Date of Award

Spring 2015

Document Type

Restricted Thesis

Terms of Use

© 2015 Roxanne K. Morris. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts


Biology Department

First Advisor

Alison Holliday

Second Advisor

Amy Cheng Vollmer


At least, twenty-five percent of the fungicides used had active chiral components, which may be degraded in a chiral manner by chirally biased biological systems. The enantioselective degradation of one enantiomer could lead to bioaccumulation of the other enantiomer; however, its toxicity and half-life are normally tested as racemate. Triazole fungicides are widely used to treat and prevent a broad spectrum of fungal growth such as rust and mildew and have been linked to changes in concentration of sex hormones in mammals. Myclobutanil is a chiral triazole fungicide that has been observed to degrade chirally when applied to agriculture. We hypothesized that soil bacteria, particularly from soil that has been pre-exposed to triazole fungicides, would favorably degrade on myclobutanil enantiomer. The bacteria was grown in the presence of myclobutanil in various soil types and solid media containing various dilutions of Nutrient Broth. Degradation was analyzed by High Performance Liquid Chromatography analysis using chiral and achiral columns. A decrease of myclobutanil concentration of 20 ± 1 ppm was observed after 40 days of incubation, but the degradation did not cause a change in the ratio of enantiomers.