Krasilnikovia gen. nov., a new member of the family Micromonosporaceae and description of Krasilnikovia cinnamonea sp. nov.

Abstract

A novel actinomycete strain was isolated from sandy soil collected in Bangladesh. The culture formed pseudosporangia on short sporangiophores directly above the surface of the substrate mycelium. The pseudosporangia developed singly or in clusters and each pseudosporangium contained many non-motile oval to reniform spores with a smooth surface. The strain 3-54(41)^T contained meso-diaminopimelic acid in the cell wall, predominant menaquinone MK-9(H₆), and galactose, mannose, xylose and arabinose in the whole-cell hydrolysate. The diagnostic phospholipid was phosphatidylethanolamine, and branched iso-C_16:0 (44.0%), iso-C_14:0 (13.0%) and unsaturated C_18:1 (ω9c) (12.0%) were detected as the major cellular fatty acids. The acyl type of the peptidoglycan was glycolyl, and mycolic acids were not detected. The G+C content of the DNA was 71 mol%. The chemotaxonomic data indicate that this strain belongs to the family Micromonosporaceae. Phylogenetic analysis based on 16S rDNA sequence data also suggested that the strain 3-54(41)^T falls within this family. On the basis of phylogenetic analysis and the characteristic patterns of signature nucleotides as well as the morphological and chemotaxonomic data, our isolate is proposed to be Krasilnikovia gen. nov., and this strain should be classified as the species Krasilnikovia cinnamonea sp. nov. in the family Micromonosporaceae. The type strain is 3-54(41)^T (=JCM 13252^T = MTCC 8094^T).