论文
论文标题: An enzymatic mechanism for balancing the stoichiometry of nitrogen and phosphorus in a shallow Chinese eutrophic lake
作者: Xiao, Jian; Wang, Si-Yang; Zhou, Zi-Jun; Zhang, Yao; Song, Chun-Lei; Zhou, Yi-Yong; Cao, Xiu-Yun
出版刊物: SCIENCE OF THE TOTAL ENVIRONMENT
出版日期: JUL 15
出版年份: 2018
卷/期:
DOI: 10.1016/j.scitotenv.2018.02.297
论文摘要: The over-enrichment of lake waters with nitrogen (N) and phosphorus (P) has become a serious environmental problem, but modes of change in stoichiometry and enzymatic regeneration along trophic gradients are largely unknown. Seasonal variations in the kinetics of extracellular aminopeptidase (LAP) and alkaline phosphatase (AP), together with the composition of phytoplankton and concentrations of N and P, were examined from Jun 2013 to September 2014 in a Chinese shallow lake in which two basins had contrasting trophic states. The turbid basin had a significantly higher concentration of chlorophyll a and lower ratios of N to P. In parallel, the turnover time of organic N mediated by LAP (T-LAP) was significantly shorter, and its maximum velocity (V-max) was significantly higher compared to those in the clear basin. Considering data from both basins, there were linear decreases in N/P and the ratios between dissolved inorganic N and total N with an increasing trophic state index, coupled with a significantly positive relationship between N/P and LAPT. Additionally, with decreasing TN/TP, the Michaelis constant (K-m) of the AP increased linearly, reducing the efficiency of P regeneration. In contrast, the Km value of LAP decreased, and V-max increased, which enhanced Nmineralization by simultaneously increasing the reaction velocity and improving the affinity for substrate. Additionally, the K-m value of LAP was significantly related to that of AP and the ammonium concentration. Thus, substrate affinity acted as a key factor modifying the pathways of enzymatic degradation of organic N and P according to their stoichiometry in the water column. Phytoplankton composition was directly linked to LAPT. Overall, this study seemed to be the first to connect a stoichiometric shift of N and P with kinetics of extracellular enzymes responsible for their regeneration along trophic gradients, presenting an additional pathway to overcome nitrogen deficiency in eutrophic lakes. (C) 2018 Elsevier B.V. All rights reserved.
== 实验室与学会 ==
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  • 水产品种创制与高效养殖全国重点实验室
  • 中国科学院藻类生物学重点实验室
  • 农业部淡水养殖病害防治重点实验室
  • 武汉白暨豚保护基金会
  • 湖北省海洋湖沼学会
  • 中国动物学会原生动物学分会
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  • 中国水产学会鱼病学专业委员会
  • 中国鱼类学会
== 平台建设 ==
  • == 平台建设 ==
  • “一带一路”海域赤潮数据库
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  • 国家斑马鱼资源中心
  • 中国科学院淡水藻种库
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  • 中国科学院水生生物研究所分析测试中心
  • 中国科学院超级计算武汉分中心
  • 水生生物博物馆
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