摘要
借助DNS试剂并利用分光光度法建立了一种测定淀粉中α-淀粉酶活性的方法。并用该法探讨了pH值、温度、淀粉浓度和钙的添加量对α-淀粉酶的热稳定性和活性的影响。研究表明:α-淀粉酶水解可溶性淀粉的最适酸度为pH 5.0;高浓度淀粉可以较好地保护酶的活性和热稳定性,一定量的钙离子可提高α-淀粉酶的热稳定性和催化效率。向5%(w/w)的可溶性淀粉中添加10mmol/L Ca2+,α-淀粉酶活性和热稳定性能最大限度的发挥。与对照酶(不加Ca2+,在2h内最适反应温度为75℃)相比,加Ca2+酶的热稳定性可提高10℃。该酶在使用时,一次性投料要比分次投料的效果好。
A determination method for activity of α-amylase in presence of starch had been established by spectrophotometry in accordance with DNS procedure.The effects of pH,temperature,starch concentration,and Ca2+ concentration on thermal stability and activity of α-amylase were studied in this paper.The results indicated that α-amylase displayed a pH activity optimum of 5.0.The presence of higher starch concentration further increased stability and activity of α-amylase,and addition of Ca2+ could improve thermal stability and catalytic efficiency of the enzyme.The highest activity and stability of α-amylase in 5(m/w)% soluble starch solution were found at a CaCl2 concentration of 10mmol·L-1.Stability of the enzyme in presence of Ca2+ could elevate 10℃ in comparision with the control enzyme(the optimal temperature in absence of Ca2+ was 75℃ in 2 hours).Addition of α-amylase once was better than other styles in its application.
出处
《中国酿造》
CAS
北大核心
2008年第10X期20-23,共4页
China Brewing
基金
湖北教育厅项目资助(2008B027,D2005118004)
