Engineering of an L-arabinose metabolic pathway in Corynebacterium glutamicum

Appl Microbiol Biotechnol. 2008 Jan;77(5):1053-62. doi: 10.1007/s00253-007-1244-x. Epub 2007 Oct 27.

Abstract

Corynebacterium glutamicum was metabolically engineered to broaden its substrate utilization range to include the pentose sugar L-arabinose, a product of the degradation of lignocellulosic biomass. The resultant CRA1 recombinant strain expressed the Escherichia coli genes araA, araB, and araD encoding L-arabinose isomerase, L-ribulokinase, and L-ribulose-5-phosphate 4-epimerase, respectively, under the control of a constitutive promoter. Unlike the wild-type strain, CRA1 was able to grow on mineral salts medium containing L-arabinose as the sole carbon and energy source. The three cloned genes were expressed to the same levels whether cells were cultured in the presence of D-glucose or L-arabinose. Under oxygen deprivation and with L-arabinose as the sole carbon and energy source, strain CRA1 carbon flow was redirected to produce up to 40, 37, and 11%, respectively, of the theoretical yields of succinic, lactic, and acetic acids. Using a sugar mixture containing 5% D-glucose and 1% L-arabinose under oxygen deprivation, CRA1 cells metabolized L-arabinose at a constant rate, resulting in combined organic acids yield based on the amount of sugar mixture consumed after D-glucose depletion (83%) that was comparable to that before D-glucose depletion (89%). Strain CRA1 is, therefore, able to utilize L-arabinose as a substrate for organic acid production even in the presence of D-glucose.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetic Acid / metabolism
  • Anaerobiosis
  • Arabinose / metabolism*
  • Carbon / metabolism
  • Carboxylic Acids / metabolism
  • Corynebacterium glutamicum / genetics*
  • Corynebacterium glutamicum / growth & development
  • Corynebacterium glutamicum / metabolism*
  • Culture Media / chemistry
  • Energy Metabolism
  • Escherichia coli / enzymology
  • Escherichia coli / genetics
  • Escherichia coli Proteins / biosynthesis
  • Escherichia coli Proteins / genetics
  • Gene Expression
  • Glucose / metabolism
  • Lactic Acid / metabolism
  • Metabolic Networks and Pathways*
  • Phosphotransferases (Alcohol Group Acceptor) / biosynthesis
  • Phosphotransferases (Alcohol Group Acceptor) / genetics
  • Succinic Acid / metabolism

Substances

  • Carboxylic Acids
  • Culture Media
  • Escherichia coli Proteins
  • Lactic Acid
  • Carbon
  • Succinic Acid
  • Arabinose
  • Phosphotransferases (Alcohol Group Acceptor)
  • ribulokinase
  • Glucose
  • Acetic Acid