2024 Undergraduate Research Showcase

Investigating the Growth Dynamics of Sagebrush Leaf Microbes at Different Temperatures

Document Type

Student Presentation

Presentation Date


Faculty Sponsor

Dr. Leonora Bittleston


Understanding the growth dynamics of microbial communities associated with plants is important to understanding their roles in plant health and ecosystem functioning. In this study, we investigated the growth rate of sagebrush microbes cultured in the laboratory over 7 days at different incubating temperatures. Temperature is a major factor that can influence the type of microbes and sometimes their roles in the environment. Our microbes were cultured from sagebrush leaves and stored in a cryo-freezer at -80C as part of a curated database. Therefore, before we started this experiment, we revived three microbial cultures Aureobasidium pullulans, Filobasidium wieringae, and Phaecoccus sp on potato dextrose agar (PDA) which were then subcultured onto a 90 x 15 mm Petri dish to create replicates of monocultures that were incubated at three different temperatures; 4C, 25C, and 35C. These microbes were selected because they are one of the microbial genera that are consistently found on sagebrush leaves throughout the seasons. Daily measurements of microbial growth areas were taken using digital imaging and ImageJ software over time. Our results showed dynamic changes in microbial growth over this period, with distinct growth patterns observed among microbes at different temperatures. Aureobasidium pullulans reached a peak growth at Day 7, Filobasidium wieringae at Day 7, and Phaecoccus sp at Day 7. While there is a slight growth at the 4C, we found that all three organisms are inhibited at 35C with growth at 25C being the optimum temperature for these microbes. Aureobasidium also had the greatest growth rate than the other 2 microbes with Phaecoccis having the slowest growth rate.

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