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PRODUKCJA WODORU W PROCESACH
PROWADZONYCH PRZEZ DROBNOUSTROJE
Anna Sikora
Instytut Biochemii i Biofizyki PAN, ul. Pawińskiego 5a, 02-106 Warszawa
tel. (022) 592-33-37, 
Wpłynęło w maju 2008 r.
1. Wprowadzenie. 2. Produkcja wodoru w procesach biologicznych. 2.1. Bezpośrednia biofotoliza. 2.2. Pośrednia biofotoliza. 2.3. Fermentacje bakteryjne. 2.3.1. Powstawanie pirogronianu. 2.3.2. Fermentacja masłowo-butanolowa. 2.3.3. Fermentacja kwasów mieszanych. 2.3.4. Regulacja produkcji wodoru w czasie fermentacji kwasów mieszanych. 2.3.5. Substraty fermentacji. 2.3.6. Wydajność produkcji wodoru w procesie fermentacji. 2.3.7. Sposoby zwiększania wydajności
produkcji wodoru w procesach fermentacji. 2.4. Foto fermentacja. 2.5. Procesy fermentacyjne zachodzące w żwaczu. 2.6. Hydrogenosomy. 2.7. Hydrogenazy. 2.8. Bakterie redukujące siarczany. 3. Podsumowanie
Hydrogen production by microorganisms
Abstract: Hydrogen is considered as an attractive energy carrier that can replace conventional fossil fuels in the future. Current methods of hydrogen production are based on conventional fossil fuels like natural gas, petroleum and coal. These methods are energy-expensive and cause environmental pollution. This is the reason behind the great interest in hydrogen production from biomass by microorganisms under anaerobic conditions. This direction seems to be
very attractive because biomass is a versatile and renewable energy source and can be a method of utilization of various organic wastes. The article presents known biological processes leading to hydrogen production: dark fermentation, photofermentation, direct and indirect biophotolysis, anaerobic respiration of sulphate-reducing bacteria under conditions of sulphate depletion. Dark fermentation and dark fermentation followed by photofermentation seem to be
the most promising concepts for the future applications. Many investigations now are focused on improving the yield of hydrogen during fermentation. Molecular techniques like the analysis of 16S rRNA gene or fluorescent in situ hybridization (FISH) are employed to identify and isolate new species of hydrogen-producing bacteria. Hydrogenases are key enzymes responsible for hydrogen evolution in all of the known biological processes. They are metalloenzymes
carring out a simple chemical reaction: 2H+ + 2e- <-> H2. In anaerobic hydrogen-producing eukaryotic microorganisms hydrogenases are usually located in special organella hydrogenosomes. Hydrogenosomes are an adaptation to anaerobic conditions and become energetic centers of the cell. Microorganisms responsible for hydrogen production in rumen, a specific fermentative chamber, are also described.
1. Introduction. 2. Hydrogen production in biological processes. 2.1. Direct biophotolysis. 2.2. Indirect biophotolysis. 2.3. Dark fermentation. 2.3.1. Pirogronian formation. 2.3.2. Butyrate-butanol fermentation. 2.3.3. Mixed-acid fermentation. 2.3.4. Regulation of hydrogen production during mixed-acid fermentation. 2.3.5. Substrates for hydrogen fermentation. 2.3.6. Hydrogen yield during fermentation. 2.3.7. Improvement of hydrogen yield during fermentation.
2.4. Photofermentation. 2.5. Rumen fermentation. 2.6. Hydrogenosomes. 2.7. Hydrogenases. 2.8. Sulphate reducing bacteria. 3. Summary
Słowa kluczowe: wodór, fermentacja, biomasa, hydrogenazy, fotoprodukcja
Key words: hydrogen, fermentation, biomass, hydrogenases, fotoproduction
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