Waste activated sludge (WAS) generates from wastewater treatment plants (WWTPs) contain recalcitrant cell walls, extracellular polymeric substances (EPS), inorganic materials that are difficult to degrade due to the stability of floc structure and microbial cell walls. In addition the WAS also contain extracellular enzymes entrapped in sludge matrix. Extracellular enzymes demand much more care and attention since they are inevitable for sludge hydrolysis. On considering the exocellular enzyme location in the floc matrix, EPS is the significant factor masking the sludge enzyme activity on flocs. EPS makes the flocs stable and provide a barrier like protection for sludge biomass from harmful effects. Removal of EPS could enhance the sludge extracellular enzyme activity.