226 PHYSIOLOGY [Bot. Absts., Vol. IV, 



1504. Bodansky, M. A note on the determination of catalase in blood. Jour. Biol. Chem. 

 40: 127-130. 1919. — There seems to be no satisfactory absolute method for the determination 

 of catalase. Temperature and P H values are important factors, and there is no well denned 

 Ph value for maximum action. — G. B. Rigg. 



1505. Edie, Edward Stafford. The effect of alcohol on the digestion of fibrin and casein- 

 ogen by trypsin. Biochem. Jour. 13: 219-225. 1919. — The action of trypsin on fibrin is 

 inhibited when alcohol is present to the extent of 3 per cent while the digestion of caseinogen 

 by the same enzyme is not effected until the alcohol concentration reaches 10 per cent. The 

 author concludes the harmful action is not due to the destruction of trypsin by alcohol since 

 dilute alcohol seems to aid digestion. The suggestion is made that if trypsin is a single 

 eDzyme, the digestion of fibrin and caseinogen is probably carried out by side chains, those 

 digesting fibrins being more readily effected by alcohol than others. — A. R. Davis. 



1506. Euler, Hans V., and Ragnar Blix. Verstarkung der Katalasewirkung in Hefe- 

 zellen. [Accelerating catalase action in yeast cells.] Zeitschr. Physiol. Chem. 105: 83-114. 

 1919. — The authors have determined the effect of various conditions and reagents upon the 

 catalase activity of yeast cells. Where possible they used the potassium permanganate titra- 

 tion method for determining catalase activity. In cases where additions of thymol, glucose, 

 etc., rendered the permanganate method inaccurate, the volumetric method was used. They 

 used mainly their cultures of distillery top yeast S. B. II. Some experiments were run with 

 brewery bottom yeast. They agree with Phragmen's findings that yeast splits dilute solu- 

 tions of hydrogen peroxide without secreting a soluble enzyme into the bathing fluid. The 

 reaction is one of the first order. The reaction constant increases in proportion to the 

 amount of yeast. Small amounts of protosplasmic poisons (toluol or chloroform) raise the 

 catalase activity of these cells six-fold. When cells were dried in the air or otherwise without 

 injuring them the catalase activity rose ten to fifteen fold. When emulsions of the yeast were 

 heated | to 2 hours at 55° to 63°C. the catalase activity rose twenty to thirty fold. The ac- 

 tivation by heating is greatly influenced by reagents in the emulsion at the time of heating. 

 Similar activation of catalase has been demonstrated in a number of other microorganisms. 

 The catalase activity of yeast can be raised by previous treatment with sugar solutions. This 

 increased catalase activity is not due to increased permeability of the cells to catalase, but 

 is an activation within the living cells. The reaction constant is not a measure for the cata- 

 lase content of the cells. — William Crocker. 



1507. Euler, H., and O. Svanberg. Enzymatische Studien iiber Zuckerspaltungen. 

 [Enzymatic studies on sugar fermentation.] Zeitschr. Physiol. Chem. 105: 187-239. 1919. — 

 Euler and Svanberg made a study of alcoholic fermentation in an alkaline medium in which 

 P H — 8. Top yeast and Torula gave about equal weights of carbon dioxide and alcohol, each 

 equal to 30 to 33 per cent of the weight of the sugar fermented. Glucose, fructose, and invert 

 sugar were fermented with about equal speed, mannose about 30 per cent as fast, and galactose 

 very slowly. Invertase is active in this medium and maltase inactive. The following are 

 the maximum alkalinities in which cell division occurs in the various yeasts. Frohberg 

 Unterhefe H, P H = 7.7-8.0; Brennerei-Oberhefe S. B. II, P H = 7.3-8.4; Saccharomyces ellip- 

 soideus, P H = 7.9; Pseudosaccharomyces apiculatus, P H = 7.6. Increase in weight occurred 

 in S. B. II up to P H = 8.5. For Frohberg Unterhefe H the full curve of acid sensitivity was 

 worked out and the optimum was found to be at P H = 5. — William Crocker. 



1508. Fisher, Ernest Arthur. Contributions to the study of the vegetable proteases. 

 I. Introductory. Biochem. Jour. 13: 124-134. 1919. — This investigation has to do with the 

 determination of proteoclastic enzymes in leaves and other parts of certain farm crops as well 

 as a study of their resemblance, if any, to seed proteases. Fourteen crops were studied, in- 

 cluding barley, oats, maize, rye, red clover, white clover, lucerne, vetch, field beans, peas, 

 buckwheat, white mustard. The Sorenson method of determining proteolysis by formation 

 of free carboxyl groups was employed and a detailed description of technique is given. The 

 author finds that all plants examined showed a protease capable of splitting Witte's peptone 



