Figure 2.

Increased fluxes through the physiological pathways used for H₂ production in Chlamydomonas under dark condition. Acetate is assimilated (red arrows) and starch is produced through gluconeogenic conversion. Green arrows highlight increased fluxes through acetate metabolism, starch synthesis/degradation and the physiological pathways for H₂ production in Chlamydomonas. The blue arrows are the increased fluxes through enzymes involved in H₂ synthesis. Numbers represent the main enzymatic and transport reactions: (1) acetate assimilation; (2,4) acetate transporter; (3,5) acetyl-Coa synthetase; (6,7) succinate transporter; (8) phosphoenolpyruvate carboxykinase; (9) phosphoglucomutase (10) 1,4-alpha-glucan branching enzyme; (11) glyceraldehyde 3-phosphate dehydrogenase; (12) pyruvate kinase; (13) pyruvate ferredoxin oxidoreductase (PFR1); (14) ferredoxin hydrogenase. GLU: glucose; PEP: Phosphoenolpyruvate; G6P: glucose 6-phosphate; SUCC: Succinatate; MAL: malate; CIT: citrate; OAA: oxaloacetate; FDX red: reduced ferredoxin; FDX ox: oxidized ferredoxin.