This project generated the first results of Cd exposure impacts on deep-sea bacterial isolates (Pizarro et al., 2023). Moreover, the data generated from all the experiments (still to be analysed) will generate the first results on Cd and Cu effects on N2O metabolism, gene expression and overall transcriptome, as well as on genetic and functional diversity of deep-sea sediments.
This research presents significant scientific and societal impacts. Regarding the scientific impacts the following can be highlighted:
- Even though several studies have quantified the toxicity of metals to organisms from all domains of life in different environments, very few studies have quantified this toxicity in deep-sea substrates or under deep-sea conditions. By performing shipboard exposure experiments with freshly collected deep-sea samples and by replicating deep-sea conditions using high-pressure bioreactors , this project represents a novel approach towards understanding metal toxicity in the deep ocean.
- Besides evaluating the metal exposure impacts on overall microbial diversity, the MIDFun project is investigating the impacts on specific functional diversity (e.g. N cycling transformations, biosynthetic gene clusters, etc.), which has implications for diverse scientific fields, from biogeochemistry to marine biotechnology. Moreover, this project will evaluate the effects of increased metal exposure on a process with global impacts on the climate: microbial production of N2O, an important greenhouse gas and a major disruptor of the ozone layer.Despite microbial in nature, the scientific impacts of our findings will be “macroscopic”, due to the environmental importance of the studied phenomena and the magnitude of the deep ocean.
- The methodological approach used combines the application of pure cultures and complex communities, which is not commonly performed in environmental microbiology studies. This approach will allow the project to explore mechanistic subcellular processes as well as evaluate their contribution to the overall outcomes from more realistic communities. The metagenomic and transcriptomic analyses will also target diverse metabolic pathways, including metal resistance and nitrogen metabolism. This approach will generate information about the cellular mechanisms responsible for a potential metal effect on the functional genetic capacity of the microbial models.
Besides the scientific impacts, this research project also presents significant societal impacts:
- This research will contribute to improve understanding of the multiple roles that deep-sea microbial communities play in the in ocean as well to investigate potential impacts of mining on microbial diversity and ecosystem services, thus contributing to better inform future decisions regarding deep seabed management.
- The findings from this project will also be particularly timely, with the recently completed UN’s High-Seas Treaty and the ongoing negotiations at the International Seabed Authority (ISA) for the first regulations of commercial mining in international waters. Our specific societal audience are the members of the ISA’s Intersession Expert Groups as well as ISA’s Legal and Technical Commission, tasked with developing binding environmental thresholds for suggested standards and guidelines for the mining activities.
