Cohnella plantaginis sp. nov., a novel nitrogen-fixing species isolated from plantain rhizosphere soil

Abstract

A novel bacterium capable of fixing nitrogen was isolated from plantain rhizosphere soil in China. The isolate, designated YN-83(T), is Gram-positive, aerobic, motile and rod-shaped (0.4-0.6μm×1.9-2.6μm). Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain YN-83(T) was a member of the genus Cohnella. High similarity of 16S rRNA gene sequence was found between YN-83(T) and Cohnella ginsengisoli DSM18997(T) (97.99%), whereas the similarity was below 96.0% between YN-83(T) and the other Cohnella species. DNA-DNA relatedness between strain YN-83(T) and C. ginsengisoli DSM18997(T) was 27.4±6.2%. The DNA G+C content of strain YN-83(T) was 59.3mol%. The predominant isoprenoid quinone was MK-7 and the major fatty acids were anteiso-C(15:0) (44.3%), iso-C(15:0) (11.3%), iso-C(16:0) (18.6%) and C(16:0) (7.7%). The polar lipids of strain YN-83(T) consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, lyso- phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. On the basis of phenotypic and chemotaxonomic properties, 16S rRNA gene sequence, G+C content and DNA-DNA hybridization, strain YN-83(T) represents a novel species of the genus Cohnella, for which the name Cohnella plantaginis sp. nov. (type strain YN-83(T)=DSM 25424(T)=CGMCC 1.12047(T)) is proposed.