About us
Biogas Infos
Biogas in general
Monitoring/Process control
Main Research

You are here: Biogas Infos  › Biogas in general  › Microbiology  › 

Microbiology in biogas reactors

Due to different microorganisms in the Biogas-Reactor organic compounds will be degraded and metabolized. The microorganisms community depends on a lot of different factors – like pH in the media, temperature, feeding material,…
But a few things they have in common:

  • they are strictly anaerobic (would be inhibited or even killed by oxygen)
  • they have their optimum proliferation rate near pH 7
  • reducing agent must be present
  • temperature should be at least 30°C
  • degradation of organic compound takes place in four successive steps (hydrolysis, acidogenesis, acetogenesis, methanogenesis)
During hydrolysis the polymers are divided into monomer basic modules or any other useful degradation product by different hydrolytic (more specific cellulolytic, amylolytic, proteolytic and lipolytic) bacteria.
E.g. Starch will be degraded to glucose by Bacteroides or Clostridia

During acidogenesis we monitor degradation to fatty acids, organic acids, and alcohol and with following acetogenesis further dismantling of these products to acetic acid, CO2 and H2.

The last step, the methanogenesis, degrades acetic acid to methane and carbon dioxide.

…and even the decomposition products of the other reaction are transformed to biogas.

This last step is catalyzed by Methanobacteria, which can only convert C1 and C2 molecules.

© Biogas Research & Consulting Group at IFA-Tulln
Konrad Lorenz Strasse 20 • 3430 Tulln • AUSTRIA
Phone: +43 (0)1 47654-97424 (NEW!) • Fax: +43 (0)1 47654-97409 (NEW!)