Transfer of 'Thermoactinomyces glaucus' IFO 12530 and 'Thermoactinomyces monosporus' IFO 14050 to the genus Saccharomonospora as members of Saccharomonospora glauca

Two available strains of 'Thermoactinomyces glaucus' and 'Thermoactinomyces monosporus,' 'T. glaucus' IFO 12530 and 'T, monosporus' IFO 14050, were co nsidered not to be members of the genus Thermoactinomyces and that they bel onged to the genus Saccharomonospora on the basis of the colors of colonies and 16S rDNA sequences. Some chemotaxonomic characteristics also showed th at the two strains belong to the genus Saccharomonospora, The two strains c ontained meso-diaminopimelic acid, galactose, and arabinose in the cell wal l and MK-9(H-4) as the predominant menaquinone. The genomic DNAs of the two strains had a G+C content of 69 mol%. The 16S rDNAs of 'T, glaucus' IFO 12 530 and 'T. monosporus' IFO 14050 showed only 1 and 2 bp sequence differenc es, respectively, from that of the type strain of Saccharomonospora glauca. Furthermore, the two strains of 'T, glaucus' and 'T, monosporus' and the t ype strain of S, glauca shared identical 16S-23S rDNA ITS sequences. The le vels of DNA-DNA relatedness confirm that the two strains of 'T, glaucus' an d 'T. monosporus' are members of Saccharomonospora glauca, Therefore it is proposed that 'T. glaucus' IFO 12530 and 'T, monosporus' IFO 14050 should b e considered as strains belonging to Saccharomonospora glauca.