Cohnella formosensis sp. nov., a xylanolytic bacterium isolated from the rhizosphere of Medicago sativa L

Abstract

A Gram-positive, spore-forming, aerobic, rod-shaped, xylanolytic bacterium designated strain CC-Alfalfa-35T was isolated from the rhizosphere of Medicago sativa L. in Taiwan. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain CC-Alfalfa-35T was affiliated to the genus Cohnella. Strain CC-Alfalfa-35T shared 95.3 % pairwise 16S rRNA gene sequence similarity to the type strain of the type species of the genus Cohnella (Cohnella thermotolerans DSM 17683T) besides showing a similarity of 97.4–93.6 % with other recognized species of the genus Cohnella. The DNA–DNA hybridization value between CC-Alfalfa-35T and Cohnella thailandensis KCTC 22296T was 37.7 %±1.7 % (reciprocal value, 55.7 %±3.0 %). Predominant cellular fatty acids were iso-C16 : 0 and anteiso-C15 : 0. The polar lipid profile constituted diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, lysyl-phosphatidylglycerol, three unidentified phospholipids and three unidentified aminophospholipids. The major respiratory quinone was MK-7 and the DNA G+C content was 58.3 mol%. Strain CC-Alfalfa-35T contained meso-diaminopimelic acid as the major diamino acid in the cell-wall peptidoglycan. Based on the polar lipid and fatty acid profiles, which were in line with those of C. thermotolerans DSM 17683T, coupled with additional distinguishing genotypic, phenotypic and chemotaxonomic features, strain CC-Alfalfa-35T is proposed to represent a novel species within the genus Cohnella, for which the name Cohnella formosensis sp. nov. is proposed. The type strain is CC-Alfalfa-35T ( = JCM 18405T = BCRC 80428T)