Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7724360 | International Journal of Hydrogen Energy | 2011 | 5 Pages |
Abstract
Photoproduction of H2 gas was examined in the Chlamydomonas reinhardtii tla1 strain, CC-4169, containing a truncated light-harvesting antenna, along with its parental CC-425 strain. Although enhanced photosynthetic performance of truncated antenna algae has been demonstrated previously (Polle et al. Planta 2003; 217:49-59), improved H2 photoproduction has yet to be reported. Preliminary experiments showed that sulfur-deprived, suspension cultures of the tla1 mutant could not establish anaerobiosis in a photobioreactor, and thus, could not photoproduce H2 gas under conditions typical for the sulfur-deprived wild-type cells (Kosourov et al. Biotech Bioeng 2002; 78:731-40). However, they did produce H2 gas when deprived of sulfur and phosphorus after immobilization within thin (â¼300 μm) alginate films. These films were monitored for long-term H2 photoproduction activity under light intensities ranging from 19 to 350 μE mâ2 sâ1 PAR. Both the tla1 mutant and the CC-425 parental strain produced H2 gas for over 250 h under all light conditions tested. Relative to the parental strain, the CC-4169 mutant had lower maximum specific rates of H2 production at low and medium light intensities (19 and 184 μE mâ2 sâ1), but it exhibited a 4-times higher maximum specific rate at 285 μE mâ2 sâ1 and an 8.5-times higher rate at 350 μE mâ2 sâ1 when immobilized at approximately the same cell density as the parental strain. As a result, the CC-4169 strain accumulated almost 4-times more H2 than CC-425 at 285 μE mâ2 sâ1 and over 6-times more at 350 μE mâ2 sâ1 during 250-h experiments. These results are the first demonstration that truncating light-harvesting antennae in algal cells can increase the efficiency of H2 photoproduction in mass culture at high light intensity.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Sergey N. Kosourov, Maria L. Ghirardi, Michael Seibert,