Lactococcus garvieae subsp bovis subsp nov., lactic acid bacteria isolated from wild gaur (Bos gaurus) dung, and description of Lactococcus garvieae subsp garvieae subsp nov.

A taxonomic investigation was performed on a Gram-stain-positive coccus, designated strain BSN307(T), isolated from gaur (Indian bison, Bos gaurus) dung based on phenotypic and molecular approaches. Based on the biochemical tests, cellular morphology and 16S rRNA gene sequence similarity, this strain was found to be a member of the genus Lactococcus and closely related to Lactococcus garvieae ATCC 49156(T) (99.6% 16S rRNA gene sequence similarity) and L. actococcus formosensis 516(T) (99.0 %). However, DNA-DNA hybridization studies showed that the level of relatedness between strain BSN307(T) and L. garvieae ATCC 49156(T) was 75.8 %, suggesting that it represented a novel subspecies of L. garvieae. The inability to grow in brain heart infusion (BHI) medium at pH 9.6, in tryptic soy agar (TSA) with 4% (w/v) NaCl and at 42 degrees C (MRS agar) clearly differentiated BSN307(T) from L. garvieae ATCC 49156(T). Rep-PCR fingerprint patterns, substantial differences in summed feature 8 (C-18 : 1 omega 7c/C-18 : 1 omega 6c), C-19 : 0 cyclo omega 8c and C-16 : 0 also differentiated strain BSN307(T) from the reference strain of L. garvieae. Moreover, analysis of the housekeeping genes pheS and rpoA revealed sequence similarities that were at the limit for species differentiation (92.2 and 97.8 %, respectively). Combined genotypic and phenotypic data indicate that strain BSN307(T) represents a subspecies of L. garvieae for which the name Lactococcus garvieae subsp. bovis subsp. nov. is proposed. The type strain is BSN307(T) (=DSM 100577(T) =MCC 2824(T) =KCTC 21083(T)).