TAXONOMIC STUDIES ON YEAST-LYSING BACTERIA, AND A NEW SPECIES RAROBACTER-INCANUS

From DNA-DNA hybridization and guanine-plus-cytosine (G+C) contents of DNA in 46 strains of yeast-lysing bacteria isolated in Brazil, 15, 28 and 2 strains formed clusters with Japanese isolates YLM-32, YLM-115 and Rarobacter faecitabidus YLM-1T, respectively. The YLM-115 group had lysine as diamino acid in the cell wall peptidoglycan, and they remained unclassified. Rarobacter incanus, sp. nov., was proposed for the YLM-32 group strains. Their G+C contents of DNA were 64.6 65.5 mol%, which were slightly lower than those of R. faecitabidus. The amino acid composition of cell wall peptidoglycan of R. incanus was D-Ala, L-Ala, D-Glu and L-Orn (1:1:2:1), which closely resembled R. faecitabidus, although the latter contained a serine residue which the former did not. Other phenotypic and chemotaxonomic characteristics were almost the same as R. faecitabidus, but R. incanus formed a separate and distinct cluster from R. faecitabidus following DNA-DNA hybridization. The type strain is YLM-32 (JCM 6350).