344 BOTANICAL GAZETTE [October 



With glycerin, alcohol, or peptone as sources of carbon, no fumaric acid is 

 produced. The fact that fumaric acid here occurs as an intermediate 

 product in the metabolism of sugar suggests that unsaturated acids in 

 higher plants may result from carbohydrate metabolism. That a close 

 relation exists between the higher unsaturatied acids and carbohydrates in 

 plant metabolism has been generally conceded by plant physiologists since 

 the work of Maquenne. 



That many fungi and bacteria are able to utilize fats has been shown by 

 several investigators. A further contribution to the subject has been made by 

 Ohta, 15 who studied the decomposition of the fat of horse liver caused by five 

 forms of fungi obtained by exposing culture plates in the laboratory. The 

 forms were Cladosporium herbarum, Penicillium glaucum, Aspergillus glaucus, 

 A. nidulans, and Actinomucor repens. All of these caused the disappearance 

 of fat from the ground sterilized liver tissue. Actinomucor was the most 

 active, causing the disappearance of over 60 per cent of the fat in three 

 weeks. Of the others, Aspergillus used 17-20 per cent, Cladosporium 14 per 

 cent, and Penicillium 6-8 per cent. Attempts to grow Actinomucor on culture 

 solutions containing fat as the only source of carbon, in order to study the 

 mode of decomposition of the fat, were unsuccessful. The paper contains 

 detailed notes on the methods and precautions to be observed in making fat 

 determinations in work of this kind. 



Another contribution to the subject of the utilization of fat by fungi has 

 been made by Roussy, 16 who experimented with the following forms: Absidia 

 glauca, Circinella umbellata, Mucor mucedo, Phycomyces nitens, Rhizopus 

 nigricans, Sporodinia grandis, Morteirella candelabrum, Aspergillus flavus, 

 Citromyces glaber, Penicillium luteum, Sterigmatocystis nigra, and Sporotrichum 

 bombyceum. All of these grew well on fats and oils of various kinds. To 

 determine if it was the fatty acid or the glycerine which was utilized, cultures 

 were made in Raulins solution in combination with oleic, palmitic, or stearic 

 acid or glycerine. It was found that the fungi thrived well on the fatty acids, 

 but only Aspergillus and Penicillium grew on glycerin solutions. 



Reichel, studying the effects of acetic acid and its salts on a form of Peni- 

 cillium, has rediscovered the fact that the toxicity of that acid is mainly due 

 to the action of the undissociated molecule. He finds that acetic acid is poison- 

 ous in much lower concentrations than those at which the strong mineral acids 

 are toxic, but, owing to its slight dissociation, its toxicity cannot be attributed 

 to the hydrogen ion. At the same time, the salts of acetic acid, which are highly 

 dissociated, are not poisonous, hence the acetate ion is not poisonous. The 

 toxicity of acetic acid, therefore, must be attributed to the molecule as a whole. 



immelpilze 



nf 



bst 



dem Verhalten des Organfettes gegen Faulniss. Biochem. Zeitschr. 31: i77^ x 94- I 9 11 - 



16 Roussy, A., Sur la vie des Champignons dans les acides gras. Compt. Rend. 

 153:884-886. 191 1. 



