ABSTRACT
One of the first groups concerned with the development of a defined medium for growing bifidobacteria was that of Gyorgy and co-workers. As a prototype for their work they used the medium developed by Teply and Elvehjem for the titrimetric assay of folic acid by L. casei and L. lactis. One series of attempts to create a fully synthetic medium for bifidobacterial growth were made by Petuely and Eichler, who used the entire spectrum of amino acids to provide the nitrogen source for bacterial growth. Though bifidobacteria seem to require only a limited number of nutrients for growth, viz. biotin, pantothenate, cysteine, and possibly certain metals, these organisms nevertheless grow best in media containing such undefined biologic materials as casein hydrolysate, yeast extract, and meat extract. Bifidobacteria can degrade a number of polysaccharides via extracellular enzymes or enzymes associated with cell surfaces. A number of glycosidases useful in degrading smaller oligosaccharides are also present in cell extracts.
