柚子皮黑曲霉的分离鉴定及产酶特性研究

Identification and Characterization of Aspergillus niger Isolated from Pomelo Peel

对柚子皮上自然生长的黑曲霉进行分离鉴定,并探讨其产酶特性。以平板稀释法从柚子皮上分离出一株霉菌菌株,通过观察其形态特征和培养特征,对照《真菌鉴定手册》判定该菌株的种属;采用鉴定培养基法对其产酶特性进行分析。根据柚子皮的成分特性,以干柚子皮为主要原料,该菌为生产菌株,采用固态发酵法探究培养基的成分、柚子皮含量、培养基初始含水量及发酵时间4个因素对纤维素酶活力的影响。结果表明,该菌株为黑曲霉(Aspergillus nige),可产淀粉酶、蛋白酶、纤维素酶、果胶酶;固态发酵培养基中添加柚子皮12g,麸皮0.5 g和(NH_4)_2SO_40.5 g,培养基初始含水量保持在68.5 mL/100 g,培养时间控制在60 h左右时纤维素酶产量较高。

Aspergillus niger naturally grow on pomelo peel was separated and characterized,and investigated for its enzyme-producing features. Plate dilution method was used to isolate a mold strain,and it was identified through observing its morphological and culture features,and compare to Fungi Characterization Handbook to judge the genus and species of the strain. The identification medium is adopted to discuss the enzyme production characteristics. Dried pomelo peels as major raw material,according to the component feature of pomelo peel,and the strain as producing strain,adopting solid state fermentation method to investigate the effects on cellulase activity of four factors,component of culture medium,the content of pomelo peel,the initial water content of the medium,as well as fermentation time. The result showed that the strain was Aspergillus niger and it can produce four enzymes： amylase,protease,cellulase and pectinase; 12 g pomelo peels,0. 5 g wheat bran,and 0. 5 g（ NH4）2SO4,and initial water content at about 68. 5 mL/100 g and fermentation time at about 60 h,the yield of cellulase was at the higher level..