title: Comment on "Early Archaean microorganisms preferred elemental sulfur, not sulfate".
abstract: Philippot et al. (Reports, 14 September 2007, p. 1534) interpreted multiple-sulfur isotopic compositions of approximately 3.5-billion-year-old marine sulfide deposits as evidence that early Archaean microorganisms were not sulfate reducers but instead metabolized elemental sulfur. However, their data can be better explained by a scenario involving poor mixing of photochemical and surface sulfide sources.
authors.affiliation: Department of Geology and Geophysics, Louisiana State University, E235 Howe-Russell Geoscience Complex, Baton Rouge, LA 70803, USA. bao@lsu.edu
authors.forename: Huiming
authors.initials: H
authors.lastname: Bao
authors.forename: Tao
authors.initials: T
authors.lastname: Sun
authors.forename: Issaku
authors.initials: I
authors.lastname: Kohl
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Peng
mesh_terms: D019015:Geologic Sediments / Q000737:chemistry; D007501:Iron / Q000032:analysis; D010084:Oxidation-Reduction; D010777:Photochemistry; D013431:Sulfates / Q000378:metabolism*; D013440:Sulfides / Q000032:analysis; D013455:Sulfur / Q000737:chemistry / Q000378:metabolism*; D013460:Sulfur Isotopes / Q000032:analysis; D016999:Sulfur-Reducing Bacteria / Q000378:metabolism*
chemical_list: D013431:Sulfates; D013440:Sulfides; D013460:Sulfur Isotopes; C011342:pyrite; D013455:Sulfur; D007501:Iron