Carnegie Science

Earth and Planets Laboratory

Geochemistry

Biogeochemistry of Chemosynthetic Life: Microorganism Behavior at Different Pressures

Dr. Dionysis Foustoukos

Project Summary

I conducted an independent research project to determine the piezophilicity, or optimal pressure environment, of the deep-sea microbe Nautilia Abyssi. I monitored the levels of nitrogen-based compounds consumed and excreted to determine the pressure at which N. Abyssi functioned most efficiently. These results were presented in an intern symposium and research conference-style abstract.

Skills

Communication: verbal symposium presentation, conference-style abstract

Geochemistry knowledge: nitrogen pathways, thermophilic microbes

Analytical techniques

• Culture assays: cadmium reduction and berthelot reaction method
• Colorimetry
• Isotope-Ratio Mass Spectrometry (IR-MS)

Nitrogen studies

Nitrogen cycling pathways in microbes are crucial to study and provide further context to atmospheric sciences. I examined the metabolic function of a deep-sea microbe using biological assays to assess two nitrate reduction pathways: denitrification and dissimilatory reduction of nitrate to ammonium (DRNA).

Presenting to other scientists

The importance of excluding jargon-even when presenting to other scientists.

In the process of creating my deliverables for this internship, I prioritized defining any terminology I used and avoiding jargon. Although the primary audience was mainly other EPL scientists, many were not researchers in the areas of biogeochemistry. Therefore, I avoided the use of field-specific terms and defined necessary terminology that may be unfamiliar to a general audience.

Contribution to grant-funded projects

My independent research contributed to the broader works of 2 NSF project grants under my mentor.

Collaborative Research: Microbial hydrogen oxidation at high pressure: Role of hydrogenases and interspecies hydrogen transfer

Phase Relations Between Silicate Melts and Crustal Brines

Deliverables

Abstract

The Carnegie EPL SURI program emphasized preparing participants for presenting work at conferences and conducting graduate-level research. In addition to the research symposium, I also created an abstract following research conference guidelines.

Symposium Presentation

The findings of my research were delivered in a research symposium highlighting the works of all seven interns of the Summer 2022 cohort. I presented a 10-minute research talk, followed by five minutes of questions.

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