CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
Biological activity of Bifidobacterium longum in response to environmental pH
GARRO, M.S.; AGUIRRE, L.; SAVOY DE GIORI, G.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
Año: 2006 vol. 70 p. 612 - 612
Abstract: The influence of environmental pH on biological activity of Bifidobacterium longum CRL 849 grown in MRS-raffinose was evaluated. At pH 6.0, 5.5 and 5.0, raffinose was completely consumed by this microorganism, showing different consumption rates at each pH value (between 3.03 and 0.76 mmol l-1 h-1). At pH 4.5, the growth was lowest. The removal of raffinose was due to the alfa-galactosidase (alfa-gal) activity of this bifidobacteria, which was highest at pH 6.05.5 (1,2801,223 mU ml-1). The production of beta-glucosidase (beta-glu) showed a similar pattern to alfa-gal activity with major values. The yield of organic acids produced during raffinose consumption was also highest at pH 6.05.5. The results of this study will allow the selection of the optimum growth conditions of B. longum CRL 849, with elevated levels of alfa-gal to be used in the reduction of nondigestible alfa-oligosaccharide in soy products and beta-glu activities involved in isoflavone conversion to bioactive forms when used as starter culture.