淀粉酶高产菌株筛选及发酵条件优化研究%Screening of Amylase High Production Strains and Optimization of Production Conditions
河南省科学院生物研究所有限责任公司,郑州450008; 河南省微生物工程重点实验室,郑州 450008 河南省科学院生物研究所有限责任公司,郑州,450008
2011-10-02
淀粉酶 筛选 优化
从济源市麦田的土壤中筛选工业生产上有潜在应用价值的高产淀粉酶菌株,通过平板初筛和摇瓶复筛,得到高产淀粉酶细菌菌株P11 (2).对其产酶条件进行优化,最终得到最适碳源为可溶性淀粉,最适氮源为酵母粉和蛋白胨组合,加入MgSO4可以促进产酶,加入CaCl2或FeSO4抑制产酶.经正交试验确定培养基的最优组成,优化后的培养基组分为:可溶性淀粉20g/L,蛋白胨10g/L,酵母粉5g/L,磷酸氢二钾1.2g/L,硫酸镁0.5 g/L,氯化钠5g/L.该菌株在发酵4d时产酶能力最强;最适宜的发酵温度为于37℃;最佳发酵初始pH值为8.0.优化后的酶活是优化前的3倍,达到183.12 U/mL.%Amylases are important industrial enzymes with a wide range of applications.To obtain amylase with the potential application to food industry,the microorganisms from a sample of Jiyuan wheat field soil were screened and a bacteria strain,designated strain P11(2),producing high level of amylase was isolated.The enzyme producing medium was optimized by orthogonal tests.Soluble starch was found to be the good carbon source,and peptone plus yeast extract be the best nitrogen source.Enzyme production was stimulated by the presence of MgSO 4 and inhibited by the presence of CaCl 2 and FeSO 4.Maximum production of amylase(183.12 U/mL)was achieved after the culture conditions were optimized,which was three times higher than that of initial conditions.
