UTILIZATION OF PROTEID AND NON-PROTEID NITROGEN 19 



Tests were also conducted with anaerobes of the type of B. 

 putrificus and B. oedematis, which are characterized by their 

 strong proteolytic and putrefactive properties. No quantitative 

 bacterial determinations were attempted with these anaerobes, 

 however, and the observations were confined to a study of the 

 physical characters of the medium. No change whatever could 

 be noted in the medium; the clear liquid and the coagulated 

 albumin remaining apparently unaffected even after three to 

 four weeks of incubation. Inoculation of egg-meat medium from 

 these tubes with the aid of a platinum loop clearly demon- 

 strated the presence of putrefactive anaerobes by the rapid and 

 characteristic decomposition which took place in the standard 

 egg-meat medium. 



II. THE BEHAVIOR OF BACTERIA TOWARD PROTEOSES AND 



PEPTONES 



In text books and other bacteriological publications the assump- 

 tion is made that proteoses and peptones are readily attacked by 

 all known bacteria which are easily cultivated on artificial media. 

 So firmly has "peptone" established itself as an important in- 

 gredient of the common and standard bacteriological laboratory 

 media that its value as the source of nitrogen supply in the cell 

 metabolism of bacteria is taken as a matter of course. It is 

 true that meat extract which is practically protein-free is also 

 looked upon as practically indispensable, but not because it fur- 

 nishes food as such to the organisms. By many at least it is 

 regarded as a stimulator of cell metabohsm, due to the various 

 extractives present. 



It is one of the objects of this paper to show that proteoses and 

 peptones follow essentially the same law of resistance to direct 

 bacterial action as do the native proteins, egg albumin, serum 

 albumin and edestin. While the scope of the investigation has 

 as yet been somewhat limited, sufficient data appear to us to have 

 been acquired to warrant their publication at this time. 



It is a well-known fact that the proteoses and peptones result- 

 ing from the action of proteolytic agents hke pepsin and trypsin 

 upon native proteins, and indeed all proteoses and peptones, have 



