Tamaricicola fenicis sp. nov. (Pleosporaceae, Pleosporales), a new marine fungus with significant antiviral activity

In this study, seven Pleosporaceae strains isolated from the seagrass Posidonia oceanica and the jellyfish Pelagia noctiluca in the central Tyrrhenian Sea were characterized using a polyphasic approach (morpho-physiological, molecular, and phylogenetic analyses). Based on multi-locus phylogenetic inference and morphological characters, a new species, Tamaricicola fenicis was proposed. Multi-locus phylogenetic analyses, using the nuclear ribosomal regions of DNA (nrITS1-nr5.8S-nrITS2, nrLSU, and nrSSU) as well as the rpb-2 and tef-1α gene sequences, strongly supported the new taxon. The phylogenetic inference, estimated using Maximum Likelihood and Bayesian Inference, clearly indicates that Tamaricicola fenicis sp. nov. forms a distinct clade within the monospecific genus Tamaricicola. The antimicrobial activity of the chloroformic and butanolic extracts from malt agar cultures of the new species exhibited interesting antiviral and antibiofilm properties. In particular, a MIC of 3.0 µg/mL was observed against the Echovirus E11 in Vero-76 cells; moreover, a biofilm BIC50 reduction at 53 µg/mL was observed against Staphylococcus aureus ATCC25923.