DIFFERENTIATION OF BREWING YEAST STRAINS BY PYROLYSIS MASS-SPECTROMETRY AND FOURIER-TRANSFORM INFRARED-SPECTROSCOPY

Two rapid spectroscopic approaches for whole-organism fingerprinting-p yrolysis mass spectrometry (PyMS) and Fourier transform infrared spect roscopy (FT-IR)-were used to analyse 22 production brewery Saccharomyc es cerevisiae strains. Multivariate discriminant analysis of the spect ral data was then performed to observe relationships between the 22 is olates. Upon visual inspection of the cluster analyses, similar differ entiation of the strains was observed for both approaches. Moreover, t hese phenetic classifications were found to be very similar to those p reviously obtained using genotypic studies of the same brewing yeasts. Both spectroscopic techniques are rapid (typically 2 min for PyMS and 10 s for FT-IR) and were shown to be capable of the successful discri mination of both ale and leger yeasts. We believe that these whole-org anism fingerprinting methods could find application in brewery quality control laboratories. (C) 1998 John Wiley & Sons, Ltd.