Engineering of pentose transport in Corynebacterium glutamicum to improve simultaneous utilization of mixed sugars

Appl Microbiol Biotechnol. 2009 Nov;85(1):105-15. doi: 10.1007/s00253-009-2065-x. Epub 2009 Jun 16.

Abstract

Corynebacterium glutamicum strains CRA1 and CRX2 are able to grow on L-arabinose and D-xylose, respectively, as sole carbon sources. Nevertheless, they exhibit the major shortcoming that their sugar consumption appreciably declines at lower concentrations of these substrates. To address this, the C. glutamicum ATCC31831 L-arabinose transporter gene, araE, was independently integrated into both strains. Unlike its parental strain, resultant CRA1-araE was able to aerobically grow at low (3.6 g.l(-1)) L-arabinose concentrations. Interestingly, strain CRX2-araE grew 2.9-fold faster than parental CRX2 at low (3.6 g.l(-1)) D-xylose concentrations. The corresponding substrate consumption rates of CRA1-araE and CRX2-araE under oxygen-deprived conditions were 2.8- and 2.7-fold, respectively, higher than those of their respective parental strains. Moreover, CRA1-araE and CRX2-araE utilized their respective substrates simultaneously with D-glucose under both aerobic and oxygen-deprived conditions. Based on these observations, a platform strain, ACX-araE, for C. glutamicum-based mixed sugar utilization was designed. It harbored araBAD for L-arabinose metabolism, xylAB for D-xylose metabolism, D-cellobiose permease-encoding bglF317A, beta-glucosidase-encoding bglA and araE in its chromosomal DNA. In mineral medium containing a sugar mixture of D-glucose, D-xylose, L-arabinose, and D-cellobiose under oxygen-deprived conditions, strain ACX-araE simultaneously and completely consumed all sugars.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerobiosis
  • Anaerobiosis
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism*
  • Corynebacterium glutamicum / genetics*
  • Corynebacterium glutamicum / metabolism*
  • Culture Media / chemistry
  • Genetic Engineering*
  • Hexoses / metabolism
  • Monosaccharide Transport Proteins / genetics*
  • Monosaccharide Transport Proteins / metabolism*
  • Pentoses / metabolism*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism

Substances

  • AraE protein, bacteria
  • Bacterial Proteins
  • Culture Media
  • Hexoses
  • Monosaccharide Transport Proteins
  • Pentoses
  • Recombinant Proteins