Sphaerisporangium perillae sp. nov., isolated from the root of Perilla frutescens (Linn.) Britt

Abstract

A novel protease-producing actinomycete, designated strain NEAU-ZS1T, was isolated from the root of Perilla frutescens (Linn.) Britt collected from Jiamusi, Heilongjiang, PR China. Comparative 16S rRNA gene sequencing showed that strain NEAU-ZS1T belonged to the genus Sphaerisporangium and was most closely related to ‘ Sphaerisporangium corydalis ’ NEAU-YHS15T (99.2%) and Sphaerisporangium cinnabarinum JCM 3291T (99.0%). Phylogenetic tree analysis revealed that strain NEAU-ZS1T formed a monophyletic clade with ‘ S. corydalis ’ NEAU-YHS15T. The genome size was 9.3 Mbp with a DNA G+C content of 70.3 mol%. Digital DNA–DNA hybridization, average nucleotide identity and average amino acid identity values between the genome sequence of strain NEAU-ZS1T and those of ‘ S. corydalis ’ NEAU-YHS15T (28.6, 83.9 and 79.1 %) and S. cinnabarinum JCM 3291T (18.5, 70.6 and 50.2 %) were below the recommended thresholds for species delineation. The strain formed spherical spore vesicles produced on the aerial hyphae. The cell wall contained meso-diaminopimelic acid and the whole-cell sugars were glucose and madurose. The polar lipids consisted of diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylinositol, an unidentified phospholipid and an unidentified glycolipid. The menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The major fatty acids were iso-C16 : 0, C16 : 1 ω5c, 10-methy C17 : 0 and C17 : 1 ω7c. On the basis of the results of a polyphasic taxonomic study, it is concluded that strain NEAU-ZS1T represents a novel species of the genus Sphaerisporangium , for which the name Sphaerisporangium perillae sp. nov. is proposed. The type strain is NEAU-ZS1T (=CCTCC AA 2021019T= JCM 35655T).