Gómez Leissy, Ramírez Hector L, Villalonga Reynaldo
Centre for Enzyme Technology, University of Matanzas, Matanzas, Cuba.
Prep Biochem Biotechnol. 2006;36(3):259-71. doi: 10.1080/10826060600716695.
Saccharomyces cerevisiae invertase, chemically modified with chitosan, was immobilized on a carboxymethylcellulose-coated chitin support via polyelectrolyte complex formation. The yield of immobilized protein was determined to be 72% and the enzyme retained 68% of the initial invertase activity. The optimum temperature for invertase was increased by 5 degrees C and its thermostability was enhanced by about 9 degrees C after immobilization. The immobilized enzyme was stable against incubation in high ionic strength solutions and was 12.6-fold more resistant to thermal treatment at 65 degrees C than the native counterpart. The prepared biocatalyst retained 98% and 100% of the original catalytic activity after 10 cycles of reuse and 70 h of continuous operational regime in a packed bed reactor, respectively. The immobilized enzyme retained 95% of its activity after 50 days of storage at 37 degrees C.
用壳聚糖化学修饰的酿酒酵母转化酶通过聚电解质复合物的形成固定在羧甲基纤维素包被的几丁质载体上。固定化蛋白的产率测定为72%，该酶保留了初始转化酶活性的68%。固定化后，转化酶的最适温度提高了5℃，其热稳定性提高了约9℃。固定化酶在高离子强度溶液中孵育时稳定，在65℃热处理下比天然酶的抗性高12.6倍。制备的生物催化剂在填充床反应器中重复使用10次和连续运行70小时后，分别保留了原始催化活性的98%和100%。固定化酶在37℃储存50天后保留了95%的活性。
