Lactobacillus hayakitensis sp. nov., isolated from intestines of healthy thoroughbreds

Two strains, KBL13^T and GBL13, were isolated as one of intestinal lactobacilli from the faecal specimens from different thoroughbreds of the same farm where they were born in Hokkaido, Japan. They were Gram-positive, facultatively anaerobic, catalase-negative, non-spore-forming and non-motile rods. KBL13^T and GBL13 homofermentatively metabolize glucose, and produce lactate as the sole final product from glucose. The 16S rRNA gene sequence, DNA-DNA hybridization, DNA G + C content and biochemical characterization indicated that these two strains, KBL13^T and GBL13, belong to the same species. In the representative strain, KBL13^T, the DNA G + C content was 34.3 mol%. Lactobacillus salivarius JCM 1231^T (= ATCC 11741^T; AF089108) is the type strain most closely related to the strain KBL13^T as shown in the phylogenetic tree, and the 16S rRNA gene sequence identity showed 96.0% (1425/1484 bp). Comparative 16S rRNA gene sequence analysis of this strain indicated that the two isolated strains belong to the genus Lactobacillus and that they formed a branch distinct from their closest relatives, L. salivarius, Lactobacillus aviarius, Lactobacillus saerimneri and Lactobacillus acidipiscis. DNA-DNA reassociation experiments with L. salivarius and L. aviarius confirmed that KBL13^T represents a novel species, for which the name Lactobacillus hayakitensis sp. nov. is proposed. The type strain is KBL13^T (=JCM 14209^T =DSM 18933^T).