Unlike many biopolymers, alpha-1,3-glucan (alpha-1,3-GLU) is water-insoluble, making it a promising candidate for the production of moisture-resistant films with applications in biodegradable packaging, biomedicine, and cosmetics. This study aimed to characterize the structural, physicochemical (water affinity, optical, mechanical), and biodegradation properties of a film made from alpha-1,3-GLU extracted from Laetiporus sulphureus. The film was fabricated through alkaline dissolution, casting, drying, washing to remove residual NaOH, and re-plasticization with a glycerol solution. FTIR and Raman spectroscopy confirmed the polysaccharide nature of the film, with predominant alpha-glycosidic linkages. The film exhibited a semi-crystalline structure and high opacity due to surface roughness resulting from polymer coagulation. Owing to re-plasticization, the film showed a high moisture content (similar to 47%), high water solubility (81.95% after 24 h), and weak mechanical properties (tensile strength = 1.28 MPa, elongation at break approximate to 10%). Its water vapor permeability (53.69 g mm m(-2) d(-1) kPa(-1)) was comparable to other glycerol-plasticized polysaccharide films reported in the literature. The film supported the adhesion of soil microorganisms and target bacteria and was susceptible to degradation by Trichoderma harzianum and endo- and exo-alpha-1,3-glucanases, indicating its biodegradability. The limitations in its mechanical strength and excessive hydration indicate the need for improvements in the composition and methods of producing alpha-1,3-GLU films.

In this research, we prepared novel hydrogels from enzymatically synthesized alpha-1,3-glucan and its carboxymethyl derivative by crosslinking with ethylene glycol diglycidyl ether. The resulting hydrogels were highly swellable and pH-sensitive with an enhanced, highly developed structure, and showed excellent protein/dye adsorption performances. Furthermore, the hydrogels had good biodegradability and could be degraded in soil extract solution. The prepared hydrogels have potential applications as green and environmentally-friendly adsorbents for the effective removal of organic dyes in printing and dyeing wastewater. Graphical Abstract Enzymatic synthesized alpha-1,3-glucan was converted into carboxymethyl glucan and subsequently crosslinked with ethylene glycol diglycidyl ether to form hydrogels. We evaluated the protein and dye adsorption capacity of the hydrogels and analyzed the absorption mechanism. Furthermore, the hydrogels' notable biodegradability, evidenced by their decomposition in soil extracts, underscores their potential as environmentally-friendly adsorbents for environmental remediation.