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1.
Water Sci Technol ; 86(8): 1859-1875, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36315081

RESUMO

Biosurfactant are Surfactants produced by certain microorganisms. These biosurfactants increase the biodegradability of insoluble pollutants. In this study, the fermentation products of Pseudomonas stutzeri Lh-42 (PS) and Rhodococcus sp. PR-1 (RD) were studied by Oil spreading method, emulsifying activity and infrared spectrum analysis. It was proved that these fermentation products were biosurfactant. And then the fermentation conditions of PS, RD were optimised by Placket-Burman (PB) design, hill-climbing experiment and response surface methodology (RSM). N source and liquid loading were significant factors in the fermentation of PS, while C source and speed were significant factors in the fermentation of RD. The surface tension was found to be as low as 39.53 ± 0.25 mN/m for the fermentation conditions of PS with an N source of 4.62 ± 0.41 g and a liquid loading of 28.4 ± 0.3%. The surface tension was 40.70 ± 0.47 mN/m for the incubation conditions of RD with a C source of 26.94 ± 0.62 g and a rotational speed of 210 r/min. Finally, the experimental results for the degradation of oily sludge showed that the degradation rate of oily sludge was improved when the fermentation conditions were optimised. The results of the infrared spectroscopy analysis showed that the organic matter content of the oily sludge treated with PS bacteria was significantly reduced after the optimised fermentation. This study provides a theoretical reference for further use of these bacteria to produce biosurfactants to treat organic matter.


Assuntos
Bactérias , Esgotos , Esgotos/química , Bactérias/metabolismo , Tensoativos/química , Fermentação , Pseudomonas/metabolismo
2.
J Pak Med Assoc ; 72(4): 761-763, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35614618

RESUMO

Pseudomonas balearica, a saprophyte found in marshy and marine habitats, is not routinely differentiated from P. aeruginosa and P. stutzeri using automated systems and hence has not been reported from clinical samples. This study describes the identification of P. balearica using MALDI-TOF-MS and 16S rDNA sequence from a patient admitted to an intensive care unit (I.C.U.). The isolate was found to be Verona integron-mediated Metallo-b-lactamase (V.I.M.), and Vietnam extended-spectrum b-lactamase (V.E.B.) producer and resistant to Ceftriaxone, Imipenem, and Tobramycin. P. balearica can be a source for horizontal transfer of blaVEB and blaVIM. Its pathogenesis has yet to be understood.


Assuntos
Infecções por Pseudomonas , beta-Lactamases , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Humanos , Integrons/genética , Testes de Sensibilidade Microbiana , Pseudomonas , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Vietnã , beta-Lactamases/genética , beta-Lactamases/metabolismo
3.
J Appl Microbiol ; 130(6): 1949-1959, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33145923

RESUMO

AIM: To test the potential of a newly isolated strain of Pseudomonas sp., and its optimization for carrying out bioremediation of textile azo dye Procion Red H-3B. METHOD: The isolation of the bacterial strain was done from a textile waste dumping site, followed by screening techniques to study the decolourization of an azo dye. The isolated pure culture was selected by its ability to form clear zones. The biochemical tests gave partial confirmation of the isolates, and the phylogenic analysis made the complete confirmation by 16S rRNA sequencing. RESULT: The identified strain belongs to the genus Pseudomonas. The phylogenic analysis confirmed that the strain belongs to Pseudomonas stutzeri. The culture exhibited maximum decolourization at pH between 6 and 8, the optimum at pH 7·5 and 37°C temperature. A maximum of 96% discolouration was observed at 50 mg l-1 of initial dye concentration after 24 h of incubation period. At a dye concentration equally or greater than 600 mg l-1 , the colour removal was drastically decreased to 30%. The use of fructose at 1% (w/v) and peptone 0·5% (w/v) concentration for 24 h of incubation, as carbon and nitrogen source, showed luxuriant decolourization. The results showed that the Pseudomonas sp. holds immense potential in treating textile effluents containing the dye Procion red H-3B. CONCLUSION: Pseudomonas is a known organism in bioremediation of various textile dyes but not much has being reported about the role of P. stutzeri in the bioremediation of azo dyes. This study revealed the immense potential of this strain in degrading the azo dyes. SIGNIFICANCE AND IMPACT OF THE STUDY: The strain shows prospective for industrial application in the field of textile wastewater treatment. Bioremediation is comparatively cheaper and more effective treatment, thus holds promising future for a cleaner environment.


Assuntos
Compostos Azo/metabolismo , Corantes/metabolismo , Pseudomonas/metabolismo , Têxteis , Poluentes Químicos da Água/metabolismo , Compostos Azo/análise , Biodegradação Ambiental , Corantes/análise , Concentração de Íons de Hidrogênio , Filogenia , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Temperatura , Águas Residuárias/química , Águas Residuárias/microbiologia , Descoloração da Água/métodos , Poluentes Químicos da Água/análise
4.
Recent Pat Food Nutr Agric ; 11(2): 124-136, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31322080

RESUMO

BACKGROUND: The present investigation aimed to evaluate the role of Plant Growth- Promoting Rhizobacteria (PGPR) and Ag-nanoparticles on two varieties (American variety, Poinsett 76 and Desi variety, Sialkot selection) of cucumber plants. METHODS: Cucumber seeds prior to sowing, were inoculated with two strains of PGPR, Pseudomonas putida (KX574857) and Pseudomonas stutzeri (KX574858) at the rate of 106 cells/ml. Agnanoparticles (5ppm) were sprayed on the plant at early vegetative phase 27 d after sowing. RESULTS: The proline, sugar, protein, phenolics, flavonoids, chlorophyll and carotenoids contents of leaves of plants and the activities of Phenylalanine Ammonia-Lyase (PAL), Superoxide Dismutase (SOD) and Catalase (CAT) were determined from leaves of plants at early vegetative phase. After 3 months of seeds sowing, Ag-nanoparticles enhanced the length of root but decreased the length of shoot and fresh weight of root and shoot as compared to control whereas, the leaf protein, proline, phenolics, flavonoids, chlorophyll b, total chlorophyll, sugar and Phenylalanine Ammonia-Lyase (PAL) activity of plants were increased significantly over control. Ag-nanoparticles also suppressed the effect of PGPR for root, shoot length but augmented the protein and phenolics contents of leaves of both the varieties. CONCLUSION: The combined treatment of Ag-nanoparticles and PGPR enhanced flavonoids content of leaves and the activities of PAL, SOD and CAT in leaves of plants over control. Agnanoparticles effectively increased the Phenylalanine Ammonia-Lyase (PAL), Catalase (CAT) and superoxide dismutase (SOD) activities in leaves of both the varieties. Pseudomonas putida may be used either alone or in combination with Ag-nanoparticles to enhance the antioxidant and defense enzyme activities. Hence, the plant can tolerate the diseases and stresses in a much better way with higher protein and phenolics content.


Assuntos
Cucumis sativus , Nanopartículas , Brotos de Planta , Pseudomonas/crescimento & desenvolvimento , Prata/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Antioxidantes/metabolismo , Carotenoides/metabolismo , Catalase/metabolismo , Clorofila/metabolismo , Cucumis sativus/enzimologia , Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/metabolismo , Cucumis sativus/microbiologia , Estresse Oxidativo/efeitos dos fármacos , Fenilalanina Amônia-Liase/metabolismo , Folhas de Planta , Raízes de Plantas , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/microbiologia , Sementes/microbiologia , Especificidade da Espécie , Superóxido Dismutase/metabolismo
5.
Microb Biotechnol ; 13(1): 118-133, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30461205

RESUMO

In agricultural production, sustainability is currently one of the most significant concerns. The genetic modification of plant growth-promoting rhizobacteria may provide a novel way to use natural bacteria as microbial inoculants. In this study, the root-colonizing strain Pseudomonas protegens Pf-5 was genetically modified to act as a biocontrol agent and biofertilizer with biological nitrogen fixation activity. Genetic inactivation of retS enhanced the production of 2,4-diacetylphloroglucinol, which contributed for the enhanced antifungal activity. Then, the entire nitrogenase island with native promoter from Pseudomonas stutzeri DSM4166 was introduced into a retS mutant strain for expression. Root colonization patterns assessed via confocal laser scanning microscopy confirmed that GFP-tagged bacterial were mainly located on root surfaces and at the junctions between epidermal root cells. Moreover, under pathogen and N-limited double treatment conditions, the fresh weights of seedlings inoculated with the recombinant retS mutant-nif strain were increased compared with those of the control. In conclusion, this study has innovatively developed an eco-friendly alternative to the agrochemicals that will benefit global plant production significantly.


Assuntos
Proteínas de Bactérias , Agentes de Controle Biológico , Fixação de Nitrogênio , Engenharia de Proteínas , Pseudomonas stutzeri , Nitrogenase/metabolismo , Raízes de Plantas , Pseudomonas , Pseudomonas stutzeri/metabolismo
6.
Nat Microbiol ; 5(2): 314-330, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31844298

RESUMO

Legumes obtain nitrogen from air through rhizobia residing in root nodules. Some species of rhizobia can colonize cereals but do not fix nitrogen on them. Disabling native regulation can turn on nitrogenase expression, even in the presence of nitrogenous fertilizer and low oxygen, but continuous nitrogenase production confers an energy burden. Here, we engineer inducible nitrogenase activity in two cereal endophytes (Azorhizobium caulinodans ORS571 and Rhizobium sp. IRBG74) and the well-characterized plant epiphyte Pseudomonas protegens Pf-5, a maize seed inoculant. For each organism, different strategies were taken to eliminate ammonium repression and place nitrogenase expression under the control of agriculturally relevant signals, including root exudates, biocontrol agents and phytohormones. We demonstrate that R. sp. IRBG74 can be engineered to result in nitrogenase activity under free-living conditions by transferring a nif cluster from either Rhodobacter sphaeroides or Klebsiella oxytoca. For P. protegens Pf-5, the transfer of an inducible cluster from Pseudomonas stutzeri and Azotobacter vinelandii yields ammonium tolerance and higher oxygen tolerance of nitrogenase activity than that from K. oxytoca. Collectively, the data from the transfer of 12 nif gene clusters between 15 diverse species (including Escherichia coli and 12 rhizobia) help identify the barriers that must be overcome to engineer a bacterium to deliver a high nitrogen flux to a cereal crop.


Assuntos
Grão Comestível/metabolismo , Grão Comestível/microbiologia , Fixação de Nitrogênio , Azorhizobium caulinodans/genética , Azorhizobium caulinodans/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Genes Bacterianos , Engenharia Metabólica , Família Multigênica , Fixação de Nitrogênio/genética , Nitrogenase/genética , Nitrogenase/metabolismo , Nodulação/genética , Pseudomonas/genética , Pseudomonas/metabolismo , Rhizobium/genética , Rhizobium/metabolismo , Simbiose/genética
7.
Plant Cell ; 32(2): 486-507, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31757927

RESUMO

Nitrogen (N) limits crop yield, and improvement of N nutrition remains a key goal for crop research; one approach to improve N nutrition is identifying plant-interacting, N2-fixing microbes. Rhodotorula mucilaginosa JGTA-S1 is a basidiomycetous yeast endophyte of narrowleaf cattail (Typha angustifolia). JGTA-S1 could not convert nitrate or nitrite to ammonium but harbors diazotrophic (N2-fixing) endobacteria (Pseudomonas stutzeri) that allow JGTA-S1 to fix N2 and grow in a N-free environment; moreover, P. stutzeri dinitrogen reductase was transcribed in JGTA-S1 even under adequate N. Endobacteria-deficient JGTA-S1 had reduced fitness, which was restored by reintroducing P. stutzeri JGTA-S1 colonizes rice (Oryza sativa), significantly improving its growth, N content, and relative N-use efficiency. Endofungal P. stutzeri plays a significant role in increasing the biomass and ammonium content of rice treated with JGTA-S1; also, JGTA-S1 has better N2-fixing ability than free-living P. stutzeri and provides fixed N to the plant. Genes involved in N metabolism, N transporters, and NODULE INCEPTION-like transcription factors were upregulated in rice roots within 24 h of JGTA-S1 treatment. In association with rice, JGTA-S1 has a filamentous phase and P. stutzeri only penetrated filamentous JGTA-S1. Together, these results demonstrate an interkingdom interaction that improves rice N nutrition.


Assuntos
Bactérias/metabolismo , Basidiomycota/metabolismo , Fixação de Nitrogênio/fisiologia , Nitrogênio/metabolismo , Oryza/metabolismo , Oryza/microbiologia , Rhodotorula/metabolismo , Compostos de Amônio , Basidiomycota/crescimento & desenvolvimento , Endófitos/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/crescimento & desenvolvimento , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Pseudomonas/metabolismo , Pseudomonas stutzeri/metabolismo , Rhodotorula/crescimento & desenvolvimento , Rhodotorula/isolamento & purificação , Simbiose , Transcriptoma
8.
Appl Microbiol Biotechnol ; 103(21-22): 8853-8861, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31642950

RESUMO

Cost and energy reductions in the production process of bismuth chalcogenide (BC) semiconductor materials are essential to make thermoelectric generators comprised of BCs profitable and CO2 neutral over their life cycle. In this study, as an eco-friendly production method, bismuth selenide (Bi2Se3) nanoparticles were synthesized using the following five strains of chalcogen-metabolizing bacteria: Pseudomonas stutzeri NT-I, Pseudomonas sp. RB, Stenotrophomonas maltophilia TI-1, Ochrobactrum anthropi TI-2, and O. anthropi TI-3 under aerobic conditions. All strains actively volatilized selenium (Se) by reducing selenite, possibly to organoselenides. In the growth media containing bismuth (Bi) and Se, all strains removed Bi and Se concomitantly and synthesized nanoparticles containing Bi and Se as their main components. Particles synthesized by strain NT-I had a theoretical elemental composition of Bi2Se3, whereas those synthesized by other strains contained a small amount of sulfur in addition to Bi and Se, making strain NT-I the best Bi2Se3 synthesizer among the strains used in this study. The particle sizes were 50-100 nm in diameter, which is sufficiently small for nanostructured semiconductor materials that exhibit quantum size effect. Successful synthesis of Bi2Se3 nanoparticles could be attributed to the high Se-volatilizing activities of the bacterial strains. Selenol-containing compounds as intermediates of Se-volatilizing metabolic pathways, such as methane selenol and selenocysteine, may play an important role in biosynthesis of Bi2Se3.


Assuntos
Calcogênios/metabolismo , Ochrobactrum anthropi/metabolismo , Compostos Organosselênicos/metabolismo , Pseudomonas/metabolismo , Stenotrophomonas maltophilia/metabolismo , Bismuto , Nanopartículas Metálicas/microbiologia , Compostos de Selênio , Semicondutores/microbiologia
9.
J Photochem Photobiol B ; 200: 111655, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31655456

RESUMO

Textile effluent is often difficult to manage as it contains a high concentration of toxic and recalcitrant synthetic dyes. In this study, congo Red and textile effluent were treated by electrochemical oxidation using RuO2-IrO2 coated titanium electrode as an anode followed by biodecolorization using Pseudomonas stutzeri MN1 and Acinetobacter baumannii MN3. Effluent pre-treatment is often necessary to minimize the inhibitory effects of textile dyes on dye degrading bacterial during bio-treatment. The pre-treatment of Congo Red by electrochemical oxidation for 10 min resulted in a decolorization rate of 98% at a pH, NaCl concentration, and current density of 7, 2 g L-1, and 20 mA cm-2. Subsequent bio-treatment of the pretreated Congo Red enhanced the biodegradation to 93%. The COD removal efficiency in real textile effluent following electrochemical pretreatment and biological treatment using bacterial consortium were 3.8% and 93%, respectively. Therefore, integrating electrochemical oxidation and microbial consortia offers an effective and environmentally friendly approach for treating complex industrial effluents.


Assuntos
Biodegradação Ambiental , Vermelho Congo/química , Técnicas Eletroquímicas/métodos , Têxteis , Poluentes Químicos da Água/química , Acinetobacter/fisiologia , Compostos Azo/química , Vermelho Congo/metabolismo , Eletrodos , Concentração de Íons de Hidrogênio , Irídio/química , Oxirredução , Pseudomonas/fisiologia , Compostos de Rutênio/química , Cloreto de Sódio/química , Titânio/química , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/metabolismo
10.
G3 (Bethesda) ; 9(5): 1321-1329, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30910818

RESUMO

Strain SCT is an iodate-reducing bacterium isolated from marine sediment in Kanagawa Prefecture, Japan. In this study, we determined the draft genome sequence of strain SCT and compared it to complete genome sequences of other closely related bacteria, including Pseudomonas stutzeri A phylogeny inferred from concatenation of core genes revealed that strain SCT was closely related to marine isolates of P. stutzeri Genes present in the SCT genome but absent from the other analyzed P. stutzeri genomes comprised clusters corresponding to putative prophage regions and possible operons. They included pil genes, which encode type IV pili for natural transformation; the mer operon, which encodes resistance systems for mercury; and the pst operon, which encodes a Pi-specific transport system for phosphate uptake. We found that strain SCT had more prophage-like genes than the other P. stutzeri strains and that the majority (70%) of them were SCT strain-specific. These genes, encoded on distinct prophage regions, may have been acquired after branching from a common ancestor following independent phage transfer events. Thus, the genome sequence of Pseudomonas sp. strain SCT can provide detailed insights into its metabolic potential and the evolution of genetic elements associated with its unique phenotype.


Assuntos
Organismos Aquáticos/genética , Genoma Bacteriano , Genômica , Sedimentos Geológicos/microbiologia , Pseudomonas/classificação , Pseudomonas/genética , Organismos Aquáticos/classificação , Biodegradação Ambiental , Biologia Computacional/métodos , Elementos de DNA Transponíveis , Genômica/métodos , Anotação de Sequência Molecular , Filogenia , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , Sequenciamento Completo do Genoma
11.
Environ Int ; 127: 114-124, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30913456

RESUMO

We investigated remediation of phenol from water using microbe-plant partnerships. Co-introduction of maize seedlings, Pseudomonas fluorescens rifampicin-resistant P13 and P. stutzeri P7 carrying self-transmissible TOL-like plasmids reduced phenol content in water at lower phenol concentrations (25, 50, and 75 mg/L), similar to individual introduction of the bacteria. Co-introduction of plants and bacteria significantly reduced phenol content in water at higher phenol concentrations (100, 125, and 150 mg/L) compared to using individual introduction of the bacteria. Moreover, TOL-like plasmids were transferred from P7 to P13. Addition of plants promoted the growth of both strains, leading to increased plasmid transfer. At higher phenol concentrations, addition of plants resulted in increases of catechol 2, 3-dioxygenase (C23O) activity and reduction in level of reactive oxygen species (ROS) of bacteria in the degradation experiments. Increased plasmid transfer and C23O activity and reduction in ROS level might be the major reasons why plants promote bacterial degradation of phenol at higher phenol concentrations. Furthermore, root exudate of maize seedlings and artificial root exudate (ARE) constructed using major components of the root exudate had the same effects on bacterial activities. Unlike the ARE, deletion of glucose, arabinose, or fructose or all the monosaccharides from ARE resulted in no increase in numbers of both strains and in plasmid transfer. At the higher phenol concentrations, deletion of glutamic acid, aspartic acid, alanine, or glycine or all the amino acids did not stimulate bacterial C23O activity. Deletion of fumaric, oxaloacetic or citric acids still reduced bacterial ROS level as ARE did, but, deletion of all the organic acids or DIMBOA, a hydroxamic acid, did not reduce bacterial ROS level as ARE did. The data showed that each monosaccharide might be important for sufficient numbers of plant-associated bacteria and increased plasmid transfer while each amino acid might be important for maintaining bacterial C23O activity and that DIMBOA might be responsible for the decrease in ROS levels. These results are the basis for efficient remediation of phenol from water by microbe-plant partnerships and further studies on the mechanism of rhizobacterium-plant interaction.


Assuntos
Fenóis/metabolismo , Água/química , Zea mays/metabolismo , Raízes de Plantas/metabolismo , Plasmídeos , Pseudomonas/metabolismo , Plântula/metabolismo
12.
Environ Monit Assess ; 191(2): 118, 2019 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-30706145

RESUMO

The aim of this study was to know the biodiversity of total microorganisms contained in two polychlorinated biphenyl-contaminated aged soils and evaluate the strategies of bioaugmentation and biostimulation to biodegrade the biphenyls. Besides, the aerobic cultivable microorganisms were isolated and their capacity to biodegrade a commercial mixture of six congeners of biphenyls was evaluated. Biodiversity of contaminated soils was dominated by Actinobacteria (42.79%) and Firmicutes (42.32%) phyla, and others in smaller proportions such as Proteobacteria, Gemmatimonadetes, Chloroflexi, and Bacteroidetes. At the genus level, the majority of the population did not exceed 7% of relative abundance, including Bacillus, Achromobacter, Clostridium, and Pontibacter. Furthermore, four autochthonous bacterial cultures were possible isolates from the soils, which were identified by partial sequencing of the 16S rRNA gene, as Bacillus sp., Achromobacter sp., Pseudomonas stutzeri, and Bacillus subtilis, which were used for the bioaugmentation process. The bioaugmentation and biostimulation strategies achieved a biodegradation of about 60% of both soils after 8 weeks of the process; also, the four isolates were used as mixed culture to biodegrade a commercial mix of six polychlorinated biphenyl congeners; after 4 weeks of incubation, the concentration decreased from 0.5 mg/L to 0.23 mg/L.


Assuntos
Bactérias/isolamento & purificação , Monitoramento Ambiental/métodos , Bifenilos Policlorados/análise , Microbiologia do Solo , Poluentes do Solo/análise , Bactérias/classificação , Biodegradação Ambiental , Biodiversidade , México , Bifenilos Policlorados/metabolismo , Pseudomonas/isolamento & purificação , Solo/química , Poluentes do Solo/metabolismo
13.
Comput Biol Chem ; 74: 190-200, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29627694

RESUMO

Lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) catalyzes tri-, di-, and monoacyl glycerol of fat into glycerol and fatty acids. It has important roles in the digestion of lipids in living organisms and industrially as laundry detergents along with proteases. The microbial lipases are more stable, active and economically feasible compared to plant and animal sources. Hence, much attention was given to the maximum production of the enzyme from the microbial sources. The phylogenetic analysis revealed that the amino acid sequence of lipase protein and their corresponding cDNA of Pseudomonas aeruginosa clustered with Pseudomonas stutzeri among different species of Pseudomonas, while P. aeruginosa PA1 clustered with P. aeruginosa SJTD-1 among different strains of P. aeruginosa. The lipase of P. aeruginosa PA1 was a monomeric, acidic and thermostable protein having a molecular weight ranging in between 32.72 to 34.89 kDa. The protein was abundant with random coils and alpha helices in its secondary structure. The tertiary model showed 96.310 score as an overall quality factor. Hence, this in silico study gives some useful information about the lipase protein without performing crystal structure assessment by X-ray Crystallography or NMR study in wet lab experiments which could be helpful for isolation and characterization of the enzyme in vitro.


Assuntos
Lipase/química , Lipase/metabolismo , Filogenia , Pseudomonas/enzimologia , Sequência de Aminoácidos , Cristalografia por Raios X , Lipase/genética , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Conformação Proteica , Pseudomonas/classificação
14.
Appl Biochem Biotechnol ; 185(3): 691-704, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29292474

RESUMO

Considering the importance of methylotrophs in industrial wastewater treatment, focus of the present study was on utilization of a methylotrophic bacterial consortium as a microbial seed for biotreatment of a variety of industrial effluents. For this purpose, a mixed bacterial methylotrophic AC (Ankleshwar CETP) consortium comprising of Bordetella petrii AC1, Bacillus licheniformis AC4, Salmonella subterranea AC5, and Pseudomonas stutzeri AC8 was used. The AC consortium showed efficient biotreatment of four industrial effluents procured from fertilizer, chemical and pesticide industries, and common effluent treatment plant by lowering their chemical oxygen demand (COD) of 950-2000 mg/l to below detection limit in 60-96 h in 6-l batch reactor and 9-15 days in 6-l continuous reactor. The operating variables of wastewater treatment, viz. COD, BOD, pH, MLSS, MLVSS, SVI, and F/M ratio of these effluents, were also maintained in the permissible range in both batch and continuous reactors. Therefore, formation of the AC consortium has led to the development of an efficient microbial seed capable of treating a variety of industrial effluents containing pollutants generated from their respective industries.


Assuntos
Bacillus/metabolismo , Biodegradação Ambiental , Bordetella/metabolismo , Resíduos Industriais , Pseudomonas/metabolismo , Salmonella/metabolismo , Águas Residuárias/microbiologia , Poluentes Químicos da Água/metabolismo , Reatores Biológicos , Indústria Química , Concentração de Íons de Hidrogênio , Oxigênio/metabolismo
15.
World J Microbiol Biotechnol ; 33(7): 148, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28634714

RESUMO

Bioaugmentation is substantially determined by pre-attached communities in biological stuffing systems. However, the inevitable changes of microbial community shift occurred between pre-attached microorganisms on stuffing material and other existing communities in wastewater. Targeting at nitrogen removal in aerobic denitrification reactors, biological augmentation was built by polyurethane supporting material and aerobic denitrification bacteria of Pseudomonas stutzeri strains were primarily colonized. The total nitrogen removal reached a high efficiency of 77 ± 6%, resulting from a relative high nitrate removal (90%) and a low nitrite production of 24 mg l-1. The nitrate removal was kept 10% higher using preattached strains than that using wastewater communities. During the bioaugmentation process, abundant bacteria related to nitrogen removal were evolutively enriched to compete with preattached Pseudomonas stutzeri. The most abundant bacteria growing up in the biofilm belonged to various Classes of Proteobacteria Phylum. A noticeable nitrite production with a relative low TN removal efficiency occurred when Brucella sp. and Brevundimonas sp. were simultaneously enriched in place of Pseudomonas, because Brevundimonas also accumulated nitrite during denitrification under an aerobic condition. The results indicated that pre-attached denitrifiers in comprehensive communities on stuffing material can be established for the efficient nitrogen and COD removal in aerobic denitrification reactors.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Reatores Biológicos/microbiologia , Bactérias/genética , Biofilmes , Desnitrificação , Nitrogênio/metabolismo , Filogenia , Proteobactérias/classificação , Proteobactérias/genética , Proteobactérias/isolamento & purificação , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/isolamento & purificação , Análise de Sequência de DNA , Águas Residuárias/microbiologia
16.
Sci Rep ; 7(1): 2179, 2017 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-28526844

RESUMO

In soils, phosphorus (P) exists in numerous organic and inorganic forms. However, plants can only acquire inorganic orthophosphate (Pi), meaning global crop production is frequently limited by P availability. To overcome this problem, rock phosphate fertilisers are heavily applied, often with negative environmental and socio-economic consequences. The organic P fraction of soil contains phospholipids that are rapidly degraded resulting in the release of bioavailable Pi. However, the mechanisms behind this process remain unknown. We identified and experimentally confirmed the function of two secreted glycerolphosphodiesterases, GlpQI and GlpQII, found in Pseudomonas stutzeri DSM4166 and Pseudomonas fluorescens SBW25, respectively. A series of co-cultivation experiments revealed that in these Pseudomonas strains, cleavage of glycerolphosphorylcholine and its breakdown product G3P occurs extracellularly allowing other bacteria to benefit from this metabolism. Analyses of metagenomic and metatranscriptomic datasets revealed that this trait is widespread among soil bacteria with Actinobacteria and Proteobacteria, specifically Betaproteobacteria and Gammaproteobacteria, the likely major players.


Assuntos
Diester Fosfórico Hidrolases/metabolismo , Fósforo/metabolismo , Pseudomonas/metabolismo , Microbiologia do Solo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Espaço Extracelular/metabolismo , Metagenoma , Metagenômica/métodos , Modelos Biológicos , Diester Fosfórico Hidrolases/genética , Pseudomonas/classificação , Pseudomonas/genética
17.
Appl Microbiol Biotechnol ; 101(12): 5163-5173, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28299401

RESUMO

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 (A2/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.


Assuntos
Desnitrificação , Bactérias Gram-Negativas/metabolismo , Dodecilsulfato de Sódio/análogos & derivados , Aeromonas/isolamento & purificação , Aeromonas/metabolismo , Biodegradação Ambiental , Carbono/metabolismo , Comamonadaceae/isolamento & purificação , Comamonadaceae/metabolismo , Comamonas/isolamento & purificação , Comamonas/metabolismo , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/isolamento & purificação , Oxirredução , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , Esgotos/microbiologia , Dodecilsulfato de Sódio/química , Dodecilsulfato de Sódio/metabolismo , Tensoativos/química , Tensoativos/metabolismo
18.
J Environ Sci (China) ; 47: 165-173, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27593283

RESUMO

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


Assuntos
Arsênio/metabolismo , Biotransformação , Pseudomonas/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Arsênio/análise , Biodegradação Ambiental , China , Oxirredução , Pseudomonas/classificação , Pseudomonas/genética , Poluentes do Solo/análise
19.
ACS Chem Biol ; 11(6): 1677-85, 2016 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-27045776

RESUMO

Nitrogen cycling is a microbial metabolic process essential for global ecological/agricultural balance. To investigate the link between the well-established ammonium and the alternative nitrate assimilation metabolic pathways, global isotope metabolomics was employed to examine three nitrate reducing bacteria using (15)NO3 as a nitrogen source. In contrast to a control (Pseudomonas stutzeri RCH2), the results show that two of the isolates from Oak Ridge, Tennessee (Pseudomonas N2A2 and N2E2) utilize nitrate and ammonia for assimilation concurrently with differential labeling observed across multiple classes of metabolites including amino acids and nucleotides. The data reveal that the N2A2 and N2E2 strains conserve nitrogen-containing metabolites, indicating that the nitrate assimilation pathway is a conservation mechanism for the assimilation of nitrogen. Co-utilization of nitrate and ammonia is likely an adaption to manage higher levels of nitrite since the denitrification pathways utilized by the N2A2 and N2E2 strains from the Oak Ridge site are predisposed to the accumulation of the toxic nitrite. The use of global isotope metabolomics allowed for this adaptive strategy to be investigated, which would otherwise not have been possible to decipher.


Assuntos
Amônia/metabolismo , Nitratos/metabolismo , Fixação de Nitrogênio , Pseudomonas/metabolismo , Aminoácidos/metabolismo , Biologia Computacional , Desnitrificação , Metabolômica , Radioisótopos de Nitrogênio , Nucleotídeos/biossíntese , Purinas/biossíntese , Purinas/metabolismo , Pirimidinas/biossíntese , Pirimidinas/metabolismo
20.
ISME J ; 10(7): 1568-78, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26771930

RESUMO

Different microbial cell types typically specialize at performing different metabolic processes. A canonical example is substrate cross-feeding, where one cell type consumes a primary substrate into an intermediate and another cell type consumes the intermediate. While substrate cross-feeding is widely observed, its consequences on ecosystem processes is often unclear. How does substrate cross-feeding affect the rate or extent of substrate consumption? We hypothesized that substrate cross-feeding eliminates competition between different enzymes and reduces the accumulation of growth-inhibiting intermediates, thus accelerating substrate consumption. We tested this hypothesis using isogenic mutants of the bacterium Pseudomonas stutzeri that either completely consume nitrate to dinitrogen gas or cross-feed the intermediate nitrite. We demonstrate that nitrite cross-feeding eliminates inter-enzyme competition and, in turn, reduces nitrite accumulation. We further demonstrate that nitrite cross-feeding accelerates substrate consumption, but only when nitrite has growth-inhibiting effects. Knowledge about inter-enzyme competition and the inhibitory effects of intermediates could therefore be important for deciding how to best segregate different metabolic processes into different microbial cell types to optimize a desired biotransformation.


Assuntos
Nitratos/metabolismo , Nitritos/metabolismo , Pseudomonas/metabolismo , Mutação , Pseudomonas/genética
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