Protocol for Evaluating the Biological Stability of Fuel Formulations and Their Relationship to Carbon Steel Biocorrosion

The microbial metabolism of conventional and alternative fuels can be associated with the biocorrosion of the mostly carbon steel energy infrastructure. This phenomenon is particularly acute in anaerobic sulfate-rich environments. It is therefore important to reliably assess the inherent susceptibility of fuels to anaerobic biodegradation in marine waters as well as provide a measure of the impact of this metabolism on the integrity of steel. Such an assessment of fuels is increasingly important since the exact chemical makeup of both traditional and biofuels can vary and even subtle changes have a profound impact on steel biocorrosion. Herein, we describe a simple protocol involving the incubation of carbon steel coupons in seawater under anaerobic conditions. The increased depletion of sulfate in fuel-amended seawater incubations relative to both autoclaved and fuel-unamended negative controls is monitored as a function of time. We also recommend the incorporation of a known hydrocarbon-degrading sulfate-reducing bacterium as a positive control in the assay to verify that the protocol is not predisposed to failure for unrecognized reasons. At the end of the incubation, corrosion is assessed by both coupon weight loss and a mass balance of the total iron released. Lastly, three-dimension noncontact profilometry is used to assess the degree of damage (e.g., pitting) to the coupons. The integration of the interdisciplinary approaches in this protocol allows for a critical asse...
Source: Springer protocols feed by Microbiology - Category: Microbiology Source Type: news