Oceanobacillus endoradicis sp nov., an endophytic bacterial species isolated from the root of Paris polyphylla Smith var. yunnanensis

摘要

A bacterial strain, py1294(T), isolated from a root of Paris polyphylla Smith var. yunnanensis collected from Yunnan province, southwest China, was characterised by using a polyphasic approach to clarify its taxonomic position. Strain py1294(T) was found to be Gram-positive, aerobic, spore-forming, peritrichous flagella and rod shaped. Growth was found to occur in the presence of 0-8 % (w/v) NaCl (optimum 1-3 %), at pH 6.5-9.5 (optimum 8.0) and at 10-42 A degrees C (optimum 30 A degrees C). The major cellular fatty acids were identified as anteiso-C-15:0, anteiso-C-17:0, iso-C-16:0 and iso-C-14:0. The predominant quinone was identified as MK-7 and a minor amount of MK-6 was detected. The diagnostic polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The cell wall peptidoglycan was found to contain meso-diaminopimelic acid. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain py1294(T) forms a well-supported clade with Oceanobacillus damuensis PT-20(T) (97.9 % sequence similarity) within the genus Oceanobacillus, although it also shares a high sequence similarity with Ornithinibacillus contaminans (97.5 %). Crucially, the DNA-DNA relatedness value between strain py1294(T) and O. damuensis PT-20(T) was 29.7 +/- 3.2 %. The G+C content was determined to be 42.3 mol%. On the basis of the phylogenetic and phenotypic data, a novel species Oceanobacillus endoradicis sp. nov. is proposed, with py1294(T) (=DSM 100726(T) = KCTC 33731(T)) as the type strain.