Unicellular green algae have the ability to operate in two distinctly different environments (aerobic and anaerobic) and to photosynthetically generate molecular hydrogen (H2). A recently developed metabolic protocol permitted separation of photosynthetic O2 evolution and carbon accumulation from anaerobic consumption of cellular metabolites and concomitant photosynthetic H2 evolution in the light. The H2-evolving metabolic process was induced upon sulfate nutrient deprivation of the algae, which reversibly inhibits photosystem-II and O2-evolution in their chloroplast. In the absence of O2, and in order to generate ATP, green algae resorted to anaerobic photosynthetic metabolism, evolved H2 gas in the light and consumed endogenous substrate. Hydrogen generation in green algae draws attention to an alternative cellular metabolism and offers a new avenue of research in photosynthesis.

The main objectives of the proposal are:

  1. A thorough investigation of the growth conditions of wild type and mutants of Scenedesmus obliquus and Chlamydomonas reinhardtii that lead to maximal production of hydrogen,
  2. characterization of the photosynthetic activity of the various mutants by biochemical and spectroscopic techniques,
  3. immobilization/stabilization of chlamydomonas in cheap biocompatible materials,
  4. proteomic analysis in order to associate protein differentiation with the hydrogenase activity, and
  5. the development of a prototype bioreactor.

Three Greek groups with different but complementary expertise will be involved in this proposal. The substantial participation of Prof. Melis, who is one of the pioneers in biohydrogen research, will lead to the development of a Greek consortium actively involved in the area of biohydrogen production by green algae. The construction of a lab scale algal photobioreactor and the development of a techno-economic evaluation model would allow us to explore the possibilities of industrial applications.


ALGAH2 / MIS: 377283

Project info

Coordinating Institution:
University of Crete
Scientific Coordinator:
Ghanotakis Demetrios
Research Team 1 Leader:
Ghanotakis Demetrios
Research Team 2 Leader:
Kotzabasis Kyriakos
Research Team 3 Leader:
Petrouleas Vassili


600 000.00

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