Evaluation of the growth of enterobacteria in fructooligosaccharides using the principal components analysis

Luiza Siede Kuck [email protected] Universidade Federal do Rio Grande do Sul, Porto Alegre-RS Caciano Zapata Noreña [email protected] Universidade Federal do Rio Grande do Sul, Porto Alegre-RS Experimental data obtained from the literature concerning the growth rate of 35 different enterobacteria and acidification of the media using various carbohydrates as the substrates (glucose and the fructooligosaccharides Profeed P95, Raftilose P95 and Raftiline LS), were submitted to a multivariate statistical analysis of the principal components and clusters. The objective was to evaluate the degree of correlation between the substrates and the microorganisms, grouping them according to their affinities. When the growth rates of the enterobacteria were evaluated, strong correlation was observed between the substrates composed of short chain fructose oligosaccharides (Profeed P95 and Raftilose P95). The microorganisms could be separated into four groups, similarities being found between enterobacteria of the same genus and/or species. With respect to acidification of the medium, strong correlation was observed between glucose and Profeed, which have a greater percentage of glucose units in the chain. However, it was found poor correlation among microorganisms from the same genus and/or species, as well as between the enterobacteria species and fermentation of the carbohydrates. KEY-WORDS: principal component analysis; cluster analysis; enterobacteria; fructooligosaccharides.