植物乳杆菌发酵生产苯乳酸的条件优化研究

Optimization of Lactobacillus plantarum fermentation conditions in producing phenyllactic acid

苯乳酸(Phenyllactic Acid,PLA)能够抑制多种腐败菌与致病菌,具有抑菌谱宽、稳定性高、溶解性好等优点,是一种新型天然抑菌物质。以苯丙氨酸为底物,利用传统微生物发酵方法生产苯乳酸,并通过单因素试验、正交试验优化了发酵温度、pH、接种量和底物。结果表明,植物乳杆菌Lactobacillus plantarum AB-1发酵苯乳酸的产量随着发酵时间增加而增加,在24 h达到最大值,然后趋于稳定。植物乳杆菌Lactobacillus plantarum AB-1发酵生产苯乳酸的最佳条件为:发酵时间48 h、发酵温度37℃、初始pH6.4、初始接种量2%、苯丙氨酸添加量3.470 g/L,优化后苯乳酸的产量为(252.44±2.63)mg/L,与优化前(115.99±4.25)mg/L相比,产量提高了1.17倍。

Phenyllactic acid（PLA） has antimicrobial activity against many kinds of food pathogenic and spoiled bacteria. PLA is a new natural antibacterial substance with wide antimicrobial spectrum, high stability and good solubility. This study used the traditional microbial fermentation method to produce phenyllactic acid from the phenylalanine. The optimal temperature, pH, inoculation and phenylalanine concentration of the Lactobacillus plantarum AB-1 fermentation was also investigated. The results indicated that PLA concentration increased with the increase of fermentation time, and reached the maximum concentration after 24 h fermentation. The optimal fermentation conditions of Lactobacillus plantarum AB-1 in producing phenyllactic acid were as follows： fermentation time 48 h, fermentation temperature 37 ℃, initial pH 6.4, initial inoculum concentration 2%, phenylalanine concentration 3.470 g/L. Under the optimal conditions, the phenyllactic acid production is（252.44±2.63）mg/L, which increased by 1.17 fold compared with the yield of（115.99±4.25）mg/L before optimization.