Characterization of Bacterial Biomass Potential Activity by Proteolytic Activity Measurements

Bacterial protease activity was assayed using the L Leucine ß naphthylamide as artificial substrate. Apparent KM values ranging from 112 to 606 ymoles of substrate consumed /g of biomass (dry weight) were obtained with activated sludge samples. Specific activities were in the range from 7 to 26 umoles of substrate consumed/min/g of sludge (dry weight). It was established that proteolytic activity from various bacterial populations (Klebsiella aerogenes, Bacillus cereus and activated sludge) can be conveniently measured at 30°C and pH 8.5. In these conditions, the substrate and product molecules of the protease assay are non biodegradable, non toxic and not significantly adsorbed by the biomass.