黑曲霉酸性蛋白酶酶学性质的研究

Studies on Characters of Acid Protease Excreted by Aspergillus Niger ANS_1

对黑曲霉菌株ANS1产酸性蛋白酶基本酶学性质的研究表明:酸性蛋白酶适宜pH在2.5～4.0之间,在pH为3.5时,相对酶活最高;适宜温度在40～50℃之间,在45℃时,相对酶活最高;酸性蛋白酶有着较好的热稳定性,曲酶粉在80℃保温至5min保留有51.4%的酶活,液态酶在80℃恒温水浴中保温1min保留有54.6%的酶活力,曲酶粉较液态酶有着更好的抗热性;金属离子对酸性蛋白酶活力有一定的影响,在2.0mmol·L-1的浓度下,Mn2+和Cu2+酸性蛋白酶有较强的激活作用,Fe3+对该酶表现出明显的抑制作用。研究结果表明,黑曲霉菌株ANS1产酸性蛋白酶可以作为生物饲料添加剂。

Studies on characters of acid pro：ease excreted by Aspergillus niger ANS1 indicated that the fitting reaction pH of acid protease was among 2.5-4.0, the relative enzyme activity reached 100% at pH 5.0; the fitting reaction temperature was among 40-50 ℃, and the highest emyme activity was reached at 45 ℃; the acid protease could keep better stability in high temperature. The solid enzyme could hold 51.4% activity at 80 ℃ for 5 rain, the liquid enzyme could hold 54.6% activity at 80 ℃ for 1 rain, the solid enzyme could better resist heat destroy than liquid enzyme. Some mental ions could influence acid pro：ease activity, the acid pro：ease could be notably activated by Mn^2＋ and Cu^2＋, while restrained by Fe^3＋ in 2.0 mmol·L^-1. The results indicate that acid pro：ease excreted by Aspergillus niger ANS1 is fit to feed as additives.