Article
Extended Data Fig. 9 | Improved growth of Cra-knockout E. coli, and
trade-offs for other microbes. a, Growth rates of the Cra knockout (Δcra) on
glycolytic carbon sources: growth rates on the slow glycolytic sources
(fructose and mannose) are markedly improved compared with the wild type
(WT). The Cra knockout expresses very low levels of most gluconeogenic
enzymes, and glycolytic enzymes are derepressed; hence it cannot grow on
most gluconeogenic carbon sources. b–d, Growth–adaptation tradeoff in
wild-type yeast and B. subtilis. We grew two different wild-type yeast strains
(YPS163 and YPS128) and a B. subtilis strain at different preshift growth rates
(λpre) on different media, before shifting them to acetate (b, c) and fumarate (d)
minimal media. After the shift, culture density (OD 600 ) was monitored as a
function of time. Data points indicate means; error bars show standard
deviations from three biological replicates. The lag time of the growth curves
increases with increasing preshift growth, suggesting a trade-off similar to that
characterized for E. coli (Fig. 1 ). e, Growth comparison for E. coli and B.
thetaiotaomicron, an obligatory anaerobe. The growth rate of E. coli NCM3722
on a number of common carbon substrates from the ‘top’ of central carbon
metabolism (glycolysis and pentosephosphate pathways) exhibit a range of
values, from 0.9 h−1 down to 0.5 h−1 (black bars). The growth rates of B.
thetaiotaomicron (B. theta) on the same substrates in anaerobic conditions (red
bars) are all within 10% of each other. For comparison, we also show the growth
rates of NCM3722 on the same substrates in anaerobic conditions (blue bars).
These show a similar pattern of variation as the aerobic growth rates, with the
fast ones comparable to that of B. thetaiotaomicron (roughly 0.6 h−1) and the
slow ones about one-fifth of the fast ones. Saturating amounts of substrates
(15 mM) were used, except in the case of E. coli on mannose (40 mM).