Syntrophic acetate oxidation in industrial CSTR biogas digesters.

Highlights: [•] 10 out of 13 randomly selected biogas plants showed syntrophic acetate oxidation (SAO). [•] High SAO bacteria (SAOB) abundance despite differences in operation parameters. [•] Stable levels of SAOB under variable operating conditions. [•] SAOB correlated positively with low abundance of aceticlastic methanogens. [•] The thermophilic SAOB T. phaeum correlated with high ammonia levels. [Copyright &y& Elsevier]