米曲霉耐热木聚糖酶纯化及酶学特性研究

摘要

对米曲霉原始发酵液中耐热木聚糖酶进行纯化和酶学特性研究,利用甘蔗渣为碳源培养米曲霉,通过超滤和阴离子交换柱两步纯化得到木聚糖酶XynH1,分子量35.402 kDa,利用飞行时间质谱和SDS-PAGE分析,推断XynH1为Xylanase XynF1,分子量为35.402 kDa.XynH1属于糖苷水解酶家族10,酶活为442.2 IU/mg,最适pH和温度分别为pH 6.0 和65 °C,80℃以下及pH 4.0～10.5范围内较稳定.%These studies were constrtuted of the investigalion of the purffication of a therm ostabje xylanase X ynH 1 using ferm entation broth of A spergillus oryzae. the brDth of sugar cane bagasse ferm entation of A . oryzae subjected to ultrafiltration and ion exchange chrom atography . The xylanase X ynH 1 was purified . Time-of-fjight mass spectrom etry coupled with SD S-PAGE analysis revealed that X ynH 1 was identcal to xylanase X ynF1 with a molecular weight of 35.402 kDa. Sequence analysis indicated that X ynH1 belonged to glycosyl hydrolases family 10 . The enzym atic activity of X ynH1 was measured 442 .2 IU /m g . X ynH1 was optim ally active at pH 6.0 and 65℃ , displaying stability with in pH 4.0～10 .5 and at tem perature below 80℃ .