Professor Audie Thompson of the University of Arkansas will give a seminar titled "Microcystin-LR removal from water via enzymatic linearization and ultrafiltration" on Zoom from 3:30-4:30 p.m. Friday, April 8. Everyone is welcome to attend the seminar individually via Zoom or to come to CHEM 144, where the seminar can be viewed in person with other attendees. The talk is free and open to the public.

Thompson is an assistant professor in the Ralph E. Martin Department of Chemical Engineering here at the U of A. Her research investigates remediation strategies for microcystin-tainted water by combining linearization of microcystin (MC-LR) to a low-toxicity byproduct and removal by membrane filtration. Current global outbreaks of cyanobacterial blooms are due to the emergence of their toxic byproducts. MC-LR, a hepatotoxin, is considered the most toxic byproduct because it bioaccumulates and biomagnifies in aquatic environments leading to adverse side effects in higher-order organisms. It has been associated with inhibiting protein phosphatases, disrupting the formation of the cytoskeletons, promoting oxidative stress, and liver tumors leading to liver cancers.

Thompson's group has used an enzyme, MlrA, to linearize MC-LR, followed by ultrafiltration with a composite 5% polysulfone and 5%sulfonated polyether ether ketone (SPEEK) membrane. Tests were also performed to measure the adsorption and desorption of MC-LR on polysulfone/SPEEK membranes. Liquid chromatography-mass spectrometry (LC-MS) was used to characterize the progress of linearization and removal of MC-LR.

Results indicate that the MlrA was successful at linearizing MC-LR. Membrane filtration tests rejected 97% of cyclic MC-LR and virtually all linearized MC-LR, with adsorption to the membranes being the primary rejection mechanism. Adsorption/desorption tests indicated that methanol could be used to strip residual MC-LR from membranes to regenerate them. The results showed that coupling the two systems can facilitate the recyclability of the enzyme and enhance enzyme properties such as viability and stability.

To attend the seminar, please visit the Zoom link.

• Meeting ID: 837 3375 9275
• Passcode: Two+Two=5