A POLYPHASIC TAXONOMIC GEOGRAPHICAL AREA STUDY OF THERMOPHILIC BACILLI FROM A WIDE GEOGRAPHICAL AREA

Two hundred and thirty-four thermophilic Bacillus strains isolated fro m geographically widespread locations were examined by phenotypic char acterisation followed by numerical analysis. The strains were distribu ted between eighteen cluster-groups which were subsequently evaluated in DNA base composition and DNA sequence homology studies. The inclusi on of type and reference strains unambiguously identified strains rela ted to B. licheniformis, B. pallidus, B. smithii, B. stearothermophilu s, B. thermocloacae and B. thermoglucosidasius. Other reference strain s included in distinctive groups were 'B. caldotenax', together with ' B. caldovelox' and 'B. caldolyticus', B. kaustophilus and 'B. thermode nitrificans'. An emended description of B. kaustophilus is provided. I t is proposed that 'B. caldorenax' and 'B. thermodenitrificans' should be accepted as validly described species. Members of other clusters t hat appeared to have distinctive characteristics, including beta-gluca nase production and the ability to degrade tyrosine, may provide the n uclei of further novel species.