About me

I am a microbiologist specialized in the study of polar microbial communities. My research focuses mostly 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 (UFRGS, Brazil), and a PhD in Sciences from the University of Liège (Belgium). I am currently a Researcher at the Finnish Environment Institute (Syke) (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 two 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 metabarcoding of polar cyanobacteria, and then to Finland, where I have been working for the past six years with metagenomics of polar ecosystems. Every step of my academic career has been a turning point, as every change in topic, approach and country has contributed to both my personal and professional growths.

In my PhD, I studied the biodiversity of polar cyanobacteria using 16S rRNA gene metabarcoding, which was surprisingly 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 was powerful but had two major flaws: it provides low taxonomic resolution and only indirect and generalized functional data. And so, I have since switched to genome-resolved metagenomics, a modern approach that has allowed me to characterize in detail both novel taxonomic and functional diversity of polar microbes (Pessi et al. 2022a, 2022b, 2023, 2024).

Although science and other types of empirical knowledge are crucial for understanding and mitigating the damages we are causing to our planet and the lives of its inhabitants, I strongly believe that our future depends on radical changes to our economic, societal, and political systems. The current economic system adopted by the so-called "developed countries" of 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 each other and the environment.