title: Biological and chemical factors driving the temporal distribution of cyanobacteria and heterotrophic bacteria in a eutrophic lake (West Lake, China).
abstract: Physico-chemical parameters, hydrological conditions, and microbial interactions can affect the growth and persistence of cyanobacteria, but the interacting effects among these bloom-forming factors are still poorly known. This hampers our capacity to predict the occurrence of cyanobacterial bloom accurately. Here, we studied the relationship between temperature, N and P cycles, and the microbial community abundance and diversity at 0.5 m under the surface of West Lake (China) from January 21 to November 20, 2015, in order to better understand the key factors regulating temporal changes in the cyanobacterial community. Using high throughput sequencing of the 16S rRNA gene V3-V4 region, we studied the diversity and abundance of bacteria. In parallel, we measured physico-chemical parameters and followed the abundance of key genes involved in N fixation, denitrification, and nutrient uptake. Multivariate analyses suggest that P concentration and water temperature are the key factors controlling the outbreak of summer cyanobacterial bloom. RT-qPCR analyses of the bacterial community and measurements of the copy number of denitrification-related gene (nirK, nosZ, nirS) show that denitrification potential and denitrifying bacteria relative abundance (Pseudomonas and Bacillus) increased in concert with diazotrophic cyanobacterial genera (Anabaena, Nostoc, Aphanizomenon flos-aquae) and the common bloom-forming non-diazotrophic cyanobacterium genus Microcystis. The present study brings new insights on the complex interplay between physico-chemical parameters, heterotrophic bacterial community composition, nitrogen cycle, and cyanobacteria dominance in a eutrophic lake.
authors.affiliation: College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
authors.forename: Jiahui
authors.initials: J
authors.lastname: Xu
authors.affiliation: Quebec-Ocean and Takuvik Joint International Research Unit, Université Laval, Québec, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Lavoie
authors.affiliation: College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
authors.forename: Xiaoji
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
authors.forename: Guangfu
authors.initials: G
authors.lastname: Liu
authors.affiliation: College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
authors.forename: Liwei
authors.initials: L
authors.lastname: Sun
authors.affiliation: College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Fu
authors.affiliation: College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China. hfqian@zjut.edu.cn.|Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China. hfqian@zjut.edu.cn.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Qian
mesh_terms: D000458:Cyanobacteria / Q000502:physiology*; D004784:Environmental Monitoring; D060106:Lakes / Q000382:microbiology*; D014871:Water Microbiology
keywords: Cyanobacterial toxins; Denitrification; Microbial community; Microcystin; Nitrogen cycle; Phosphorus