title: Influence of phosphorus availability on the community structure and physiology of cultured biofilms.
abstract: Biofilms have important effects on nutrient cycling in aquatic ecosystems. However, publications about the community structure and functions under laboratory conditions are rare. This study focused on the developmental and physiological properties of cultured biofilms under various phosphorus concentrations performed in a closely controlled continuous flow incubator. The results showed that the biomass (Chl a) and photosynthesis of algae were inhibited under P-limitation conditions, while the phosphatase activity and P assimilation rate were promoted. The algal community structure of biofilms was more likely related to the colonization stage than with the phosphorus availability. Cyanobacteria were more competitive than other algae in biofilms, particularly when cultured under low P levels. A dominance shift occurred from non-filamentous algae in the early stage to filamentous algae in the mid and late stages under P concentrations of 0.01, 0.1 and 0.6 mg/L. However, the total N content, dry weight biomass and bacterial community structure of biofilms were unaffected by phosphorus availability. This may be attributed to the low respiration rate, high accumulation of extracellular polymeric substances and high alkaline phosphatase activity in biofilms when phosphorus availability was low. The bacterial community structure differed over time, while there was little difference between the four treatments, which indicated that it was mainly affected by the colonization stage of the biofilms rather than the phosphorus availability. Altogether, these results suggested that the development of biofilms was influenced by the phosphorus availability and/or the colonization stage and hence determined the role that biofilms play in the overlying water.
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. Electronic address: lishuangs2010@163.com.
authors.forename: Shuangshuang
authors.initials: S
authors.lastname: Li
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Qin
authors.affiliation: Department of Resource and Environmental Engineering, Henan Institute of Engineering, Zhengzhou 451191, China.
authors.forename: Yinxia
authors.initials: Y
authors.lastname: Li
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.
authors.forename: Chengrong
authors.initials: C
authors.lastname: Peng
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. Electronic address: lidh@ihb.ac.cn.
authors.forename: Dunhai
authors.initials: D
authors.lastname: Li
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D000458:Cyanobacteria; D017753:Ecosystem; D010758:Phosphorus / Q000032:analysis* / Q000378:metabolism; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus
keywords: Chlorophyll fluorescence; Cultured biofilms; Microbial community structure; Phosphatase activity; Phosphorus availability