Date of Award

Spring 2021

Degree Type

Restricted Access Honors Project


College of Liberal Arts

First Advisor

Betsy Martínez-Vaz


In the past few centuries, advances in modern technology and medicine have enabled production and development of many useful agriculturally-relevant chemicals and pharmaceutically active compounds. However, this has resulted in the generation and entry of significant amounts of industrial, agricultural, and pharmaceutical waste into environmental surface waters. Little is known of the long-term effect of these environmental contaminants, and many have been shown to be biologically active, causing harm to aquatic life and hastening antibiotic resistance. To investigate the end-fate of several environmentally-relevant nitrogen-rich pollutants, this study employed diverse microbial communities originating from activated sludge and soil by combining classical microbiological, molecular biology, biochemical, and bioinformatic techniques. This study examined a microbial consortia capable of degrading metformin, a common drug utilized in the treatment of type II diabetes, to its transformation product, guanylurea. Enrichment cultures led to the isolation and characterization of a strain of Pseudomonas mendocina capable of degrading guanylurea, and provides the first evidence for the biochemical pathway for guanylurea in microbial species resulting in the formation of guanidine. This study also led to the characterization of a strain of Rhodococcus bacteria, furthering the understanding of microbial guanidine metabolism. This study provides insight into the microbial metabolism of metformin, guanylurea, and guanidine, and could contribute to the development of biotechnological applications for water treatment.








Departmental Honors Projects