INTRODUCTION Uty
Photosystem I is a membrane pigment-protein complex in green plants, algae as well as cyanobacteria, and undergoes redox reactions by using the electrons transferred from photosystem II PS II 1 , These membrane proteins are considered to be especially interesting in the study of monomolecular assemblies, because their structure contains hydrophilic area that can interact with the subphase as well as hydrophobic domains that can interact either with each other or with detergent and lipids 2 ,...
INTRODUCTION Ayf
Hydrogen is a clean and highly efficient fuel that results in water upon burning without generating CO2. Among various hydrogen production technologies, biological conversion to hydrogen has received more attention as a sustainable technology since organic wastes, water and various gases are cheap starting materials. Photo-biological hydrogen production by purple non-sulfur bacteria is one of the most promising methods under photo-heterotropic conditions. The highest rate of photo-biological...
Lightdependant Processes
The low energy density of solar energy places severe economic restrictions on potential light-dependant biohydrogen processes. For example, at very favorable locations the yearly average solar irradiation could be as high as 5 kWh m2 day which would give 6.6GJ year. At a very optimistic conversion efficiency of 10 and a price for H2 of 15 per GJ only 10 worth of H2 m2 year would be obtained thus severely constraining construction and operational expenditures. Obviously, the situation worsens if...
Watersplitting Systems By Renewable Energy
Presently, more than 98 of the hydrogen gas consumed by the industries are provided by reforming coal, naphtha, and natural gas, and will be unable to bear the future demand 7 , It is strongly required to supply the hydrogen produced from water by renewable energy sources. Table 1 shows the water-splitting methods -lysis by the different kinds of energies. Hydrogen produced by water electrolysis is the traditional way since M. Faraday, however it cannot be qualified as clean energy carrier...
Hydrogen Utilization Systems
The precious ways of hydrogen utilization have the principles based upon the two non substitutive properties of hydrogen, that is, hydrogen energy systems are not only ecological but also energetic. Energetic means that hydrogen combustion has the high power chemical wattage that generates a big energy per unit time, which has been applied to the second stage of rocket launching. Ecological means that hydrogen can make not only the on site recycle by reversible physical reaction and or by...
Cyanobacterial Biohydrogen
Basically, two strategies are possible for cyanobacterial biohydrogen 1 H2 produced by nitrogenase, and 2 H2 produced by the bidirectional hydrogenase. Individual strains may harbor both a bidirectional hydrogenase though this is not a universal cyanobacterial enzyme , and none to several nitrogenase s , encoded by different structural genes. There is no report describing the existence of either several uptake hydrogenases or several bidirectional hydrogenases in a single cyanobacterial strain....
Possibilities Of Technological Methods In Solution Of Problems Raised In
Low efficiency of light energy byconversion Using continuous cultures in appropriate photobioreactor with sub-saturating light intensities we could get the efficiency of light energy bioconversion near to the potential one measured in short-term experiments under low light intensity . However, it is impossible to get the potential efficiency. For example, Rb. sphaeroides RV showed maximum efficiency of light energy bioconversion at 70 Wm2 Miyake, Kawamura, 1987 , Simultaneously, the rate of...
Results And Discussion
Monolayer behaviors of PS1 on various subphase surfaces It has been reported that cationic ions, such as Na and Cd2 , in the subphases are important for the formation of stable, active monolayers of PS II CC or bacterial reaction center from Khodobacter sphaeroides and Rhodopseudomonas viridis 2, 10 , We previously found that CaCh, poly-L-lysine and PBV in the subphase are also able to stabilize the monolayer formation of a hydrogenase from the phototropic bacterium T. roseopersicina 11,12 ,...
Photobiological Hydrogen Production Utrilizing Cyanobacteria
Merits of photobiological hydrogen production utilizing cyanobacteria Solar energy is the most abundant renewable alternative, and hydrogen is the most likely environmentally friendly future fuel. The amount of solar energy received on Earth's surface amounts to more than 6,000 times of the world social energy consumption Tab. 1 . However, solar energy is diffuse in intensity and its economical utilization is not easy Tab. 2 . In order that H2 substitutes for or supplements fossil fuels, its...
Hydrogen Enzyme Electrode For Renewable Energy
The hydrogen enzyme electrode is a device, which able to activate reversibly hydrogen molecule using catalytic activity of hydrogenase for energy interconversion between H2 and electricity. The effective electron exchange between the enzyme active site and electrode surface is required for function of this device, for example, in water electrolyzer, hydrogen fuel cells and other energy conversion systems. Several approaches were used to develop hydrogen enzyme electrodes based on direct and...
MATERIALS AND METHODS Gfn
Mal3 Phyt 2 was prepared as described previously 16 , EPC and a sulfoglycolipid sulfoquinovosyldiacylglycerol SQDG were purchased from Sigma Chemical Co. St. Louis, MO and Lipid Products South Nuffield, Surrey, UK , respectively. n-Octyl-p-D-glucoside OG was from Dojindo Kumamoto, Japan . Bio-Beads SM-2 was from Bio-Rad Laboratories Hercules, CA . All other chemicals were of a guaranteed reagent grade and purchased from Wako Pure Chemical Industries Osaka . Bacteriorhodopsin BR was prepared...
REFERENCES Xxq
1. PF. Weaver, JD. Wall, H. Gest 1975 Characterization of Rhodopseudomonas capsulata. Arch. Microbiol., 105 207-216 2. H. Biebl., N. Pfenning 1981 Isolation of member of the family Rhodosprillacaea, The Prokaryotes, Springer-Verlag, New York, pp.267-273 3. X. Y. Mao, J. Miyake, S. Kawamura 1986 Screening photosynthetic bacteria for hydrogen production from organic acids, J. Ferment. Technol, 64 245-249 4. JF. Burgess, R. Kawaguchi, A. Yamada, T. Matsunaga 1994 Rhodobacter marinus sp.nov. A...
Immobilized Cultures
Methods and matrixes for immobilization of photosynthetic microorganisms Immobilized cells are widely used for both practical and academic purposes. Immobilization techniques have been developed for cell stabilization and easy operation. The methods for immobilizing of the whole cells may be categorized as follows - entrapment by inert support like gel - adsorption by an inert support like ion exchange material - binding via immobilized biological macromolecules or attachment to the activated...
Materials And Methods
Rb. sphaeroides KD 131 wild type and its mutant strains 17 were obtained from Dr. J. Lee Sogang University, Korea . Rb. sphaeriodes KD131 was pre-cultured in the modified Sistrom's broth containing NH4 2S04 and L-aspartic acid as nitrogen sources and 35 mM succinic acid as a carbon source at 30 C for 20-24 hr under 7-8 klux m2 irradiance using halogen lamps 12V, 20W by illuminating at one side of serum bottles. The pre-cultures were centrifiiged to collect the cells and the cells collected were...
REFERENCES Kuc
1. Y. Kagawa, E. Racker 1971 J. Biol. Chem., 246 5477-5487 2. Y. Kagawa 1979 Methods Enzymol, 55 712-723 3. G. D. Eutan 1982 Biochim. Biophys. Acta, 694 185-202 4. P. W. M. Van Dijck, K. Van Dam 1982 Methods Enzymol., 88 17-25 5. R. P. Casey 1984 Biochim. Biophys. Acta, 768 319-347 6. R. D. Klausner, J. Van Renswonde, B. Rivnay 1984 Methods Enzymol, 104 340-347 7. A. Levitzki 1985 Biochim. Biophys. Acta, 822 127-153 8. E. Scheider, K. Altendorf 1987 Microbiol. Rev., 51 477-497 9. M. K. Jain, D....
Introduction To Biohydrogen
The spurred impetus has been given to developing non pollutant vehicles, and consequently, the clean cars driven by the fuel cells loading proton exchange membranes PEMFC , which based upon Nafion, have been surprisingly developed. A promising less pollutant and economical system is also expected, which will be the on site cogeneration system of electric power and the hot water supply with use of fuel cells combined with city gas pipe-lines. Such a spreading trend of non pollutant systems by...
RESULTS Yxj
Construction of His-tagged PS1 and PS2 from Thermosynechococcus elongatus In order to be able to isolate both PS1 and PS2 from the thermophilic cyanobacterium Thermosynechococcus elongatus by a one-step procedure and in order to immobilize both photosystems on the surface of the support materials i.e. the electrodes in an oriented manner, His-tags have been fused to the genes of appropriate subunits of these complexes. Care was taken to select sites which guarantee that - according to the model...