Substrate colonization in the Ross Sea, Antarctica: the ANT-BIOFILM Project

Microbial biofilms play a key role in substrate colonization in aquatic environments, as hot spots of biodiversity and sources of secondary metabolites with biotechnological potential. In Terra Nova Bay (Ross Sea, Antarctica), microbial biofilm communities are under-explored in their structure and functions; particularly, their response to environmental and/or anthropogenic forcings remains to be elucidated yet. Funded by National Antarctic Research Program (XXXIII Italian expedition), the ANT-Biofilm project "Microbial colonization of benthic ANTarctic environments: response of microbial abundances, diversity, activities and larval settlement to natural or anthropogenic disturbances and search for secondary metabolites" (PNRA16_00105) includes short and long term (3-12 months) experiments in two bays (Road Bay and Tethys Bay) characterized by anthropogenic (i.e. sewage) and natural (i.e. low salinity) stressors, respectively. Total, viable and respiring prokaryotes, culturable bacteria, potential enzymatic activity rates, physiological community profiles, microalgae and macrobenthic community are studied. Selected biofilm samples will be sequenced and analyzed by hybridization (i.e. Card-FISH) and bacterial isolates screened for antibiotic resistance and metabolite production. Physical-chemical environmental characterization will be performed. This contribution reports the preliminary results obtained by the four Research Units during the short term experiments.