Optimization of medium and culture conditions of bacteriocins by Lactobacillus acidophilus

In order to increase the counts of Lactobacillus acidophilus and the yield of bacteriocins,medium and culture conditions was optimized by single factor and orthogonal test.The optimum medium were as follows: glucose 10g/L,peptone 15g/L,beef extract 15g/L,NaCl 3g/L,CaCO3 1g/L,MgSO4·7H2O 0.4g/L,C6H17N3O7 2g/L,K2HPO4·3H2O 4g/L,MnSO4·H2O 0.2g/L.The optimum culture conditions were as follows: culture temperature 37℃,culture time 22h,inoculum 2%,pH value 6.8 and shaking flasks speed 160r/min.The titre of bacteriocins reached 231.34 AU/ml under the conditions.