Production, purification and characterization of reutericin 6, a bacteriocin with lytic activity produced by Lactobacillus reuteri LA6

A bacteriocin (Reutericin 6) produced by Lactobacillus reuteri LA6, was purified by hydrophobic chromatography from the modified MRS broth (D′-MRS) with 6180-fold increase in specific activity with 14% recovery. The molecular weight of reutericin 6 was determined to be 2.7 kDa by SDS-PAGE and ESI-MS. By amino acid analysis, reutericin 6 comprised of 67% hydrophobic and polar neutral amino acids. Lanthionine was not detected. The lytic activity against Lactobacillus delbrueckii subsp. bulgaricus JCM 1002T and NIAI B6 was detected by the decrease of both turbidity and the number of viable cells, and by leaking of β-galactosidase.