LONG-CHAIN FATTY-ACID COMPOSITION AS A CRITERION FOR YEAST DISTINCTION IN THE BREWING INDUSTRY

The diversity of yeasts isolated from brewing plants and its role on b eer quality makes yeast distinction a major concern in industrial micr obiological control. Several approaches have been tried to develop rap id and simple methods to perform such tasks. Among these, stands the u tilization of long-chain fatty acid composition of total yeast biomass . in this paper results are reported showing the potential of this tec hnique to characterize yeast flora isolated from industrial plants. Fa tty acid profiles of brewing species are clearly differentiated from t hose of non-Saccharomyces strains using statistical data treatment by principal component analysis (PCA). Distinction between brewing and wi ld strains of Saccharomyces spp. was not apparent. In comparison, fatt y acid profiling showed higher discriminating ability than growth on l ysine medium for non-Saccharomyces strains. For distinction of S. cere visiae var. diastaticus from other Saccharomyces strains, growth on st arch medium showed to be necessary.