摘要
对重组大肠杆菌产生的β-半乳糖苷酶酶学性质的研究表明,该酶最适反应温度为55℃,最适pH值为7.0,在50℃时具有良好的热稳定性。K+,Mg2+,Mn2+等对酶有一定的激活作用,而重金属盐如Pb2+,Sn2+,Zn2+,Cu2+等对酶活有一定抑制作用。对乳糖分解试验研究表明,该酶水解乳糖的能力较强,牛奶中添加2NLU/mL时,55℃保温水解2h可达到55%以上的水解率。
It showed by properties determination of a-galactosidase from reco mbinant escherichia coli that, the optimum temperature and pH of the enzyme acti vity were 55 ℃and pH 7.0, respectively and exhibited thermostability at 50 ℃. The enzyme was significantly activated by some alkali and alkali-earth metal io ns such as K+,Mg2+and Mn2+, but inhibited by heavy metal ions such as Pb2+, Sn2+, Zn2+and Cu2+. It also showed through hydrolysis tests of lactose in mi lk that the a-galactosidase was exhibited strong ability to hydrolyze lactose in milk and reached above 55 percent of hydrolysis ratio by reacting with one un it per mililitre enzyme into milk holding under 55 centigrade for 2 hours.
出处
《中国乳品工业》
CAS
北大核心
2002年第6期15-18,共4页
China Dairy Industry
