PREBIOTIC EFFECTIVENESS OF GALACTOOLIGOSACCHARIDES AND P-GLUCAN IN STIMULATION OF GROWTH OF LACTOBACILLUS ACIDOPHILUS NCDC 13 IN VITRO

摘要

Prebiotic effectiveness ofgalactooligosaccharides (GOS) and barley (5-glucan preparation to stimulate the proliferation of a potentialprobiotic, Lactobacillus acidophilus NCDC 13 was studied in vitro by measurement of decline in pH, increase in OD_600 of medium and viable counts of the probiotic bacterium. Both preparations were evaluated in the concentration range of 1-5% (w/v) added to carbohydrate free basal medium. GOS supplementation at 2% (w/v) was found to be optimum for growth of probiotic up to 9 log cfulml in 12 h. Higher GOS supplementation did not result in improvement of viable counts. fi-Glucan addition at a level of 3% (w/v) resulted in increase in viable counts by -2 log cycle in 12 h. High viable counts (around 10 log cfulml) were obtained by adding fi-glucan at concentrations of 4-5% (w/v), however, the medium turned highly viscous. Barley fi-glucan seemed to be a slightly better substrate as compared to the GOS preparation for proliferation of Lactobacillus acidophilus NCDC 13. Both the prebiotic carbohydrates may act as suitable substrates in maintaining the sufficient number of viable counts of the probiotic in synbiotic preparation.