890 XIV. NUTRITIONAL VALUE OF FATS 



thesis of biotin. It is therefore apparent that biotin normall}^ functions 

 in bacterial meta])olism by lounging about the S3nithesis of oleic acid. 



Although oleic acid functions as a substitute for biotin with many 

 bacteria in in vitro culture tests, apparently it does not behave in the same 

 manner when injected into animals. For example, Trager-'*^ reported 

 that oleic acid injected intramuscularly into chicks did not have the same 

 effect in reducing biotin deficiency produced by the ingestion of avidin 

 from raw egg white as had biotin or the fat-soluble fraction from hydrolyzed 

 plasma. Moreover, Williams and Fieger^^'- demonstrated that the lipids 

 from rice polishings, which have a biotin-like activity in the case of L. 

 casei and L. arabinosiis, will not reduce the biotin-deficiency symptoms in 

 white leghorn chicks. Hutchings and Boggiano-^^ reported that the 

 addition of sodium oleate to a medium containing a yeast extract allowed 

 for maximum growth with se^-eral lactobacilli. The amount of sodium 

 oleate producing maximum growth varied with each organism. Increasing 

 amounts (500 to 4000 ug. /lO ml.) proved toxic for Locfohacillus leichmannii 

 and L. plaritarimi . 



b. Comparative Potencies of Octadecenoic Acids. In addition to oleic 

 acid, a large number of isomers, both geometric and positional, can serve 

 as adjuncts in the growth of bacteria. In the first place the /rans-isomer 

 of oleic acid, namely elaidic acid, has been found by a number of work- 

 gj.g245-249 ^Q }jg approximately as active as oleic acid. On the other hand, 

 Axelrod and co-workers'-^^ assigned a much lower biopotency to elaidic 

 acid, and Williams and Fieger'-^^ observed a somewhat greater effect 

 than was the case with oleic acid. The activity of m-octadecenoic acids 

 is not markedly influenced l)y the location of the double bond. Thus, 

 petroselinic acid (G-octadecenoic acid),--'^''"'-'*^ palmitoleic acid {cis-9- 

 hexadecenoic acid),-^'^ vaccenic acid (/rans-ll -octadecenoic acid),^^^'-^^ 

 as-12-octade('enoic acid,-""^ and cfs-8-octadecenoic acid-^^all exert about 

 the same growth-stimulating effect as does oleic acid, although the cis- 

 8 acid appeared to have a somewhat greater effect. On the other hand, 

 myristoleic acid (cis-4-octadecenoic acid) has been reported to be inactive, 



2« W. Trager, /. Biol. Chem., 176, 133-146 (1948). 



2^^ B. L. Hutchings and E. Boggiano, /. Biol. Chem., 169, 229-230 (1947). 



245 B. W. Boughton and M. R. Pollock, Biochem. J., 50, xxxi (1952). 



2« M. R. Pollock, G. H. Howard, and B. W. Boughton, Biochem. J., U, lii (1949). 



''« M. R. Pollock, G. H. Howard, and B. W. Boughton, Biochem. J., 45, 417-422 

 (1949). 



2« A. E. Axelrod, K. Hofmann, and B. F. Daubert, ./. Biol. Chem., 169, 761-762 

 (1947). 



2" A. L. S. Cheng, S. M. Greenberg, H. J. Deuel, Jr., and D. Melnick, /. Biol. Chem., 

 i5£, 611-622 (1951). 



