Elucidating the Effect of Graphene Oxide and Other Nanoparticles on the Growth of Gram-Negative Bacteria

Undergraduate #137
Discipline: Technology and Engineering
Subcategory: Nanoscience

Kalah Ozimba - Howard University

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Bacteria are found in both natural and man-made environments. They can grow as either planktonic cells or biofilm cells. Planktonic cells are the free floating bacteria in suspension during growth. Biofilms are the cells that adhere to surfaces as slimy, glue-like substances. Pseudomonas aeruginosa is a common gram-negative bacterium that can cause disease in animals and humans. It is found in soil, water, and most manmade environments. Vibrio cholerae is a comma shaped gramnegative bacteria. It is responsible for cholera, an acute diarrheal disease that can kill within hours if left untreated. Both P. aeruginosa and V. cholerae can grow as either planktonic cells or biofilm cells. Nanoparticles are utilized for a variety of tasks in today’s society. Graphene oxide (GO), for instance, has been explored as one of the most promising nanomaterials with biomedical applications. Thus far, properties of graphene oxide have been useful in the fields of advancing drug delivery systems, therapeutics, and much more. In this research, we hypothesize that GO and similar nanoparticles in concentrations relevant to environmental settings could interfere with bacterial growth. P. aeruginosa and V. cholerae serve as model pathogens. Bacterial growth is monitored by measuring optical densities and/or fluorescence of cells in culture. Preliminary data suggest graphene has properties that limit the growth of P. aeruginosa. Activity against V. cholerae has yet to be investigated. Elucidating the effects of GO nanoparticles on bacterial growth may have significant relevance in understanding the environmental and biological impacts of these new nanomaterials.

Funder Acknowledgement(s): This research was supported in part by the WBHR-LSAMP Program, which is funded by the National Science Foundation (NSF HRD-1000286). Nanoparticles were provided by Dr. Kimberly Jones, from the Department of Civil and Environmental Engineering at Howard University. All experiments were performed in the Biofilm Engineering and Drug Discovery research laboratory, located in the Department of Chemical Engineering at Howard University, under the supervision of Dr. Patrick Ymele-Leki.

Faculty Advisor: Patrick Ymele-Leki,