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

Abstract

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 o C for 24 h. These results indicated that red algae xylan is suitable for XOS source.

Identification of a Key Enzyme for the Hydrolysis of β-(1→3)-Xylosyl Linkage in Red Alga Dulse Xylooligosaccharide from Bifidobacterium Adolescentis

“…Red alga dulse possesses a unique xylan in the cell wall, and we have previously developed the preparation method of DX3 (β-(1→3)-xylosyl-xylobiose) [19]. In this study, we evaluated the prebiotic effect of DX3 on bacteria.…”

“…DX3 (2 3 -β-d-xylosyl-xylobiose) (99.0%>) was prepared as previously in [19]. The frozen dulse thalli were lyophilized and homogenized by a Wonder Blender WB-1 (OSAKA CHEMIKAL CO., Osaka, Japan) into powder.…”

“…Among red algae, dulse (Palmaria palmata) is known to contain a mix-linked β-(1→3)/β-(1→4)-xylan in the cell wall [15][16][17][18]. These studies have focused on the elucidation of their structure, whereas our previous study showed the method of dulse XOS production [19]. The xylotriose (DX3) possesses β-(1→3)-xylosyl linkage at the nonreducing end.…”

“…The chromophores from PE showed antioxidant activity [32]. To obtain more functionality of dulse, we prepared xylooligosaccharide from dulse, which possessed the unique structure of β-(1→3)/β-(1→4)-xylotriose (DX3) [19]. In this study, we investigated the prebiotic effect of DX3 on enteric bacteria, showing that Bifidobacterium adolescentis grew quickly among the tested bacteria.…”

Preparation of β(1→3)/β(1→4)-xylooligosaccharides from red alga dulse by two xylanases from Streptomyces thermogriseus 

“…Xylan is the second main ingredient of dulse. We attempted to prepare XOS from dulse xylan using commercial enzymes (Yamamoto et al 2019). Then, we puri ed β(1→3) xylosyl xylobiose (DX3) and clari ed prebiotics on Bi dobacterium sp.…”