Simultaneous catalysis and product separation by cross-linked enzyme crystals

Biotechnol Bioeng. 2001 Feb 20;72(4):501-5. doi: 10.1002/1097-0290(20010220)72:4<501::aid-bit1013>3.0.co;2-j.

Abstract

Crystalline cross-linked xylose isomerase (CLXI, EC 5.3.1.5) and xylanase (CLX, EC 3.2.1.8) were studied in a packed-bed reactor for simultaneous catalytic reaction and separation of substrates from reaction products. Streptomyces rubiginosus xylose isomerase catalyzed a slow isomerization of L-arabinose to L-ribulose and an epimerization to L-ribose. In equilibrium the reaction mixture contained 52.5% arabinose, 22.5% ribulose, and 25% ribose. In a packed-bed column filled with CLXI, a simultaneous reaction and separation resulted in fractions where arabinose concentration varied between 100-0%, ribulose between 0-55%, and ribose between 0-100%. Trichoderma reesei xylanase II hydrolyzed and transferred xylotetraose mainly to xylotriose and xylobiose. In a packed-bed column filled with CLX, xylotetraose rapidly reacted to xylobiose and xylose by a mechanism that is not yet fully understood.

MeSH terms

  • Aldose-Ketose Isomerases / chemistry
  • Aldose-Ketose Isomerases / metabolism*
  • Arabinose / metabolism
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Catalysis
  • Crystallization
  • Disaccharides / biosynthesis
  • Disaccharides / isolation & purification*
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism*
  • Fungal Proteins / chemistry
  • Fungal Proteins / metabolism*
  • Oligosaccharides / biosynthesis
  • Oligosaccharides / isolation & purification*
  • Pentoses / metabolism
  • Ribose / isolation & purification*
  • Ribose / metabolism
  • Solubility
  • Streptomyces / enzymology
  • Trichoderma / enzymology
  • Xylan Endo-1,3-beta-Xylosidase
  • Xylose / biosynthesis
  • Xylose / isolation & purification*
  • Xylosidases / chemistry
  • Xylosidases / metabolism*

Substances

  • Bacterial Proteins
  • Disaccharides
  • Enzymes, Immobilized
  • Fungal Proteins
  • Oligosaccharides
  • Pentoses
  • ribulose
  • Ribose
  • Xylose
  • Arabinose
  • Xylosidases
  • Xylan Endo-1,3-beta-Xylosidase
  • Aldose-Ketose Isomerases
  • xylose isomerase
  • xylobiose