induced Critical Current Degradation of Ag-Sheathed Bi-2212 Round Wire

NARCIS (Netherlands)

Dai, Chao; Qin, Jinggang; Liu, Bo; Liu, Peihang; Wu, Yu; Nijhuis, Arend; Zhou, Chao; Li, Chenshan; Hao, Qingbin; Liu, Sheng

2018-01-01

The critical current degradation of Bi-2212 Ag-sheathed round wire subjected to uniaxial strain was studied at 4.2 K in 14 T background field. The strains applied on the sample are both tension and compression. The additional tensile strain caused by the difference in thermal expansion between the

Anti-Toxoplasma Activity of 2-(Naphthalene-2-γlthiol-1H Indole.

Directory of Open Access Journals (Sweden)

Qasem Asgari

2015-06-01

Full Text Available This study was undertaken to evaluate the viability, infectivity and immunity of Toxoplasma gondii tachyzoites exposed to 2-(naphthalene-2-ylthio-1H-indole.Tachyzoites of RH strain were incubated in various concentrations of 2-(naphthalene-2-ylthio-1H-indole (25-800 μM for 1.5 hours. Then, they were stained by PI and analyzed by Fluorescence-activated cell sorting (FACS. To evaluate the infectivity, the tachyzoites exposed to the different concentrations of the compound were inoculated to 10 BALB/c mice groups. For Control, parasites exposed to DMSO (0.2% v/v were also intraperitoneally inoculated into two groups of mice. The immunity of the exposed tachyzoites was evaluated by inoculation of the naïve parasite to the survived mice.The LD50 of 2-(naphthalene-2-ylthio-1H-indole was 57 μmol. The longevity of mice was dose dependent. Five mice out of group 400μmol and 3 out of group 800μmol showed immunization to the parasite.Our findings demonstrated the toxoplasmocidal activity of the compound. The presence of a well-organized transporter mechanism for indole compounds within the parasite in conjunction with several effective mechanisms of these compounds on Toxoplasma viability would open a window for production of new drugs and vaccines.

The Ssr protein (T1E_1405) from Pseudomonas putida DOT-T1E enables oligonucleotide-based recombineering in platform strain P. putida EM42

DEFF Research Database (Denmark)

Aparicio, Tomás; Ingemann Jensen, Sheila; Nielsen, Alex Toftgaard

2016-01-01

Some strains of the soil bacterium Pseudomonas putida have become in recent years platforms of choice for hosting biotransformations of industrial interest. Despite availability of many genetic tools for this microorganism, genomic editing of the cell factory P. putida EM42 (a derivative of refer......Some strains of the soil bacterium Pseudomonas putida have become in recent years platforms of choice for hosting biotransformations of industrial interest. Despite availability of many genetic tools for this microorganism, genomic editing of the cell factory P. putida EM42 (a derivative...

Studies on Post-Irradiation DNA Degradation in Micrococcus Radiodurans, Strain RII51

DEFF Research Database (Denmark)

Auda, H.; Emborg, C.

1973-01-01

The influence of irradiation condition on post-irradiation DNA degradation was studied in a radiation resistant mutant of M. radiodurans, strain ${\\rm R}_{{\\rm II}}5$. After irradiation with 1 Mrad or higher more DNA is degraded in cells irradiated in wet condition than in cells irradiated with t...

Forage Quantity and Quality of Berseem Clover (Trifolium ‎alexandrinum L. as Affected by Uses of Pseudomonas putida ‎Strains and Phophorus Fertilizer in the Second Crop

Directory of Open Access Journals (Sweden)

Mohammad Hossein Ansari

2017-05-01

Full Text Available Effects of phosphate fertilizer and pseudomonas putida strains on the quantity and quality of forage of berseem clover as a second crop was studied in a factorial field experiment using randomized complete block design with three replications at Fooman, Guilan province, Iran. Treatments consisted of phosphate fertilizer with three levels (0, 75 and 150 kg/ha as triple super phosphate and Pseudomonas putida strains with four levels (M21, M5, M168 and control. The results showed that use of phosphate fertilizers increased the soil pH during growing season while bacterial inoculation adjusted soil pH. The bacterial inoculation increased amount of crude protein, digestible protein, acidic and alkaline phosphatase activity compared to non-inoculated treatment, but it decreased crude fiber of the forage. Clover forage yield, protein yield and phosphorus content of foliage also were influenced by the interaction of bacterial strains and phosphate fertilizer. The highest forage and protein yield were obtained by using strain M5+150 kg P ha-1. Significant increases in forage and protein yield were found to be 16.49% and 8.01%, respectively, as compared with non-inoculated treatment. Based on the result of this experiment, application of 150 kg P ha-1 and Pseudomonas putida strain M5 inoculation can be used to obtain highest forage yield and quality of berseem clover as second crop in the experimental site.

Draft Genome Sequence of Advenella kashmirensis Strain W13003, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium

Science.gov (United States)

Jin, Decai; Zhou, Lisha; Wu, Liang; An, Wei; Zhao, Lin

2014-01-01

Advenella kashmirensis strain W13003 is a polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from PAH-contaminated marine sediments. Here, we report the 4.8-Mb draft genome sequence of this strain, which will provide insights into the diversity of A. kashmirensis and the mechanism of PAH degradation in the marine environment. PMID:24482505

Selection of bacteria with hydrocarbon degrading capacity isolated from Colombian Caribbean sediments

International Nuclear Information System (INIS)

Narvaez Florez, Silvia; Gomez, Martha L; Martinez Maria M

2008-01-01

Thirty one bacterial isolations in minimal salts supplemented medium with hydrocarbons (ACPM or crude oil) as sole carbon source were isolated from sediment samples from the Colombian Caribbean. Bacterial strains underwent selection tests in different concentrations of hydrocarbons; 11 tolerant crude oil and ACPM strains in a range of 1-8%v/v were chosen. A mixed bacterial culture was created and assessed its ability to degrade hydrocarbons in a laboratory-scale test, with a concentration of 2% v/v of ACPM over a period of 21 days. Measurements of biomass in Colony Forming Units (CFU)/mL were used to develop the growth curve of the mixed culture. Hydrocarbons remotion was measured by mass chromatography. The mixed culture was able to degrade the 68.6% of aliphatic hydrocarbons in preference of long chain n- alkenes (C12- C31), reaching a maximum growth of 3.13 x 10 9 UFC / mL. Degradation of aromatic hydrocarbons was not evidenced under the observation time. Nine of the eleven strains were identified using the biochemical systems BBL and API 50 CHB/E; they belonged to the genus Klebsiella, Chromobacterium, Flavimonas, Enterobacter,Pseudomonas, and Bacillus. The evaluated strains have enzymatic potential to degrade hydrocarbons and it is necessary to characterize them at molecular level in order to develop and effective consortium for field application

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

Science.gov (United States)

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

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

Science.gov (United States)

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, degrading consortia in sea water and surface sediment of Middle Atlantic Ridge deep sea, with Novosphingobium spp. as their main PAHs degraders.

Draft Genome Sequence of the Phosphate-Solubilizing Bacterium Pseudomonas argentinensis Strain SA190 Isolated from the Desert Plant Indigofera argentea

KAUST Repository

Lafi, Feras Fawzi

2016-12-23

Pseudomonas argentinensis strain SA190 is a plant endophytic-inhabiting bacterium that was isolated from root nodules of the desert plant Indigofera argentea collected from the Jizan region of Saudi Arabia. Here, we report the genome sequence of SA190, highlighting several functional genes related to plant growth-promoting activity, environment adaption, and antifungal activity.

Distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea

International Nuclear Information System (INIS)

Bruns, K.; Dahlmann, G.; Gunkel, W.

1993-01-01

Data were collected in 1988 and 1989 on the distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea. Crude oil degrading bacteria and the number of bacteria which in particular degrade naphthalene were quantified using a modified dilution method (MPN). Crude oil degrading bacteria were present in all of about 100 water samples, with as many as 10 3 ml -1 in some samples. Numbers of naphthalene degrading bacteria were at least tenfold lower. There is obviously a greater connection between this bacteria group and petroleum hydrocarbon (PHC) contamination than between the more nonspecific group of crude oil degrading bacteria and PHC contamination. Data from the North Sea show an extremely high abundance of hydrocarbon degrading bacteria, even in winter, while in the southern Baltic Sea low numbers of bacteria were found and slower crude oil degradation was observed. (orig.)

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

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

Murphy Anna

2010-07-01

Full Text Available Abstract 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.

Combinatorial metabolic engineering of Pseudomonas putida KT2440 for efficient mineralization of 1,2,3-trichloropropane.

Science.gov (United States)

Gong, Ting; Xu, Xiaoqing; Che, You; Liu, Ruihua; Gao, Weixia; Zhao, Fengjie; Yu, Huilei; Liang, Jingnan; Xu, Ping; Song, Cunjiang; Yang, Chao

2017-08-01

An industrial waste, 1,2,3-trichloropropane (TCP), is toxic and extremely recalcitrant to biodegradation. To date, no natural TCP degraders able to mineralize TCP aerobically have been isolated. In this work, we engineered a biosafety Pseudomonas putida strain KT2440 for aerobic mineralization of TCP by implantation of a synthetic biodegradation pathway into the chromosome and further improved TCP mineralization using combinatorial engineering strategies. Initially, a synthetic pathway composed of haloalkane dehalogenase, haloalcohol dehalogenase and epoxide hydrolase was functionally assembled for the conversion of TCP into glycerol in P. putida KT2440. Then, the growth lag-phase of using glycerol as a growth precursor was eliminated by deleting the glpR gene, significantly enhancing the flux of carbon through the pathway. Subsequently, we improved the oxygen sequestering capacity of this strain through the heterologous expression of Vitreoscilla hemoglobin, which makes this strain able to mineralize TCP under oxygen-limited conditions. Lastly, we further improved intracellular energy charge (ATP/ADP ratio) and reducing power (NADPH/NADP + ratio) by deleting flagella-related genes in the genome of P. putida KT2440. The resulting strain (named KTU-TGVF) could efficiently utilize TCP as the sole source of carbon for growth. Degradation studies in a bioreactor highlight the value of this engineered strain for TCP bioremediation.

Draft genome sequences of eight bacteria isolated from the indoor environment: Staphylococcus capitis strain H36, S. capitis strain H65, S. cohnii strain H62, S. hominis strain H69, Microbacterium sp. strain H83, Mycobacterium iranicum strain H39, Plantibacter sp. strain H53, and Pseudomonas oryzihabitans strain H72.

Science.gov (United States)

Lymperopoulou, Despoina S; Coil, David A; Schichnes, Denise; Lindow, Steven E; Jospin, Guillaume; Eisen, Jonathan A; Adams, Rachel I

2017-01-01

We report here the draft genome sequences of eight bacterial strains of the genera Staphylococcus , Microbacterium, Mycobacterium, Plantibacter, and Pseudomonas . These isolates were obtained from aerosol sampling of bathrooms of five residences in the San Francisco Bay area. Taxonomic classifications as well as the genome sequence and gene annotation of the isolates are described. As part of the "Built Environment Reference Genome" project, these isolates and associated genome data provide valuable resources for studying the microbiology of the built environment.

A Pseudomonas aeruginosa strain isolated from a contact lens-induced acute red eye (CLARE) is protease-deficient.

Science.gov (United States)

Estrellas, P S; Alionte, L G; Hobden, J A

2000-03-01

Pseudomonas aeruginosa proteases are thought to be important virulence factors in the pathogenesis of corneal disease. This study examined protease production from two strains of P. aeruginosa responsible for two very distinct clinical diseases: strain Paer1, isolated from a Contact Lens-induced Acute Red Eye (CLARE), and strain KEI 1025, isolated from a corneal ulcer. Strains were compared to a laboratory strain (ATCC 19660) known to produce severe keratitis in experimentally infected mice for protease production and for ocular virulence. Protease production was examined with colorimetric assays, gelatin zymography and western blots. Elastase A activity was quantitated with a staphylolytic assay. Ocular virulence was examined using a mouse scratch model of keratitis. In contrast to strains KEI 1025 or ATCC 19660, Paer1 was unable to produce enzymatically active elastase A, elastase, and protease IV. All three strains produced active alkaline protease. Strains KEI 1025 and ATCC 19660 produced a fulminant keratitis in mice whereas Paer1 produced a mild transient infection. Restoration of elastase activity in Paer1 via genetic complementation did not result in a virulent phenotype. Co-infection of mouse eyes with strains Paer1 and ATCC 19660 resulted in the eventual loss of Paer1 from corneal tissue. These studies suggest that P. aeruginosa elastase A and/or protease IV, but not alkaline protease or elastase, contribute to the ocular virulence of this organism.

Pseudomonas endophytica sp. nov., isolated from stem tissue of Solanum tuberosum L. in Spain.

Science.gov (United States)

Ramírez-Bahena, Martha-Helena; Cuesta, Maria José; Tejedor, Carmen; Igual, José Mariano; Fernández-Pascual, Mercedes; Peix, Álvaro

2015-07-01

A bacterial strain named BSTT44(T) was isolated in the course of a study of endophytic bacteria occurring in stems and roots of potato growing in a soil from Salamanca, Spain. The 16S rRNA gene sequence had 99.7% identity with respect to that of its closest relative, Pseudomonas psychrophila E-3T, and the next most closely related type strains were those of Pseudomonas fragi, with 99.6% similarity, Pseudomonas deceptionensis, with 99.2% similarity, and Pseudomonas lundensis, with 99.0% similarity; these results indicate that BSTT44(T) should be classified within the genus Pseudomonas. Analysis of the housekeeping genes rpoB, rpoD and gyrB confirmed its phylogenetic affiliation and showed identities lower than 92% in all cases with respect to the above-mentioned closest relatives. Cells of the strain bore one polar-subpolar flagellum. The respiratory quinone was Q-9.The major fatty acids were C16:0, C18:1ω7c and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The strain was oxidase-, catalase- and urease-positive and the arginine dihydrolase system was present, but tests for nitrate reduction, β-galactosidase production and aesculin hydrolysis were negative. It could grow at 35 °C and at pH 5-9.The DNA G+C content was 60.2 mol%. DNA-DNA hybridization results showed less than 48% relatedness with respect to the type strains of the four most closely related species. Therefore, the combined results of genotypic, phenotypic and chemotaxonomic analyses support the classification of strain BSTT44 into a novel species of the genus Pseudomonas, for which the name Pseudomonas endophytica sp. nov. is proposed. The type strain is BSTT44(T) ( = LMG 28456(T) = CECT 8691(T)).

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains

Directory of Open Access Journals (Sweden)

R.L. Arakaki

2013-12-01

Full Text Available Fungi have been recently recognized as organisms able to grow in presence of high salt concentration with halophilic and halotolerance properties and their ligninolytic enzyme complex have an unspecific action enabling their use to degradation of a number of xenobiotic compounds. In this work, both the effect of salt and polyols on growth of the basidiomycetes strains, on their ability to produce ligninolytic enzyme and diuron degradation were evaluated. Results showed that the presence of NaCl in the culture medium affected fungal specimens in different ways. Seven out of ten tested strains had growth inhibited by salt while Dacryopinax elegans SXS323, Polyporus sp MCA128 and Datronia stereoides MCA167 fungi exhibited higher biomass production in medium containing 0.5 and 0.6 mol.L-1 of NaCl, suggesting to be halotolerant. Polyols such as glycerol and mannitol added into the culture media improved the biomass and ligninases production by D. elegans but the fungus did not reveal consumption of these polyols from media. This fungus degraded diuron in medium control, in presence of NaCl as well as polyols, produced MnP, LiP and laccase.

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains.

Science.gov (United States)

Arakaki, R L; Monteiro, D A; Boscolo, M; Dasilva, R; Gomes, E

2013-12-01

Fungi have been recently recognized as organisms able to grow in presence of high salt concentration with halophilic and halotolerance properties and their ligninolytic enzyme complex have an unspecific action enabling their use to degradation of a number of xenobiotic compounds. In this work, both the effect of salt and polyols on growth of the basidiomycetes strains, on their ability to produce ligninolytic enzyme and diuron degradation were evaluated. Results showed that the presence of NaCl in the culture medium affected fungal specimens in different ways. Seven out of ten tested strains had growth inhibited by salt while Dacryopinax elegans SXS323, Polyporus sp MCA128 and Datronia stereoides MCA167 fungi exhibited higher biomass production in medium containing 0.5 and 0.6 mol.L(-1) of NaCl, suggesting to be halotolerant. Polyols such as glycerol and mannitol added into the culture media improved the biomass and ligninases production by D. elegans but the fungus did not reveal consumption of these polyols from media. This fungus degraded diuron in medium control, in presence of NaCl as well as polyols, produced MnP, LiP and laccase.

Antibacterial properties of Chinese herbal medicines against nosocomial antibiotic resistant strains of Pseudomonas aeruginosa in Taiwan.

Science.gov (United States)

Liu, Ching-Shen; Cham, Thau-Ming; Yang, Cheng-Hong; Chang, Hsueh-Wei; Chen, Chia-Hong; Chuang, Li-Yeh

2007-01-01

Pseudomonas aeruginosa is well-recognized as a nosocomial pathogen, which exhibits inherent drug resistance. In this study, the antibacterial activity of ethanol extracts of 58 Chinese herbal medicines used in Taiwan were tested against 89 nosocomial antibiotic resistant strains of Pseudomonas aeruginosa. The results gathered by the disc diffusion method showed that 26 out of the 58 herbal extracts exhibited antibacterial activity. Among the 26 herbal extracts, 10 extracts showed broad-spectrum antibacterial activities and were selected for further antibacterial property assay. The minimum inhibitory concentrations (MIC) of the active partition fractions ranged from 0.25 to 11.0 mg/L. The presence of flavonoid compounds in the active fractions of test herbal extracts was observed by the TLC-bioautography. The results from the time-kill assay revealed that most of the herbal extracts completely killed the test organisms within 4 hours. Exposure of the test strains to a sub-MIC level of the herbal extracts for 10 consecutive subcultures did not induce resistance to the active components. A combination of the active herbal fractions with antibiotics showed that one of the herbal medicines, the hexane fraction of Ramulus Cinnamomi, possessed a synergistic effect with tetracycline, gentamycin, and streptomycin. In conclusion, the tested Chinese medical herbs have the potential to be developed into natural antibiotics. This is the first evaluation for screening large amounts of medical plants against nosocomial antibiotic resistant bacteria in Taiwan.

Difference in Degradation Patterns on Inulin-type Fructans among Strains of Lactobacillus delbrueckii and Lactobacillus paracasei.

Science.gov (United States)

Tsujikawa, Yuji; Nomoto, Ryohei; Osawa, Ro

2013-01-01

Lactobacillus delbrueckii strains were assessed for their degradation patterns of various carbohydrates with specific reference to inulin-type fructans in comparison with those of Lactobacillus paracasei strains. Firstly, growth curves on glucose, fructose, sucrose and inulin-type fructans with increasing degrees of fructose polymerization (i.e., 1-kestose, fructo-oligosaccharides and inulin) of the strains were compared. L. paracasei DSM 20020 grew well on all these sugars, while the growth rates of the 4 L. delbrueckii strains were markedly higher on the fructans with a greater degree of polymerization than on fructose and sucrose. Secondly, sugar compositions of spent cultures of the strains of L. delbrueckii and L. paracasei grown in mMRS containing either the fructans or inulin were determined by thin layer chromatography, in which the spent cultures of L. paracasei DSM 20020 showed spots of short fructose and sucrose fractions, whereas those of the L. delbrueckii strains did not show such spots at all. These results suggest that, unlike the L. paracasei strains, the L. delbrueckii strains do not degrade the inulin-type fructans extracellularly, but transport the fructans capable of greater polymerization preferentially into their cells to be degraded intracellularly for their growth.

Evaluación de la actividad desulfurizadora de aislados nativos de Pseudomonas spp. en presencia de hidrocarburo Desulfurization activity evaluation of native strains of Pseudomonas spp. in the presence of hydrocarbon

Directory of Open Access Journals (Sweden)

Alméciga-Díaz Carlos Javier

2005-07-01

Full Text Available El principal inconveniente en la combustión de los hidrocarburos es la conversión del azufre y el nitrógeno a sus respectivos óxidos, los cuales participan en la formación de lluvia acida y deterioran el medio ambiente e infraestructuras. La remoción de azufre a partir de compuestos órgano-azufrados mediante el uso de microorganismos ha surgido como una alternativa frente al proceso catalítico de hidrodesulfurización (HDS. En el presente trabajo se evaluó la actividad desulfurizadora de veintitrés aislados nativos de Pseudomonas spp. sobre dibenzotiofeno (DBT, usando un sistema de fermentación con igual proporción de fase acuosa y orgánica (n-hexano en presencia de oleato de etanolamina. Los aislados 02,05 y 06 conservaron su viabilidad en este medio y presentaron una remoción de azufre entre 6,0 y 9,4%, generando los metabolitos DBT-sulfona, DBT-sulfóxido, 2-hidroxibifenilo (2-HBP y sulfato presentes en la ruta metabólica 4S. Con estos aislados se evaluó la actividad desulfurizadora sobre keroseno y se observó una remoción de azufre entre 19,9 y 62,6% y una disminución del poder calorífico entre 0,45 y 5,55%. Palabras clave: dibenzotiofeno, desulfurización, Pseudomonas spp., keroseno.The main difficulty with fossil fuel combustión lies in sulphur and nitrogen becoming converted to their respective oxides, forming part of the acid rain which deteriorates the environment and infrastructure. Removing sulphur from organo-sulfur compounds by using micro-organisms has become an alternative to hydrodesulphurisation (HDS. Twenty-three Pseudomonas spp. native strains' desulphurisation activity on dibenzothiophene (DBT was evaluated by using a fermentation system having equal proportions of aqueous and organic (n-hexane phases in the presence of ethanolamine oléate. The 02, 05 and 06 strains maintained their viability in this médium, presenting 6,0% to 9,4% sulphur removal, producing DBT-sulphone, DBT-sulphoxide, 2

Biosynthesis and regulation of cyclic lipopeptides in Pseudomonas fluorescens

NARCIS (Netherlands)

Bruijn, de I.

2009-01-01

Cyclic lipopeptides (CLPs) are surfactant and antibiotic metabolites produced by a variety of bacterial
genera. For the genus Pseudomonas, many structurally different CLPs have been identified. CLPs play an
important role in surface motility of Pseudomonas strains, but also in virulence

Characterization of a novel oxyfluorfen-degrading bacterial strain Chryseobacterium aquifrigidense and its biochemical degradation pathway.

Science.gov (United States)

Zhao, Huanhuan; Xu, Jun; Dong, Fengshou; Liu, Xingang; Wu, Yanbing; Wu, Xiaohu; Zheng, Yongquan

2016-08-01

Persistent use of the diphenyl ether herbicides oxyfluorfen may seriously increase the health risks and ecological safety problems. A newly bacterium R-21 isolated from active soil was able to degrade and utilize oxyfluorfen as the sole carbon source. R-21 was identified as Chryseobacterium aquifrigidense by morphology, physiobiochemical characteristics, and genetic analysis. Under the optimum cultural conditions (pH 6.9, temperature 33.4 °C, and inoculum size 0.2 g L(-1)), R-21 could degrade 92.1 % of oxyfluorfen at 50 mg L(-1) within 5 days. During oxyfluorfen degradation, six metabolites were detected and identified by atmospheric pressure gas chromatography coupled to quadrupole-time of flight mass spectrometry and ultra-performance liquid chromatography coupled to quadrupole-time of flight mass spectrometry, and a plausible degradation pathway was deduced. Strain R-21 is a promising potential in bioremediation of oxyfluorfen-contaminated environments.

Contribution of increased mutagenesis to the evolution of pollutants-degrading indigenous bacteria

Science.gov (United States)

Ilmjärv, Tanel; Naanuri, Eve; Kivisaar, Maia

2017-01-01

Bacteria can rapidly evolve mechanisms allowing them to use toxic environmental pollutants as a carbon source. In the current study we examined whether the survival and evolution of indigenous bacteria with the capacity to degrade organic pollutants could be connected with increased mutation frequency. The presence of constitutive and transient mutators was monitored among 53 pollutants-degrading indigenous bacterial strains. Only two strains expressed a moderate mutator phenotype and six were hypomutators, which implies that constitutively increased mutability has not been prevalent in the evolution of pollutants degrading bacteria. At the same time, a large proportion of the studied indigenous strains exhibited UV-irradiation-induced mutagenesis, indicating that these strains possess error-prone DNA polymerases which could elevate mutation frequency transiently under the conditions of DNA damage. A closer inspection of two Pseudomonas fluorescens strains PC20 and PC24 revealed that they harbour genes for ImuC (DnaE2) and more than one copy of genes for Pol V. Our results also revealed that availability of other nutrients in addition to aromatic pollutants in the growth environment of bacteria affects mutagenic effects of aromatic compounds. These results also implied that mutagenicity might be affected by a factor of how long bacteria have evolved to use a particular pollutant as a carbon source. PMID:28777807

Microbial surfactant mediated degradation of anthracene in aqueous phase by marine Bacillus licheniformis MTCC 5514

Directory of Open Access Journals (Sweden)

Sreethar Swaathy

2014-12-01

Full Text Available The present study emphasizes the biosurfactant mediated anthracene degradation by a marine alkaliphile Bacillus licheniformis (MTCC 5514. The isolate, MTCC 5514 degraded >95% of 300 ppm anthracene in an aqueous medium within 22 days and the degradation percentage reduced significantly when the concentration of anthracene increased to above 500 ppm. Naphthalene, naphthalene 2-methyl, phthalic acid and benzene acetic acid are the products of degradation identified based on thin layer chromatography, high performance liquid chromatography, gas chromatography and mass analyses. It has been observed that the degradation is initiated by the biosurfactant of the isolate for solubilization through micellation and then the alkali pH and intra/extra cellular degradative enzymes accomplish the degradation process. Encoding of genes responsible for biosurfactant production (licA3 as well as catabolic reactions (C23O made with suitable primers designed. The study concludes in situ production of biosurfactant mediates the degradation of anthracene by B. licheniformis.

Limnobacter spp. as newly detected phenol-degraders among Baltic Sea surface water bacteria characterised by comparative analysis of catabolic genes.

Science.gov (United States)

Vedler, Eve; Heinaru, Eeva; Jutkina, Jekaterina; Viggor, Signe; Koressaar, Triinu; Remm, Maido; Heinaru, Ain

2013-12-01

A set of phenol-degrading strains of a collection of bacteria isolated from Baltic Sea surface water was screened for the presence of two key catabolic genes coding for phenol hydroxylases and catechol 2,3-dioxygenases. The multicomponent phenol hydroxylase (LmPH) gene was detected in 70 out of 92 strains studied, and 41 strains among these LmPH(+) phenol-degraders were found to exhibit catechol 2,3-dioxygenase (C23O) activity. Comparative phylogenetic analyses of LmPH and C23O sequences from 56 representative strains were performed. The studied strains were mostly affiliated to the genera Pseudomonas and Acinetobacter. However, the study also widened the range of phenol-degraders by including the genus Limnobacter. Furthermore, using a next generation sequencing approach, the LmPH genes of Limnobacter strains were found to be the most prevalent ones in the microbial community of the Baltic Sea surface water. Four different Limnobacter strains having almost identical 16S rRNA gene sequences (99%) and similar physiological properties formed separate phylogenetic clusters of LmPH and C23O genes in the respective phylogenetic trees. Copyright © 2013 Elsevier GmbH. All rights reserved.

Conservation of the response regulator gene gacA in Pseudomonas species

NARCIS (Netherlands)

Souza, J.T.; Mazzola, M.; Raaijmakers, J.M.

2003-01-01

The response regulator gene gacA influences the production of several secondary metabolites in both pathogenic and beneficial Pseudomonas spp. In this study, we developed primers and a probe for the gacA gene of Pseudomonas species and sequenced a 425 bp fragment of gacA from ten Pseudomonas strains

Metabolic engineering of Pseudomonas fluorescens for the production of vanillin from ferulic acid.

Science.gov (United States)

Di Gioia, Diana; Luziatelli, Francesca; Negroni, Andrea; Ficca, Anna Grazia; Fava, Fabio; Ruzzi, Maurizio

2011-12-20

Vanillin is one of the most important flavors in the food industry and there is great interest in its production through biotechnological processes starting from natural substrates such as ferulic acid. Among bacteria, recombinant Escherichia coli strains are the most efficient vanillin producers, whereas Pseudomonas spp. strains, although possessing a broader metabolic versatility, rapidly metabolize various phenolic compounds including vanillin. In order to develop a robust Pseudomonas strain that can produce vanillin in high yields and at high productivity, the vanillin dehydrogenase (vdh)-encoding gene of Pseudomonas fluorescens BF13 strain was inactivated via targeted mutagenesis. The results demonstrated that engineered derivatives of strain BF13 accumulate vanillin if inactivation of vdh is associated with concurrent expression of structural genes for feruloyl-CoA synthetase (fcs) and hydratase/aldolase (ech) from a low-copy plasmid. The conversion of ferulic acid to vanillin was enhanced by optimization of growth conditions, growth phase and parameters of the bioconversion process. The developed strain produced up to 8.41 mM vanillin, which is the highest final titer of vanillin produced by a Pseudomonas strain to date and opens new perspectives in the use of bacterial biocatalysts for biotechnological production of vanillin from agro-industrial wastes which contain ferulic acid. Copyright © 2011 Elsevier B.V. All rights reserved.

Production of xylan-degrading enzymes by a Trichoderma harzianum strain

Directory of Open Access Journals (Sweden)

Cacais André O.Guerreiro

2001-01-01

Full Text Available Trichoderma harzianum strain 4 produced extracellular xylan-degrading enzymes, namely beta-xylanase, beta-xylosidase and alpha-arabinofuranosidase, when grown in liquid medium cultures containing oat spelt xylan as inducer. Cellulase activity was not detected. The pattern of xylan-degrading enzymes induction was influenced by the form of xylan present in the medium. They were detected in different incubation periods. Electrophoretic separation of the proteins from liquid culture filtrates by SDS-PAGE showed a variety of bands with high and low molecular weights.

Complementary Mechanisms for Degradation of Inulin-Type Fructans and Arabinoxylan Oligosaccharides among Bifidobacterial Strains Suggest Bacterial Cooperation.

Science.gov (United States)

Rivière, Audrey; Selak, Marija; Geirnaert, Annelies; Van den Abbeele, Pieter; De Vuyst, Luc

2018-05-01

Inulin-type fructans (ITF) and arabinoxylan oligosaccharides (AXOS) are broken down to different extents by various bifidobacterial strains present in the human colon. To date, phenotypic heterogeneity in the consumption of these complex oligosaccharides at the strain level remains poorly studied. To examine mechanistic variations in ITF and AXOS constituent preferences present in one individual, ITF and AXOS consumption by bifidobacterial strains isolated from the simulator of the human intestinal microbial ecosystem (SHIME) after inoculation with feces from one healthy individual was investigated. Among the 18 strains identified, four species-independent clusters displaying different ITF and AXOS degradation mechanisms and preferences were found. Bifidobacterium bifidum B46 showed limited growth on all substrates, whereas B. longum B24 and B. longum B18 could grow better on short-chain-length fractions of fructooligosaccharides (FOS) than on fructose. B. longum B24 could cleave arabinose substituents of AXOS extracellularly, without using the AXOS-derived xylose backbones, whereas B. longum B18 was able to consume oligosaccharides (up to xylotetraose) preferentially and consumed AXOS to a limited extent. B. adolescentis B72 degraded all fractions of FOS simultaneously, partially degraded inulin, and could use xylose backbones longer than xylotetraose extracellularly. The strain-specific degradation mechanisms were suggested to be complementary and indicated resource partitioning. Specialization in the degradation of complex carbohydrates by bifidobacteria present on the individual level could have in vivo implications for the successful implementation of ITF and AXOS, aiming at bifidogenic and/or butyrogenic effects. Finally, this work shows the importance of taking microbial strain-level differences into account in gut microbiota research. IMPORTANCE It is well known that bifidobacteria degrade undigestible complex polysaccharides, such as ITF and AXOS, in the

Naphthalene and Naphthoquinone: Distributions and Human Exposure in the Los Angeles Basin

Science.gov (United States)

Lu, R.; Wu, J.; Turco, R.; Winer, A. M.; Atkinson, R.; Paulson, S.; Arey, J.; Lurmann, F.

2003-12-01

Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons (PAHs). Naphthalene is found primarily in the gas-phase and has been detected in both outdoor and indoor samples. Evaporation from naphthalene-containing products (including gasoline), and during refining operations, are important sources of naphthalene in air. Naphthalene is also emitted during the combustion of fossil fuels and wood, and is a component of vehicle exhaust. Exposure to high concentrations of naphthalene can damage or destroy red blood cells, causing hemolytic anemia. If inhaled over a long period of time, naphthalene may cause kidney and liver damage, skin allergy and dermatitis, cataracts and retinal damage, as well as attack the central nervous system. Naphthalene has been found to cause cancer as a result of inhalation in animal tests. Naphthoquinones are photooxidation products of naphthalene and the potential health effects of exposure to these quinones are a current focus of research. We are developing and applying models that can be used to assess human exposure to naphthalene and its photooxidation products in major air basins such as California South Coast Air Basin (SoCAB). The work utilizes the Surface Meteorology and Ozone Generation (SMOG) airshed model, and the REgional Human EXposure (REHEX) model, including an analysis of individual exposure. We will present and discuss simulations of basin-wide distributions of, and human exposures to, naphthalene and naphthoquinone, with emphasis on the uncertainties in these estimates of atmospheric concentrations and human exposure. Regional modeling of pollutant sources and exposures can lead to cost-effective and optimally health-protective emission control strategies.

Biodegradation of hexavalent chromium (Cr+6) in wastewater using Pseudomonas sp. and Bacillus sp. bacterial strains

Energy Technology Data Exchange (ETDEWEB)

Qasim, Muhammad [Department of Chemical Engineering, American University of Sharjah (United Arab Emirates)

2013-07-01

The recovery of toxic metal compounds is a deep concern in all industries. Hexavalent chromium is particularly worrying because of its toxic influence on human health. In this paper, biodegradation of hexavalent chromium (Cr+6) present in wastewater has been studied using two different bacterial strains; Pseudomonas sp. and Bacillus sp. A chemostat (with and without recycle of cells) with 10 L liquid culture volume was used to study the substrate and the biomass cell concentrations with time. Also, the degree of substrate conversion was studied by the varying the dilution rate as an independent parameter. The dilution rate (ratio of feed flow rate to the culture volume) was varied by varying the feed volumetric rate from 110-170 mL/h for inlet hexavalent chromium concentrations of 70 mg/dm3. The results show that a chemostat with recycle gives a better performance in terms of substrate conversion than a chemostat without a recycle. Moreover, the degree of substrate conversion decreases as the dilution rate is increased. Also, Bacillus sp. was found to give higher conversions compared to pseudomonas sp.

Pulsed-field gel electrophoresis of multidrug-resistant and -sensitive strains of Pseudomonas aeruginosa from a Malaysian hospital.

Science.gov (United States)

Thong, Kwai Lin; Lai, Kin Seng; Ganeswrie, R; Puthucheary, S D

2004-10-01

Over a period of 6 months from January to June 2002, an unusual increase in the isolation of highly resistant Pseudomonas aeruginosa strains was observed in the various wards and intensive care units of a large general hospital in Johor Bahru, Malaysia. An equal number of multidrug resistant (MDR) and drug-susceptible strains were collected randomly from swabs, respiratory specimens, urine, blood, cerebral spinal fluid, and central venous catheters to determine the clonality and genetic variation of the strains. Macrorestriction analysis by pulsed-field gel electrophoresis showed that the 19 MDR strains were genetically very homogenous; the majority showed the dominant profile S1 (n = 10), the rest very closely related profiles S1a (n = 1), S2 (n = 4), and S2a (n = 3), indicating the endemicity of these strains. In contrast, the 19 drug-sensitive strains isolated during the same time period were genetically more diverse, showing 17 pulsed-field profiles (F = 0.50-1.00), and probably derived from the patients themselves. The presence of the MDR clone poses serious therapeutic problems as it may become endemic in the hospital and give rise to future clonal outbreaks. There is also the potential for wider geographical spread.

Activity and three-dimensional distribution of toluene-degrading Pseudomonas putida in a multispecies biofilm assessed by quantitative in situ hybridization and scanning confocal laser microscopy

DEFF Research Database (Denmark)

Møller, Søren; Pedersen, Anne Rathmann; Poulsen, L.K.

1996-01-01

As a representative member of the toluene-degrading population in a biofilter for waste gas treatment, Pseudomonas putida was investigated with a 16S rRNA targeting probe, The three-dimensional distribution of P. putida was visualized in the biofilm matrix by scanning confocal laser microscopy...

Isolation and characterization of a furfural-degrading bacterium Bacillus cereus sp. strain DS1.

Science.gov (United States)

Zheng, Dan; Bao, Jianguo; Lu, Jueming; Gao, Chunlei

2015-02-01

Furfural was found to be the main organic pollutant in the wastewater coming from the Diosgenin factory. This substance is derived from acidic pentosan in Dioscorea zingiberensis and is also found in a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. It is regarded as a toxicant and an inhibitor to the growth of microorganism in both sewage disposal and biological fermentation. A furfural-degrading strain (DS1) was isolated from activated sludge of wastewater treatment plant in a diosgenin factory by continuous enrichment culture. The strain was identified as Bacillus cereus based on morphological, physiological tests, as well as on 16S rDNA sequence and Biolog analyses. The capacity of this strain to grow on a mineral salt medium, utilizing furfural as the sole carbon and energy source to degrade furfural, was investigated in this study. Under the condition of pH 9.0, temperature 35 °C, with rotating speed of 150 rpm, and an inoculum of 6 %, the strain showed that the furfural degradation capacity reaches 35 % in 7 days, as measured by high-performance liquid chromatography. The addition of inorganic carbon sources could bring down the biodegradation efficiency of the furfural. The strain DS1 showed better furfural removal capacity, as compared to other inorganic carbon sources in the media. Furthermore, a furfural concentration of as high as 4,000 mg L(-1) was tolerated by the culture. The capacity to degrade furfural was demonstrated for the first time by using the genus B. cereus. This study suggests the possible application in biodegradation strategies.

Transformation of pWWO in Rhizobium leguminosarum DPT to Engineer Toluene Degrading Ability for Rhizoremediation

OpenAIRE

Goel, Garima; Pandey, Piyush; Sood, Anchal; Bisht, Sandeep; Maheshwari, D. K.; Sharma, G. D.

2011-01-01

Rhizoremediation of organic xenobiotics is based on interactions between plants and their associated micro-organisms. The present work was designed to engineer a bacterial system having toluene degradation ability along with plant growth promoting characteristics for effective rhizoremediation. pWWO harboring the genes responsible for toluene breakdown was isolated from Pseudomonas putida MTCC 979 and successfully transformed in Rhizobium DPT. This resulted in a bacterial strain (DPTT) which ...

Pseudomonas syringae evades host immunity by degrading flagellin monomers with alkaline protease AprA.

Science.gov (United States)

Pel, Michiel J C; van Dijken, Anja J H; Bardoel, Bart W; Seidl, Michael F; van der Ent, Sjoerd; van Strijp, Jos A G; Pieterse, Corné M J

2014-07-01

Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant pathogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantly less virulent on both tomato and Arabidopsis thaliana. Moreover, infiltration of A. thaliana Col-0 leaves with DC3000 ΔaprA evoked a significantly higher level of expression of the defense-related genes FRK1 and PR-1 than did wild-type DC3000. In the flagellin receptor mutant fls2, pathogen virulence and defense-related gene activation did not differ between DC3000 and DC3000 ΔaprA. Together, these results suggest that AprA of DC3000 is important for evasion of recognition by the FLS2 receptor, allowing wild-type DC3000 to be more virulent on its host plant than AprA-deficient DC3000 ΔaprA. To provide further evidence for the role of DC3000 AprA in host immune evasion, we overexpressed the AprA inhibitory peptide AprI of DC3000 in A. thaliana to counteract the immune evasive capacity of DC3000 AprA. Ectopic expression of aprI in A. thaliana resulted in an enhanced level of resistance against wild-type DC3000, while the already elevated level of resistance against DC3000 ΔaprA remained unchanged. Together, these results indicate that evasion of host immunity by the alkaline protease AprA is important for full virulence of strain DC3000 and likely acts by preventing flagellin monomers from being recognized by its cognate immune receptor.

Kinetic Evaluation of Naphthalene Removal using Acid - Modified ...

African Journals Online (AJOL)

Kinetic evaluation of naphthalene onto acid – modified and unmodified bentonite clay mineral was investigated by means of the effects of concentration, contact time and pH. The amount of naphthalene adsorbed was determined spectrophotometrically. The optimum pH value and equilibrium contact time for the adsorption ...

Utilizing dendritic scaffold for feasible formation of naphthalene ...

Indian Academy of Sciences (India)

the effect of dendritic scaffolds on the feasibility of naphthalene excimer formation has not been reported in the literature. Here, we report synthesis and photophysical study of naphthalene functionalized zero and first genera- tion PAMAM dendrimers in order to understand the mechanism of excimer formation in the system.

Effect of Aspergillus versicolor strain JASS1 on low density polyethylene degradation

Science.gov (United States)

Gajendiran, A.; Subramani, S.; Abraham, J.

2017-11-01

Low density polyethylene (LDPE) waste disposal remains one of the major environmental concerns faced by the world today. In past decades, major focus has been given to enhance the biodegradation of LDPE by microbial species. In this present study, Aspergillus versicolor with the ability to degrade LDPE was isolated from municipal landfill area using enrichment technique. Based on 18S rRNA gene sequencing confirmed its identity as Aspergillus versicolor. The biodegradation study was carried out for 90 d in M1 medium. The degradation behaviour of LDPE films by Aspergillus versicolor strain JASS1 were confirmed by weight loss, CO2 evolution, Scanning electron microscopy (SEM) analysis, Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) technique. From current investigation, it can be concluded that our isolated strain JASS1 had the potential to degrade LDPE films and it can be useful in solving the problem caused by polyethylene in the environment.

Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

Science.gov (United States)

Gargouri, Boutheina; Mhiri, Najla; Karray, Fatma; Aloui, Fathi; Sayadi, Sami

2015-01-01

Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons. PMID:26339653

Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

Directory of Open Access Journals (Sweden)

Boutheina Gargouri

2015-01-01

Full Text Available Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons.

Multi-functionalized naphthalene complexes for hydrogen storage

International Nuclear Information System (INIS)

Kalamse, Vijayanand; Wadnerkar, Nitin; Chaudhari, Ajay

2013-01-01

A density functional study of hydrogen uptake capacity of multi-functionalized naphthalene with Ti and Li metal atom has been carried out. It is observed that, the naphthalene functionalized with two Ti atoms can interact with total eight hydrogen molecules in which each Ti metal atom interacts with four hydrogen molecules. Naphthalene decorated with two Li atoms can interact with total three H 2 molecules only. First ( 19 Li) and second ( 20 Li) Li atom can interact with only one and two hydrogen molecule respectively. It is observed that, hydrogen molecules bind strongly to the C 10 H 8 Ti 2 complex than C 10 H 8 Li 2 complex. The gravimetric hydrogen uptake capacity of C 10 H 8 Ti 2 and C 10 H 8 Li 2 complex is found to be 6.72 and 3.73 wt% respectively. Moreover, after functionalizing naphthalene with four Li atoms, the uptake capacity is increased to 7.20 wt %. However, the thermochemistry result favors to Ti functionalized naphthalene complex (C 10 H 8 Ti 2 ) for hydrogen storage over Li functionalized naphthalene (both C 10 H 8 Li 2 and C 10 H 8 Li 4 ) complexes. Atom-centered density matrix propagation (ADMP) molecular dynamics simulations have been performed which showed that C 10 H 8 Li 2 and C 10 H 8 Li 4 complex cannot bind single hydrogen molecule at room temperature whereas C 10 H 8 Ti 2 can bind five hydrogen molecules. -- Highlights: ► The gravimetric H 2 uptake capacity of C 10 H 8 Ti 2 complex is 6.72 wt%. ► Uptake capacity of C 10 H 8 Li 2 and C 10 H 8 Li 4 complex is 3.73 and 7.20 wt% respectively. ► C 10 H 8 Ti is more promising material for hydrogen adsorption. ► C 10 H 8 Ti 2 can bind five hydrogen molecules as shown by ADMP-MD results.

Alkane and crude oil degrading bacteria from the petroliferous soil of India

International Nuclear Information System (INIS)

Roy, I.; Mishra, A.K.; Ray, A.K.

1991-01-01

It has been estimated that approximately 0.5 percent of transported crude oil finds its way into seawater, largely through accidental spills and discharge of ballast and wash water from oil tankers. Some microorganisms are well known for their ability to degrade a variety of hydrocarbons present in crude oil. Oil spills at sea or on land have demonstrated the hydrocarbon-degrading potential of these organisms. Under laboratory conditions, nitrogen may be supplied in soluble form (inorganic salts of ammonia or nitrate of urea). Since most natural aquatic environments are deficient in utilizable forms of nitrogen, it is necessary to add the same exogeneously, but because of rapid dilution the added source of nitrogen does not remain effective. The need for nitrogen supplements may be overcome by appropriate choice of microbes with the genetic capacity to fix molecular nitrogen. In this paper the authors are reporting the isolation of a strain of Pseudomonas stutzeri from the petroliferous soil of India. This strain has the capacity to degrade alkane and crude oil and to fix nitrogen

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

Science.gov (United States)

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

2013-05-01

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

Effect of Naphthalene and Salicylate Analogues on the Bioluminescence of Bioreporter Pseudomonas Fluorescens HK44.

Czech Academy of Sciences Publication Activity Database

Trögl, Josef; Kuncová, Gabriela; Kubicová, L.; Pařík, P.; Hálová, Jaroslava; Demnerová, K.; Ripp, S.; Sayler, G. S.

2007-01-01

Roč. 52, 1 (2007) , s. 3-14 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA104/05/2637; GA ČR(CZ) GA203/06/1244 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40320502 Keywords : pseudomonas fluorescens HK44 * bioluminescence * bioluminescence Subject RIV: CE - Biochemistry Impact factor: 0.989, year: 2007

Complexity of resistance mechanisms to imipenem in intensive care unit strains of Pseudomonas aeruginosa.

Science.gov (United States)

Fournier, Damien; Richardot, Charlotte; Müller, Emeline; Robert-Nicoud, Marjorie; Llanes, Catherine; Plésiat, Patrick; Jeannot, Katy

2013-08-01

Pseudomonas aeruginosa can become resistant to carbapenems by both intrinsic (mutation-driven) and transferable (β-lactamase-based) mechanisms. Knowledge of the prevalence of these various mechanisms is important in intensive care units (ICUs) in order to define optimal prevention and therapeutic strategies. A total of 109 imipenem-non-susceptible (MIC >4 mg/L) strains of P. aeruginosa were collected in June 2010 from the ICUs of 26 French public hospitals. Their resistance mechanisms were characterized by phenotypic, enzymatic, western blotting and molecular methods. Single or associated imipenem resistance mechanisms were identified among the 109 strains. Seven isolates (6.4%) were found to produce a metallo-β-lactamase (one VIM-1, four VIM-2, one VIM-4 and one IMP-29). Porin OprD was lost in 94 (86.2%) strains as a result of mutations or gene disruption by various insertion sequences (ISPa1635, ISPa1328, IS911, ISPs1, IS51, IS222 and ISPa41). Thirteen other strains were shown to be regulatory mutants in which down-regulation of oprD was coupled with overexpressed efflux pumps CzcCBA (n = 1), MexXY (n = 9) and MexEF-OprN (n = 3). The lack of OprD was due to disruption of the oprD promoter by ISPsy2 in one strain and alteration of the porin signal sequence in another. Imipenem resistance in ICU P. aeruginosa strains may result from multiple mechanisms involving metallo-β-lactamase gene acquisition and genetic events (mutations and ISs) inactivating oprD, turning down its expression while increasing efflux activities or preventing insertion of porin OprD in the outer membrane. This diversity of mechanisms allows P. aeruginosa, more than any other nosocomial pathogen, to rapidly adapt to carbapenems in ICUs.

Reclassification of Serpens flexibilis Hespell 1977 as Pseudomonas flexibilis comb. nov., with Pseudomonas tuomuerensis Xin et al. 2009 as a later heterotypic synonym.

Science.gov (United States)

Shin, Su-Kyoung; Hwang, Chung Yeon; Cho, Yong-Joon; Yi, Hana

2015-12-01

Serpens flexibilis was proposed in 1977 and approved in 1980 without the 16S rRNA gene sequence information. The sequence of S. flexibilis became available in 2010, after the publication of Pseudomonas tuomuerensis in 2009. Our preliminary phylogenetic analyses indicated that these two strains share high sequence similarity and therefore showed strong potential to be united into a single species. To clarify the taxonomic status of the two species, a polyphasic taxonomy study was conducted including whole genome sequencing. The value of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between the genome sequences of S. flexibilis ATCC 29606(T) and P. tuomuerensis JCM 14085(T) were 98.1% and 89.0%, respectively. The phenotypic and chemotaxonomic properties including enzymatic activities, substrate utilization profiles, and fatty acids, supported that the two taxa have no pronounced difference and should thus constitute a single species. Therefore, we propose to transfer Serpens flexibilis Hespell 1977 to the genus Pseudomonas as Pseudomonas flexibilis comb. nov. (type strain=ATCC 29606(T)), with Pseudomonas tuomuerensis Xin et al. 2009 as a later heterotypic synonym of Pseudomonas flexibilis. Copyright © 2015 Elsevier GmbH. All rights reserved.

Inhibitory and Toxic Effects of Volatiles Emitted by Strains of Pseudomonas and Serratia on Growth and Survival of Selected Microorganisms, Caenorhabditis elegans, and Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Alexandra A. Popova

2014-01-01

Full Text Available In previous research, volatile organic compounds (VOCs emitted by various bacteria into the chemosphere were suggested to play a significant role in the antagonistic interactions between microorganisms occupying the same ecological niche and between bacteria and target eukaryotes. Moreover, a number of volatiles released by bacteria were reported to suppress quorum-sensing cell-to-cell communication in bacteria, and to stimulate plant growth. Here, volatiles produced by Pseudomonas and Serratia strains isolated mainly from the soil or rhizosphere exhibited bacteriostatic action on phytopathogenic Agrobacterium tumefaciens and fungi and demonstrated a killing effect on cyanobacteria, flies (Drosophila melanogaster, and nematodes (Caenorhabditis elegans. VOCs emitted by the rhizospheric Pseudomonas chlororaphis strain 449 and by Serratia proteamaculans strain 94 isolated from spoiled meat were identified using gas chromatography-mass spectrometry analysis, and the effects of the main headspace compounds—ketones (2-nonanone, 2-heptanone, 2-undecanone and dimethyl disulfide—were inhibitory toward the tested microorganisms, nematodes, and flies. The data confirmed the role of bacterial volatiles as important compounds involved in interactions between organisms under natural ecological conditions.

Molecular characterization of Lactobacillus plantarum DMDL 9010, a strain with efficient nitrite degradation capacity.

Science.gov (United States)

Fei, Yong-tao; Liu, Dong-mei; Luo, Tong-hui; Chen, Gu; Wu, Hui; Li, Li; Yu, Yi-gang

2014-01-01

Nitrites commonly found in food, especially in fermented vegetables, are potential carcinogens. Therefore, limiting nitrites in food is critically important for food safety. A Lactobacillus strain (Lactobacillus sp. DMDL 9010) was previously isolated from fermented vegetables by our group, and is not yet fully characterized. A number of phenotypical and genotypical approaches were employed to characterize Lactobacillus sp. DMDL 9010. Its nitrite degradation capacity was compared with four other Lactobacillus strains, including Lactobacillus casei subsp. rhamnosus 719, Lactobacillus delbrueckii subsp. bulgaricu 1.83, Streptococcus thermophilus 1.204, and lactobacillus plantarum 8140, on MRS medium. Compared to these four Lactobacillus strains, Lactobacillus sp. DMDL 9010 had a significantly higher nitrite degradation capacity (PLactobacillus sp. DMDL 9010 was identified as either Lactobacillus plantarum or Lactobacillus pentosus. To further identify this strain, the flanking regions (922 bp and 806 bp upstream and downstream, respectively) of the L-lactate dehydrogenase 1 (L-ldh1) gene were amplified and sequenced. Lactobacillus sp. DMDL 9010 had 98.92 and 76.98% sequence identity in the upstream region with L. plantarum WCFS1 and L. pentosus IG1, respectively, suggesting that Lactobacillu sp. DMDL 9010 is an L. plantarum strain. It was therefore named L. plantarum DMDL 9010. Our study provides a platform for genetic engineering of L. plantarum DMDL 9010, in order to further improve its nitrite degradation capacity.

Biodegradation of low and high molecular weight hydrocarbons in petroleum refinery wastewater by a thermophilic bacterial consortium.

Science.gov (United States)

Pugazhendi, Arulazhagan; Abbad Wazin, Hadeel; Qari, Huda; Basahi, Jalal Mohammad Al-Badry; Godon, Jean Jacques; Dhavamani, Jeyakumar

2017-10-01

Clean-up of contaminated wastewater remains to be a major challenge in petroleum refinery. Here, we describe the capacity of a bacterial consortium enriched from crude oil drilling site in Al-Khobar, Saudi Arabia, to utilize polycyclic aromatic hydrocarbons (PAHs) as sole carbon source at 60°C. The consortium reduced low molecular weight (LMW; naphthalene, phenanthrene, fluorene and anthracene) and high molecular weight (HMW; pyrene, benzo(e)pyrene and benzo(k)fluoranthene) PAH loads of up to 1.5 g/L with removal efficiencies of 90% and 80% within 10 days. PAH biodegradation was verified by the presence of PAH metabolites and evolution of carbon dioxide (90 ± 3%). Biodegradation led to a reduction of the surface tension to 34 ± 1 mN/m thus suggesting biosurfactant production by the consortium. Phylogenetic analysis of the consortium revealed the presence of the thermophilic PAH degrader Pseudomonas aeruginosa strain CEES1 (KU664514) and Bacillus thermosaudia (KU664515) strain CEES2. The consortium was further found to treat petroleum wastewater in continuous stirred tank reactor with 96 ± 2% chemical oxygen demand removal and complete PAH degradation in 24 days.

Degradation of phenanthrene and pyrene using genetically engineered dioxygenase producing Pseudomonas putida in soil

Directory of Open Access Journals (Sweden)

Mardani Gashtasb

2016-01-01

Full Text Available Bioremediation use to promote degradation and/or removal of contaminants into nonhazardous or less-hazardous substances from the environment using microbial metabolic ability. Pseudomonas spp. is one of saprotrophic soil bacterium and can be used for biodegradation of polycyclic aromatic hydrocarbons (PAHs but this activity in most species is weak. Phenanthrene and pyrene could associate with a risk of human cancer development in exposed individuals. The aim of the present study was application of genetically engineered P. putida that produce dioxygenase for degradation of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC method. The nahH gene that encoded catechol 2,3-dioxygenase (C23O was cloned into pUC18 and pUC18-nahH recombinant vector was generated and transformed into wild P. putida, successfully. The genetically modified and wild types of P. putida were inoculated in soil and pilot plan was prepared. Finally, degradation of phenanthrene and pyrene by this bacterium in spiked soil were evaluated using HPLC measurement technique. The results were showed elimination of these PAH compounds in spiked soil by engineered P. putida comparing to dishes containing natural soil with normal microbial flora and inoculated autoclaved soil by wild type of P. putida were statistically significant (p0.05 but it was few impact on this process (more than 2%. Additional and verification tests including catalase, oxidase and PCR on isolated bacteria from spiked soil were indicated that engineered P. putida was alive and functional as well as it can affect on phenanthrene and pyrene degradation via nahH gene producing. These findings indicated that genetically engineered P. putida generated in this work via producing C23O enzyme can useful and practical for biodegradation of phenanthrene and pyrene as well as petroleum compounds in polluted environments.

Phenazine–naphthalene-1,5-diamine–water (1/1/2

Directory of Open Access Journals (Sweden)

Maria Gdaniec

2009-12-01

Full Text Available The asymmetric unit of the title compound, C12H8N2·C10H10N2·2H2O, contains one half-molecule of phenazine, one half-molecule of naphthalene-1,5-diamine and one water molecule. The phenazine and naphthalene-1,5-diamine molecules are located on inversion centers. The water molecules serve as bridges between the naphthalene-1,5-diamine molecules and also between the naphthalene-1,5-diamine and phenazine molecules. The naphthalene-1,5-diamine and water molecules are connected via N—H...O and O—H...N hydrogen bonds, forming a T4(2 motif. They are arranged into a two-dimensional polymeric structure parallel to (10overline{1} in which the water molecule is a single donor and a double acceptor, whereas the amino group is a double donor and a single acceptor in the hydrogen bonding. These two-dimensional assemblies alternate with the layers of phenazine molecules arranged into a herringbone motif. Each phenazine molecule is hydrogen bonded to two water molecules and thus a three-dimensional framework of hydrogen-bonded molecules is generated.

Detection of Quorum Sensing Activity in the Multidrug-Resistant Clinical Isolate Pseudomonas aeruginosa Strain GB11

Directory of Open Access Journals (Sweden)

Huey Jia Cheng

2014-07-01

Full Text Available A multidrug-resistant clinical bacteria strain GB11 was isolated from a wound swab on the leg of a patient. Identity of stain GB11 as Pseudomonas aeruginosa was validated by using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS. Detection of the production of signaling molecules, N-acylhomoserine lactones (AHLs, was conducted using three different bacterial biosensors. A total of four different AHLs were found to be produced by strain GB11, namely N-butyryl homoserine lactone (C4-HSL, N-hexanoylhomoserine lactone (C6-HSL, N-octanoyl homoserine lactone (C8-HSL and N-3-oxo-dodecanoylhomoserine lactone (3-oxo-C12-HSL using high resolution liquid chromatography tandem mass spectrometry (LC-MS/MS. Of these detected AHLs, 3-oxo-C12-HSL was found to be the most abundant AHL produced by P. aeruginosa GB11.

Microbial degradation of phosmet on blueberry fruit and in aqueous systems by indigenous bacterial flora on lowbush blueberries (Vaccinium angustifolium).

Science.gov (United States)

Crowe, K M; Bushway, A A; Bushway, R J; Davis-Dentici, K

2007-10-01

Phosmet-adapted bacteria isolated from lowbush blueberries (Vaccinium angustifolium) were evaluated for their ability to degrade phosmet on blueberry fruit and in minimal salt solutions. Microbial metabolism of phosmet by isolates of Enterobacter agglomerans and Pseudomonas fluorescens resulted in significant reductions (P blueberries and in minimal salt solutions. Thus, the role of adapted strains of E. agglomerans and P. fluorescens in degrading phosmet on blueberries represents an extensive plant-microorganism relationship, which is essential to determination of phosmet persistence under pre- and postharvest conditions.

Isolation and Characterization of Polyacrylamide-Degrading Bacteria from Dewatered Sludge

Directory of Open Access Journals (Sweden)

Feng Yu

2015-04-01

Full Text Available Polyacrylamide (PAM is a water-soluble polymer that is widely used as a flocculant in sewage treatment. The accumulation of PAM affects the formation of dewatered sludge and potentially produces hazardous monomers. In the present study, the bacterial strain HI47 was isolated from dewatered sludge. This strain could metabolize PAM as its sole nutrient source and was subsequently identified as Pseudomonas putida. The efficiency of PAM degradation was 31.1% in 7 days and exceeded 45% under optimum culture condition (pH 7.2, 39 °C and 100 rpm. The addition of yeast extract and glucose improved the bacterial growth and PAM degradation. The degraded PAM samples were analyzed by gel-filtration chromatography, Fourier transform infrared and high-performance liquid chromatography. The results showed that high-molecular-weight PAM was partly cleaved to small molecular oligomer derivatives and part of the amide groups of PAM had been converted to carboxyl groups. The biodegradation did not accumulate acrylamide monomers. Based on the SDS-PAGE and N-terminal sequencing results, the PAM amide groups were converted into carboxyl groups by a PAM-induced extracellular enzyme from the aliphatic amidase family.

Accumulation of a Polyhydroxyalkanoate Containing Primarily 3-Hydroxydecanoate from Simple Carbohydrate Substrates by Pseudomonas sp. Strain NCIMB 40135.

Science.gov (United States)

Haywood, G W; Anderson, A J; Ewing, D F; Dawes, E A

1990-11-01

A number of Pseudomonas species have been identified which accumulate a polyhydroxyalkanoate containing mainly 3-hydroxydecanoate monomers from sodium gluconate as the sole carbon source. One of these, Pseudomonas sp. strain NCIMB 40135, was further investigated and shown to accumulate such a polyhydroxyalkanoate from a wide range of carbon sources (C(2) to C(6)); however, when supplied with octanoic acid it produced a polyhydroxyalkanoate containing mainly 3-hydroxyoctanoate monomers. Polymer synthesis occurred in batch culture after cessation of growth due to exhaustion of nitrogen. In continuous culture under nitrogen limitation up to 16.9% (wt/wt) polyhydroxyalkanoate was synthesized from glucose as the carbon source. The monomer units are mainly of the R-(-) configuration. Nuclear magnetic resonance studies confirmed the composition of the polymer. Differential scanning calorimetry suggested that the solvent-extracted polymer contained a significant proportion of crystalline material. The weight-average molecular weight of the polymer from glucose-grown cells was 143,000.

Biosurfactant production by Pseudomonas sp. and its role in aqueous phase partitioning and biodegradation of chlorpyrifos.

Science.gov (United States)

Singh, P B; Sharma, S; Saini, H S; Chadha, B S

2009-09-01

To study the effect of biosurfactant on aqueous phase solubility and biodegradation of chlorpyrifos. A Pseudomonas sp. (ChlD), isolated from agricultural soil by enrichment culture technique in the presence of chlorpyrifos, was capable of producing biosurfactant (rhamnolipids) and degrading chlorpyrifos (0.01 g l(-1)). The partially purified rhamnolipid biosurfactant preparation, having a CMC of 0.2 g l(-1), was evaluated for its ability to enhance aqueous phase partitioning and degradation of chlorpyrifos (0.01 g l(-1)) by ChlD strain. The best degradation efficiency was observed at 0.1 g l(-1) supplement of biosurfactant, as validated by GC and HPLC studies. The addition of biosurfactant at 0.1 g l(-1) resulted in more than 98% degradation of chlorpyrifos when compared to 84% in the absence of biosurfactant after 120-h incubation. This first report, to the best of our knowledge, on enhanced degradation of chlorpyrifos in the presence of biosurfactant(s), would help in developing bioremediation protocols to counter accumulation of organophosphates to toxic/carcinogenic levels in environment.

Entomopathogenicity to Two Hemipteran Insects Is Common but Variable across Epiphytic Pseudomonas syringae Strains.

Science.gov (United States)

Smee, Melanie R; Baltrus, David A; Hendry, Tory A

2017-01-01

Strains of the well-studied plant pathogen Pseudomonas syringae show large differences in their ability to colonize plants epiphytically and to inflict damage to hosts. Additionally, P. syringae can infect some sap-sucking insects and at least one P. syringae strain is highly virulent to insects, causing death to most individuals within as few as 4 days and growing to high population densities within insect hosts. The likelihood of agricultural pest insects coming into contact with transient populations of P. syringae while feeding on plants is high, yet the ecological implications of these interactions are currently not well understood as virulence has not been tested across a wide range of strains. To investigate virulence differences across strains we exposed the sweet potato whitefly, Bemisia tabaci , and the pea aphid, Acyrthosiphon pisum , both of which are cosmopolitan agricultural pests, to 12 P. syringae strains. We used oral inoculations with bacteria suspended in artificial diet in order to assay virulence while controlling for other variables such as differences in epiphytic growth ability. Generally, patterns of pathogenicity remain consistent across the two species of hemipteran insects, with bacterial strains from phylogroup II, or genomospecies 1, causing the highest rate of mortality with up to 86% of individuals dead after 72 h post infection. The rate of mortality is highly variable across strains, some significantly different from negative control treatments and others showing no discernable difference. Interestingly, one of the most pathogenic strains to both aphids and whiteflies (Cit7) is thought to be non-pathogenic on plants. We also found Cit7 to establish the highest epiphytic population after 48 h on fava beans. Between the nine P. syringae strains tested for epiphytic ability there is also much variation, but epiphytic ability was positively correlated with pathogenicity to insects, suggesting that the two traits may be linked and that

Entomopathogenicity to Two Hemipteran Insects Is Common but Variable across Epiphytic Pseudomonas syringae Strains

Directory of Open Access Journals (Sweden)

Melanie R. Smee

2017-12-01

Full Text Available Strains of the well-studied plant pathogen Pseudomonas syringae show large differences in their ability to colonize plants epiphytically and to inflict damage to hosts. Additionally, P. syringae can infect some sap-sucking insects and at least one P. syringae strain is highly virulent to insects, causing death to most individuals within as few as 4 days and growing to high population densities within insect hosts. The likelihood of agricultural pest insects coming into contact with transient populations of P. syringae while feeding on plants is high, yet the ecological implications of these interactions are currently not well understood as virulence has not been tested across a wide range of strains. To investigate virulence differences across strains we exposed the sweet potato whitefly, Bemisia tabaci, and the pea aphid, Acyrthosiphon pisum, both of which are cosmopolitan agricultural pests, to 12 P. syringae strains. We used oral inoculations with bacteria suspended in artificial diet in order to assay virulence while controlling for other variables such as differences in epiphytic growth ability. Generally, patterns of pathogenicity remain consistent across the two species of hemipteran insects, with bacterial strains from phylogroup II, or genomospecies 1, causing the highest rate of mortality with up to 86% of individuals dead after 72 h post infection. The rate of mortality is highly variable across strains, some significantly different from negative control treatments and others showing no discernable difference. Interestingly, one of the most pathogenic strains to both aphids and whiteflies (Cit7 is thought to be non-pathogenic on plants. We also found Cit7 to establish the highest epiphytic population after 48 h on fava beans. Between the nine P. syringae strains tested for epiphytic ability there is also much variation, but epiphytic ability was positively correlated with pathogenicity to insects, suggesting that the two traits may be

Biosurfactant production by Pseudomonas fluorescens growing on molasses and its application in phenol degradation

Science.gov (United States)

Suryantia, Venty; Marliyana, Soerya Dewi; Wulandari, Astri

2015-12-01

A molasses based medium for the biosurfactant production by Pseudomonas fluorescens was developed, where the effect of pre-treated of molasses and medium composition were evaluated. Biosurfactant production was followed by measuring optical density (OD), surface tension and emulsifying index (E24) over 12 days of fermentation. The optimum condition for the biosurfactant production was obtained when a medium containing of 8 g/L nutrient broth, 5 g/L NaCl, 1 g/L NH4NO3 and 5% v/v pre-treated molasses with centrifugation was used as media with 3 days of fermentation. The biosurfactant was identified as a rhamnolipid type biosurfactant which had critical micelle concentration (CMC) value of 801 mg/L and was able to reduce the surface tension of the water from 80 mN/m to 51 mN/m. The biosurfactants had water in oil (w/o) emulsion type. Biosurfactant was able to emulsify various hydrocarbons, which were able to decrase the interfacial tension about 50-75% when benzyl chloride, anisaldehyde and palm oil were used as immiscible compounds. The biosurfactant exhibited the E24 value of about 50% and the stable emulsion was reached up to 30 days when lubricant was used as an immiscible compound. Up to 68% of phenol was degraded in the presence of biosurfactant within 15 days, whereas only 56% of phenol was degraded in the absence of biosurfactant. Overall, the results exhibited that molasses are recommended for the rhamnolipids production which possessed good surface-active properties and had potential application in the enhancement of phenol degradation.

Naphthalene: Drinking water health advisory

Energy Technology Data Exchange (ETDEWEB)

1990-03-01

The Drinking Water Health Advisory, Office of Water, U.S. Environmental Protection Agency, has issued its report on the chemical, naphthalene. Naphthalene is used in the manufacture of phthalic and anthranilic acids and other derivatives, and in making dyes; in the manufacture of resins, celluloid, lampblack and smokeless gunpowder; and as moth repellant, insecticide, anthelmintic, vermicide, and intestinal antiseptic. The report covers the following areas: the occurrence of the chemical in the environment; its environmental fate; the chemical's absorption, distribution, metabolism, and excretion in the human body; and its health effects on humans and animals, including its mutagenicity and carcinogenicity characteristics. Also included is the quantification of its toxicological effects.

Isolation and characterization of a novel native Bacillus thuringiensis strain BRC-HZM2 capable of degrading chlorpyrifos.

Science.gov (United States)

Wu, Songqing; Peng, Yan; Huang, Zhangmin; Huang, Zhipeng; Xu, Lei; Ivan, Gelbič; Guan, Xiong; Zhang, Lingling; Zou, Shuangquan

2015-03-01

Studies were carried out to isolate chlorpyrifos degrading Bacillus thuringiensis (Bt) strains from chlorpyrifos-contaminated samples. Six Bt strains (isolation rate 2.7%) were isolated by modified sodium acetate antibiotic heat treatment, and one novel strain (BRC-HZM2) was selected for further analysis. Phenotype and phylogeny analysis of this strain was conducted on the basis of biochemical reactions, antibiotic sensitivity, 16s rRNA genes, plasmid profile, insecticidal crystal protein profiles, and PCR-RFLP for cry and cyt genes. The degradation rate of chlorpyrifos in liquid culture was estimated during 48 h of incubation for the isolate BRC-HZM2. More than 50% of the initial chlorpyrifos concentration degraded within 12 h, 88.9% after 48 h. These results highlight the potential of the Bt strain for biological control and the bioremediation of environments contaminated with chlorpyrifos. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization of liquid-state fermentation conditions for the glyphosate degradation enzyme production of strain Aspergillus oryzae by ultraviolet mutagenesis.

Science.gov (United States)

Fu, Gui-Ming; Li, Ru-Yi; Li, Kai-Min; Hu, Ming; Yuan, Xiao-Qiang; Li, Bin; Wang, Feng-Xue; Liu, Cheng-Mei; Wan, Yin

2016-11-16

This study aimed to obtain strains with high glyphosate-degrading ability and improve the ability of glyphosate degradation enzyme by the optimization of fermentation conditions. Spore from Aspergillus oryzae A-F02 was subjected to ultraviolet mutagenesis. Single-factor experiment and response surface methodology were used to optimize glyphosate degradation enzyme production from mutant strain by liquid-state fermentation. Four mutant strains were obtained and named as FUJX 001, FUJX 002, FUJX 003, and FUJX 004, in which FUJX 001 gave the highest total enzyme activity. Starch concentration at 0.56%, GP concentration at 1,370 mg/l, initial pH at 6.8, and temperature at 30°C were the optimum conditions for the improved glyphosate degradation endoenzyme production of A. oryzae FUJX 001. Under these conditions, the experimental endoenzyme activity was 784.15 U/100 ml fermentation liquor. The result (784.15 U/100 ml fermentation liquor) was approximately 14-fold higher than that of the original strain. The result highlights the potential of glyphosate degradation enzyme to degrade glyphosate.

Plant-associated fluorescent Pseudomonas from red lateritic soil: Beneficial characteristics and their impact on lettuce growth.

Science.gov (United States)

Maroniche, Guillermo A; Rubio, Esteban J; Consiglio, Adrián; Perticari, Alejandro

2016-11-25

Fluorescent Pseudomonas are ubiquitous soil bacteria that usually establish mutualistic associations with plants, promoting their growth and health by several mechanisms. This makes them interesting candidates for the development of crop bio-inoculants. In this work, we isolated phosphate-solubilizing fluorescent Pseudomonas from the rhizosphere and inner tissues of different plant species growing in red soil from Misiones, Argentina. Seven isolates displaying strong phosphate solubilization were selected for further studies. Molecular identification by rpoD genotyping indicated that they belong to different species within the P. fluorescens and P. putida phylogenetic groups. Screening for in vitro traits such as phosphate solubilization, growth regulators synthesis or degradation, motility and antagonism against phytopathogens or other bacteria, revealed a unique profile of characteristics for each strain. Their plant growth-promoting potential was assayed using lettuce as a model for inoculation under controlled and greenhouse conditions. Five of the strains increased the growth of lettuce plants. Overall, the strongest lettuce growth promoter under both conditions was strain ZME4, isolated from inner tissues of maize. No clear association between lettuce growth promotion and in vitro beneficial traits was detected. In conclusion, several phosphate solubilizing pseudomonads from red soil were isolated that display a rich array of plant growth promotion traits, thus showing a potential for the development of new inoculants.

Genome sequence of the agar-degrading marine bacterium Alteromonadaceae sp. strain G7.

Science.gov (United States)

Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun; Hong, Soon-Kwang; Kim, Jihyun F

2012-12-01

Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.

Genome Sequence of the Agar-Degrading Marine Bacterium Alteromonadaceae sp. Strain G7

OpenAIRE

Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun; Hong, Soon-Kwang; Kim, Jihyun F.

2012-01-01

Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.

Antifungal activity and genetic diversity of selected Pseudomonas spp. from maize rhizosphere in Vojvodina

Directory of Open Access Journals (Sweden)

Jošić Dragana

2012-01-01

Full Text Available Antibiotic production by plant-associated microorganisms represents an environmentally compatible method of disease control in agriculture. However, a vide application of bacterial strains needs careful selection and genetic characterization. In this investigation, selected Pseudomonas strains were characterized by rep-PCR methods using ERIC and (GTG5 primers, and partial 16S rDNA sequence analysis. None of strains produced homoserine lactones (C4, C6, C8 as quorum sensing signal molecules. Very poor production of phenazines and no significant fungal inhibition was observed for PS4 and PS6 strains. High amount of phenazines were produced by Pseudomonas sp. strain PS2, which inhibited mycelial growth of 10 phytopatogenic fungi in percent of 25 (Verticillium sp. to 65 (Fusarium equiseti. Genetic characterization of the Pseudomonas sp. PS2 and evaluation of phenazines production, as the main trait for growth inhibition of phytopathogenic fungi, will allow its application as a biosafe PGPR for field experiments of plant disease control. [Projekat Ministarstva nauke Republike Srbije, br. III 46007: New indigenous bacterial isolates Lysobacter and Pseudomonas as an important sources of metabolites useful for biotechnology, plant growth stimulation and disease control: From isolates to inoculants

Technological Potential of Lactobacillus Strains Isolated from Fermented Green Olives: In Vitro Studies with Emphasis on Oleuropein-Degrading Capability

Directory of Open Access Journals (Sweden)

Massimo Iorizzo

2016-01-01

Full Text Available Technological properties of two strains of Lactobacillus plantarum (B3 and B11 and one of Lactobacillus pentosus (B4, previously isolated from natural fermented green olives, have been studied in vitro. Acidifying ability, salt, temperature, and pH tolerances of all strains were found in the range reported for similar strains produced in Italy and optimal growth conditions were found to be 6.0–8.0 pH, 15–30°C temperature, and less than 6% NaCl. Moreover, all strains showed very good tolerance to common olive phenol content (0.3% total phenol and high oleuropein-degrading capability. It was found that medium composition affected the bacterial oleuropein degradation. B11 strain grown in a nutrient-rich medium showed a lower oleuropein-degrading action than when it was cultivated in nutrient-poor medium. Furthermore, enzymatic activity assays revealed that oleuropein depletion did not correspond to an increase of hydroxytyrosol, evidencing that bacterial strains could efficiently degrade oleuropein via a mechanism different from hydrolysis.

Apparent Contradiction: Psychrotolerant Bacteria from Hydrocarbon-Contaminated Arctic Tundra Soils That Degrade Diterpenoids Synthesized by Trees

Science.gov (United States)

Yu, Zhongtang; Stewart, Gordon R.; Mohn, William W.

2000-01-01

Resin acids are tricyclic terpenoids occurring naturally in trees. We investigated the occurrence of resin acid-degrading bacteria on the Arctic tundra near the northern coast of Ellesmere Island (82°N, 62°W). According to most-probable-number assays, resin acid degraders were abundant (103 to 104 propagules/g of soil) in hydrocarbon-contaminated soils, but they were undetectable (soil) in pristine soils from the nearby tundra. Plate counts indicated that the contaminated and the pristine soils had similar populations of heterotrophs (106 to 107 propagules/g of soil). Eleven resin acid-degrading bacteria belonging to four phylogenetically distinct groups were enriched and isolated from the contaminated soils, and representative isolates of each group were further characterized. Strains DhA-91, IpA-92, and IpA-93 are members of the genus Pseudomonas. Strain DhA-95 is a member of the genus Sphingomonas. All four strains are psychrotolerant, with growth temperature ranges of 4°C to 30°C (DhA-91 and DhA-95) or 4°C to 22°C (IpA-92 and IpA-93) and with optimum temperatures of 15 to 22°C. Strains DhA-91 and DhA-95 grew on the abietanes, dehydroabietic and abietic acids, but not on the pimaranes, isopimaric and pimaric acids. Strains IpA-92 and IpA-93 grew on the pimaranes but not the abietanes. All four strains grew on either aliphatic or aromatic hydrocarbons, which is unusual for described resin acid degraders. Eleven mesophilic resin acid degraders did not use hydrocarbons, with the exception of two Mycobacterium sp. strains that used aliphatic hydrocarbons. We conclude that hydrocarbon contamination in Arctic tundra soil indirectly selected for resin acid degraders, selecting for hydrocarbon degraders that coincidentally use resin acids. Psychrotolerant resin acid degraders are likely important in the global carbon cycle and may have applications in biotreatment of pulp and paper mill effluents. PMID:11097882

Biosorption of uranium by Pseudomonas aeruginosa strain CSU: Characterization and comparison studies

International Nuclear Information System (INIS)

Hu, M.Z.C.; Norman, J.M.; Faison, B.D.; Reeves, M.E.

1996-01-01

Pseudomonas aeruginosa strain CSU, a nongenetically engineered bacterial strain known to bind dissolved hexavalent uranium (as UO 2 2+ and/or its cationic hydroxo complexes) was characterized with respect to its sorptive activity. The uranium biosorption equilibrium could be described by the Langmuir isotherm. The rate of uranium adsorption increased following permeabilization of the outer and/or cytoplasmic membrane by organic solvents such as acetone. P. aeruginosa CSU biomass was significantly more sorptive toward uranium than certain novel, patented biosorbents derived from algal or fungal biomass sources. P. aeruginosa CSU biomass was also competitive with commercial cation-exchange resins, particularly in the presence of dissolved transition metals. Uranium binding by P. aeruginosa CSU was clearly pH dependent. Uranium loading capacity increased with increasing pH under acidic conditions, presumably as a function of uranium speciation and due to the H + competition at some binding sites. Nevertheless, preliminary evidence suggests that this microorganism is also capable of binding anionic hexavalent uranium complexes. Ferric iron was a strong inhibitor of uranium binding to P. aeruginosa CSU biomass, and the presence of uranium also decreased the Fe 3+ loading when the biomass was not saturated with Fe 3+ . Thus, a two-state process in which iron and uranium are removed in consecutive steps was proposed for efficient use of the biomass as a biosorbent in uranium removal from mine wastewater, especially acidic leachates

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

Science.gov (United States)

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

2017-10-01

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

Evaluation of Aliphatic and Aromatic Compounds Degradation by Indigenous Bacteria Isolated from Soil Contaminated with Petroleum

Directory of Open Access Journals (Sweden)

Farhad Gilavand

2015-12-01

Full Text Available Background:  The major of this study was to isolate oil-degrading bacteria from soil contaminated with petroleum and examining the removal of hydrocarbons by these bacteria. Methods: Oil-degrading colonies were purified from the samples obtained of around Ahvaz oil wells. Organic matter degradation was investigated with 1 g of crude oil in basal salt medium (BSM as sole carbon source. The growth rate was determined through total protein assay and hydrocarbon consuming was measured through organic carbon oxidation and titration by dichromate as oxidizing agent. Results: Two potential isolates named S1 and S2 strains were screened and identified as Planococcus and Pseudomonas aeruginosa. As results for S1 and S2 could degrade 80.86 and 65.6% of olive oil, 59.6 and 35.33 of crude oil, while 32 and 26.15 % of coal tar were consumed during 14 days incubation. Conclusion: The results of this investigation showed these indigenous strains high capability to biodegradation at short time and are desirable alternatives for treatment of oil pollutants.

Further studies of the thermal and photochemical diels-alder reactions of N-methyl-1,2,4-triazoline-3,5-dione (MeTAD) with naphthalene and some substituted naphthalenes

Science.gov (United States)

Breton; Newton

2000-05-19

MeTAD thermally reacted with naphthalene (2) and methylated naphthalenes to give equilibrium mixtures of starting materials and [4 + 2] cycloadducts. Methyl substitution on the naphthalene ring generally increased both the amount of cycloadduct formed and the rate of cycloaddition relative to 2. The isolated cycloadducts were all thermally labile and quantitatively reverted to the parent naphthalene in the presence of 2,3-dimethyl-2-butene as a trap for liberated MeTAD. The rates of the cycloreversion reactions were affected by substitution patterns but not appreciably by solvent. A mechanism for the cycloaddition reaction is presented that proposes the involvement of a charge-transfer complex. Photochemically, MeTAD demonstrated lower regioselectivity in its reactions with substituted naphthalenes relative to the corresponding thermal reactions.

Comprehensive proteome analysis of the response of Pseudomonas putida KT2440 to the flavor compound vanillin.

Science.gov (United States)

Simon, Oliver; Klaiber, Iris; Huber, Armin; Pfannstiel, Jens

2014-09-23

Understanding of the molecular response of bacteria to precursors, products and environmental conditions applied in bioconversions is essential for optimizing whole-cell biocatalysis. To investigate the molecular response of the potential biocatalyst Pseudomonas putida KT2440 to the flavor compound vanillin we applied complementary gel- and LC-MS-based quantitative proteomics approaches. Our comprehensive proteomics survey included cytoplasmic and membrane proteins and led to the identification and quantification of 1614 proteins, corresponding to 30% of the total KT2440 proteome. 662 proteins were altered in abundance during growth on vanillin as sole carbon source as compared to growth on glucose. The proteome response entailed an increased abundance of enzymes involved in vanillin degradation, significant changes in central energy metabolism and an activation of solvent tolerance mechanisms. With respect to vanillin metabolism, particularly enzymes belonging to the β-ketoadipate pathway including a transcriptional regulator and porins specific for vanillin uptake increased in abundance. However, catabolism of vanillin was not dependent on vanillin dehydrogenase (Vdh), as shown by quantitative proteome analysis of a Vdh-deficient KT2440 mutant (GN235). Other aldehyde dehydrogenases that were significantly increased in abundance in response to vanillin may replace Vdh and thus may represent interesting targets for improving vanillin production in P. putida KT2440. The high demand for the flavor compound vanillin by the food and fragrance industry makes natural vanillin from vanilla pods a scarce and expensive resource rendering its biotechnological production economically attractive. Pseudomonas bacteria are metabolically very versatile and accept a broad range of hydrocarbons as carbon source making them suitable candidates for bioconversion processes. This work describes the impact of vanillin on the metabolism of the reference strain P. putida KT2440 on a

Isolation and characterization of Halomonas sp. strain C2SS100, a hydrocarbon-degrading bacterium under hypersaline conditions.