一株产纤维素酶的曲霉筛选及发酵条件优化

Isolation and fermentation optimization of the cellulase production of Aspergillus sp.

从环境中筛选得到一株具有较高纤维素酶活性的曲霉,对其进行固态发酵条件优化。以麸皮+麦秸粉为碳源,含量0.4%的Na NO3为氮源,5%接种量(0.28 g菌体/10 m L),30℃培养96 h,优化后Cx酶活力1552.5 U/g干培养基,Fpase活力达到351.6 U/g干培养基,而C1酶活力达到27.7 U/g干培养基。初步酶学性质研究表明,该菌产纤维素酶的最适反应温度为40℃;Cx酶和FPase最适反应p H值为4.4,而C1酶p H值为5.0。

An Aspergillus sp. with high performance to hydrolyze cellulase was isolated from environment and its solid fermentation condition for cellulase was optimized. Bran and straw were used as the carbon sources and 0.4%NaNO3 as the nitrogen source, 5%in-oculating volume（0.28 g biomass/10 mL）. The strain was incubated at 30℃ for 96 h. After optimization, the Cx activity reached 1552.5 U/g dry medium, FPase activity 351.6 U/g dry medium and C1 activity 27.7 U/g dry medium. The cellulase showed an opti-mal temperature 40℃. The Cx and FPase showed an optimal pH 4.4, however C1 pH 5.0.