FIG 4 .

Effects of electron transport inhibitors in illuminated sealed tubes with an Ar atmosphere. (a) Incubation with DCMU for 72 h, using 10 ml chemostat cells. Control value (100%) was 3.28 mmol H₂ ⋅ mg Chl⁻¹. (b) Treatment with p-benzoquinone (BQ) for 1 h, at 170 µM. Cells were sampled from a CO₂-deprived bioreactor, 78 h after NH₄⁺ deprivation. Control values (100%, no BQ) were 34 and 346 µmol ⋅ mg Chl⁻¹ ⋅ h⁻¹ for H₂ and O₂, respectively.