Sporolactobacillus shoreicorticis sp.nov., a lactic acid-producing bacterium isolated from tree bark.

Abstract

A Gram-stain-positive, lactic acid-producing bacterium designed strain MK21-7T, was isolated from tree bark collected from the north east of Thailand. This strain was a facultatively anaerobic spore-forming rod that was catalase-negative. It contained meso-diaminopimelic acid in the cell wall peptidoglycan and had seven isoprene units (MK-7) as the predominant menaquinone. Major fatty acids of MK21-7T were anteiso-C17 : 0, iso-C16 : 0, anteiso-C15 : 0 and C18 : 1ω9c. Polar lipids were phosphatidglycerol, diphosphatidylglycerol, an unknown phospholipid, three unknown glycolipids and an unknown lipid. The results of 16S rRNA gene sequence analysis indicated that it represented a member of the genus Sporolactobacillus. MK21-7T showed the highest 16S rRNA gene sequence similarity to Sporolactobacillus terrae NBRC 101527T with 98.4 % similarity and exhibited 97.6 % similarity with Sporolactobacillus kofuensis NRIC 0334T, 97.5 % with Sporolactobacillus laevolacticus NRIC 0361T, 97.3 % with Sporolactobacillus nakayamaesubsp.nakayamae NRIC 0347T and 97.1 % with Sporolactobacillus nakayamaesubsp.racemicus NBRC 101524T. Analysis of the phylogenetic relationship based on 16S rRNA and gyrB gene sequencing revealed that the position of MK21-7T was clearly separated from all related species of the genus Sporolactobacillus. It had low DNA-DNA relatedness (22.8-57.2 %) with S. terrae NBRC 101527T and related type strains. The DNA G+C content was 43.1 mol%. On the basis of the results of the phenotypic, genotypic and chemotaxonomic studies, MK21-7T should be classified as representing a novel species of the genus Sporolactobacillus for which the name Sporolactobacillus shoreicorticis sp. nov. is proposed. The type strain is MK21-7T (=NBRC 111517T=LMG 29111T=TISTR 2466T).