Background
Protistan biology was founded by Antonie van Leeuwenhoek’s microscopic observations over 300 years ago. Haeckel, in 1866, proposed the kingdom Protista. These finds have blossomed with the realization that the majority of eukaryotic lineages are composed of mainly single-celled organisms called protists, and that animals, fungi and plants represent just a small fraction of “Eukarya”, our domain of life.
Protists (or microbial eukaryotes) are essential components of every ecosystem. Phototrophs (e.g., microalgae and diatoms) are the counterparts of land plants as main carbon fixers in aquatic systems. Heterotrophs (e.g., flagellates and amoebae) catalyse nutrient cycling in aquatic and terrestrial environments as selective consumers, being critical drivers of the so-called ‘microbial loop’. Protists are natural proxies of community turnover and ecosystem shifts. Anthropogenic disturbances are drastically altering our ecosystem. The polar oceans and aquatic systems in salt flats in Latin America are some hotspots of climate change. The marine arctic ecosystem is anticipated to experience the highest species turnover in terms of invading and locally extinct species. In Latin America, three extensive regions containing Salares (salt flats) in Argentina, Chile and Bolivia together represent the largest global lithium (Li) reserves, commonly referred to as the Lithium Triangle Zone. Due to the increased use of Li as a raw material for batteries of vehicles and electronic devices, these in land aquatic systems have been extensively subjected to mining activities. Efforts to address these crises must be underpinned by biodiversity monitoring and assessment.
Large-scale biodiversity characterization of protist communities across global environmental regions is increasingly reliant on DNA barcoding (or metabarcoding). This methodology uses a fragment of a gene, known as DNA barcode, to survey the taxonomic composition of a given habitat. The barcode identification is based on its comparison to a reference DNA sequence from a described taxon, i.e., a known species. However, most of the diversity captured by metabarcoding cannot be precisely identified at the species level due to the limited numbers of DNA reference sequences originated from known species. The polar oceans and aquatic systems in salt flats in Latin America are at imminent risk, and most of their microscopic species are unknown to science. This gap hampers our ability to detect future changes in protist biodiversity as well as changes in ecosystem structure, dynamics, and functioning in these environments.
What do we want to accomplish?
The main goal of this project is to increase the number of available reference strains and described species from Polar oceans and salt flats in Chile.
How do we want to achieve our goal?
To extend the repertoire of polar and salt flat microbial eukaryotes, we will target for isolation and cultivation species that are formally described but which lack reference DNA barcodes and also cells exhibiting morphologies that do not correspond to any described species. Fresh samples will be obtained through collaboration with the co-advisors of this project from the polar ocean (Arctic and Antarctic) and salt flats in Chile. We will apply several innovative modifications of traditional techniques, including flow cytometry cell sorting combined with multidimensional nutrient gradient ”culturomics” (target single-cells are exposed to multiple growth factors in a gradient micro-plate), microfluidic devices as well as traditional methods such as micropipette picking under an inverted microscope and inhibition of fast-growing microorganisms by blocking agents (e.g., germanium for diatoms).
What will you learn during the Master?
- how to isolate and cultivate protist using high-throughput and classical methods
- how to describe new protist species formally by combining morphological characterization and molecular phylogeny analysis 1
- how to perform and document your analysis with R language and GitHub
- how to write documents using the LaTeX script language
You will have the opportunity to:
- get integrated with PhD-student, postdoc and other Master students participating on distinct projects
- connect with an international network of protist biologists and Microalgae platforms such as the Roscoff Culture Collection (the largest algae culture collection in the world located in France)
What can we offer?
We offer a safe space for learning through achievements and failures, alone and in partnership with others. We welcome individuals of all ages, backgrounds, beliefs, ethnicities, genders, gender identities, gender expressions, national origins, religious affiliations, sexual orientations, and any other visible and non-visible differences. All members of our research groups are expected to contribute to a respectful, welcoming and inclusive environment for every other member.
Supervisors:
Assoc Prof Adriana Lopes and co-supervisor: Assoc Prof Raquel Rodríguez-Martínez (University of Antofagasta, Chile), Assoc Prof Catherine Gérikas (Federal University of Parana, Brazil)