Enzyme-assisted extraction of fucoidan from Kjellmaniella crassifolia based on kinetic study of enzymatic hydrolysis of algal cellulose

Fucoidan extraction from Kjellmaniella crassifolia was enhanced through beta-glucosidase fortified cellulase treat-ment. Kinetic study of the hydrolysis of isolated seaweed cellulose by commercial enzymes was carried out, and cellulolytic enzyme cocktail was optimized according to the degradation kinetics using response surface meth-odology for fucoidan extraction. Cellulose (9.88 wt%, d.b.) found in the seaweed was highly crystalline (CrI: 83.24 %). beta-glucosidase apparently improved the affinity of the cellulolytic enzymes for the cellulose by elimi-nating cellobiose feedback inhibition. Treating the seaweed with 30 FPU cellulase supplemented with 286.64 CBU beta-glucosidase per gram cellulose, followed by conventional ethanol precipitation, the fucoidan extraction yield based on seaweed feedstock dry matter reached 4.74 %. The total sugar content and sulfate content of the product reached 76.68 % and 22.83 %, respectively, with fucose accounting for 62.46 % of the total sugar. The product extracted under optimal conditions exhibited apparently concentration-dependent antioxidant activity, with IC50 values for DPPH, Hydroxyl and ABTS radical scavenging reaching 2.43 mg/mL, 1.02 mg/mL and 1.12 mg/mL, respectively. The results showed that the proposed enzymatic treatment based on cellulose hy-drolysis kinetics effectively disrupted the cell wall and facilitated the release and extraction of fucoidan from the seaweed.

Automated summary

Fucoidan extraction from Kjellmaniella crassifolia was improved by enhancing the cellulase treatment with beta-glucosidase. The enzymatic treatment based on cellulose hydrolysis effectively disrupted the cell wall and facilitated the release and extraction of fucoidan from the seaweed.