The damaging effects of short chain fatty acids on Escherichia coli membranes
Open Access
- 3 August 2013
- journal article
- applied microbial-and-cell-physiology
- Published by Springer Science and Business Media LLC in Applied Microbiology and Biotechnology
- Vol. 97 (18), 8317-8327
- https://doi.org/10.1007/s00253-013-5113-5
Abstract
Carboxylic acids are an attractive biorenewable chemical. However, like many other fermentatively produced compounds, they are inhibitory to the biocatalyst. An understanding of the mechanism of toxicity can aid in mitigating this problem. Here, we show that hexanoic and octanoic acids are completely inhibitory to Escherichia coli MG1655 in minimal medium at a concentration of 40 mM, while decanoic acid was inhibitory at 20 mM. This growth inhibition is pH-dependent and is accompanied by a significant change in the fluorescence polarization (fluidity) and integrity. This inhibition and sensitivity to membrane fluidization, but not to damage of membrane integrity, can be at least partially mitigated during short-term adaptation to octanoic acid. This short-term adaptation was accompanied by a change in membrane lipid composition and a decrease in cell surface hydrophobicity. Specifically, the saturated/unsaturated lipid ratio decreased and the average lipid length increased. A fatty acid-producing strain exhibited an increase in membrane leakage as the product titer increased, but no change in membrane fluidity. These results highlight the importance of the cell membrane as a target for future metabolic engineering efforts for enabling resistance and tolerance of desirable biorenewable compounds, such as carboxylic acids. Knowledge of these effects can help in the engineering of robust biocatalysts for biorenewable chemicals production.Keywords
This publication has 55 references indexed in Scilit:
- LPS remodeling is an evolved survival strategy for bacteriaProceedings of the National Academy of Sciences of the United States of America, 2012
- Antimicrobial Mechanism of MonocaprylateApplied and Environmental Microbiology, 2012
- Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coliApplied and Environmental Microbiology, 2011
- Perspective on opportunities in industrial biotechnology in renewable chemicalsBiotechnology Journal, 2011
- Role of Alcohols in Growth, Lipid Composition, and Membrane Fluidity of Yeasts, Bacteria, and ArchaeaApplied and Environmental Microbiology, 2011
- Outer membrane permeability and antibiotic resistanceBiochimica et Biophysica Acta (BBA) - Proteins and Proteomics, 2009
- An integrated network approach identifies the isobutanol response network of Escherichia coliMolecular Systems Biology, 2009
- Lipid A Modification Systems in Gram-Negative BacteriaAnnual Review of Biochemistry, 2007
- YcfR (BhsA) InfluencesEscherichia coliBiofilm Formation through Stress Response and Surface HydrophobicityJournal of Bacteriology, 2007
- A RAPID METHOD OF TOTAL LIPID EXTRACTION AND PURIFICATIONCanadian Journal of Biochemistry and Physiology, 1959