Abstract
In discussing the nutritional requirements of the microörganisms, we cannot overlook the important rôle that the vitamines play. The identity of the vitamine that influences the growth of the lower organisms is still an open question. The bulk of evidence, however, points strongly to the conclusion that this substance is distinct from vitamine B, although it is closely related to it; and our results lead us to draw the same conclusion.
Preliminary experiments with beef-heart infusions, peptone, and autolyzed yeast solutions, have shown us that these media contain substances which have a comparable growth-stimulating action on hemolytic streptococci and yeast cells. Thus a beef-heart infusion gives a profuse growth when inoculated with streptococci, whereas this medium, when decolorized by boiling with 2 per cent. of its weight of norit charcoal, loses its growth-stimulating activity, even on addition of a glucose-salt solution. This confirms some of the results obtained by Mueller. When 1 per cent. peptone or autolyzed yeast solutions are added to the decolorized infusion, the medium again becomes favorable for the growth of streptococci. Analogous results were obtained with these substances on the growth of yeast cells.
As it was more desirable to separate these activating substances from the bulk of impurities with which they are associated in their natural media, we subjected beef-heart infusions and autolyzed yeast solutions to fractional adsorption by means of fuller's earth and norit according to the method of Funk and Dubin. These authors have shown that at least two different substances can be separated from autolyzed yeast by means of fractional adsorption with fuller's earth. By this method it is now possible to separate the vitamine active for yeast growth, which has been provisionally called “vitamine D,” from that of the anti-beriberi or B vitamine.
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