Iron transformations induced by an acid-tolerant Desulfosporosinus species.
The mineralogical transformations of Fe phases induced by an acid-tolerant, Fe(III)- and sulfate-reducing bacterium, Desulfosporosinus sp. strain GBSRB4.2 were evaluated under geochemical conditions associated with acid mine drainage-impacted systems (i.e., low pH and high Fe concentrations). X-ray powder diffractometry coupled with magnetic analysis by first-order reversal curve diagrams were used to evaluate mineral phases produced by GBSRB4.2 in media containing different ratios of Fe(II) and Fe(III). In medium containing Fe predominately in the +II oxidation state, ferrimagnetic, single-domain greigite (Fe₃S₄) was formed, but the addition of Fe(III) inhibited greigite formation. In media that contained abundant Fe(III) [as schwertmannite; Fe₈O₈(OH)₆SO₄ · nH₂O], the activities of strain GBSRB4.2 enhanced the transformation of schwertmannite to goethite (α-FeOOH), due to the increased pH and Fe(II) concentrations that resulted from the activities of GBSRB4.2.
Department of Geology and Environmental Science, The University of Akron, Akron, Ohio, USA.
Doug
D
Bertel
John
J
Peck
Thomas J
TJ
Quick
John M
JM
Senko
D001673:Biodegradation, Environmental; D001711:Biotransformation; D003032:Coal Mining; D005290:Ferric Compounds / Q000378:metabolism*; D005296:Ferrous Compounds / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D058085:Iron Compounds / Q000378:metabolism; D008903:Minerals / Q000378:metabolism; D010459:Peptococcaceae / Q000254:growth & development / Q000378:metabolism*; D033362:Powder Diffraction; D013440:Sulfides / Q000378:metabolism; D014961:X-Ray Diffraction
D005290:Ferric Compounds; D005296:Ferrous Compounds; D058085:Iron Compounds; D008903:Minerals; D013440:Sulfides; C111959:greigite; C511969:schwertmannite; C094886:goethite; C011342:pyrite; D007501:Iron