Optimization of Enrichment Medium for Bifidobacterium adolescentis by Response Surface Methodology

Abstract:

Response surface methodology was used to optimize the fermentation medium based on the medium MRS to increase the viable bacteria count of B. adolescentis. Meanwhile，the growth curve and pH were compared before and after optimization. According to the results of response surface analysis，the enrichment medium components were determined as follows：glucose 15.85 g/L，fructo-oligosaccharide 15.85 g/L，peptone 14.45 g/L，beef extract 8.67 g/L，yeast extract power 5.78 g/L，ammonium citrate 2.75 g/L，K2HPO4·3H2O 2.75 g/L，sodium acetate 6.875 g/L，Tween-80 1.0 mL，MgSO4·7H2O 0.2 g/L，MnSO4·H2O 0.05 g/L，L-cystein-HCl 0.5 g/L. Cultivated in optimized enrichment medium，B.adolescentis reached stationary phase at about 28 h，which was shorter 12 h than before； the viable counts reached up to 8.9×109 CFU/mL，which was 1.73 times as many as before.