Aims: Lactose intolerance, a serious health problem for Asians, can be solved using probiotic bacteria having high lactose hydrolysis activities. We determined the distribution of β-galactosidase (β-gal), phospho-β-galactosidase (P-βgal) and phospho-β-glucosidase (P-β-glc) activities in species of lactic acid bacteria (LAB) isolated from human faeces to select strains for potential use in fermented dairy products, e.g. yogurt. Methods and Results: The sugar substrates, o-nitrophenyl-β-d- galactopyranoside 6-phosphate and o-nitrophenyl-β-d-glucopyranoside 6-phosphate, were synthesized and used to measure respectively P-β-gal and P-β-glc activities. Sixty-five toluene-treated strains were examined for three lactase enzyme activities. Lactobacillus mucosae OLL2848 showed the highest β-gal activity (107.09 U mg-1 of protein) among the Lactobacillus strains from human faeces. Lactobacillus gasseri OLL2836 and OLL 2948 showed the highest P-β-gal (46.58 U) and P-β-glc (50.19 U)activity, respectively, with no β-gal activity. Conclusions: The expression of P-β-glc induced by lactose was characteristic of Lact. gasseri. Because this LAB is a major inhabitant of the human intestine. This enzyme is a key glycosidase involved in lactose utilization. Significance and Impact of Study: This is the first report describing the distribution of three glycosidase activities used in lactose metabolism in LAB isolated from human faeces for possible use in functional foods.
- Lactic acid bacteria
- Lactobacillus gasseri
- Phospho-β- galactosidase
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology