Antimicrobial and Fermentation Potential of in Food Applications.

is a brown oceanic seaweed rich in bioactive compounds. It could play an important role in food production because of its antimicrobial and antioxidant properties. Three strains belonging to the group (, , and ) and a strain were used for the solid-state fermentation of commercial seaweeds, and bacterial growth was monitored using the plate count method. High-pressure processing (HPP) was also employed (6000 bar, 5 min, 5 °C) before extraction. The antimicrobial activity of the extracts was tested in terms of the main food pathogenic bacteria ( spp., , , , and ), and the phenolic content was estimated using the Folin-Ciocalteau method. In addition, targeted UHPLC-MS methods were used to unravel the profile of phlorotannins. allowed the growth of the group strains and , showing the fermentability of this substrate. Significant antimicrobial activity toward was observed in the extracts obtained from unfermented samples, but neither fermentation nor HPP enhanced the natural antimicrobial activity of this seaweed species. The content in the phenolic compounds decreased because of the fermentation process, and the amount of phenolics in both the unfermented and fermented extracts was very low. Despite phlorotannins being related to the natural antimicrobial activity of this brown seaweed, these results did not support this association. Even if fermentation and HPP were not proven to be effective tools for enhancing the useful compounds of , the seaweed was shown to be a suitable substrate for group strains as well as for growth, and its extracts exhibited antimicrobial activity toward foodborne pathogens.