Fig. 2From: Identification of functional butanol-tolerant genes from Escherichia coli mutants derived from error-prone PCR-based whole-genome shufflingRelative cell densities of strains in the presence of various concentrations of short-chain alcohols. Strains were cultured under different concentrations of iso-butanol (a), ethanol (b) and 1-pentanol (c), and their OD600 was determined. The relative cell density is expressed as a ratio of the biomass value of mutants to that of parallel culture BW25113 under the same culture conditionsBack to article page