Dr. Marhuenda-Egea began his research career under the direction of Dr. Cadenas, working in halophilic enzyme systems in organic solvents. This research in Biotechnology allowed the development of new protocols to work with enzymes in non-biological systems. Later, he worked in Molecular Biology, employing extreme halophile archaeas as a research target. Dr. Marhuenda-Egea worked in sequencing and transformation of archaea. He made postdoctoral stays at the University of Florence, under the direction of Dr. Bertini. Subsequently, his work has focused on Metabolomics, specializing in various intrustrumal techniques such as MRI (Nuclear Magnetic Resonance), Fluorescence Spectroscopy, FT-IR (Fourier Transform Infrarred), Thermal Analysis and HPLC-MS (High Pressure Liquid Chormatography with Mass Spectroscopy). Currently, he focuses his research on different systems, ranging from human fertility to the study of organic matter in natural systems. Another particularly interesting line of research is the focus on aquatic systems, covering both the study of marine environments and fish communities.