Figure 3.

Assay of osmoregulation capacity in PYG or M9 medium with/without glycine betaine. The OD₆₀₀ values of engineered E. coli strains were measured for cells cultured in PYG or M9 medium with 1% n-butanol (vol/vol) at 37°C. The M9 minimal medium is a simple growth medium containing 1% glucose, sodium chloride and phosphate salt; the compatible solute, GB, was added at 10 mM concentration for evaluation of osmoregulation capacity. The relative growth rates were compared with the strain controls cultured in PYG medium without alcohols.