CAROTENOIDS IN PLANTS 



Accordftig to Mahdihassan ^ ^ ^ symbiotic carotenoid production 

 occurs in Cicadella viridis ; two types of bacteria occur, one type 

 producing sarcinene and the other [^-carotene. 



iOOO 



2000 



lOOO 



400 



460 480 



Fig. 20. — The absorption spectra of 



(o) rhodopin in ethanol. 



(b) rhodoviolascin in hexane. 



(c) chrysophlein in ethanol. 



(a) and (b) redrawn from Karrer, P., arxi Solmssen, U. (1943) Helv. chim. 



Acta. 26, 118. 

 (c) redrawr) from Tunan, G. (1950) Helv. chim. Acta, 133, 1303 

 Note. — The E|'j/^ scale does not apply to chrysophlein, which has not 

 yet been obtained crystalline. 



FORMATION IN BACTERIA 



(i) Carbon and Nitrogen sources in media 



Ingraham, Fred and Steenbock^"' found that glycerol was the 

 best carbon source for carotenoid production in bacteria ; this is in 

 agreement with the finding on fungi {see p. 110), Studying My cobact. 

 phlei in detail, Ingraham and Steenbock'^ demonstrated that this 

 bacterium utilizes wopropanol and ethylene glycol almost as well as 

 it does glycerol. Variations in the nitrogen source, by replacing 

 asparagine by ammonia, urea, or peptone had no effect on pigment 

 production providing the pH of the medium was controlled. Flavobact. 

 arborescens produced more carotenoids on a liquid medium con- 

 taining glycerol or glucose than on an agar medium. Haas and 



123 



