GENERAL OVERVIEW
The research activity I have been carrying out since January 1, 2022, as part of my PhD in Astrobiology at the Department of Sciences and Technologies of the University of Naples Parthenope (UNESCO chair), is part of a collaborative program between the Department of Biology at the University of Naples Federico II (GiovannelliLab), the Capodimonte Astronomical Observatory (INAF-OAC), and the UK Centre for Astrobiology at the University of Edinburgh. The primary focus of the activity concerns the application of techniques in space environments, specifically within the In-Situ Resource Utilization (ISRU) framework: bioleaching, biohydrometallurgy, and biomining. The latter, successfully tested on the International Space Station (ISS), is becoming an internationally interesting technique for the future of exploration and human settlement on other celestial bodies. One of the potential candidate microorganisms for this type of experiment is Acidithiobacillus ferrooxidans, an extremophilic bacterium capable of living and thriving in hyper-acidic environments highly contaminated with heavy metals (Tonietti et al., 2024).
As part of the collaboration with the University of Edinburgh, I tested the potential use of other organisms capable of mobilizing certain metals of industrial and space interest, such as REE (Rare Earth Elements) and PGE (Platinum Group Elements) (Cockell et al., 2020). I also worked on the selection of terrestrial materials to use as substrates/extraterrestrial analogs: the choice fell on the use of Massive Sulfide Deposits (MSD), collected from "deep-sea hydrothermal vents" along the ocean ridge of the Pacific Ocean by the manned submersible ALVIN, operated by the Woods Hole Oceanographic Institute (US) and the US Navy. These substrates are excellent analogs for the material present in Martian hydrothermal paleolakes, e.g., in Eridania Planitia. I have also analyzed the extractive capabilities of A. ferrooxidans deposited on cryoconites from the Forni Glacier (Alta Valtellina, Italy) to simulate material present on icy moons and in the icy deposits of Mars.
During my visit at the UK Centre for Astrobiology, Edinburgh, to test our hypotheses, I had the opportunity to deposit microorganisms on: 1) meteorites cataloged as originating from the inner asteroid belt, i.e., Eucrites, orig. Vesta; 2) mineral samples from Canada, known for containing rare earth elements and platinum; 3) basalts from Iceland, already used in the BIOROCK and BIO-ASTEROID space missions (Santomartino et al., 2022, Santomartino et al., 2024). The experiments I conducted have provided very promising results for the extraction of key metals of economic and industrial interest, confirming that the techniques I am researching could indeed support the future of space exploration.
Other aspects of my research during the PhD include the study of: 1) the role of transition metals in the evolution of life on our planet; 2) the microbial ecology of extreme environments; 3) light curves acquired by the TESS space telescope for the detection of potential exoplanets; 4) the design of non-invasive pollen and nectar sampling systems; 5) tests of multiparametric data visualization systems; 6) the concept of "freedom" in a space environment; 7) hypothetical xenobiological biochemistries. Finally, I am recently studying how to reconcile certain principles of quantum mechanics with the microbiological world and I am developing a new equation to determine the probability of finding surface life on other planetary bodies, based on the Drake equation.
To support the research activity carried out during the three years of the PhD, I have conducted several campaigns for collecting samples to use as planetary analogs and performed astronomical observations of comets to support the definition of the target for the ESA's Comet Interceptor space mission.
ASTROBIOLOGY
In the field of astrobiology, I primarily focus on the use of microorganisms to support human space exploration. Through the use of extremophiles, I work on in situ resource utilization, specifically in biomining and bioleaching in space environments. Since transporting resources from Earth to other planetary bodies is both ecologically and economically costly, it is necessary to find alternative methods of resource exploitation directly on planetary surfaces.
Specifically, by using acidophilic organisms known for biohydrometallurgy on Earth, I am attempting to extract resources, metals, and more from substrates of planetary analogs. In particular, I am utilizing massive sulfide deposits from deep-sea hydrothermal vents along the East Pacific Rise near Costa Rica, as well as cryoconite samples from the Forni Glacier and meteorites from 4Vesta. These substrates can simulate, under one or more parameters, the surface of Mars, its paleolakes, polar ice caps, and the icy moons such as Enceladus and Europa.
In addition to this I am working to make a new equation to calculate the probability to find life on another planetary surface.
ASTROPHYSICS
In collaboration with the ExoPlaNats group, we focus on the statistical validation of exoplanet candidates, particularly hot Neptunes. Our work with expert colleagues involves applying a two-step vetting technique using tools such as DAVE and TRICERATOPS to systematically analyze transit-like events from the Transiting Exoplanet Survey Satellite (TESS) archive. We specifically investigate candidates within the parameter range of periods less than or equal to 4 days and radii between 3 and 5 Earth radii. Recently, we identified 18 hot Neptune-sized candidates, of which two systems (TOI-277 b and TOI-1288 b) were statistically validated with a false positive probability of less than 0.3%. These validated exoplanets contribute to expanding the known population of hot Neptunes and serve as high-priority targets for future radial velocity follow-up studies.
GEOBIOLOGY
In our collaboration with the GiovannelliLab (UNINA), we explore how life sustains itself by harnessing energy from thermodynamic disequilibria, primarily in the form of redox reactions. Metals play a crucial role in these reactions as they are key components in the biochemical processes that enable metabolism. Despite the critical importance of this topic, the relationship between metals and the redox reactions they facilitate has been insufficiently studied. Our work reviews the structure and function of various prokaryotic organometallic–protein complexes, emphasizing their central role in controlling biogeochemical cycles.
In addition to this I am interested in the geomicrobiology and microbial ecology of mines, acid mine drainages and other extreme environments.
XENOBIOLOGY
I a interest in hypothetical and speculative biology in the realm of xenobiology. Specifically, I like to study potential living entities from movies, science fiction and books. Starting from a scientific point of view I try to reconstruct the zoology, biochemistry, behavior and other science related topics to imaginary organisms, aliens, a fantasy creatures. In the last few months me and a colleague tried to understand the parasitic behavior, the biochemistry, the evolution biology and the terrestrial analogs of the xenomorphs from the "Alien" movie franchise.
ZOOLOGY AND BOTANY
In our study in collaboration with the ZooPlantLab (UNIMIB), we address the global decline of pollinator insects, which is partly due to changes in their diet that have serious implications for their health. Since pollinators rely mainly on flower rewards such as pollen and nectar, accurately characterizing their chemical composition is essential for understanding pollinators' nutritional ecology. Pollen, in particular, presents challenges for study due to difficulties in collection and the small amounts produced per flower.
To address this, we developed and tested a novel, easy-to-assemble pollen sampling tool called E-PoSa (Electronic Pollen Sampler), which utilizes a portable vacuum cleaner. We compared E-PoSa with commonly used sampling methods (such as anther sieving and whole anther sampling) to assess differences in pollen recovery rates and nutritional profiles. Additionally, we evaluated its applicability in ecological studies by testing its recovery rate across a variety of wildflower species in field conditions.
Our results showed that E-PoSa significantly outperforms the conventional sieving approach in pollen recovery and successfully collects enough pollen for phytochemical analysis across diverse flower morphologies. Furthermore, E-PoSa collects high-purity pollen without introducing any significant variation in nutritional analysis compared to conventional methods. This new sampling tool offers an affordable and easy-to-use solution, encouraging its use in pollen nutrition studies and various other contexts related to pollination ecology. By promoting standardized field protocols, our approach can enhance the understanding of species interactions, foraging patterns, and the nutritional needs of pollinators.
COMPUTATIONAL CHEMISTRY
During my master-thesis, I employ quantum-mechanical methods (DFT) to study the movement of electrons and the conformational changes that can occur at the fine structural level of metal cofactors in enzymes. My focus is particularly on V-Nitrogenases and their unique metal cofactor, known as FeVco. This cofactor plays a critical role in the reduction of atmospheric nitrogen (N₂) and carbon dioxide (CO₂) to ammonium ions (NH₄⁺) and hydrocarbons, processes essential for nitrogen fixation and carbon cycling in nature.
I explore how the electronic structure and dynamics of FeVco enable these complex chemical transformations, delving into the specific electronic pathways and molecular rearrangements that facilitate the binding and reduction of substrates.
PHYLOSOPHY OF ASTROBIOLOGY AND SPACE EXPLORATION
In a hypothetical future where interstellar travel is both possible and affordable, I explore the potential implications of infinite resources and the universalization of freedom on both societal and individual levels. I argue that freedom represents the ultimate goal of human emancipation and the highest purpose of history, embodying the idea of infinite and indefinite progress in both historical and scientific contexts.
I also examine Bakunin's critique of contractualism, which challenges the notion of a mythical, primordial natural freedom that supposedly existed before the formation of society. This analysis includes an exploration of the romantic cultural underpinnings that influence Bakunin's anarchist thought, emphasizing the profound emotional and philosophical foundations of his ideas.
I underscore the importance of the concept of freedom in the context of future space travel, suggesting that the expansion of humanity into the cosmos could fundamentally transform our understanding of liberty and progress.
BIOPHYSICS
During my bachelor thesis I was working on the biophysics of prebiotic processes studying the origin of life from the point of view of amyloid. Instead of the RNA and the DNA theory about the origin of life I focus my attention in regard to these shorts amino-acidic sequences that are able to self-replication and carrying a sort of information.
