MICROBIOLOGY OF FERMENTED FOODS 577 



closely resembling this organism to be responsible. Hart of the 

 University of California has, late in 1919, studied several outbreaks of 

 this character in California. He finds that the number of forage poison- 

 ing cases increases during the winter, probably because sufficient time 

 has elapsed since the preceding harvest to permit formation of toxin 

 in silage or hay. 



To date, no definite method of preventing the growth of this organ- 

 ism in silage has been developed, although its growth is undoubtedly 

 influenced by the composition of the silage and the character of the 

 fermentations taking place in the product. It would appear logical 

 to induce vigorous lactic fermentation in the silage in order to check 

 the development of B. botulinus. 



Hart of California found the two groups, namely, A and B strains, 

 of the organism in forage poisoning cases and confirmed the work of 

 others that the antitoxin from an A strain does not protect against 

 the toxin of a B strain and vice versa. He has not had any notable 

 success in preventing the death of animals already showing symptoms 

 of botulism by the use of antitoxin but has obtained protection where 

 the antitoxin is administered with the toxin or very shortly afterward. 

 He has succeeded in immunizing horses to very heavy doses of the 

 toxin and has thereby obtained the antitoxin in quantity. 



The problems presented are extremely serious and important and 

 well worthy the attention of all investigators in states which use the 

 silo extensively. B. botulinus has of late intruded itself upon our atten- 

 tion in many ways and its control offers one of the most important 

 problems confronting the bacteriologists of this country. 



MALT SYRUPS* 



Several types of malt syrup are produced commercially in the 

 United States. The most common form is that used by bakeries in 

 bread making. In preparing this syrup kiln dried malt is ground, 

 mixed with water and mashed, first at a temperature of 50 to 52 to 

 favor lactic fermentation, and later at 60 or higher to convert the re- 

 maining starch into maltose and dextrin. The resulting liquid is 

 strained or filtered and is concentrated in vacuo to about 78 Balling. 

 One of the most important constituents of the syrup is the i to 3 per 

 cent, of lactic acid content. This is usually formed by selected strains 



* Prepared by W. V. Cruess. 

 37 



