Development of chia gum/alginate-polymer support for horseradish peroxidase immobilization and its application in phenolic removal

Abstract

Chia gum’s molecular structure with distinctive properties as well as the alginate-based hydrogel’s three-dimensionally cross-linked structure can provide a potent matrix for immobilization of enzyme. Herein, chia gum (CG)/alginate (A)-polymeric complex was synthesized and employed as a support material for the immobilization of horseradish peroxidase (HRP). HRP was successfully immobilized on the developed ACG-polymeric support, and the highest immobilization recovery (75%) was observed at 1.0% CG and 2% A, pH 7.0, and 50 units of the enzyme. The structure, morphology, and thermal properties of the prepared ACG-HRP were demonstrated using Fourier Transform Infrared (FTIR), Scanning Electron Microscope, and Thermogravimetric (TGA) analyses. ACG-HRP showed a good reusability (60%) over ten reuses. The immobilized ACG-HRP displayed an acidic pH optimum (6.0), a higher temperature optimum (50 °C), and improved thermal stability (30–50 °C) compared to the soluble HRP at pH 7.0, 40 °C and (30–40 °C), respectively. ACG-HRP has a lower affinity for hydrogen peroxide (H2O2) and guaiacol and a higher oxidizing affinity for a number of phenolic substrates. The ACG-HRP demonstrated greater resistance to heavy metals, isopropanol, urea, Triton X-100, and urea, as well as improved efficiency for eliminating phenol and p-chlorophenol. The developed ACG-polymeric support provided improved enzyme properties, allowed the reuse of the immobilized HRP in 10 cycles, and made it promising for several biotechnological applications.

Alloyed Trimetallic Nanocomposite as an Efficient and Recyclable Solid Matrix for Ideonella sakaiensis Lipase Immobilization

“…However, from 292 to 358 °C representing the second phase, Ni-Co-Zn decomposed at a relatively faster rate, experiencing 22.12% weight loss, compared to the 13.6% weight loss for Ni-Co-Zn@Lipase at the same temperature points. While the decomposition at this phase is associated with the organic ligand, the reduced weight loss for Ni-Co-Zn@Lipase compared to Ni-Co-Zn may indicate an improved thermal stabilization associated with increased enzyme interaction and it being tightly bound onto the solid support, thus resulting in improved structural organization and stability. − Weight loss in the third phase progressed slowly for both materials from 358 to 800 °C with Ni-Co-Zn experiencing am additional 4.4% weight loss compared to the 8.76% weigh loss for the Ni-Co-Zn@Lipase, which is associated with carbonization and transformation of the residual components of the MOF. In total, Ni-Co-Zn lost 31.42% weight as compared to the 30.96% for Ni-Co-Zn@Lipase.…”