Peretyazhko,T.S., Zachara,J.M., Kennedy,D.W., Fredrickson,J.K., Arey,B.W., McKinley,J.P., Wang,C.M., Dohnalkova,A.C. and Xia,Y.(2010): Ferrous phosphate surface precipitates resulting from the reduction of intragrain 6-line ferrihydrite by Shewanella oneidensis MR-1.Geochimica et Cosmochimica Acta, 74, 3751-3767.

『シェワネラ・オネイデンシス MR-1（バクテリア）による粒内6線フェリハイドライトの還元から生じる第一鉄リン酸塩の表面沈殿物』

『Abstract
　The reductive biotransformation of 6-line ferrihydrite located within porous silica (intragrain ferrihydrite) by Shewanella oneidensis MR-1 was investigated and compared to the behavior of 6-line ferrihydrite in suspension (free ferrihydrite). The effect of buffer type (PIPES and NaHCO3), phosphate (P), and an electron shuttle (AQDS) on the extent of reduction and formation of Fe(II) secondary phases was investigated under anoxic conditions. Electron microscopy and micro X-ray diffraction were applied to evaluate the morphology and mineralogy of the biogenic precipitates and to study the distribution of microorganisms on the surface of porous silica after bioreduction. Kinetic reduction experiments with free and intragrain ferrihydrite revealed contrasting behavior with respect to the buffer and presence of P. The overall amount of intragrain ferrihydrite reduction was less than that of free ferrihydrite [at 5 mmol L-1 Fe(III)T]. Reductive mineralization was not observed in the intragrain ferrihydrite incubations without P, and all biogenic Fe(II) concentrated in the aqueous phase. Irrespective of buffer and AQDS addition, rosettes of Fe(II) phosphate of approximate 20-39 μm size were observed on porous silica when P was present. The rosettes grew not only on the silica surface but also within it, forming a coherent spherical structure. These precipitates were well colonized by microorganisms and contained extracellular materials at the end of incubation. Microbial extracellular polymetric substances may have adsorbed Fe(II) promoting Fe(II) phosphate nucleation with subsequent crystal growth proceeding in different directions from a common center.』

1. Introduction
2. Materials and methods
　2.1. Bacterial strains and growth conditions
　2.2. Fe(III) (hydr)oxides
　2.3. Biomineralization experiments and analysis
　2.4. Electron microscopy
　2.5. Micro X-ray diffraction analysis
3. Results
　3.1. Microbial reduction of of free and intragrain ferrihydrite
　3.2. Biomineralization products
4. Discussion
5. Conclusions
Acknowledgments
Appendix A. Supplementary data
References

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