植物乳杆菌生物合成苯乳酸条件优化研究

Optimization of bioconversion conditions for phenyllactic acid production by Lactobacillus plantarum

以苯丙酮酸为底物,以植物乳杆菌静息细胞为催化剂,对苯乳酸生物合成条件进行了优化。试验首先确定了不同因素对苯乳酸产量的影响,然后通过正交试验优化了最佳合成条件。结果表明,细胞培养时间为18h时催化活性最高,且在温度为35℃,pH为6.5,静息细胞、苯丙酮酸和葡萄糖质量浓度分别为80g/L、3.0g/L和4.0g/L的催化条件下,经过4h转化,苯乳酸产量达到最高,为1.68g/L。在最优条件下,静息细胞重复利用4次,苯乳酸产量没有显著降低,表现出了植物乳杆菌转化苯丙酮酸合成苯乳酸的良好稳定性。

Phenyllactic acid(PLA)was produced from phenylpyruvic acid(PPA)as substrate with resting cells of Lactobacillus plantarum as catalyst.Firstly,the factors influencing PLA yield were investigated by single factor tests,and then the bioconversion conditions were optimized by orthogonal experiments.The results indicated that the cells had the highest catalytic activity after culturing for 18 h,and the optimum conditions for PLA production were as follows:temperature 35℃,pH 6.5,and the concentrations of resting cells,PPA and glucose were 80 g/L,3.0 g/L and 4.0 g/L,respectively,and the PLA yield was the highest of 1.68 g/L after conversion for 4 h.Under these optimized conditions,after four recycles of resting cells,the PLA yield was not reduced significantly,indicating a good stability in the conversion of PPA to PLA by L.plantarum.