Application of bioinformatics to spectral analysis: soil organic carbon structure distinguished by X-ray photoelectron spectroscopy.

Spectroscopy, a powerful tool for analyzing material structure and composition, often encounters difficulties when investigating complex systems, such as soil and water. Here, it is hypothesized that bioinformatic methods based on the definition of the operational taxonomic unit can be applied to spectral analysis and to improve the resolving power of spectroscopic approaches. To test this hypothesis, we investigated SOC structure in response to three fertilization regimes using X-ray photoelectron spectroscopy (XPS). The operational taxonomic unit in spectroscopy (OTUsp) was defined and then the Manhattan plots were performed. Our approach turned out to be successful in determining the discrimination of SOC structure, while the traditional peak fitting method of XPS spectra failed. The results were then validated by chemical extraction analysis. Spectral analysis based on OTUsp can supplement traditional spectral interpretation and enhance its usability for studying complex systems. Graphical abstract.