Hydrogen Gas Production on Reversible Inactivation of O2 Evolution in Chlamydomonas reinhardtii

You are at: Oilgae Blog. See the complete list of Oilgae Blog articles.

Do you know that oil derived from algae is an exciting renewable fuel possibility? - see Oilgae for more.

Sustained Photobiological Hydrogen Gas Production upon Reversible Inactivation of Oxygen Evolution in the Green Alga Chlamydomonas reinhardtii

From Plant Physiol, Jan 2000

1 Anastasios Melis,* Liping Zhang, Marc Forestier, Maria L. Ghirardi, and Michael Seibert
Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, Berkeley, California 94720-3102 (A.M., L.Z.); and Basic Sciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401-3393 (M.F., M.L.G., M.S.).

The work describes a novel approach for sustained photobiological production of H2 gas via the reversible hydrogenase pathway in the green alga Chlamydomonas reinhardtii. This single-organism, two-stage H2 production method circumvents the severe O2 sensitivity of the reversible hydrogenase by temporally separating photosynthetic O2 evolution and carbon accumulation (stage 1) from the consumption of cellular metabolites and concomitant H2 production (stage 2). A transition from stage 1 to stage 2 was effected upon S deprivation of the culture, which reversibly inactivated photosystem II (PSII) and O2 evolution. Under these conditions, oxidative respiration by the cells in the light depleted O2 and caused anaerobiosis in the culture, which was necessary and sufficient for the induction of the reversible hydrogenase. Subsequently, sustained cellular H2 gas production was observed in the light but not in the dark. The mechanism of H2 production entailed protein consumption and electron transport from endogenous substrate to the cytochrome b6-f and PSI complexes in the chloroplast thylakoids. Light absorption by PSI was required for H2 evolution, suggesting that photoreduction of ferredoxin is followed by electron donation to the reversible hydrogenase. The latter catalyzes the reduction of protons to molecular H2 in the chloroplast stroma.

Original source and link for the full PDF report here

Nature gave us oil from algae; perhaps we should try Nature's way again

Oilgae - Oil & Biodiesel from Algae
Oilgae Blog; The complete list of Oilgae Blog articles.
algOS - Biodiesel from Algae Open Source

About Oilgae - Oilgae - Oil & Biodiesel from Algae has a focus on biodiesel production from algae while also discussing alternative energy in general. Algae present an exciting possibility as a feedstock for biodiesel, and when you realise that oil was originally formed from algae - among other related plants - you think "Hey! Why not oil again from algae!"