title: Mass spectrometric metabolomic imaging of biofilms on corroding steel surfaces using laser ablation and solvent capture by aspiration.
abstract: Ambient laser ablation and solvent capture by aspiration (LASCA) mass spectrometric imaging was combined with metabolomics high-performance liquid chromatography (HPLC) mass spectrometry analysis and light profilometry to investigate the correlation between chemical composition of marine bacterial biofilms on surfaces of 1018 carbon steel and corrosion damage of steel underneath the biofilms. Pure cultures of Marinobacter sp. or a wild population of bacteria present in coastal seawater served as sources of biofilms. Profilometry data of biofilm-free surfaces demonstrated heterogeneous distributions of corrosion damage. LASCA data were correlated with areas on the coupons varying in the level of corrosion attack, to reveal differences in chemical composition within biofilm regions associated with corroding and corrosion-free zones. Putative identification of selected compounds was carried out based on HPLC results and subsequent database searches. This is the first report of successful ambient chemical and metabolomic imaging of marine biofilms on corroding metallic materials. The metabolic analysis of such biofilms is challenging due to the presence in the biofilm of large amounts of corrosion products. However, by using the LASCA imaging interface, images of more than 1000 ions (potential metabolites) are generated, revealing striking heterogeneities within the biofilm. In the two model systems studied here, it is found that some of the patterns observed in selected ion images closely correlate with the occurrence and extent of corrosion in the carbon steel substrate as revealed by profilometry, while others do not. This approach toward the study of microbially influenced corrosion (MIC) holds great promise for approaching a fundamental understanding of the mechanisms involved in MIC.
authors.affiliation: Department of Microbiology and Plant Biology University of Oklahoma, Norman, Oklahoma 73019.
authors.forename: Jonathan I
authors.initials: JI
authors.lastname: Brauer
authors.affiliation: Department of Microbiology and Plant Biology University of Oklahoma, Norman, Oklahoma 73019.
authors.forename: Zakari
authors.initials: Z
authors.lastname: Makama
authors.affiliation: Department of Microbiology and Plant Biology University of Oklahoma, Norman, Oklahoma 73019.
authors.forename: Vincent
authors.initials: V
authors.lastname: Bonifay
authors.affiliation: Department of Microbiology and Plant Biology University of Oklahoma, Norman, Oklahoma 73019.
authors.forename: Egemen
authors.initials: E
authors.lastname: Aydin
authors.affiliation: Department of Microbiology and Plant Biology University of Oklahoma, Norman, Oklahoma 73019.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Kaufman
authors.affiliation: Department of Microbiology and Plant Biology University of Oklahoma, Norman, Oklahoma 73019.
authors.forename: Iwona B
authors.initials: IB
authors.lastname: Beech
authors.affiliation: Department of Microbiology and Plant Biology University of Oklahoma, Norman, Oklahoma 73019.
authors.forename: Jan
authors.initials: J
authors.lastname: Sunner
mesh_terms: D001419:Bacteria / Q000737:chemistry* / Q000254:growth & development* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D002851:Chromatography, High Pressure Liquid; D003343:Corrosion; D004783:Environmental Microbiology; D013058:Mass Spectrometry; D055442:Metabolome; D061848:Optical Imaging; D013232:Steel
chemical_list: D013232:Steel