THERMOTOLERANT VARIETIES OF BACILLUS-LICHENIFORMIS ISOLATED FROM DESERT ENVIRONMENTS

One hundred and nineteen thermotolerant and thermophilic Bacillus stra ins isolated from solar-heated and non-heated environments in Jordan w ere classified by numerical techniques. Some strains were classified i nto thermophilic taxa which did not equate with established species. H owever, most of the isolates were identified phenotypically as Bacillu s licheniformis, a conclusion supported by the high DNA hybridization which was detected between these strains and a reference strain of thi s species (> 64% at optimal renaturation temperature). Several of the B. licheniformis isolates had a higher ratio of iso-C-15 and iso-C-17 fatty acids to the anteiso equivalents in their membranes than the ref erence strain of B. licheniformis and they grew more strongly at high temperature than the reference strain. This suggests that the B. liche niformis isolates represent thermotolerant variants of this species.