Characterization of a GH36 β-L-Arabinopyranosidase in Bifidobacterium adolescentis

Abstract

β-L-Arabinopyranosidases are classified into the glycoside hydrolase family 27 (GH27) and GH97, but not into GH36. In this study, we first characterized the GH36 β-L-arabinopyranosidase BAD_1528 from \textit{Bifidobacterium adolescentis }JCM1275. The recombinant BAD_1528 expressed in \textit{Escherichia coli} had a hydrolytic activity toward \textit{p}-nitrophenyl (\textit{p}NP)-β-L-arabinopyranoside (Ara\textit{p}) and a weak activity toward \textit{p}NP-α-\textsc{D-}galactopyranoside (Gal). The enzyme liberated L-arabinose efficiently not from any oligosaccharides or polysaccharides containing Ara\textit{p}-β1,3-linkages, but from the disaccharide Ara\textit{p}-β1,3-L-arabinose. However, we were unable to confirm the \textit{in vitro} fermentability of Ara\textit{p}-β1,3-Ara in\textit{ B. adolescentis} strains. The enzyme also had a transglycosylation activity toward 1-alkanols and saccharides as acceptors.