The authors observed how flocculated biomass presented higher solubilization and methane pro-duction (about 55 g CH4/kgTS) in comparison with the control sample (about 45 g CH4/kgTS) during the first 6 days; while after 10 days of digestion the methane production seemed to be in hibited.Thiswasattrib-uted to the greater size of flocs, which may impede efficient bacteria movement within the sludge flocs,hindering the subsequent acidogenic and the methanogenic stages to produce methane.