Isolation of Probiotics, their Metabolites and Investigation of their Antibacterial Activities

Abstract

The present study was carried out to isolation of Probiotics Metabolites and Ant-Bacterial Activity Investigation. Probiotics were isolated from a local yogurt by using different conformational test such as: gram staining, catalase, resistance to low pH (pH 3.0&1.0), resistance to 1% bile salt (pH 6.8), 6.5% sodium chloride test, antimicrobial test by isolated strains and metabolites, and carbohydrate fermentation test. Total 15 strains were selected from commercial yogurt according to their different size of colony. 8 strains were found as Probiotics by different conformational test from yogurt, but two strains of Lactobacillus were confirmed from six strains. All strains were gram positive, catalase negative . After catalase test, all strains were selected for isolation. Then all strains were tolerated against stomach environment (pH 3.0&1.0), survived against 6.5% sodium chloride.Metabolites of strains were isolated by 60% Ammonium sulphate saturation. There were shown antimicrobial activity of selected strains and isolated metabolites against different pathogenic bacteria and also survived in acidic and neutral environment (pH 3.0 and 6.8). All strains were survived against high concentration of bile salt (1% bile salt) during 4 hour’s. 6 of them were ferment in glucose and sucrose, but 2 strains were not ferment in sucrose, only 2 strain was ferment in sorbitol . Finally I was found 6 strains of “Probiotics” and two strains of “Lactobacillus” from total strains by the help of different identical test. Morphological features of “Probiotics” were confirmed using scanning electron microscope (SEM). In conclusion, isolation of probiotics metabolites can be considered as alternative of anti-biotics, and identification of “Lactobacillus”& probiotics can be used for human healing and animals hervasting.