FATS AS ESSENTIAL DIETARY COIMl'UNENTS 873 



pro\'ed too toxic to the host for practical use, they were highly elTective in 

 reducing or eliminating African pathogenic trypanosomes from the blood 

 stream of experimental animals. 



The interrelation of fats and microorganisms has several aspects. In 

 contradistinction to the bactericidal effect of fats and fatty acids, a number 

 of workers have observed synthesis of fatty acids bj^ bacteria and fungi, 

 and also stimulation of bacterial growth by certain fatty esters. The 

 degree of concentration is sometimes the determining factor, and gro\\i;h 

 conditions also have a bearing. For example, while Rittenberg et al.^*'' 

 observed the anaerobic toxicity of certain fatty acids for Escherichia coli, 

 these workers^^^ also found that aerobic bacteria have the ability to oxidize 

 Cg and C)o fatty acids. Glucose-groA\ii cells of Serratia marcescens (also 

 called Erythrohacillus prodigiosus) , a non -pathogenic bacterial organism 

 which produces a red pigment, is able to oxidize all straight-chain saturated 

 fatty acids from acetic through myristic, with the exception of propionic 

 and valeric acids. 



Hesse'*^ reviewed the findings of a number of workers who observed the 

 synthesis of fat by various yeasts and penicillia (fungi), including among 

 many others the ascosporogenous yeast {Endomijces vernalis), the milk 

 mold {Oidium lactis), a mold from decaying vegetable matter {Aspergillus 

 fischeri (fumigatus)) , the non -pathogenic fungus from feces (Mucor mu- 

 cedo), the yeast-like fungus {Torida utilis), which forms fat rapidly from 

 alcohol, the ascomycetous fungus from brewer's yeast (Saccharomyces 

 cerevisiae) , the pigment-producing fungus {Rhodotorula glutinis), which 

 forms a reddish pigment resembling carotene, the plant pathogen mold 

 causing flax blight {Fusariimi lini), etc. The fat produced b}^ these micro- 

 organisms contains both saturated and unsaturated fatty acids (palmitic, 

 stearic, oleic, linoleic, linolenic) ; oleic acid is the main constituent. 



Ramakrishnan and Banerjee^^" found that the molds grown on sesame 

 (Sesamum indicum) and on coconut developed considerable lipolytic activity. 

 The blue-green mold (Penicillium chrysogenum Si) and the yellow-green 

 \'ariet3^ {Aspergillus flavus Se) grown on sesame oil, showed the greatest 

 activity. 



Goldman and Rayman^'^' studied the hydrolysis of fats bj^ a saprophytic 

 bacterium in baker's yeast {Pseudomonas flumcscens), named for the 



'« S. C. Rittenberg, J. H. Silliker, and M. E. Ward, Bacteriol. Proc, 1950 Ahst., 145. 

 i« J. H. Silliker and S. C. Rittenberg, J. BuderioL, 61, 653-659, 661-673 (1951). 

 '" A. Hesse, Advances in Enzymol, 9, 653-704 (1949). 



1*" C. V. Ramakrishnan and B. N. Banerjee, Arch. Biochem. Biophys., 37, 131-135 

 (1952). 



'ii W. L. (Joldnian and M. M. Ruyniau, Food Resmnh, 17, 326-337 (1952). 



