Antibacterial, Antibiofilm, and Antioxidant Activity of Polysaccharides Obtained from Fresh Sarcotesta of : Bioactive Polysaccharide that Can Be Exploited as a Novel Biocontrol Agent.

() biofilm plays an important role in the persistence of chronic infection due to its resistance to antibiotics. Because of their functional diversity, active polysaccharide is increasingly being applied as a biocontrol agent to inhibit the formation of biofilm by pathogens. In this study, a new polysaccharide, GBSPII-1, isolated from the fresh sarcotesta of . () was characterized and its effect on antibiofilm formation of was examined . High-Performance Liquid Chromatography (HPLC) analysis showed that GBSPII-1 is an acidic heteropolysaccharide composed of mannose, rhamnose, glucose, glucuronic acid, and galacturonic acid. GBSPII-1 demonstrated a molecular weight of 34 kDa and may affect the accumulation of polysaccharide intercellular adhesion (PIA) by inhibiting A, B, C, and D gene expression at subinhibitory concentrations. Under 10 g/L, GBSPII-1 showed an antioxidant effect on the inhibition rate of HO-induced erythrocyte hemolysis and the scavenging rate of DPPH radicals was 76.5 ± 0.5% and 89.2 ± 0.26%, respectively. The findings obtained in this study indicate that GBSPII-1 has antibacterial effect, is a possible source of natural antioxidants, and may be a potential biocontrol agent for the design of new therapeutic strategies for biofilm-related infections.