Use of photoautotrophic organism for direct conversion of CO2 into useable chemicals are gaining importance. Cyanobacteria, a photoautotrophic organism, have the ability to harvest light energy to produce important chemicals. My study focuses on using Isotopically nonstationary 13C MFA (INST-MFA) to estimate the intracellular fluxes in the wild-type strain and mutant cyanobacterial strain and using pathway fluxes to identify bottlenecks in the production pathway and use it to guide rational metabolic engineering to improve strain performance in recombinant strains