Ashour S A, el-Shora H M, Metwally M, Habib S A
Faculty of Science, Mansoura University, Egypt.
Microbios. 1996;86(346):59-69.
The pattern and the extent of formation of proteases and secretion varied with the fungus, age and/or the nature of the co-supplement. Addition of yeast extract induced the best yield of proteases from both Aspergillus niger and A. terreus. Proteases from A. niger were highly induced by glutamic acid, alanine or albumin, with minor differences, whereas gelatin, peptone, aspartic acid, casein or acetamide stimulated the accumulation of proteases in the culture medium of A. terreus. Galactose stimulated the yield of the enzyme particularly with A. terreus while most C-supplements inhibited such processes, more prominently in the presence of cellulose or starch. Incorporation of nicotinic acid and wheat bran initiated the maximum productivity of proteases from A. niger and A. terreus, respectively. Co+2 and Cu+2 highly stimulated the output of proteases from A. niger and A. terreus, respectively. Co+2 and Ca+2 stimulated the enzyme activity of alkaline and acid proteases from A. terreus and acid proteases from A. niger. The other six cations and DTT inhibited variably the three proteases particularly alkaline proteases from A. terreus indicating that proteases from various sources even from closely related species showed different properties.
蛋白酶的形成模式和程度以及分泌情况因真菌种类、年龄和/或共补充剂的性质而异。添加酵母提取物可使黑曲霉和土曲霉产生的蛋白酶产量最高。黑曲霉的蛋白酶受谷氨酸、丙氨酸或白蛋白的诱导程度很高，差异较小，而明胶、蛋白胨、天冬氨酸、酪蛋白或乙酰胺则刺激土曲霉培养基中蛋白酶的积累。半乳糖尤其能提高土曲霉产生的酶产量，而大多数碳源补充剂则抑制这一过程，在存在纤维素或淀粉的情况下抑制作用更明显。添加烟酸和麦麸分别使黑曲霉和土曲霉的蛋白酶产量达到最高。钴离子和铜离子分别极大地刺激了黑曲霉和土曲霉蛋白酶的产量。钴离子和钙离子分别刺激了土曲霉碱性蛋白酶和酸性蛋白酶以及黑曲霉酸性蛋白酶的酶活性。其他六种阳离子和二硫苏糖醇对这三种蛋白酶有不同程度的抑制作用，尤其是对土曲霉的碱性蛋白酶，这表明即使来自密切相关物种的不同来源的蛋白酶也表现出不同的特性。
