Engineering of acetate recycling and citrate synthase to improve aerobic succinate production in Corynebacterium glutamicum

PLoS One. 2013 Apr 8;8(4):e60659. doi: 10.1371/journal.pone.0060659. Print 2013.

Abstract

Corynebacterium glutamicum lacking the succinate dehydrogenase complex can produce succinate aerobically with acetate representing the major byproduct. Efforts to increase succinate production involved deletion of acetate formation pathways and overexpression of anaplerotic pathways, but acetate formation could not be completely eliminated. To address this issue, we constructed a pathway for recycling wasted carbon in succinate-producing C. glutamicum. The acetyl-CoA synthetase from Bacillus subtilis was heterologously introduced into C. glutamicum for the first time. The engineered strain ZX1 (pEacsA) did not secrete acetate and produced succinate with a yield of 0.50 mol (mol glucose)(-1). Moreover, in order to drive more carbon towards succinate biosynthesis, the native citrate synthase encoded by gltA was overexpressed, leading to strain ZX1 (pEacsAgltA), which showed a 22% increase in succinate yield and a 62% decrease in pyruvate yield compared to strain ZX1 (pEacsA). In fed-batch cultivations, strain ZX1 (pEacsAgltA) produced 241 mM succinate with an average volumetric productivity of 3.55 mM h(-1) and an average yield of 0.63 mol (mol glucose) (-1), making it a promising platform for the aerobic production of succinate at large scale.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / metabolism*
  • Aerobiosis
  • Bacillus subtilis / genetics
  • Batch Cell Culture Techniques
  • Citrate (si)-Synthase / genetics*
  • Citrate (si)-Synthase / metabolism
  • Corynebacterium glutamicum / genetics*
  • Corynebacterium glutamicum / growth & development
  • Corynebacterium glutamicum / metabolism*
  • Genetic Engineering / methods*
  • Pyruvic Acid / metabolism
  • Succinic Acid / metabolism*

Substances

  • Acetates
  • Pyruvic Acid
  • Succinic Acid
  • Citrate (si)-Synthase

Grants and funding

This work was supported by National Program on Key Basic Research Project (2011CBA00804, 2012CB725203), National Natural Science Foundation of China (NSFC-21176182, NSFC-21206112) and National High-tech R&D Program of China (2012AA02A702, 2012AA022103). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.