Thermotoga elfii sp. nov., a novel thermophilic bacterium from an African oil-producing well.

A thermophilic, glucose-fermenting, strictly anaerobic, rod-shaped bacterium, strain SEBR 6459T (T = type strain), was isolated from an African oil-producing well. This organism was identified as a member of the genus Thermotoga on the basis of the presence of the typical outer sheath-like structure (toga) and 16S rRNA signature sequences and its ability to grow on carbohydrates (glucose, arabinose, fructose, lactose, maltose, and xylose). Major differences in its 16S rRNA gene sequence, its lower optimum temperature for growth (66 degrees C), its sodium chloride range for growth (0 to 2.8%), its lack of lactate as an end product from glucose fermentation, and its peritrichous flagella indicate that strain SEBR 6459T is not similar to the three previously described Thermotoga species. Furthermore, this organism does not belong to any of the other genera related to the order Thermotogales that have been described. On the basis of these findings, we propose that this strain should be described as a new species, Thermotoga elfii. The type strain of T. elfii is SEBR 6459 (= DSM 9442).