The effect of metabolic stress on genome stability of a synthetic biology chassis Escherichia coli K12 strain

Couto, J. M., McGarrity, A., Russell, J. and Sloan, W. T. (2018) The effect of metabolic stress on genome stability of a synthetic biology chassis Escherichia coli K12 strain. Microbial Cell Factories, 17, 8. (doi: 10.1186/s12934-018-0858-2) (PMID:29357936) (PMCID:PMC5776760)

140882.pdf - Published Version
Available under License Creative Commons Attribution.



Background: Synthetic organism-based biotechnologies are increasingly being proposed for environmental applications, such as in situ sensing. Typically, the novel function of these organisms is delivered by compiling genetic fragments in the genome of a chassis organism. To behave predictably, these chassis are designed with reduced genomes that minimize biological complexity. However, in these proposed applications it is expected that even when contained within a device, organisms will be exposed to fuctuating, often stressful, conditions and it is not clear whether their genomes will retain stability. Results: Here we employed a chemostat design which enabled us to maintained two strains of E. coli K12 under sustained starvation stress: frst the reduced genome synthetic biology chassis MDS42 and then, the control parent strain MG1655. We estimated mutation rates and utilised them as indicators of an increase in genome instability. We show that within 24 h the spontaneous mutation rate had increased similarly in both strains, destabilizing the genomes. High rates were maintained for the duration of the experiment. Growth rates of a cohort of randomly sampled mutants from both strains were utilized as a proxy for emerging phenotypic, and by association genetic variation. Mutant growth rates were consistently less than rates in non-mutants, an indicator of reduced ftness and the presence of mildly deleterious mutations in both the strains. In addition, the efect of these mutations on the populations as a whole varied by strain. Conclusions: Overall, this study shows that genome reductions in the MDS42 did not stabilize the chassis under metabolic stress. Over time, this could compromise the efectiveness of synthetic organisms built on chassis in environmental applications.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Sloan, Professor William and Russell, Mrs Julie and McGarrity, Ms Anne and Couto, Dr Jillian
Authors: Couto, J. M., McGarrity, A., Russell, J., and Sloan, W. T.
College/School:College of Science and Engineering > School of Engineering
College of Science and Engineering > School of Engineering > Infrastructure and Environment
Journal Name:Microbial Cell Factories
Publisher:BioMed Central
ISSN (Online):1475-2859
Copyright Holders:Copyright © 2018 The Authors
First Published:First published in Microbial Cell Factories 17: 8
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
621351Synthetic Biology applications to Water Supply and RemediationSteven BeaumontEngineering and Physical Sciences Research Council (EPSRC)EP/K038885/1VPO VICE PRINCIPAL RESEARCH & ENTERPRISE