Cell growth, glycerol utilization, and lactate synthesis in 36-hour shake flasks cultures of wild-type MG1655 and engineered strains. (A) LA01 (ΔpflB Δfrd A), LA02 (Δpta ΔadhE ΔfrdA), LA06 (ΔpflB ΔfrdA ΔldhA) and LA07 (Δpta ΔadhE ΔfrdA ΔldhA). (B) LA06 (pZSblank), LA07 (pZSblank), LA06 (pZSldh), LA07 (pZSldh), LA19 (ΔpflB ΔfrdA ΔmgsA ΔldhAldh+), and LA20 (Δpta ΔadhE ΔfrdA ΔmgsA ΔldhAldh+). Gene expressions from either plasmid or chromosomal integration are indicated by a “+” next to the corresponding gene(s) or operon(s). Error bars represent standard deviations for triplicate measurements.