+, ferredoxin _ NADP +_ reductase (FNR) and ME. Malic acid production was 2.0 mmol dmafter 3-h irradiation under the optimum conditions with NADH, ZnChl-e6, MV 2+ , FNR, pyruvic acid, NaHCO3, NADP + and ME. The ratio of HCO3 − and pyruvic acid to malic acid was about 20 under the optimum conditions.