造纸用碱性脂肪酶的固定化研究

Study on Immobilization of Alkaline Lipase Used in Papermaking

中文关键词:  造纸  脂肪酶  固定化  树脂沉积物

Key Words:lipase  immobilization  pitch deposits

中文摘要:

      利用改性壳聚糖微球对脂肪酶进行固定化处理，以实现造纸过程中碱性脂肪酶的回收利用，详细考察了固定化脂肪酶的酶学性质。研究结果表明，利用先进行碳二亚胺盐酸盐（EDC）活化然后进行戊二醛交联壳聚糖微球的方法固定化脂肪酶，可使固定化脂肪酶的酶活和蛋白质含量达到最高，其酶活可达到64.6 U/g，蛋白质含量为253.7 μg/g，比酶活可达254.6 U/mg。经过固定化后，脂肪酶的最适反应温度由50℃升至55℃，最适pH值由7.5升至8.5。脂肪酶操作稳定性得到明显提高，固定化脂肪酶连续使用5次后其酶活仍保持在70%。

Abstract:

      In order to achieve the reuse of alkaline lipase in papermaking process, the alkaline lipase was immobilized on modified chitosan beads, and the enzymatic properties of immobilized lipase were examined. The results showed that the enzymatic activity, protein content and specific activity of the immobilized lipase could reach 64.6 U/g, 253.7 μg/g and 254.6 U/mg respectively, when lipase was first immobilized to the hydroxyl groups of chitosan by activation with EDC followed by the immobilization of more lipase molecules through its amino groups by cross-linking with glutaraldehyde. Moreover after the binary immobilization, the optimum reaction temperature of the lipase increased from 50 to 55℃, and the optimum pH value changed from 7.5 to 8.5, compared with the free lipase. The operation stability of the lipase was also improved significantly, lipase immobilized by the binary method could retain 70% residual activity after reusing for five times. Therefore, the immobilized lipase can be reused to remove the pitch deposits in white water in alkaline papermaking．