Substrate specificity and ion inhibition of bacterial and particle associated alkaline phosphatases of waters and sewage sludges

Summary

The alkaline phosphatase activity of particulate matter derived from a variety of environments differing in ambient orthophosphate concentration has been examined. Orthophosphate inhibition of enzyme activity was directly related to the ambient orthophosphate concentration of the source of the particulate matter. Extracts of particulate matter from selected sites hydrolysed a range of inorganic and organic phosphates. Inhibition of phosphatase activity by cations was generally less powerful than that by anions. Of the metals likely to occur in waste waters, cadmium, nickel, zinc, and copper showed some degree of inhibition; tungstate was a strong inhibitor of all extracts. The behaviour of extracts bore a closer resemblance to that of a constitutive enzyme than to that of an inducible enzyme, but the similarity was shallow. The hydrolytic behaviour of particulate matters is likely to be influenced by many factors including the nutritional and physico-chemical status of the environment.