%0 Journal Article %A Toyama, H. %A Okanishi, M. %A Umezawa, H. %T Heterogeneity among Whorl-forming Streptomycetes Determined by DNA Reassociation %D 1974 %J Microbiology, %V 80 %N 2 %P 507-514 %@ 1465-2080 %R https://doi.org/10.1099/00221287-80-2-507 %I Microbiology Society, %X SUMMARY DNA-DNA reassociation was studied in order to determine the genomic relatedness among 26 species of whorl-forming streptomycetes. DNA from Streptoverticillium kentuchense isp5052, Stv. abikoense At-37 and Stv. eurocidicum At-267 which showed a low relationship with each other were selected as the reference samples. Relative reassociation values of various streptoverticillia compared with these reference DNAs ranged from 25 to 82% and most were less than 50%. These results suggest that the whorl-forming streptomycetes are a mixture of heterogeneous species when considered at the genomic level. The results also suggest close relationships between Stv. flavopersicum isp5053 and Stv. netropsis isp5259 and also among Stv. ehimense isp5253, Stv. luteoverticillatum isp5038 and Streptomyces reticuli var. latumcidicus At-79. The close relationships within the latter three species were confirmed by their DNA reassociation with Stv. ehimense reference DNA and by thermal dissociation profiles of the hybrid DNAs on membrane filters. From data obtained, the suitability of several diagnostic features as taxonomic criteria was discussed. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-80-2-507