Streptomyces mimosae sp. nov., an endophytic actinomycete isolated from the root of Mimosa pudica in Thailand

Abstract

An endophytic actinomycete, strain 3MP-10T, isolated from the root of Mimosa pudica was taxonomically studied based upon polyphasic approaches. This strain formed spiral spore chains on aerial mycelia. ll-Diaminopimelic acid, glucose and ribose were found in the whole-cell hydrolysates. It belonged to the genus Streptomyces and was closely related to Streptomyces zhaozhouensis DSM 42101T (98.9 %) and Streptomyces sedi JCM 16909T (98.6 %) based on 16S rRNA gene sequence analysis results. The major menaquinones were MK-10(H8), MK-10(H6) and MK-9(H8). The predominant cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The detected phospholipids were diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phosphatidylethanolamine and phosphatidylglycerol. Strain 3MP-10T had a genome size of 7.2 Mb with a genome G+C content of 73.4 mol%. Results of in silico genome-based similarity analysis revealed ANIb values of 84.94 and 84.77 %, ANIm values of 88.01 and 87.92 %, and dDDH values of 29.9 and 29.6 % when compared with S. zhaozhouensis DSM 42101T and S. sedi JCM 16909T, respectively. Based on the polyphasic approach, digital DNA–DNA relatedness and average nucleotide identity, we propose that the novel actinomycete represents a novel species, Streptomyces mimosae, with type strain 3MP-10T (=JCM 33328T=TISTR 2646T).