Tamaricicola fenicei sp. nov. (Pleosporaceae, Pleosporales), a New Marine Fungus with Significant Antiviral Activity

In this study, seven Pleosporaceae strains isolated from the seagrass <i>Posidonia oceanica</i> and the jellyfish <i>Pelagia noctiluca</i> 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, <i>Tamaricicola fenicei</i> sp. nov. was proposed. Multi-locus phylogenetic analyses, using the nuclear ribosomal regions of DNA (nrITS1-nr5.8S-nrITS2, nrLSU, and nrSSU) as well as the <i>rpb2</i> and <i>tef-1α</i> gene sequences, strongly supported the new taxon. The phylogenetic inference, estimated using Maximum Likelihood and Bayesian Inference, clearly indicates that <i>Tamaricicola fenicei</i> sp. nov. forms a distinct clade within the monospecific genus <i>Tamaricicola</i>. 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 <i>Staphylococcus aureus</i> ATCC 25923.