Ammonium-induced changes of methane yield and prokaryotic community structure in the anaerobic digestion of swine manure

In this study, the biomethane potential and prokaryotic community structure in the anaerobic digestion of swine manure under various ammonium concentrations were investigated using Miseq sequencing technique.Anaerobic digestion was performed in a 1000 mL reactor containing 800 mL fermentation slurry with final TS content of 6%, and operated at 35±2 ?. About 300 mL (TS 6%) swine manure was fed every 3 days. All the reactors were achieved to a similar steady conditions (at day 6), different concentrations of NH4Cl were added to all the reactors except for the control (ammonium concentration almost 1000 mg/L), so that the final ammonium concentrations achieved 2500, 4000, 5500 and 7000 mg/L throughout the whole operating period.