In the course of screening novel secondary metabolites, an acidophilic actinomycete strain, designated Aac-30T, was isolated from forest soil and subjected to a polyphasic taxonomic characterization study. It grew well on media in which the pH ranged from 4 to 6, but not on medium with pH adjusted to 7. It possessed ll-diaminopimelic acid and glycine in the cell-wall peptidoglycan, MK-9(H6) and MK-9(H8) as major isoprenoid quinones, iso-C16 : 0 and anteiso-C17 : 0 as major cellular fatty acids, and phosphatidylglycerol and phosphatidylinositol as polar lipids. The G+C content of the genomic DNA was 69.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that the organism belonged to the family Catenulisporaceae and consistently formed a monophyletic cluster with members of the genus Catenulispora. Physiological, biochemical and chemotaxonomic data revealed that this novel organism could be readily differentiated from recognized members of the genus Catenulispora and that it merits separate species status. Based on the phenotypic and genetic evidence presented, strain Aac-30T is considered to represent a novel species of the genus Catenulispora, for which the name Catenulispora rubra sp. nov. is proposed. The type strain is Aac-30T (=NBRC 101179T=DSM 44948T).
Two novel Microbacterium species are described on the basis of phenotypic, chemotaxonomic and genotypic studies. The two strains, designated YM10-847T and YM11-607T, were isolated from river sediment and unidentified hydroid, respectively, of a marine lake. The strains were Gram-positive, catalase-positive bacteria with l-ornithine as the diagnostic diamino acid of the peptidoglycan. The acyl type of the peptidoglycan was N-glycolyl. The major menaquinones were MK-10 and MK-11 for YM10-847T, and MK-11 and MK-12 for YM11-607T. Mycolic acids were not detected. The DNA G+C content of strains YM10-847T and YM11-607T was 67.8 and 71.6 mol%, respectively. Comparative 16S rRNA gene sequence analysis revealed that the two strains belong to the genus Microbacterium. DNA–DNA relatedness data showed that YM10-847T and YM11-607T are two novel species of this genus. On the basis of these results, strains YM10-847T and YM11-607T represent two novel species of the genus Microbacterium, for which the names Microbacterium sediminicola sp. nov. and Microbacterium marinilacus sp. nov. are proposed. The type strains are YM10-847T (=MBIC08264T=DSM 18905T) and YM11-607T (=MBIC07778T=DSM 18904T), respectively.