title: Characterization of a homogeneous taxonomic group of marine magnetotactic cocci within a low tide zone in the China Sea.
abstract: Magnetotactic bacteria are a heterologous group of motile prokaryotes, ubiquitous in aquatic habitats and cosmopolitan in distribution. Here, we studied the diversity of magnetotactic bacteria in a seawater pond within an intertidal zone at Huiquan Bay in the China Sea. The pond is composed of a permanently submerged part and a low tide subregion. The magnetotactic bacteria collected from the permanently submerged part display diversity in morphology and taxonomy. In contrast, we found a virtually homogenous population of ovoid-coccoid magnetotactic bacteria in the low tide subregion of the pond. They were bilophotrichously flagellated and exhibited polar magnetotactic behaviour. Almost all cells contained two chains of magnetosomes composed of magnetite crystals. Intriguingly, the combination of restriction fragment length polymorphism analysis (RFLP) and sequencing of cloned 16S rDNA genes from the low tide subregion samples as well as fluorescence in situ hybridization (FISH) revealed the presence of a homogenous population. Moreover, phylogenetic analysis indicated that the Qingdao Huiquan low tide magnetotactic bacteria belong to a new genus affiliated with the alpha-subclass of Proteobacteria. This finding suggests the adaptation of the magnetotactic bacterial population to the marine tide.
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China.
authors.forename: Hongmiao
authors.initials: H
authors.lastname: Pan
authors.forename: Kailing
authors.initials: K
authors.lastname: Zhu
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.forename: Kui
authors.initials: K
authors.lastname: Yu-Zhang
authors.forename: Christopher
authors.initials: C
authors.lastname: Lefèvre
authors.forename: Sue
authors.initials: S
authors.lastname: Xing
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Sanjun
authors.initials: S
authors.lastname: Zhao
authors.forename: Tian
authors.initials: T
authors.lastname: Xiao
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Wu
mesh_terms: D020561:Alphaproteobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D002681:China; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal; D019015:Geologic Sediments / Q000382:microbiology*; D017404:In Situ Hybridization, Fluorescence; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D015388:Organelles / Q000648:ultrastructure; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S