Heliobacterium chlorum

In the BChl g containing heliobacteria Heliobacillus mobilis and Heliobacterium chlorum symmetric dimers for the primary donor radical cation PgJ5 have been found based on EPR and ENDOR data.85 This symmetric dimer is consistent with the homodimeric structure of the RC. The same reason was invoked to explain the high symmetry of the donor radical-cation Pgg5 in green sulfur bacteria, which is made up from a BChl a dimer.86 For a review see reference 87. Note that these RCs belong to the type I RCs. 

Fig. 1. Dendrogram of relationships among photosynthetic prokaryotes and their relatives, after Stackebrandt and Woese [2], Five bacterial phyla [1] containing photosynthetic members are shown. The exact relationship of Heliobacterium chlorum to the gram-positive bacteria is not yet known. Not shown are the other five phyla without known photosynthetic-members peptidoglycan-less bacteria bacteroids, cytophagas and flavobacteria spirochaetes and leptospiras bdellovibrios, myxococci, and certain S and SOj reducers and Deinococcus. PS = photosynthetic for further explanation, see text.

In the recently discovered photosynthetic bacterium Heliobacterium chlorum, which has a BChl g complex as primary donor, the primary acceptor is also a ferredoxin-type molecule with g values 2.04, 1.94 and 1.88 [40]. An earlier acceptor could be photoaccumulated at very low (< —620 mV) redox potential. It had a near-Gaussian EPR line at g = 2.0038 with AB = 15 G at X-band and 18 G at Q-band [40]. 

H Gest and JR Favinger (1983) Heliobacterium chlorum, an anoxygenic brownish-green photosynthetic bacterium containing a new form ofbacteriochlorophyllArch Microbiol 136 11-16... 

TRIPLETS IN THE ANTENNA AND REACTION CENTRE OF HELIOBACTERIUM CHLORUM AT LOW TEMPERATURE... 

The heliobacteria are a seperate group of photosynthetic bacteria which contain bacteriochloro-phyll g as their major pigment (1). Only three species have been isolated so far Heliobacterium chlorum. Heliobacillus mobilis and Heliospirilum gestii. 

Excitation Transfer and Charge Separation in Heliobacterium Chlorum at 15 K 185... 

Triplets in the Antenna and Reaction Centre of Heliobacterium Chlorum at Low Temperature 189... 

Triplet-minus-singlet Absorbance Difference Spectroscopy of Heliobacterium chlorum Monitored with Absorbance-detected Magnetic Resonance J. Vrieze, E.J. van de Meent, A.J. Hoff. 67... 

Brockmann, H. Jr and Lipinski, A. (1983) Bacteriochlorophyllg. A new bacteriochlorophyll from Heliobacterium chlorum. Arch. Microbid., 136, 17-19. 

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