Study Of The Process Characterizations Of H₂ Photoproduction From Platymonas Subcordiformis At High Cell Density

A marine green microalga, Platymonas subcordiformis, was demonstrated to photosynthetically generate H₂ from sea water lately. Compared with the Chlamydomonas reinhardtii, a fresh-water green alga, which was most-often-used in the study of biohydrogen production at present, the yield of H2 production from P. subcordiformis was low and the duration of H2 production was short. So the study on the regulation and optimization of the H2 production protocol is an approach to promote the H2 production efficiency. In this paper, the key process variables of H2 production from P. subcordiformis were optimized and the limited factors in the process were studied to prolong the duration of the H2 production and increase the efficiency.In this paper, the effect of cell density on H2 production from P. subcordiformis was studied. It was founded that the H2 production was significantly affected by the cell density. The higher the cell density is, the higher the H2 production rate and the longer the duration of H2 production is. Besides, the H2 productivity of each cell doesn't decrease. The optimal cell density for the H2 production was around 6-8×10⁶ cells/ml. In addition, P. subcordiformis could produce hydrogen repeatedly for five times, the efficiency of each time was a bit lower than the original one. Based on the H₂ production at high cell density, the effect of H2 gas pressure in the system on H₂ production was further studied. Hydrogen inhibition effect was founded in the process of H2 production from P. subcordiformis when...