摘要
实验利用平板菌落法从腐烂的南果梨中筛选果胶酶的生产菌株,以沉淀圈确定胞外果胶酶的存在;通过固态发酵培养,采用次碘酸钠滴定法测定比较果胶酶活力,筛选得到1株果胶酶高产霉菌,命名为As2,其菌丝为有隔多核菌丝,以分生孢子形式繁殖;同时对As2固态发酵生产果胶酶的条件进行优化,确定最适发酵培养基的组成为:47.5 g麸皮,苹果渣2.5 g,质量分数为2.5%(NH4)2SO4溶液50 mL,pH 4.0.最佳固体发酵条件为:128 mL广口玻璃瓶装量50 g,接种比例20%,30℃恒温发酵96 h,干曲果胶酶活性可以达到6 635 U/g.
Pectinase is a kind of extracellular enzyme from microorganism, and it has been applied in food and beverage production widely. In the experiment, the mould which produces pectinase was screened from rotten Nanguo pear on plate, with selective media. Strains were used in solid-state fermentation, the pectinase activity was determinded with the method of sodium iodide titration. A strain with high ability of producing pectinase was isolated and named as As2. The solid-state fermentation medium components and its fermentation conditions were optimized. The results showed that the optimum medium consists of： 42.5 g bran, 2.5 g apple promace, 2.5 % （NH4）2SO4 and 50 mL distilled water. The optimum fermentation conditions were： 50 g fermentation medium in 128 mL, inoculation ratio 20 %, pH = 4.0, temperature 30 ℃ for 96 h. The highest yield was up to 6 635 U/g.
出处
《沈阳化工学院学报》
2008年第1期35-39,共5页
Journal of Shenyang Institute of Chemical Technolgy
关键词
霉菌
果胶酶
固体发酵
正交试验
mould
pectinase
solid-state fermentation
orthogonal design
