RESUMO
A halophilic endospore-forming, sulfate-reducing bacterium was isolated from an oilfield brine in France. The strain, designated SEBR 3139, was composed of long, straight to curved rods. It grew in 1-14% NaCl with an optimum at 6%. On the basis of morphological, physiological and phylogenetical characteristics, strain SEBR 3139 should be classified in the genus Desulfotomaculum. However, it is sufficiently different from the hitherto described Desulfotomaculum species to be considered as a new species. Strain SEBR 3139T (= DSM 11559T) represents the first moderate halophilic species of the genus Desulfotomaculum. The name Desulfotomaculum halophilum sp. nov. is proposed.
Assuntos
Bacilos Gram-Positivos Formadores de Endosporo/classificação , Bactérias Redutoras de Enxofre/classificação , Sequência de Bases , Bacilos Gram-Positivos Formadores de Endosporo/genética , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Bacilos Gram-Positivos Formadores de Endosporo/fisiologia , Dados de Sequência Molecular , Petróleo , Filogenia , RNA Bacteriano , RNA Ribossômico 16S , Análise de Sequência de RNA , Bactérias Redutoras de Enxofre/genética , Bactérias Redutoras de Enxofre/isolamento & purificação , Bactérias Redutoras de Enxofre/fisiologiaRESUMO
Two moderately halophilic sulfate-reducing bacteria were isolated from an African oil pipeline and designated strains SEBR 3640 and SEBR 2840T (T = type strain). Both of these strains possess traits that define the genus Desulfovibrio. The cells of both isolates were motile curved rods that had a single polar flagellum and contained desulfoviridin, and both isolates utilized lactate, pyruvate, malate, fumarate, succinate, and ethanol in the presence of sulfate. Sulfite, thiosulfate, and elemental sulfur were also used as an electron acceptors in the presence of lactate. However, both strains tolerated higher concentrations of NaCl (up to 17%) than all other Desulfovibrio species except Desulfovibrio halophilus, which tolerated a similar level of NaCl. The results of a 16S rRNA gene sequence analysis also placed the designated type strain, strain SEBR 2840, in the genus Desulfovibrio but revealed that this organism was significantly different from D. halophilus and all other validly described Desulfovibrio species. On the basis of our results, we propose that strain SEBR 2840T is a member of a new species of the genus Desulfovibrio, Desulfovibrio gabonensis. The type strain of D. gabonensis is strain SEBR 2840 (= DSM 10636).
Assuntos
Desulfovibrio/classificação , Óleos Combustíveis/microbiologia , Sequência de Bases , DNA Bacteriano , Desulfovibrio/isolamento & purificação , Desulfovibrio/fisiologia , Desulfovibrio/ultraestrutura , Lipídeos/análise , Dados de Sequência Molecular , Oxirredução , Filogenia , Pigmentos Biológicos , RNA Bacteriano , RNA Ribossômico 16S , Sulfatos/metabolismoRESUMO
The occurrence and metabolic capacities of sulfate-reducing bacteria (SRB) were studied in 23 water samples taken from producing wells at 14 different sites. Oil fields in France, the North Sea, and the Gulf of Guinea were selected and classified according to physicochemical parameters (salinity ranging from 0.3 to 120 g.L-1 and temperature between 29 and 85 degrees C). After the distribution of SRB within oil fields was studied, several strains of SRB were isolated and characterized metabolically. Twenty of the thirty-seven strains were not related to any known species. Most of the identified strains were members of the genera Desulfovibrio and Desulfotomaculum by molecular, morphological, and physiological properties.