斜卧青霉A10产纤维素酶的酶学性质研究

Studies on the Characterization of Cellulase from Penicilium decumbens A10

以斜卧青霉(Penicillium decumbens)A10为出发菌株,经450 Gy ^(60)Coγ-射线诱变处理,选育出一株具有较高纤维素酶活力且传代稳定的正突变株A50,发酵60 h后,其CMC酶活和滤纸酶活分别为27.28 IU/mL和1.98 IU/mL,较出发菌株A10分别提高了33.2%和45.59%。对突变株A50的产酶组分进行研究,通过SDSPAGE电泳分析,从蛋白质水平上证明突变株A50确实是A10在遗传物质上发生改变的菌株,其CMC酶活最适作用pH值为4.0,最适作用温度为60℃;而滤纸酶活的最适作用pH值为5.2,最适作用温度45℃,二者在一定范围内具有较高的稳定性。

The mutant strain with high cellulase activity and genetic stability A50 was isolated through ^60Coγ radiation dealing with the initial one which named Penicillium decumbens A10, the highest enzyme activities of CMC and filter paper is 27.28 IU/mL and 1.98 IU/mL respectively after 60 h fermentation which are 33.2 % and 45.59 % higher than the initial strain A10. The enzymatic composition of the mutant strain ASO were studied. The culture supernatant of the initial strain and the mutant contained different protein bands from the analysis of SDS-PAGE result, which exactly demonstrated at protein level that A50 was surely a mutant of A10. CMCase of the mutant have their optimum activities at pH 4.0 and 60 ℃ ,its FPA have their optimum activities at pH 5.2 and 45 ℃ , they have better stability in certain range.