IMMOBILIZATION OF HORSERADISH PEROXIDASE ON SUGARCANE BAGASSE

The immobilization of horseradish peroxidase (HRP) on raw and alkaline pre-treated sugarcane bagasse by physical adsorption (ADS) and covalent bond (LC) methods was studied. The saturation of the support with 2 mg of HRP/g of support by LC immobilization reached 35% of immobilization efficiency and 39 units of the immobilized enzyme (U). Regarding the HRP immobilization on sugarcane bagasse without pretreatment and using the same HRP loading, it was observed a reduction in the efficiency of immobilization and in the number of immobilized units for both methods, ADS (13.98% and 15.46 U) and LC (15.79% and 17.46 U). The sugarcane bagasse with alkaline pretreatment experiment, on the other hand, exhibited higher potential for HRP immobilization by LC. The supports and biocatalysts were characterized by Fourier transform infrared spectroscopy (FTIR), showing greater availability of hydroxyl groups in the pretreated support and the typical amide I and amide II bands that corroborate the effectiveness of the enzyme immobilization on sugarcane bagasse. In the same way, the thermogravimetric analysis (TGA) confirmed a higher weight loss in the region I for the derivative immobilized by LC, suggesting the presence of water favored enzymatic activity.本研究探讨了通过物理吸附（ADS）与共价结合（LC）两种方法，将辣根过氧化物酶（horseradish peroxidase, HRP）固定于原始及碱性预处理后的甘蔗渣载体上的过程。采用共价结合法，以2 mg HRP/g载体的负载量实现载体饱和时，固定化效率可达35%，固定化酶活力为39酶活力单位（U）。针对未预处理的甘蔗渣载体，采用相同HRP负载量进行固定化时，两种固定方法的固定化效率及固定化酶活力均出现下降：物理吸附法的固定化效率与酶活力分别为13.98%和15.46 U，共价结合法则分别为15.79%和17.46 U。相较而言，经碱性预处理的甘蔗渣载体更适合通过共价结合法实现HRP的固定化，展现出更高的固定化潜力。本研究采用傅里叶变换红外光谱（Fourier transform infrared spectroscopy, FTIR）对载体及生物催化剂进行表征，结果显示预处理后的载体中羟基基团可用性更强，且出现了典型的酰胺I与酰胺II特征峰，证实了辣根过氧化物酶在甘蔗渣载体上的固定化效果。此外，热重分析（thermogravimetric analysis, TGA）证实，经共价结合法制备的固定化酶衍生物在热重区域I的失重率更高，表明结合水的存在有利于酶促活性的发挥。