1918.] AGRICULTURAL CHEMISTRY AGROTECHNY. 709 



The properties of the substance agree closely with those of levoglucosane, an 

 hydrolysis product of certain glucosids. Starch and dextrin also yield the same 

 product when distilled under reduced pressure, indicating that it is possibly the 

 primary hydrolysis product of carbohydrates in general. 



The enzyms which are concerned in the decomposition of glucose and man- 

 nitol by Bacillus coli communis, I-III, E. C. Gbey {Proc. Roy. Soc. [London], 

 Ser. B, 81 (1914), No. B 597, pp. 4^2-484, fig. 1; 90 (1918), No. B 625, pp. 75^ 

 106, figs. 5). — Part 1 of this paper deals with the action on glucose and man- 

 nitol in the presence of peptone of two artificially selected strains of B. coli 

 communis obtained by growth of normal B. coli communis on agar containing 

 sodium chloracetate. 



It was found that the selected strains produced from glucose lactic acid in 

 relatively gi-eater, and alcohol, acetic and formic acids in relatively less, propor- 

 tion than did the original strains, while from mannitol there was no diminution 

 in the production of alcohol and acetic and formic acids. It is concluded that 

 the artificially selected strains have not lost the enzyms which bring about the 

 final reaction in the production of alcohol and acetic acid, but that a diminution 

 of the reducing mechanism of the cell has resulted so that some intermediate 

 substance from which formic acid and the precursor of alcohol and acetic acid 

 are derived can not be readily decomposed. 



Part 2 reports experiments of short duration with an emulsion of the organ- 

 isms similar to those above with the exception of the omission of peptone. A 

 heater proportion of alcohol, acetic acid, and succinic acid and a smaller pro- 

 portion of lactic acid were obtained. 



The results of the experiments show that (1) succinic acid has an origin in 

 common with acetic acid and alcohol, (2) the formation of lactic acid is inde- 

 pendent of the formation of the above products, and (3) the enzyms which 

 effect the decomposition of glucose also cooperate in the decomposition of 

 mannitol. 



The author concludes that the fermentation of various carbohydrates an^ 

 allied substances by bacteria is brought about by a single set of enzyms whose 

 actions are common to all such cases of fermentation. It is possible that the 

 first step in the degradation of a particular molecular structure may require a 

 special enzym in order to produce the first intermediate substance which would 

 be the same for all analogous cases of fermentation. 



Part 3 deals with various phases in the decomposition of glucose by an emul- 

 sion of the organisms. The products resulting at different stages in the decom- 

 position of glucose by B. coli communis were analyzed with the following 

 results : During the period characterized by the rapid death of the cells there 

 was no formation of lactic acid, the sugar being transformed into alcohol and 

 formic, acetic, and succinic acids. During the period of multiplication there 

 was a transformation of glucose into a more complex substance, and in the 

 period immediately following lactic acid was produced to the extent of 70 per 

 cent of the sugar consumed. The independent existence of enzyms in the cell 

 has been shown by the fact that the amount of sugar decomposed during the 

 rapid diminution in the number of cells was as great as during the growth of the 

 cells and by the fact that the several fermentation phenomena are independent 

 of one another. 



Studies on enzym action. — XrV, Further experiments on lipolytic actions, 

 K. G. Falk (Jour. Biol. Chem., SI (1917), No. 1, pp. 97-12S). — Continuing the 

 studies previously noted (B. S. R., 34, p. Ill), a systematic investigation of the 

 factors v.'hich control the loss or destruction of the activity of the ester-hydro- 

 lyzing enzyms or lipases was undertaken. 



