Microorganisms form biofilms on various surfaces in different environments and cause diverse problems such as biofouling and biocorrosion. Biofilm formation includes at least three steps: initial adhesion, colonisation, and development. In this study, we enriched bacterial populations capable of adhering to a metallic iron surface. The community structure of the enriched populations differed from the structures of those without enrichment. From the enriched populations, we isolated six strains capable of adhering to the surface of metallic iron. A Marinobacter hydrocarbonoclasticus strain M1 showed the highest adhesion rate of approximately 4×10 6 cells cm −2 min −1 . Atomic force microscopy showed that a high density monolayer of cells was formed within a few minutes of adherence of single cells of this strain to the surface of metallic iron.