PANTOTHENIC ACID 



containing ten times as much as the basal medium. ^^ Aspergillus 

 niger, Penicillium wolkmanni, two unnamed species of Penicillium, 

 Rhizopus suinus and Rh. nigrans also synthesised pantothenic acid.^^ 

 One strain of Neurospora produced considerable amounts of panto- 

 thenic acid in presence of pantolactone and ^-alanine, and very little 

 in their absence, whilst another strain, differing from it by a single 

 gene, produced no pantothenic acid in either instance.^^" 



Yeasts 



Pantothenic acid was essential for the growth of a number of 

 yeasts, including Candida pseudotropicalis, Mycoderma valida, Sac- 

 charomyces cerevisiae, S. cerevisiae var. ellipsoideus, S. chodati, S. 

 fragilis, S. logos, S. macedoniensis, S. oviformis, S. tubiformis, Sac- 

 charomycodes ludwigii, Schizosaccharomyces pombe, Zygosaccharomyces 

 barkeri, Z. mandshuricus, Z. nadsoni, Z. pastori, Z. priorianus, Z, 

 felsineus, Z. marxianus, Z. variabilis, Z. japonicus, Torulopsis sphaerica, 

 Saccharomyces chevalieri, S. behrensianus , S. anomalus belgicus, S. 

 bacillaris, S. exiguus, Torula thermantitoneum, T. collicidosa, T. cremoris 

 and Kloeckera brevis.^* ^^ 



The growth of a strain of S. cerevisiae was stimulated by an amount 

 of pantoic acid equal to 600 times that required to combine with the 

 ^-alanine present when suboptimal amounts of the latter were em- 

 ployed.^^ No stimulation occurred when the acid was added after 

 an interim period. Pantoic acid appeared to have a stimulative action 

 of its own, which could be demonstrated in presence of pantothenic 

 acid or of optimal amounts of ^-alanine. Pantolactone had no such 

 effect. The effect of pantoyltaurine on the Gebriider-Mayer strain of S. 

 cerevisiae, which gives good growth only in the presence of pantothenic 

 acid or j8-alanine, was tested by E. E. Snell.^' He found, as with L. 

 arabinosus and other exacting bacteria, that pantoyltaurine inhibited 

 growth induced by pantothenic acid, and that the inhibition was re- 

 versed by additional pantothenic acid. Growth induced by /3-alanine 

 was not inhibited by pantoyltaurine, nor was it affected by taurine. 



In presence of an excess of pantothenic acid, yeast cells utilise it 

 but do not synthesise additional amounts. At lower concentrations, 

 the amount of growth is proportional to the pantothenic acid concen- 

 tration, whilst at still lower concentrations mutants capable of syn- 

 thesising the vitamin are produced.^^" 



Other Micro-organisms 



Addition of calcium pantothenate to a diet low in aneurine, ribo- 

 flavine and pantothenic acid increased the number of oocysts elim- 

 inated by rats infected with Eimeria nieschulzi. The further addition 



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