An investigation of biooxidation ability of Acidithiobacillus ferrooxidans using NMR relaxation measurement

► NMR relaxation measurements (T2) can provide iron oxidation activity of bacterial cells. ► The iron oxidation ability of Acidithiobacillus ferrooxidans was investigated. ► T2 shortening was found with increasing time as the bacteria oxidize Fe2+ to Fe3+ ions. ► Bacteria concentration increased 80 times and high iron oxidation ability was found in 9K−. ► The measurement has the advantage of in situ, non-intrusive, and fast.