Campus Units

Chemical and Biological Engineering, NSF Engineering Research Center for Biorenewable Chemicals

Document Type

Article

Research Focus Area

Biorenewables

Publication Version

Published Version

Publication Date

10-2018

Journal or Book Title

Applied and Environmental Microbiology

Volume

84

Issue

19

First Page

e01285-18

DOI

10.1128/AEM.01285-18

Abstract

Fermentative production of many attractive biorenewable fuels and chemicals is limited by product toxicity in the form of damage to the microbial cell membrane. Metabolic engineering of the production organism can help mitigate this problem, but there is a need for identification and prioritization of the most effective engineering targets. Here, we use a set of previously characterized environmental Escherichia coli isolates with high tolerance and production of octanoic acid, a model membrane-damaging biorenewable product, as a case study for identifying and prioritizing membrane engineering strategies. This characterization identified differences in the membrane lipid composition, fluidity, integrity, and cell surface hydrophobicity from those of the lab strain MG1655. Consistent with previous publications, decreased membrane fluidity was associated with increased fatty acid production ability. Maintenance of high membrane integrity or longer membrane lipids seemed to be of less importance than fluidity. Cell surface hydrophobicity was also directly associated with fatty acid production titers, with the strength of this association demonstrated by plasmid-based expression of the multiple stress resistance outer membrane protein BhsA. This expression of bhsA was effective in altering hydrophobicity, but the direction and magnitude of the change differed between strains. Thus, additional strategies are needed to reliably engineer cell surface hydrophobicity. This work demonstrates the ability of environmental microbiological studies to impact the metabolic engineering design-build-test-learn cycle and possibly increase the economic viability of fermentative bioprocesses.

Comments

This article is published as Chen, Yingxi, Michael Reinhardt, Natalia Neris, Lucas Kerns, Thomas J. Mansell, and Laura R. Jarboe. "Lessons in Membrane Engineering for Octanoic Acid Production from Environmental Escherichia coli Isolates." Applied and Environmental Microbiology 84, no. 19 (2018): e01285-18. DOI: 10.1128/AEM.01285-18. Posted with permission.

Copyright Owner

American Society for Microbiology

Language

en

File Format

application/pdf

Available for download on Sunday, January 20, 2019

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