Magnetite production and transformation in the methanogenic consortia from coastal riverine sediments
- 187 Downloads
Minerals that contain ferric iron, such as amorphous Fe(III) oxides (A), can inhibit methanogenesis by competitively accepting electrons. In contrast, ferric iron reduced products, such as magnetite (M), can function as electrical conductors to stimulate methanogenesis, however, the processes and effects of magnetite production and transformation in the methanogenic consortia are not yet known. Here we compare the effects on methanogenesis of amorphous Fe (III) oxides (A) and magnetite (M) with ethanol as the electron donor. RNA-based terminal restriction fragment length polymorphism with a clone library was used to analyse both bacterial and archaeal communities. Iron (III)-reducing bacteria including Geobacteraceae and methanogens such as Methanosarcina were enriched in iron oxide-supplemented enrichment cultures for two generations with ethanol as the electron donor. The enrichment cultures with A and non-Fe (N) dominated by the active bacteria belong to Veillonellaceae, and archaea belong to Methanoregulaceae and Methanobacteriaceae, Methanosarcinaceae (Methanosarcina mazei), respectively. While the enrichment cultures with M, dominated by the archaea belong to Methanosarcinaceae (Methanosarcina barkeri). The results also showed that methanogenesis was accelerated in the transferred cultures with ethanol as the electron donor during magnetite production from A reduction. Powder X-ray diffraction analysis indicated that magnetite was generated from microbial reduction of A and M was transformed into siderite and vivianite with ethanol as the electron donor. Our data showed the processes and effects of magnetite production and transformation in the methanogenic consortia, suggesting that significantly different effects of iron minerals on microbial methanogenesis in the iron-rich coastal riverine environment were present.
Keywordscoastal riverine sediments magnetite ferrous iron methane iron (III)-reducing bacteria methanogens
Unable to display preview. Download preview PDF.
- Bokulich, N.A., Bamforth, C.W., and Mills, D.A. 2012. A review of molecular methods for microbial community profiling of beer and wine. J. Am. Soc. Brew. Chem. 70, 150–162.Google Scholar
- Hori, T., Aoyagi, T., Itoh, H., Narihiro, T., Oikawa, A., Suzuki, K., Ogata, A., Friedrich, M.W., Conrad, R., and Kamagata, Y. 2015. Isolation of microorganisms involved in reduction of crystalline iron (III) oxides in natural environments. Front. Microbiol. 6, 386.CrossRefPubMedPubMedCentralGoogle Scholar
- Oren, A. 2014. The family Methanosarcinaceae, pp. 259–281. In Rosenberg, E., De Long, E.F., Lory, S., Stackebrandt, E., and Thomson, F. The Prokaryotes. Springer Berlin, Heidelberg, Germany.Google Scholar
- Schirmack, J., Mangelsdorf, K., Ganzert, L., Sand, W., Hillebrand-Voiculescu, A., and Wagner, D. 2014. Methanobacterium movilense sp. nov., a hydrogenotrophic, secondary-alcohol-utilizing methanogen from the anoxic sediment of a subsurface lake. Int. J. Syst. Evol. Microbiol. 64, 522–527.CrossRefPubMedGoogle Scholar