Comparative Characterization Of Photobiological Hydrogen Production Between Marine And Freshwater Green Algae

In this paper, systemically researched the characterization and mechanism of marine green algae Platymonas subcordiformis hydrogen photoproduction under stress condition such as addition PSII inhibitor DCMU, sulfur-deprived, and treated with uncoupler CCCP, freshwater green algae Chlamydomonas reinhardtii cc124 was taken as contrast sample, to obtain the suitable method of regulation hydrogen photoproduction.DCMU can markedly inhibit the PSII photochemical activity, and hold the suspended culture anaerobic condition, but it couldn't promote green algae hydrogen photoproduction. Comparing to the PSII photochemical activity of C. reinhardtii was obviously inhibit by sulfur-deprived in medium, which of P. subcordiformis only was slightly depressed, couldn't photoproduce hydrogen. CCCP can inhibit the PSII photochemical activity of P. subcordiformis, which close related to the concentration of CCCP, the rate of hydrogen photoproduction obviously improved. Besides, CCCP can promote C. reinhardtii cc124 hydrogen photoproduction too, but which clearly inferior to that of C. reinhardtii cc124 by sulfur-deprived. There are dual effects on the PSII photochemical activity of C. reinhardtii cc124 by addition CCCP and sulfur-deprived in medium, but has low capacity of hydrogen production.The effects of metabolism and electron source on hydrogen photoproduction of P. subcordiformis treated with CCCP after anaerobic dark incubation wereinvestigated,which indicated that the metabolism of P. subcordiformis was fermentation during anaerobic dark incubation and hydrogen photoproduction after addition CCCP, and about 90% electron need for hydrogen photoproduction come from water oxidation by PSII, the remaining 10% probably transfer from endogenous substrate degradation.Further study the effect of medium on endogenous substrate accumulation and hydrogen photoproduction by P. subcordiformis. The improved medium can obviously accelerate the growth of P. subcordiformis and accumulate much more endogenous substrate, which can't improve its hydrogen photoproduction treated with CCCP,but P. subcordiformis growth in improved medium can photoproduce trivial hydrogen by sulfur-deprived during direct light illumination...