Quantitative evaluation of composition and biomolecular mapping of macrofungi spores by Raman spectroscopy

Raman spectroscopy is a widely used technique for detecting various chemical compounds in organic matter and creating high-resolution, label-free maps on the level of individual cells. One of the main advantages of this technique is its ability to study samples in vivo without special pretreatment. However, it is rarely used to determine the ratios between different substances or to conduct in-depth quantitative analysis of the obtained spectra. In our study, we establish ratiometric equations that enable the estimation of mass concentrations of triacylglycerols, proteins, sugars, polysaccharides, and DNA. We demonstrate that it is possible to determine the average unsaturation and chain length from the spectra of lipids and concentrations of phenylalanine, tyrosine, and tryptophan from the spectra of proteins. We apply the derived equations to the Raman spectra of fungal spores from over 70 different species of macrofungi, providing a comprehensive characterization of the lipids, proteins, and polysaccharides present in the spores. We believe that our study not only contributes valuable fundamental knowledge to the field of mycology but also lays the groundwork for the spectral quantification of any organic material. So, our approach may be applicable in areas such as food diagnostics.