314 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 10 



re- 



in fruiting. In connection with these carbon compounds re- 

 ferred to, (NH<),S04 and (NH^PO, were found superior to 

 asparagin and glycine as N sources. The energy requirements 

 for the amino acids were higher because of the necessary deamid- 

 ization. The energy quotient for asparagin was raised by the 

 addition of free H 2 SO ( to the culture fluid. 



In his 1919 work Boas showed also that the rate of absorption 

 of a compound was proportional to its extent of dissociation ; for 

 example, the highly dissociated NH« salts of strong mineral acids 

 were utilized before glycine, acid amides, and peptones. This 

 relation held in spite of strong acid formation and the consequent 

 production of soluble starch and inhibition of sporulation. His 

 1922 article gave data showing that on media containing 

 spectively, levulose, sucrose, dextrose, maltose, and galactose, 

 decreasingly in order of the sugars listed, Aspergillus rriger was 

 capable of forming soluble starch. There appeared to be a close 

 connection between diastase formation, sporulation, and hydrion 

 concentration. In contrast to the behavior of Aspergillus niger, 

 A. Oryzae on maltose caused soluble starch formation but on 

 levulose produced none. 



Waksman ('18, '19, '20), in his extensive studies with soil or- 

 ganisms, particularly the Actinomyces, gave due attention to the 

 nitrogen relations. His 1918 work with several species of Asper- 

 gillus, Citromyces, Penicillium, and Actinomyces, and Bacterium 

 mycoides showed that such rapidly growing molds as Aspergillus 

 and Penicillium on Czapek's solution, with peptone or casein as 

 the N source, produced an abundance of ammonia which gradu- 

 ally increased with the duration of incubation; amino nitrogen, 

 on the other hand, tended to decrease, indicating use by the 

 organisms. The slower-growing Actinomyces and Bacterium 

 mycoides brought about a large accumulation of amino nitrogen 

 and a relatively small accumulation of ammonia. Another 

 group, represented by Citromyces spp., favored the accumulation 

 of both forms of N in relatively large amounts. In the work 

 with Aspergillus niger it was shown that this accumulation of 

 NH a took place both in the absence and presence of sugar, but 

 the sugar depressed the rate of production. In the presence of 

 sugar the curve for NH, accumulation followed remarkably the 



