Department of Biotechnology Engineering, Kolhapur Institute of Technology's College of Engineering, Kolhapur 416 234, India.
Chemical Engineering and Process Development Division, CSIR-National Chemical Laboratory, Pune 411 008, India.
Bioresour Technol. 2013 Nov;147:269-275. doi: 10.1016/j.biortech.2013.08.035. Epub 2013 Aug 13.
A tri-enzyme biocatalyst "combi-CLEAs" with starch hydrolytic activity was prepared from commercially available alpha amylase, glucoamylase and pullulanase preparations by aggregating enzymes with ammonium sulphate followed by cross-linking formed aggregates for 4.5h with 40 mM glutaraldehyde. The effects of precipitant type and cross-linking were studied and the biocatalyst was characterized. Scanning electron microscopy analysis showed that tri-enzyme biocatalyst was of spherical structure. For one pot starch hydrolytic activity, shift in optimum pH from 6 to 7 and temperature from 65 to 75 °C were observed after co-immobilization of enzymes. After one pot starch hydrolysis reaction in batch mode, 100%, 60% and 40% conversions were obtained with combi-CLEAs, separate CLEAs mixture and free enzyme mixture, respectively. Co-immobilization also enhanced the thermal stability of enzymes. Finally, the catalytic activity of enzymes in combi-CLEAs during one pot starch hydrolysis was well maintained up to five cycles without performance changes.
一种具有淀粉水解活性的三酶复合细胞色素 P450 酶“组合-CLEAs”，是通过用硫酸铵聚集酶，然后用 40mM 戊二醛交联形成的聚集体，在 4.5 小时内制备的，来自市售的α-淀粉酶、糖化酶和普鲁兰酶制剂。研究了沉淀剂类型和交联的影响，并对生物催化剂进行了表征。扫描电子显微镜分析表明，三酶生物催化剂具有球形结构。在一锅淀粉水解活性中，酶共固定化后，最适 pH 值从 6 移至 7，最适温度从 65°C 移至 75°C。在分批式一锅淀粉水解反应后，分别用组合-CLEAs、单独的 CLEAs 混合物和游离酶混合物获得了 100%、60%和 40%的转化率。共固定化还提高了酶的热稳定性。最后，在一锅淀粉水解过程中，酶在组合-CLEAs 中的催化活性在五个循环中保持良好，没有性能变化。
