DECOMPOSITION OF ORGANIC COMPOUND 233 



capable of bringing about decomposition of such native 

 proteins as albumin or fibrin under anaerobic conditions 

 without the presence of any carbohydrates. The bacteria 

 may usually be seen readily in stained mounts taken from 

 putrefying material. 



The Aerobic, Proteolytic Bacteria. — Various bacteria 

 belonging to the genera Bacillus, Proteus and Pseudomonas, 

 together with certain molds are able to bring about decom- 

 position of proteins under aerobic conditions. The organ- 

 isms belonging to the genus Bacillus have usually been 

 regarded as among the most important of the bacteria in the 

 soil in bringing about decomposition of nitrogenous com- 

 pounds. The recent work of Conn and others seems to 

 throw some doubt upon their importance in the soil, inas- 

 much as apparently they are usually present in the form of 

 spores. "When grown in the laboratory, however, most 

 species of the genus Bacillus are capable of digesting gela- 

 tin and frequently proteins such as albumin or egg white 

 are digested as well. Typical of this group is the Bacillus 

 mycoides. This organism is a comparatively large rod, 

 usually occurring in long chains and, when grown upon 

 culture media, producing rootlike extensions from the sides 

 of the colonies. The spores are formed readily, are 

 equatorial in position and do not cause an enlargement of 

 the cell. It grows readily upon ordinary culture media. 

 Milk, blood serum and gelatin are all liquefied. The organ- 

 ism is particularly active in the development of am- 

 monia. 



Members of the genus Pseudomonas, such as Pseudomonas 

 fluorescens, and members of the genus Proteus, such as 

 Proteus vulgaris, are probably also important in bringing 

 about ammonifieation. 



Certain molds, particularly members of the genus Peni- 

 cillium, are active in producing hydrolysis in certain pro- 

 teins, particularly the proteins of milk. It will be noted 



