Fig. 7

Growth and lycopene levels of KTLYC cells producing either DXS or nDXS. The strains KTLYC(p424), KTLYC(p424-DXS) and KLYC(p424-nDXS) were cultured in the indicated mediums: LB, LB supplemented with 50 mM glucose, or M9 minimal salt medium containing 50 mM glucose, 30 mM citrate or 30 mM succinate as carbon source. Expression of genes encoding DXS or nDXS was induced with 1 mM IPTG 1 h after inoculation. After 24 h, growth was estimated as optical density at 600 nm (OD₆₀₀) (upper graph) and lycopene accumulation was calculated by measuring the absorbance at 472 nm of acetone extracts of the cells and normalized to cell density (lower graph). Values shown are the mean ± SD of three independent assays. Asterisks indicate statistically significant differences (T-test, P-value < 0.05 * or 0.01 **) relative to KTLYC(p424) controls