X. EFFECTS OF DEFICIENCY 485 



were increased by the addition of vitamin B12. The final total amount of 

 oxj'^gen uptake was not influenced but only the rate. The amount of vitamin 

 B12 involved in the process was extremely small; approximately only 2 

 molecules per bacterial cell. 



4. Forms of Vitamix Bi> with Greater Potency for 

 Microorganisms Than for Animals 



The first report of forms of vitamin B12 which are more active for micro- 

 organisms than for animals was that of Coates et al." These workers found 

 that both dried rumen contents and dried calf feces with L. leichmannii 

 4797 18 gave assay values approximately five times as high as the values 

 obtained by chick growth, whereas values obtained with the E. coli assay' ^ 

 were about twenty times as high. The extracts assayed were treated with 

 cyanide to convert all forms to the cyano derivatives. Using a concentrate 

 prepared by adsorbing a water extract of calf feces on charcoal and eluting 

 with hot 75 % acetone, paper chromatography in the presence of cyanide 

 showed the existence of two forms active for E. coli besides vitamin Bi2.^° 

 These were called fractions A and B. Fraction A was later^' shown to be 

 about five times as potent for Euglena gracilis and E. coli as for L. leich- 

 mannii 4797. Amounts up to 200 7 per kilogram of diet were inactive for 

 chicks. For chicks fraction A antagonized one-fifth its own weight of vita- 

 min B12.-- Fraction B was inactive for chicks orally, and both fraction A 

 and B were about one-tenth as active as vitamin B12 when injected intra- 

 muscularly in chicks. In one pernicious anemia patient, fraction A appeared 

 to have only slightly less activity than vitamin B12. Further chromato- 

 graphic studies'^' revealed the presence of a fourth fraction, C, which was 

 about fifteen times as active for E. coli as for L. leichmannii 4797 and with 

 only slight activity for Euglena gracilis. It should be emphasized that frac- 

 tions A, B, and C all contain cyanide and, therefore, differ from vitamin 

 B12 in some other portion of the molecule. 



Pfiffner ei al.-^ have reported that an organism, as yet incompletely 

 identified, isolated from bovine rumen contents produces sLx cobalt-contain- 



" M. E. Coates, J. E. Ford, G. F. Harrison, S. K. Kon, J. W. G. Porter, W. F. J. 



Cuthbertson, and H. F. Pegler, Biochem. J. 49, Ixvii (1951). 

 '8 H. R. Skeggs, H. M. Nepple, K. A. Valentik, J. W. Huflf, and L. D. Wright, /. Biol. 



CAew. 184, 211 (1950). 

 '' C. J. Bessell, E. Harrison, and K. A. Lees, Chemistry & Industry 1950, 561. 

 20 J. E. Ford, S. K. Kon, and J. W. G. Porter, Biochem. J. 50, ix (1951). 

 -' J. E. P^ord and J. \V. G. Porter, 304th Meeting, Biochemical Society, London, 



1952; Biochem. J. (In press). 

 " M. E. Coates, J. E. Ford, G. F. Harrison, S. K. Kon, and J. W. G. Porter, 304th 



IMeeting, Biochemical Society, London, 1952; Biochem. J. (In press). 

 " J. J. Pfiffner, D. G. Calkins, R. C. Peterson, D. D. Bird, V. McGlohon, and R. 



W. Stipek, Abstr. Papers 120th Meeting, Am. Chem. Soc. p. 22C (1951). 



