320 ANNUAL REPORT SMITHSONIAN INSTITUTION, 194 5 



Pasteur's classical researches on fermentation were a direct outcome 

 of the misfortunes that befell France after the war of 1870. It is sur- 

 prising how often an odd fact he mentioned more or less incidentally 

 has been followed up by later investigations. Thus during the War 

 of 1914-18, German scientific men turned their attention to Pasteur's 

 observations that proteins could be synthesized by yeasts from inor- 

 ganic nitrogen, including ammonium salts. The fact that yeast, 

 including brewers' yeast, contains a high percentage of protein had 

 long been known and attempts were made to utilize the surplus 

 quantities from brewers until the production of beer was cut by 60 

 percent. In 1915, Hayduck announced that he had discovered what 

 he called "mineral yeast" as a contaminant at a pressed-yeast factory. 

 This yeast, which is non-sporing and was afterward called Torula 

 utilis, gave much better yields of protein than did other yeasts and, 

 moreover, produced little alcohol. A yeast product was put on the 

 market, but large-scale production apparently could not be carried 

 on because of lack of sugar. 



With the outbreak of the present war, the possibility of a shortage 

 of protein had to be faced, and the problem was allotted to A. C. 

 Thaysen and his colleagues at the Chemical Research Laboratory. 

 Eventually they decided that Torula (Torulopsis) utilis was most 

 likely to prove satisfactory. As the situation developed, it was realized 

 that the postwar feeding of ravaged Europe would be one of the major 

 problems, and that for some time vitamin B deficiency would be an 

 additional danger. An analysis of dried Torula utilis showed that, as 

 well as 45 to 50 percent of a protein only slightly less nutritive than 

 a good animal protein, this "food yeast" contains the whole known 

 range of water-soluble B vitamins. Further, it mixes readily with 

 water and with milk and can be used in all sorts of ways. Large-scale 

 manufacture is to be carried out in Jamaica where molasses is abund- 

 ant — 200 gm. of molasses give 50 to 60 gm. of food yeast. The Colonial 

 Development Fund has granted £150,000 for the erection of the plant 

 and it is estimated that food yeast can be marketed at 6d. per pound. 

 Many other parts of the Empire are considering erecting plants for 

 the benefit of the local population. It is understood that in Germany 

 the yeast is again being used with hydrolyzed wood as the source of 

 sugar. 



At Teddington, a strain of T. utilis was developed which will grow 

 better at tropical temperatures than would the normal form. It gives 

 a quicker yield and has less variability in size. Later, a giant strain 

 (v. major) was produced by acting on the cells with camphor: the 

 biochemical activities are identical, the variety is stable, its cells are 

 more readily separable and its generative time is considerably less. 



Another observation by Pasteur was that in ordinary yeast fermen- 

 tation a small percentage of glycerine is always produced. During 



