CAROTENOIDS IN PLANTS 



(iv) Most modern investigations have failed to reveal the presence 

 of acidic carotenoids in the majority of bacteria examined ; this 

 is in contrast vi^ith the situation obtaining in the carotenoid- 

 containing fungi ; 



(v) Chargaff and Lederer's claim ' ^ that y-carotene is probably the 

 typical bacterial carotene cannot, in the light of modern investi- 

 gations, be upheld {see Table 20). 



It was previously thought that anaerobes do not synthesize caroten- 

 oids'®'®^ but, as will be discussed later, Rhodospirillum ruhrum has 

 more recently been found to produce considerable amounts of caro- 

 tenoids anaerobically. 



SCHIZOMYCETES 



Coccaceae. No ^-carotene has been detected in Sarcina lutea in 

 which the specific carotene sarcinene was first detected ; ® ^ also occurr- 

 ing in this organism is a xanthophyll with spectral properties very 

 similar to those of sarcinene ; it has been called sarcinaxanthin. s 2, s 3, s 4 

 Takeda and Ohta ® * obtained 3-4 mg. of sarcinaxanthin from 385 g. of 

 dried organisms ; its behaviour in the partition test indicates that it 

 contained only one hydroxyl group. S. aurantiaca probably contains 

 P- carotene ^ 0, s 5 ^nd lycopene. ® ^ 



Sobin and Stahly®^ have detected spectrographically two new 

 xanthophylls in S. lutea, and one in *S. aurantiaca which may also 

 contain zeaxanthin. ® ^ S. flavia contains one, and Micrococcus luteus 

 both the xanthophylls elaborated by S. lutea. According to Nakamura ® * 

 S. lutea contains a xanthophyllic (? sarcinaxanthin) ester. S-carotene 

 and rubixanthin were detected in every strain of Staphylococcus aureus 

 examined by Sobin and Stahly, ® ^ but they could not detect zeaxanthin 

 which had previously been reported in Staph, aureus. ® ^ y-carotene, 

 lycopene, rubixanthin, lutein (xanthophyll) and rhodoxanthin are 

 stated to be present in Micrococcus tetragenus. The type of pigment 

 varies according to the type of culture. The yellow type contains lutein, 

 the mucoid-pink type lycopene, and the pink type rhodoxanthin ; the 

 pink-yellow type and brown type, on the other hand, appear to contain 

 y-carotene and rubixanthin. ' ' 



Bacteriaceae 



In 1893 Lankester®' found a red pigment which he named hacterio- 

 purpurin in Bact. rubescens. Molisch ® ® reinvestigated this pigment and 

 found that it had two components, a- and p-bacteriopurpurin. Flavo- 

 bacterium arborescens contains five pigments, one of which is probably 



119 



