The Role of Fucoidan in Controlling Listeria monocytogenes Biofilms on Seafood-Contact Surfaces

Seafood-borne pathogens, especially Listeria monocytogenes, pose a significant risk to global health, with the formation of biofilm on abiotic surfaces exacerbating contamination risks in the seafood industry. This investigation evaluates the biofilm inhibition efficacy of fucoidan against L. monocytogenes biofilms on commonly used processing surfaces. The minimum inhibitory concentration (MIC) of fucoidan was determined to be 150 µg/mL, and sub-MIC concentrations (1/8, 1/4, and 1/2 MIC) were assessed for their effects on inhibition of biofilm. This action resulted in a substantial, dose-dependent reduction in formation of biofilm, with maximum reductions of 2.91 log CFU/cm2 on hand gloves (HG), 2.46 log CFU/cm2 on silicone rubber (SR), and 2.11 log CFU/cm2 on stainless steel (SS). Gene expression analysis via real-time quantitative polymerase chain reaction (RT-qPCR) revealed the downregulation of quorum-sensing (QS) and virulence-associated genes (flaA, fbp, prfA, hlyA, and agrA), indicating fucoidan’s potential to inhibition of biofilm and bacterial pathogenicity. These results emphasize fucoidan as a promising environmental antimicrobial agent for mitigating L. monocytogenes biofilm in seafood handling environments, thus improving food safety and reducing contamination risks.