Actinoplanes solisilvae sp. nov., Isolated from Birch Forest Soil

Abstract

A novel actinomycete, designated strain LAM7112^T, was isolated from soil sample collected from a birch forest in Xinjiang Uygur Autonomous Region, China. The new isolate was found to be able to grow at 20-45 °C (optimum: 35 °C), pH 5.0-10.0 (optimum: 7.0) and in the presence of 0-10.0% (optimum: 3.0%) (w/v) NaCl. The isolate formed very scantily irregular sporangia containing motile spores on the substrate mycelium. Phylogenetic analysis of 16S rRNA gene sequences indicated that the new isolate was closely related to members of the family Micromonosporaceae, with highest similarites to Actinoplanes ferrugineus X-14695^T (97.4%), Micromonospora zamorensis DSM 45600^T (97.3%) and Micromonospora aurantiaca ATCC 27029^T (97.3%). In the phylogenetic trees, strain LAM7112^T formed a stable phylogenetic subclade within the genus Actinoplanes. The genomic DNA G + C content was 70.0 mol%. The major fatty acids (> 10%) were determined to be iso-C_16:0, anteiso-C_15:0 and anteiso-C_17:0. The predominant menaquinones were identified as MK-9 (H₂), MK-9 (H₄) and MK-9 (H₆). The major polar lipids were found to be diphosphatidylglycerol, phosphatidylinositol and phosphatidylethanolamine. The diagnostic amino acid of the cell wall peptidoglycan was determined to be meso-diaminopimelic acid. The diagnostic sugars in cell hydrolysates were determined to be glucose and ribose. On the basis of its phenotypic, phylogenetic and chemotaxonomic characteristics, strain LAM7112^T (= CGMCC 4.7580^T = JCM 32512^T) is proposed to represent the type strain of a novel species of the genus Actinoplanes, for which the name Actinoplanes solisilvae is proposed.