초록
<P><B>Abstract</B></P> <P> <I>Aspergillus niger</I> DSM 26641 was exposed to <SUP>60</SUP>Co γ-radiation to enhance the β-1,4-endoxylanase activity, restrict colony growth and improve robustness of pellets. The first promising mutant obtained after γ-radiation of the fungal spores at 50–2000Gy showed a restricted colony growth and an 82% enhancement in β-1,4-endoxylanase activity. The mutant was subjected to a second round of γ-radiation at 1400Gy generating a mutant with double the β-1,4-endoxylanase activity compared to the native strain. The selected final mutant, deposited as <I>A. niger</I> DSM 28712, showed a maximal saccharification activity of 26Uml<SUP>−1</SUP> on xylan based broth, 48Uml<SUP>−1</SUP> on lignocellulose hydrolysate and 375Uml<SUP>−1</SUP> on lignocellulose hydrolysate supplemented with yeast extract and mineral salts.</P> <P><B>Highlights</B></P> <P> <UL> <LI> β-1,4-Endoxylanase activity of <I>Aspergillus niger</I> DSM 26641 was doubled by γ-radiation. </LI> <LI> Restricted widespread filamentous growth on agar plates was observed. </LI> <LI> Miniaturization and pellet surface restriction favors biomass recycling. </LI> </UL> </P>