Role of glutamate metabolism in bacterial responses towards acid and other stresses

J Appl Microbiol. 2013 Jan;114(1):11-24. doi: 10.1111/j.1365-2672.2012.05434.x. Epub 2012 Sep 27.


Glutamate plays a central role in a wide range of metabolic processes in bacterial cells. This review focuses on the involvement of glutamate in bacterial stress responses. In particular, it reviews the role of glutamate metabolism in response against acid stress and other stresses. The glutamate decarboxylase (GAD) system has been implicated in acid tolerance in several bacterial genera. This system facilitates intracellular pH homoeostasis by consuming protons in a decarboxylation reaction that produces γ-aminobutyrate (GABA) from glutamate. An antiporter system is usually present to couple the uptake of glutamate to the efflux of GABA. Recent insights into the functioning of this system will be discussed. Finally, the intracellular fate of GABA will also be discussed. Many bacteria are capable of metabolizing GABA to succinate via the GABA shunt pathway. The role and regulation of this pathway will be addressed in the review.

Publication types

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

MeSH terms

  • Acids / metabolism*
  • Antiporters / metabolism
  • Bacteria / metabolism*
  • Glutamate Decarboxylase / metabolism*
  • Glutamic Acid / metabolism*
  • Stress, Physiological
  • Succinic Acid / metabolism
  • gamma-Aminobutyric Acid / metabolism


  • Acids
  • Antiporters
  • Glutamic Acid
  • gamma-Aminobutyric Acid
  • Succinic Acid
  • Glutamate Decarboxylase