Thermovirga lienii gen. nov., sp. nov., a novel moderately thermophilic, anaerobic, amino-acid-degrading bacterium isolated from a North Sea oil well.

A novel anaerobic, moderately thermophilic bacterium, strain Cas60314(T), was isolated from hot oil-well production water obtained from an oil reservoir in the North Sea. The cells were Gram-negative, motile, straight rods. The salinity and pH growth optima were 2.0-3.0 % NaCl and 6.5-7.0, respectively. The optimum temperature was 58 degrees C. Strain Cas60314(T) had a fermentative type of metabolism and utilized proteinous substrates, some single amino acids and a limited number of organic acids, but not sugars, fatty acids or alcohols. Cystine and elemental sulfur were reduced to sulfide. The G+C content of the DNA was 46.6 mol%. On the basis of phenotypic and phylogenetic features, it is proposed that this isolate represents a novel genus and species with the name Thermovirga lienii gen. nov., sp. nov. within the family Syntrophomonadaceae. The proposed type strain is strain Cas60314(T) (=DSM 17291(T)=ATTC BAA-1197(T)).