乳酸菌摇瓶增殖培养工艺研究

采用自行筛选的适用于作为高效冻干酸奶发酵剂的嗜热链球菌S.t-SY和保加利亚乳杆菌L.b-DR为出发菌株,在优化的麦芽复合汁增菌培养基上进行摇瓶增殖培养。通过研究培养温度、培养方式、基质起始pH值、接种量、中间补料方式等因素对乳酸菌摇瓶增殖培养的影响,优化乳酸菌摇瓶增殖培养的工艺条件。试验结果表明:在麦芽复合汁增菌培养基中乳酸菌增殖培养的最适条件是:培养温度37℃,基质起始pH值6.5～7.5,接种量0.2%～0.3%,静置培养16h,收获期S.t-SY和L.b-DR活菌数分别达到2.93×109、2.74×109cfu/mL。本试验结果为乳酸菌进一步应用麦芽复合汁增菌培养基生产高效浓缩直投式发酵剂提供了技术参数。

Research of Shake Flask Proliferation Cultivation Technology of Lactobacillus

In this test,we use Streptococcus thermophilus S.t-SY and Lactobacillus bulgaricus L.b-DR as the starter culture,which were screened by ourselves and suitable to be high-activity concentrated Yoghourt freeze-dry starter culture,and then cultivated in optimal wort culture medium to do the shake-flask culture.The effect of cultivation temperature,mode,initial pH of culture medium,inoculation amount,feed culture on the cell growth of Lactobacillus was studied at the level of 300 mL flask.The optimum condition to cultive S.t-SY and L.b-DR was that the initial pH of medium was 6.5～7.5,inoculation 0.2%～0.3%,cultivated 37 ℃ for 16h.In the condition,the living-cell number of S.t-SY and L.b-DR was 2.93×109,2.74×109 cfu/mL.This test provides technical parameters for further application of wort culture medium expansion of Lactobacillus cultivation to be high-activity concentrated Yoghourt freeze-dry starter culture.