Purification and characterization of bacteriocin produced by Lactobacillus rhamnosus zrx01

The bacteriocin-zrx01 produced by Lactobacillus rhamnosus zrx01 was purified, its basic biochemical characteristics and bacterial antibacterial sensitivity were studied. The bacteriocin-zrx01 was separated and purified using ethyl acetate, AKTA purifier™ 10 protein purifier with HiTrap™ Capto™ Q anion exchange chromatography and Superdex™ 75 10/300 GL gel chromatography. The purity of bacteriocin-zrx01 was analyzed using high performance liquid chromatography . The sensitivity to temperature, pH and enzymes of the purified bacteriocin-zrx01 was measured as the diameter of the antimicrobial ring. The results showed that the purified bacteriocin-zrx01 bacterial antibacterial activity was good, and the specific vitality was raised from the original fermentation broth at 625 to 5330 AU/mg. The bacteriocin-zrx01 had a higher stability at pH 3–9, and the antibacterial activity was the strongest at pH 4. When pH was 9, it still retained 86% of the antibacterial activity of the control group. Bacteriocin-zrx01 was cold-stable at −70 and −20 °C for 30 min. It still retained 57% antimicrobial activity compared with the control after being autoclaved at 121 °C for 30 min. Some enzymes, such as protease K, neutral protease, trypsin, thrombin, alkaline protease and papain , affected its antibacterial activity, but it was sensitive to pepsin , and the diameter of the antimicrobial ring decreased by 50% after 2 h of pepsin treatment. These results showed that the bacteriocin-zrx01 produced by Lactobacillus rhamnosus zrx01 might have a potential as a natural food preservative , although in vivo studies are needed.