Waksman — 104 — Actinomycetes 



differentiating species; at best, however, this can be only a secondary 

 characteristic, 



Cellulolytic enzymes.— Although many actinomycetes are able to 

 grow on cellulose as the only source of carbon (231), the production 

 of corresponding enzymes has so far not been demonstrated. 



Lipase.— The ability of various actinomycetes to produce lipolvtic 

 enzymes has been established (260). The activity of these enzvmes 

 upon natural products is often accompanied by the formation of odor- 

 iferous substances, discussed in Chapter V. The spoilage of cacao by 

 certain species of Streptomyces (55) may possibly be due to the lipolytic 

 effect combined with odor production. 



Bacteriolytic and antolytic enzymes.— The ability of certain actino- 

 mycetes to dissolve the dead and in many cases also the living cells of 

 many bacteria has been ascribed to the action of specific lytic enzymes 

 or bacteriolysins. This phenomenon was first observed by Lieske, and 

 later studied extensively by Gratia (153, 155), who utilized this process 

 for the preparation of certain bacterial vaccines, such as typhoid vaccine. 

 The bacteriolytic substance produced by S. alhus was designated by 

 Welsch (505) as "actinomycetin." This property is widely distributed 

 among the actinomycetes, as shown in Table 19; as many as 50 per 

 cent of all cultures have been found active against heat-killed cells 

 of E. colt and against living S. aureus. 



Borodulina (43) and Nakhimovskaia (316) found that among 

 actinomycetes the lytic principle is excreted by the cells into the 

 medium, thereby inhibiting growth of bacteria found in proximity to 

 the lytic principle and, later, dissolving these bacteria. Though re- 

 sistant to heat, this substance was still considered as an enzyme. 

 Krassilnikov believed that this bacteriolytic enzyme is similar to ly- 

 sozyme of animal origin, although marked differences have been estab- 

 lished between the action of this agent and that of the lytic principle of 

 actinomycetes. Among these antibiotic preparations obtained from 

 this group of organisms, two appear to have properties which would 

 place them either with enzvme svstems or with true antibiotics. These 

 are actinomyces lysozvme and actinomycetin. Some of these lytic sys- 

 tems consist of a lipoidal bactericidal substance, a ribonucleinase, and 

 proteolytic enzymes (407). The ability of certain specific phages to 

 attack actinomvcetes has been discussed previously (p. 62). 



Production of Vitamins:— The favorable effect exerted by certain 

 actinomycetes upon the growth of various fungi was believed (171, 280) 

 to be due to their ability to svnthesize thiamin, which is produced on 

 simple synthetic media. A study has been made of 22 cultures of ac- 

 tinomycetes grown in thiamin-free media; this was followed by the in- 

 oculation of the same cultures with Phycomyces hlakesleeamis. The 

 fact was established that all the cultures produced thiamine or its inter- 

 mediate or its precursor. The production of carotinoids by certain ac- 



