title: Isolation of magnetotactic bacterium WM-1 from freshwater sediment and phylogenetic characterization.
abstract: The magnetotactic bacterium was isolated from freshwater sediment from North Lake of Wuhan. The isolate, designated WM-1, was Gram-negative, helical shaped, and studied by means of electron microscopy. The strain WM-1 was 0.2-0.4 microm in diameter and 3-4 microm in length. The DNA G + C content was found to be 65.7 mol%. Phylogenetic analysis of the 16S rDNA gene (Accession number DQ899734 in GeneBank) revealed that this isolate was a member ofalphasubdivision of the Proteobacteria. Strain WM-1 was closely related (97.7%) to Magnetospirillum sp. AMB-1. Randomly amplified polymorphic DNA analysis showed that these two strains were in fact different strains. Electron diffraction patterns of WM-1 magnetosomes indicated that the magnetosomes were composed of magnetite. The magnetosomes from WM-1 were cuboidal in shape as observed by electron microscopy. Statistical analysis of magnetite crystals from WM-1 showed narrow asymmetric size distribution. The average number of magnetosomes in each WM-1 bacterium was 8 +/- 3.4. The average length of magnetosomes in WM-1 was 54 +/- 12.3 nm and the average width is 43 +/- 10.9 nm. These data showed that the grains in WM-1 were single-domain crystals.
authors: College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
authors: Li
authors: L
authors: Wenbing
authors: Yu
authors: Y
authors: Longjiang
authors: Zhou
authors: Z
authors: Pengpeng
authors: Zhu
authors: Z
authors: Min
mesh_terms: D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005618:Fresh Water / Q000382:microbiology*; D019015:Geologic Sediments / Q000382:microbiology*; D042201:Magnetospirillum / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S