Usher, K. M.Kaksonen, A. H.Cole, I.Marney, D.2026-07-032026-07-030964-8305ORCID:/0000-0001-6582-1457/work/219176323https://hdl.handle.net/1885/733812506External corrosion of buried carbon steel pipes is a problem of global proportions, affecting a wide range of industries and services. Many factors affect corrosion rates. Biofilms may secrete enzymes and compounds that attack metal, alter local acidity and create differential aeration and galvanic cells. An important consideration is that biofilm metabolisms and enzymatic reactions are constantly in flux, altering the impact of microorganisms on corrosion rates, and thermodynamic equilibrium is not reached. Recent research demonstrates that some anaerobic microorganisms catalyse the oxidation of metallic iron and directly consume the electrons, with serious consequences for corrosion. This review examines relationships between soil characteristics, microbiology and corrosion processes, focussing on the impacts of microorganisms on external corrosion of buried carbon steel pipes. Techniques for improving the understanding of microbially influenced corrosion are considered and critiqued, with the aim of assisting those who work in the area of corrosion mitigation.This work was funded by CSIRO through Office of Chief Executive (OCE) Post Doctoral Fellowship scheme and Water for a Healthy Country Flagship. These bodies did not have a role in the design or preparation of this paper. The authors acknowledge Dr Peta Clode and the facilities, scientific and technical assistance of the National Imaging Facility at the Centre for Microscopy, Characterisation & Analysis, The University of Western Australia, a facility funded by the University, State and Commonwealth Governments. The authors also thank the anonymous reviewers for their contributions.23enBuried steelCarbon steelExternal corrosion of pipesMicrobially influenced corrosion201410.1016/j.ibiod.2014.05.00784902107299