Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre, Dokki, Giza, 12622, Egypt.
Centre of Excellence, Encapsulation and Nanobiotechnology Group, National Research Centre, Dokki, Giza, 12622, Egypt.
Bioprocess Biosyst Eng. 2024 Feb;47(2):249-261. doi: 10.1007/s00449-023-02959-1. Epub 2024 Jan 10.
β-galactosidase has been immobilized onto novel alginate/tea waste gel beads (Alg/TW) via covalent binding. Alg/TW beads were subjected to chemical modification through amination with polyethyleneimine (PEI) followed by activation with glutaraldehyde (GA). Chemical modification parameters including PEI concentration, PEI pH, and GA concentration were statistically optimized using Response Surface methodology (RSM) based on Box-Behnken Design (BBD). Analysis of variance (ANOVA) results confirmed the great significance of the model that had F value of 37.26 and P value < 0.05. Furthermore, the R value (0.9882), Adjusted R value (0.9617), and predicted R value (0.8130) referred to the high correlation between predicted and experimental values, demonstrating the fitness of the model. In addition, the coefficient of variation (CV) value was 2.90 that pointed to the accuracy of the experiments. The highest immobilization yield (IY) of β-galactosidase (75.1%) was given under optimized conditions of PEI concentration (4%), PEI pH (9.5), and GA concentration (2.5%). Alg/TW beads were characterized by FT-IR, TGA, and SEM techniques at each step of immobilization process. Moreover, the immobilized β-galactosidase revealed a very good reusability as it could be reused for 15 and 20 consecutive cycles keeping 99.7 and 72.1% of its initial activity, respectively. In conclusion, the environmental waste (tea waste) can be used in modern technological industries such as the food and pharmaceutical industry.
β-半乳糖苷酶通过共价键固定在新型海藻酸钠/茶渣凝胶珠（Alg/TW）上。Alg/TW 珠通过与聚乙烯亚胺（PEI）进行胺化，然后用戊二醛（GA）进行活化来进行化学修饰。通过基于 Box-Behnken 设计（BBD）的响应面法（RSM）统计优化化学修饰参数，包括 PEI 浓度、PEI pH 和 GA 浓度。方差分析（ANOVA）结果证实了模型的重要性，该模型的 F 值为 37.26，P 值<0.05。此外，R 值（0.9882）、调整 R 值（0.9617）和预测 R 值（0.8130）表明预测值与实验值之间存在高度相关性，证明了模型的拟合度。此外，变异系数（CV）值为 2.90，表明实验的准确性。在优化的 PEI 浓度（4%）、PEI pH（9.5）和 GA 浓度（2.5%）条件下，β-半乳糖苷酶的固定化产率（IY）最高为 75.1%。Alg/TW 珠在固定化过程的每个步骤中都通过 FT-IR、TGA 和 SEM 技术进行了表征。此外，固定化的β-半乳糖苷酶具有非常好的可重复使用性，可重复使用 15 次和 20 次，分别保持其初始活性的 99.7%和 72.1%。总之，环境废物（茶渣）可用于食品和制药等现代技术产业。
