Geosteranes: Identification and synthesis of a novel series of 3-substituted steranes

A novel series of 3-alkyl and 3-carboxyalkyl-5 beta(H)-steranes 7-10 along with a full homologous series of carboxyalkyl-sterane (C-1 to C-6) 4-6 with 3 alpha(H)5 alpha(H) configuration have been identified in marine-evaporitic oils from Fazenda Belim, Potiguar Basin (Brazil) on the basis of mass spectral interpretation. The synthesis of enantiomerically pure 3 alpha-alkyl-5 beta(H)-cholestane and 3 beta-alkyl-5 alpha(H)-cholestane standards and their coinjection with petroleum fractions confirmed the structural assignments. (C) 1997 Elsevier Science Ltd.264198478779

Diversity analyses of microbial communities in petroleum samples from Brazilian oil fields

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Recent studies of oil fields have shown that the microbial diversity is represented by bacteria and archaea of wide distribution, and that many of these organisms have potential to metabolize organic and inorganic compounds. Biodegradation processes in oil industry are of great relevance, since it may be related with the loss of petroleum quality and can bring problems during production. The aim of this study was to compare the microbial communities present in biodegraded (GMR75) and non-biodegraded (PTS1) terrestrial oils from the Potiguar Basin (RN, Brazil) by using cultivation (microbial enrichments and isolation) and molecular approaches (16S rRNA gene libraries). The cultivated microorganisms recovered were affiliated with the phyla Actinobacteria, Firmicutes and Proteobacteria. Both bacterial 16S rRNA gene libraries revealed a great diversity, encompassing representatives from 8 different phyla (Actinobacteria, Bacteroidetes, Deferribacteres, Spirochaetes, Firmicutes, Proteobacteria, Thermotogae and Synergistetes) for the GMR75 sample, and from 5 different phyla (Actinobacteria, Chloroflexi, Firmicutes, Proteobacteria and Thermotoga) for the PTS1 sample. The archaeal 16S rRNA gene library was obtained only for GMR75 oil and all phylotypes were affiliated with the family Methanomicrobiaceae. Diversity results suggest that methanogenesis is the dominant terminal process for hydrocarbon degradation in GMR oil field, driven by anaerobic biodegradation. (C) 2012 Elsevier Ltd. All rights reserved.81SI5770PETROBRASCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Analysis of the composition of bacterial communities in oil reservoirs from a southern offshore Brazilian basin

The aim of this study was to characterize and compare the bacterial community structure of two distinct oil samples from a petroleum field in Brazil by using both molecular, based on the construction of 16S rRNA gene libraries, and cultivation methods. Statistical comparisons of libraries based on Amplified Ribosomal DNA Restriction Analysis (ARDRA) data revealed no significant differences between the communities recovered in the non-biodegraded (NBD) and highly biodegraded oils (HBD). BlastN analysis of the 16S rRNA gene sequences representative of distinct ribotypes from both oils showed the presence of nine different bacterial genera in these samples, encompassing members of the genera Arcobacter, Halanaerobium, Marinobacter, Propionibacterium, Streptomyces, Leuconostoc, Acinetobacter, Bacillus and Streptococcus. Enrichments obtained using oil as inoculum and sole carbon source yielded bacterial isolates showing high 16S rRNA gene sequence similarity with Achromobacter xylosoxidans, Bacillus subtilis, Brevibacillus sp., Dietzia sp. and Methylobacterium sp. Comparison between the data obtained using cultivation-independent and enrichment cultures suggests that different selection of community members may occur when using distinct approaches. All the organisms found, except for Leuconostoc sp. and Streptococus sp., have been previously reported in the literature as hydrocarbon degraders and/or associated to oil field environments.91325326

3-alkyl and 3-carboxyalkyl steranes in marine evaporitic oils of the Potiguar Basin, Brazil

The geochemical characterization of marine evaporitic oils from the Fazenda Belem oil field, Potiguar Basin, Brazil showed good correlation between both acidic and neutral fractions, and led to the identification of several biomarkers including the homologous series of 3-alkyl- and 3-carboxyalkyl-5 alpha(H) steranes and also the new series of 3-alkyl- and 3-carboxyalkyl-5 beta(H) steranes. These compounds were identified using GC/MS and their structures were confirmed by coinjection with synthetic standards. A minor series of 4-carboxyalkyl steranes was also detected. The analysis of the acidic biomarkers allowed a more accurate evaluation of maturation, biodegradation and migration of the studied oils. (C) 1999 Elsevier Science B.V. All rights reserved.1584167112

The potential for hydrocarbon biodegradation and production of extracellular polymeric substances by aerobic bacteria isolated from a Brazilian petroleum reservoir

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Extracellular polymeric substances (EPS) can contribute to the cellular degradation of hydrocarbons and have a huge potential for application in biotechnological processes, such as bioremediation and microbial enhanced oil recovery (MEOR). Four bacterial strains from a Brazilian petroleum reservoir were investigated for EPS production, emulsification ability and biodegradation activity when hydrocarbons were supplied as substrates for microbial growth. Two strains of Bacillus species had the highest EPS production when phenanthrene and n-octadecane were offered as carbon sources, either individually or in a mixture. While Pseudomonas sp. and Dietzia sp., the other two evaluated strains, had the highest hydrocarbon biodegradation indices, EPS production was not detected. Low EPS production may not necessarily be indicative of an absence of emulsifier activity, as indicated by the results of a surface tension reduction assay and emulsification indices for the strain of Dietzia sp. The combined results gathered in this work suggest that a microbial consortium consisting of bacteria with interdependent metabolisms could thrive in petroleum reservoirs, thus overcoming the limitations imposed on each individual species by the harsh conditions found in such environments.27615131518Petrobras, BrazilFINEP, BrazilFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)DAADGerman Research Foundation (DFG) [WI 2094/2-1, MI 157/21-1]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [08/52355-9]German Research Foundation (DFG) [WI 2094/2-1, MI 157/21-1

Evidence for euphotic zone anoxia during the deposition of Aptian source rocks based on aryl isoprenoids in petroleum, Sergipe-Alagoas Basin, northeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Four crude oil samples from the Sergipe-Alagoas Basin, northeastern Brazil, were analyzed using full scan gas chromatography-quadrupole mass spectrometry (GC-qMS) for biomarkers, in order to correlate them using aromatic carotenoids thereby enhancing knowledge about the depositional environment of their source rocks. The geochemical parameters derived from saturated fractions of the oils show evidence of little or no biodegradation and similar thermal maturation (Ts/(Ts + Tm) for terpanes, C-29 alpha beta beta/(alpha beta beta + alpha alpha alpha), C-27, and C-29 20S/(20S + 20R) for steranes). Low pristane/phytane ratios and the abundance of gammacerane and beta-carotane are indicative of an anoxic and saline depositional environment for the source rocks. Moreover, we identified a large range of diagenetic and catagenetic products of the aromatic carotenoid isorenieratene, including C-40, C-33, and C-32 diaryl isoprenoids and aryl isoprenoid derivatives with short side chains and/or additional rings. These results indicate anoxia in the photic zone during the deposition of the source rocks. (c) 2013 Published by Elsevier Ltd.6394104Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)PETROBRASUFPIConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Propyl ergostanoic acids: Possible new indicator for oil biodegradation

Representative oils having similar maturity, derived from a saline lacustrine source rock and accumulated at different depths in stacked reservoirs in the Campos Basin, Brazil were selected for study Geological conditions allowed the development of distinct extents of biodegradation that Increase from the deeper to the shallower reservoirs as shown by increased sulfur content, decreased saturated hydrocarbons and lower APl gravity. Gas chromatography (GC). GC-mass spectrometry (GC-MS) and GC-MS-MS show the presence of hopanoic acids with the C(32) beta beta R biological configuration and a suite of 3-propylsteranoic acids with the carboxylic function in the C-17 side chain, suggesting that the compounds are proxies for biodegradation Systematic variation in the relative abundance of these new biomarkers with the extent of biodegradation were also observed To the best of our knowledge, this is the first report of the occurrence of 3-propylergostanoic compounds in geological samples (C) 2009 Elsevier Ltd. All rights reserved414325339Petroleo Brasileiro S.A (Petrobras

Petroleomics by EASI(+/-) FT-ICR MS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)An ambient ionization/desorption technique, namely, easy ambient sonic-spray ionization mass spectrometry (EASI), has been applied to crude oil samples. From a single droplet of the sample placed on an inert surface, EASI(+/-) is shown to promote efficient desorption and ionization of a myriad of polar components via the action of its cloud of very minute supersonic bipolar charged droplets. The gaseous [M + H](+) and [M - H](-) ions concurrently formed by EASI(+/-) were analyzed by Fourier transform mass spectrometry (FT-ICR MS), and a total of similar to 6000 acidic and basic components have been attributed. EASI(+/-) FT-ICR MS of crude oils is show to be almost as fast as ESI(+)/ESI(-) FT-ICR MS, providing similar compositional information of polar components and spectral quality comparable to that of a commercial nonochip-based robotic ESI device. EASI(+/-) requires no sample workup thus eliminating risks of contamination during sample manipulation and memory effects because of carry over in pumping ESI lines. More importantly, EASI(+/-) is a voltage-free ionization technique therefore eliminating risks of redox processes or duality of ionization mechanisms that can be observed in voltage-assisted processes. Data visualization via typical petroleomic plots confirms the similarity of the compositional information provided by EASI(+/-) compared to ESI(+)/ESI(-). The ambient EASI(+/-) FT-ICR MS method requires no voltage switching in changing the ion polarity mode, offering a workup, heating and voltage-free protocol for petroleomic studies performed at open atmosphere directly on the undisturbed crude oil sample.821039903996Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FINEPPetroleo Brasileiro S/A (PETRO-BRAS)Brazilian National Petroleum Agency (ANP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq