Effect of Rock Surfaces on the Corrosion Capability of Yucca Mountain Bacteria Available to Purchase

The current research investigated whether the presence of a rock surface enhanced the ability of test microorganisms to survive elevated temperature and corrode carbon steel (CS). Microorganisms implicated in microbiologically influenced corrosion, in a combined consortium, were inoculated into an electrochemical cell composed of a 1020 CS coupon immersed in either soft agar or a mixture of sterile rock and soft agar prepared with simulated groundwater. Uninoculated electrochemical cells were prepared to monitor abiotic corrosion. Initial and weekly corrosion rates were obtained for the duration of the experiment. Upon completion of the experiment, exposed coupons were prepared for phospholipid fatty acid and microscopic analyses to assess microbial biomass and mineralized biofilm formation. Increased biomass and higher corrosion rates were observed in the R2A/rock microcosms. The results of this investigation show that a rock matrix enhances corrosion rates, biofilm formation, and the ability of these microorganisms to survive at elevated temperatures.