For CRBF adaptation and strain verification in synthetic media, biomass, glucose and ethanol concentrations were estimated spectrophotometrically using a 96-well microplate reader (Biotech Synergy HT). Biomass samples (20 mL in bioreactor, 1 mL flasks) were taken with a micropipette equipped with a large-opened cut tip, and then deflocculated by stirring vigorously with the addition of EDTA 75 mM at 1:1 volume. Then, the cell suspension was diluted with tap water, and the absorbance at 620 nm was determined. The biomass concentration was calculated through a dry mass calibration curve obtained from cells cultivated in liquid culture as previously described (Section 2.1). Glucose concentration was determined by the DNS method [24], and the ethanol concentration by using an enzymatic kit (Boehringer Ethanol Test Kit, R-Biopharm). Both methods were adapted for use in 96-well microplates (final volume 0.3 mL). All samples were analyzed in duplicates.