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Unexpected diversity in populations of the many‐celled magnetotactic prokaryote
Author(s) -
Simmons Sheri L.,
Edwards Katrina J.
Publication year - 2007
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2006.01129.x
Subject(s) - biology , prokaryote , magnetotactic bacteria , magnetosome , phylotype , population , evolutionary biology , ecology , 16s ribosomal rna , bacteria , paleontology , demography , sociology
Summary The many‐celled magnetotactic prokaryote (MMP) is an uncultivated, highly motile aggregate of 10–30 cells containing numerous chains of greigite (Fe 3 S 4 ) magnetosomes. It is unique to marine environments and is abundant in slightly sulfidic sediments of the Little Sippewissett salt marsh (Falmouth, MA). We sequenced 16s rDNA genes from a natural population of MMP and found five lineages separated by at least 5% sequence divergence. Fluorescent in situ hybridization probes for three of these lineages showed significant variation in their relative abundances across a seasonal cycle in marsh productivity. The MMP should therefore be considered a separate genus in the δ‐proteobacteria rather than a single species as previously thought. All cells in each aggregate express identical SSU rRNAs, suggesting that the aggregates are composed of a single MMP phylotype. This observation supports a model of the MMP as comprised of clonal cells which reproduce by binary fission of the aggregate.