FTIR Spectroscopy for Identification and Intra-Species Characterization of Serpula lacrymans

Featured Application The method described in this study consists of the preparation and analysis of mycelium samples for the identification of Serpula lacrymans by FTIR. The dry rot fungus Serpula lacrymans is the most destructive fungal agent of wood building materials in Europe, Russia, North America, and Japan. The identification of this wood-deteriorating agent and the discrimination of different fungal isolates is very important for the control of buildings in general and for the preservation of cultural heritage in particular. The objective of the study was to develop a Fourier transform infrared (FTIR) method coupled with a partial least square discriminant analysis (PLS-DA) for the sample preparation and identification of S. lacrymans. Five distinct S. lacrymans strains were analysed and compared to two strains of unrelated fungal species. Different methods of mycelial growth, sample preparation, and FTIR spectral data normalisation were compared. FTIR analysis of a harvested mycelium grown on the surface of a polyether sulfone microfiltration membrane deposited on a malt extract agar medium, followed by vector normalization and PLS-DA statistical analysis, resulted in 100% correct attribution at phylum, species, and strain level, regardless of the type of standardization used. This study confirms the applicability of FTIR spectroscopy for the identification of S. lacrymans and the discrimination of different strains belonging to this species.