RESUMO
The release of pharmaceutical wastewaters in the environment is of great concern due to the presence of persistent organic pollutants with toxic effects on environment and human health. Treatment of these wastewaters with microorganisms has gained increasing attention, as they can efficiently biodegrade and remove contaminants from the aqueous environments. In this respect, bacterial immobilization with inorganic nanoparticles provides a number of advantages, in terms of ease of processing, increased concentration of the pollutant in proximity of the cell surface, and long-term reusability. In the present study, MCM-41 mesoporous silica nanoparticles (MSN) were immobilized on a selected bacterial strain to remove alprazolam, a persistent pharmaceutical compound, from contaminated water. First, biodegrading microorganisms were collected from pharmaceutical wastewater, and Pseudomonas stutzeri was isolated as a bacterial strain showing high ability to tolerate and consume alprazolam as the only source for carbon and energy. Then, the ability of MSN-adhered Pseudomonas stutzeri bacteria was assessed to biodegrade alprazolam using quantitative HPLC analysis. The results indicated that after 20 days in optimum conditions, MSN-adhered bacterial cells achieved 96% biodegradation efficiency in comparison to the 87% biodegradation ability of Pseudomonas stutzeri freely suspended cells. Kinetic study showed that the degradation process obeys a first order reaction. In addition, the kinetic constants for the MSN-adhered bacteria were higher than those of the bacteria alone.
Assuntos
Alprazolam/química , Biodegradação Ambiental , Resíduos Industriais , Nanopartículas , Pseudomonas stutzeri/metabolismo , Águas Residuárias/química , Águas Residuárias/microbiologia , Alprazolam/metabolismo , Humanos , Cinética , Nanotecnologia , Filogenia , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/isolamento & purificação , RNA Ribossômico 16S , TermodinâmicaRESUMO
AIMS: The aim of this study was to find and use rhizobacteria able to confer plants advantages to deal with saline conditions. METHODS AND RESULTS: We isolated 24 different bacterial species from the rhizosphere of halophyte plants growing in Santiago del Estero, Argentina salt flat. Four strains were selected upon their ability to grow in salinity and their biochemical traits associated with plant growth promotion. Next, we tested the adhesion on soybean seeds surface and root colonization with the four selected isolates. Isolate 19 stood out from the rest and was selected for further experiments. This strain showed positive chemotaxis towards soybean root exudates and a remarkable ability to form biofilm both in vitro conditions and on soybean roots. Interestingly, this trait was enhanced in high saline conditions, indicating the extremely adapted nature of the bacterium to high salinity. In addition, this strain positively impacted on seed germination, plant growth and general plant health status also under saline stress. CONCLUSIONS: A bacterium isolate with outstanding ability to promote seed germination and plant growth under saline conditions was found. SIGNIFICANCE AND IMPACT OF THE STUDY: The experimental approach allowed us to find a suitable bacterial candidate for a biofertilizer intended to alleviate saline stress on crops. This would allow the use of soil now considered inadequate for agriculture and thus prevent further advancement of agriculture frontiers into areas of environmental value.
Assuntos
Pseudomonas stutzeri/fisiologia , Rizosfera , Estresse Salino/fisiologia , Argentina , Biofilmes/crescimento & desenvolvimento , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/microbiologia , Germinação , Raízes de Plantas/microbiologia , Pseudomonas stutzeri/crescimento & desenvolvimento , Pseudomonas stutzeri/isolamento & purificação , Salinidade , Plantas Tolerantes a Sal/microbiologia , Sementes/crescimento & desenvolvimento , Sementes/microbiologia , Solo/química , Microbiologia do Solo , Glycine max/crescimento & desenvolvimento , Glycine max/microbiologiaRESUMO
We report a rare case of Pseudomonas stutzeri endophthalmitis in an immunocompetent individual along with the review of the literature. A 39-year-old healthy lady presented with sudden painful loss of vision in her right eye. She was diagnosed with postcataract surgery acute endophthalmitis and underwent vitrectomy, intraocular lens explantation and intravitreal antibiotics. P. stutzeri was isolated from vitreous. Though the infection was controlled, the anatomy of the eye could not be salvaged and the right eye became phthisical. P. stutzeri is a rare cause of endophthalmitis with usually poor outcomes.
Assuntos
Extração de Catarata/efeitos adversos , Endoftalmite/etiologia , Infecções por Pseudomonas/etiologia , Pseudomonas stutzeri/isolamento & purificação , Adulto , Endoftalmite/diagnóstico , Endoftalmite/microbiologia , Infecções Oculares Bacterianas , Feminino , Humanos , Infecções por Pseudomonas/diagnóstico , Infecções por Pseudomonas/microbiologiaRESUMO
We report a case of Pseudomonas stutzeri endocarditis in Lebanon. The patient had a recent history of prosthetic aortic valve replacement and presented to the emergency department with fever and chills. Transesophageal echocardiography confirmed the presence of a vegetation on the prosthetic valve and blood cultures yielded P. stutzeri. The patient was treated with surgery and antibiotics but deteriorated and passed away four days after admission. To our knowledge, this is the fifth case of P. stutzeri endocarditis reported in the literature, and the first case with early presentation and mortality.
Assuntos
Valva Aórtica , Endocardite Bacteriana/diagnóstico , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas/efeitos adversos , Pseudomonas stutzeri/isolamento & purificação , Idoso , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Ceftazidima/administração & dosagem , Ceftazidima/uso terapêutico , Calafrios/etiologia , Diagnóstico Diferencial , Ecocardiografia Transesofagiana , Endocardite Bacteriana/complicações , Endocardite Bacteriana/diagnóstico por imagem , Endocardite Bacteriana/tratamento farmacológico , Humanos , Infusões Intravenosas , Masculino , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/tratamento farmacológico , Infecções Relacionadas à Prótese/complicações , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/diagnóstico por imagem , Infecções Relacionadas à Prótese/tratamento farmacológicoRESUMO
An efficient aerobic denitrifying bacterium was isolated from the sediments of the Jin Pen Reservoir in Xi'an. The strain was identified by morphological features and 16S rDNA sequences as Pseudomonas stutzeri and named it KK99. The denitrification characteristics of the strain and the expression level of the functional genes narG, nirS, and nosZ in aerobic/anaerobic conditions were investigated. The results showed that the strain can carry out both anaerobic and aerobic denitrification and has a high efficiency of denitrification, which occurs under both aerobic and anaerobic conditions; after 24 h, the removal rates of total nitrogen (TN) were 85.08% and 89.05%, respectively. Under both the conditions, the expression levels of the functional genes nosZ and nirS are high. nosZ plays a vital role in denitrification in the aerobic pathway, nirS plays a vital role in denitrification in the anaerobic pathway, and narG expression is low under both the conditions. At the same time, simultaneous nitrification and denitrification (SND) capacity of the strain was observed when nitrate and ammonium salts were the nitrogen sources, with the total nitrogen removal rate being 76% within 24 h in aerobic conditions. The P. stutzeri KK99 strain can be used for controlling eutrophication of micro-polluted water, and the application of total nitrogen reduction engineering.
Assuntos
Desnitrificação , Genes Bacterianos , Pseudomonas stutzeri/genética , Aerobiose , China , Sedimentos Geológicos/microbiologia , Nitrificação , Nitrogênio , Pseudomonas stutzeri/isolamento & purificação , Microbiologia da ÁguaRESUMO
AD-1, an aerobic denitrifier, was isolated from activated sludge and identified as Pseudomonas stutzeri. AD-1 completely removed NO3- or NO2- and removed 99.5% of NH4+ during individual culturing in a broth medium with an initial nitrogen concentration of approximately 50 mg L-1. Results showed that larger amounts of nitrogen were removed through assimilation by the bacteria. And when NH4+ was used as the sole nitrogen source in the culture medium, neither NO2- nor NO3- was detected, thus indicating that AD-1 may not be a heterotrophic nitrifier. Only trace amount of N2O was detected during the denitrification process. Single factor experiments indicated that the optimal culture conditions for AD-1 were: a carbon-nitrogen ratio (C/N) of 15, a temperature of 25°C and sodium succinate or glucose as a carbon source. In conclusion, due to the ability of AD-1 to utilize nitrogen of different forms with high efficiencies for its growth while producing only trace emissions of N2O, the bacterium had outstanding potential to use in the bioremediation of high-nitrogen-containing wastewaters. Meanwhile, it may also be a proper candidate for biotreatment of high concentration organic wastewater.
Assuntos
Desnitrificação , Nitrogênio/isolamento & purificação , Nitrogênio/metabolismo , Pseudomonas stutzeri/metabolismo , Purificação da Água/métodos , Aerobiose , Biodegradação Ambiental , Carbono/química , Carbono/metabolismo , Processos Heterotróficos , Humanos , Pseudomonas stutzeri/isolamento & purificação , Esgotos/química , Esgotos/microbiologia , Temperatura , Águas Residuárias/químicaRESUMO
ABSTRACT Discharge of coke-oven wastewater to the environment may cause severe contamination to it and also threaten the flora and fauna, including human beings. Hence before dumping it is necessary to treat this dangerous effluent in order to minimize the damage to the environment. Conventional technologies have inherent drawbacks however, biological treatment is an advantageous alternative method. In the present study, bacteria were isolated from the soil collected from the sites contaminated by coke-oven effluent rich in phenol and cyanide. Nucleotides sequence alignment and phylogenetic analysis showed the identity of the selected phenol and cyanide degrading isolates NAUN-16 and NAUN-1B as Pseudomonas putida and Pseudomonas stutzeri, respectively. These two isolates tolerated phenol up to 1800 mg L-1 and cyanide up to 340 mg L-1 concentrations. The isolates were immobilized on activated charcoal, saw dust and fly ash. The effluent was passed through the column packed with immobilized cells with a flow rate of 5 mL min-1. The isolates showed degradation of phenol up to 80.5% and cyanide up to 80.6% and also had the ability to reduce biological oxygen demand, chemical oxygen demand and lower the pH of effluent from alkaline to near neutral. The study suggests the utilization of such potential bacterial strains in treating industrial effluent containing phenol and cyanide, before being thrown in any ecosystem.
Assuntos
Cianetos/metabolismo , Fenol/metabolismo , Pseudomonas putida/metabolismo , Pseudomonas stutzeri/metabolismo , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Biodegradação Ambiental , Células Imobilizadas/classificação , Células Imobilizadas/metabolismo , Coque/análise , Cianetos/análise , Resíduos Industriais/análise , Fenol/análise , Filogenia , Pseudomonas putida/classificação , Pseudomonas putida/genética , Pseudomonas putida/isolamento & purificação , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/isolamento & purificação , Águas Residuárias/análiseRESUMO
Discharge of coke-oven wastewater to the environment may cause severe contamination to it and also threaten the flora and fauna, including human beings. Hence before dumping it is necessary to treat this dangerous effluent in order to minimize the damage to the environment. Conventional technologies have inherent drawbacks however, biological treatment is an advantageous alternative method. In the present study, bacteria were isolated from the soil collected from the sites contaminated by coke-oven effluent rich in phenol and cyanide. Nucleotides sequence alignment and phylogenetic analysis showed the identity of the selected phenol and cyanide degrading isolates NAUN-16 and NAUN-1B as Pseudomonas putida and Pseudomonas stutzeri, respectively. These two isolates tolerated phenol up to 1800mgL-1 and cyanide up to 340mgL-1 concentrations. The isolates were immobilized on activated charcoal, saw dust and fly ash. The effluent was passed through the column packed with immobilized cells with a flow rate of 5mLmin-1. The isolates showed degradation of phenol up to 80.5% and cyanide up to 80.6% and also had the ability to reduce biological oxygen demand, chemical oxygen demand and lower the pH of effluent from alkaline to near neutral. The study suggests the utilization of such potential bacterial strains in treating industrial effluent containing phenol and cyanide, before being thrown in any ecosystem.
Assuntos
Cianetos/metabolismo , Fenol/metabolismo , Pseudomonas putida/metabolismo , Pseudomonas stutzeri/metabolismo , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Biodegradação Ambiental , Células Imobilizadas/classificação , Células Imobilizadas/metabolismo , Coque/análise , Cianetos/análise , Resíduos Industriais/análise , Fenol/análise , Filogenia , Pseudomonas putida/classificação , Pseudomonas putida/genética , Pseudomonas putida/isolamento & purificação , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/isolamento & purificação , Águas Residuárias/análiseRESUMO
This study describes a novel and efficient alasan-like bioemulsifier produced by Pseudomonas stutzeri NJtech 11-1, which was isolated from the Shengli Oilfield. The strain was found to produce a new and interesting emulsion stabilizer. The crude bioemulsifier showed super stability with 50% salinity and broad pH 3-10. The emulsion index (EI24) was increased to 100% after heating from 45 to 95 °C and the emulsion could be stable for at least 30 days. The yield of Ps-bioemulsifier (pure bioemulsifier) was 0.68 ± 0.05 mg mL-1. The Ps-bioemulsifier was composed of carbohydrates (80 ± 2.6%) and proteins (9.5 ± 0.5%). A low concentration (0.2 mg mL-1) of the Ps-bioemulsifier was obtained maximum emulsifying activity at pH 7.1 and its emulsifying activity strengthened by suitable salinity. Furthermore, Ps-bioemulsifier could also emulsify cyclohexane, hexadecane, kerosene, xylene hydrocarbons efficiently. Therefore, the Ps-bioemulsifier showed emulsifying characteristics which make it a good candidate for potential applications in bioremediation and microbial enhanced oil recovery.
Assuntos
Emulsificantes/isolamento & purificação , Emulsificantes/metabolismo , Pseudomonas stutzeri/metabolismo , Alcanos/metabolismo , Biodegradação Ambiental , Metabolismo dos Carboidratos , Cicloexanos/metabolismo , Endopeptidase K , Hidrocarbonetos/metabolismo , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Querosene , Petróleo/metabolismo , Filogenia , Proteínas/metabolismo , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/crescimento & desenvolvimento , Pseudomonas stutzeri/isolamento & purificação , Salinidade , Temperatura , ViscosidadeRESUMO
The partial structure and immunology of the lipopolysaccharide (LPS) of Pseudomonas stutzeri KMM 226, a bacterium isolated from a seawater sample collected at a depth of 2000 m, was characterised. The O-polysaccharide was built up of disaccharide repeating units constituted by L-Rhap and D-GlcpNAc: â2)-α-L-Rhap-(1â3)-α-D-GlcpNAc-(1â. The structural analysis of the lipid A showed a mixture of different species. The major species were hexa-acylated and penta-acylated lipids A, bearing the 12:0(3-OH) in amide linkage and 10:0(3-OH) in ester linkage, while the secondary fatty acids were present only as 12:0. The presence of 12:0(2-OH) was not detected. The immunology experiments demonstrated that P. stutzeri KMM 226 LPS displayed a low ability to induce TNF-α, IL-1ß, IL-6, IL-8 and IL-10 cytokine production and acted as an antagonist of hexa-acylated Escherichia coli LPS in human blood in vitro.
Assuntos
Lipopolissacarídeos/imunologia , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/imunologia , Água do Mar/microbiologia , Microbiologia da Água , Citocinas/sangue , Citocinas/metabolismo , Humanos , Lipídeo A/química , Lipídeo A/imunologia , Lipopolissacarídeos/química , Espectroscopia de Ressonância Magnética , Antígenos O/química , Antígenos O/imunologia , Infecções por Pseudomonas/sangue , Infecções por Pseudomonas/imunologia , Infecções por Pseudomonas/metabolismo , Pseudomonas stutzeri/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
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/microbiologiaAssuntos
Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana , Integrons , Infecções por Pseudomonas/microbiologia , Pseudomonas stutzeri/enzimologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Humanos , Integrases/genética , Integrases/metabolismo , Testes de Sensibilidade Microbiana , Infecções Oportunistas/microbiologia , Ligação Proteica , Pseudomonas stutzeri/efeitos dos fármacos , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/isolamento & purificação , beta-Lactamases/genética , beta-Lactamases/metabolismoRESUMO
Pseudomonas stutzeri se encuentra ampliamente distribuido en el medio ambiente, ocupando diversos nichos ecológicos; pero su aparición en procesos infecciosos de interés clínico es el de patógeno oportunista. El aislamiento de P. stutzeri en un quiste inflamatorio odontogénico es un verdadero hallazgo microbiológico que no presenta antecedentes en la bibliografía científica odontológica. En este caso particular, el aislamiento se obtuvo a partir de material quirúrgico proveniente de un quiste odontogénico inflamatorio ubicado en la pieza dentaria 1.2 con necrosis pulpar concomitante. Se emplearon técnicas diagnósticas complementarias como radiografías, tomografías, estudios anatomopatológicos y microbiológicos. Los resultados permitieron clasificar el proceso como quiste inflamatorio infectado con P. stutzeri. La tipificación y la caracterización del perfil de sensibilidad de la cepa aislada permitieron adecuar la terapéutica antibiótica de manera específica. El análisis microbiológico permitió establecer la etiología del proceso infeccioso, la adecuación del tratamiento y el restablecimiento de los tejidos comprometidos.
Pseudomonas stutzeri is distributed widely in the environment, and occupies different ecological niches. However, it is found in clinically relevant infections as an opportunistic pathogen. Isolation of P. stutzeri from an odontogenic inflammatory cyst is an uncommon microbiological finding that has not been reported to date. In the case presented here, the bacterium was isolated from surgical material obtained from excision of an inflammatory odontogenic cyst located in the tooth 1.2, and presenting with concomitant pulp necrosis. Complementary techniques such as radiographs, CAT scans, and histopathological and microbiological studies were used to establish definitive diagnosis. The obtained results allowed classifying the process as an inflammatory cyst infected by P. stutzeri. Biotyping and characterization of the susceptibility profile of the isolated strain allowed adjusting the antibiotic therapy more specifically. The microbiological studies allowed establishing the etiology of the infectious process, adjusting the treatment plan, and re-establishing tissue integrity.
Assuntos
Humanos , Feminino , Adulto , Infecções Oportunistas/terapia , Cistos Odontogênicos/cirurgia , Cistos Odontogênicos/diagnóstico , Cistos Odontogênicos/microbiologia , Pseudomonas stutzeri/isolamento & purificação , Técnicas Microbiológicas/métodos , Necrose da Polpa Dentária/complicações , Pseudomonas stutzeri/patogenicidadeRESUMO
Pseudomonas stutzeri is distributed widely in the environment, and occupies different ecological niches. However, it is found in clinically relevant infections as an opportunistic pathogen. Isolation of P. stutzeri from an odontogenic inflammatory cyst is an uncommon microbiological finding that has not been reported to date. In the case presented here, the bacterium was isolated from surgical material obtained from excision of an inflammatory odontogenic cyst located in the tooth 1.2, and presenting with concomitant pulp necrosis. Complementary techniques such as radiographs, CAT scans, and histopathological and microbiological studies were used to establish definitive diagnosis. The obtained results allowed classifying the process as an inflammatory cyst infected by P. stutzeri. Biotyping and characterization of the susceptibility profile of the isolated strain allowed adjusting the antibiotic therapy more specifically. The microbiological studies allowed establishing the etiology of the infectious process, adjusting the treatment plan, and re-establishing tissue integrity.
Assuntos
Cistos Odontogênicos , Infecções por Pseudomonas , Pseudomonas stutzeri , Antibacterianos/uso terapêutico , Humanos , Cistos Odontogênicos/microbiologia , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas stutzeri/isolamento & purificaçãoRESUMO
An extracellular organic solvent-tolerant lipase-producing bacterium was isolated from oil-contaminated soil samples and was identified taxonomically as Pseudomonas stutzeri, from which the lipase was purified and exhibited maximal activity at temperature of 50 °C and pH of 9.0. Meanwhile, the lipase was stable below or at 30 °C and over an alkaline pH range (7.5-11.0). Ca2+ could significantly improve the lipase thermal stability which prompts a promising application in biocatalysis through convenient medium engineering. The lipase demonstrated striking features such as distinct stability to the most tested hydrophilic and hydrophobic solvents (25 %, v/v), and DMSO could activate the lipase dramatically. In the enzyme-catalyzed resolution, lipase ZS04 manifested excellent enantioselective esterification toward the (R)-1-(4-methoxyphenyl)-ethanol (MOPE), a crucial chiral intermediate in pharmaceuticals as well as in other analogs with strict substrate specificity and theoretical highest conversion yield. This strong advantage over other related schemes made lipase ZS04 a promising biocatalyst in organic synthesis and pharmaceutical applications.
Assuntos
Álcoois/química , Cálcio/farmacologia , Lipase/metabolismo , Pseudomonas stutzeri/enzimologia , Detergentes/farmacologia , Eletroforese em Gel de Poliacrilamida , Inibidores Enzimáticos/farmacologia , Estabilidade Enzimática/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Íons , Lipase/isolamento & purificação , Pseudomonas stutzeri/efeitos dos fármacos , Pseudomonas stutzeri/isolamento & purificação , Solventes , Especificidade por Substrato/efeitos dos fármacos , TemperaturaRESUMO
Three bacterial isolates identified as Alcanivorax borkumensis SK2, Rhodococcus erythropolis HS4 and Pseudomonas stutzeri SDM, based on 16S rRNA gene sequences, were isolated from crude oil enrichments of natural seawater. Single strains and four bacterial consortia designed by mixing the single bacterial cultures respectively in the following ratios: (Alcanivorax: Pseudomonas, 1:1), (Alcanivorax: Rhodococcus, 1:1), (Pseudomonas: Rhodococcus, 1:1), and (Alcanivorax: Pseudomonas: Rhodococcus, 1:1:1), were analyzed in order to evaluate their oil degrading capability. All experiments were carried out in microcosms systems containing seawater (with and without addition of inorganic nutrients) and crude oil (unique carbon source). Measures of total and live bacterial abundance, Card-FISH and quali-, quantitative analysis of hydrocarbons (GC-FID) were carried out in order to elucidate the co-operative action of mixed microbial populations in the process of biodegradation of crude oil. All data obtained confirmed the fundamental role of bacteria belonging to Alcanivorax genus in the degradation of linear hydrocarbons in oil polluted environments.
Assuntos
Alcanivoraceae/metabolismo , Petróleo/metabolismo , Pseudomonas stutzeri/metabolismo , Rhodococcus/metabolismo , Alcanivoraceae/classificação , Alcanivoraceae/genética , Alcanivoraceae/isolamento & purificação , Biotransformação , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Consórcios Microbianos , Dados de Sequência Molecular , Filogenia , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/isolamento & purificação , RNA Ribossômico 16S/genética , Rhodococcus/classificação , Rhodococcus/genética , Rhodococcus/isolamento & purificação , Água do Mar/microbiologia , Análise de Sequência de DNARESUMO
An aerobic denitrifier, identified as Pseudomonas stutzeri strain ZF31, was isolated from the Zhoucun drinking-water reservoir. Strain ZF31 removed 97% of nitrate nitrogen after 16h, without nitrite accumulation. Sequence amplification indicated the presence of the denitrification genes napA, nirS, norB, and nosZ. Nitrogen balance analysis revealed that approximately 75% of the initial nitrogen was removed as gas products. Response surface methodology (RSM) experiments showed that maximum removal of total nitrogen (TN) occurred at pH 8.23, a C/N ratio of 6.68, temperature of 27.72°C, and with shaking at 54.15rpm. The TN removal rate at low C/N ratio (i.e., 3) and low temperature (i.e., 10°C) was 73.30% and 60.08%, respectively. These results suggest that strain ZF31 has potential applications for the bioremediation of slightly polluted drinking-water reservoirs.
Assuntos
Desnitrificação , Nitratos/metabolismo , Nitrogênio/metabolismo , Pseudomonas stutzeri/enzimologia , Aerobiose , Biodegradação Ambiental , Água Potável/microbiologia , Modelos Químicos , Nitratos/análise , Nitritos/análise , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/isolamento & purificaçãoRESUMO
UNLABELLED: The ability to reduce atmospheric nitrogen (N2) to ammonia, known as N2 fixation, is a widely distributed trait among prokaryotes that accounts for an essential input of new N to a multitude of environments. Nitrogenase reductase gene (nifH) composition suggests that putative N2-fixing heterotrophic organisms are widespread in marine bacterioplankton, but their autecology and ecological significance are unknown. Here, we report genomic and ecophysiology data in relation to N2 fixation by three environmentally relevant heterotrophic bacteria isolated from Baltic Sea surface water: Pseudomonas stutzeri strain BAL361 and Raoultella ornithinolytica strain BAL286, which are gammaproteobacteria, and Rhodopseudomonas palustris strain BAL398, an alphaproteobacterium. Genome sequencing revealed that all were metabolically versatile and that the gene clusters encoding the N2 fixation complex varied in length and complexity between isolates. All three isolates could sustain growth by N2 fixation in the absence of reactive N, and this fixation was stimulated by low concentrations of oxygen in all three organisms (≈ 4 to 40 µmol O2 liter(-1)). P. stutzeri BAL361 did, however, fix N at up to 165 µmol O2 liter(-1), presumably accommodated through aggregate formation. Glucose stimulated N2 fixation in general, and reactive N repressed N2 fixation, except that ammonium (NH4 (+)) stimulated N2 fixation in R. palustris BAL398, indicating the use of nitrogenase as an electron sink. The lack of correlations between nitrogenase reductase gene expression and ethylene (C2H4) production indicated tight posttranscriptional-level control. The N2 fixation rates obtained suggested that, given the right conditions, these heterotrophic diazotrophs could contribute significantly to in situ rates. IMPORTANCE: The biological process of importing atmospheric N2 is of paramount importance in terrestrial and aquatic ecosystems. In the oceans, a diverse array of prokaryotes seemingly carry the genetic capacity to perform this process, but lack of knowledge about their autecology and the factors that constrain their N2 fixation hamper an understanding of their ecological importance in marine waters. The present study documents a high variability of genomic and ecophysiological properties related to N2 fixation in three heterotrophic isolates obtained from estuarine surface waters and shows that these organisms fix N2 under a surprisingly broad range of conditions and at significant rates. The observed intricate regulation of N2 fixation for the isolates indicates that indigenous populations of heterotrophic diazotrophs have discrete strategies to cope with environmental controls of N2 fixation. Hence, community-level generalizations about the regulation of N2 fixation in marine heterotrophic bacterioplankton may be problematic.
Assuntos
Enterobacteriaceae/isolamento & purificação , Processos Heterotróficos , Fixação de Nitrogênio , Pseudomonas stutzeri/isolamento & purificação , Rodopseudomonas/isolamento & purificação , Água do Mar/microbiologia , DNA Bacteriano/química , DNA Bacteriano/genética , Enterobacteriaceae/genética , Enterobacteriaceae/metabolismo , Regulação Bacteriana da Expressão Gênica , Variação Genética , Genoma Bacteriano , Glucose/metabolismo , Dados de Sequência Molecular , Família Multigênica , Nitrogênio/metabolismo , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/metabolismo , Rodopseudomonas/genética , Rodopseudomonas/metabolismo , Análise de Sequência de DNARESUMO
Three bacterial isolates identified as Alcanivorax borkumensis SK2, Rhodococcus erythropolis HS4 and Pseudomonas stutzeri SDM, based on 16S rRNA gene sequences, were isolated from crude oil enrichments of natural seawater. Single strains and four bacterial consortia designed by mixing the single bacterial cultures respectively in the following ratios: (Alcanivorax: Pseudomonas, 1:1), (Alcanivorax: Rhodococcus, 1:1), (Pseudomonas: Rhodococcus, 1:1), and (Alcanivorax: Pseudomonas: Rhodococcus, 1:1:1), were analyzed in order to evaluate their oil degrading capability. All experiments were carried out in microcosms systems containing seawater (with and without addition of inorganic nutrients) and crude oil (unique carbon source). Measures of total and live bacterial abundance, Card-FISH and quali-, quantitative analysis of hydrocarbons (GC-FID) were carried out in order to elucidate the co-operative action of mixed microbial populations in the process of biodegradation of crude oil. All data obtained confirmed the fundamental role of bacteria belonging to Alcanivorax genus in the degradation of linear hydrocarbons in oil polluted environments.
Assuntos
Alcanivoraceae/metabolismo , Petróleo/metabolismo , Pseudomonas stutzeri/metabolismo , Rhodococcus/metabolismo , Alcanivoraceae/classificação , Alcanivoraceae/genética , Alcanivoraceae/isolamento & purificação , Biotransformação , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Consórcios Microbianos , Dados de Sequência Molecular , Filogenia , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/isolamento & purificação , /genética , Rhodococcus/classificação , Rhodococcus/genética , Rhodococcus/isolamento & purificação , Análise de Sequência de DNA , Água do Mar/microbiologiaRESUMO
A 25-year-old woman underwent intracranial surgery for trigeminal nerve schwannoma (TGNS) with persistent left-sided facial hypoaesthesia. Two months later, she developed a central corneal ulceration. Scraping of the corneal lesion revealed Gram-negative bacilli. Genus level identification was achieved using standard techniques and species level identification, revealing Pseudomonas stutzeri, was aided by a VITEK 2 compact system. Broad-spectrum fortified antibiotics were initially started followed by species-sensitive fortified antibiotics. Ocular surface toxicity developed a week later; this was managed with a non-fortified antibiotic. The epithelial defect healed in 3 weeks with subsequent corneal scar formation. Visual rehabilitation was achieved with deep anterior lamellar keratoplasty. Six months following surgery, the patient had a visual acuity of 20/40 with -1.25 170° -0.5 refractive correction and a clear graft. This case report, for the first time, highlights P. stutzeri, an aetiological agent of corneal ulcer following excision of TGNS and its successful management.