THE NUTRITIONAL REQUIREMENTS OF LACTOBACILLUS BIFIDUS AND LACTOBACILLUS LEICHMANNII

Publisher Website
Google Scholar
Abstract
The specific nutritional requirements were detd. in media containing vit. B12 as compared with media containing desoxyribonucleic acid (DNA). In the presence of DNA, neither organism requires purine bases. If thymidine is substituted for DNA, L. bifidus is unable to utilize xanthine which supports growth in the presence of vitamin B12. Ferrous or ferric ions are essential for the growth of L. bifidus when the organism is grown in the presence of vitamin B12 but not when it is grown in the presence of DNA. L. leichmannii requires a purine for growth in a medium containing thymidine but grows to a limited extent in the absence of a purine in media containing vit. B12 provided a pyrimidine is supplied.