Inhibition of Bacillus cereus in milk fermented with kefir grains

• Autores: Kakisu, Emiliano J.; Abraham, Analía Graciela; Pérez, Pablo Fernando; De Antoni, Graciela Liliana
• Año de publicación: 2007
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Química; Kefir-fermented milk; Bacillus cereus
• Institución: Universidad Nacional de La Plata

The effects of kefir-fermented milk were tested against a toxigenic strain of Bacillus cereus. The incubation of milk with B. cereus spores plus 5% kefir grains prevented spore germination and growth of vegetative forms. In contrast, when 1% kefir grains was used, no effects were observed. The presence of metabolically active kefir grains diminished titers of nonhemolytic enterotoxin A, as assessed by enzyme-linked immunosorbent assay. During fermentation, kefir microorganisms produce extra-cellular metabolites such as organic acids, which could play a role in the inhibition of spore germination and growth of B. cereus, although the effect of other factors cannot be ruled out. Results of the present study show that kefir-fermented milk is able to antagonize key mechanisms involved in the growth of B. cereus as well as interfere with the biological activity of this microorganism.
Centro de Investigación y Desarrollo en Criotecnología de Alimentos
Facultad de Ciencias Exactas