ISOLATION OF DAIRY BACTERIA AND ASSESSMENT OF THEIR β-GALACTOSIDASE ACTIVITY AS A PROBIOTIC AND TECHNOLOGICAL PROPERTY

SAEZ, GD; CORDOBA-VIRLA, MS; PALACIOS, JM; GULTEMIRIAN, ML; ZÁRATE, G

BIOCELL

INST HISTOL EMBRIOL-CONICET

Lugar: Mendoza; Año: 2012

0327-9545

In recent years, probiotics have attracted the interest of both industry and consumers. An important probiotic property is the ability of microbial b-galactosidase to contribute to the intestinal metabolism of lactose by hydrolyzing  this disaccharide inside the food and within the intestine. In addition to hydrolase activity, b-gal leads to the formation of prebiotic galactooligosaccharides by transglycosylation reactions. In this work, we isolated LAB and assessed their b-gal activity in order to select the strains with the ability to hydrolyse lactose and to produce GOS. Lactobacilli from artisanal cheeses were isolated in selective culture media and identified by biochemical tests. b-gal and the products formed from lactose were determined by a colorimetric method and HPLC. Thirty five NSLAB belonging to facultative heterfermentative (60%); obligate heterofermentative (31,5%) and obligate homofermentative (8,5%) groups were isolated. b-gal activities ranged from 120 to 1450 nmols ONP min-1 mL-1. When exposed to gastrointestinal conditions some strains lost viability and b-gal in a significant manner. One Lactobacillus plantarum and L..paracasei strains were selected for further studies due to their high b-gal, gastrointestinal tolerance and  hydrolase/transferase activities