The auto fluorescence characteristics, specific activity, and microbial community structure in batch tests of mono-chicken manure digestion

[Display omitted] •Optimal TS of 10–12% chicken manure mono-digestion was obtained in batch test.•FA, TS and pH significantly influence the EEM-PARAFAC components in time series.•SMP-like C2 and protein-like C4 were significantly related to bio-methane production.•In-situ metabolic tests showed the cooperation of variable balanced functional groups.•Methanosaeta and Syntrophobacter predominated the metabolic of CH4 generation. Batch tests inoculated with granular and suspended sludge of mono chicken manure (CM) digestion were conducted. Kinetic analysis showed a maximum bio-CH4 generation (6 mL/gVS/d) at an optimal TS of 10–12%. At a TS of 25%, serious inhibition was found for granular sludge and even greater inhibition for the suspended sludge caused by free ammonia. The auto fluorescence of Excitation–mission matrix with parallel factor analysis (PARAFAC) showed that the dissolved organic matter (DOM) varied between the form C1, C2, C3 and C4. The split component of the SMP-like C2 and protein-like C4 significantly related to the bio-methane production in time series. The canonical correlation analysis (CCA) indicated that ammonia, pH, and TS influenced the PARAFAC component significantly. The aceticlastic methanogens of the genus Methanosaeta and acetogens of the genus Syntrophobacter predominated in the CM sludge. The methanogens and acetogens formed a metabolic cooperation, making the process a stable methane produced activity.