Selected Molecular Characterisation of Biogas Digesters

The better the knowledge of the microbial composition in a digester of a biogas plant, the better the control over the process. Especially in the case of a disturbed methane production it is important to know where exactly the fermentation process is inhibited. Otherwise precious time is wasted with measures “at the off chance” of hitting the root cause.

The selected analysis comprisees of the composition of methanogenic archaea to conclude the present pathway of methanogenesis, and the absolute quantification of methanogenic archaea, bacteria universal, and the so called “syntrophic” bacteria. This allows to detect possible bottlenecks in the methane production.

The relation between the amounts of methanogenic to the total of bacteria in a biogas digester allows to distinguish possible causes of an inhibition:

• too less syntrophic bacteria: unsufficientl lysis of long-chained substrate molecules
• too less methanogenic bacteria: disturbed methanogenesis
• both groups in too little amount
• wrong relation of methanogenic groups to each other: Change in the methanogenesis relation (hydrogenotrophic to acetoclastic)

Important: This analysis should be coordinated with the consultant of your biogas plant. It is not intended as a replacement of periodic physicochemical analysis!