Team

I culture representative isolates of dominant groups of oligotrophic marine bacteria (e.g. SAR11, Verrucomicrobia) that we have isolated from the Eastern Mediterranean Sea to study their physiologic and genomic adaptations to the ultra-oligotrophic conditions typical of this marine region. Further, I work on sponge bacterial isolates that contain gene clusters involved in the production of secondary metabolites, to determine the growth conditions that regulate the expression of genes of biotechnological interest. 

Rhodopsins have been reported as the most abundant phototrophy strategy in bacterioplankton cells, especially in oligotrophic regions of the ocean. However, the rhodopsin-related physiology in different taxonomic groups of bacteria remains understudied. During my Ph.D. I will work with different strains of photo-heterotropic bacteria in order to identify how rhodopsins affect their physiology and contribute to the understanding of the role of these molecules on a global scale. Further, I am interested in studying the potential for methane production via demethylation of organic compounds found in dissolved organic matter, both in nitrogen- and in phosphate-depleted environments of the surface ocean. Personally, I'm interested in Bioinformatics, techniques of Molecular Biology and scientific diving. 

Building upon previous research in our lab indicating that certain symbionts have the genetic potential to metabolize organic compounds while releasing methane (Ramírez et al. Microbiome 2023), my research focuses on experimentally validating and quantifing this metabolic activity. In conduct incubation experiments using sponge tissue with isotope-labeled substrates to monitor the release of 13CO₂ or 13CH₄ from various organic 13C-substrates. The long-term objective is to assess the balance between methane production and consumption within sponge holobionts, thereby determining their role as either methane sources or sinks in marine ecosystems. 

After a Master's program, in which I studied phosphonate cycling in the numerically dominant bacteria in global surface oceans, SAR11, in my PhD, I am continuing to investigate SAR11’s potential role in global warming via methyl phosphonate biosynthesis and degradation. Methyl phosphonates are a source of phosphate for bacteria when inorganic phosphate is limited, and release methane, a potent greenhouse gas. I postulate that some SAR11 strains are responsible for most of the MPn biosynthesis in the ocean. My aim is to test this hypothesis and investigate what environmental conditions trigger MPn biosynthesis. As a hobby, I am the photographer, also in our lab events