ABSTRACT
The genus Lactococcus comprises 13 species: Lactococcus lactis, L. taiwanensis, L. hirilactis, L. fujiensis, L. nasutitermitis, L. garvieae, L. petauri, L. formosensis, L. piscium, L. raffinolactis, L. reticulitermitis, L. chungangensis, L. plantarum, and L. laudensis. The phenotypic differences between cremoris and lactis subspecies are the salt tolerance and ability to hydrolyze arginine, both typical for subsp. lactis but absent in cremoris. Bacteriocins are bacterial proteins or peptides that inhibit the growth of other bacterial strains or species. The pathogenicity and diagnostics of L. garvieae has been a special focus of attention since the species can also be found in clinical specimen of warm-blooded animals and is frequently found as an accidental commensal microorganism in food products. Species identification is based on physiological, chemotaxonomic, and molecular biological criteria. L. lactis, the species most commonly found in raw milk, is thought to arise as a contamination from forage.
