SOME FACTORS AFFECTING INULASE FORMATION 



IN ASPERGILLUS NIGER 



V. H. YOUNG 



State University of Iowa, Iowa City, Iowa 



A. INTRODUCTION 



The purpose of the work herein described has been to investi- 

 gate in a quantitative as well as qualitative way the formation 

 of an enzyme in a living organism. For such a study certain 

 saprophytic fungi are especially suited since environmental fac- 

 tors can be more definitely controlled with them than with other 

 plants. 



The work was done in the Laboratories of Plant Physiology of 

 the University of Wisconsin and the author is indebted to Prof. 

 J. B. Overton for facilities, aid and encouragement. 



The work of Katz, Went, Knudson, Dox, Kylin, and others on 

 the quantitative and qualitative regulation of enzymes in the 

 fungi has served as a basis for the work and reference will con- 

 stantly be made to certain phases of their work. It is proposed 

 to study the effect of age and carbohydrate nutrition on the 

 enzyme content of a fungus. The work has been confined almost 

 entirely to the as yet little known enzyme ^'inulase," and prac- 

 tically all the investigations have been with Aspergillus niger. 



B. REVIEW OF LITERATURE 



The early literature dealing with fungal enzymes as well as the 

 more recent literature is so completely reviewed in the publi- 

 cations of the above mentioned authors that it has not been 

 thought necessary to consider in detail any of the literature ex- 

 cept that definitely germane to the subject of the investigation. 



The presence of inulin in plants has been known for many 

 years. Green (1888) was the first to isolate an enzyme which 

 would hydrolyze inulin. He called the enzyme, which he ex- 



75 



THE PLANT WORLD, VOL. 21, NO. 4 

 APRIL. 1918 



