Lactococcus hircilactis sp. nov. and Lactococcus laudensis sp. nov., isolated from milk

Abstract

Two strains of lactic acid bacteria, designated 117T and 4195T, were isolated from goat milk in Valtellina, Italy and from cow milk in Valle Trompia, Italy, respectively, and characterized taxonomically by a polyphasic approach. The strains were Gram-stain-positive, coccoid, non-spore-forming and catalase-negative bacteria. Morphological, physiological and phylogenetic data indicated that these isolates belonged to the genus Lactococcus. Strain 117T was closely related to Lactococcus fujiensis, Lactococcus lactis subsp. lactis, L. lactis subsp. cremoris, L. lactis subsp. hordniae, L. lactis subsp. tructae and Lactococcus taiwanensis, showing 93–94 % and 82–89 % 16S rRNA and rpoB gene sequence similarities, respectively. Strain 4195T was closely related to Lactococcus chungangensis, Lactococcus raffinolactis, Lactococcus plantarum and Lactococcus piscium, showing 92–98  % and 86–99  % 16S rRNA and rpoB gene sequence similarities, respectively. Based on this evidence and the data obtained in the present study, the milk isolates represent two novel species of the genus Lactococcus, for which the names Lactococcus hircilactis sp. nov., and Lactococcus laudensis sp. nov. are proposed. The respective type strains are 117T ( = LMG 28352T = DSM 28960T) and 4195T ( = LMG 28353T = DSM 28961T).