果胶酶生产菌株的筛选、发酵优化及其酶学性质研究

Screening,Fermentation Optimization and Enzymatic Properties of Pectinase-Producing Strains

果胶酶是一种降解果胶的复合酶,广泛应用于果汁加工及其他工业领域。但目前在工业应用中果胶酶的比活力相对较低,工业应用受限。文章从自然界筛选出一株比活力较高的野生型菌株黑曲霉Aspergillus sp.CM3,优化后最佳产酶条件为麸皮10 g/L、氯化铵0.2 g/L、氯化钙0.08 mol/L、初始pH3.0、发酵温度为28℃、接种量4%、装液量40 mL/250 mL,将果胶酶酶活从2115.4 U/mL提高到了3942.7 U/mL;并对果胶酶进行了分离纯化,纯化后的果胶酶蛋白分子质量约为38.34 ku,纯化倍数为3.26倍,比酶活提高至174319.6 U/mg,回收率为0.86%;最后探究了该果胶酶的酶学性质,该果胶酶的最适反应温度为50℃,最适pH值为4.0,其中Ca^(2+)对果胶酶酶活起到了促进作用。纯化后果胶酶用于果汁出汁率实验,2种水果的出汁率均提高了12%左右,这表明纯化后的果胶酶可用于果汁出汁。

Pectinase is a complex enzyme that degrades pectin and is widely used in fruit juice processing and many other industrial fields.However,the specific activity of pectinase in industrial application is still relatively low,and industrial applications are limited.The articles screens out a wild strain Aspergillus sp.CM3 from nature,the optimal fermatation process condition are:bran 10 g/L,ammonium chioride 0.2 g/L,calcium chloride 0.08 mol/L,inital pH value 0.3,fermentation temperature 28℃,inoculum volume 4%,liquid volume 40 mL/250 mL.The pectinase activity was increased from 2115.4 U/mL to 3942.7 U/mL.The pectase was isolated and purified pectinase was about 38.34 ku,the purification multiple was 3.26 times,the specific activity of 174319.6 U/mg and the recovery rate was 0.86%.Finally,the enzymatic properties of the pectase were explored,and the optimum reaction temperature of the pactase wase 50℃and the optimum pH was 4.0,Ca^(2+) played a role in promoting the pectinase activity.Purified peotinase was used in juice,both two juice yield were increased by about 12%,indicating that the purified pectinase can be used for juice clarificatin.