Fusibacter paucivorans gen. nov., sp nov., an anaerobic, thiosulfate-reducing bacterium from an oil-producing well

A strictly anaerobic, halotolerant, spindle-shaped rod, designated strain SEER 4211(T), was isolated from an African saline oil-producing weil, Cells stain Grampositive, which was confirmed by electron microscopy observations. Strain SEER 4211(T) was motile by means of one to four peritrichous flagella, had a G + C content of 43 mol% and grew optimally at 37 degrees C, ph 7.3. with 0 to 3 % (w/v) NaCl. It utilized a limited number of carbohydrates (cellobiose, glucose, fructose, mannitol and ribose) and produced acetate, butyrate, CO2 and H-2 as end products from glucose fermentation. It reduced thiosulfate to sulfide. In the presence of thiosulfate, a decrease in butyrate and an increase in acetate production was observed. Phylogenetically, strain SEER 4211(T) was related to members of the low G + C Clostridiales order with Clostridium halophilum as the closest relative (16S rDNA sequence similarity of 90 %). On the basis of phenotypic, genotypic and phylogenetic characteristics of the isolate, it is proposed to designate it as a new species of a new genus, Fusibacter gen. nov., as Fusibacter paucivorans sp. nov. The type strain is SEER 4211(T) (= DSM 12116(T)).