and textile cleaning; in short, any pixjcess where the removal of minor 

 amounts of proteins, fats, or carbohydrates present as impurities in a 

 product or material is desired. 



Present sources of raw material 



It is readily seen that the above applications of enzymes would 

 necessitate volume production and thus many sources have been investigated 

 and utilized. Probably the largest single enzyme source is the mammal 

 digestive tract, particularly the pig pancreas and gastric mucosa. 

 Certain vegetable tissues, such as the Carica papaya, pineapple and 

 Mexicain, yield extracts high in proteolytic enzymes. Enzymes are also 

 successfully produced from certain molds and bacteria grown on appropriate 

 media. 



Methods of manufacture 



The easiest method for producing enzymes commercially is an acid 

 aqueous extraction of active tissues and precipitation of the enzymic 

 protein by adding alcohol or acetone. In the case of vegetable enzymes 

 such as papain from papaya, the process is simplified to the collection 

 of latex and subsequent drying. However, the preparation of a single 

 purified enzyme requires a considerable amount of repetitious reprecipi- 

 tation and recrystallization since the aqueous solution extracts a mix- 

 ture of enzymes which must then be segregated by selective precipitation. 

 It must be remembered that enzymes are specific; that is, they catalyze 

 the reaction of one and only one substance. Thus to achieve a definite 

 reaction and product, the appropriate enzyme must be used in pure form; 

 otherwise undesirable side reactions and non-uniform products would result. 



Economics of manufacture 



The numerous sources used for enzjTne preparation are a result of an 

 increasing demand conflicting with a limited supply. Thus, originally 

 enzymes were extracted mainly from mammal organs, but as competing uses 

 of these organs developed, such as the preparation of insulin from mammal 

 pancreas, it became necessary to utilize papaya, molds, and bacteria to 

 provide an adequate and yet economical supply of enzymes. In view of the 

 increasing use of enzymes in industry and as new applications are found, 

 it would appear that the market could readily absorb, and, in fact, 

 will eventually require, an increased production of purified enzymes. 



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