We are working on genetically characterizing the fast-growing cyanobacterium Synechococcus UTEX 2973. This strain has the fastest doubling time of any known species of cyanobacteria and the highest rate of biomass production observed in cyanobacteria, making it a prime target for biofuel production. Interestingly, this strain only differs from the slower growing model organism Synechococcus elongatus PCC7942 by 55 single nucleotide changes. We are applying CRISPR genome editing technology to elucidate which mutations are responsible of the fast growth phenotype. We are also examining photosynthetic and physiological differences between the newly discovered strain and slow-growing model strain. With knowledge gained from this study, we will be able to introduce similar modifications into the genomes of other cyanobacteria to improve their overall productivity.