I-Corps: Antimicrobial polyvinyl chloride (PVC) pipe to reduce biofouling in hydroponic farming

The broader impact/commercial potential of this I-Corps project is the development of a antimicrobial polyvinyl chloride (PVC) pipe that can inhibit biofouling by bacteria for the agriculture industry. Currently, polyvinylchloride (PVC) is the predominant material used for tubing and nutrient beds thanks to its cheap cost and environmental resistance. However, farms must either regularly dissemble and clean PVC components or replace them altogether, since the regular use of biocides does not prevent biofouling. The goal is to reduce the cleaning and maintenance required in micro/drip irrigation and hydroponic farms, saving costs, and improving productivity. Bacteria are able to grow on most plastic surfaces as there are few approved antimicrobial alternatives. The proposed technology is designed to include antimicrobial materials embedded into PVC that are safe for use in agriculture and could save US farmers significant time and money every year. This I-Corps project is based on the development of a bismuth oxide nanomaterial that may be used as a broad-spectrum antimicrobial agent. The goal is to treat PVC pipe by embedding the bismuth oxide nanomaterial or using it as a coating for use in agricultural applications. Although antimicrobial surface treated PVC tubing is available, the high cost has prevented widespread adoption and no antimicrobial PVC materials are currently approved for food production by the FDA, EPA, or state entities. Bismuth, unlike other antimicrobial metals such as mercury, lead and cadmium and many others, is known to be nontoxic to mammalian cells, and may be safely ingested at gram-scale quantities. Tests of the proposed nanomaterial showed that nanostructured bismuth oxide was found to be a broad-spectrum antimicrobial agent as shown by its minimum inhibitory concentration, which ranges from 0.75 μg/mL to 2.5 μg/mL, depending on the bacteria tested. In addition, a strong growth inhibitory effect also was found on methicillin-resistant Staphylococcus aureus (MRSA) derived biofilms. The proposed technology may show similar efficacy in agricultural settings since bismuth oxide nanomaterials are not limited to targeting bacteria-specific proteins like most antibiotics. Also, bismuth oxide nanomaterials do not behave like any conventional antibiotics in that they do not trigger the rapid development of drug resistance like the conventional antibiotics. The lack of available and agriculture approved antimicrobial polymers presents a current unmet need, and use of new antimicrobial materials embedded into PVC may save US farmers significant time and money. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.