Fig. 5From: Gene modification of Escherichia coli and incorporation of process control to decrease acetate accumulation and increase ʟ-tryptophan productionʟ-Tryptophan production in a fermentation with a DO level of 30%, glucose feedback feeding, and sequential pH adjustments. Filled squares accumulation of acetate, filled circles biomass, and open circles ʟ-tryptophan levels (P < 0.05)Back to article page