Effects of fermentation conditions on cholesterol degradability

In order to improve the ability of cholesterol degradation and the number of viable bacteria, the study optimized the fermentation conditions of mixed strains, aiming at obtaining high efficient cholesterol-degrading strains and providing the basis for the application of lactic acid bacteria. Four strains of lactic acid bacteria with auxiliary cholesterol-lowering activity were selected and mixed with 1∶1∶1∶1 mixture. The single factor experiment and response surface analysis were used to study the effects of cholesterol degradation rate and viable count.Conditions were optimized.The optimum fermentation conditions were as follows: lactose 24.19 g/L, tryptone 8.41 g/L, culture temperature 28.28 ℃, culture time 30 h, inoculation amount 5.24%.After optimization, the degradation rate of cholesterol in the mixed strains increased from 39.56% to 53.43%, increased by 35.06%.The totol colonies was increased from 8.87 lg CFU/m L to 9.63 lg CFU/m L. The viable count was an order of magnitude higher than that before optimization.