The Effect of a Fullerene Water Suspension on the Growth, Cell Viability, and Membrane Integrity of Escherichia coli B23

Abstract

Fullerenes have been extensively studied for their possible applications in biological, medical, and environmental settings. Recent evidence has shown that fullerene aggregates suspended in water exert a toxic effect on eukaryotic and prokaryotic cells alike. Here we aimed to replicate the antibacterial effect of a fullerene water suspension on Escherichia coli B23, and further intended to determine whether the toxic effect of the fullerene suspension was due to compromised integrity of cellular membrane structures. We utilized three different experiments to evaluate this hypothesis: an assay for growth and viability, a fluorescent staining assay, and an intracellular pH assay. The growth and viability assay confirmed results from previous studies that fullerene aggregates indeed have an inhibitory effect on E. coli B23. However, the fluorescent staining demonstrated that exposure to the fullerene water suspension does not disrupt the structure of cellular membranes. The internal pH assay was inconclusive. Taken as a whole, our results suggest that the antibacterial effect of fullerene on E. coli B23 is not due to damage to the cellular membrane structures, but to other mechanisms that warrant further investigation.