The shift of mutualistic relationships among algae, free-living and attached bacteria through different nutrient addition mode: a mesocosm study
The shift of mutualistic relationships among algae, free-living and attached bacteria through different nutrient addition mode: a mesocosm study
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通过不同的营养添加模式改变藻类、自由生活和附着细菌之间的互利关系：一项中生态研究
DOI：
10.1080/02705060.2020.1858984
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发表时间：
2020-01-01
影响因子：
1.3
通讯作者：
Song, Chunlei
中科院分区：
文献类型：
--
作者：
Cao, Xiuyun;Li, Hui;Song, Chunlei
摘要 在实验环境中，设计了过量磷（P）、过量碳（C）和过量氮（N）与P为16:1的3种营养添加处理，研究了藻类、自生菌和附着菌之间互利养分关系的转变以及对藻类生长的影响。在所有处理中藻类群落组成没有发生很大变化。在过量的P和N:P为16:1的处理中，藻类与其附着细菌之间的互利共生得到证实，藻类溶解的有机养分明显较高，附着细菌产生的胞外酶活性高丰度和产量。有趣的是，与过量磷处理相比，这种互利共生在N：P为16：1的处理中更加明显，并导致更强的生态功能，表现为更高的叶绿素a含量，表明化学计量平衡养分添加的重要性。相反，过多的有机碳输入导致藻类与自由生存的细菌之间的营养竞争，由于后者生物量的增长和对无机营养物质的过度吸收，最终限制了藻类的生长。我们的结果表明，藻类、自由生活和附着细菌之间的互利关系可以通过营养平衡（N：P比率）和溶解的有机碳有效性来改变。图解摘要
Abstract The shift of mutualistic nutrient relationship among algae, free-living and attached bacteria as well as the effects on algal growth were conducted in experimental mesocosm in which three nutrient addition treatments, including excessive phosphorus (P), excessive carbon (C) and nitrogen (N) to P as 16:1, were designed. The algal community composition did not change greatly in all treatments. The mutualism between algae and its attached bacteria was confirmed in treatments with excessive P and N:P as 16:1, in terms of the significantly higher dissolved organic nutrients derived from algae, extracellular enzyme activities produced by attached bacteria with high abundance and production. Interestingly, compared to treatment with excessive P, this mutualism was even more pronounced in treatment with N:P as 16:1, and resulted in stronger ecological function expressed as higher chlorophyll a content, indicating the importance of nutrient addition with stoichiometric equilibrium. On the contrary, excessive organic C input led to the nutrients competition between algae and free-living bacteria due to the latter’s growth in biomass and luxury uptake of inorganic nutrients, which finally limited algal growth. Our results indicated that mutualistic relationship among algae, free-living and attached bacteria could be shifted by nutrient equilibrium (N:P ratio) and dissolved organic C availability. Graphical Abstract