Kornél KOVÁCS
Head, Principal Investigator

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Gábor RÁKHELY Staff Scientist, Principal Investigator
Judit MARÓTI Staff Scientist
András TÓTH Staff Scientist
Andrea NYILASI Staff Scientist
Ágnes KIS PhD Student

REDOX METALLOENZYMES AND THEIR APPLICATIONS

Biogas

Photosynthesis and photosynthetic organisms are widespread on Earth, hence an oxidizing atmosphere had developed long time ago. As a consequence, most compounds found in the environment as waste or contamination are in oxidized state. Their conversion and utilization in many cases is only possible through reduction. There is no better reductant for biotechnological elimination of these compounds than the hydrogen produced by certain bacteria on site. This principle is used for the intensification of biogas production, a biotechnological process, which decomposes organic materials yielding biogas. Biogas is formed by a consortium of microbes in an oxygen-free environment. The microbial community consumes the complex molecules of organic waste or biomass, because they exploit the chemical energy stored in the carbon-carbon bonds of these substrates. Since none of the individual microbes can break all carbon-carbon bonds, a well-organized, efficient microbiological food-chain develops in order to liberate all of the chemical energy that is used to fuel their own metabolism and growth. The organic molecules are split to smaller pieces, until there is no more carbon-carbon bond left and the leftover is released as biogas, i.e. a mixture of methane and carbon dioxide. The biological activity of the biogas-producing natural consortia is not optimized for maximum production of the gas, which is useless for the bacteria. We have demonstrated that the complex biochemical and microbiological reaction chain can run faster and more efficiently if one properly interferes with some of the individual steps. The strategy was assessed both in laboratory experiments and field tests using animal slurry and manure, waste water sludge, various energy plants, industrial waste and solid household waste. The biotechnological management of the microbial activity leads to more economical and cost-effective biogas production technology.

Selected publications

Bagi, Z., Ács, N., Bálint, B., Horváth, L., Dobó, K., Perei, K.R., Rákhely, G. and Kovács, K.L. (2007). Biotechnological intensification of biogas production. Appl. Microbiol. Biotechnol. 76: 473-482.