Phototrophic hydrogen production by agar-immobilized Rhodobacter capsulatus

Elkahlout, Kamal E. M.
photosynthetic bacteria is attractive field as production is fueled by solar energy. Hydrogen production potential of two photosynthetic bacteria R.capsulatus (DSM1710 wild type and R.capsulatus YO3 Hup- uptake hydrogenase deleted mutant strain) were examined in agar immobilized systems. In the present work agar and glutamate concentrations were optimized for immobilization of bacteria while feeding bacteria with 40/2-4 mM acetate/ glutamate. Immobilized bacteria produced hydrogen for 420-1428 hours covering 5-7 rounds. Optimizing of acetate concentration indicated that 60 mM produced the highest observed yield around 90-95%. Results shown that 2.5 mg dry cell weight/mL is the optimum cell concentration for wild type strain while 5 mg dry cell weight/mL was optimum for YO3 strain. Using either glycerol or sodium dithionite caused decrease in hydrogen production capacity of immobilized bacteria. It was observed that agar provided protection against inhibition effect of ammonium. Co- v immobilization of bacteria with packed cells of H. salinarium increased total hydrogen production capacity by about 1.14-1.41 folds. Hydrogen production by immobilized bacteria in panel photobioreactor was achieved by a novel system which allowed long term hydrogen production. Immobilized R. capsulatus DSM 1710 in panel reactor worked for about 67-82 days covering 4-5 rounds while immobilized R. capsulatus YO3 worked for 69-72 days covering seven rounds.


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Utilisation of solar energy by photosynthetic microorganisms for H-2 production attracts much interest due to unlimited supply of energy. It is important to identify the most effective strain in terms of hydrogen production for the feasibility of the process. Four different strains of Rhodobacter sp. were grown in a water-jacketed cylindrical glass-column photobioreactor under anaerobic conditions. Growth characteristics and hydrogen production rates were determined. Comparison between strains of Rhodobacte...
Photofermentative hydrogen production using dark fermentation effluent of sugar beet thick juice by Rhodobacter Capsulatus
Özkan, Endam; Gündüz, Ufuk; Uyar, Başar; Department of Biotechnology (2011)
Biological hydrogen production through integration of dark and photo-fermentation by using biomass is a promising alternative for energy supply problems. The main purpose of this study was to investigate photobiological H2 production by the purple non-sulfur (PNS) bacteria Rb. capsulatus on dark fermentation effluent of sugar beet thick juice (DFESBTJ). Presence of NH4+ in effluents is an important parameter since NH4+ inhibit the nitrogenase enzyme activity. Therefore, the influence of different NH4+ conce...
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Yavuzyılmaz, Ezgi; Üner, Deniz; Kıncal, Serkan; Department of Chemical Engineering (2016)
Hydrogen production by solar thermal water splitting is an eco-friendly way of storing solar energy in chemical bonds. The most important obstacles for the viability and the commercialization of this technology are lower energy efficiencies and higher production costs compared to conventional hydrogen production ways such as steam reforming, coal gasification, and electrolysis of water. Two-step thermochemical hydrogen production by using solar energy is an alternative method to conventional hydrogen produc...
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Pişkin, Fatih; Öztürk, Tayfur; Department of Metallurgical and Materials Engineering (2013)
Industrial production of hydrogen from the syngas, generated from steam reformation of natural gas or coal gasification, sets conditions for hydrogen separation membranes in terms of operating conditions. An alternative source for hydrogen is a syngas generated by gasification of municipal solid wastes which are likely to set more stringent conditions for the separation membranes. There is therefore, a growing demand for separation membranes with improved permeability and particularly of low cost. Among var...
Hydrogen storage in magnesium based thin films
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Citation Formats
K. E. M. Elkahlout, “Phototrophic hydrogen production by agar-immobilized Rhodobacter capsulatus,” Ph.D. - Doctoral Program, Middle East Technical University, 2011.