Optimization of enrichment medium of Qula compound lactic acid bacteria

In order to improve viable Qula special compound lactic acid bacteria in the fermentation liquid,the single factor experiment of nitrogen sources,carbon sources and growth factors,response surface methodology were used to optimize the composition of enrichment medium. There were no antagonistic effects among MGD1- 3,MGB39- 5 and BM5152,so they can mix cultures. And it indicated that MRS medium was the most suitable for compound lactic acid bacterias growth.Box- Behnken test and response surface were analyzed to determine the optimum adding amount,and its optimal composition was carbon source 18.11 g / L,nitrogen source 26.72 g / L,Tween-80 1.88 g / L and VB61.41 g / L.The OD600 of strains cultured in the optimized MRS medium reached 2.173,the cell concentration in the optimized MRS medium reached 4.01 × 1010 CFU / m L,which was 8.29 times higher than observed in the initial medium.