title: Microbial Succession and Nitrogen Cycling in Cultured Biofilms as Affected by the Inorganic Nitrogen Availability.
abstract: Biofilms play important roles in nutrients and energy cycling in aquatic ecosystems. We hypothesized that as eutrophication could change phytoplankton community and decrease phytoplankton diversity, ambient inorganic nitrogen level will affect the microbial community and diversity of biofilms and the roles of biofilms in nutrient cycling. Biofilms were cultured using a flow incubator either with replete inorganic nitrogen (N-rep) or without exogenous inorganic nitrogen supply (N-def). The results showed that the biomass and nitrogen and phosphorous accumulation of biofilms were limited by N deficiency; however, as expected, the N-def biofilms had significantly higher microbial diversity than that of N-rep biofilms. The microbial community of biofilms shifted in composition and abundance in response to ambient inorganic nitrogen level. For example, as compared between the N-def and the N-rep biofilms, the former consisted of more diazotrophs, while the latter consisted of more denitrifying bacteria. As a result of the shift of the functional microbial community, the N concentration of N-rep medium kept decreasing, while that of N-def medium showed an increasing trend in the late stage. This indicates that biofilms can serve as the source or the sink of nitrogen in aquatic ecosystems, and it depends on the inorganic nitrogen availability.
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Shuangshuang
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
authors.forename: Chengrong
authors.initials: C
authors.lastname: Peng
authors.affiliation: University of Chinese Academy of Sciences, Beijing, 100049, China.|Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Jiaoli
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China. lidh@ihb.ac.cn.
authors.forename: Dunhai
authors.initials: D
authors.lastname: Li
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D018533:Biomass; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D017753:Ecosystem; D005068:Eutrophication; D064307:Microbiota; D009584:Nitrogen / Q000737:chemistry; D058458:Nitrogen Cycle / Q000502:physiology*; D010839:Phytoplankton / Q000145:classification* / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014871:Water Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S; D002734:Chlorophyll; D009584:Nitrogen; D000077194:Chlorophyll A
keywords: Cultured biofilms; Microbial community; Microbial diversity; Microbial succession; Nitrogen availability; Nitrogen cycling