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Targeting systems for the treatment of infectious diseases
(Università della Calabria, 2025-02-21) Patitucci, Francesco; Angelone, Tommaso; Puoci, Francesco
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Studio di sistemi strutturati con fibre alimentari da sottoprodotti della lavorazione di agrumi
(Università della Calabria, 2025-02-27) Mammolenti, Domenico; Angelone, Tommaso; Gabriele, Domenico; Lupi, Francesca Romana
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Biodiversity and sustainable agriculture production in Calabria, southern Italy
(Università della Calabria, 2025-02-28) Mendicino, Federica; Angelone, Tommaso; Bonacci, Teresa
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Marine diatoms as a source of bioactive compounds: bioprospecting and cryopreservation
(Università della Calabria, 2025-02-21) Madeo, Maria Letizia; Angelone, Tommaso; Cozza, Radiana; Romano, Giovanna
Diatoms (Bacillariophyceae) are photosynthetic eukaryotic microalgae that play a key role in ecosystems, accounting for 20-25% of global primary production, approximately 40% of annual marine biomass production (Bhattacharjya et al., 2020). One of their most intriguing aspects is their inter- and intraspecific diversity, both morphological and functional. In recent years, this class of microalgae has emerged as an attractive resource for producing high-value compounds due to their ability to synthesize various bioactive substances (proteins, lipids, polyunsaturated fatty acids, vitamins, pigments, etc.), but also to rapidly increase their biomass, and physiologically adapt to diverse growth conditions (Lauritano et al., 2018; de Jesús-Campos et al., 2020; Cutignano et al., 2022). In this context, the aim of this Ph. D project was to investigate the use of novel diatom species for the production of industrially high-value compounds, such as fucoxanthin, while also evaluating various conditions and techniques for their long-term cryopreservation. One of the aims of this work focused on the study for fucoxanthin production in Thalassiosira rotula, abundant species in the Tyrrhenian Sea with high levels of bioactive compounds (prostaglandins, polyunsaturated fatty acids, xanthophylls). To enhance biomass yield and fucoxanthin content in cultures, two different strains of T. rotula were assessed, and various approaches were applied, including the use of preinocula with varying volumes and abiotic treatments (low light intensity and increased nitrate concentration in the culture medium). Furthermore, through an omics approach in collaboration with the Zoological Station “Anton Dohrn” of Naples, several aspects of treated and untreated cultures were analysed, including morphophysiological variations, photosynthetic pigment content, and the modulation of key genes involved in the fucoxanthin biosynthesis pathway. Considering the potential biotechnological applications of T. rotula, and in general of diatoms, another focus of this project was to test cryopreservation methods on different diatom species. In this context, traditional culture maintenance methods are known to present challenges, such as potential loss or alteration of species characteristics over time, genetic mutations leading to physiological changes and reduced biotechnological relevance, and, importantly, contamination due to repeated handling (Godhe & Rynearson, 2017; Bulankova et al., 2021). In light of this, alternative methods such as cryopreservation are becoming increasingly prevalent in algal culture collections (Stock et al., 2018). However, despite experimental efforts in microalgal cryopreservation, no universal protocol exists (Day, 2007; Tanniou et al., 2012; Buhmann et al., 2013; Kumari et al., 2016). This is closely linked to the inter- and intraspecific variability of these organisms and the diverse stress response mechanisms triggered during cryopreservation, which remain poorly understood. Given the high specificity required for successful cryopreservation techniques, this work evaluated and optimized several parameters, such as incubation time in the cryoprotective agent and freezing methods (rapid freezing or slow cooling freezing), across five different diatom species characterized by size, environmental adaptation, biotechnological potential, and cell cycle stage. Part of the research activities focused on cryopreservation techniques was conducted at Ghent University, within the Protistology and Aquatic Ecology (PAE) laboratories and the BCCM Diatom Culture Collection (BCCM/DCG).
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ENVIRONMENTALMONITORING SYSTEMS AIMED AT DEVELOPING PROTOCOLS FOR HUMAN HEALTH
(Università della Calabria, 2025-02-24) Brunetti, Luana Serafina; Angelone, Tommaso; Indiveri, Cesare; La Russa, Mauro Francesco
Plastic pollution is one of the main global environmental problems of the 21st century. Through the course of the rivers, most plastic waste ends up in the sea, where a slow degradation determines its fragmentation into smaller particles, commonly known as microplastics (MPs) and nanoplastics (NPs). The main problem of the permanence of microplastics in the seas is their ability to interact with aquatic organisms, thus entering the food chain and reaching humans through the consumption of contaminated fish. The toxicity of microplastics is mainly linked to the fact that, during their permanence in the ecosystem, they can absorb and become a vehicle of harmful substances to humans, including pathogenic microorganisms, drugs, antibiotics, and heavy metals. As for heavy metals, some of them are indispensable for normal human biochemical processes, but others, such as lead and mercury, are extremely toxic. SoLute Carriers (SLCs) represent the main target of heavy metals due to their localization on the cell surface. In particular, relevant importance are the organic cation transporters that form a subfamily of the larger SLC22 family because, in addition to the physiological role of transporting endogenous organic cations, are crucial in the disposition of drugs and the interaction with xenobiotics. Among these transporters, OCTN1 appeared in vertebrates during evolution and has homologs in some fishes. Interestingly, OCTN1 harbours seven cysteine residues, already known as a target of a prototype heavy metal, namely mercury chloride. The following study aims to analyze microplastics sampled on the surface of the Mediterranean Sea in six particularly polluted areas of the Calabrian coasts. The size, shape, color, and polymeric composition of the samples have been investigated. Most of the microplastics were very small, with shape and color critical for interactions with biota. In addition, the presence of heavy metals potentially harmful to humans was detected. Subsequently, one of the most important freshwater fish species in the human diet (Oncorhynchus mykiss) has been used as a model for studying the release of these metals from microplastics by the simulation of its digestion process. Interestingly, the release from microplastics of chromium, lead, cadmium, and zinc was significant, especially during the gastric phase of the digestive process, due to the very acidic pH. Lead was also detected by SP-ICP-MS, probably due to solid deposits on the surface of the plastics. Furthermore, the powder obtained from some reference plastic materials showed that the amount of metals released depends on the size of the microplastics and, consequently, on the surface area exposed to the digestive fluids. Finally, the effect of these heavy metals on the human organism was evaluated through interaction studies with the organic cation transporter OCTN1. The potency of heavy metals on OCTN1 was evaluated through IC50 analysis, using the experimental system of the proteoliposome, and the values were in the micromolar range. In addition, the mechanism of interaction of these xenobiotics with the protein was elucidated through site-directed mutagenesis and computational analyses. To suggest some potential scavengers, the effects of some reducing agents were studied. Some of these can reverse the negative effects of heavy metals on OCTN1.