Deoxyribonucleic Acid Relatedness of Bacillus circulans Jordan 1890 Strains

Abstract

Deoxyribonucleic acid reassociation measurements revealed that 50 of 111 Bacillus circulans Jordan 1890 strains examined could be separated into 10 groups of genetically related organisms. The results of deoxyribonucleic acid relatedness studies and phenotypic comparisons suggested that five of these groups were hitherto undescribed species and that four others probably represented previous ly, but inadequately, described species. The tenth group, which included the type strain, represented the species B. circulans sensu stricto. Our data show that B. circulans and Bacillus macerans Schardinger 1905 are genetically and phenotypically distinct species. Thus, the phenotypic heterogeneity of the species B. circulans sensu lato is not due to inherent variability of genetically related strains but rather is due to inclusion of genetically unrelated organisms in this taxon.