Dataset Information

Newly isolated but uncultivated magnetotactic bacterium of the phylum Nitrospirae from Beijing, China.

ABSTRACT: Magnetotactic bacteria (MTB) in the phylum Nitrospirae synthesize up to hundreds of intracellular bullet-shaped magnetite magnetosomes. In the present study, a watermelon-shaped magnetotactic bacterium (designated MWB-1) from Lake Beihai in Beijing, China, was characterized. This uncultivated microbe was identified as a member of the phylum Nitrospirae and represents a novel phylogenetic lineage with ?6% 16S rRNA gene sequence divergence from all currently described MTB. MWB-1 contained 200 to 300 intracellular bullet-shaped magnetite magnetosomes and showed a helical swimming trajectory under homogeneous magnetic fields; its magnetotactic velocity decreased with increasing field strength, and vice versa. A robust phylogenetic framework for MWB-1 and all currently known MTB in the phylum Nitrospirae was constructed utilizing maximum-likelihood and Bayesian algorithms, which yielded strong evidence that the Nitrospirae MTB could be divided into four well-supported groups. Considering its population densities in sediment and its high numbers of magnetosomes, MWB-1 was estimated to account for more than 10% of the natural remanent magnetization of the surface sediment. Taken together, the results of this study suggest that MTB in the phylum Nitrospirae are more diverse than previously realized and can make important contributions to the sedimentary magnetization in particular environments.

SUBMITTER: Lin W

PROVIDER: S-EPMC3264100 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Newly isolated but uncultivated magnetotactic bacterium of the phylum Nitrospirae from Beijing, China.

Lin Wei W Li Jinhua J Pan Yongxin Y

Applied and environmental microbiology 20111123 3

Magnetotactic bacteria (MTB) in the phylum Nitrospirae synthesize up to hundreds of intracellular bullet-shaped magnetite magnetosomes. In the present study, a watermelon-shaped magnetotactic bacterium (designated MWB-1) from Lake Beihai in Beijing, China, was characterized. This uncultivated microbe was identified as a member of the phylum Nitrospirae and represents a novel phylogenetic lineage with ≥6% 16S rRNA gene sequence divergence from all currently described MTB. MWB-1 contained 200 to 3 ...[more]

PMID: 22113917

Similar Datasets

Project description:Magnetotactic bacteria (MTB) are a group of microbes that biomineralize membrane-bound, nanosized magnetite (Fe3O4), and/or greigite (Fe3S4) crystals in intracellular magnetic organelle magnetosomes. MTB belonging to the Nitrospirae phylum can form up to several hundreds of Fe3O4 magnetosome crystals and dozens of sulfur globules in a single cell. These MTB are widespread in aquatic environments and sometimes account for a significant proportion of microbial biomass near the oxycline, linking these lineages to the key steps of global iron and sulfur cycling. Despite their ecological and biogeochemical importance, our understanding of the diversity and ecophysiology of magnetotactic Nitrospirae is still very limited because this group of MTB remains unculturable. Here, we identify and characterize two previously unknown MTB populations within the Nitrospirae phylum through a combination of 16S rRNA gene-based and genome-resolved metagenomic analyses. These two MTB populations represent distinct morphotypes (rod-shaped and coccoid, designated as XYR, and XYC, respectively), and both form more than 100 bullet-shaped magnetosomal crystals per cell. High-quality draft genomes of XYR and XYC have been reconstructed, and they represent a novel species and a novel genus, respectively, according to their average amino-acid identity values with respect to available genomes. Accordingly, the names Candidatus Magnetobacterium cryptolimnobacter and Candidatus Magnetomicrobium cryptolimnococcus for XYR and XYC, respectively, were proposed. Further comparative genomic analyses of XYR, XYC, and previously reported magnetotactic Nitrospirae reveal the general metabolic potential of this MTB group in distinct microenvironments, including CO2 fixation, dissimilatory sulfate reduction, sulfide oxidation, nitrogen fixation, or denitrification processes. A remarkably conserved magnetosome gene cluster has been identified across Nitrospirae MTB genomes, indicating its putative important adaptive roles in these bacteria. Taken together, the present study provides novel insights into the phylogenomic diversity and ecophysiology of this intriguing, yet poorly understood MTB group.

Dataset Information

Newly isolated but uncultivated magnetotactic bacterium of the phylum Nitrospirae from Beijing, China.

Publications

Newly isolated but uncultivated magnetotactic bacterium of the phylum Nitrospirae from Beijing, China.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets