The microorganisms play a major role in the processes of hydrocarbon production; they are distinguished for having different impacts due to the production of metabolites, such as enzymes, organic acids, polymers, gases, and biomass. The forty percent of all internal pipeline corrosion cases in the gas industry is microbiologically influenced corrosion (MIC) (1). Metal surfaces are rapidly colonized by planktonic-bacterium which generates in short time a mature biofilm (2). The MIC is induced by biofilms of iron and manganese reducing (5,7), sulphur-oxidizing, fermenting, slime-formers, and sulphate-reducing bacteria (2,3,4). The environmental scanning electron microscopy (ESEM), the confocal laser scanning microscopy (CLSM) and the atomic force microscopy (AFM) allow biofilm observation in real time without introducing distortion of the samples(6). The AFM has been used to obtain information about surface topography of bacteria and biofilm formation patterns (8,9). The aim of this work is to present some applications of microscopy in the study of MIC in materials of oil production installations. The physical properties of anaerobic biofilm involved in corrosion were determined by different microscopy techniques. The growth of the biofilm was measured through time by AFM Multimode-3100 Veeco Microscope with NanoscopeR IV Scanning Probe Controller (tapping methodology), ESEM (Scanning Electron Microscopy) and EDS (Energy-Dispersive X-ray Spectroscopy) with a FEI/Philips XL30 Microscope. The EDS analysis was applied to determine chemical composition of materials. A NanoScope Analysis software (2010) was used to measure the forces in order to estimate Young’s modulus (nN/nm2). The expression of the lux genes involved in the biofilm development was quantified. The results showed that surface roughness (nm) increased during biofilm development; meanwhile the tensile elasticity became greater in nN per nm2. The lux genes expression augmented substantially during the microbial growth and the development of the biofilm. The evaluation of mechanical properties of bacteria over different materials can give important information for controlling and monitoring biocorrosion in oil production industry. References: 1. Zhu X.Y., et al. 2003. Appl Environ Microbiol. 6:5354-5363; 2. Beech I.B. Gaylarde C.C. 1999. Microbiologia. 30:177-190; 3. Watkins-Borenstein S. 1994. Industrial Press USA.; 4. Videla H.A., 1996. CRC Press; 5. Mehanna M.,et al. 2009. Corros Sci 5:2596-2604; 6. Videla H.A., Herrera L.K. 2005. Int Microbiol. 8:169-180; 7. Bagge D.et al. 2001. Appl Environ Microbiol. 67(5):2319-2325; 8. Touhami A. et al. 2006. J Bacteriol. 188(2):370-377; 9. Mangold S.et al. 2008. Appl Environ Microbiol. 74(2):410-415.
The authors are grateful to Mexican Petroleum Institute and National Polytechnic Institute.