Degradazione microbica della sostanza organica nei sedimenti superficiali del Mar Piccolo di Taranto

During two cruises carried out in the Mar Piccolo (Taranto) the microbial components, both heterotrophic and anaerobic, and the microbial enzymatic activities of four enzymes ?leucine aminopeptidase (LAP), alkaline phosphatase (AP), ?-glucosidase (?-Glu) e ?-glucosidase (?-Glu)? of surficial sediments were evaluated. The environmental parameters, as temperature, pH and Eh, together with granulometric measurements and geochemical parameters, like organic and inorganic carbon, total nitrogen, organic and inorganic phosphorous of sediments were also examined in the basin. Organic carbon concentrations resulted higher than those of other lagoon areas. During October 2000, it was observed an increase of bacterial heterotrophic abundance, associated to an increase of LAP activity, due mainly to higher temperatures. In 1999, the bacterial heterotrophic abundance resulted well related to LAP and ?-Glu activities. Anaerobic bacteria (Clostridium spp., sulfide-reducing) showed a significant correlation with mud fraction in 1999. Moreover, they resulted well correlated to enzymatic activities of LAP, AP and ?-Glu in 1999, indicating that anaerobic component may contribute to enzymatic activities.