Enzymatic production of xylooligosaccharides from red alga dulse (Palmaria sp.) wasted in Japan

Red alga dulse (Palmaria sp.) has xylan with a small amount of cellulose and less lignin, hence these characteristics may provide some advantages in the enzymatic production of xylooligosaccharides (XOS). To evaluate dulse xylan as XOS source, we prepared xylan rich fraction (DXRF) and attempted XOS production using commercial enzymes. 13.8% of xylan rich fraction (DXRF: containing 52.2% of xylan) was obtained from dried dulse powder. We then evaluated the hydrolysis products of two commercial enzymes, revealing that hydrolysate of Hemicellulase amano 90 contained less xylose. The effective XOS production by the enzyme was evaluated in terms of enzyme dose, DXRF concentration and reaction period, showing that 66.6% of XOS was obtained from DXRF with the hydrolysis rate of 82% under the following condition: 54 U Hemicellulase amano 90, 10 mg/ml DXRF, pH 4.5, 50 degrees C for 24 h. These results indicated that red algae xylan is suitable for XOS source.