海藻酸钠固定化β-葡萄糖苷酶的研究

Immobilization of β-glucosidase by sodium alginate

以海藻酸钠为载体,研究了β-葡萄糖苷酶固定方法及其条件,并利用固定化β-葡萄糖苷酶进行了酶解试验。结果表明,采用交联-包埋方式,在海藻酸钠质量分数3.5%、给酶量100 U/g载体、戊二醛体积分数1%、氯化钙质量分数2%的条件下固定β-葡萄糖苷酶2 h,可以获得较佳的固定化效果。其固定率达到65%,重复分批利用20次仍能保持90%以上的酶解得率。利用固定化β-葡萄糖苷酶连续酶解纤维二糖时,在不同进料速度下有着不同的催化效率,当进料速度为1.5 mL/m in、1.0 mL/m in时,酶解得率分别达到96.7%和99.0%;与木霉纤维素酶协同水解纤维素时,在β-葡萄糖苷酶总酶活与滤纸酶活之比为0.5(FPA为2.0 U/mL)的条件下,酶解滤纸纤维素和微晶纤维素60 h的得率比单独采用木霉纤维素酶分别增加了20.4%和29.3%。研究结果对于解决酶法水解纤维资源得率低、酶使用成本高这一关键问题提供了一种有效的方法。

β-Glucosidase was immobilized by using sodium alginate as carrier. The immobilized methods and conditions were studid. The immobilized enzyme was used to hydrolyze cellobiose and cellulose farther. The results show that the best efficiency of immobilization was obtained by using the crosslinking- embedding method when sodium alginate concentration was 3.5%, β-glucosidase dosage was 100 U/g carrier, glutaraldehyde concentration was 1%, CaC12 concentration was 2%, and immobilized time was 2 h. In repeated batch process of hydrolysis cellobiose, the yield reached enzymatic hydrolysis kept highter than 90% during 20 batches. In continuous process of hydrolysis cellobiose, the yield of enzymatic hydrolysis changed with the feed-in rate. The yield reached 96. 7% and 99.0%, when the rate was 1.5 mL/min, 1.0 mL/min, respectively. The synergetic hydrolysis processes on filter paper and Avicel were carried out by the cellulose of T. viride and the immobilized β-glucosidase. Under the condition of total β-glucosidase activity to filter paper activity was increased to 0. 5 and FPA was 2. 0 U/mL at 60 h, the degradation rate of filter paper and Avicel was increased by 20. 4% and 29. 3%, respectively as compared to that using T. viride only. This research provided a more efficient way to improve the hydrolysis yield and lower cost of enzyme for cellulosic material hydrolysis.