[The level of DNA homology in species of the genus Cytophaga].

Nucleotide composition, genome size and DNA homologies were studied for strains Cytophaga johnsonae DSM 425, C. pectinovora DSM 6368, C. saccharophyla DSM 1811, C. aquatilis DSM 2063, C. flevensis DSM 1076, C. lytica ATCC 23 178, C. arvensicola DSM 3695, C. heparina DSM 2356. A considerable difference in GS-bases level between species of genus Cytophaga (33.3-34.9 mol %) and incertae sedis species (C. heparina and C. arvensicola) (45.0-46.7 mol. %) was shown. The differentiation between freshwater and soil, on the one hand, and seawater species, on the other hand, was determined. The degree of DNA-resemblance between them was 2-13%. The existence of relationship between freshwater and soil species was demonstrated. The homology in DNA of freshwater and soil species (C. johnsonae, C. pectinovora and C. saccharophyla) was 22-37%. The heterogeneity of genus Cytophaga and the necessity of its revision are supported.