Fungal arabinan and L-arabinose metabolism

Appl Microbiol Biotechnol. 2011 Mar;89(6):1665-73. doi: 10.1007/s00253-010-3071-8. Epub 2011 Jan 7.

Abstract

L-Arabinose is the second most abundant pentose beside D-xylose and is found in the plant polysaccharides, hemicellulose and pectin. The need to find renewable carbon and energy sources has accelerated research to investigate the potential of L-arabinose for the development and production of biofuels and other bioproducts. Fungi produce a number of extracellular arabinanases, including α-L-arabinofuranosidases and endo-arabinanases, to specifically release L-arabinose from the plant polymers. Following uptake of L-arabinose, its intracellular catabolism follows a four-step alternating reduction and oxidation path, which is concluded by a phosphorylation, resulting in D-xylulose 5-phosphate, an intermediate of the pentose phosphate pathway. The genes and encoding enzymes L-arabinose reductase, L-arabinitol dehydrogenase, L-xylulose reductase, xylitol dehydrogenase, and xylulokinase of this pathway were mainly characterized in the two biotechnological important fungi Aspergillus niger and Trichoderma reesei. Analysis of the components of the L-arabinose pathway revealed a number of specific adaptations in the enzymatic and regulatory machinery towards the utilization of L-arabinose. Further genetic and biochemical analysis provided evidence that L-arabinose and the interconnected D-xylose pathway are also involved in the oxidoreductive degradation of the hexose D-galactose.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Arabinose / metabolism*
  • Aspergillus niger / metabolism*
  • Metabolic Networks and Pathways*
  • Polysaccharides / metabolism*
  • Trichoderma / metabolism*

Substances

  • Polysaccharides
  • araban
  • Arabinose