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

A novel actinomycete, designated strain NEAU-A-2(T), 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(H-10), MK-9(H-2), MK-10(H-2) and MK-10(H-4). The major fatty acids were iso-C-15 : 0, iso-C-16 : 0 and anteiso-C-15 : 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-2(T) belongs to the genus Actinoplanes with the highest sequence similarities to Actinoplanes globisporus NBRC 13912(T) (97.7 % 16S rRNA gene sequence similarity), Actinoplanes ferrugineus IMSNU 22125(T) (97.5 %), Actinoplanes toevensis MN07-A0368(T) (97.2 %) and Actinoplanes rishiriensis NBRC 108556(T) (97.2 %); similarities to type strains of other species of this genus were <97 %. Two tree-making algorithms showed that strain NEAU-A-2(T) formed a distinct Glade with A. globisporus NBRC 13912(T) and A. rishiriensis NBRC 108556(T). 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-2(T) could also be distinguished from the most closely related species by morphological and physiological characteristics. Therefore, in conclusion, isolate NEAU-A-2(T) represents a novel species of the genus Actinoplanes, for which the name Actinoplanes rhizophilus sp. nov. is proposed. The type strain is NEAU-A-2(T) (=CGMCC 4.7133(T)=DSM 46672(T)).