초록
<P><B>Abstract</B></P> <P>An <I>endo</I>-xylanase (<I>Ps</I>GH10A) of family 10 glycoside hydrolase from <I>Pseudopedobacter saltans</I> was cloned, expressed and purified. Substrate specificity analysis of <I>Ps</I>GH10A showed activity against β-1,4-xylans. It showed maximum activity against beechwood xylan (59.7 ± 1.1 U/mg) followed by xylan (Mw. 20,000–30,000) (57.1 ± 0.7 U/mg). <I>Ps</I>GH10A displayed maximum activity at pH 6.0 and 40 °C. The enzyme was stable in the pH range, from 6.0 to 7.5 and showed thermostability up to 40 °C. The kinetic parameters of <I>Ps</I>GH10A using beechwood xylan determined were K<SUB>m</SUB> 6.2 mg/mL and V<SUB>max</SUB> 72 U/mg. The activity of <I>Ps</I>GH10A was 29 ± 2.4% enhanced by 2 mM Mn<SUP>2+</SUP> ions and inhibited by less than 50 ± 1.6% by 2 mM Zn<SUP>2+</SUP>, Pb<SUP>2+</SUP> or Cu<SUP>2+</SUP> ions. The time-dependent TLC analysis of hydrolyzed products of beechwood xylan released by <I>Ps</I>GH10A showed the release of xylose, xylobiose and xylotetraose as end products confirming the endolytic mode of action. <I>Ps</I>GH10A hydrolyzed products of xylan and substituted xylan indicate production of series of short-chain xylooligosaccharides and arabinoxylo-saccharides. <I>Ps</I>GH10A also showed saccharification of AFEX pretreated poplar and sugarcane bagasse. Therefore, it can be used for various biotechnological applications such as for prebiotic xylooligosaccharides and bioethanol production from pretreated agrowaste biomass. This is the first report on β-1,4-xylanase cloned from <I>Pseudopedobacter saltans</I>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Endo β-1,4-xylanase (<I>Ps</I>GH10A) is first characterized xylanase from <I>Pseudopedobacter saltans</I>. </LI> <LI> <I>Ps</I>GH10A activity was enhanced by 30% by Mn<SUP>2+</SUP> ions. </LI> <LI> Xylose, xylobiose and xylotetraose release confirmed endolytic mode of catalysis. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>