August 18, 1911] 



SCIENCE 



219 



action of bacteria upon carbohydrates; while by 

 putrefaction is meant the action of bacteria upon 

 nitrogenous substances. The two phenomena, fer- 

 mentation and putrefaction, are antagonistic proc- 

 esses: the obligate putrefactive bacteria can not, 

 as a rule, grow in media in which active fermenta- 

 tion is going on, because the acids produced in- 

 hibit their development. There is a third group, 

 the -facultative organisms, which are able to adapt 

 themselves to both kinds of food. This is an 

 important new conception. Thus in the presence 

 of dextrose the diphtheria bacillus elaborates no 

 toxin, while in its absence large amounts are 

 formed. B. coli behaves similarly. Not only do 

 the products vary, but the composition of the 

 bacteria themselves may be altered. All these 

 considerations will prove of great importance in 

 practise. 



The Carlson Nitrogen Batio in the Decay of Pro- 

 tein Compounds: Jacob G. Lipman. 

 Biochemical and Toxicological Studies upon Peni- 

 oillium: C. L. Alsbeeg and O. F. Black. 



A Study of the Optical Forms of Lactic Acids 



produced by Pure Cultures of B. hulgaricus: 



James N. Cobet. 

 Nucleic Acid in Soils: Edmund C. Shoret. 

 Conditions for Tannic Acid Fermentation: Lewis 



Knudson. 



As a result of the fermentation of tannic acid 

 (gallotannic), gallic acid is formed. Van Tieghem 

 first showed that the fermentation of this sub- 

 stance may be effected by the two organisms 

 Aspergillus niger and Penicillium glaucum. Pot- 

 tevin and Fernbach simultaneously reported the 

 extraction of the enzyme tannase, the transform- 

 ing agent. Since that time several other investi- 

 gators have contributed to the subject. 



Experiments made by the writer indicate that 

 if tannic acid alone is offered as a source of 

 carbon, the gallic acid formed as a result of the 

 tannic acid transformation is utilized in the 

 metabolism of the organism — the greater the 

 growth of the fungus, the greater is the decrease 

 in tannic acid. It is likewise shown that the dura- 

 tion of growth, the presence of other nutrients 

 and aeration — factors influencing growth mass — 

 were important considerations with respect to the 

 yield of gallic acid. 



An infusion of gall nuts contains, in addition 

 to tannic acid and gallic acids, other organic com- 

 pounds as well as inorganic salts. When cultures 

 are made in which the gall nut infusion is used as 

 the nutrient solution, the tannic acid is trans- 



formed; but the gallic acid is not at first utUized. 

 The organism seems to elect the other organic 

 compounds first and then some of the gallic is 

 utilized. There is then an election of food by 

 the organism. 



If there is offered to Aspergillus niger or Peni- 

 cillium sp. in a nutrient salt solution, 10 per cent, 

 cane sugar along with 13 per cent, tannic acid, 

 then the sugar entirely protects the gallic acid 

 formed from assimilation, or use as food by the 

 fungus. A 5 per cent, concentration of sugar is 

 not sufficient to protect the gallic acid, during the 

 growth interval employed. 



Experiments were also made in which the fer- 

 mentation cultures were kept under anaerobic, and 

 also limited oxygen conditions, and the results 

 obtained were compared with those in which 

 growth was permitted under more favorable con- 

 ditions of aeration and nutrition. 



Regulatory Formation of the Enzyme Tannase: 



Lewis Knudson. 



The work of Fermi, Pfeffer, Katz, Went, Dox 

 and others has shown that to a considerable extent 

 the formation of enzymes is influenced markedly 

 by the nutrition of the organism. According to 

 Dox, the production of those enzymes that are not 

 normally developed by the organism in demon- 

 strable quantities can not be induced by any spe- 

 cial nutrition. This statement is not in accord 

 with the results obtained by Went; nor with the 

 more recent work of Harden and Norris working 

 with yeast, wherein it is shown that there may be 

 induced by special nutrition an enzyme which 

 normally did not occur in the yeast plant. The 

 work of the writer, herewith briefly reported, is 

 also in disagreement with the results of Dox. 



The two organisms, Aspergillus niger and Peni- 

 cillium sp., which normally develop on commercial 

 gall nuts when these are moistened and exposed 

 to the air, produce the enzyme tannase; and this 

 enzyme is capable of effecting the transformation 

 of tannic acid into gallic acid and glucose. 



Pottevin found that the enzyme tannase was 

 formed in Aspergillus niger when it was grown in 

 Eaulin's solution in which the sugar was replaced 

 by tannic or gallic acid. The writer has grovm 

 the organism in synthetic solutions in which the 

 carbon nutrient, cane sugar, was replaced entirely 

 or supplemented by one of several carbon com- 

 pounds. In the experiments the effect of each of 

 fourteen different carbon compounds was tested, 

 but the enzyme tannase was produced only when 

 the sugar was replaced by tannic or gallic acid. 



