嗜酸乳杆菌P302菌株产类细菌素最佳条件的研究

目的对产类细菌素嗜酸乳杆菌P302的发酵条件进行研究。方法采用琼脂扩散法测定发酵上清液对大肠埃希菌O139的抑菌活性。结果通过正交试验确定P302产类细菌素的最佳培养基组分为牛肉膏4％、胰蛋白胨0．2％、酵母粉0．8％、碳酸钙0．4％和蔗糖1％，0．4％复合维生素，0．3％Tween-80有利于类细菌素的产生。发酵工艺条件为最适初始pH7．0，最适温度37℃，最佳接种量0．3％，种龄14h，厌氧培养22h。结论通过优化发酵条件和发酵工艺，类细菌素的产量提高了35％。

Study on the best bacteriocin-like production condition of Lactobacillus acidophilus P302

Objective To investigate the fermentation conditions for growth and antibacterial substance production by Lactobacillus acidophilus P302. Method The antibacterial activity of the supernatant against Escherichia coli O139 was tested with agar diffusion. Results The optimum fermentation conditions for P302 to produce bacteriocin-like included the following：beef extract 4%, peptone 0.2%, yeast extract 0.8%, calcium carbonate 0.4%, sucrose 1%, vitamin complex 0.4% and Tween-80 0.3%. This formula of modified MRS could stimulate the generation of bacteriocin-like. The optimum initial pH was 7.0,while the best temperature was 57 ℃, with the inoculation amount of 3% （v/v） ,the seed age of 14 h, and the fermentation period of 22 h. Conclusion Under the above conditions, the production of bacteriocin-like was increased by 35%.