Probiotics Bacteria from Egyptian Infants cause Cholesterol Removal in Media and Survive in Yoghurt

Abstract

One of the most significant groups of probiotic organisms are the lactic acid bacteria, commonly used in fermented dairy products. In this study, cultures were isolated from two infants. After screening for the classic properties of pro-biotic organisms, four promising isolates were identified as two strains of Lactobacillus acidophilus (P106, P110), strain of Lactobacillus plantarum (P164) and Lactobacillus pentosus (P191) which were tested for capability to remove cholesterol and to deconjugate sodium taurocholate from the culture medium. Results showed that a considerable variation existed among cultures in their growth viability in the presence of bile salt, deconjugation of sodium tauro-cholate and assimilation of cholesterol from the medium. All tested strains removed less cholesterol from the broth (ranged from 4.02% -24.32%) compared to those grown in broth supplemented with 0.2% bile salts (from 29.02 to 45.3). Lactobacillus acidophilus P106 appeared to be more active in bile salt hydrolase compared to the other strains, and therefore, is regarded as a suitable candidate probiotic and adjunct culture. These strains were employed to make yoghurt and, in order to achieve a short production time; a two-stage fermentation procedure was used with Strepto-coccus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus providing the rapid acidification. Storage trials at 4˚C showed that the viability of the probiotic cultures was retained over 15 days.