Abstract: Cellulase has been widely used in environmental protection, medicine, food and other fields. However, the widespread use of cellulase was limited by its relatively high production costs and low biological activity. In this study, in order to provide a method for immobilizing cellulase that allowed the enzyme to be reused in multiple cycles, multi-walled carbon nanotubes was used as carriers to immobilize cellulase for the first time. The conditions for immobilization of enzyme with multi-walled carbon nanotubes were studied. An orthogonal experimental design was applied to optimize critical conditions for the immobilization process. The structures of MWCNTs, cellulase and immobilized cellulase were characterized by Fourier transform infrared (FT-IR) spectroscopy. The results showed that the optimum process conditions for immobilized enzyme were as follows: enzyme concentration 5 mg·mL-1, temperature 40 ℃, pH 5.0, immobilization time 3 h, and the immobilization of cellulase was confirmed successfully onto the multi-walled carbon nanotubes by Fourier transform infrared spectroscopy.

Key words: carbon nanotubes, immobilization, cellulase, the activity of immobilized enzyme

摘要： 纤维素酶在环保、医药、食品等领域都具有广泛的应用前景，但由于纤维素酶的生产成本较高,生物活性较低，使得纤维素酶的应用受到了限制。为了寻找一种固定化纤维素酶的方法，使酶可以重复多次使用，首次以多壁碳纳米管为载体固定化纤维素酶，研究功能化的多壁碳纳米管固定化纤维素酶的固定化条件，采用正交试验对酶固定化中的主要条件进行优化，并通过傅里叶变换红外光谱仪对多壁碳纳米管（multiwalled carbon nanotube，MWCNTs）、纤维素酶及固定化纤维素酶的结构进行表征。结果表明，固定化纤维素酶的最佳工艺条件为：酶浓度5 mg·mL-1，温度40 ℃，pH 5.0，固定化时间3 h；通过傅里叶变换红外光谱证实纤维素酶成功固定到多壁碳纳米管上。

关键词: 碳纳米管, 固定化, 纤维素酶, 固定化酶活力