Separation and purification of Lactobacillus XH2 bacteriocin produced by Lactobacillus acidophilus

Lactobacillin XH2 bacteriocin produced by Lactobacillus acidophilus was extracted by two methods,chloroform extraction and ammonium sulfate salting-out.The bacteriostatic diameter of the chloroform extract was17.40 mm,and that of the precipitate,obtained from ammonium sulfate salting- out,was 15.50 mm.By comparison,the antibacterial effect with 60% ~80% saturation gradient was significant.After purified by cellufine A-500 anionexchange,the bacteriostasis potency and specific activity of the two crude extracts were significantly increased to380.60 Au /mL and 355.60 Au /mL,5.55 Au /μg and 9.96 Au /μg,which purification factors were 15.86 and 28.46 respectively.Tricine-SDS-PAGE showed that its molecular weight was between 14.4~20.1ku.