Methanol production from CO2 with the hybrid system of biocatalyst and organo-photocatalyst

Photochemical and enzymatic production of methanol from CO2 was investigated with the system formate (FDH), aldehyde (AldDH) and alcohol (ADH) dehydrogenases, and methylviologen (MV2+) photoreduction by the visible light photosensitization of organo-photocatalyst, water-soluble porphyrin, tetraphenylporphyrin tetrasulfonate (H2TPPS) in the presence of triethanolamine (TEOA) as an electron donating reagent. To improve the methanol production from CO2, the kinetic parameters for methanol production with ADH and dithionite-reduced MV2+ were clarified. When the sample solution consisting of H2TPPS (100 mu M), MV2+ (2.0 mM), TEOA (0.3 M), FDH (2.0 mu M), AldDH (2.0 mu M) and ADH (2.0 mu M) in CO2 saturated 50 mM sodium pyrophosphate buffer was irradiated, continuous methanol production from CO2 was observed and methanol concentration produced was estimated to be 6.8 mu M after 100 min irradiation.