产壳聚糖酶菌株发酵条件的优化及酶解条件的研究

Optimization of chitosanase strain producing enzyme conditions and study on its degradation chitosan

通过正交实验,对从土样中分离得到的1株产壳聚糖酶菌株的产酶条件进行了优化。确定其最适产酶发酵条件是:起始pH6.2,接种量2%,32℃,培养78 h。在最适产酶条件下,该菌株发酵液中壳聚糖酶活力可达到2.16 U/mL。同时,对壳聚糖酶降解壳聚糖生成壳寡糖的条件进行了研究,结果表明:该菌株生产的壳聚糖酶的最适作用温度、pH和底物浓度分别为42℃、5.2和1.5%(w/v),Mn2+对该酶酶活具有明显的促进作用,Fe2+和Cu2+对壳聚糖酶活力具有明显的抑制作用。最后对酶解产物进行了HPLC分析。

By the orthogonal experiment,the optimal condition of strain screening from soil sample for the production of chitosanase was determined： the initial pH6.2,inoculum 2%,32 ℃,and shaking cultivation for 78 h.Under the optimal cultivition conditions,The chitosanase activity of fermented broth could reach 2.16 U/mL.And study the conditions of enzymatic hydrolysis process for preparing chitooligosaccharides,the results demonstrate the optimum temperature and pH for degrading chitosan was 42 ℃,5.2 and 1.5%（w/v）,respectively.Mn2＋ had obvious activation to the enzyme activity,while Fe2＋ and Cu2＋ inhibited the enzyme activity strongly.Finally,the enzymatic degradation was analyzed by HPLC.