The use of optical spectroscopy as abiomarker probe for fungi identification

Abstract

Spectroscopic techniques includinginfrared,Raman (FT-Raman) and ultraviolet spectroscopy (UV-Vis)spectroscopy were used to identify and differentiate three fungi within the same Aspergillus genus (A. fumigatus, A. terreusand A. nidulans) according to the biochemical composition of their pigments.The three spectroscopic techniques are complementary and were found to identify different biomarkers in the fungal pigments. UV-Vis absorption bandsindicate that the fungi contain numerous pigments, which may be usedfor differentstrategies for their survival.The results showed that the spectroscopic techniques are straightforward and rapid for the identificationof micro-organismsaccording to their pigment structures. The results demonstrate that:(a) integrationof different spectroscopic techniques gives a complete rapid, accurate and straightforward view for fungal characterization according to their pigment structure;(b) the pigments from the A. fumigatus and A.terreusspecies are chemically similar but different from those in the A. nidulansspecies; and (c) diagnostic groups of corroborative peaks from the spectra can be used to identify certain compoundssuch asthe melanin compound in FT-IR spectra,which is confirmed bythe presence of porphyrin compoundsshown in the UV spectra.