乳酸脱氢酶高产菌株的选育及条件研究

Breeding of High Lactate Dehydrogenase (LDH) Producing Strains and Optimization of the Fermentation Conditions

以植物乳酸短杆菌RS2-2(Lactobacillus plantarum)为出发菌株,经紫外线、亚硝基胍单独处理和复合处理,获得1株乳酸脱氢酶高产菌株U-N-B14,通过优化实验对该菌株生产乳酸脱氢酶的营养要求和发酵条件进行了研究,优化后的发酵培养基组成为(g/L):酵母膏10,麦芽糖12,乙酸铵4,K2HPO44,NaCl 8,吐温80 2mL/L。发酵条件是:培养温度30℃,pH值6.5,培养时间24 h,接种量8%。在此条件下,1.5 m3罐中试生产的乳酸脱氢酶产量可达1 497 U/g。

A high lactate dehydrogenase （LDH） producing mutant U-N-B14 was screened from Lactobacillus plantarurn RS2-2 by UV and NTG treatment. The optimum medium and fermentation conditions were optimized by single factor experiments. The optimum medium were（g/L） ： yeast extract 10, maltose 12, NH4AC 4, K2HPO4 4,NaCl 8,Tween 80 2 mL/Lo The optimum conditions were as follows：reaction temperature 30℃ , pH 6.5 ,incubation time 24h, inoculum 8 %. The LDH production level in 1.5 m^3 fermentation reactor reached 1 497 U/mg under the optimum conditions.