RUBROBACTER XYLANOPHILUS SP-NOV - A NEW THERMOPHILIC SPECIES ISOLATEDFROM A THERMALLY POLLUTED EFFLUENT

One strain of a thermophilic, slightly halotolerant bacterium was isol ated from a thermally polluted industrial runoff near Salisbury, Unite d Kingdom. This organism, strain PRD-1(T) (T=type strain), for which w e propose the name Rubrobacter xylanophilus sp nov, produces short gra m-positive rods and coccoid cells and forms pink colonies. The optimum growth temperature is approximately 60 degrees C. Unusual internal br anched-chain fatty acids (namely, 12-methylhexadecanoic acid and 14-me thyloctadecanoic acid) make up the major acyl chains of the lipids. Th e results of our 16S rRNA sequence comparisons showed that strain PRD- 1(T) is related to Rubrobacter radiotolerans and that these two organi sms form a deep evolutionary line of descent within the gram-positive Bacteria.