Amycolatopsis rhizosphaerae sp. Nov., isolated from rice rhizosphere soil

Abstract

A novel actinomycete, designated strain DH51B-4-3T, which formed long chains of spherical spores borne on the tip of sporophores arising from the aerial mycelium, was isolated from rice rhizosphere soil. The isolate contained meso-diaminopimelic acid in the cell-wall peptidoglycan. The whole-cell sugars of strain DH51B-4-3T were arabinose, galactose, glucose, rhamnose and ribose. The phospholipids in the cell membrane were phosphatidylethanolamine, phosphatidyl methylethanolamine, diphosphatidylglycerol and phosphatidylinositol. The major menaquinone was MK-9(H4). The main cellular fatty acids were iso-C16:0 and cyclo-C17:0. The G+Ccontent of the genomic DNA was 68.2mol%. Phylogenetic analysis using 16S rRNA gene sequences revealed that strain DH51B-4-3T should be classified in the genus Amycolatopsis and closely related to Amycolatopsis dongchuanensis YIM 75904T (98.06%) and Amycolatopsis sacchari DSM 44468T (97.77%). The result of DNA-DNA hybridization and some physiological and biochemical properties indicated that strain DH51B-4-3T could be readily distinguished from its closest phylogenetic relatives. On the basis of these phenotypic and genotypic data, this strain represents a novel species, for which the name Amycolatopsis rhizosphaerae sp. nov. is proposed. The type strain is DH51B-4-3T (=TBRC 6029T=NBRC 112509T).