@article {604,
	title = {N2-dependent growth and nitrogenase activity in the metal-metabolizing bacteria, Geobacter and Magnetospirillum species.},
	journal = {Environ Microbiol},
	volume = {2},
	year = {2000},
	month = {2000 Jun},
	pages = {266-73},
	abstract = {Cells of Geobacter metallireducens, Magnetospirillum strain AMB-1, Magnetospirillum magnetotacticum and Magnetospirillum gryphiswaldense showed N2-dependent growth, the first anaerobically with Fe(III) as the electron acceptor, and the latter three species microaerobically in semi-solid oxygen gradient cultures. Cells of the Magnetospirillum species grown with N2 under microaerobic conditions were magnetotactic and therefore produced magnetosomes. Cells of Geobacter metallireducens reduced acetylene to ethylene (11.5+/-5.9 nmol C2H4 produced min(-1) mg(-1) cell protein) while growing with Fe(III) as the electron acceptor in anaerobic growth medium lacking a fixed nitrogen source. Cells of the Magnetospirillum species, grown in a semi-solid oxygen gradient medium, also reduced acetylene at comparable rates. Uncut chromosomal and fragments from endonuclease-digested chromosomal DNA from these species, as well as Geobacter sulphurreducens organisms, hybridized with a nifHDK probe from Rhodospirillum rubrum, indicating the presence of these nitrogenase structural genes in these organisms. The evidence presented here shows that members of the metal-metabolizing genera, Geobacter and Magnetospirillum, fix atmospheric dinitrogen.},
	keywords = {Acetylene, DNA, Bacterial, Ethylenes, Genes, Bacterial, Iron, Nitrogen Fixation, Nitrogenase, Oxidation-Reduction, Oxidoreductases, Proteobacteria, Rhodospirillaceae},
	issn = {1462-2912},
	author = {Bazylinski, D A and Dean, A J and Sch{\"u}ler, D and Phillips, E J and Lovley, D R}
}
@article {645,
	title = {Novel processes for anaerobic sulfate production from elemental sulfur by sulfate-reducing bacteria.},
	journal = {Appl Environ Microbiol},
	volume = {60},
	year = {1994},
	month = {1994 Jul},
	pages = {2394-9},
	abstract = {Sulfate reducers and related organisms which had previously been found to reduce Fe(III) with H(2) or organic electron donors oxidized S to sulfate when Mn(IV) was provided as an electron acceptor. Organisms catalyzing this reaction in washed cell suspensions included Desulfovibrio desulfuricans, Desulfomicrobium baculatum, Desulfobacterium autotrophicum, Desulfuromonas acetoxidans, and Geobacter metallireducens. These organisms produced little or no sulfate from S with Fe(III) as a potential electron acceptor or in the absence of an electron acceptor. In detailed studies with Desulfovibrio desulfuricans, the stoichiometry of sulfate and Mn(II) production was consistent with the reaction S + 3 MnO(2) + 4H-->SO(4) + 3Mn(II) + 2H(2)O. None of the organisms evaluated could be grown with S as the sole electron donor and Mn(IV) as the electron acceptor. In contrast to the other sulfate reducers evaluated, Desulfobulbus propionicus produced sulfate from S in the absence of an electron acceptor and Fe(III) oxide stimulated sulfate production. Sulfide also accumulated in the absence of Mn(IV) or Fe(III). The stoichiometry of sulfate and sulfide production indicated that Desulfobulbus propionicus disproportionates S as follows: 4S + 4H(2)O-->SO(4) + 3HS + 5 H. Growth of Desulfobulbus propionicus with S as the electron donor and Fe(III) as a sulfide sink and/or electron acceptor was very slow. The S oxidation coupled to Mn(IV) reduction described here provides a potential explanation for the Mn(IV)-dependent sulfate production that previous studies have observed in anoxic marine sediments. Desulfobulbus propionicus is the first example of a pure culture known to disproportionate S.},
	issn = {0099-2240},
	author = {Lovley, D R and Phillips, E J}
}
@article {662,
	title = {Novel mode of microbial energy metabolism: organic carbon oxidation coupled to dissimilatory reduction of iron or manganese.},
	journal = {Appl Environ Microbiol},
	volume = {54},
	year = {1988},
	month = {1988 Jun},
	pages = {1472-80},
	abstract = {A dissimilatory Fe(III)- and Mn(IV)-reducing microorganism was isolated from freshwater sediments of the Potomac River, Maryland. The isolate, designated GS-15, grew in defined anaerobic medium with acetate as the sole electron donor and Fe(III), Mn(IV), or nitrate as the sole electron acceptor. GS-15 oxidized acetate to carbon dioxide with the concomitant reduction of amorphic Fe(III) oxide to magnetite (Fe(3)O(4)). When Fe(III) citrate replaced amorphic Fe(III) oxide as the electron acceptor, GS-15 grew faster and reduced all of the added Fe(III) to Fe(II). GS-15 reduced a natural amorphic Fe(III) oxide but did not significantly reduce highly crystalline Fe(III) forms. Fe(III) was reduced optimally at pH 6.7 to 7 and at 30 to 35 degrees C. Ethanol, butyrate, and propionate could also serve as electron donors for Fe(III) reduction. A variety of other organic compounds and hydrogen could not. MnO(2) was completely reduced to Mn(II), which precipitated as rhodochrosite (MnCO(3)). Nitrate was reduced to ammonia. Oxygen could not serve as an electron acceptor, and it inhibited growth with the other electron acceptors. This is the first demonstration that microorganisms can completely oxidize organic compounds with Fe(III) or Mn(IV) as the sole electron acceptor and that oxidation of organic matter coupled to dissimilatory Fe(III) or Mn(IV) reduction can yield energy for microbial growth. GS-15 provides a model for how enzymatically catalyzed reactions can be quantitatively significant mechanisms for the reduction of iron and manganese in anaerobic environments.},
	issn = {0099-2240},
	author = {Lovley, D R and Phillips, E J}
}
