Provided are systems and methods for accurately determining flux distribution in organisms or cells without use of metabolic flux analysis data. The methods include estimating flux distributions in multiple reference strains (variants of a parental strain) using experimentally determined extracellular flux data from the reference strains, and determining a flux distribution for the parental strain from the estimated flux distributions for the reference strains and from experimentally measured extracellular fluxes for the parental strain. The systems are configured for carrying out the methods.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
 This invention was made with government support under DE-SC0008103 awarded by the US Department of Energy. The government has certain rights in the invention.