The present disclosure relates to the use of pantothenate compounds as a non-genetic switch for the production of heterologous acetyl-CoA derived (HACD) compounds in microbial host cells. The invention provides genetically modified microorganisms that are more stable when stored and initially cultured under reduced pantothenate concentrations, cell culture media having reduced concentrations of pantothenate compounds, and methods of producing HACD compounds using the cell culture media and the genetically engineered microorganisms of the invention.