Microbial communities in biogas reactors and their link to stability and performance

The Anaerobic digestion (AD) of organic material gathers a great interest worldwide due to the global needs for waste recycling and renewable energy production. Biogas, the end product of an AD process, is a mixture of methane and carbon dioxide. Biogas can be used for heating, electricity or upgraded to pure methane for vehicle fuels. It could also serve as a part of the cycle in biorefineries. Although widely applied for energy production, an improved knowledge regarding the underlying microbial community is desired to ensure stable and efficient energy production. Therefore, the studies described in this thesis aimed to increase the knowledge base of microbial community in biogas reactors and relate this to stability and performance of the digestion process