183752.fig.002
Figure 2: Methanogenesis in anaerobic digestion as documented for normal waste treatment reactor systems [42]. The SAB consist mostly of Clostridium sp. at both mesophilic and thermophilic conditions [43]. The hydrogenotrophic methanogens in both mesophilic and thermophilic anaerobic digesters belong to the two orders of Methanobacteriales and Methanomicrobiales [44].