果胶酶液体发酵条件优化与酶学特性研究

摘要

本文通过液体摇瓶发酵，采用DNS法测定酶活性，研究不同条件对果胶酶活性的影响以及果胶酶的酶学特性。结果表明对于HS021号菌，适宜的发酵条件为初始发酵液pH 6.0，菌龄和发酵时间24 h，加入0.05% Na+，果胶酶活性可达17.67 U/mL，最适温度为50℃，最适pH 5.0。对于HS047号菌，适宜的发酵条件为初始发酵液pH 6.0，菌龄和发酵时间24 h，果胶酶活性可达15.66 U/mL，最适温度为45℃，最适pH 5.0。对于HS053号菌，适宜的发酵条件为初始发酵液pH 6.0，菌龄24 h，发酵时间48 h，加入0.05%的Na+，果胶酶活性可达11.32 U/mL，最适温度为55℃，最适pH5.0。对于HS053号菌木粉发酵液可以替代果胶底物发酵液。紫外诱导后，酶活均下降。%Pectinase is widely used in industrial production, mainly by microbial fermentation. The pectinase was produced via flask culture and its activity was determined by DNS. The effect of different conditions of pectinase activity and enzymatic properties of pectinase was studied. The results showed that for HS021 bacteria, the optimum fermentation conditions were initial pH6.0, bacteria age and fermentation time 24 h, added 0.05% Na+, pectinase activity reached 17.67 U/mL, the optimum temperature 50℃, the optimum pH 5.0. For HS047 bacteria, the optimum fermentation conditions were initial pH6.0, bacteria age and fermentation time 24 h, pectinase activity reached 15.66 U/mL, the optimum temperature 45℃, the optimum pH 5.0. For HS053 bacteria, the optimum fermentation conditions were initial pH6.0, bacteria age 24 h, fermentation time 48 h, added 0.05% Na+, pectinase activity reached 11.32 U/mL, the optimal temperature 55℃, the optimum pH 5.0. For HS053 bacteria broth flour could replace pectin substrate fermentation broth. After UV induction, enzyme activity decreased.