Author(s): A. Bozza de Almeida*, CG.Poitevin, LC.Côcco2,CI.Yamamoto, PR.Dalzoto1and IC.Pimentel
In mycology, one of the challenges is to differentiate similar species. Morphology-based methods are often limited, thereby increasing the demand for new field explorations to obtain better andmore reliable results. Fourier transform infrared (FT-IR) spectroscopy is proposed as an alternative method for the classification of highly related fungi such as Aspergillusochraceusand Aspergilluswesterdijkiaeor Aspergilluscarbonariusand Aspergillusniger. However, methodologies for sample preparation are time consuming and laborious. A traditional method for sample preparation was adapted by reducing the time and maintaining the quality of analysis and a chemometric model was developed. The fungi weregrown in Sabouraud medium for 4 days, the mycelium was blended with KBr and analyzed by Fourier transform mid-infrared transmittance (FT-MIR) spectroscopy. Partial least squares regression was applied to the species comparison models and a prediction test was used to evaluate the models. The coefficient of determination for calibration and root mean square error of calibration were 0.94 and 0.23, respectively. In the external validation, only one A. westerdijkiaewas not correctly classified. Results suggest that adaptation of the methodology accelerated the process of sample preparation, maintaining reliability.