Elucidating the effect of enzymatic polymerized polysaccharide particle morphology on emulsion properties

Bottom-Up Synthesized Glucan Materials: Opportunities from Applied Biocatalysis

Linear d-glucans are natural polysaccharides of simple chemical structure. They are comprised of d-glucosyl units linked by a single type of glycosidic bond. Noncovalent interactions within, and between, the d-glucan chains give rise to a broad variety of macromolecular nanostructures that can assemble into crystalline-organized materials of tunable morphology. Structure design and functionalization of d-glucans for diverse material applications largely relies on top-down processing and chemical derivatization of naturally derived starting materials. The top-down approach encounters critical limitations in efficiency, selectivity, and flexibility. Bottom-up approaches of d-glucan synthesis offer different, and often more precise, ways of polymer structure control and provide means of functional diversification widely inaccessible to top-down routes of polysaccharide material processing. Here the natural and engineered enzymes (glycosyltransferases, glycoside hydrolases and phosphorylases, glycosynthases) for d-glucan polymerization are described and the use of applied biocatalysis for the bottom-up assembly of specific d-glucan structures is shown. Advanced material applications of the resulting polymeric products are further shown and their important role in the development of sustainable macromolecular materials in a bio-based circular economy is discussed.

Enzymatic polymerization designed alpha-1,3 glucan particle morphology as reinforcing fillers of dipped and casted rubber films

In this work, enzymatic polymerization derived microcrystalline glucan (MCG) polysaccharides fillers were employed as novel sustainable fillers of natural rubber (NR) films. MCG has a designed platelet morphology, with high crystallinity and colloidal stability in aqueous media and rubber lattices. NR films composed of 0-10 phr MCG were then fabricated using dipping and casting processes. The incorporation of MCG in the NR led to a remarkable enhancement in the tear strength, tensile properties, toughness, and an increase in water vapor permeability but a decrease in ethanol permeation. This behavior is appealing in gloves, where high sweat permeation from hands to the environment and limited to no solvent penetration from the environment to the skin is desired. The study indicated that the enzymatically polymerized MCG are effective reinforcing fillers for NR latex and potentially other elastomers offering the potential for appealing physical property improvements.