Date of Submission

Spring 2016

Academic Programs and Concentrations

Division of Science, Mathematics, and Computing

Project Advisor 1

Gabriel Perron

Abstract/Artist's Statement

Triclosan (TCS), an antimicrobial agent incorporated into a wide range of consumer products including soaps, detergents, cleansers, toothpastes, and deodorants, has been detected in numerous aquatic ecosystems across the United States. The majority of TCS (95%-99%) is removed from waste water by degradation or absorption to sludge, while the remainder is released from the waste water treatment plant (WWTP) as effluent. The TCS released from the WWTP is found in surface water and accumulates in sediments. Field studies have demonstrated that there is a significant correlation between TCS in sediments and the prevalence of TCS resistant bacteria, demonstrating that TCS exposure is affecting bacterial communities. In this study, we used 16S metagenomics to explore the effect environmentally relevant concentrations of TCS have on microbial community composition of surface water samples from the Sawkill Creek, a tributary of the Hudson River. We found that exposure to TCS significantly decreases the diversity of the microbial communities in the water samples and significantly shifted the bacterial community composition. We found that sampling site and treatment did not have a significant effect of the change in the proportion of TCS resistant bacteria; however, all samples from the Sawkill contained TCS resistant bacteria before treatment. Although TCS resistance was not significantly affected, Pseudomonas and Arcobacter are two genus of bacteria with pathogenic species that clustered closest to treated samples. These results suggest that if this compound is not more heavily regulated, it could potentially pose an enormous risk to both environmental stability and public health.

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