摘要
从七种食用和药用真菌中筛选出纤维素分解能力较强的灵芝菌株（Ｇａｎｏｄｅｒｍａｌｕｃｉｄｕｍ５００５９），比较了几种不同碳源的固体发酵培养基对灵芝５００５９产内切β－葡聚糖酶（又称羧甲基纤维素酶，ＣＭＣ酶）能力的影响，确定了最佳培养时间为５～６ｄ。通过硫酸铵沉淀、凝胶过滤和离子交换层析初步提纯了灵芝的ＣＭＣ酶，得到三个组分。其中一个组分在ＳＤＳ－ＰＡＧＥ电泳中为一条带，为单亚基分子，分子量为４．５×１０４，等电点为３．２，以ＣＭＣ－Ｎａ为底物的米氏常数（Ｋｍ）为７．２ｇ／Ｌ。该酶活力的最适温度为５０℃，半致死温度约６７℃。该ＣＭＣ酶组分在ｐＨ３．０～６．０范围内稳定，最适ｐＨ约为２．０和４．０。
A cellulase producing strain Ganoderma lucidum 50059 was compared with seven edible fungi. The effect of different nutrients on cellulase production was analyzed. The optimum culture period for CMCase production was 5~6 days. Using the technique of (NH4)2SO4 fractionation, gel filtration and ion exchange chromatography, three components of CMCase were obtained. One of these was pure, with molecular weight of 4.5×104, isoelectric point of 3.2, kinetic Km of 7.2g/L. The effect of pH, temperature and ions on enzyme activity and stability were studied. The optimum pH value was about 2.0, 4.0. These enzymes were stable at pH3.0~6.0. The optimum temperature of the pure fraction is 50℃. The semilethal temperature was about 67℃.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
1998年第6期56-58,62,共4页
Journal of Tsinghua University(Science and Technology)
