Synthesis of two novel bio-based hydrogels using sodium alginate and chitosan and their proficiency in physical immobilization of enzymes

Abstract

Herein, four novel and bio-based hydrogel samples using sodium alginate (SA) and chitosan (CH) grafted with acrylamide (AAm) and glycidyl methacrylate (GMA) and their reinforced nanocomposites with graphene oxide (GO) were synthesized and coded as SA-g-(AAm-co-GMA), CH-g-(AAm-co-GMA), GO/SA-g-(AAm-co-GMA), and GO/CH-g-(AAm-co-GMA), respectively. The morphology, net charge, and water absorption capacity of samples were entirely changed by switching the biopolymer from SA to CH and adding a nano-filler. The proficiencies of hydrogels were compared in the immobilization of a model metagenomic-derived xylanase (PersiXyn9). The best performance was observed for GO/SA-g-poly(AAm-co-GMA) sample indicating better stabilizing electrostatic attractions between PersiXyn9 and reinforced SA-based hydrogel. Compared to the free enzyme, the immobilized PersiXyn9 on reinforced SA-based hydrogel showed a 110.1% increase in the released reducing sugar and almost double relative activity after 180 min storage. While immobilized enzyme on SA-based hydrogel displayed 58.7% activity after twelve reuse cycles, the enzyme on CH-based carrier just retained 8.5% activity after similar runs.

Microbial Upcycling of Waste PET to Adipic Acid

“…Finally, we examined the use of cells supported in alginate hydrogel as a method to increase the activities of TPADO and BcER and thus the yield of AA. The use of calcified alginate hydrogels is known to increase the stability of enzymes in vitro , and to improve the downstream purification of whole-cell biotransformations; however, few studies report the use of alginate immobilization to increase the stability of heterologous enzymes in de novo pathways in E. coli . More specifically, this has not been applied to stabilizing BcER within a microbial adipic acid pathway despite reported instability in vivo . , To this end, we were delighted to observe that, when TA was added to cells of E. coli _pPCA1_pAA4 supported in alginate hydrogels (termed alg- E. coli ), AA conversion was increased from 0% to 79% (Figure B).…”

Functionalized Chitosan and Alginate Composite Hydrogel-Immobilized Laccase with Sustainable Biocatalysts for the Effective Removal of Organic Pollutant Bisphenol A

“…Improved chemical modification interactions resulted in a stable, covalently immobilized enzyme that was not easily dislodged [16]. Enzyme immobilization on chitosan hydrogel soft carriers has the potential to improve the physical and chemical properties of the enzymes and product yields, and it has been reported to be used as a carrier for immobilized enzymes including laccase, trypsin, and lipase; thus, this green and effective method has attracted the interest of a large number of researchers [17][18][19]. In the previous literature, the most used strategies for the improvement of composite-formed, graft-copolymerized, and chitosan-formed hydrogel beads to enhance their catalytic stability and recyclability are currently available [20,21].…”

A novel starch‐based composite hydrogel enhanced by activated charcoal from the banana peel for water decontamination

“…Furthermore, hydrogels can be used to treat wastewater under conditions of varying pH, ionic strength, light, and temperature. 26,34 Chitosan and alginate, 35 cellulose, 36 and starch 37 are examples of polysaccharides explored for hydrogel synthesis. Among them, starch is a polymeric carbohydrate composed of amylose and amylopectin chains.…”

“…Chitosan and alginate, 35 cellulose, 36 and starch 37 are examples of polysaccharides explored for hydrogel synthesis. Among them, starch is a polymeric carbohydrate composed of amylose and amylopectin chains.…”