RT Journal Article SR Electronic(1) A1 NAKAMURA*, L. K. A1 SWEZEY, J.YR 1983 T1 Taxonomy of Bacillus circulans Jordan 1890: Base Composition and Reassociation of Deoxyribonucleic Acid JF International Journal of Systematic and Evolutionary Microbiology, VO 33 IS 1 SP 46 OP 52 DO https://doi.org/10.1099/00207713-33-1-46 PB Microbiology Society, SN 1466-5034, AB The guanine-plus-cytosine (G+C) contents of 123 strains previously identified as Bacillus circulans Jordan 1890 were determined. Of the strains examined, only 18 had G+C contents of 37 to 41 mol%, a range that included the G+C content (38.1 mol%) of the type strain. A major portion of the strain (93 strains) had G+C contents in the range from 46 to 55 mol%. For seven strains the G+C contents ranged from 42 to 45 mol%, and for another small group of five strains the G+C contents ranged from 56 to 61 mol%. Deoxyribonucleic acid reassociation studies revealed that 10 of the 18 strains with G+C contents of 37 to 41 mol% were closedly related genetically to each other and to the type strain. This genetically related group was phenotypically quite homogeneous. Our results strongly suggested that most of the strains were misclassified as B. circulans. Consequently, the phenotypic heterogeneity of the species B. circulans Jordan 1890 was not due to inherent variability of genetically related strains, but to variability introduced by inclusion of genetically unrelated organisms., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-33-1-46