Résumé:
The present work is an attempt to isolate probiotic bacteria from breast milk and stool of babies whose main characteristic is the production of cobalamin or vitamin B12. The isolation was performed on two samples of breast milk and one stool sample. The isolation media were acidified MRS, MRS at pH 6.5. The study of phenotypic, biochemical and physiological characteristics was carried out via several tests: growth at different temperatures: 15, 37 and 45 ° C, growth at pH 5.4 and 9.6, growth in the presence of NaCl: 2.5; 4 and 6.5%, fermentative target, production of exopolysaccharides, heat resistance, bile salt resistance and the presence of an antimicrobial activity. Spectrohotometric analysis estimating cobalamin production was also undertaken with the best performing isolates.
We were able to isolate, purify and partially identify 22 probiotic isolates. All isolates have demonstrated good antimicrobial action against pathogens responsible of foodborne illness and have good resistance to bile. The amounts of vitamin B12 produced were very acceptable and estimated at the ¼ of the average daily amount of our vitamin requirements
