Exopolymeric Substances (EPS) Produced by Petroleum Microbial Consortia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Microbial consortia recuperated of crude oil samples from the Pampo Sul field, Campos Basin, RJ, produced biosurfactants in mineral media containing glucose and 9,10-dihydrophenantrene, n-nonadecane, nonadecanoic acid, slightly biodegraded crude oil (P1) or heavily biodegraded crude oil (P2) as carbon sources. The production of exopolimeric substances (EPS) and petroleum biodegradation do not necessarily occur simultaneously. The EPS analyses by infrared and eletronspray ionization mass spectrometry (ESI-MS) revealed a mixture of surfactine isoforms. The biosurfactants reduced the surface tension of water and Zinder medium from 72.4 and 55.7 to 28.6 mN m(-1). Additionally, this surfactant emulsified different oils in water with performances similar to or better than of a conventional surfactant, Tween 80.21815171523FINEPPETROBRASCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Screening for hydrocarbon biodegraders in a metagenomic clone library derived from Brazilian petroleum reservoirs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Metagenomics has been successfully applied to isolate novel biocatalysts from diverse environments and functional screening has been used as the primary technique to identify clones carrying the desired traits. This work aimed at the construction and screening of a metagenomic library as a source of potential hydrocarbon biodegraders. A library of 31000 clones was obtained from aerobic and anaerobic enrichments generated using a biodegraded petroleum sample collected at the Potiguar Basin in Brazil as an inoculum. A total of 5000 clones were randomly selected for high throughput screening of hexadecane biodegradation, revealing 72 positive hits. These were further evaluated using gas chromatography-mass spectrometry (GC-MS), outstanding hexadecane biodegradation ability (>70%) being detected in five clones. (C) 2010 Elsevier Ltd. All rights reserved.417675681PETROBRASFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Isolation, biodegradation ability and molecular detection of hydrocarbon degrading bacteria in petroleum samples from a Brazilian offshore basin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The detection of microorganisms with potential for biodeterioration and biodegradation in petroleum fields is of great relevance, since these organisms may be related to a decrease in petroleum quality in the reservoirs or damage in the production facilities. In this sense, petroleum formation water and oil samples were collected from the Campos Basin, Brazil, with the aim of isolating microorganisms and evaluating their ability to degrade distinct classes of hydrocarbon biomarkers (9,10-dihydrophenanthrene, phytane, nonadecanoic acid and 5 alpha-cholestane). Twenty eight bacterial isolates were recovered and identified by sequencing their 16S rRNA genes. Biodegradation assays revealed that bacterial metabolism of hydrocarbons occurred through reactions based on oxidation, carbon-carbon bond cleavage and generation of new bonds or by the physical incorporation of hydrocarbons into microbial cell walls. Based on the biodegradation results, selective PCR-based systems were developed for direct detection in petroleum samples of bacterial groups of interest, namely Bacillus spp., Micrococcus spp., Achromobacter xylosoxidans, Dietzia spp. and Bacillus pumilus. Primer sets targeting 16S rRNA genes were designed and their specificity was confirmed in silico (i.e. computational analysis) and in PCR reactions using DNA from reference strains as positive and negative controls. Total DNA from oil was purified and the amplification tests revealed the presence of the target bacteria in the samples, unraveling a significant potential for petroleum deterioration in the reservoirs sampled, once proper conditions are present for hydrocarbon degradation. The application of molecular methods for rapid detection of specific microorganisms in environmental samples would be valuable as a supporting tool for the evaluation of oil quality in production reservoirs. (C) 2009 Elsevier Ltd. All rights reserved.405574588FINEP [01.04.0550.00]PETROBRASCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FINEP [01.04.0550.00

Relationship between cyclohexyl-alkanoic acids and the acidothermophilic bacterium Alicyclobacillus spp.: Evidence from Brazilian oils

Previous analyses of lacustrine saline petroleum from the Campos Basin (Southeastern Brazil), and marine evaporitic petroleum from the Sergipe-Alagoas Basin (Northeastern Brazil) revealed the presence of a series of alkyl-cyclohexanes and cyclohexyl-alkanoic acids. The origin of these compounds in petroleum has not been discussed in the literature, but bibliographic research revealed that cyclohexyl-alkanoic acids are the main constituents of the lipidic membranes of the bacteria Alicyclobacillus spp. The present study characterized the distribution of omega-cyclohexyl-undecanoic acid in Brazilian marine evaporitic and lacustrine saline oils from the Sergipe-Alagoas and Campos basins, and correlated the occurrence of this class of compounds to the presence of Alicyclobacillus spp. in the formation water and oil samples from the Campos Basin. (c) 2005 Elsevier Ltd. All rights reserved.36101443145