Cohnella endophytica sp. nov., a novel endophytic bacterium isolated from bark of Sonneratia apetala.

Abstract

A Gram-stain-positive, aerobic, rod-shaped, endospore-forming bacterium, designated strain M2MS4P-1T, was isolated from surface-sterilized bark of Sonneratiaapetala sampled in Guangxi, China. The bacterium was characterized by a polyphasic approach to determine its taxonomic position. 16S rRNA gene sequence comparisons revealed that strain M2MS4P-1T belonged to the genus Cohnella and was most closely to Cohnella luojiensis HY-22RT (98.4 % similarity). The average nucleotide identity value and estimated DDH value between strain M2MS4P-1T and the type strain of C. luojiensis HY-22RT were 79.2 and 20.1 %, respectively. Neither substrate nor aerial mycelia were formed, and no diffusible pigments were observed on the media tested. Strain M2MS4P-1T grew in the pH range 6.0-9.0 (optimum, pH 7.0-8.0), at temperatures between 10-37 °C (30 °C) and in 0-1 % (w/v) NaCl (0 %). The predominant isoprenoid quinone in strain M2MS4P-1T was menaquinone-7. The major fatty acids were anteiso-C15 : 0 and iso-C16 : 0. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, lysyl-phosphatidylglycerol, four unidentified aminophospholipids and two unidentified phospholipids. The DNA G+C content was 51.5 mol%. According to the phylogenetic, phenotypic and chemotaxonomic evidence, strain M2MS4P-1T was clearly distinguishable from other species with validly published names in the genus Cohnella and should therefore be classified as a novel species, for which we suggest the name Cohnellaendophytica sp. nov. The type strain is M2MS4P-1T (=KCTC 43011T=CGMCC 1.13745T).