**3.4 Final remarks**

From the results discussed and described above, it can be concluded that Raman spectra allow obtaining chemical information related with bacteria/metal interactions, and also with metal ion concentrations. PCA allowed an efficient elucidation of the information obtained from the spectra. Furthermore, the one-dimensional loadings analysis allowed identifying the influent spectral regions, as well as the molecular structures involved in the objects/samples distribution in the scores plots.
