Hydrogen is considered to be the most promising energy for the future. Nowadays in industry it is
produced by a thermo-chemical transformation of fossil fuels or by electrolysis of water [1],
however it can be produced by various kinds of microorganisms such as microalgae,
photosynthetic bacteria, cyanobacteria and other bacteria. Among these organisms hydrogen
metabolism of photosynthetic eukaryotic algae has been intensively studied. It was firstly reported
in the 1940s that the green alga Scenedesmus obliquus can use hydrogen as an electron donor to
fix CO2 under anaerobic condition in the dark [2-3]. S. obliquus in particular can utilize the energy
of sunlight in photosynthesis to produce hydrogen [4]. Besides this strain, hydrogen evolution has
been also investigated in other kinds of green algae such as Chlamydomonas reinhardtii [5-6] and
Chlorella vulgaris [7]. One of the advantages of green algae for producing hydrogen is their
ability to grow under photoautotrophic and photoheterotrophic condition [8]. In this study the
green alga dominating a natural pond was isolated to study the hydrogen production under the