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bioRxiv · 10.1101/113183

A yield-cost tradeoff governs Escherichia coli's decision between fermentation and respiration in carbon-limited growth

Mori, M.·Marinari, E.·De Martino, A.
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Abstract

Many microbial systems are known to actively reshape their proteomes in response to changes in growth conditions induced e.g. by nutritional stress or antibiotics. Part of the re-allocation accounts for the fact that, as the growth rate is limited by targeting specific metabolic activities, cells simply respond by fine-tuning their proteome to invest more resources into the limiting activity (i.e. by synthesizing more proteins devoted to it). However, this is often accompanied by an overall re-organization of metabolism, aimed at improving the growth yield under limitation by re-wiring resource through different pathways. While both effects impact proteome composition, the latter underlies a more complex systemic response to stress. By focusing on E. coli's acetate switch, we use mathematical modeling and a re-analysis of empirical data to show that the transition from a predominantly fermentative to a predominantly respirative metabolism in carbon-limited growth results from the trade-off between maximizing the growth yield and minimizing its costs in terms of required the proteome share. In particular, E. coli's metabolic phenotypes appear to be Pareto-optimal for these objective functions over a broad range of dilutions.

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Mori, M., Marinari, E., De Martino, A.. 2017-03-02. A yield-cost tradeoff governs Escherichia coli's decision between fermentation and respiration in carbon-limited growth. https://doi.org/10.1101/113183

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