NIR techniques in yeast identification

Abstract

The suitability of near infrared reflectance spectroscopy (NIR) for the rapid identification of different yeasts was tested. Yeasts were grown in batch culture and samples were taken from the exponential and stationary growth stages; later samples were divided into aliquots, one of which was heat-shocked. The four yeasts tested were morphologically different. Optimal growth temperatures were all in the range of 30-35°C and at 30°C growth rates of mixed cultures did not differ significantly from those of monocultures. NIR spectra of the strains investigated were significantly different. The growth stage or heat-shock treatment had significant effects on the spectrum. Mixtures of two pure cultures (0, 10, 20 . . . 90% "infection") had NIR spectra which were intermediate to those of the pure culture and even 10% contamination caused a significant difference. © Springer-Verlag 1997.