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Bacillus safensis strain WOIS2, a nitrile-metabolizing bacterium, was isolated from solid waste leachates at the Olusosun dumpsite, Ojota, Lagos State, Nigeria. Here, we present the draft genome sequence of strain WOIS2. These data provide valuable information on the bioprospecting of B. safensis nitrilase and other intriguing genes of interest.
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Bacillus safensis strain WOB7 is a linamarin-utilizing bacterium (LUB) that was isolated from cassava wastewater obtained from a processing factory. We present here the draft genome sequence of the strain (WOB7). These data provide valuable information on the prospects of the linamarase and other genes of importance associated with cyanogen detoxification.
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The impacts of hexavalent chromium (Cr) contamination on the microbiome, soil physicochemistry, and heavy metal resistome of a tropical agricultural soil were evaluated for 6 weeks in field-moist microcosms consisting of a Cr-inundated agricultural soil (SL9) and an untreated control (SL7). The physicochemistry of the two microcosms revealed a diminution in the total organic matter content and a significant dip in macronutrients phosphorus, potassium, and nitrogen concentration in the SL9 microcosm. Heavy metals analysis revealed the detection of seven heavy metals (Zn, Cu, Fe, Cd, Se, Pb, Cr) in the agricultural soil (SL7), whose concentrations drastically reduced in the SL9 microcosm. Illumina shotgun sequencing of the DNA extracted from the two microcosms showed the preponderance of the phyla, classes, genera, and species of Actinobacteria (33.11%), Actinobacteria_class (38.20%), Candidatus Saccharimonas (11.67%), and Candidatus Saccharimonas aalborgensis (19.70%) in SL7, and Proteobacteria (47.52%), Betaproteobacteria (22.88%), Staphylococcus (16.18%), Staphylococcus aureus (9.76%) in SL9, respectively. Functional annotation of the two metagenomes for heavy metal resistance genes revealed diverse heavy metal resistomes involved in the uptake, transport, efflux, and detoxification of various heavy metals. It also revealed the exclusive detection in SL9 metagenome of resistance genes for chromium (chrB, chrF, chrR, nfsA, yieF), cadmium (czcB/czrB, czcD), and iron (fbpB, yqjH, rcnA, fetB, bfrA, fecE) not annotated in SL7 metagenome. The findings from this study revealed that Cr contamination induces significant shifts in the soil microbiome and heavy metal resistome, alters the soil physicochemistry, and facilitates the loss of prominent members of the microbiome not adapted to Cr stress.
Assuntos
Metais Pesados , Microbiota , Poluentes do Solo , Solo/química , Poluentes do Solo/análise , Metais Pesados/toxicidade , Metais Pesados/análise , Cromo/toxicidade , Cromo/análise , Cádmio/análise , Monitoramento Ambiental , ChinaRESUMO
The coexistence of heavy metals (HMs) and petroleum hydrocarbons (PHs) exacerbates ecotoxicity and impair the drivers of eco-functionalities that stimulate essential nutrients for the productivity of the impacted environment. Profiling the bacteria that stem the ecological impact via HMs sequestration and PHs catabolism with nitrogen fixation is imperative to bioremediation of the polluted sites. The sediment of site that was consistently contaminated with industrial wastewaters was analysed for ecological toxicants and the bacterial strains that combined HMs resistance with PHs catabolism in a nitrogen-limiting system were isolated from the sediment and characterized. The geochemistry of the samples revealed the co-occurrence of the above-benchmark concentrations of HMs with the derivatives of hydrocarbons. Notwithstanding, nickel and mercury (with 5% each of the total metal concentrations in the polluted site) exhibited probable effect concentrations on the biota and thus hazardous to the ecosystem. Approx. 31% of the bacterial community, comprising unclassified Planococcaceae, unclassified Bradyrhizobiaceae, Rhodococcus, and Bacillus species, resisted 160 µmol Hg2+ in the nitrogen-limiting system within 24 h post-inoculation. The bacterial strains adopt volatilization, and sometimes in combination with adsorption/bioaccumulation strategies to sequester Hg2+ toxicity while utilizing PHs as sources of carbon and energy. Efficient metabolism of petroleum biomarkers (> 87%) and Hg2+ sequestration (≥ 75% of 40 µmol Hg2+) displayed by the selected bacterial strains portend the potential applicability of the bacilli for biotechnological restoration of the polluted site.
Assuntos
Bacillus , Mercúrio , Metais Pesados , Petróleo , Petróleo/metabolismo , Águas Residuárias , Ecossistema , Metais Pesados/metabolismo , Bactérias/genética , Bactérias/metabolismo , Biodegradação Ambiental , Hidrocarbonetos/metabolismo , Bacillus/metabolismoRESUMO
A limited number of Bacillus amyloliquefaciens genome sequences have been generated and are available in the public domain from soil, fermented foods, and plants. Here, we report the whole-genome sequence of B. amyloliquefaciens AD20, isolated from a dye pond with azo dye decolorization capabilities.
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Trans-Atlantic voyage of petroleum often leads to marine pollution with petroleum hydrocarbons (PHs) and heavy metals (HMs) that defines structures of autochthonous bacteria in the hydrosphere. Bacterial taxa of marine sediments exposed to petroleum transport activities were profiled using 16S rDNA metagenomics and correlated with the geochemistry to establish their impact on the microbiome. The physico-chemistry of the marine systems revealed varied degrees of contamination with PHs and HMs exceeding recommended threshold for aquatic life. Ecological risk assessment based on organic carbon of the sediment established phenanthrene, anthracene, and pyrene posed high risks (index risk quotient >32) to marine life. The most dominant phylum of the 44 bacterial phyla in the marine-sphere was Proteobacteria with relative abundance of 45-77% in the sampling locations. Relative dominance of Proteobacteria in the sediments spanned Gammaproteobacteria (17-25%), Deltaproteobacteria (12-20%), and Alphaproteobacteria (7-14%). Whereas, more operational taxonomic units (OTUs) belonging to Epsilonproteobacteria (19 ± 2.4%) were found in estuarine sediment unlike < 0.5% relative abundances obtained from oceanic sediments. Sulfurimonas apparently dominated the bacterial genera with up to 2.16 ± 0.19% abundance in oceanic sediments. Canonical correspondence analysis revealed that PHs shaped the structure of bacterial OTUs in oceanic sediments where petroleum loading/offloading occurs unlike in some kilometres a yonder where HMs correlated with the bacteria structure. The dominant bacteria might possibly pivotal to ecophysiologies of hydrocarbon contaminated marine environment, and would be pertinent to biotechnological applications for possible bioremediation campaign.
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Metais Pesados , Poluição por Petróleo , Petróleo , Oceano Atlântico , Bactérias/genética , Sedimentos Geológicos , Hidrocarbonetos/análise , Metais Pesados/toxicidade , Nigéria , Oceanos e Mares , RNA Ribossômico 16S/genéticaRESUMO
Toxic metals/metalloid contaminations of estuarine sediments due to compromised tributaries arouse significant interest in studying bacterial community that triggers natural attenuation processes. Geo-accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), and Hakanson potential ecological risk index (RI) as a sum of risk factors (Er) were used to quantify toxic metal/metalloid-pollution status of Lagos Lagoon (2W) and 'Iya-Alaro' tributary (4W) sediments in comparison with pristine 'Lekki Conservation Centre' sediment (L1-B). Bacteriology of the ecosystems was based on culture-independent analyses using pyrosequencing. 2W and 4W were extremely contaminated with mercury (Igeoâ¯>â¯7), whereas, cadmium contamination was only observed in 4W. The two ecosystems were polluted with toxic metal based on PLI, where mercury (Erâ¯=â¯2900 and 1900 for 4W and 2W, respectively) posed very high ecological risks. Molecular fingerprinting revealed that Proteobacteria, Firmicutes, and Acidobacteria predominately contributed the 20 most abundant genera in the two ecosystems. The 240 and 310 species present in 2W and 4W, respectively, but absent in L1-B, thrive under the metal concentrations in the polluted hydrosphere. Whereas, the 58,000 species missing in 2W and 4W but found in L1-B would serve as indicators for systems impacted with metal eco-toxicity. Despite toxic metal pollution of the ecosystems understudied, bacterial communities play vital roles in self-recovery processes occurring in the hydrosphere.
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Monitoramento Ambiental/métodos , Estuários , Sedimentos Geológicos/microbiologia , Metais Pesados/análise , Microbiota , Poluentes Químicos da Água/análise , Acidobacteria/isolamento & purificação , Ecossistema , Firmicutes/isolamento & purificação , Sedimentos Geológicos/química , Nigéria , Proteobactérias/isolamento & purificaçãoRESUMO
The bacterial community structure in a hydrocarbon-contaminated Mechanical Engineering Workshop (MWO) soil was deciphered using 16S rRNA gene clone library analysis. Four hundred and thirty-seven clones cutting across 13 bacterial phyla were recovered from the soil. The representative bacterial phyla identified from MWO soil are Proteobacteria, Bacteroidetes, Chloroflexi, Acidobacteria, Firmicutes, Actinobacteria, Verrucomicrobia, Planctomycetes, Ignavibacteriae, Spirochaetes, Chlamydiae, Candidatus Saccharibacteria and Parcubacteria. Proteobacteria is preponderant in the contaminated soil (51.2%) with all classes except Epsilonproteobacteria duly represented. Rarefaction analysis indicates 42%, 52% and 77% of the clone library is covered at the species, genus and family/class delineations with Shannon diversity (H') and Chao1 richness indices of 5.59 and 1126, respectively. A sizeable number of bacterial phylotypes in the clone library shared high similarities with strains previously described to be involved in hydrocarbon biodegradation. Novel uncultured genera were identified that have not been previously reported from tropical African soil to be associated with natural attenuation of hydrocarbon pollutants. This study establishes the involvement of a wide array of physiologically diverse bacterial groups in natural attenuation of hydrocarbon pollutants in soil.
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Hidrocarbonetos/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade , Bactérias , Biodiversidade , DNA Bacteriano , Filogenia , RNA Ribossômico 16S , SoloRESUMO
The last two decades had witnessed extensive investigation on bacterial degradation of carbazole, an N-heterocyclic aromatic hydrocarbon. Specifically, previous studies have reported the primary importance of angular dioxygenation, a novel type of oxygenation reaction, which facilitates mineralization of carbazole to intermediates of the TCA cycle. Proteobacteria and Actinobacteria are the predominant bacterial phyla implicated in this novel mode of dioxygenation, while anthranilic acid and catechol are the signature metabolites. Several studies have elucidated the degradative genes involved, the diversity of the car gene clusters and the unique organization of the car gene clusters in marine carbazole degraders. However, there is paucity of information regarding the environmental fate as well as industrial and medical importance of carbazole and its derivatives. In this review, attempt is made to harness this information to present a comprehensive outlook that not only focuses on carbazole biodegradation pathways, but also on its environmental fate as well as medical and industrial importance of carbazole and its derivatives.
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Coastal sediments contaminated by polycyclic aromatic hydrocarbons (PAHs) can be candidates for remediation via an approach like land farming. Land farming converts naturally anaerobic sediments to aerobic environments, and the response of microbial communities, in terms of community structure alterations and corresponding effects on biodegradative activities, is unknown. A key goal of this study was to determine if different sediments exhibited common patterns in microbial community responses that might serve as indicators of PAH biodegradation. Sediments from three stations in the Lagos Lagoon (Nigeria) were used in microcosms, which were spiked with a mixture of four PAH, then examined for PAH biodegradation and for shifts in microbial community structure by analysis of diversity in PAH degradation genes and Illumina sequencing of 16S rRNA genes. PAH biodegradation was similar in all sediments, yet each exhibited unique microbiological responses and there were no microbial indicators of PAH bioremediation common to all sediments.
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Biodegradação Ambiental , Estuários , Sedimentos Geológicos/microbiologia , Consórcios Microbianos/fisiologia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes Químicos da Água/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Consórcios Microbianos/genética , Nigéria , Fenantrenos/metabolismo , Pirenos/metabolismo , RNA Ribossômico 16S/genética , Poluentes do Solo/metabolismoRESUMO
ABSTRACT The goal of this investigation was to isolate competent polynuclear aromatic hydrocarbons degraders that can utilize polynuclear aromatic hydrocarbons of former industrial sites at McDoel Switchyard in Bloomington, Indiana. Using conventional enrichment method based on soil slurry, we isolated, screened and purified two bacterial species strains PB1 and PB2. Applying the ribotyping technique using the 16S rRNA gene analysis, the strains were assigned to the genus Pseudomonas (Pseudomonas plecoglossicida strain PB1 and Pseudomonas sp. PB2). Both isolates showed promising metabolic capacity on pyrene sprayed MS agar plates during the preliminary investigations. Using time course studies in the liquid cultures at calculated concentrations 123, 64, 97 and 94 ppm for naphthalene, chrysene, fluroanthene and pyrene, P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 showed partial utilization of the polynuclear aromatic hydrocarbons. Naphthalene was degraded between 26% and 40%, chrysene 14% and 16%, fluroanthene 5% and 7%; pyrene 8% and 13% by P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 respectively. Based on their growth profile, we developed a model R2 = 1 to predict the degradation rate of slow polynuclear aromatic hydrocarbon-degraders where all the necessary parameters are constant. From this investigation, we confirm that the former industrial site soil microbial communities may be explored for the biorestoration of the industrial site.
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Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pseudomonas/metabolismo , Filogenia , Pseudomonas/classificação , Pseudomonas/genética , Pirenos/metabolismo , Solo/química , Microbiologia do Solo , Biodegradação Ambiental , Carbono/química , RNA Ribossômico 16S/genética , Crisenos/metabolismo , Naftalenos/metabolismo , Nitrogênio/químicaRESUMO
Estuarine sediments are significant repositories of anthropogenic contaminants, and thus knowledge of the impacts of pollution upon microbial communities in these environments is important to understand potential effects on estuaries as a whole. The Lagos lagoon (Nigeria) is one of Africa's largest estuarine ecosystems, and is impacted by hydrocarbon pollutants and other industrial and municipal wastes. The goal of this study was to elucidate microbial community structure in Lagos lagoon sediments to identify groups that may be adversely affected by pollution, and those that may serve as degraders of environmental contaminants, especially polycyclic aromatic hydrocarbons (PAHs). Sediment samples were collected from sites that ranged in types and levels of anthropogenic impacts. The sediments were characterized for a range of physicochemical properties, and microbial community structure was determined by Illumina sequencing of the 16S rRNA genes. Microbial diversity (species richness and evenness) in the Apapa and Eledu sediments was reduced compared to that of the Ofin site, and communities of both of the former two were dominated by a single operational taxonomic unit (OTU) assigned to the family Helicobacteraceae (Epsilonproteobacteria). In the Ofin community, Epsilonproteobacteria were minor constituents, while the major groups were Cyanobacteria, Bacteroidetes, and Firmicutes, which were all minor in the Apapa and Eledu sediments. Sediment oxygen demand (SOD), a broad indicator of contamination, was identified by multivariate analyses as strongly correlated with variation in alpha diversity. Environmental variables that explained beta diversity patterns included SOD, as well as levels of naphthalene, acenaphthylene, cobalt, cadmium, total organic matter, or nitrate. Of 582 OTU identified, abundance of 167 was significantly correlated (false discovery rate q≤ 0.05) to environmental variables. The largest group of OTU correlated with PAH levels were PAH/hydrocarbon-degrading genera of the Oceanospirillales order (Gammaproteobacteria), which were most abundant in the hydrocarbon-contaminated Apapa sediment. Similar Oceanospirillales taxa are responsive to marine oil spills and thus may present a unifying theme in marine microbiology as bacteria adapted for degradation of high hydrocarbon loads, and may represent a potential means for intrinsic remediation in the case of the Lagos lagoon sediments.
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The goal of this investigation was to isolate competent polynuclear aromatic hydrocarbons degraders that can utilize polynuclear aromatic hydrocarbons of former industrial sites at McDoel Switchyard in Bloomington, Indiana. Using conventional enrichment method based on soil slurry, we isolated, screened and purified two bacterial species strains PB1 and PB2. Applying the ribotyping technique using the 16S rRNA gene analysis, the strains were assigned to the genus Pseudomonas (Pseudomonas plecoglossicida strain PB1 and Pseudomonas sp. PB2). Both isolates showed promising metabolic capacity on pyrene sprayed MS agar plates during the preliminary investigations. Using time course studies in the liquid cultures at calculated concentrations 123, 64, 97 and 94ppm for naphthalene, chrysene, fluroanthene and pyrene, P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 showed partial utilization of the polynuclear aromatic hydrocarbons. Naphthalene was degraded between 26% and 40%, chrysene 14% and 16%, fluroanthene 5% and 7%; pyrene 8% and 13% by P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 respectively. Based on their growth profile, we developed a model R(2)=1 to predict the degradation rate of slow polynuclear aromatic hydrocarbon-degraders where all the necessary parameters are constant. From this investigation, we confirm that the former industrial site soil microbial communities may be explored for the biorestoration of the industrial site.
Assuntos
Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pseudomonas/metabolismo , Biodegradação Ambiental , Carbono/química , Crisenos/metabolismo , Hidrogênio/química , Naftalenos/metabolismo , Nitrogênio/química , Filogenia , Pseudomonas/classificação , Pseudomonas/genética , Pirenos/metabolismo , RNA Ribossômico 16S/genética , Solo/química , Microbiologia do SoloRESUMO
In a previous study, three bacterial strains isolated from tropical hydrocarbon-contaminated soils and phylogenetically identified as Achromobacter sp. strain SL1, Pseudomonas sp. 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-1 h-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.
Assuntos
Achromobacter/metabolismo , Actinobacteria/metabolismo , Carbazóis/metabolismo , Pseudomonas/metabolismo , Poluentes do Solo/metabolismo , Achromobacter/genética , Achromobacter/isolamento & purificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Biodegradação Ambiental , Carbazóis/química , Filogenia , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Microbiologia do SoloRESUMO
In a previous study, three bacterial strains isolated from tropical hydrocarbon-contaminated soils and phylogenetically identified as Achromobacter sp. strain SL1, Pseudomonas sp. 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−1 h−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.
Assuntos
Achromobacter/química , Achromobacter/genética , Achromobacter/isolamento & purificação , Achromobacter/metabolismo , Actinobacteria/química , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Biodegradação Ambiental/química , Biodegradação Ambiental/genética , Biodegradação Ambiental/isolamento & purificação , Biodegradação Ambiental/metabolismo , Carbazóis/química , Carbazóis/genética , Carbazóis/isolamento & purificação , Carbazóis/metabolismo , Filogenia/química , Filogenia/genética , Filogenia/isolamento & purificação , Filogenia/metabolismo , Pseudomonas/química , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , Microbiologia do Solo/química , Microbiologia do Solo/genética , Microbiologia do Solo/isolamento & purificação , Microbiologia do Solo/metabolismo , Poluentes do Solo/química , Poluentes do Solo/genética , Poluentes do Solo/isolamento & purificação , Poluentes do Solo/metabolismoRESUMO
Samples of soil, water, and sediments from industrial estates in Lagos were collected and analyzed for heavy metals and physicochemical composition. Bacteria that are resistant to elevated concentrations of metals (Cd(2+), Co(2+), Ni(2+), Cr(6+), and Hg(2+)) were isolated from the samples, and they were further screened for antibiotic sensitivity. The minimum tolerance concentrations (MTCs) of the isolates with dual resistance to the metals were determined. The physicochemistry of all the samples indicated were heavily polluted. Twenty-two of the 270 bacterial strains isolated showed dual resistances to antibiotics and heavy metals. The MTCs of isolates to the metals were 14 mM for Cd(2+), 15 mM for Co(2+) and Ni(2+), 17 mM for Cr(6+), and 10 mM for Hg(2+). Five strains (Pseudomonas aeruginosa, Actinomyces turicensis, Acinetobacter junni, Nocardia sp., and Micrococcus sp.) resisted all the 18 antibiotics tested. Whereas Rhodococcus sp. and Micrococcus sp. resisted 15 mM Ni(2+), P. aeruginosa resisted 10 mM Co(2+). To our knowledge, there has not been any report of bacterial strains resisting such high doses of metals coupled with wide range of antibiotics. Therefore, dual expressions of antibiotics and heavy-metal resistance make the isolates, potential seeds for decommissioning of sites polluted with industrial effluents rich in heavy metals, since the bacteria will be able to withstand in situ antibiosis that may prevail in such ecosystems.
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Antibacterianos/análise , Bactérias/efeitos dos fármacos , Poluentes Ambientais/análise , Metais Pesados/análise , Acinetobacter/efeitos dos fármacos , Acinetobacter/isolamento & purificação , Acinetobacter/metabolismo , Actinomyces/efeitos dos fármacos , Actinomyces/isolamento & purificação , Actinomyces/metabolismo , Antibacterianos/metabolismo , Antibacterianos/toxicidade , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biodegradação Ambiental , Farmacorresistência Bacteriana Múltipla , Poluentes Ambientais/metabolismo , Poluentes Ambientais/toxicidade , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Testes de Sensibilidade Microbiana , Micrococcus/efeitos dos fármacos , Micrococcus/isolamento & purificação , Micrococcus/metabolismo , Nigéria , Nocardia/efeitos dos fármacos , Nocardia/isolamento & purificação , Nocardia/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/metabolismoRESUMO
The growth rates and pyrene degradation rates of Pseudomonas sp. LP1 and Pseudomonas aeruginosa LP5 were increased in corn steep liquor (CSL) supplemented. On pyrene alone the highest specific growth rate of LP1 was 0.018 h(-1), while on CSL-supplemented pyrene MSM, the value was 0.026 h(-)1. For LP5 the highest growth rate on CSL-supplemented pyrene-MSM was 0.034 h(-1). Conversely, on pyrene alone the highest rate was 0.024 h(-1). CSL led to marked reduction in residual pyrene. In the case of Pseudomonas sp. LP1 values of residual pyrene were 58.54 and 45.47%, respectively, for the unsupplemented and supplemented broth cultures, showing a difference of 13.09%. For LP5 the corresponding values were 64.01 and 26.96%, respectively, showing a difference of 37.05%. The rate of pyrene utilization by LP1 were 0.08 and 0.11 mg l(-1) h(-1) on unsupplemented and supplemented media, respectively. The corresponding values for LP5 were 0.07 and 0.015 mg l(-1) h(-1), respectively. These results suggest that CSL, a cheap and readily available waste product, could be very useful in the bioremediation of environments contaminated with pyrene.
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Pseudomonas/metabolismo , Pirenos/metabolismo , Zea mays/química , Meios de Cultura/metabolismo , Pseudomonas/crescimento & desenvolvimento , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/metabolismoRESUMO
The ability of microorganisms to degrade petroleum hydrocarbons is important for finding an environmentally-friendly method to restoring contaminated environmental matrices. Screening of hydrocarbon-utilizing and biosurfactant-producing abilities of organisms from an estuarine ecosystem in Nigeria, Africa, resulted in the isolation of five microbial strains identified as Corynebacterium sp. DDv1, Flavobacterium sp. DDv2, Micrococcus roseus DDv3, Pseudomonas aeruginosa DDv4 and Saccharomyces cerevisae DDv5. These isolates grew readily on several hydrocarbons including hexadecane, dodecane, crude oil and petroleum fractions. Axenic cultures of the organisms utilized diesel oil (1.0 % v/v) with generation times that ranged significantly (t-test, P < 0.05) between 3.25 and 3.88 day, with concomitant production of biosurfactants. Kinetics of growth indicates that biosurfactant synthesis occurred predominantly during exponential growth phase, suggesting that the bioactive molecules are primary metabolites. Strains DDv1 and DDv4 were evidently the most metabolically active in terms of substrate utilization and biosurfactant synthesis compared to other strains with respective emulsification index of 63 and 78 %. Preliminary biochemical characterization indicates that the biosurfactants are heteropolymers consisting of lipid, protein and carbohydrate moieties. The hydrocarbon catabolic properties coupled with biosurfactant-producing capabilities is an asset that could be exploited for cleanup of oil-contaminated matrices and also in food and cosmetic industries. Rev. Biol. Trop. 56 (4): 16031611. Epub 2008 December 30.
La capacidad de los microorganismos para degradar hidrocarburos del petróleo es de gran importancia para hallar un método aceptable y ambientalmente amigable para la restauración de terrenos ambientalmente contaminados. Al investigar las capacidades de los organismos de un ecosistema de estuario que utilizan hidrocarburos y producen biosurfactantes, se produjo como resultado el aislamiento de cinco cepas microbianas identificadas como Corynebacterium sp. DDv1, Flavobacterium sp. DDv2, Micrococcus roseus DDv3, Pseudomonas aeruginosa y DDv4 Saccharomyces cerevisiae DDv5. Estas cepas crecieron fácilmente en varios hidrocarburos incluyendo hexadecanos, dodecanos, petróleo crudo y fracciones de petróleo. Los cultivos axénicos de organismos utilizaron diesel (1.0% v/v) con períodos por generación con ámbitos significativos (t-test, P <0.05) de entre 3.25 y 3.88 días, con la consiguiente producción de bio-surfactantes. La cinética del crecimiento indica que la síntesis de bio-surfactante se produjo principalmente durante la fase de crecimiento exponencial, lo que sugiere que las moléculas bioactivas son metabolitos primarios. Las cepas DDv1 y DDv4 fueron evidentemente las más metabólicamente activas en términos de utilización del sustrato y la síntesis de bio-surfactantes en comparación con otras cepas con índices respectivos de emulsificación de 63 y 78%. La caracterización bioquímica preliminar indica que los bio-surfactantes son heteropolímeros constituidos de fracciones de lípidos, proteínas y carbohidratos. Las propiedades catabólicas de los hidrocarburos, junto con las capacidades de producción de bio-surfactantes, es una ventaja que puede ser aprovechada para la limpieza de terrenos contaminados con petróleo y también en la industria alimentaria y cosmética.
Assuntos
Bactérias Gram-Negativas/metabolismo , Bactérias Gram-Positivas/metabolismo , Petróleo/metabolismo , Saccharomyces/metabolismo , Tensoativos/metabolismo , Alcanos/metabolismo , Biodegradação Ambiental , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Nigéria , Saccharomyces/crescimento & desenvolvimento , Fatores de TempoRESUMO
Evidence for substantial aerobic degradation of Aroclor 1242 and Askarel fluid by newly characterized bacterial strains belonging to the Enterobacter, Ralstonia and Pseudomonas genera is presented. The organisms exhibited degradative activity in terms of total PCB/Askarel degradation, degradation of individual congeners and diversity of congeners attacked. Maximal degradation by the various isolates of Askarel ranged from 69% to 86% whereas, Aroclor 1242, with the exception of Ralstonia sp. SA-4 (9.7%), was degraded by 37% to 91%. PCB analysis showed that at least 45 of the representative congeners in Aroclor 1242 were extensively transformed by benzoate-grown cells without the need for biphenyl as an inducer of the upper degradation pathway. In incubations with Aroclor 1242, no clear correlation was observed between percentage of congener transformed and the degree of chlorination, regardless of the presence or absence of biphenyl. Recovery of significant but nonstoichiometric amounts of chloride from the culture media showed partial dechlorination of congeners and suggested production of partial degradation products. Addition of biphenyl evidently enhanced dechlorination of the mixture by some isolates. With the exception of Ralstonia sp. SA-5, chloride released ranged from 24% to 60% in the presence of biphenyl versus 0.35% to 15% without biphenyl.