Campus Units

Chemical and Biological Engineering, Bioinformatics and Computational Biology, Microbiology, Toxicology

Document Type

Article

Research Focus Area

Biorenewables

Publication Version

Published Version

Publication Date

9-2013

Journal or Book Title

Applied Microbiology and Biotechnology

Volume

97

Issue

18

First Page

8317

Last Page

8327

DOI

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.

Comments

This article is published as Royce, Liam A., Ping Liu, Matthew J. Stebbins, Benjamin C. Hanson, and Laura R. Jarboe. "The damaging effects of short chain fatty acids on Escherichia coli membranes." Applied Microbiology and Biotechnology 97, no. 18 (2013): 8317-8327. DOI: 10.1007/s00253-013-5113-5. Posted with permission.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Copyright Owner

The Authors

Language

en

File Format

application/pdf

Share

COinS