1932

Abstract

Adaptation to acid stress is an important factor in the transmission of intestinal microbes. The enterobacterium uses a range of physiological, metabolic, and proton-consuming acid resistance mechanisms in order to survive acid stresses as low as pH 2.0. The physiological adaptations include membrane modifications and outer membrane porins to reduce proton influx and periplasmic and cytoplasmic chaperones to manage the effects of acid damage. The metabolic acid resistance systems couple proton efflux to energy generation via select components of the electron transport chain, including cytochrome oxidase, NADH dehydrogenase I, NADH dehydrogenase II, and succinate dehydrogenase. Under anaerobic conditions the formate hydrogen lyase complex catalyzes conversion of cytoplasmic protons to hydrogen gas. Finally, each major proton-consuming acid resistance system has a pyridoxal-5′-phosphate-dependent amino acid decarboxylase that catalyzes proton-dependent decarboxylation of a substrate amino acid to product and CO, and an inner membrane antiporter that exchanges external substrate for internal product.

Loading

Article metrics loading...

/content/journals/10.1146/annurev-micro-092412-155708
2013-09-08
2024-05-28
Loading full text...

Full text loading...

/content/journals/10.1146/annurev-micro-092412-155708
Loading
/content/journals/10.1146/annurev-micro-092412-155708
Loading

Data & Media loading...

  • Article Type: Review Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error