Two new species of the genus Micromonospora: Micromonospora chokoriensis sp. nov. and Micromonospora coxensis sp. nov., isolated from sandy soil

Two actinomycete strains, 2-19(6)(T) and 2-30-b(28)(T), which produced single, non-motile noduler to warty spore surfaces, were isolated from sandy soil in Chokoria, Cox's Bazar, Bangladesh. A polyphasic study was carried out to establish the taxonomic position of these strains. Morphological and chemotaxonomic characteristics of these strains coincided with those of the genus Micromonospora. Phylogenetic analysis using 16S rDNA sequences indicated that these strains should be classified in the genus Micromonospora. The 16S rDNA sequence of strain 2-19(6)(T )showed closest similarity to the type strains of M. mirobrigensis (98.9%) and M. carbonacea (98.8%), and the strain 2-30-b(28)(T) to the type strains of M. purpureochromogenes (99.4%), M. halophytica (99.3%) and M. aurantiaca (99.2%). Furthermore, a combination of DNA-DNA hybridization results and some differential physiological and biochemical properties indicated that these strains were distinguished from the phylogenetically closest relatives. These strains therefore represent two novel species, for which the name Micromonospora chokoriensis sp. nov. and Micromonospora coxensis sp. nov. are proposed. The type strains are 2-19(6)(T) (=JCM 13247(T) =MTCC 8535(T)) and 2-30-b(28)(T) (=JCM 13248(T)=MTCC 8093(T)).