Abstract
BACKGROUND: The numerous hydroxyl groups in tannic acid (TA) and its tendency to form hydrogen bonds with proteins and carbohydrates are key factors contributing to its utility. TA-based enzyme immobilization supports provide flexible platforms for enzyme immobilization. chia gum (CG) can also trap significant amounts of water between its chains, preventing water loss from the gum and inhibiting enzyme leaching. RESULTS: In this study, TA, a natural linker molecule, was used to immobilize horseradish peroxidase (HRP) on chia gum (CG), serving as the natural support. On the created TA-CG support, HRP was successfully immobilized, with the maximum immobilization recovery (80%) observed at pH 7.0, 9 mg TA, and 20 U of the enzyme. Using a scanning electron microscope (SEM) and Fourier transform infrared (FTIR) technology, the chemical functional groups and morphological characteristics of the synthesized CG-TA-HRP were illustrated. After ten reuses, CG-TA-HRP demonstrated good reusability, with 65% retention. By comparing CG-TA-HRP to soluble HRP, the former exhibited better thermal stability up to 40 °C, a higher temperature optimum at 50 °C, and a pH optimum at 6.0. According to the K(m) data, CG-TA-HRP exhibited a lower affinity for hydrogen peroxide (H(2)O(2)) and guaiacol and a higher oxidizing affinity to certain phenolic substrates. The prepared CG-TA-HRP demonstrated greater resistance to heavy metals, isopropanol, urea, and Triton X-100. During the 6-hour incubation period, soluble HRP removed 44% of the methyl orange, while immobilized HRP decolorized 78% of the dye. CONCLUSIONS: The TA-linker molecule and chia gum are considered environmentally safe components in the production of CG-TA-HRP, making this an easy and eco-friendly method for enzyme immobilization.