啤酒中乳酸细菌分离用培养基的优化

Optimization of the medium for isolation of lactic acid bacteria in beer

根据乳酸细菌的营养要求,优化了培养基(B-MRS)的成分及用量,确立了B-MRS培养基的配方。通过测定乳酸细菌在B-MRS培养基和MRS培养基中的生长曲线,确定乳酸细菌在B-MRS培养基中的培养终止时间为24h,比MRS培养基提前约10h,且吸光度值OD_(450)达到0．45,酸度达到6．50°T。

According to the nutritional requirement of lactic acid bacteria, B-MRS medium based on MRS medium was optimized which was used to isolate lactic acid bacterias in beer. The composition and dosage in B-MRS medium were as follows： glucose3%, tryptone 1%, soya peptone 1.5%, K2HPO4 0.4%, MgSO4·7H2O 0.06%, yeast extract 0.5%, tomato juice 5%, pH 6.5. The growth curves of lactic acid bacteria in B-MRS and MRS were determined. The cultivation time in B-MRS was 24 h and 10 h shorter than in MRS. The absorbance （OD450）of the culture medium was 0.45 and acidity got to 6.50°T.