CAROTENOIDS IN PLANTS 



that this coloration is due to the production of a carotenoid but no 

 proof of this has been supphed. Addition of steroids has no effect on 

 pigmentation in either Rhodotorula or Saccharomyces, but oxygenation 

 stimulates pigment production in the latter. 



Luteraan and Choay * ' report that when an unspecified Penicillium 

 is cultured on a medium completely free from aneurin, it produces a 

 considerable amount of carotenoids in place of the usual non-carotenoid 

 pigment. Full details of this investigation are not yet available. 



Goodwin and Willmer * * have shown that Phycomyces produces very 

 much less carotene on a medium buffered at pH 7 than on media 

 held at lower pH values. 



Table 17 



The effect of Diphenylamine (1/30,000) on the Carotenoid Production 

 by Phycomyces blakesleeanus. 



* The exact increase in phytoene is difficxilt to measure in presence of DPA. 



Inhibition Studies. Turian, « ^ developing the original qualitative 

 observations of Kharasch, Conway, and Bloom « * that chromogenesis 

 in many bacteria and fungi is inhibited in the presence of dipheny- 

 lamine, recently showed that this substance, at a concentration of about 



115 



