Fig. 4From: Identification of functional butanol-tolerant genes from Escherichia coli mutants derived from error-prone PCR-based whole-genome shufflingGrowth evaluation of acrB and rob overexpression strains. Serial acrB (a) and rob (b) gene overexpression strains were cultured in LB media with (b, d) and without butanol (a, c). The initial concentration of inoculation was controlled at OD600 = 0.2, and 0.02% (w/v) of L-arabinose was added to the media to induce the expression of the target geneBack to article page