Implementing Metabolomics Tools to Optimise the Production of Anti-Biofilm Metabolites of Endophytic Fungi from Scottish Seaweedsv

An increasing number of compounds with new structures and various bioactivities are recently being isolated from marine fungal sources. A metabolomics approach was used to aid media selection for the growth algal endophytic fungi and optimum production of their anti-biofilm metabolites. Anti-biofim activity has played an important role in multi-resistance of pathogenic bacteria like those of Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa.
The endophytic fungus Dendryphilla salina obtained from marine Scottish seaweed Laminaria hyperborea, was grown on nine different media namely: malt extract, rice, oat, and Wickerham media either incorporated with or without sea salt and in marine broth as well. Incubation periods were accomplished at three different growth phases. Fungal extracts were then prepared from the different fermentation conditions and their chemical profiles were analysed through nuclear magnetic resonance (NMR) spectroscopy and HPLC-coupled high-resolution mass spectrometry (HPLC-HRMS). The spectral data were processed and dereplicated using the Dictionary of Natural Products (DNP) database. The processed data were also subjected to multivariate analysis to target the bioactive metabolites and establish the optimum conditions for their production. The extracts were tested for anti-biofilm activity by Alamar Blue and planktonic solution bioassays. Three fungal extracts obtained from malt media both with and without sea salt as well as the oat media with sea salt were found active affording 100% inhibition of biofilm formation at concentration of 100μg/mL. From the multivariate data analysis, three new metabolites were targeted for isolation work.