THE BIOLOGICAL ACTIVITIES OF BACTERIA 53 



Lab Enzymes. There are a number of ferments produced by 

 bacteria which, although affecting proteins, can not properly be 

 classified with the proteolytic enzymes. These are the so-called 

 coagulases or lab enzymes, which have the power of producing 

 coagulation in liquid proteins. Just what chemical process 

 underlies this coagulation is not known. If Hammarsten 's 7 

 conclusions as to the hydrolytic nature of the changes produced 

 by them are true, these enzymes are brought into close relationship 

 to the proteolyzers, although a coagulation can hardly be regarded 

 as a true katabolic process. In milk where the lab-action becomes 

 evident by precipitation of casein, a strict differentiation must be 

 made between this coagulation and that brought about by acids or 

 alkalies. In the former case, casein is not only precipitated and 

 converted into paracasein, but is actually changed so that when 

 redissolved it is no longer precipitated by lab. 8 



Coagulating enzymes for milk proteins, blood, and other protein 

 solutions are produced by a large variety of bacteria. They have 

 been observed in cultures by the cholera vibrio, B. prodigosus, B. 

 pyocyaneus, and several others. 9 



The lab enzymes are easily destroyed by temperatures of 70 C. 

 and over, and are very susceptible to excessive acidity or alkalinity. 



Fat-Splitting Enzymes (Lipase). The fat-splitting powers of 

 bacteria have been less studied than some of the other bacterial 

 functions and are correspondingly more obscure. It is known, never- 

 theless, that the process is due to an enzyme and that it is probably 

 hydrolytic in nature. The following formula represents the simplest 

 method in which some of the molds and bacteria produce cleavage 

 of fats into glycerin and fatty acid: 



C 3 H 5 (C n H 2n -i 2 ) 3 + 3H 2 O = C 3 H 5 (OH 3 ) + 3C n H 2n O 2 



Glycerin Fatty acid 



Some of the bacteria endowed with the power of producing 

 lipase are the cholera spirillum, B. fluorescens liquefaciens, B. 

 prodigiosus, B. pyocyaneus, Staphylococcus pyogenes aureus, and 

 some members of the streptothrix family. The methods of in- 



7 Hamm first ctt, ' ' Textbook of Physiol. Chemistry," Translation by Mamlel. 

 s Oppenheimcr, "Dip I'Yrmoiilo u. ihre Wirknng," Leipzig, 1903. 

 9 Torini, Atti dei laborat. d. sanita, Rome, 1890. 



