Garcia（iの頭は´）-Balboa,C., Pedrazza,A., Blazquez（aの頭に´）,M.L., Gonzalez（aの頭に´）,F., Munoz（nの頭に〜）,J.A. and Ballester,A.(2009): The role of iron bacteria on weathering and attenuation processes at acidic environments. Water Air Soil Pollut., 199, 203-217.

『酸性環境での風化と減衰過程に対する鉄バクテリアの役割』

『Abstract
The present research reproduces the chemical and microbiological reactions that occur naturally when a metal sulfide is discharged onto a natural soil, with special emphasis on iron cycle. The role of indigenous microbiota from an extremely acidic site on both weathering and attenuation processes related to the iron mobilization has been studied and the iron cycle has been reproduced at laboratory scale. In the first stage, the weathering phase, a residual sulfide mineral was bioleached using a mixed culture of iron-oxidizing bacteria isolated from the own substrate. The acid liquor obtained (pH 2), with a high metal concentration (160 mM in total iron), was filtered and neutralized. solids obtained from the two sources (from the weathering process and after the neutralization stage) were characterized by X-ray and scanning electron microscopy/energy dispersive X-ray spectroscopy, resulting ferric iron precipitates such as jarosites, goethites, and ferrihydrites with different crystalline properties. The contribution of ferric iron-reducing bacteria on the attenuation of high-content iron effluents was also studied. Mixed cultures of ferric iron-reducing bacteria, isolated from those acidic substrates, were active in reducing soluble ferric iron (60 mM in concentration), and a 66％ of bioreduction was reached after 15 days. Dissimilatory ferric iron reduction has been achieved with adapted cultures at pH values from 7 to 4.

Keywords: Weathering; Natural attenuation; Iron cycle; Iron oxidizers; Dissimilatory iron reducers』

1. Introduction
2. Materials and methods
　2.1. The model
　2.2. Samples
　2.3. Chemical and mineralogical characterization of samples
　2.4. Isolation and culture of bacteria
　　2.4.1. Ferrous iron oxidizers
　　2.4.2. Ferric iron reducers
　2.5. Weathering tests
　2.6. Dissimilatory Fe(III) reduction kinetic
3. Results and discussion
　3.1. Chemical and mineralogical characterization of the original samples
　3.2. Microbiology
　3.3. Weathering tests
　3.4. Kinetics of ferric iron-reducing bacteria
　3.5. Biogenic solids
4. Final remarks
Acknowledgments
References

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