Botany. — "On tlip course of the forimttion of diasixse by A.sper- 

 <lilbis iiiqer", by Prof. F. A. F. C Went. 



(Communicated in the meeting of September 29, 1918). 



It is already a long time that I have intended to cany out an investi- 

 gation on the influence which external conditions exercise on the 

 formation of enzymes, more especially in Aspergillus niqer. 



In a certain sense this would be a continuation of an earlier 

 investigation, which however related to another fungus, Monilia 

 sitophila ^). That my attention has now been turned to Asperqillus 

 niger has its explanation in the fact that Katz has expressed 0[)inions 

 about the formation of enzymes in this fungus, which seem to me 

 hardly probable, but. with regard to which a sure judgment can 

 of course only be formed after a renewed investigation*). Other 

 work has prevented me from cairying out my intention, and seems 

 likely to do so in the near future; moreover in the meantime 

 another investigator, Harat.d Kylin has repeated Katz' investigation 

 by a better method'). It might thus appear that there is no reason 

 for publishing a paper, if my |)reliminary experiments had not given 

 some results, which seem to me of sufiicieni importance to warrant 

 publication even though the investigation is incomplete. 



This preliminary inquiry dealt with the question how the for- 

 mation of diastase by Aspergillus niger depends on its age. It 

 seemed to me that in all comparative investigations insufficient atten- 

 tion has been given to this important point, namely the age of the 

 cultures. Generally cultures of differing nutrition were all after the 

 same length of development compared with one another, it being 

 however evident, that the comparison was here made between 

 unlike things, because the nutritive values of the solutions differed 

 widely. It seemed to me that it would be necessary to trace the 

 whole course of the formation of enzymes in successive intervals 

 of time in each nutrient medium. 



I have not extended the investigation to this length, but have 



1) F. A. F. G. Went, Ueber den Einflusz der Nahrung auf die Enzymbildung 

 durch Monilia sitophila (Mont) Sacc. .lahrb. f. wiss. Bolanik. 36 1901. 



2) J. Katz, Die regulatorische Bildung von Diastase durch PiJze. Jahrb. f. wiss. 

 Botanik. 31 1898. 



3) Harald Kyli.n, Ueber Enzymbildung und Enzymregulation bei einigen Schimmel- 

 pilzen. Jahrb. f. wiss. Bolanik- 53 1914. 



