The ANTI-BIOFILM AND ANTI-FOULING ACTIVITY OF POLYSACCHARIDE FROM AGARDHIELLA SUBULATA (RHODOPHYTA)

Abstract

In an ongoing screening for novel environment-friendly anti-biofouling molecules, in this study, crude polysaccharide (κ-carrageenan, A1), extracted from Agardhiella subulata (Rhodophyta), collected from Lake of Ganzirri (Italy), was evaluated for its effects on biofilm formation of the pathogens relevant in aquacultures and human health. A1 showed dose-dependent (100-400 μg/mL) inhibitory activity on the biofilm formation without exerting antibacterial activity. At the highest concentration 400 μg/mL A1 showed antibiofilm activity against both Gram-positive and Gram-negative bacteria. As assessed by the surface coating assay and the microbial adhesion onto hydrocarbons, A1 was able to inhibit the bacterial adhesion to polystyrene surfaces and modify their cell-surface properties (charges/hydrophobicity). The results suggested that the algal extract hindered the first phases of the biofilm formation. Moreover, A1 was not toxic indicating its safety and potential use for marine environmental applications.