We are looking to recruit an experimentalist PhD student to join our lab to work on one of two projects: (1) controlling species coexistence in microbial communities, and (2) studying division of labour in denitrifying communities. Applicants are also welcome to suggest other topics that are in line with the interests of the lab, and whichever project is agreed upon will be adapted based on discussions.
Project 1: Natural microbial communities are often composed of many different species that stably coexist together over long timescales, exhibiting impressive emergent properties, such as the production of valuable nutrients in the gut or the regulation of the global carbon cycle. Taking inspiration from these and building similar, simpler communities from scratch, would enable and enhance many key technologies, including the degradation of pollutants, the sequestration of greenhouse gases or the production of valuable chemicals. Yet artificially combining environmental isolates to stably coexist in the long term is far from being a predictive science. This project aims to address this challenge: given a set of species, which ones should one combine in what chemical and physical environment to guarantee their long-term coexistence? The student will build a collection of species and characterize their growth and interactions in different chemical environments. Based on these measurements, a mathematical model will predict which species to combine in which environment to achieve stable coexistence. The student will then test these predictions through growth-and-dilution experiments. To deepen our understanding and ability to control these communities, these experiments will be repeated in altered chemical environments to break coexisting communities and fix ones that do not.
Project 2: Nitrous oxide is a potent greenhouse gas that is emitted in high concentrations from wastewater treatment plants and agricultural soil. Nitrous oxide is produced as the last step part of the denitrification pathway, which involves the conversion of oxidized nitrogen compounds to nitrogen gas. Individual steps of this pathway can be performed by many different bacteria in the environment. Such division of labour requires a delicate balance between all involved species, without which the populations of species that perform the last step in the pathway – the removal of nitrous oxide – may collapse, leading to a burst of nitrous oxide production. The goal of this project then is to understand and control this balance, such that the different denitrifying species can coexist together in a way that minimizes nitrous oxide production. The student will begin by constructing a collection of natural isolates that can perform different steps of the pathway. Each will be characterized according to its growth preferences. Using this information coupled with mathematical models developed in the lab, we will predict the conditions that balance the abundances of the different species to minimize nitrous oxide production. These predictions will then be tested in the lab.
You can find more details about the position and apply here before August 31st, 2024 (only applications via the link will be considered)!
