Michelena V V, Castillo F J
J Appl Bacteriol. 1984 Jun;56(3):395-407. doi: 10.1111/j.1365-2672.1984.tb01367.x.
Aspergillus foetidus ATCC 10254 was selected from nine starch-utilizing microorganisms for its high amylolytic activity. This mould produced high levels of extracellular alpha-amylase in rice starch medium and degraded the available starch efficiently. Optimal conditions for enzyme production on 2.0% rice medium included 28 degrees C, initial pH of 6.6, and supplementations with 0.02% NaNO2, 0.08% KH2PO4, and 0.08% corn steep liquor. Eleven-fold purification of the enzyme was obtained after ammonium sulphate and ethanol precipitations from spent medium. The molecular weight was estimated at 41 500. Optimum pH and temperature for enzyme activity were 5.0 and 45 degrees C. Michaelis-Menten constants were 1.14 mg/ml on amylopectin, 2.19 mg/ml on soluble starch and 7.65 mg/ml on amylose. Amylose produced substrate inhibition while glucose or maltose did not inhibit the enzyme. This alpha-amylase may be used as a saccharifying enzyme for rice starch. Aspergillus foetidus ATCC 10254 also presents a potential for treatment of starch-containing waste waters.
恶臭曲霉ATCC 10254因具有较高的淀粉分解活性，从九种利用淀粉的微生物中被筛选出来。这种霉菌在大米淀粉培养基中能产生大量胞外α-淀粉酶，并能有效降解可用淀粉。在2.0%大米培养基上产酶的最佳条件包括28℃、初始pH值6.6，以及添加0.02%亚硝酸钠、0.08%磷酸二氢钾和0.08%玉米浆。从发酵后的培养基中经硫酸铵和乙醇沉淀后，该酶得到了11倍的纯化。估计其分子量为41500。该酶的最适pH值和温度分别为5.0和45℃。支链淀粉的米氏常数为1.14mg/ml，可溶性淀粉为2.19mg/ml，直链淀粉为7.65mg/ml。直链淀粉产生底物抑制作用，而葡萄糖或麦芽糖不抑制该酶。这种α-淀粉酶可用作大米淀粉的糖化酶。恶臭曲霉ATCC 10254在处理含淀粉废水方面也具有潜力。
