Abstract
A slowly moving, rod-shaped magnetotactic bacterium was found in relatively large numbers at and below the oxic-anoxic transition zone of a semianaerobic estuarine basin. Unlike all magnetotactic bacteria described to date, cells of this organism produce single-magnetic-domain particles of an iron oxide, magnetite (Fe(inf3)O(inf4)), and an iron sulfide, greigite (Fe(inf3)S(inf4)), within their magnetosomes. The crystals had different morphologies, being arrowhead or tooth shaped for the magnetite particles and roughly rectangular for the greigite particles, and were coorganized within the same chain(s) in the same cell with their long axes along the chain direction. Because the two crystal types have different crystallochemical characteristics, the findings presented here suggest that the formation of the crystal types is controlled by separate biomineralization processes and that the assembly of the magnetosome chain is controlled by a third ultrastructural process. In addition, our results show that in some magnetotactic bacteria, external environmental conditions such as redox and/or oxygen or hydrogen sulfide concentrations may affect the composition of the nonmetal part of the magnetosome mineral phase.
Full Text
The Full Text of this article is available as a PDF (1.0 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Balkwill D. L., Maratea D., Blakemore R. P. Ultrastructure of a magnetotactic spirillum. J Bacteriol. 1980 Mar;141(3):1399–1408. doi: 10.1128/jb.141.3.1399-1408.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bazylinski D. A., Garratt-Reed A. J., Frankel R. B. Electron microscopic studies of magnetosomes in magnetotactic bacteria. Microsc Res Tech. 1994 Apr 1;27(5):389–401. doi: 10.1002/jemt.1070270505. [DOI] [PubMed] [Google Scholar]
- Blakemore R. P., Maratea D., Wolfe R. S. Isolation and pure culture of a freshwater magnetic spirillum in chemically defined medium. J Bacteriol. 1979 Nov;140(2):720–729. doi: 10.1128/jb.140.2.720-729.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Delong E. F., Frankel R. B., Bazylinski D. A. Multiple evolutionary origins of magnetotaxis in bacteria. Science. 1993 Feb 5;259(5096):803–806. doi: 10.1126/science.259.5096.803. [DOI] [PubMed] [Google Scholar]
- Frankel R. B., Blakemore R. P., Wolfe R. S. Magnetite in freshwater magnetotactic bacteria. Science. 1979 Mar 30;203(4387):1355–1356. doi: 10.1126/science.203.4387.1355. [DOI] [PubMed] [Google Scholar]
- Frankel R. B. Magnetic guidance of organisms. Annu Rev Biophys Bioeng. 1984;13:85–103. doi: 10.1146/annurev.bb.13.060184.000505. [DOI] [PubMed] [Google Scholar]
- Gorby Y. A., Beveridge T. J., Blakemore R. P. Characterization of the bacterial magnetosome membrane. J Bacteriol. 1988 Feb;170(2):834–841. doi: 10.1128/jb.170.2.834-841.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moench T. T. Bilophococcus magnetotacticus gen. nov. sp. nov., a motile, magnetic coccus. Antonie Van Leeuwenhoek. 1988;54(6):483–496. doi: 10.1007/BF00588385. [DOI] [PubMed] [Google Scholar]
- Moench T. T., Konetzka W. A. A novel method for the isolation and study of a magnetotactic bacterium. Arch Microbiol. 1978 Nov 13;119(2):203–212. doi: 10.1007/BF00964274. [DOI] [PubMed] [Google Scholar]