COMPARATIVE-STUDIES ON 5S RNA SEQUENCES AND DNA-DNA HYBRIDIZATION OF OBLIGATELY AND RESTRICTED FACULTATIVELY METHYLOTROPHIC BACTERIA

Results of DNA-DNA hybridization and 5S rRNA sequencing studies on som e strains of obligately and restricted facultatively methylotrophic ba cteria support earlier proposed establishment of the genera Methylophi lus, Methylobacillus and Methylovorus. Comparative analysis permitted us to determine the taxonomic positions of the strains previously clas sified as members of the genera Methanomonas, Methylomonas, Methanolom onas, Protaminobacter and Pseudomonas and to clarify the intrageneric compositions of these genera. Also, our phylogenetic analysis confirme d that obligately and restricted facultatively methylotrophic bacteria constitute a separate branch within the beta-subdivision of the Prote obacteria and are genetically distinct from other methylotrophic bacte ria.