Sporolactobacillus Shoreicorticis Sp Nov., A Lactic Acid-Producing Bacterium Isolated From Tree Bark

A Gram-stain-positive, lactic acid-producing bacterium designed strain MK21-7(T), 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 MK21-7(T) were anteiso-C-17 : 0, iso-C-16 : 0, anteiso-C-15 : 0 and C-18 : 1 omega 9c. 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. MK21-7(T) showed the highest 16S rRNA gene sequence similarity to Sporolactobacillus terrae NBRC 101527(T) with 98.4% similarity and exhibited 97.6% similarity with Sporolactobacillus kofuensis NRIC 0334(T), 97.5% with Sporolactobacillus laevolacticus NRIC 0361 T, 97.3% with Sporolactobacillus nakayamae subsp. nakayamae NRIC 0347(T) and 97.1% with Sporolactobacillus nakayamae subsp. racemicus NBRC 101524(T). Analysis of the phylogenetic relationship based on 16S rRNA and gyrB gene sequencing revealed that the position of MK21-7(T) 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 101527(T) 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, MK21-7(T) 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 MK21-7(T) (= NBRC 111517(T) = LMG 29111(T) = TISTR 2466(T)).