About me

I am a microbiologist specialized in the study of polar microbial communities. My research focuses on the use of molecular ecology methods such as metagenomics and metatranscriptomics to explore the diversity and functional capabilities of microbial communities across the polar regions. I have a MSc degree in Cellular and Molecular Biology from the Federal University of Rio Grande do Sul in Brazil, and a PhD in Sciences from the University of Liège in Belgium. I am currently a Researcher at the Finnish Environment Institute (Syke) in Helsinki, Finland.

I started my journey with polar microbial ecology early in my academic path. Around the final year of my undergraduate studies, I became passionate about the beauty and fragility of the polar regions. Due to my microbiology background—I had been working with fungi as a research assistant since my 2nd year in university–I quickly realised how the protection of polar ecosystems involves studying the invisible microbes living there. After setting up a collaboration to get samples from Antarctica, I was awarded a research scholarship for a master’s degree. My master’s research was very important to me–I took a dive into polar microbial ecology, had my first experience with bioinformatics and wrote my first articles as the leading author (Pessi et al. 2012, 2015). Motivated to continue my polar research, I decided I wanted to improve my bioinformatics skills abroad. This took me first to Belgium for a PhD on the metabarcoding of polar cyanobacteria, and then to Finland, where I have been working since 2018 with the molecular ecology of polar microbiomes. Every step of my academic career has been a turning point, as every change in research topic, methodological approach and country has contributed to both my personal and professional growths.

In my PhD at the University of Liège, I studied the biodiversity of polar cyanobacteria using 16S rRNA gene metabarcoding, which was rather incipient for cyanobacteria at the time. I first worked on the optimization of metabarcoding using primers specific to cyanobacteria (Pessi et al. 2016), a method which I then applied to investigate the biodiversity of cyanobacteria in Arctic and Antarctic aquatic and terrestrial environments (Pessi et al. 2018, 2019; Pushkareva et al. 2015, 2018). In the final year of my PhD, it became evident that metabarcoding is powerful but has two major flaws: it has low taxonomic resolution and provides only indirect and generalized functional data. And so, since moving to Finland–first to work at the University of Helsinki and now at the Finnish Environment Institute-I have switched to genome-resolved metagenomics and metatranscriptomics, which have proven themselves powerful tools for the detailed characterization of the taxonomic and functional diversity of polar microbiomes (e.g. Pessi et al. 2022a, 2022b, 2023, 2024a, 2024b, 2026).

Although science and other types of empirical knowledge are crucial for understanding and mitigating the damages we are causing to us and our only planet, I believe that a better, truly egalitarian society can only be built if we make radical changes to our economic, societal and political systems. The current economic system that has been widely adopted by the Global North is inneficient, destructive, and unsustainable. At the same time, the environmental, societal, and political damages caused by this exploitative system are most felt by those living in the Global South. That is why I believe that the only way forward is through a radical change on how we interact with our planet and each other.

“Ecology without class struggle is gardening”
Chico Mendes, Brazilian trade union leader and environmentalist