首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Respiratory interactions of soil bacteria with (semi)conductive iron‐oxide minerals
Authors:Souichiro Kato  Ryuhei Nakamura  Fumiyoshi Kai  Kazuya Watanabe  Kazuhito Hashimoto
Institution:1. Hashimoto Light Energy Conversion Project, ERATO, JST, 7‐3‐1 Hongo, Bunkyo‐ku, Tokyo 113‐8656, Japan.;2. Department of Applied Chemistry, The University of Tokyo, 7‐3‐1 Hongo, Bunkyo‐ku, Tokyo 113‐8656, Japan.;3. Research Center for Advanced Science and Technology, The University of Tokyo, 4‐6‐1 Komaba, Meguro‐ku, Tokyo 153‐8904, Japan.
Abstract:Pure‐culture studies have shown that dissimilatory metal‐reducing bacteria are able to utilize iron‐oxide nanoparticles as electron conduits for reducing distant terminal acceptors; however, the ecological relevance of such energy metabolism is poorly understood. Here, soil microbial communities were grown in electrochemical cells with acetate as the electron donor and electrodes (poised at 0.2 V versus Ag/AgCl) as the electron acceptors in the presence and absence of iron‐oxide nanoparticles, and respiratory current generation and community structures were analysed. Irrespective of the iron‐oxide species (hematite, magnetite or ferrihydrite), the supplementation with iron‐oxide minerals resulted in large increases (over 30‐fold) in current, while only a moderate increase (~10‐fold) was observed in the presence of soluble ferric/ferrous irons. During the current generation, insulative ferrihydrite was transformed into semiconductive goethite. Clone‐library analyses of 16S rRNA gene fragments PCR‐amplified from the soil microbial communities revealed that iron‐oxide supplementation facilitated the occurrence of Geobacter species affiliated with subsurface clades 1 and 2. We suggest that subsurface‐clade Geobacter species preferentially thrive in soil by utilizing (semi)conductive iron oxides for their respiration.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号