INSOLUBLE BIODEGRADATIVE POTENTIAL OF THE VENICE LAGOON

The sediment phase of the Venice lagoon within an area of shallow wate r, the Palude della Rosa, was studied and three insoluble enzymatic ac tivities (cellulase, phosphatase and urease) were found to be linked t o the inorganic phase. These immobilized enzymes were more resistant t o environmental changes, even extreme ones, compared to their soluble counterparts. The evolution of their activity with pH, temperature and seasonal variation was investigated. While pH related activities show ed the usual behaviour, the resistance to temperature was extremely hi gh and seasonal variation was dependent on immobilization. These enzym atic activities could be used as a diagnostic factor for the ecosystem , since their presence is related to the nature of the waste products.