Microbial Battles: Exploring Inhibitory Interactions Among Sagebrush Bacteria and Fungi

Leaves can harbor diverse communities of endophytic (internal) and epiphytic (external) microbes. Some of these leaf microbes can mediate community interactions by inhibiting the growth of neighboring microbes via antimicrobial compounds. This study investigated the interactions and inhibitory potential of fungal and bacterial isolates derived from sagebrush (Artemisia tridentata) leaves when grown together in co-cultures. Microbes were isolated from the surface and internal sagebrush leaf tissue samples and cultured on nutrient-rich media that supports the growth of a wide variety of bacteria and fungi. Inhibition assays were conducted using co-culture techniques, measuring zones of inhibition to quantify antimicrobial activity. Preliminary results show variation in inhibitory activity among the sagebrush-associated microbes. Some isolates exhibited broad-spectrum inhibition, while others displayed no inhibition. One microbe had large zones of inhibition with certain microbes, but then displayed no inhibitory activity when grown with multiple other taxa, indicating the presence of taxa-specific interactions. This research will provide insights into the potential of sagebrush-associated microbes as a source of novel antimicrobial compounds and highlight the complex interactions within the sagebrush leaf microbiome. Future studies could focus on identifying relevant microbial taxa, their active compounds, and the ecological roles of these antimicrobial interactions.