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Seleção de bactérias para biodegradação dos pesticidas organoclorados DDD, PCP e dieldrin; Selection of bacteria for biodegradation of organochlorine pesticides DDD, PCP and dieldrin

Kasemodel, Mariana Consiglio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/10/2012 PT
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O objetivo deste trabalho foi a seleção de bactérias capazes de biodegradar os pesticidas organoclorados dieldrin, DDD e PCP. Inicialmente, foram realizados os ensaios de tolerância visando à seleção das bactérias degradadoras; posteriormente foram realizados os ensaios de biodegradação em meio liquido utilizando a bactéria selecionada. Dentre as 14 linhagens bacterianas isoladas testadas, selecionou-se a linhagem Pseudomonas aeruginosa L2-1 por apresentar maior tolerância a todos os pesticidas. Os ensaios de biodegradação foram realizados em diferentes meios de cultura, variando-se a concentração de glicose, a fonte de nitrogênio e a presença de ramnolipídeo. Os ensaios de biodegradação foram realizados determinando-se a concentração de pesticida, a concentração de glicose, o número de células viáveis, e o pH. O meio de cultura que mais favoreceu a biodegradação dos três pesticidas foi o meio com nitrato de sódio e 0,5% de glicose, obtendo-se biodegradação de aproximadamente 50% para cada pesticida após três dias de incubação. Na ausência de glicose, o meio com nitrato de amônio e 0,1% de ramnolipídeo, favoreceu a biodegradação, obtendo-se após 14 dias de incubação 36,8% de biodegradação de dieldrin; 33...

Biodegradação dos pesticidas clorpirifós, metil paration e profenofós por fungos de origem marinha; Biodegradation of pesticides chlorpyrifos, methyl parathion and profenofos by marine fungi

Silva, Natália Alvarenga da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/04/2013 PT
Relevância na Pesquisa
37.1%
Neste trabalho, foi realizada uma triagem com os fungos marinhos Aspergillus sydowii CBMAI 934, Aspergillus sydowii CBMAI 935, Aspergillus sydowii 1241, Penicillium decaturense CBMAI 1234, Penicillium raistrickii CBMAI 931, Penicillium raistrickii CBMAI 1235 e Trichoderma sp. CBMAI 932 com o objetivo de avaliar o potencial enzimático destes micro-organismos frente à biodegradação dos pesticidas organofosforados clorpirifós, metil paration e profenofós. Os fungos selecionados para as reações em meio líquido de malte 2%, que melhor adaptaram-se na presença do pesticida clorpirifós, foram as cepas de A. sydowii CBMAI 935 e Trichoderma sp. CBMAI 932, na presença de metil paration foram A. sydowii CBMAI 935 e P. decaturense CBMAI 1234 e na presença de profenofós foram os fungos A. sydowii CBMAI 935 e P. raistrickii CBMAI 931. Foram realizadas curvas analíticas com o objetivo de estimar a extensão da biodegradação dos pesticidas clorpirifós, metil paration, profenofós, e seus respectivos produtos de hidrólise, os derivados fenólicos 3,5,6-tricloro-2-piridinol, 4-nitrofenol e 4-bromo-2-clorofenol, respectivamente. As reações de biodegradação em meio líquido de malte 2% foram avaliadas com 10, 20 e 30 dias de reação com concentração inicial dos pesticidas organofosforados de 50 ppm. O pesticida...

Biodegradação do pesticida esfenvalerato por fungos de ambiente marinho; Biodegradation of the pesticide esfenvalerate by marine-derived fungi

Birolli, Willian Garcia
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 21/02/2014 PT
Relevância na Pesquisa
37.14%
Desde a revolução verde, na década de 1950, o processo tradicional de produção agrícola passou por mudanças com a inserção do uso intensivo de agrotóxicos como os piretróides, que são a terceira classe química de pesticidas mais comercializada no mundo. Estes compostos geralmente são ésteres que contêm um anel dimetilciclopropano com grupamentos variáveis e a presença de anéis aromáticos. Cada vez mais os cientistas vêm explorando a diversidade microbiana na biodegradação de pesticidas e neste contexto, o emprego de fungos de ambiente marinho possui grande potencialidade devido ao seu sistema enzimático único com a presença de compostos altamente oxigenados e halogenados, assim como o esfenvalerato empregado neste trabalho. Entretanto, estes micro-organismos não têm sido explorados na biotransformação de pesticidas piretróides. Neste estudo foi avaliada a eficiência de fungos de ambiente marinho [Penicillium raistrickii CBMAI 931, Aspergillus sydowii CBMAI 935, Cladosporium sp. CBMAI 1237, Microsphaeropsis sp. Dr(A)6, Acremonium sp. Dr(F)1, Westerdykella sp. Dr(M2)4 e Cladosporium sp. Dr(M2)2] na degradação do pesticida piretróide esfenvarelato. Observou-se que o esfenvalerato e seus principais metabólitos de degradação causam efeitos inibitórios significativos no crescimento dos fungos...

Biodegradação de madeira por Ceriporiopsis subvermispora: caracterização dos polímeros residuais; Biodegradation of the wood Ceriporiopsis subvermispora: characterization of residual polymers

Guerra, Anderson de Almeida
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/05/2002 PT
Relevância na Pesquisa
37.14%
A Biopolpação é definida como o pré-tratamento de cavacos de madeira, designado como um processo de fermentação em estado sólido, para a produção de polpas mecânicas e químicas. Apesar dos resultados promissores obtidos pelo pré-tratamento com fungos seguido de reações de polpação, não há correlação entre o padrão de biodegradação dos componentes da madeira e o aumento na eficiência dos métodos de polpação subseqüentemente utilizados. Esta falta de correlação sugere que os benefícios do biotratamento dependem mais do tipo de modificação induzida na madeira do que da extensão da mineralização de seus componentes. Dentro deste contexto, este estudo visa o entendimento dos mecanismos químicos e bioquímicos, que poderiam explicar as alterações estruturais ocorridas nos componentes principais da madeira durante a etapa de biopolpação. Pinus taeda foi degradado por Ceriporiopsis subvermispora por períodos de 15 a 90 dias em condições de fermentação sólida. O fungo degradou lignina e extrativos extensivamente, sem remover grandes quantidades de glucana. As polioses foram significativamente removidas após 60 dias de degradação (7%), chegando a 31 % após 90 dias. A lignina e os polissacarídeos residuais ...

Aerobic biodegradation of butanol and gasoline blends

Mariano, Adriano Pinto; Tomasella, Richard Clayton; Di Martino, Clara; Maciel Filho, Rubens; Regali Seleghim, Mirna Helena; Contiero, Jonas; de Angelis, Dejanira de Franceschi
Fonte: Pergamon-Elsevier B.V. Ltd Publicador: Pergamon-Elsevier B.V. Ltd
Tipo: Artigo de Revista Científica Formato: 1175-1181
ENG
Relevância na Pesquisa
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This work aimed to assess the aerobic biodegradation of butanol/gasoline, blends (5; 10; 15 and 20% v/v), being the latter compared to the ethanol/gasoline blend (20% v/v). Two experimental techniques were employed, namely the respirometric method and the redox indicator DCPIP test. in the former, experiments simulating the contamination of natural environments (addition of 50 mL of fuel kg(-1) of soil from a non-contaminated site and 20 mL of fuel L(-1) of water from a river) were carried out in biometer flasks (250 mL), used to measure the microbial CO(2) production. The DCPIP test assessed the capability of four inocula to biodegrade the blends of 20%. The addition of butanol at different concentrations enhanced the biodegradation of gasoline in soil. However, no practical gains were observed for concentrations of butanol above 10%. Ethanol showed to have a much faster biodegradation rate than butanol, particularly in water, and the following order of biodegradability was found: ethanol > butanol > gasoline. The addition of the alcohols to the gasoline resulted in positive synergic effects on the biodegradation of the fuels in soil and water matrices. Furthermore, results suggest that, in soil, butanol better enhanced the biodegradation of gasoline than ethanol. (C) 2009 Elsevier Ltd. All rights reserved

Applied models to biodegradation kinetics of lubricant and vegetable oils in wastewater

Montagnolli, Renato N.; Lopes, Paulo R. M.; Bidoia, Ederio Dino
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 297-305
ENG
Relevância na Pesquisa
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Bioremediation technologies are used in order to remove pollutants from the environment in a safe, economical and harmless way during the treatment of waste, especially with the use of techniques such as biodegradation. A lubricant and vegetable oil contaminated water sample was studied in order to evaluate the biodegradability of different types of oils, considering the relevance of the obtained data in the bioremediation procedures. The objective of this paper is to use respirometry technique as a biodegradation process data source, and then apply to the obtained data the experimental design of mathematical models to characterize and determinate how the different types of oils are capable of affecting the parameters in biodegradation kinetics. The kinetics was then evaluated through selected models with a reasonable fit to experimental data. The Bartha and Pramer respirometer is used as a method to accurately measure the CO(2) formation in the organic compounds degradation by microorganisms. Therefore, the difference in biodegradation efficiency process is compared in the different groups of oils using mathematical models fitting the obtained data for the kinetics of biodegradation. The results demonstrated that used lubricant automotive oils are more susceptible to the biodegradation process...

Cellular damages in the Allium cepa test system, caused by BTEX mixture prior and after biodegradation process

Mazzeo, Dânia Elisa Christofoletti; Fernandes, Thaís Cristina Casimiro; Marin-Morales, Maria Aparecida
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 13-18
ENG
Relevância na Pesquisa
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Petroleum and derivatives have been considered one of the main environmental contaminants. Among petroleum derivatives, the volatile organic compounds benzene, toluene, ethylbenzene and xylene (BTEX) represent a major concern due to their toxicity and easy accumulation in groundwater. Biodegradation methods seem to be suitable tools for the clean-up of BTEX contaminants from groundwater. Genotoxic and mutagenic potential of BTEX prior and after biodegradation process was evaluated through analyses of chromosomal aberrations and MN test in meristematic and F 1 root cells using the Allium cepa test system. Seeds of A. cepa were germinated into five concentrations of BTEX, non-biodegraded and biodegraded, in ultra-pure water (negative control), in MMS 4×10 -4M (positive control) and in culture medium used in the biodegradation (blank biodegradation control). Results showed a significant frequency of both chromosomal and nuclear aberrations. The micronucleus (MN) frequency in meristematic cells was significant for most of tested samples. However, MN was not present in significant levels in the F 1 cells, suggesting that there was no permanent damage for the meristematic cell. The BTEX effects were significantly reduced in the biodegraded samples when compared to the respective non-biodegraded concentrations. Therefore...

Acid dye biodegradation using saccharomyces cerevisiae immobilized with polyethyleneimine-treated sugarcane bagasse

Mitter, E. K.; Corso, C. R.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Chemical reagents used by the textile industry are very diverse in their composition, ranging from inorganic compounds to polymeric compounds. Strong color is the most notable characteristic of textile effluents, and a large number of processes have been employed for color removal. In recent years, attention has been directed toward various natural solid materials that are able to remove pollutants from contaminated water at low cost, such as sugarcane bagasse. Cell immobilization has emerged as an alternative that offers many advantages in the biodegradation process, including the reuse of immobilized cells and high mechanical strength, which enables metabolic processes to occur under adverse conditions of pH, sterility, and agitation. Support treatment also increases the number of charges on the surface, thereby facilitating cell immobilization processes through adsorption and ionic bonds. Polyethyleneimine (PEI) is a polycationic compound known to have a positive effect on enzyme activity and stability. The aim of the present study was to investigate a low-cost alternative for the biodegradation and bioremediation of textile dyes, analyzing Saccharomyces cerevisiae immobilization in activated bagasse for the promotion of Acid Black 48 dye biodegradation in an aqueous solution. A 1 % concentration of a S. cerevisiae suspension was evaluated to determine cell immobilization rates. Once immobilization was established...

Application of micronucleus test and comet assay to evaluate BTEX biodegradation

Mazzeo, Dânia Elisa Christofoletti; Matsumoto, Silvia Tamie; Levy, Carlos Emílio; de Angelis, Dejanira de Franceschi; Marin-Morales, Maria Aparecida
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1030-1036
ENG
Relevância na Pesquisa
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The BTEX (benzene, toluene, ethylbenzene and xylene) mixture is an environmental pollutant that has a high potential to contaminate water resources, especially groundwater. The bioremediation process by microorganisms has often been used as a tool for removing BTEX from contaminated sites. The application of biological assays is useful in evaluating the efficiency of bioremediation processes, besides identifying the toxicity of the original contaminants. It also allows identifying the effects of possible metabolites formed during the biodegradation process on test organisms. In this study, we evaluated the genotoxic and mutagenic potential of five different BTEX concentrations in rat hepatoma tissue culture (HTC) cells, using comet and micronucleus assays, before and after biodegradation. A mutagenic effect was observed for the highest concentration tested and for its respective non-biodegraded concentration. Genotoxicity was significant for all non-biodegraded concentrations and not significant for the biodegraded ones. According to our results, we can state that BTEX is mutagenic at concentrations close to its water solubility, and genotoxic even at lower concentrations, differing from some described results reported for the mixture components...

FT-IR analysis of acid black dye biodegradation using saccharomyces cerevisiae immobilized with treated sugarcane bagasse

Mitter, E. K.; Corso, C. R.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.14%
Textile industries use large amounts of water in dyeing processes and a wide variety of synthetic dyes. A small concentration of these dyes in the environment can generate highly visible pollution and changes in aquatic ecosystems. Adsorption, biosorption, and biodegradation are the most advantageous dye removal processes. Biodegradation occurs when enzymes produced by certain microorganisms are capable of breaking down the dye molecule. To increase the efficiency of these processes, cell immobilization enables the reuse of the immobilized cells and offers a high degree of mechanical strength, allowing metabolic processes to take place under adverse conditions. The aim of the present study was to investigate the use of Saccharomyces cerevisiae immobilized in activated sugarcane bagasse for the degradation of Acid Black 48 dye in aqueous solutions. For such, sugarcane bagasse was treated with polyethyleneimine (PEI). Concentrations of a 1 % S. cerevisiae suspension were evaluated to determine cell immobilization rates. Once immobilization was established, biodegradation assays for 240 h with free and immobilized yeast in PEI-treated sugarcane bagasse were evaluated by Fourier transform infrared spectrophotometry. The results indicated a probable change in the dye molecule and the possible formation of new metabolites. Thus...

Estudo da microbiota e da biodegradação de petroleo de bacias brasileiras, e sua implicação nos parametros de biodegradação; Study of the microbiota and of petroleum biodegradation in Brazilian basins, and its consequences on the biodegradation parameters

Celio Fernando Figueiredo Angolini
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 19/02/2010 PT
Relevância na Pesquisa
37.2%
O principal objetivo desse trabalho foi avaliar a biodegradação de petróleo e suas implicações nos parâmetros de correlação do óleo realizada por microrganismos isolados da Bacia de Campos (RJ) e de consórcios microbianos da Bacia Potiguar (RN). Os experimentos de biodegradação foram adaptados à escala laboratorial, a fim de mimetizar um reservatório de petróleo. O estudo das atividades enzimáticas com moléculas representantes de algumas classes de biomarcadores de petróleo revelou a existência de enzimas capazes de realizar algumas reações como as de: lipase, esterase, epóxido-hidrolase, mono e dioxidases, redutases e liases (reações de formação e/ou rompimento de ligações carbono-carbono). Atividades essas importantes na degradação do petróleo e de outras fontes de carbono. Nos experimentos com biodegradação de petróleo pôde-se perceber que os microrganismos isolados atuaram de forma diferente entre si sobre as diferentes classes de biomarcadores. De maneira geral a biodegradação dos microrganismos isolados com o óleo P1 apresentou uma preferência na seguinte ordem: hidrocarbonetos saturados > aromáticos leves > bicíclicos > terpanos tricíclicos e hopanos. Já para o consorcio avaliado, recuperado do óleo da bacia Potiguar...

Avaliação da diversidade filogenética e funcional da microbiota envolvida na biodegradação de hidrocarbonetos em amostras de petróleo de reservatórios brasileiros = : Evaluation of the phylogenetic and functional diversity of the microbiota involved in hydrocarbon biodegradation in petroleum samples from Brazilian reservoirs; Evaluation of the phylogenetic and functional diversity of the microbiota involved in hydrocarbon biodegradation in petroleum samples from Brazilian reservoirs

Leandro Costa Lima Verde
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/05/2014 PT
Relevância na Pesquisa
37.1%
O processo de biodegradação do petróleo em reservatórios pode resultar em mudanças na composição e propriedades físico-químicas de óleos brutos e gases naturais, as quais levam à diminuição do teor de hidrocarbonetos saturados, produzindo óleos mais pesados e com baixo valor econômico. O uso combinado de técnicas dependentes e independentes de cultivo pode nos permitir um melhor entendimento acerca da comunidade de micro-organismos que habita os reservatórios de petróleo, incluindo aqueles responsáveis por esta biodegradação. O conhecimento sobre a composição microbiana, suas funções e interações com outros micro-organismos e com o ambiente pode levar à definição de estratégias de monitoramento e/ou controle da biodegradação em reservatórios. Este estudo teve como finalidade avaliar a diversidade de micro-organismos e genes envolvidos na degradação de hidrocarbonetos presentes em amostras de petróleo provenientes de dois poços terrestres da Bacia Potiguar (RN), identificados como GMR75 (poço biodegradado) e PTS1 (poço não-biodegradado), através da construção de bibliotecas de genes catabólicos (alcano monooxigenases - alk, dioxigenases que hidroxilam anéis aromáticos - ARHDs e 6-oxocyclohex-1-ene-1-carbonyl-CoA hidroxilase - bamA) e sequenciamento em larga escala de metagenoma e metatranscriptoma de enriquecimentos microbianos aeróbios. Os resultados obervados mostraram uma distribuição diferencial dos genes catabólicos entre os reservatórios...

Effect of low concentrations of synthetic surfactants on polycyclic aromatic hydrocarbons (PAH) biodegradation

Rodrigues, A. C.; Nogueira, R.; Melo, L. F.; Brito, A. G.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
Relevância na Pesquisa
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The present study is focused on the effect of synthetic surfactants, at low concentration, on the kinetics of polycyclic aromatic hydrocarbons (PAH) biodegradation by Pseudomonas putida ATCC 17514 and addresses the specific issue of the effect of the surfactant on bacterial adhesion to PAH, which is believed to be an important mechanism for the uptake of hydrophobic compounds. For that purpose, three surfactants were tested, namely, the nonionic Tween 20, the anionic sodium dodecyl sulphate (SDS) and the cationic surfactant cetyltrymethyl ammonium bromide (CTAB). Data showed that the effect of each surfactant on the ability of strain ATCC 17514 to biodegrade fluoranthene and anthracene and to use them as growth substrate varied considerably. Tween 20, at a concentration of 0.08 mM, increased the biodegradation rate of fluoranthene and doubled the maximum specific biodegradation rate of anthracene. The presence of SDS, at a concentration of 0.35 mM, led to a reduction of 50% on the biodegradation rate of fluoranthene, but doubled the removal rate of the more hydrophobic anthracene (0.3 mg L−1 h−1). Finally, CTAB, at a concentration of 0.27 mM, had a negative effect on the biodegradation of both PAH, leading to an abrupt decrease on the biomass growth.

Biodegradation of Beta-Blockers and Fluoxetine followed by a Chiral HPLC-FD

Ribeiro, Ana R.; Castro, Paula M. L.; Afonso, Carlos; Tiritan, Maria E.
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Conferência ou Objeto de Conferência
Publicado em //2011 ENG
Relevância na Pesquisa
37.1%
Despite of the massive publications concerning pharmaceuticals in the environment, the problematic related with chiral compounds and enantioselective degradation are still largely unknown [1]. Enantiomers have different interactions with enzymes, receptors and other chiral molecules, leading to different biological activities. Thus, biodegradation tends to be enantioselective in contrast to abiotic degradation. However, biodegradation studies regarding enantioselectivity on the process are scarce [2].] MATERIALS AND METHODS [Four beta-blockers: alprenolol (ALP), propranolol (PHO), metoprolol (MET) and atenolol (ATE) and the antidepressant fluoxetine (FX) were enantiomerically separated by a macrocyclic antibiotic vancomycin CSP (ASTEC Chirobiotic V 5µm) under polar organic mode phase (methanol:ethanol:triethylamine:acetic acid.50:50 v/v) and fluorescence detection for enantiomeric fraction quantification. The developed methods were established using a minimal medium inoculated with activated sludge (AS) as a matrix.] RESULTS AND DISCUSSION [The Chirobiotic VTM was able to resolve ALP and PHO as well as MET, ATE and FX in two short runs. A separation factor (α) between 1.12 and 1.34 and resolution (Rs) between 1.30 and 4.35 were obtained. The methods demonstrated to be selective and linear within the range...

Chiral HPLC-FD method validation for determination of several Beta-Blockers and Fluoxetine in biodegradation assays

Ribeiro, Ana R.; Castro, Paula M.L.; Afonso, Carlos; Tiritan, Maria E.
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Conferência ou Objeto de Conferência
Publicado em //2011 ENG
Relevância na Pesquisa
37.1%
Chiral pharmaceuticals and the fate and effects of their enantiomers in the environment are still largely unknown [1, 2]. Enantiomers have different interactions with enzymes, receptors and any chiral molecules leading to different biological activities and affecting organisms in a different manner. Thus, biodegradation tends to be enantioselective in contrast to abiotic degradation. The methods developed to quantify the enantiomeric fraction in the environment and to follow biodegradation are scarce [3]. Thus in this work we describe the development and validation of HPLC methods that allow the enantiomeric separation of widely used drugs namely four beta-blockers: alprenolol (ALP), propranolol (PHO), metoprolol (MET) and atenolol (ATE) and the antidepressant fluoxetine (FX). The macrocyclic antibiotic vancomycin CSP (ASTEC Chirobiotic V 5µm) was used under polar organic mode (methanol:ethanol:triethylamine:acetic acid.50:50 v/v) and fluorescence detection for enantiomeric fraction quantification. The developed methods were established using a minimal medium inoculated with activated sludge as a matrix which is the condition used in the biodegradation studies. The vancomycin CSP was able to resolve ALP and PHO as well as MET, ATE and FX in two chromatographic runs. The chromatographic parameters obtained have shown the separation factor (α) between 1.12 and 1.34 and resolution (Rs) between 1.30 and 4.35. The methods demonstrated to be selective and linearity with r2 higher than 0...

A biodegradation study of forest biomass by Aspergillus niger F7: correlation between enzymatic activity, hydrolytic percentage and biodegradation index

Sharma,Nivedita; Kaushal,Richa; Gupta,Rakesh; Kumar,Sanjeev
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
Relevância na Pesquisa
37.1%
Aspergillus niger F7 isolated from soil was found to be the potent producer of cellulase and xylanase. The residue of forest species Toona ciliata, Celtris australis, Cedrus deodara and Pinus roxburghii was selected as substrate for biodegradation study due to its easy availability and wide use in industry. It was subjected to alkali (sodium hydroxide) treatment for enhancing its degradation. Biodegradation of forest waste by hydrolytic enzymes (cellulase and xylanase) secreted by A. niger under solid state fermentation (SSF) was explored. SSF of pretreated forest biomass was found to be superior over untreated forest biomass. Highest extracellular enzyme activity of 2201±23.91 U/g by A. niger was shown in pretreated C. australis wood resulting in 6.72±0.20 percent hydrolysis and 6.99±0.23 biodegradation index (BI). The lowest BI of 1.40±0.08 was observed in untreated saw dust of C. deodara having the least enzyme activity of 238±1.36 U/g of dry matter. Biodegradation of forest biomass under SSF was increased many folds when moistening agent i.e. tap water had been replaced with modified basal salt media (BSM). In BSM mediated degradation of forest waste with A. niger, extracellular enzyme activity was increased up to 4089±67.11 U/g of dry matter in turn resulting in higher BI of 15.4±0.41 and percent hydrolysis of 19.38±0.81 in pretreated C. australis wood. A. niger exhibited higher enzyme activity on pretreated biomass when moistened with modified BSM in this study. Statistically a positive correlation has been drawn between these three factors i.e. enzyme activity...

Carbon and Hydrogen Isotopic Fractionation during Anaerobic Biodegradation of Benzene

Mancini, Silvia A.; Ulrich, Ania C.; Lacrampe-Couloume, Georges; Sleep, Brent; Edwards, Elizabeth A.; Sherwood Lollar, Barbara
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /01/2003 EN
Relevância na Pesquisa
37.25%
Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in the subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting processes are reported for the first time. Different enrichment factors (ɛ) for carbon (range of −1.9 to −3.6‰) and hydrogen (range of −29 to −79‰) fractionation were observed during biodegradation of benzene under nitrate-reducing, sulfate-reducing, and methanogenic conditions. These differences are not related to differences in initial biomass or in rates of biodegradation. Carbon isotopic enrichment factors for anaerobic benzene biodegradation in this study are comparable to those previously published for aerobic benzene biodegradation. In contrast, hydrogen enrichment factors determined for anaerobic benzene biodegradation are significantly larger than those previously published for benzene biodegradation under aerobic conditions. A fundamental difference in the previously proposed initial step of aerobic versus proposed anaerobic biodegradation pathways may account for these differences in hydrogen isotopic fractionation. Potentially...

Identification of Biomarker Genes To Predict Biodegradation of 1,4-Dioxane

Gedalanga, Phillip B.; Pornwongthong, Peerapong; Mora, Rebecca; Chiang, Sheau-Yun Dora; Baldwin, Brett; Ogles, Dora; Mahendra, Shaily
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /05/2014 EN
Relevância na Pesquisa
37.14%
Bacterial multicomponent monooxygenase gene targets in Pseudonocardia dioxanivorans CB1190 were evaluated for their use as biomarkers to identify the potential for 1,4-dioxane biodegradation in pure cultures and environmental samples. Our studies using laboratory pure cultures and industrial activated sludge samples suggest that the presence of genes associated with dioxane monooxygenase, propane monooxygenase, alcohol dehydrogenase, and aldehyde dehydrogenase are promising indicators of 1,4-dioxane biotransformation; however, gene abundance was insufficient to predict actual biodegradation. A time course gene expression analysis of dioxane and propane monooxygenases in Pseudonocardia dioxanivorans CB1190 and mixed communities in wastewater samples revealed important associations with the rates of 1,4-dioxane removal. In addition, transcripts of alcohol dehydrogenase and aldehyde dehydrogenase genes were upregulated during biodegradation, although only the aldehyde dehydrogenase was significantly correlated with 1,4-dioxane concentrations. Expression of the propane monooxygenase demonstrated a time-dependent relationship with 1,4-dioxane biodegradation in P. dioxanivorans CB1190, with increased expression occurring after over 50% of the 1...

Elucidating the factors influencing the biodegradation of cylindrospermopsin in drinking water sources

Smith, M.; Shaw, G.; Eaglesham, G.; Ho, L.; Brookes, J.
Fonte: John Wiley & Sons Inc Publicador: John Wiley & Sons Inc
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
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37.17%
The cyanotoxin cylindrospermopsin (CYN) is produced by several species of cyanobacteria and can be persistent in drinking waters supplies, which is of major concern to water authorities because of its potential to severely compromise human health. Consequently, there is a need to fully understand the persistence of CYN in water supplies, in particular, to determine whether this toxin is readily degraded by endemic aquatic organisms. This study provides insights into the environmental factors that can influence the biodegradation of this toxin in Australian drinking water supplies. Biodegradation of CYN was only evident in water supplies that had a history of toxic Cylindrospermopsis raciborskii blooms. In addition, lag periods were evident prior to the onset of biodegradation; however, repeated exposure of the endemic organisms to CYN resulted in substantial decreases in the lag periods. Furthermore, the concentration of CYN was shown to influence biodegradation with a near linear relationship (R(2) of 0.9549) existing between the biodegradation rate and the initial CYN concentration. Temperature was also shown to affect the biodegradation of CYN, which is important since CYN is now being detected in more temperate climates. The presence of copper-based algicides inhibited CYN degradation...

Biodegradation of a Sulfur-Containing PAH, Dibenzothiophene, by a Mixed Bacterial Community

Cooper, Ellen M.
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 5161465 bytes; application/pdf
Publicado em //2009 EN_US
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37.17%

Dibenzothiophene (DBT) is a constituent of creosote and petroleum waste contamination, it is a model compound for more complex thiophenes, and its degradation by mixed microbial communities has received little attention. The chemical characteristics, environmental fate and ecotoxicology of DBT degradation products are not well understood. This research investigated DBT degradation in an enrichment culture derived from creosote-contaminated estuarian sediment using a suite of assays to monitor bacterial populations, bacterial growth, degradation products, DBT loss, and toxicity. Ultraviolet (UV) irradiation was evaluated as a sequential treatment following biodegradation. Additionally, to advance SYBR-Green qPCR methodology for characterizing mixed microbial communities, an alternative approach for evaluating qPCR data using a sigmoidal model to fit the amplification curve was compared to the conventional approach in artificial mixed communities. The overall objective of this research was to gain a comprehensive understanding of the degradation of a model heterocyclic PAH, DBT, by a mixed microbial community, particularly within the context of remediation goals.

DBT biodegradation was evaluated in laboratory scale cultures with and without pH control. The microbial community was monitored with 10 primer sets using SYBR-Green quantitative polymerase chain reaction (qPCR). Twenty-seven degradation products were identified by gas chromatography and mass spectrometry (GC/MS). The diversity of these products indicated that multiple pathways functioned in the community. DBT degradation appeared inhibited under acidic conditions. Toxicity to bioluminescent bacteria Vibrio fischeri more than doubled in the first few days of degradation...