Fig. 4.

Taxonomic (genus) composition of archaea in the anaerobic digester plants. Taxonomic composition based on 16S archaea-specific amplicon sequences is shown. a The three-stage plant (CD) in Jena, (b) leach-bed reactors, and (c) sewage plants. The grey scale (top right) corresponds to biogas production values as in Fig. 2. Samples corresponding to the storage tank of the digestion remnants reactor (CD-Jena S3) are not shown as they failed to produce any amplicon with the selected oligonucleotides. Methanogenesis pathways are shown in (d) three stage plant, (e) leach-bed reactors, and (f) sewage plants