390 BACTERIOLOGICAL CHEMISTRY 



OCH3 CH3 

 (CH3)2C=CH.C=CH.C = 



(CH3)2C = CH.CH = CH.C = CH.CH = 

 OCH, 



CH3 

 CH.CH = CH.C 



CH.C= CH.CH" 

 CH, 



a=CH 



I 



a=CH 



rhodopurpiirin ; flavorhodin, a hydrocarbon ; and j3- 

 carotene. 



Sarcina lutea produces bacterioxanthophyll ; a crys- 

 talline xanthophyll pigment, sarcina-xanthine, m.p. 

 149° C, with absorption maxima at 480, 451 and 423 m/x 

 in chloroform, has been isolated from 8. lutea ; 8. 

 aurantiaca gives j8-carotene and zeaxanthin ; 8taph. 

 aureus gives zeaxanthin as the only pigment ; M. phlei 

 gives lutein (a xanthophyll ester), kryptoxanthin and a-, 

 j8- and y-carotenes ; M. leprce gives a pigment, leprotin, 

 which is very like j8-carotene ; some strains of Myco- 

 bacterium have been shown to produce four carotenoid 

 pigments when grown on media containing mineral oil 

 as the sole carbon source. Two of the pigments had 

 vitamin A activity and one was shown to be astacin ; 

 8pirillum ruhrum gives the purple pigment, spirillo- 

 xanthin, C48H66O3, containing one hydroxyl group and 

 fifteen double bonds, and also other carotenoid pigments. 

 Bacterium cocovenenans gives a yellow pigment, toxo- 

 flavin, C6H6O4N2, which is isomeric with methylxanthine. 

 Anaerobic bacteria apparently do not produce carotenoid 

 pigments. 



The purple sulphur bacteria give bacteriopurpurin, 

 which is a mixture of the red pigment, bacterioerythrin, 

 and the green pigment bacteriochlorin or bacterio- 

 chlorophyll, C55H7206N4Mg.H20, which is very similar to 

 plant chlorophyll ; on removal of the magnesium it yields 

 bacteriophseophytin. Bacteriochlorophyll is like chloro- 

 phyll -a but contains two more hydrogen atoms and has 



