『Abstract
　Data from studies of dissimilatory bacterial (10⁸ cells mL^-1 of Shewanella putrefaciens strain CN32, pH 6.8) and ascorbate (10 mM, pH 3.0) reduction of two synthetic Fe(III) oxide coated sands and three natural Fe(III) oxide-bearing subsurface materials (all at ca. 10 mmol Fe(III) L^-1) were analyzed in relation to a generalized rate law for mineral dissolution (Jt/mo＝k'(m/mo)^γ, where Jt is the rate of dissolution and/or reduction at time t, mo is the initial mass of oxide, and m/mo is the unreduced or undissolved mineral fraction) in order to evaluate changes in the apparent reactivity of Fe(III) oxides during long-term biological vs. chemical reduction. The natural Fe(III) oxide assemblages demonstrated larger changes in reactivity (higher γ values in the generalized rate law) compared to the synthetic oxides during long-term abiotic reductive dissolution. No such relationship was evident in the bacterial reduction experiments, in which temporal changes in the apparent reactivity of the natural and synthetic oxides were far greater (5-10 fold higher γ values) than in the abiotic reduction experiments. Kinetic and thermodynamic considerations indicated that neither the abundance of electron donor (lactate) nor the accumulation of aqueous end-products of oxide reduction (Fe(II), acetate, dissolved inorganic carbon) are likely to have posed significant limitations on the long-term kinetics of oxide reduction. Rather, accumulation of biogenic Fe(II) on residual oxide surfaces appeared to play a dominant role in governing the long-term kinetics of bacterial crystalline Fe(III) oxide reduction. The experimental findings together with numerical simulations support a conceptual model of bacterial Fe(III) oxide reduction kinetics that differs fundamentally from established models of abiotic Fe(III) oxide reductive dissolution, and indicate that information on Fe(III) oxide reactivity gained through abiotic reductive dissolution techniques cannot be used to predict long-term patterns of reactivity toward enzymatic reduction at circumneutral pH.』

1. Introduction
2. Materials and methods
　2.1. Oxide phases and characterization
　2.2. Bacterial reduction experiments
　2.3. Ascorbate reduction experiments
　2.4. Thermodynamic calculations
　2.5. Numerical simulations
3. Kinetic framework and interpretation
4. Results and discussion
　4.1. Ascorbate reduction kinetics
　4.2. Bacterial reduction kinetics
　4.3. Thermodynamic analysis
　4.4. Conceptual model of long-term bacterial reduction kinetics
　　4.4.1. Surface-associated Fe(II) as a fundamental regulator
　　4.4.2. Numerical evaluation of the conceptual model
　4.5. Quantitative relationships between bacterial and chemical reduction kinetics
　　4.5.1. Temporal changes in reactivity
　　4.5.2. Initial rate correlations
5. Conclusions and implications for modeling natural soils and sediments
Acknowledgments
References
Appendix（Table A1〜A5）