Many different groups of microorganisms have the ability to produce hydrogen, and all naturally occurring hydrogen producing organisms contain one or several hydrogenase enzymes. Many green algae have the ability to produce hydrogen, but the genes encoding the hydrogenases have thus far only been examined in very few species (1). It is known that Chlamydomonas reinhardtii has the capability to produce significant amounts of hydrogen during sulfur-deprivation, but only limited information is available about this process in other species. C.reinhardtii has been shown to contain two hydrogenases, encoded by hydA1 and hydA2, and it appears likely that other species of green algae also have more than one hydrogenase. In the present work, species of green algae were selected for their capability to produce hydrogen during sulfur deprivation (2), and the genes encoding the hydrogenases were identified and characterized. Probes constructed from fragments of hydA1 in C.reinhardtii which showed sequence homology with all the known species of green algae were used to screen for the presence of similar sequences in other species, by Southern Blot hybridizations. Degenerated primers were designed from conserved regions in known species of green algae, and 3’-RACE and 5’-RACE were performed using RNA isolated from hydrogen producing cultures of the selected species. The fragments of amplified cDNA were cloned and sequenced, and the study will compare and contrast obtained hydA mRNA sequences and address the diversity of hydA genes in green algae.

(1) K.Skjånes,P.Lindblad,J.Muller. Biomol.Eng. 24:405-413,2007
(2) K.Skjånes,G.Knutsen,T.Källqvist,P.Lindblad. Int.J.Hydrogen Energy 2007, Published online (doi:10.1016/j.ijhydene.2007.09.040)