Assessing the ability of environmental microbes to catabolically degrade the antidepressant venlafaxine (Effexor¨)

Kathryn Clare Sullivan, The College of Wooster

Abstract

Over the last few decades, identification of environmental pollutants has expanded beyond the realm of pesticides, herbicides, and other well-known toxicants such as polychlorinated biphenyls. Pharmaceuticals and personal care products (PPCPs) are increasingly emerging as environmental contaminants. These compounds enter the environment by means of common hygienic practices, human excretion, and improper disposal of expired medications. Although some of these compounds can be removed through wastewater treatment, a significant portion of PPCPs are recycled back into the environment via drinking water and sludge biosolids that are applied to farmland. Environmental accumulation of the antidepressant venlafaxine (Effexor®) has been shown to have an adverse toxicological impact on both aquatic and terrestrial ecosystems. Improving the degradation of venlafaxine during wastewater treatment could be an important step in lessening the burden of venlafaxine in the environment. This research project aims to characterize five environmental microbes, which have previously demonstrated an ability to subsist in minimal media containing venlafaxine. Preliminary LC-MS/MS data indicates a significant decrease in venlafaxine concentration in bacterial culture supernatant over a six-day period; however, methods of scanning for the presence of venlafaxine and its predicted primary metabolites quantitatively were inconclusive. Experimental evidence suggests that in the presence of methanol, microbes are capable of venlafaxine uptake, though their ability to degrade the compound is does not seem likely. Ultimately, this research project provides the groundwork for further exploration of microbial metabolic pathways and degratative enzymes that play a role in environmental PPCP remediation.