INULASE FORMATION IN ASPERGILLUS 79 



formed when culture media containing trehalose are used but it 

 does not diffuse out into the culture media; the glucose formed by 

 it, however, does diffuse out and may be detected by appropri- 

 ate means. Invertase is formed when the culture medium con- 

 tains sucrose, glucose, maltose, glycerin, acetic acid, lactic acid, 

 malic acid or peptone. When glycerin is present in the culture 

 medium, starch is transformed to glucose as in the usual case, 

 but in the process no maltase is formed, as is shown by the fact 

 that maltose added to the culture medium remains unchanged. 

 Went concludes that in general the secretion of enzymes is not 

 to be considered a hunger phenomenon, as so many workers con- 

 tend, since there is generally'' more enzyme secretion in those 

 fungi which are well nourished. 



The excellent work of Dox (1910) on the enzymes of Penicil- 

 lium and Aspergillus includes much work of a truly physiological 

 character. He studied principally Penicillium caviemberti grow- 

 ing cultures of the fungus on both Raulin's and Czapek's media. 

 These media were found not to cause a hydrolysis of the carbohy- 

 drates of the culture medium, a result which no doubt has af- 

 fected the results obtained by many other workers. Cultures 

 were grown at laboratory temperature in Erlenmeyer flasks. 

 Dox employs the ''acetonedaurhefe" method of Albert and 

 Buchner for the preparation of his enzyme powder and consid- 

 ers only the enzymes of the mycelium at the time of its 

 sporulation. 



Dox finds that nucleic acid is decomposed by enzyme prepa- 

 rations from Penicillium camemberti ''irrespective of the pres- 

 ence of nucleic acid in the culture medium." These results differ 

 from^ those of Iwanoff (1903), who finds that the formation of 

 nuclease is dependent on the presence of nucleic acid in the cul- 

 ture medium and that no nuclease is formed on a medium con- 

 taining only inorganic salts and carbohydrates. 



Penicillium camemberti was found by Dox to have the power 

 of hydrolyzing fat under proper conditions, but it was not deter- 

 mined whether or not the presence of fats in the culture medium 

 causes an increase in the amount of lipase formed. Cultures 

 grown on sucrose were found to have a very feeble lipolytic 



