茶渣纤维素水凝胶固定化酶的研究

Study of Tea Waste Nanofibrils Cellulose Hydrogel for Enzyme Immobilization

采用不同目数的茶渣制备茶渣纤维素微纤丝水凝胶(TW-CNFs/hydrogels),将其作为微载体固定米根霉脂肪酶(ROL)和米曲霉α-淀粉酶(AOA)。通过扫描电镜(SEM)、傅里叶红外光谱(FT-IR)、对脂肪酶和淀粉酶及载体进行形态学分析等表征,结果表明:茶渣纤维素微纤丝表面存在大量蜂窝状的空隙,当茶渣纤维素微纤丝水凝胶被制成后,在空间分布上还带有明显的不规则和聚集堆叠的特性,酶分散和固定在各个空隙和堆叠的空间内;载体中茶渣的浓度越高,制备的茶渣纤维素微纤丝水凝胶固定化酶的酶活性越高;当pH为10时,已固定脂肪酶活性达到最高值,而游离脂肪酶的酶活降低85%左右;当pH为10时,固定淀粉酶的酶活比游离淀粉酶的高50%以上。相比游离酶,茶渣纤维素微纤丝水凝胶上固定的酶最适pH都向碱性偏移,说明固定化酶更具有耐碱性,pH稳定性和极端环境耐受性有显著性提高。

Tea waste cellulose nanofibrils hydrogels(TW-CNFs/Hydrogels)were pre-constructed by various mesh sizes of tea waste and then utilized them as nanofibrils for immobilize Rhizopus oryzae’s lipase(ROL)and Aspergillus oryzae’sα-amylases(AOA).To characterize the lipase,amylase and the carrier,we utilize the scanning electron microscope(SEM)and Fourier transform infrared(FT-IR)for morpheological analysis.The results showed that:There is a large number of honeycomb pores on the surface of the tea waste cellulose nanofibrils.Whentea waste cellulose nanofibrils hydrogels is aggregated,the spatial distribution of tea waste cellulose nanofibrils hydrogel had obvious characteristics with irregularity and stacking and the enzyme is dispersed and fixed in each and stacking space.The higher the concentration of tea residue from the carrier,the higher the enzyme activity of the prepared tea waste cellulose nanofibrils hydrogel immobilized.When pH was 10,the activity of fixed lipase reached the highest value,while the activity of free ratios decreased by about 85%.At pH 10,the enzymatic activity of fixed amylase was more than 50%higher than that of free amylase.Compared with the free enzyme,the optimal pH of the enzyme fixed on the tea waste cellulose nanofibrils hydrogel shifted to alkaline,indicating that the immobilized enzyme was more alkaline resistant and the pH stability and extreme environmental tolerance were improved significantly.