The polyhydroxyalkanoate metabolism controls carbon and energy spillage in Pseudomonas putida
Article first published online: 9 JAN 2012
© 2012 Society for Applied Microbiology and Blackwell Publishing Ltd
Volume 14, Issue 4, pages 1049–1063, April 2012
How to Cite
Escapa, I. F., García, J. L., Bühler, B., Blank, L. M. and Prieto, M. A. (2012), The polyhydroxyalkanoate metabolism controls carbon and energy spillage in Pseudomonas putida. Environmental Microbiology, 14: 1049–1063. doi: 10.1111/j.1462-2920.2011.02684.x
- Issue published online: 4 APR 2012
- Article first published online: 9 JAN 2012
- Received 2 July, 2011; revised 22 November, 2011; accepted 25 November, 2011.
The synthesis and degradation of polyhydroxyalkanoates (PHAs), the storage polymer of many bacteria, is linked to the operation of central carbon metabolism. To rationalize the impact of PHA accumulation on central carbon metabolism of the prototype bacterium Pseudomonas putida, we have revisited PHA production in quantitative physiology experiments in the wild-type strain vs. a PHA negative mutant growing under low nitrogen conditions. When octanoic acid was used as PHA precursor and as carbon and energy source, we have detected higher intracellular flux via acetyl-CoA in the mutant strain than in the wild type, which correlates with the stimulation of the TCA cycle and glyoxylate shunt observed on the transcriptional level. The mutant defective in carbon and energy storage spills the additional resources, releasing CO2 instead of generating biomass. Hence, P. putida operates the metabolic network to optimally exploit available resources and channels excess carbon and energy to storage via PHA, without compromising growth. These findings demonstrate that the PHA metabolism plays a critical role in synchronizing global metabolism to availability of resources in PHA-producing microorganisms.