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%26lt;list list-type=%26quot;bulleted%26quot; id=%26quot;nph12964-list-0001%26quot;%26gt; In anaerobiosis, the microalga Chlamydomonas reinhardtii is able to produce H-2 gas. Electrons mainly derive from mobilization of internal reserves or from water through biophotolysis. However, the exact mechanisms triggering this process are still unclear. Our hypothesis was that, once a proper redox state has been achieved, H-2 production is eventually observed. To avoid nutrient depletion, which would result in enhanced fermentative pathways, we aimed to induce long-lasting H-2 production solely through a photosynthesis:respiration equilibrium. Thus, growing cells were incubated in Tris Acetate Phosphate (TAP) medium under low light and high chlorophyll content. After a 250-h acclimation phase, a 350-h H-2 production phase was observed. The light-to-H-2 conversion efficiency was comparable to that given in some reports operating under sulphur starvation. Electron sources were found to be water, through biophotolysis, and proteins, particularly through photofermentation. Nonetheless, a substantial contribution from acetate could not be ruled out. In addition, photosystem II (PSII) inhibition by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) showed that it actively contributed to maintaining a redox balance during cell acclimation. In appropriate conditions, PSII may represent the major source of reducing power to feed the H-2 evolution process, by inducing and maintaining an ideal excess of reducing power. %26lt;doi origin=%26quot;wiley%26quot; registered=%26quot;yes%26quot;%26gt;10.1111/(ISSN)1469-8137%26lt;/doi
- 出版日期2014-12
