Fig. 2From: Gene modification of Escherichia coli and incorporation of process control to decrease acetate accumulation and increase ʟ-tryptophan productionEffect of genetic modification on the accumulation of byproducts during ʟ-tryptophan production. Squares BCTRP, circles BCTRPP, upright triangles BCTRPG, and inverse triangles BCTRPPG. The absolute value of the data in b less than zero indicates the consumption rate of acetate (P < 0.05)Back to article page