Rust in the Abyss: Investigating the Effects of High Hydrostatic Pressure on Microbially Influenced Corrosion.

The largest proportion of the biosphere, by volume, is located in the deepest depths of the ocean and subject to high hydrostatic pressure. Many industries are increasing their exploration of the deep sea for resources such as oil, gas and minerals, as well as deploying critical infrastructure. Oil rigs, telecommunication cables and other metallic infrastructures in the deep marine environment are subject to fouling and materials degradation, but there is not a clear understanding of the effects of high hydrostatic pressure on the microbial processes inducing corrosion. In particular microbially influenced corrosion (MIC) constitutes a key, and poorly understood, aspect with important consequences for the safe and economical operation of maritime industry.

Using a novel high hydrostatic pressure (HHP) bioreactor system, coupled to a potentiostat with the ability to monitor electrochemical parameters in real-time we have started to understand the role of microoranisms on the corrosion mechanisms and how the actual corrosion rates change at pressures relevant to deep-sea infrastructures.

We also determined how both surface- and deep-water microbial communities, grown on metal surfaces, respond to changes in environmental factors with a coupled metagenomic/metatranscriptomic approach. These experiments have provided new insights into the metabolic and genetic capacities of deep sea microbial communities that utilize metals for growth.