Effect of pH on Lactobacillus fermentum growth, raffinose removal, α-galactosidase activity and fermentation products

In this study, the behaviour of Lactobacillus fermentum CRL 722 and CRL 251 were evaluated under different pH conditions (pH 6.0, 5.5, 5.0, 4.5) and without pH control. Growth was similar under all conditions assayed except at pH 4.5. These microorganisms were able to eliminate raffinose, a nondiges...

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Detalhes bibliográficos
Autores: Leblanc, Jean Guy Joseph, Garro, Marisa Selva, Savoy, Graciela
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2004
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/57294
Acesso em linha:http://hdl.handle.net/11336/57294
Access Level:acceso abierto
Palavra-chave:Lactic Acid Bacteria
Raffinose-Type Sugars
Environmental Ph
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descrição
Resumo:In this study, the behaviour of Lactobacillus fermentum CRL 722 and CRL 251 were evaluated under different pH conditions (pH 6.0, 5.5, 5.0, 4.5) and without pH control. Growth was similar under all conditions assayed except at pH 4.5. These microorganisms were able to eliminate raffinose, a nondigestible α-oligosaccharide (NDO) found in soy products, showing a consumption rate of 0.25 g l−1 h−1 (pH 6.0–5.0). The removal of raffinose was due to the high α-galactosidase (α-gal) activities of these lactic acid bacteria, which was highest at pH 5.5 (5.0 U/ml). The yield of organic acids produced during raffinose consumption was also highest at this pH. The results of this study will allow selection of the optimum growth conditions of L. fermentum with elevated levels of α-gal to be used in the reduction of NDO in soy products when used as starter cultures.