Promicromonospora viridis sp. nov., a novel actinomycete isolated from soil.

Abstract

Two Gram-stain positive, aerobic actinomycete strains, designated NEAU-JGR1T and NEAU-JGC41, were isolated from soil collected from Fairy Lake Botanical Garden in Shenzhen, Guangdong Province, south of China. The 16S rRNA gene sequences analysis showed that the two strains exhibited 99.5% 16S rRNA gene sequence similarity with each other and were closely related to Promicromonospora thailandica JCM 17130T (99.4, 99.3%) and Promicromonospora citrea DSM 43110T (99.2, 99.2%). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the two strains clustered together and formed a cluster with P. thailandica JCM 17130T and P. citrea DSM 43110T. Both strains were observed to contain MK-9(H4) and MK-9(H2) as predominant menaquinones. Their whole cell sugar profiles were found to main contained rhamnose, ribose, glucose and galactose. The phospholipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, glycophosphatidylinositol, phosphatidylinositol mannoside, an unidentified glycolipid and an unidentified phospholipid. The predominant cellular fatty acids for the two strains were identified as anteiso-C15:0, iso-C15:0 and anteiso-C17:0. The DNA-DNA hybridization value between strains NEAU-JGR1T and NEAU-JGC41 was 85.1 ± 0.3%, and the values between the two strains and their close phylogenetic relatives were well below 70%, supporting the conclusion that they represent a distinct genomic species. An array of phenotypic characteristics also differentiated the isolates from closely related species. On the basis of the genetic and phenotypic properties, strains NEAU-JGR1T and NEAU-JGC41 can be classified as representatives of a novel species of the genus Promicromonospora, for which the name Promicromonospora viridis sp. nov., is proposed. The type strain is NEAU-JGR1T (= DSM 105536T = CGMCC 4.7473T).