Actinomycetologica Copyright 2007 The Society for Actinomycetes Japan
Krasilnikovia gen. nov., a new member of the family Micromonosporaceae and description of Krasilnikovia cinnamonea sp. nov.
Ismet Ara1;2 and Takuji Kudo1 1Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center 2-1 Hirosawa, Wako, Saitama 351-0198, Japan 2Present address: Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan (Received Sep. 12, 2006 / Accepted Nov. 24, 2006 / Published May 18, 2007)
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-C16:0 (44.0%), iso-C14:0 (13.0%) and unsaturated C18:1 (!9c) (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 Advancecontent 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 strainView is 3-54(41)T (=JCM 13252T = MTCC 8094T). INTRODUCTION species form spore chains; Verrucosispora species do not form aerial mycelia or sporangia; Actinoplanes, Dactylo- The family Micromonosporaceae was first described by sporangium, Pilimelia, Catenuloplanes, Couchioplanes and Krasil’nikov1) on a morphological basis and was amended Spirilliplanes sporesProofs show motility; and Catenuloplanes by Goodfellow et al.2), who added the genera Actinoplanes, and Couchioplanes species have lysine instead of meso- Dactylosporangium and Pilimelia on the basis of numerical diaminopimelic acid as the diamino acid of the peptido- and chemical analyses. Koch et al.3) amended the descrip- glycan. tion of the family to reflect its phenotypic and chemo- During taxonomic studies of rare actinomycetes, strain taxonomic heterogeneity. Later, Stackebrandt et al.4) 3-54(41)T, which formed spherical pseudosporangial further amended the family on the basis of phylogenetic structures on substrate mycelia, was isolated from sandy clustering of 16S rDNA/rRNA sequences and the presence soil samples from Chokoria, Cox’s Bazar, Bangladesh. of taxon-specific 16S rDNA/rRNA signature nucleotides. On the basis of its 16S rDNA sequences, the isolate falls At present, the family Micromonosporaceae comprises 15 phylogenetically within the family Micromonosporaceae genera: Micromonospora5), Actinoplanes6), Pilimelia7), adjacent to the genus Couchioplanes and Actinoplanes Dactylosporangium8), Catellatospora9), Catenuloplanes10), globisporus. Therefore, we propose that the isolate Couchioplanes11), Spirilliplanes12), Verrucosispora13), should be included in a new genus, Krasilnikovia, the Virgisporangium14), Asanoa15), Longispora16), Salinis- name being derived from the Russian microbiologist N. A. pora17), Actinocatenispora18) and Polymorphospora19), each Krasil’nikov. genus having distinctive morphological and/or chemo- taxonomic characteristics. Micromonospora and Salinis- MATERIALS AND METHODS pora species form single spores on short or long spor- ophores; Actinoplanes, Dactylosporangium, Pilimelia and Strain 3-54(41)T was isolated from sandy soil collected Virgisporangium species form sporangia; Catellatospora, at a forest-side waterfall in Chokoria, Cox’s Bazar, Asanoa, Catenuloplanes, Couchioplanes, Longispora, Bangladesh. The strain was isolated using the standard Spirilliplanes, Actinocatenispora and Polymorphospora dilution plate method and grown on humic acid-vitamin