[关键词]
[摘要]
本论文初步探讨了利用裂褶菌发酵体系所产的内切β-1,3-葡聚糖酶对发酵产生的裂褶多糖进行适度酶解,以获得分子量适中溶解度较好的裂褶多糖的可能性。以裂褶多糖产量和β-1,3-葡聚糖内切酶和总酶活为考察指标,采用刚果红琼脂染色法和摇瓶培养,从四株裂褶菌GIM5.42、GIM5.43、GIM5.44、Sc1中筛选出多糖产量和酶活都相对较高的菌株GIM5.43,多糖产量和酶活分别为2.29 g/L与0.28 U/mL。在摇瓶中考察了氮源及其添加方式对裂褶菌菌体生长、裂褶多糖产率、β-1,3-葡聚糖酶的酶活及其影响规律。结果表明:菌体生长及其分泌胞外多糖和葡聚糖酶的最适酵母浸膏和氯化铵的添加时间和添加量是不同的。为了保证多糖产率,采用分批补加策略,初始酵母浸膏浓度1.00 g/L,发酵第6 d补加0.10 g/L酵母浸膏,多糖产量为4.16 g/L,比未优化提高了61.24%,总酶活为0.34 U/mL,提高了142.86%。
[Key word]
[Abstract]
The enzymatic hydrolysis of schizophyllan by endo-β-1,3-glucanase produced by Schizophyllum commune fermentation was investigated to to achieve moderate molecular weight and better solubility of schizophyllan. The strain GIM5.43 with higher yield of polysaccharide and enzyme activity was selected from four stains(GIM5.42, GIM5.43, GIM5.44, Sc1),. The polysaccharide yield and the enzyme activity were 2.29 g/L and 0.28 U/mL, respectively. The addition time and dosage of optimum yeast extract and ammonium chloride for the growth of Schizophyllum commune, the yield of schizophyllan and the enzyme activity of β-1,3- glucanase were different. The batch feeding strategy was adopted to ensure the yield of schizophyllan. The initial concentration of yeast extract was 1 g/L and 0.10 g/L yeast extract was added on the 6th day. Under these conditions, the yield of schizophyllan was 4.16 g/L, which was improved by 61.24%, and the total enzyme activity was 0.34 U/mL, which was increased by 142.86%.
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[基金项目]
广东省科技计划项目(2014A010107007、2013B090600129、2013B090800033);广州市科技计划项目(201604016114)