title: Control of metallic corrosion through microbiological route.
abstract: Involvement of biofilm or microorganisms in corrosion processes is widely acknowledged. Although majority of the studies on microbiologically induced corrosion (MIC) have concentrated on aerobic/anaerobic bacteria. There are numerous aerobic bacteria, which could hinder the corrosion process. The microbiologically produced exopolymers provide the structural frame work for the biofilm. These polymers combine with dissolved metal ions and form organometallic complexes. Generally heterotrophic bacteria contribute to three major processes: (i) synthesis of polymers (ii) accumulation of reserve materials like poly-beta-hydroxy butrate (iii) production of high molecular weight extracellular polysaccharides. Poly-beta-hydroxy butyrate is a polymer of D(-)beta-hydroxy butrate and has a molecular weight between 60,000 and 2,50,000. Some extracellular polymers also have higher molecular weights. It seems that higher molecular weight polymer acts as biocoating. In the present review, role of biochemistry on corrosion inhibition and possibilities of corrosion inhibition by various microbes are discussed. The role of bacteria on current demand during cathodic protection is also debated. In addition, some of the significant contributions made by CECRI in this promising area are highlighted.
authors.affiliation: Electrochemical Protection & Biofouling Section, Corrosion Science & Engineering Division, Central Electrochemical Research Institute, Karaikudi, 630 006, India. marutha_m@yahoo.com
authors.forename: S
authors.initials: S
authors.lastname: Maruthamuthu
authors.forename: S
authors.initials: S
authors.lastname: Ponmariappan
authors.forename: S
authors.initials: S
authors.lastname: Mohanan
authors.forename: N
authors.initials: N
authors.lastname: Palaniswamy
authors.forename: R
authors.initials: R
authors.lastname: Palaniappan
authors.forename: N S
authors.initials: NS
authors.lastname: Rengaswamy
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D018441:Biofilms; D003343:Corrosion; D004563:Electrochemistry; D007218:Industrial Microbiology; D013232:Steel / Q000737:chemistry*
chemical_list: D013232:Steel