ISOLATION AND ENUMERATION OF BIFIDOBACTERIA IN FERMENTED MILK-PRODUCTS - A REVIEW

Fermented foods containing selected strains of bifidobacteria are clai med to contain several therapeutic benefits. Several media could be us ed for selective enumeration of bifidobacteria, however, further resea rch is needed to develop a medium to isolate whole spectrum pf species within the genus Bifidobacterium from products containing yogurt bact eria, L. acidophilus, and bifidobacteria. If a product contains bifido bacteria only, glucose-blood liver (BL) agar, reinforced clostridial a gar (RCA) or brain-heart infusion (BHI) agar could be used for enumera tion using anaerobic incubation. If the product contains bifidobacteri a and other lactic acid bacteria, neomycin sulphate, nalidixic acid, l ithium chloride, and paromomycin sulphate (NNLP) agar may be the mediu m of choice. ''Bifidus-blood'' agar could also be used for selective e numeration of bifidobacteria. However, counterchecking the efficacy of the medium with pure cultures of Bifidobacterium spp. before adopting the medium is suggested.