Host-Microbe Symbiosis in a Community Context

Symbiosis is the persistent interaction between organisms of different species. Ecological communities grow more elaborate the more organisms there are, meaning microbial communities typically have complex ecological interactions. My project aims to determine the impacts of community context on host-microbe symbiosis, using the insect-parasitic community as a model system. Nematodes, fungi, and bacteria that live in the soil have evolved to use insect larvae as their nutrient source. With so many microorganisms competing for the same nutrient source, competition between these microorganisms is common. The nematode Steinernema is in symbiosis with Xenorhabdus bacteria that assist them in “winning” this competition. We will use microorganisms from different communities to test how the overall community influences the symbiotic relationship between Xenorhabdus and Steinernema. This project will combine expertise on community ecology from Stanford University with expertise on Steinernema-Xenorhabdus symbiosis from the University of Montpellier. This collaboration will allow us to further understand symbiotic relationships and the factors that contribute to changing them, while establishing a model symbiotic system with a manipulatable community that will allow future researchers to ask complex questions about symbiosis and community ecology.