食品与发酵工业2023，Vol.49Issue(23)：50-55,6.DOI:10.13995/j.cnki.11-1802/ts.034506
马克斯克鲁维酵母β-半乳糖苷酶合成条件的优化及其酶学性质表征
Optimization of conditions for production of Kluyveromyces marxianus β-galactosidase and characterization of its enzymatic properties
摘要
Abstract
β-Galactosidase is a widely used food additive,primarily used to degrade lactose in dairy products and alleviate symptoms of lactose intolerance.In this study,we optimized the fermentation conditions of Kluyveromyces marxianus,a strain preserved in our labo-ratory.Under the conditions of 20 g/L galactose,20 g/L corn steep powder,40 ℃,initial pH 6.5,and 150 r/min,the crude enzyme displayed an enzyme activity of 26.3 U/mL,indicating that the strain had the potential to efficiently produce β-galactosidase using cheap carbon and nitrogen sources.Further purification via DEAE anion exchange chromatography resulted in a purified enzyme with a specific activity of 124.09 U/mg.The purified enzyme exhibited an optimal temperature of 40 ℃,an optimal pH of 6,a Michaelis constant of 5.28 mmol/L,and a catalytic constant of 4.74 s-1.Additionally,the enzyme was found to be promoted by Mg2+and exhibited excellent thermal stability between 20-40 ℃,retaining 95.6％activity at 40 ℃ for 30 min.As K.marxianus,which belongs to the same edible strain as Kluyveromyces lactis,its β-galactosidase has better thermal stability than common K.lactis,and has potential industrial applica-tion potential.关键词
马克斯克鲁维酵母/β-半乳糖苷酶/可食用菌株/耐热酶/产量优化Key words
Kluyveromyces marxianus/β-galactosidase/edible strains/thermostable enzymes/yield optimization引用本文复制引用
刘娇娇,孟金浩,梁权耀,曾婷靖,左恩辉,庞宗文,李树波..马克斯克鲁维酵母β-半乳糖苷酶合成条件的优化及其酶学性质表征[J].食品与发酵工业,2023,49(23):50-55,6.基金项目
国家自然科学基金项目(31760253,32160558) （31760253,32160558）
