ASSAY FOR DETERMINATION OF ALPHA-AMYLASE ACTIVITY IN ACTIVATED-SLUDGEMIXED BACTERIAL COMMUNITIES

In municipal wastewater a significant fraction of the biodegradable ma terial is comprised of macromolecular carbohydrates. This complex mate rial must be hydrolyzed enzymatically prior to bacterial uptake and ut ilization. An assay method was developed to monitor the overall rate o f alpha-amylase hydrolytic activity in a mixed culture of activated sl udge. The method is based on the tracer material amylose azure, a pota to starch covalently labelled with Remazol Brilliant Blue R dye. Resul ts of batch experiments under aerobic, anoxic and anaerobic conditions indicate marked differences in the rate of cleavage of alpha(1-4) glu can bonds. The hydrolysis rate of the complex carbohydrate material in activated sludge was found to be highest under anaerobic conditions a nd lowest under aerobic conditions, with an intermediate value under a noxic conditions.