초록
<P><B>Abstract</B></P> <P>Here, we established a one-step reaction method using trehalose synthase to produce trehalose from maltose. <I>Bacillus subtilis</I> was used as an expression host, and the various <I>B. subtilis</I> signal peptides and chitin-binding domains (ChBD) from <I>Bacillus circulans</I> WL-12 chitinase A1 were fused with the N- and C-termini, respectively, of trehalose synthase from the <I>Picrophilus torridus</I> DSM 9790 (PTTS) gene. Results showed that trehalose synthase was secreted by the YwbN signal peptide of <I>B. subtilis</I> and bound specifically to the chitin beads. The conversion yield of the immobilized enzyme was up to 69.07%, which was higher than that of the free enzyme (65.40%). Furthermore, the immobilized enzyme also retained 50% of its residual activity after the 21st repeated use. The chitin beads maintained 55% adsorption capacity after being reused 53 times. The results indicate the potential usefulness of the developed approach for trehalose production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PTTSChBD fused with <I>ywbN</I> SP can be secreted in a folded state by <I>Bacillus subtilis.</I> </LI> <LI> PTTSChBD directs immobilization on chitin beads without replacing adsorption buffer. </LI> <LI> Immobilized enzyme retains 50% residual activity after 21 repeated uses. </LI> <LI> Chitin beads maintain 55% adsorption after being reused 53 times. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>