Characterization of bacteriocin HV219, produced by Lactococcus lactis subsp. lactis HV219 isolated from human vaginal secretions

Bacteriocin HV219, produced by Lactococcus lactis subsp. lactis HV219, is active against Gram-positive and Gram-negative bacteria. Activity was lost when treated with proteolytic enzymes, SDS, Triton X-114 and Triton X-100, but not at pH 2.0 to 10.0 or after 20 min at 121 degrees C. Growth in the presence of yeast extract as sole nitrogen source yielded 3200 AU/ml. No bacHV219 activity was recorded in MRS broth with maltose, mannose, lactose or sucrose as sole carbohydrate, but fructose yielded 1600 AU/ml. K(2)HPO(4) at 10.0 g/l yielded 3200 AU/ml. Addition of 1.0 mg/l cyanocobalamin, l-ascorbic acid and thiamine to MRS broth yielded 3200 AU/ml, 1600 AU/ml and 1600 AU/ml, respectively. The mode of activity is bacteriolytic, as confirmed by atomic force microscopy.