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

Abstract

Red alga dulse possesses a unique xylan, which is composed of a linear β-(1→3)/β-(1→4)-xylosyl linkage. We previously prepared characteristic xylooligosaccharide (DX3, (β-(1→3)-xylosyl-xylobiose)) from dulse. In this study, we evaluated the prebiotic effect of DX3 on enteric bacterium. Although DX3 was utilized by Bacteroides sp. and Bifidobacterium adolescentis, Bacteroides Ksp. grew slowly as compared with β-(1→4)-xylotriose (X3) but B. adolescentis grew similar to X3. Therefore, we aimed to find the key DX3 hydrolysis enzymes in B. adolescentis. From bioinformatics analysis, two enzymes from the glycoside hydrolase family 43 (BAD0423: subfamily 12 and BAD0428: subfamily 11) were selected and expressed in Escherichia coli. BAD0423 hydrolyzed β-(1→3)-xylosyl linkage in DX3 with the specific activity of 2988 mU/mg producing xylose (X1) and xylobiose (X2), and showed low activity on X2 and X3. BAD0428 showed high activity on X2 and X3 producing X1, and the activity of BAD0428 on DX3 was 1298 mU/mg producing X1. Cooperative hydrolysis of DX3 was found in the combination of BAD0423 and BAD0428 producing X1 as the main product. From enzymatic character, hydrolysis of X3 was completed by one enzyme BAD0428, whereas hydrolysis of DX3 needed more than two enzymes.

Characterization of ACE Inhibitory Peptides Prepared from Pyropia pseudolinearis Protein

“…On the other hand, Japanese people have been using seaweed as a food source and industrial material since ancient times. Recently, the health functions of seaweed’s nutritional components have been reported [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. In particular, the idea of using seaweed proteins as bioactive peptides has attracted much attention [ 21 ].…”

Efficient Extraction and Antioxidant Capacity of Mycosporine-Like Amino Acids from Red Alga Dulse Palmaria palmata in Japan

“…The chromophores from PE showed antioxidant capacity [ 32 ]. In addition, β-(1→3)-xylosyl-xylobiose prepared from dulse xylan exhibited the prebiotic effect on enteric bacterium [ 33 ]. In this way, dulse contains many healthy functional ingredients.…”

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

“…Dulse (Palmaria palmata in Japan) was harvested at Usujiri, Hokkaido, Japan and stored at -30 °C until use (Yamamoto et al 2019;Kobayashi et al 2020). Xylose (X1), xylobiose (X2) and xylotriose (X3) were purchased from Wako Pure Chemical Industries (Osaka, Japan).…”

“…Then, we puri ed β(1→3) xylosyl xylobiose (DX3) and clari ed prebiotics on Bi dobacterium sp. (Kobayashi et al 2020).…”

“…Then, we puri ed β(1→3) xylosyl xylobiose (DX3) and clari ed prebiotics on Bi dobacterium sp. (Kobayashi et al 2020). ) is one of the main enzymes for xylan hydrolysis (Chapla et al 2012).…”