Amycolatopsis stemonae sp. nov., isolated from a Thai medicinal plant.

Abstract

A novel actinomycete, strain ST1-08T, was isolated from the stem of Stemona sp. in Thailand. The taxonomic position of this isolate was determined by using a polyphasic approach. Strain ST1-08T contained meso-diaminopimelic acid in the cell-wall peptidoglycan, and arabinose and galactose as diagnostic sugars of the whole-cell hydrolysate, which are typical properties of members of the genus Amycolatopsis. Strain ST1-08T grew at 15-40 °C, pH 6-9 and on 5 % (w/v) NaCl. Gelatin liquefaction, starch hydrolysis and skimmed milk peptonization were positive. The strain utilized l-arabinose, d-glucose, glycerol, myo-inositol, d-mannitol and l-rhamnose. The predominant menaquinone was MK-9(H4) and the major cellular fatty acids were iso-C16 : 0 and iso-C15 : 0.The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxyl-phosphatidylethanolamine, phosphatidylinositol and phosphatidylglycerol. The 16S rRNA gene sequence analysis revealed that the strain was closely related to Amycolatopsis pretoriensis JCM 12673T (98.99 %) and Amycolatopsis lexingtonensis JCM 12672T (98.87 %). The DNA G+C content of strain ST1-08T was 71.2 mol%. The DNA-DNA relatedness values among strain ST1-08T, A. pretoriensis JCM 12673T and A. lexingtonensis JCM 12672T were lower than 70 %, the cut-off level for assigning strains to the same species. On the basis of phenotypic and genotypic characteristics, strain ST1-08T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis stemonae is proposed. The type strain is ST1-08T( = JCM 30050T = PCU 339T = TISTR 2278T).