title: Metagenomic Analysis Reveals Symbiotic Relationship among Bacteria in Microcystis-Dominated Community.
abstract: Microcystis bloom, a cyanobacterial mass occurrence often found in eutrophicated water bodies, is one of the most serious threats to freshwater ecosystems worldwide. In nature, Microcystis forms aggregates or colonies that contain heterotrophic bacteria. The Microcystis-bacteria colonies were persistent even when they were maintained in lab culture for a long period. The relationship between Microcystis and the associated bacteria was investigated by a metagenomic approach in this study. We developed a visualization-guided method of binning for genome assembly after total colony DNA sequencing. We found that the method was effective in grouping sequences and it did not require reference genome sequence. Individual genomes of the colony bacteria were obtained and they provided valuable insights into microbial community structures. Analysis of metabolic pathways based on these genomes revealed that while all heterotrophic bacteria were dependent upon Microcystis for carbon and energy, Vitamin B12 biosynthesis, which is required for growth by Microcystis, was accomplished in a cooperative fashion among the bacteria. Our analysis also suggests that individual bacteria in the colony community contributed a complete pathway for degradation of benzoate, which is inhibitory to the cyanobacterial growth, and its ecological implication for Microcystis bloom is discussed.
authors: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of SciencesWuhan, China; University of Chinese Academy of SciencesBeijing, China.
authors: Meili
authors: M
authors: Xie
authors: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of SciencesWuhan, China; University of Chinese Academy of SciencesBeijing, China.
authors: Minglei
authors: M
authors: Ren
authors: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of SciencesWuhan, China; University of Chinese Academy of SciencesBeijing, China.
authors: Chen
authors: C
authors: Yang
authors: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of SciencesWuhan, China; University of Chinese Academy of SciencesBeijing, China.
authors: Haisi
authors: H
authors: Yi
authors: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences Beijing, China.
authors: Zhe
authors: Z
authors: Li
authors: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences Wuhan, China.
authors: Tao
authors: T
authors: Li
authors: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of SciencesWuhan, China; College of Life Science, Peking UniversityBeijing, China.
authors: Jindong
authors: J
authors: Zhao
keywords: Microcystis; binning; bloom; metagenome; symbiosis