Fig. 4
The effect of an iron-salt-based O2 absorbent (O20TM) on the H2 production of Chlamydomonas in acetate-free HS medium induced by dark anaerobic incubation. a Photograph of the H2-producing Chlamydomonas cultures in serum bottles with the iron-salt-based O2 absorbent introduced into the headspace. b, c The effects of the iron-salt-based O2 absorbent on the daily H2 production and daily O2 accumulation in Chlamydomonas cultures illuminated continuously at 320 µmol photons/m2/s. The cultures were flushed with N2 for 10 min every 24 h after determining the gas concentrations in the headspaces of the sealed bottles. Mean values (± SEM) are each based on 11–15 biological replicates. Statistical significance levels are presented relative to the Chlamydomonas culture subjected to dark anaerobic incubation in HS medium as *p < 0.05; ***p < 0.001