摘要
从库特氏杆菌发酵液中分离出可降解β-类胡萝卜素的酶,经初步纯化,研究其生化性质,为后续研究纯酶性质和应用打基础。以β-胡萝卜素标准品为底物,通过检测其反应最适温度、耐热性、反应最适pH、耐酸性、活化能、米氏常数,最大反应速率等研究该类胡萝卜素降解酶的生化性质。试验结果表明:80℃为最适反应温度,具有较稳定的耐热性。该酶的耐酸性较强,在pH=3.0时活性最高。Fe^(2+)、Mn^(2+),Zn^(2+)抑制酶的活性,Al^(3+)、Fe^(3+),Mg^(2+),Ca^(2+)促进酶活性。由阿伦尼乌斯方程得酶反应的活化能Ea为230.3KJ/mol。在70℃和p H 3.0的条件下,其反应动力学常数Km为4.13 mmol/L,最大反应速率Vmax为1.1842umol/(L·min)。
The chemical properties of a purified putative enzyme of Kurthia from fermentation broth with carotenoid cleavage activity was studied.Method：The properties of putative carotenoid degrading enzyme cleaved β-carotene were studied at different conditions,such as optimum temperature,thermostability,optimal p H,acid resistance and Ea.Results：The optimum temperature of the active peptide was 80 ℃ and the enzyme was relatively thermostable.The activation energy（Ea） calculated using Arrhenius plot between 30 and 60℃ was 230.3 KJ/mol.The enzyme was found to be more acid resistant,showing higher activity at p H 3.0.Fe^2＋,Mn^2＋,Zn^2＋ was the inhibitor of enzyme while Al^3＋,Fe^3＋,Mg^2＋,Ca^2＋ were the promoter of the enzyme.The putative enzyme cleaved β-carotene with a Km value of 4.13 mmol/L and VMax value of 1.1842μmol/（L · min） at p H 3.0 and 70 ℃.
出处
《中国食品添加剂》
北大核心
2017年第4期59-66,共8页
China Food Additives
基金
国家自然科学基金项目(31360402):枸杞酒发酵体系中类胡萝卜素降解规律及产香机理研究
