Biology Department Seminar Series: Dr. Bahareh Sorouri

Seminar Details

Speaker: Dr. Bahareh Sorouri, NSF Postdoc fellow, University of Alaska Fairbanks

Host: Jen Forbey

Title: Microbial Responses to Perturbation: From Hosts to Ecosystems

Abstract:

The microbiome is an essential part of both host and natural ecosystems, and is required for proper functioning. In hosts, microbes aid digestion and protect against pathogens, while in ecosystems, environmental microbiomes cycle essential nutrients that all living organisms need. My research incorporates multi-omics approaches to understand host-associated and environmental microbial community responses to perturbations. From an ecosystem perspective, anthropogenic influences like pollution and climate change drastically impact the environment, and microbial responses to these phenomena are uncertain. To address this uncertainty, my research explores microbial functional and genetic variation with climate change. I investigated how shifts at microbial taxonomic (genus: Sphingomonas) and community levels influenced function across a Southern California climate gradient. Communities were from five sites that varied inversely with temperature and precipitation (desert, grassland, mountains, etc.) and were reciprocally transplanted in litter bags for 18 months to simulate future climate change conditions. I found that sites had distinct Sphingomonas populations that shifted after the environmental perturbations and led to similar changes within the functional potential. However, extracellular enzyme activity and litter decomposition rates suggested that microbial communities were not specialized to their native environment. Additionally, significant differences in decomposition rates were not related to the enzyme activities that were measured. Currently, I am exploring how the gut microbiome helps herbivorous hosts, including snowshoe hares and Icelandic rock ptarmigan, when they consume toxic or low-quality diets. Preliminary results reflect that both hosts have a high abundance of the Firmicutes bacterial phylum. Additionally, snowshoe hare microbiomes possess diverse genes that facilitate toxin tolerance through cytochrome p450 metabolic pathways and diterpenoid metabolism. Understanding the microbial community response to perturbation at both host and ecosystem levels will help facilitate conservation efforts and inform the impact of climate change in these respective systems.