ABSTRACT
Biomethane is the result of the anaerobic digestion of a wide range of substrates by the collaborative action of a diverse range of microorganisms whose number and identity at various stages of methanogenesis depends on the substrates used and the fermentation environment (Briones and Raskin, 2003; Demirel and Scherer, 2008). However, the digester has often been regarded as a black-box process converting substrate to biogas (Madden et al., 2010; Supaphol et al., 2011). This state of affairs is changing as it is realised that attention to the details of the fermentation process could lead to significant improvements in efficiency, control and industrial development of biogas production (Briones and Raskin, 2003; Rittmann et al, 2008).
