Some Characteristics of Practical Relevance of the B-Galactosidase from Potential Probiotic Strains of Propionibacterium acidipropionici.

ZÁRATE G, PEREZ CHAIA A. AND OLIVER G.

ANAEROBE

ELSEVIER SCI LTD

Lugar: Orlando, Florida,U.S.A.; Año: 2003 vol. 8 p. 259 - 267

1075-9964

TITULO: Some Characteristics of Practical Relevance of the b-Galactosidase from Potential Probiotic Strains of Propionibacterium acidipropionici. AUTORES: Zárate G*, Perez Chaia A. and Oliver G. RESUMEN In the present study, factors influencing the synthesis and activity of b-galactosidase of two strains of Propionibacterium acidipropionici with some probiotic properties are described for the first time. The enzyme 6-phospho-b-D-galactosidase of the PEP-PTS system was not detected, suggesting that Propionibacterium acidipropionici metabolize lactose only by using b-galactosidase. The highest enzymatic activities were obtained from cultures developed in a basal broth medium containing 1.0 % sodium lactate or 0.25 % lactose. Maximum b-galactosidase activity from cell-free extracts of the strains was obtained at pH 7.0 and 50 ºC, but a high activity was even detected at 37°C. The enzyme was competitively inhibited by lactose and activated by glucose and sodium lactate. The remaining activities after heating cell-free extracts up to 20 min at 60°C were 70 and 25 % of untreated control activities for Propionibacterium acidipropionici Q4 and CRL 1198 respectively.  Cations like Mg2+, Mn2+, Li+, Na+, and K+ acted as stimulators of the b-galactosidase activity whereas Ca2+, Co2+, Ni2+, Hg2+ and Cu2+ showed inhibitory effect in different extent. These results suggest that the environmental conditions commonly present in the human’s intestine may be adequate for the synthesis and activity of b-galactosidase from these strains of Propionibacterium. The enzyme resist the cooking temperature of Swiss-type cheeses in different extent depending on the strain and most of the cations present in milk stimulate the enzymatic activity. Our results suggest that a cheese would be an appropriate vehicle for delivery of b-galactosidase from propionibacteria to the host and efforts to develop a Swiss-type probiotic cheese for lactose intolerant persons should be done.