Attachment of selenium to a reverse osmosis membrane to inhibit biofilm formation of S. aureus

Previous experiments have shown that when selenium was attached to a surface, biofilm development on the surface was inhibited. Selenium is a catalytic producer of superoxide radicals via oxygen reduction. The superoxide radicals can cause damage to the outer membrane of bacterial cells that frequently results in cell death. Therefore, we propose selenium attachment to an RO membrane surface as a biofouling inhibition technique. Selenium was attached to the surface of RO membranes via monomer (selenocystamine) and polymer (aceto acetoxy ethyl methacrylate) attachment mechanisms. Using confocal microscopy and Staphylococcus aureus cell counting to evaluate S. aureus biofilm growth, the number of attached S. aureus cells was seen to be significantly reduced on RO membranes coated with selenium. While both selenium coatings had similar S. aureus inhibition, the selenium coatings had much different impacts on permeate flux. The selenocystamine attachment method maintained a higher permeate flux compared to the AAEMA attachment method due to AAEMA requiring a harsh attachment procedure. Ultimately, attached selenocystamine showed great potential to serve as a biofouling inhibitor by reducing attached S. aureus growth on RO membranes without excessive permeate flux loss.

► We attach selenium to a reverse osmosis to act as antibiofilm agent.
► Selenocystamine showed both high inhibition without damaging permeate flux.
► Inhibition of S. aureus was seen both visually and using colony counts.
► By limiting biofilm, operating costs of reverse osmosis may be reduced.