141 | An inverted taxonomic approach unveils diversity of cladophoraceae (Chlorophyta) in two nature oriented reserves in northern Sicily (Italy)

Matteo Vita¹, Vincenzo Zammuto¹, Mattia Soppelsa¹, Fabio Mondello¹, Salvatore Giacobbe², Marina Morabito¹, Antonio Manghisi¹ | ¹Dept. of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Italy; ²CNR-IRBIM, Messina, Italy.

Cladophoraceae (Chlorophyta) is a family of algae inhabiting a wide range of aquatic environments, ranging from marine, brackish and freshwater, which can express a massive growth in eutrophic conditions, with a significant impact on the environment. Within the framework of systematic floristic surveys carried out in two Oriented Nature Reserves in northeastern Sicily, namely Laguna di Capo Peloro and Laghetti di Marinello, both protected areas within the Natura 2000 network, and differently affected by anthropic pressure, the presence and distribution of Cladophoraceae species were examined. An inverted taxonomic approach was applied, and the biotechnological potential of those forming large biomass was evaluated. Three sampling campaigns per year have been performed since 2023. Thalli of any apparently diverse morphology of filamentous green algae were sampled from each pond, brought to the laboratory under low temperature, and washed with clean water for removing associated fauna and flora. From each sample a voucher was pressed as herbarium sheet and a subsample dried in silica gel for DNA barcoding identification (1, 2). Partial nuclear large subunit rRNA gene was PCR amplified and sequenced and clusters of genetic species were inferred with a neighbor-joining approach as performed in PAUP*. In a subsequent step, each genetic species was analysed with a morpho-anatomical approach to verify diagnostic characters. At present, a total of 8 species were identified, of which 4 belonging to the genus Cladophora, 3 to the genus Chaetomorpha, and a single one to the genus Rhizoclonium. Among those, Chaetomorpha sp.3 (tentatively identified as C. aerea) is the species producing the largest biomass in Capo Peloro lagoon, from where it is periodically removed and treated as a waste. Previous study indicated this species as a potential source of phycocolloids with interesting physicochemical properties, such as high emulsifying activity, and biological properties such as antibiofilm activity against pathogens relevant in aquaculture, excluding any toxic effect against two model organisms in aquaculture, Artemia salina and Danio rerio (3, 4). Furthermore, as based on interviews with local farmers and elderly residents of the area, a traditional use (early-mid 20th century) of macroalgae from the lagoon as fertilizers and mulches in vineyards and gardens emerged. In the present research, C. aerea from Capo Peloro lagoon has been selected for further investigations on its potential use as fertilizer and mulches in agricultural soils. This approach of reverse taxonomy showed good results in the identification of Cladophoraceae species, and it could be a reliable method for the traceability of species of applicative interest.