高产大豆异黄酮糖苷转化酶乳酸菌的筛选及其发酵条件的优化

Isolation and identification of high-yield soy isoflavone glycosidase of lactic acid bacteria and optimization of fermentation conditions

采用高效液相色谱法测定发酵豆乳中游离型大豆异黄酮含量,以此为指标,从传统发酵食品分离筛选的100株乳酸菌中,选出一株发酵后游离型大豆异黄酮产量最高的作为生产功能性发酵豆乳的发酵菌株。经生理生化及遗传学特性鉴定该菌株为植物乳杆菌。并通过单因素和响应面优化实验对影响游离型大豆异黄酮产量的3个发酵因素,即发酵时间、发酵温度、接种量,进行优化,得出最佳发酵条件为:发酵温度45℃、发酵时间17h、接种量5%,在此条件下游离型异黄酮的产量为132.814μg/mL。

For production of functional fermented soymilk,one strain was selected from one hundred lactic acid bacteria isolates based on their capacities to hydrolyze isoflavone glucosides to aglycones by high performance liquid chromatography（HPLC）. Based on the biochemistry and genetic characteristics analysis,the strain was classified as Lactobacillus plantarum. Fermentation conditions including fermentation time,temperature and inoculum amount were optimized by one-factor-at-a-time and response surface methodology（RSM）. The optimum fermentation condition as follows ：fermentation for 17h at 45℃ with inoculation amount of 5% ,while the soy isoflavone aglycones production was 132.814μg/mL.