title: Anticorrosive influence ofAcetobacter acetibiofilms on carbon steel.
abstract: Microbiologically influenced corrosion (MIC) of carbon steel infrastructure is an emerging environmental and cost issue for the ethanol fuel industry, yet its examination lacks rigorous quantification of microbiological parameters that could reveal effective intervention strategies. To quantitatively characterize the effect of cell concentration on MIC of carbon steel, numbers of bacteria exposed to test coupons were systematically controlled to span four orders of magnitude throughout a seven-day test. The bacterium studied,Acetobacter aceti, has been found in ethanol fuel environments, and can convert ethanol to the corrosive species acetic acid.A. acetibiofilms formed during the test were qualitatively evaluated with fluorescence microscopy, and steel surfaces were characterized by scanning electron microscopy. During exposure, biofilms developed more quickly, and test reactor pH decreased at a faster rate, when cell exposure was higher. Resulting corrosion rates, however, were inversely proportional to cell exposure, indicating thatA. acetibiofilms are able to protect carbon steel surfaces from corrosion. This is a novel demonstration of corrosion inhibition by an acid-producing bacterium that occurs naturally in corrosive environments. Mitigation techniques for MIC that harness the power of microbial communities have the potential to be scalable, inexpensive, and green solutions to industrial problems.
authors.affiliation: National Institute of Standards and Technology, Boulder, CO, USA.
authors.forename: Danielle Cook
authors.initials: DC
authors.lastname: France
keywords: Acetobacter aceti; Microbiologically influenced corrosion; biofilms; carbon steel; corrosion inhibition; ethanol