THE PIGMENTS OF MICRO-ORGANISMS 387 



A. Cellular Pigments not colouring the medium. 

 I. Soluble in chloroform. 



(a) Soluble in alcohol — 



(1) Carotenoid — 



(a) Red, e.g. x^^g^^^^^^^^ ^^ 



BJwdococcus, sulphur 



bacteria, Actinomyces, 



Torula. 

 (jS) Orange, e.g. pigments of 



Staph, aureus, Sarcina 



aurantlaca. 

 (y) Yellow, e.g. pigments of 



Staph, aureus, Staph. 



citreus, Sar. lutea. 



(2) Xo 13 -carotenoid — 



(a) Colour change with acids 

 and alkalies, e.g. pro- 

 digiosin, red in acid, 

 yellow in alkali ; bac- 

 terio-chlorin, the green 

 pigment of sulphur 

 bacteria ; the red and 

 yellow pigments of 

 Fusarium, Aspergillus, 

 Penicillium. 

 (fi) No colour change with 

 acids or alkalies — 



(i) Fluorescent, e.g. 

 pigments of 

 some species of 

 Aspergillus. 

 (ii) Non - fhiorescent, 

 e.g. Flavobacte- 

 rium brunneum. 



