结合淀粉活性乳酸菌利用生淀粉产酶条件及代谢产物  

Optimization of Culture Conditions for Production of Raw Starch-Degrading Amylase by Lactobacillus paracasei L1 and Analysis of Its Metabolites

作　　者：郭浩男 张莉力 冯琳琳 王天琪 王成 赵昕琪 许云贺 GUO Haonan;ZHANG Lili;FENG Linlin;WANG Tianqi;WANG Cheng;ZHAO Xinqi;XU Yunhe(College of Food Science and Engineering,Jinzhou Medical University,Jinzhou 121001,China)

机构地区：[1]锦州医科大学食品科学与工程学院,辽宁锦州121001

出　　处：《食品科学》2020年第24期46-53,共8页Food Science

基　　金：国家自然科学基金面上项目(31301499);辽宁省自然科学基金项目(2019-ZD-0600,2018022052);辽宁省重点研发计划项目(2018225027)。

摘　　要：为研究具有特异性结合淀粉活性乳酸菌的淀粉代谢能力,以副干酪乳杆菌L1为对象,研究其产酶性质及对生淀粉的利用能力,对产酶条件进行优化,利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳测定生淀粉酶分子质量,高效液相色谱法测定碳水化合物和有机酸的产生及利用情况。结果表明,生淀粉酶存在于L1菌体细胞表面和上清液中,该酶对不同来源生淀粉均具有一定的水解能力,生淀粉对该酶具有诱导作用。在培养基初始pH 6.5、淀粉占碳源比例68%、碳源添加量2.03%条件下,表现出最高酶活力为(191.64±0.63)U/mL。碳水化合物水解产物麦芽低聚糖为中间产物,葡萄糖、麦芽糖为终产物;有机酸水解产物以乳酸为主要产物,柠檬酸为次级产物。本研究从代谢角度证实了L1结合生淀粉的同时,具有利用生淀粉的能力,对乳酸菌在淀粉类基质中的应用有着重要意义。In order to study the starch-metabolizing ability of lactic acid bacteria with specific starch-binding activity,Lactobacillus paracasei L1 was evaluated for its ability to produce raw starch-degrading amylase by utilizing raw starch.The conditions for enzyme production were optimized and the molecular mass of the amylase was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE).The production and utilization of carbohydrates and organic acids were determined by high performance liquid chromatography(HPLC).The results showed that raw starchdegrading amylase existed on the cell surface and in the culture supernatant of L1.The enzyme could hydrolyze raw starch from different sources to a certain extent,and raw starch could induce the production of the enzyme.The highest enzyme activity of(191.64±0.63)U/mL was achieved under the following conditions:initial medium pH 6.5,68%starch in total carbon source,and 2.03%carbon source.Glucose and maltose were the final products of carbohydrate hydrolysis,and malt oligosaccharide was the intermediate product.Lactic acid was the main product of organic acid hydrolysis while citric acid was the secondary product.This study proved that L1 can combine and utilize raw starch,which is of great significance to the application of lactic acid bacteria in starch matrices.

关 键 词：副干酪乳杆菌L1 生淀粉酶 产酶优化 代谢产物 

分 类 号：TS231[轻工技术与工程—粮食、油脂及植物蛋白工程]