Date Thesis Awarded
5-2024
Access Type
Honors Thesis -- Access Restricted On-Campus Only
Degree Name
Bachelors of Science (BS)
Department
Neuroscience
Advisor
Margaret Saha
Committee Members
Greg Conradi Smith
Mark Forsyth
Dana Willner
Abstract
Synthetic Biology has shown potential to address soil degradation and climate change through the design of microbes that can, for example, degrade pollutants, sequester greenhouse gasses, and increase crop yields. For Synthetic Biology to be a realistic solution, bioengineered bacteria must be able to survive, spread, and express genes of interest in soil environments. However, major gaps in knowledge exist about how inoculated bacteria behave in the soil.
This project takes three foundational steps toward fieldable soil synthetic biology. First, a soil microcosm experiment was conducted with engineered Mycobacterium smegmatis over 49 days, the first of its kind to incorporate bacteriophage, have a spatial component, and compare population dynamics across bacterial engineering methods as well as soil sterility. This experiment demonstrated the ability of bacteria, regardless of engineering type and soil sterility, to persist in soil. It also revealed statistically significant differences in bacteria and phage population dynamics over time across bacterial engineering types and soil sterility. Second, a Polycyclic Aromatic Hydrocarbon (PAH) pollutant degradation circuit was designed and constructed, and then integrated into M. smegmatis’s genome. And, third, an RNA extraction protocol was optimized for the simultaneous extraction of RNA from culture and from soil, which will enable RNA sequencing experiments comparing gene expression between these two environments.
Recommended Citation
Fleeharty, Megan, "Bringing Synthetic Biology from the Flask to the Soil (Microcosm)" (2024). Undergraduate Honors Theses. William & Mary. Paper 2128.
https://scholarworks.wm.edu/honorstheses/2128
