The microbial community uses extracellular enzymatic activities (EEA) to initialize degradation of high molecular weight organic matter in all the ocean. The intrusion of the warm Circumpolar Deep Water (CDW) into the Antarctic shelf area is one of the recognized drivers of ice shelf melting, playing an important role on the shelf physical and biological processes. The investigated areas covered: a) the Drygalski Ice Tongue and the nearby Terra Nova Bay polynya; b) the coastal area between the Mariner and Aviator glaciers; c) the Antarctic continental Shelf Break area near Cape Adare (North Victoria Land). During an oceanographic cruise performed in the framework of the CELEBeR (CDW effects on glacial melting and on bulk of Fe in the Western Ross Sea) project (funded by Italian PNRA), the EEA distribution was studied in order to investigate the spatial and depth patterns in the Ross Sea. In particular rates of leucine-aminopeptidase -LAP, ?-glucosidase -GLU and alkaline phosphatase -AP were measured. The contribution of free enzymes fraction in some stations was also determined and the relationships with the main environmental parameters were analyzed. Results suggested the potential capability of the microbial community to decompose proteins, carbohydrates and organic phosphates. In the Shelf Break area LAP values showed higher values than Terra Nova Bay at surface. The decreasing trend with increasing depth was confirmed. Hydrology had also effect on EEA distribution.
Extracellular enzymatic activities in the Ross Sea (CELEBeR project).
Zaccone R;Azzaro F;La Ferla R;Azzaro M
2018
Abstract
The microbial community uses extracellular enzymatic activities (EEA) to initialize degradation of high molecular weight organic matter in all the ocean. The intrusion of the warm Circumpolar Deep Water (CDW) into the Antarctic shelf area is one of the recognized drivers of ice shelf melting, playing an important role on the shelf physical and biological processes. The investigated areas covered: a) the Drygalski Ice Tongue and the nearby Terra Nova Bay polynya; b) the coastal area between the Mariner and Aviator glaciers; c) the Antarctic continental Shelf Break area near Cape Adare (North Victoria Land). During an oceanographic cruise performed in the framework of the CELEBeR (CDW effects on glacial melting and on bulk of Fe in the Western Ross Sea) project (funded by Italian PNRA), the EEA distribution was studied in order to investigate the spatial and depth patterns in the Ross Sea. In particular rates of leucine-aminopeptidase -LAP, ?-glucosidase -GLU and alkaline phosphatase -AP were measured. The contribution of free enzymes fraction in some stations was also determined and the relationships with the main environmental parameters were analyzed. Results suggested the potential capability of the microbial community to decompose proteins, carbohydrates and organic phosphates. In the Shelf Break area LAP values showed higher values than Terra Nova Bay at surface. The decreasing trend with increasing depth was confirmed. Hydrology had also effect on EEA distribution.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
