粘膜乳杆菌发酵乳清生产L-乳酸的研究

Production of L-lactic Acid by Lactobacillus mucosae L-05 on Whey

粘膜乳杆菌L-05是从猪小肠中分离的兼性厌氧革兰氏阳性细菌,是乳杆菌属中发现的新种。本文研究了粘膜乳杆菌L-05利用乳清粉生产L-乳酸的摇瓶发酵特性,并对其发酵动力学进行了初步探讨。研究结果表明,粘膜乳杆菌生长并合成L-乳酸的适宜条件为37℃,起始pH6.0,摇床转速为150r/min。在优化发酵培养基(g/L)乳清30,蛋白胨15,酵母提取物2,柠檬酸氢二铵2,CH3COONa2.5,K2HPO42,MgSO4·7H2O1.16,MnSO4·4H2O0.5中对乳清的转化率为88.1%,并对最适生长条件下的细胞生长模型和L-乳酸合成模型进行了拟合。

Lactobacillus mucosae L-05, a new strain was isolated from pig intestine, belonging to G^＋ facultative anaerobes. The fermentation characteristics of Lactobacillus mucosae L-05 on whey were studied. The high conversion rate of whey to L-lactic acid occurred when the strain was cultured in the optimum conditions （pH6.0） whey 30 g/L, peptone 15 g/L, yeast extract 2 g/L, diammonium citrate 2 g/L, CH3COONa 2.5 g/L, K2HPO4 2 g/L, MgSO4 · 7H2O 1.16 g/L, MnSO4 · 4H2O 0.5 g/L under 37℃ and 150 r/min, with conversion rate 88.1%. The mathematical kinetic models describing the course of cell growth and L-lactic acid fermentation have been established.