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Fig. 1 | Microbial Cell Factories

Fig. 1

From: Restoration of biofuel production levels and increased tolerance under ionic liquid stress is enabled by a mutation in the essential Escherichia coli gene cydC

Fig. 1

Adaptation and Laboratory Evolution of E. coli DH1 in presence of [EMIM]OAc. a Exponential phase E. coli cells were grown in the presence of 100 mM [EMIM]OAc at 30 °C in a microtiter dish until a change in optical density was detected (“Methods”). Red circles, growth of wild-type cells in the absence of [EMIM]OAc. Black squares, growth of wild-type cells in the presence of [EMIM]OAc. Standard deviation from three biological replicates is indicated as the shaded region surrounding the red circles or black squares. Optical density is plotted on a log10 scale. b Schematic, behavior of cells after gaining a heritable mutation (top panel) compared to adaptation (bottom panel). Cells initially grown in the absence of the ionic liquid stress (“EZ”) are back-diluted into medium containing the ionic liquid (“EZ + IL”). After a long lag phase, an increase in optical density is detected. Cells are subsequently back diluted into fresh media without the ionic liquid (“EZ”) and then retested for growth in the presence of the ionic liquid (“EZ + IL”). A heritable mutation would prevent the appearance of an extended lag phase after the first exposure to an ionic liquid. If E. coli adapts to the IL, cells would show a similarly long lag phase as with the first treatment with ionic liquid. c Cells exhibit a heritable response to [EMIM]OAc. All three independent isolates show similar tolerance to [EMIM]OAc. Error bars indicate standard deviation from three biological replicates

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