Graduate Program

Biological Sciences

Degree Name

Master of Science (MS)

Semester of Degree Completion

Summer 2023

Thesis Director

Sanghoon Kang

Thesis Committee Member

Thomas Canam

Thesis Committee Member

Scott J. Meiners


Triclosan is an antimicrobial agent that has been used in personal care products and has been identified to cause malformation on cartilage and bone development in zebrafish and influence on thyroid hormone system in humans. Due to its widespread usage and insufficient removal from wastewater treatment plants, triclosan has emerged as a pervasive contaminant that poses a potential threat to the environment and human health. The goal of the study was to isolate and characterize triclosan-degrading bacteria from WWTPs in central Illinois. Using enrichment culture with NMS media containing triclosan as sole carbon source, eighteen bacterial strains were isolated. The 16s rRNA gene sequence analysis revealed that two strains named MAI3 and MAA1 have 99% and 100% similarity with Raoultella and Paraburkholderia respectively. Another two strains named CHI3 and CHA3 have more than 99% similarity with Achromobacter and the rest belong to Pseudomonas within more than 99% similarity. The phylogenetic tree with all 18 strains revealed that there were four distinctive triclosan-degrading bacterial populations from WWTPs in central Illinois. Five of them named CRA1, MAI3, MAE1, CHA3, and CHE1 were found to degrade ~ 80% of initial triclosan concentration in 24 h. The result of this study showed that central Illinois had distinctive bacterial populations that likely have the ability to degrade the triclosan effectively.

Available for download on Friday, August 08, 2025