Fig. 6

CydC modulates many cellular activities. Proposed role of cydC and ionic liquid tolerance. Proteomic analysis and experimental validation in E. coli deletion strains implicate a suite of pathways involved in the cydC response to [EMIM]OAc. In the top panel, cells express a heterologous gene pathway to produce a desired product, turning sugar (blue hexagon) into the target compound (green hexagon). The addition of the IL [EMIM]OAc in the middle panel has a broad impact on cellular physiology, impacting respiration, inorganic ion response factors, transporters, which ultimately inhibit cell growth and desired production. However, the cydC-D86G mutant in the bottom panel has a distinct proteomic response, and instead upregulates unique gene function categories, such as [U] intracellular trafficking and secretion and [G] carbohydrate metabolism and transport (see Fig. 4 for complete legend), ultimately restoring both cell growth and desired biofuel production