S. Takaichi et al., THE MAJOR CAROTENOID IN ALL KNOWN SPECIES OF HELIOBACTERIA IS THE C-30 CAROTENOID 4,4'-DIAPONEUROSPORENE, NOT NEUROSPORENE, Archives of microbiology, 168(4), 1997, pp. 277-281
The carotenoids of five species of heliobacteria (Heliobacillus mobili
s, Heliophilum fasciatum, Heliobacterium ch[or-um, Heliobacterium mode
sticaldum, and Heliobacterium gestii) were examined by spectroscopic m
ethods, and the C-30 carotene 4,4'-diaponeurosporene was found to be t
he dominant pigment; heliobacteria were previously thought to contain
the C-40 carotenoid neurosporene. In addition, trace amounts of the C-
30 diapocarotenes diapolycopene, diapo-zeta-carotene, diapophytofluene
, and diapophytoene were also found. Up to now, diapocarotenes have be
en found in only three species of chemoorganotrophic bacteria, but not
in phototropic organisms. Furthermore, the esterifying alcohol of bac
teriochlorophyll g from all known species of heliobacteria was determi
ned to be farnesol (C-15) instead of the usual phytol (C-20) Heliobact
eria may be unable to produce geranylgeranyol (C-20).