Comparison of Growth and Biofilm Attachment of Two Microcystin-Degrading Bacteria to Plasma Polymerized Surface Coatings

There are a growing number of microcystin-degrading organisms that have been isolated; however, their ability to degrade these toxins in an immobilized state within water treatment plant media filters is yet to be explored in detail. Modified polymer coatings were applied to a polystyrene surface through plasma polymerization to determine if biofilm attachment of two previously characterized microcystin-degrading bacteria, LH21 and ACM-3962, were enhanced. Under the experimental conditions, LH21 formed a biofilm [as measured by the specific biofilm formation (SBF) index] on the uncoated polystyrene surface, and attachment was enhanced upon the three polymer coatings, acrylic acid, propionic acid, and allyl amine. Conversely, ACM-3962 was unable to form a biofilm on any surface. This study provides insights into methods that can be used to promote attachment of such organisms to treatment plant filter media, which can ultimately result in greater control and more predictable removal of microcystins. Finally, the methods can be used for screening organisms for their ability to attach to surfaces, a critical process for biofiltration within water treatment plant filters. (C) 2015 American Society of Civil Engineers.