Microbial Communities Around Us: Insights into Microbial Response and Resistance

Abstract

This thesis will discuss two research projects. Both projects aim to examine microbial communities that exist around us, within distinct settings. The first will focus on microbial communities in an agricultural setting, with a focus on antibiotic resistance and a more local perspective. The second will focus on the inhibitory effect of Sphagnum moss leachates (i.e. antimicrobial compounds secreted by Sphagnum) on organisms from three different ecosystems, through a more global perspective. Both projects contribute to areas of research that are indispensable, due to their impacts on our daily lives and their implications for our future. The first project studies the levels of antibiotic resistant bacteria on organic vs. non-organic vegetable produce, which is relevant to human health and food consumption. The second studies the influence of Sphagnum moss leachates on microbial activity, and thus the release of greenhouse gasses such as carbon dioxide and methane, which is relevant to climate change. Project 1 found that there were antibiotic resistant bacteria present on both organic and non-organic varieties of three vegetable types (red beets, romaine lettuce, and carrots). The results added to the knowledge of antibiotic resistance in agriculture and indicated the need for consumers to wash all produce thoroughly before consumption regardless of which farming practice was used to grow them. Project 2 found that soil microbial communities from a desert, tropical rainforest, and peatland ecosystem each had a unique response to the addition of Sphagnum leachate and that Sphagnum’s antimicrobial compounds were likely not the only factor contributing to microbial inhibition in peatlands.