Characterization of uncultivated magnetotactic bacteria from the sediments of Yuehu Lake, China

• Published in: Acta oceanologica Sinica 2017-02, Vol.36 (2), p.94-104
• Main Authors: Du, Haijian, Zhang, Rui, Zhang, Wenyan, Xu, Cong, Chen, Yiran, Pan, Hongmiao, Zhou, Ke, Wu, Long-fei, Xiao, Tian
• Format: Article
• Language: English
• Subjects: Bacteria; Biochemistry, Molecular Biology; Cellular Biology; Climatology; Crystals; Cytology; DNA sequencing; Earth and Environmental Science; Earth Sciences; Ecology; Electron microscopy; Engineering Fluid Dynamics; Environmental Chemistry; Environmental Sciences; Flagella; Freshwater; Gene sequencing; Genetics; Germfree; High resolution electron microscopy; Iron oxides; Lakes; Life Sciences; Magnetotaxis; Marine; Marine & Freshwater Sciences; Microbial activity; Microorganisms; Oceanography; rRNA 16S; Sediment; Sediments; Sequence analysis; Sequencing; Transmission electron microscopy; 中国; 基因序列分析; 月湖; 沉积物; 特性; 细胞形态; 趋磁细菌; 透射电子显微镜
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-017-0980-8

Marine magnetotactic bacteria were collected from the intertidal sediments of Yuehu Lake（China）, where their abundance reached 103–104 ind./cm3. Diverse morphotypes of magnetotactic bacteria were observed, including cocci and oval, vibrio-, spirillum-, rod-, elliptical-, handle- and bar-shaped forms. The magnetococci were the most abundant, and had flagella arranged in parallel within a bundle. The majority of magnetosomes were arranged in one, two or multiple chains, although irregular arrangements were also evident. All the results of high-resolution transmission electron microscopy（HRTEM） analysis show that magnetosome crystals were composed of Fe3O4, and their morphology was specific to particular cell morphotypes. By the 16 S r RNA gene sequence analysis, we found fourteen operational taxonomic units（OTUs） which were related to magnetotactic bacteria. Among these, thirteen belonged to the Alphaproteobacteria and one to the Gammaproteobacteria.Compared with known axenic and uncultured marine magnetotactic bacteria, the 16 S r RNA gene sequences of most magnetotactic bacteria collected from the Yuehu Lake exhibited sequence identities ranging from 90.1% to96.2%（〈97%）. The results indicate that microbial communities containing previously unidentified magnetotactic bacteria occur in the Yuehu Lake.