Professor Audie Thompson of the University of Arkansas will give a seminar titled “Removal of Microcystin-LR from Water via Enzymatic Linearization and Ultrafiltration” on Zoom from 3:30 p.m. to 4:30 p.m. on Friday, April 8. Everyone is welcome to attend the seminar individually via Zoom or come to CHEM 144, where the seminar can be viewed in person with other attendees. The conference 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 focuses on strategies for remediating microcystin-contaminated water by combining microcystin linearization (MC-LR) into a low toxicity by-product and its disposal. by membrane filtration. Current worldwide epidemics of cyanobacterial blooms are due to the emergence of their toxic by-products. Microcystin-LR, a hepatotoxin, is considered the most toxic byproduct because it bioaccumulates and biomagnifies in aquatic environments, causing unwanted side effects in higher order organisms. It has been associated with inhibition of protein phosphatases, disruption of cytoskeletal formation, promotion of oxidative stress, and liver tumors leading to liver cancers.

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

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

To attend the seminar, please visit the Zoom link.

• Meeting ID: 837 3375 9275
• Access code: Two+Two=5