Production of Xylose from Xylan by Endoxylanase and ${\beta}-Xylosidase$ Expressed in Yeast

  • Published : 2003.04.11

Abstract

The endoxylanase (642 bp; 213 amino acids) and ${\beta}-xylosidase$ (1,602 bp; 533 amino acids) genes from Bacillus sp. were amplified by PCR and separately inserted downstream of the yeast ADH1 promoters, resulting in the pAEDX-1 and pAEX plasmid. When the yeast transformants, S. cerevisiae SEY2102 harboring pAEDX-1 or pAEX, were grown on YPD medium, the total activities of the enzymes reached about 9.8 unit/mL for endoxylanase and 2.9 unit/mL for ${\beta}-xylosidase$. When the three kinds of xylan from oat spelts, birch wood, and corncob were hydrolyzed by treatment of recombinant endoxylanase and ${\beta}-xylosidase$, it was found that xylose, xylobiose and xylotriose were produced and xylose was the major product after 12 h reaction. In addition, with the higher amount of enzymes, the more amount of xylose was produced.

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