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Materials and Corrosion 1/2011
Publication year - 2011
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201190000
Subject(s) - desulfovibrio vulgaris , biofilm , extracellular polymeric substance , bacteria , sulfate reducing bacteria , chemistry , sonication , corrosion , microbiology and biotechnology , metal , staining , fluorescent staining , microorganism , concanavalin a , nuclear chemistry , biology , biochemistry , chromatography , organic chemistry , genetics , in vitro
Cover: The effect of microbially influenced corrosion (MIC) due to microbial biofilms is illustrated by the large image: It represents a light‐microscopic picture taken of a specimen of pure iron that was exposed to a culture of Desulfovibrio vulgaris bacteria for 28 days and then treated by ultrasonication in order to remove the adhering biofilm. These sulphate‐reducing bacteria (SRB) quickly adhere on the surface, increase the production of extracellular polymeric substances (EPS) and finally form a biofilm that can exert corrosive impact on the metal e.g. by creating anodic areas beneath the bacterial colonies. In addition, SRB transform mineral sulphates into hydrogen sulphide which is known to be a very corrosive agent. The small image represents a fluorescence‐microscopic picture taken of a sample exposed to Desulfovibrio vulgaris bacteria for three days. The sample was treated by Concanavalin A‐FITC (ConA), a fluorescently labelled lectin that was intentionally applied for staining and visualizing the carbohydrate fractions of EPS covering the sample surface. Bacterial cells also contain carbohydrates in their shell and thus are stained by ConA. In combination, both pictures show the ‘bad guys’ causing MIC and the effect of MIC as well.