Effect of Plasmid Addition on the Production of 1-Butanol from CO2 in Isolated S.Elongatus from the Sea Sediment of Konak - Izmir

For a sustainable future it is essential to close the global carbon cycle. Oxidised forms of carbon, in particular CO2, can be used to synthesise energy-rich organic molecules. Engineered cyanobacteria have attracted attention as catalysts for the direct conversion of CO2 into reduced fuel compounds.1-Butanol is a promising gasoline replacement compared to the more commonly used ethanol due to several advantages. Specifically, 1-butanol is less corrosive and has a higher energy density than ethanol. In this study, Synechococcus elongatus was isolated from the sea sediment in Konak and the effects of CO2 isolated from the same region on the production of 1-butanol was investigated. Addition of plasmid slightly increased the CO2 utilisation rates. The effects of environmental factors (NO3-N, SO4-S, NaCl, H2, O2) on the ratio of 1-butanol production to CO2 removal were investigated. Under optimized conditions S.elongatus metabolized theCO2 according to Monod kinetic(Ks = 1.5 mg L-1 and µ = 0.21 day-1 ). Under highNO3-N, SO4-S, NaCl, and O2 concentrations 1-butanol produced with un-competitive inhibition with a high Ki value of 2.3 mg L-1 indicating the low inhibition in S.elongatus with plasmid. The competitive inhibition constant (Ki) is low (0.70 mg L-1 ) exhibiting the high competitive inhibition at high concentration for the operational conditions given above