Microbially influenced corrosion microorganisms

Sulfate-reducing bacteria (SRB) are some of the most common and problematic microorganisms of environmental and economic importance in petroleum industry. The effects caused by SRB activity are mainly the souring of oil and gas deposits and in problems related with microbially influenced corrosion (MIC). The toxic hydrogen sulfide produced may also present a health hazard to workers and may decrease oil quality by the souring of oil and gas [1],... 

Microbially influenced corrosion (MIC) is, by definition, corrosion associated with the action of microorganisms present in the system. Microbially influenced corrosion is therefore an interdisciplinary subject that embraces the fields of materials science, chemistry, microbiology, and biochemistry. 

The main purpose of this chapter is to provide an overview of present knowledge of the mechanisms of microbially influenced corrosion on common constructional materials. This review includes both metallic and nonmetallic materials. The reason for including nonmetallic materials is that biodegradation occurs on these materials and that they are widely used for constmction purposes. Because detailed knowledge in the fields of microbiology and biochemistry is necessary in order to understand the mechanisms of microbially influenced corrosion, considerable space has been devoted to a general description of microorganisms and to a... 

In summary, it becomes obvious that most reactions of materials with the environment are influenced by microorganisms and are often even controlled by them [36]. Thus, in the case of microbially influenced corrosion, the participation of microoiganisms needs to be anticipated [54,95]. Furthermore, cases are known in which excreted metabolic products, e.g., EPS free from microbial cells, cause corrosion. 

A. Chamberlain and P. Angell, Influences of microorganisms on pitting of copper tube, Proceedings Microbially Influenced Corrosion and Biodeterioration (N. J. Dowling, M. W. Mittleman, and J. C. Danko, eds). University of Tennessee, Knoxville, 1990, pp. 3/65-3/69. 

Microbiologically influenced corrosion is defined by the National Association of Corrosion Engineers as any form of corrosion that is influenced by the presence and/or activities of microorganisms. Although MIC appears to many humans to be a new phenomenon, it is not new to the microbes themselves. Microbial transformation of metals in their elemental and various mineral forms has been an essential part of material cycling on earth for billions of years. Some forms of metals such as reduced iron and manganese serve as energy sources for microbes, while oxidized forms of some metals can substitute for... 

The sheer complexity of the corrosion process in the presence of microoiganisms and microbial biofilms makes data interpretation difficult. Thus, whenever possible, multiple techniques should be used for assessing any microbial corrosion situation before conclusions are drawn. An outline of the laboratory techniques used most successfully in the past, along with any cautions for applying those techniques when the corrosion is influenced by microorganisms will be given below. 

Bacteria, fungi, and other microorganisms can play a major part in soil corrosion. Spectacularly rapid corrosion failures have been observed in soil due to microbial action and it is becoming increasingly apparent that most metallic alloys are susceptible to some form of microbiologically influenced corrosion (MIC). 

Microorganisms are involved in the corrosion of metal and the degradation and deterioration of polymers, concrete, and stone under both aerobic and anaerobic conditions. They may influence the surface electrochemical properties, resulting in corrosion of metals under aerobic conditions, and induce hydrogen embrittlement by microbial production of hydrogen. Indirectly, degradation and deterioration of metals, stone, and concrete are... 

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