152 



PHARMACEUTICAL BACTERIOLOGY. 



of these extraneous organisms may develop to such an extent as to modify 

 the quality of the product completely. Such fermentation diseases are a 

 source of much annoyance to manufacturers, often resulting in great finan- 

 cial loss, but this has also been the great stimulus in compelling the use of 

 pure cultures and in perfecting those methods which are known to improve 



Fig. 71.— Sak^ making. Aspergillus oryzoe, showing vegetative hyphas (a), and spore- 

 forming hyphae {b, c, d). 



the keeping qualities of the articles, whether foods or drink. Sakd in 

 particular, does not keep well, even with the greatest care in manufacture and 

 with the use of preservatives. Certain brands of beer, wine, sak^ smoking 

 tobacco, cigars, tea, etc., are known to lose their characteristic flavors within 

 short periods, due to the invasion of some "disease" producing organism. 



