The vitamines of yeast and their rôle in animal nutrition

Abstract

The question whether pigeons and rats require for their well-being the same vitamine B has been discussed at length by Mitchell and Emmett a few years ago with the conclusion that vitamine B must be different from the antineuritic substance. Funk and Macallum have tested the phosphotungstate precipitate obtained from yeast and have found that while it was strongly curative for avian beriberi, it induced only moderate growth in rats. The present writers were able to show recently that by fractional adsorption with fuller's earth or norit it is possible in most cases to effect an almost quantitative separation of the B-vitamine, curative for avian beriberi from another substance, which we provisionally have called vitamine D and which acts on yeast and certain bacteria. In practice the separation is effected as follows: One liter of autolyzed yeast is shaken with 50 g. of fuller's earth; the filtrate which in the majority of cases was found inactive for avian beriberi was treated twice with the double amount of fuller's earth, the combined precipitates carrying down quantitatively the vitamine D, the last filtrate being devoid of the two above-mentioned substances.

Having succeeded in this separation (the procedure varying somewhat with different samples of autolyzed yeast) we thought it worth while to test out the fractions obtained on animals, making simultanous tests on pigeons, rats, yeast and streptococci. The experiments carried out with six rats and four pigeons in every case will be repeated and extended and the present communication is only of a preliminary character. While the pigeons were found to need only the vitamine B when fed on a vitamine-free diet, the rats exhibited a somewhat different behavior. They were fed the usual so-called synthetic diet with cod liver oil as source of vitamine A.