STUDY ON ANTIBACTERIAL CHARACTERIZATION FOR STRAIN FROM LACTID ACID BACTERIAWH12-2-1 PRODUCING BACTERIOCIN IN TRADITIONAL DAIRY PRODUCTS

Antibacterial biochemical characterization of a bacteriocin produced L.pentosus WH12-2-1 isolated from traditional dairy products was studied by the method of Oxford cup.The experimental results revealed that the most suitable fermenting conditions for WH12-2-1 producing bacteriocin were:culturing 48 h in MRS at 30 ℃,and Tween80 and other antibacterial substances can promote producing of bacteriocin .The biological features of bacteriocin showed that its optimum pH was 2.0. The bacteriocin produced by WH12-2-1 was steady in acid or weak acid conditons and still active after boiled in 121 ℃ for15 min,so the bacteriocin had good thermal stability. The bacteriocin was sensitive to trypsin and chymosin but insensitive to pepsin and papain,and can inhibited bacteria from growing rather than killing it. The inhibition spectrum of Bacteriocin is very wide, it can inhibit both putrefying bacteria and pathogenic bacteria very well.So it has good potentiality of development and application.