X. KFKIX'TS OF DEFICIFATY 2// 



ht'canu' ajjparoiit after extensive assays that the laetic acid bacteria were 

 essentially nnal)le tti utilize pyridoxine to satisfy their \itainin Br, re<niire- 

 nients, the j^rowtli-proniotin^j; actixities previously observed lor this com- 

 pound heinj^ due to the chemical transformation of it, in minute yield, to 

 pyridoxal or pyridoxamine ("pseudopyridoxine") l)y interaction with other 

 ingreilients of the metlium durinj>; autoilaxiufi,.'"' "- Jiecause of this, many 

 of these organisms grow siiboptimally for lack (jf \itamin Be (pyridoxal or 

 pyridoxamine) in media that contain an excess of pyridoxine.""*' "'' When 

 such organisms are grown with small amounts of pyridoxine, therefore, the\' 

 may show metal)olic incapacities due to vitamin Be deficiency which are 

 not a{>j)arent when they are grown with ecjually small amounts of pyridoxal 

 or pyridoxamine. Examples of this behavior will appear later in the dis- 

 cussion. DifTerent lactic acid bacteria also vary in the ease with which they 

 use pyridoxamine and pyridoxal; the former is almost inactive for Lacto- 

 bacillus casri, the latter is highly active."- ^'everal lactic acid bacteria are 

 also known for which only the phosphorylated compounds, pyridoxamine 

 phosphate and pyridoxal phosphate, have high activity ."•*■ "* 



Various Clostridia so far examined,"^" as well as the protozoan organism 

 Tetrahymena geleii,^^^ resemble lactic acid bacteria in utilizing pyridoxal or 

 pyridoxamine far more effecti\'ely than pyridoxine. For most yeasts and 

 molds, on the other hand, all three compounds have very similar activities,"- 

 as they do in animals. 



A deficiency of vitamin Be may produce a variety of effects in micro- 

 organisms in addition to those upon growth. These effects often reflect 

 themselves in an altered quantitative requirement for the vitamin for 

 growth under different environmental conditions. Several examples follow. 

 It was earl}' shown that Streptococcus faccalis, which requires vitamin Be 

 for growth in a medium based on an acid-hj^drolyzed casein supplemented 

 with tryi)tophan, could grow without the \dtamin if D-alanine were added. "^ 

 When grown under .such conditions, little or no vitamin Be was sv'nthe- 

 sized;"'^ however, when cells were grown with \itamin Be and without 

 i)-alanine, the latter amino acid was synthesized and laid down in the 

 cells. "^ It was suggested that vitamin Be (pyridoxal phosphate) served as 



'" E. E. Snell, Proc. Soc. Exptl. Biol. Med. 51, 356 (1942). 



"2 E. E. Snell and A. N. Rimnefeld, J. Biol. Chem. 157, 475 (1945). 



"3 B. C. Johnson, Proc. Soc. Exptl. Biol. .Med. 55, 199 (1944). 



"* W. S. McNutt and E. E. Snell, /. Biol. Chem. 182, 557 (1950). 



"5 D. Hendliii, M. C. Caswell, V. J. Petens, and T. R. Wood, ./. BioL Chen. 186, 647 



(19.50). 

 "^^ M. J. Boyd, M. A. Logan, and A. A. Tytell, J . Biol. Choi. 174, 101.3 (1948). 

 "« G. W. Kid.ler and V. C. Dewey, Arch. Biochcm. 20, 433 (1949); 21, 58 (1949). 

 "^ E. E. Snell, ./. Biol. Chem. 158, 497 (1945). 



"8 J. T. Holden, C. P'urman, and E. E. Sncll, ./. Biol. Chem. 178, 789 (1949). 

 "9 J. T. Holden and E. E. Snell, J. Biol. Chem. 178, 799 (1949). 



