Using recombinant strains of Synechocastis and engineering the expression of hoxH and other hydrogenase genes, the researchers succeeded to increase the production of succinic and lactic acid from CO2 under anaerobic conditions in the dark 5- and 13-fold, reaching levels of 100 and 300 mg/l, respectively. Hydrogen production was reduced by 20 %, indicating a competition of hydrogen and acid formation for reducing power.

China Bio news release, July 26, 2016