Biofilm formation of Desulfovibrio alaskensis G20 (DA G20) on 2-Dimensional Materials

Author: Juneau Jones, Department of Civil and Environmental Engineering and 2-Dimensional Materials for Biofilm Engineering, Science and Technology (2D-BEST)

Mentor: Dr. Suvarna Talluri, Department of Civil and Environmental Engineering and 2-Dimensional Materials for Biofilm Engineering, Science and Technology (2D-BEST)

Mentor: Dr. Venkata Gadhamshetty, Department of Civil and Environmental Engineering and 2-Dimensional Materials for Biofilm Engineering, Science and Technology (2D-BEST)

Microbiologically induced corrosion (MIC) or biofouling occurs when microorganisms interact with the metal surfaces and form biofilms. Several different fields such as power plants, marine infrastructure, petrochemical industries, and refineries have been affected by MIC. Sulfate reducing bacteria are one of the dominant group of bacteria that are known to damage the structural integrity of metals such as steel, copper etc. by inducing corrosion. The US Navy spends approximately $1 billion every year to address the MIC issues caused by sulfate-reducing bacteria. Recently, atomic layers of 2D graphene materials have been explored for corrosion prevention of metals from sulfate reducing bacteria. With a goal of understanding the corrosion and biofouling behavior of a model SRB, Desulfovibrio alaskensis G20 (DA G20) on single layer graphene coated polycrystalline copper substrates, an experimental method was developed. DA G20 biofilms formed on bare polycrystalline copper (Bare-PC Cu) and single layer graphene coated polycrystalline copper (SLG-PC Cu) over a period of 7 days were compared and analyzed by confocal laser scanning microscopy and atomic force microscopy. Physicochemical characterization of bare-PC Cu and SLG-PC Cu substrates was done by AFM and Raman spectroscopy. The integrity of SLG-PC Cu substrate over 7 days during the biofilm formation of DA G20 was assessed by Raman spectroscopy. Qualitative analysis of confocal laser scanning microscope and AFM images revealed that the biofilm coverage was more on SLG- PC Cu than on bare-PC Cu substrate. Our future work will focus on evaluating the biofilm formation of DA G20 on few layer and multilayered graphene deposited on single and polycrystalline copper substrates. The experimental method developed could be applicable to study the biofouling of other anaerobic microorganisms on any metal substrates that are prone to microbiologically induced corrosion.

Keywords: Microbiologically induced corrosion (MIC), Biofouling, Sulfate reducing bacteria, Graphene, Atomic force microscopy, Raman spectroscopy