Insoluble biodegradative potential of the venice lagoon

Abstract

The sediment phase of the Venice lagoon within an area of shallow water, the Palude della Rosa, was studied and three insoluble enzymatic activities (cellulase, phosphatase and urease) were found to be linked to the inorganic phase. These immobilized enzymes were more resistant to 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 showed the usual behaviour, the resistance to temperature was extremely high and seasonal variation was dependent on immobilization. These enzymatic activities could be used as a diagnostic factor for the ecosystem, since their presence is related to the nature of the waste products.

Biodiversity of prokaryotic communities in sediments of different sub-basins of the Venice lagoon

“…These bacteria had been previously isolated from the marine algae Ulva fenestrata, able to degrade proteins and complex polysaccharides [17]. U. fenestrata colonizes sediments of Palude della Rosa (station 2B), where intense cellulase activity has been measured, up to 800 mg O 2 kg À1 h À1 (d.w.), four times higher than in the other lagoon areas [21].…”

Variations in kinetics of alkaline phosphatase in sediments of eutrophic, shallow, Chinese lakes

“…In soils, kinetics of the immobilized enzyme conformed to Michaelis-Menten, and V max was lower and K m higher than those of the free enzyme (Rao & Gianfreda, 2000). Immobilized enzymes were more resistant to environmental changes compared to their soluble counterparts (Sabil et al, 1993). In Venice lagoon sediments within a shallow water area, phosphatase activity was prolonged by its insolubility (Sabil et al, 1994).…”