2i6 SECTIONAL ADDRESSES 



vitamin. Most moulds are able to synthesise fats and sterols. It has 

 been found that many moulds give better results than do yeasts, among 

 the best being Aspergillus Sydowi and Paecilomyces Varioti. In America 

 ergosterol is being produced on a commercial scale by the growth of 

 moulds ; in addition to a greater yield than from yeasts, the commercially 

 valuable takadiastase is a by-product. 



Many investigators have studied the production of fats and proteins 

 by moulds. G. E. Ward, L. B. Lockwood, O. E. May and H. T. Herrick 

 recently investigated fat production in sixty-one Aspergilli and Penicillia 

 and found that in ten of them more than 15 per cent, ether-soluble 

 material was formed. One species, Penicillium javanicum from rotten 

 tea-roots in Java, gave as much as 41*5 per cent, fat in 40 per cent, 

 glucose. 



Since Delbriick's experiments in 1910 it has been known that ordinary 

 yeast can be utilised for food : for animals it is merely dried but for human 

 food it is treated so that it resembles meat extract in appearance, flavour 

 and composition. In Germany a portion of the excess yeast from brew- 

 eries is used for making yeast extracts traded under various names. 



Marmite (known in America as Vegex) is an extract prepared by auto- 

 lysis from fresh brewers' yeast ; the ferments are killed during the manu- 

 facturing process. Because of its vitamin B complex Marmite was used 

 as a ration in Mesopotamia and other war areas where beri-beri was preva- 

 lent. 



At the outbreak of the War the German yeast-drying factories were 

 fully mobilised and produced 20,000 tons of dried yeast annually for food. 

 When the government reduced the production of beer to 60 per cent, of 

 its pre-war amount Torula utilis, ' mineral yeast,' was used in considerable 

 quantity to supplement the bread ration. This non-sporing yeast is a 

 poor fermenter and was cultivated in very dilute molasses with super- 

 phosphate, magnesium sulphate and ammonium sulphate with free 

 aeration. No alcohol was formed but 100 grams of molasses produced 

 130 grams of yeast in eight hours. 



The Russians also turned their attention to utilising yeast to help to 

 supplement food-stuffs of which the War had brought about an acute 

 shortage. A commission was appointed in 191 7, G. A. Nadson and A. G. 

 Konotine being members. Attention had been called by P. Lindner to the 

 possibility of cultivating certain yeasts for the production of fat. The 

 Russians used Endomyces vernalis, ' fat yeast,' which was originally found 

 in slime fluxes of birch and hornbeam. Like Torula utilis, Endomyces 

 vernalis produces no alcohol. It will grow on different sugars and first 

 develops as long branched hyphse.rich in proteins, but containing scarcely 

 any fat. Later the hypha? break up into oidia and the fat content 

 increases, reaching fifteen to twenty per cent, of the dry weight in 

 ten to fifteen days. The fat is a yellowish liquid resembling olive oil. 

 Its chief constituent is triolein but free fatty acids are also present. 



Chaston Chapman in 1926 found a species of Oidium blocking up sewers, 

 which in two days formed a thick film on nutrient solution ; this film 

 contained fifty per cent, crude protein and ten per cent, fat and had the 

 odour and flavour of cream cheese. The possibilities attaching to such 



