Heterotrophic methanogens dominate in anaerobic digesters

In the present study, we conducted phylogenetic, metagenomic and metatranscriptomic analyses of microbiomes established in thermophilic packed-bed anaerobic digesters fed acetate as the major substrate, with the particular focus on characterizing the genomic and metabolic features of uncultured methanogens that preferentially grew there. Deep sequencing of metagenomes and precise binning of assembled contigs reconstructed complete and high-quality draft genomes for abundant methanogens and associated bacteria. Furthermore, metatranscriptomics were conducted to reveal transcriptional dynamics of methanogens in response to shifts in organics-loading rates.