产纤维素酶菌株的选育分析及发酵工艺优化

Cellulase strain selection and fermentation process optimization

对实验室6株产纤维素酶菌株进行酶活特性研究.首先通过观察纤维素平板的酶溶解透明圈大小进行初步分析,比较6株菌种子发酵液中纤维素酶含量.再根据不同种纤维素酶作用的底物化学键的不同,分别测定菌株的滤纸酶活(FPA)、纤维素内切葡聚糖酶(CMCase)活、纤维素外切葡聚糖酶(CBH)活和β-葡萄糖苷酶酶活,发现菌株中黑曲霉的各产酶指标均高于其它菌株.根据Box-Behnken原理对黑曲霉发酵工艺进行优化设计,得到最适碳源稻草粉含量9.47 g.L-1、麸皮含量49.33 g.L-1,氮源中(NH4)2SO4含量为2.0 g.L-1,发酵后黑曲霉产生的滤纸酶活力达到76.72 U.mL-1,比优化前酶活力提高88.69%.

The paper researched enzymic characteristics of 6 kinds of cellulose production strains in the laboratory. Through observing the size of enzymatic hydrolysis clear circle on cellulose flat, the laboratory technician compared 6 strains cellulase activities of seed fermentation liquid. According to the different kinds of cellulase react with substrate special chemical bonds, filter paper activity （FPA）, endoglucanase （CMCase）, cellobiohydrolase and β-glucosidase of fermentation strains were measured. The results show that cellulase production indicators of Aspergillus niger strain were higher than other strains. Based on Box-Behnken principle, Aspergillus niger fermentation optimum process was designed. The optimum carbon source was obtained when the straw powder content was 9.47 g· L ^- 1, bran content was 49.33 g· L ^- 1. （ NH4 ） 2 SO4 content was 2.0 g· L ^- 1 for nitrogen source, FPA of Aspergillus niger strain reached 76.72 U·mL^ - l after fermentation, and the FPA optimization result increased by 88.69% than before.