Microbiology induced corrosion in AA6061 alloy by the genera Pseudomonas: PAO1-GFP strain as a model for biocorrosion testing

A.F. FORTE GIACOBONE; MAGDALENA PEZZONI; SEBASTIÁN A. RODRÍGUEZ; BURKART, A. L.; CORTÓN, EDUARDO; RAMON A PIZARRO; CRISTINA C COSTA

Buenos Aires

Congreso; Proceedings at the MRS 2011 XXXV International Symposium "Scientific Basis for Nuclear Waste Management?; 2011

Comision de Energia Atomica

Aluminum alloy AA 6061 is used in the fabrication of nuclear fuel elements for research reactors. Spent fuel elements of AA 6061 are stored in demineralized water basins. The ultrapure and radioactive character of the water does not prevent microbial growth. Previously, 20 different biofilm-forming bacteria have been isolated from a nuclear waste pool in Argentina, including several strains belonging to the genus Pseudomonas. To have microbiological induced corrosion (MIC) it is necessary the existence of a biofilm. One of the mayor problems of biofilm research is the difficult to follow biofilm development in vivo. The use of genetically modified microorganisms capable to produce the green fluorescent protein (GFP) has been of way to overcome this obstacle since biofilms can be easily followed by epifluorescence microscopy, a non invasive method. The objective of this work was to compare the biofilm formation and corrosion on AA6061 in high diluted media by a strain isolated from the nuclear waste pool with regard to the prototype strain Pseudomonas aeruginosa PAO1 and its derivative carrying the reporter gene GFP, to employ the last strain as model in MIC. Biofilm and corrosion evaluation were performed both by epifluorescence microscopy and SEM EDX. Our results show that PAO1-GFP strain can develop biofilm and induce MIC on AA6061 in high diluted media. This result implies that PAO1-GFP could be used as a model to study biofouling and MIC of AA6061 in nuclear waste pools.