Lacticin, a bacteriocin produced by Lactobacillus delbrueckii subsp. lactis

Twenty‐one strains of Lactobacillus delbrueckii and L. helveticus were tested for bacteriocin production against each other. Lactobacillus delbrueckii subsp. lactis JCM 1106 and 1107 produced an inhibitory agent active against L. delbrueckii subsp. bulgaricus JCM 1002 and NIAI yB‐62, L. delbrueckii subsp. lactis JCM 1248 and L. delbrueckii subsp. delbrueckii JCM 1012. Lactobacillus delbrueckii subsp. lactis JCM 1248 inhibited only the growth of L. delbrueckii subsp. bulgaricus NIAI yB‐62. These agents were sensitive to proteolytic enzymes and heating (at 60°C for 10min). These agents were considered to be bacteriocins and designated lacticin A and B.