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A novel anaerobic, chemo-organotrophic bacterium, designated VNs36(T), was isolated from a well that collected water from a deep saline aquifer used for underground gas storage at a depth of 830 m in the Paris Basin, France. Cells were curved motile rods or vibrios (3.0-5.0x0.5 microm). Strain VNs36(T) grew at temperatures between 20 and 50 degrees C (optimum 37 degrees C) and at pH values between 5.0 and 9.0 (optimum 6.9). It did not require salt for growth, but tolerated up to 20 g NaCl l(-1) (optimum 2 g l(-1)). In the presence of sulfate, strain VNs36(T) used lactate, formate and pyruvate as carbon and energy sources. The main fermentation products from lactate were acetate, H(2) and CO(2). Sulfate, thiosulfate and sulfite were used as electron acceptors, but not sulfur. The genomic DNA G+C content of strain VNs36(T) was 67.2 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain VNs36(T) was affiliated with the family Desulfovibrionaceae within the class Deltaproteobacteria. On the basis of 16S rRNA gene sequence comparisons, DNA G+C content and the absence of desulfoviridin in cell extracts, it is proposed that strain VNs36(T) be assigned to a new genus, Desulfocurvus gen. nov., as a representative of a novel species, Desulfocurvus vexinensis sp. nov. The type species of this genus is Desulfocurvus vexinensis with the type strain VNs36(T) (=DSM 17965(T)=JCM 14038(T)).

A novel sulfate-reducing bacterium was isolated from a well that collected water from a deep aquifer at a depth of 430 m in the Paris Basin, France. The strain, designated B7-43T, was made up of vibrioid cells that were motile by means of a single polar flagellum. Cells contained desulfoviridin. In the presence of sulfate, the following substrates were used as energy and carbon sources: lactate, pyruvate, malate, fumarate, ethanol, butanol, acetate/H2 and glycine. Sulfite and thiosulfate were also used as electron acceptors in the presence of lactate. In the absence of electron acceptors, pyruvate, malate and fumarate were fermented. Optimal growth was obtained in 1 g NaCl l(-1) and at pH 7. On the basis of 16S rRNA gene sequence analysis, the isolate was most closely related to members of the genus Desulfovibrio (90 % similarity). It is thus proposed that strain B7-43T (=DSM 16056T=ATCC BAA-905T) represents a novel species within this genus, Desulfovibrio putealis sp. nov.