Actinoplanes rhizophilus sp. nov., an actinomycete isolated from the rhizosphere of Sansevieria trifasciata Prain.

Abstract

A novel actinomycete, designated strain NEAU-A-2T, was isolated from the rhizosphere soil of Sansevieria trifasciata Prain collected from Heilongjiang province, north-east China. The taxonomic status of this organism was established using a polyphasic approach. The isolate formed irregular sporangia containing motile spores on the substrate mycelium. The whole-cell sugars were xylose and galactose. The predominant menaquinones were MK-9(H10), MK-9(H2), MK-10(H2) and MK-10(H4). The major fatty acids were iso-C15 : 0, iso-C16 : 0 and anteiso-C15 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylinositol, three unidentified phospholipids and an unidentified glycolipid. 16S rRNA gene sequence similarity studies showed that strain NEAU-A-2T belongs to the genus Actinoplanes with the highest sequence similarities to Actinoplanes globisporus NBRC 13912T (97.7 % 16S rRNA gene sequence similarity), Actinoplanes ferrugineus IMSNU 22125T (97.5 %), Actinoplanes toevensis MN07-A0368T (97.2 %) and Actinoplanes rishiriensis NBRC 108556T (97.2 %); similarities to type strains of other species of this genus were < 97 %. Two tree-making algorithms showed that strain NEAU-A-2T formed a distinct clade with A. globisporus NBRC 13912T and A. rishiriensis NBRC 108556T. However, low DNA-DNA relatedness values allowed the isolate to be differentiated from the above-mentioned two species of the genus Actinoplanes. Moreover, strain NEAU-A-2T could also be distinguished from the most closely related species by morphological and physiological characteristics. Therefore, in conclusion, isolate NEAU-A-2T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes rhizophilus sp. nov. is proposed. The type strain is NEAU-A-2T ( = CGMCC 4.7133T = DSM 46672T).