| 摘要: |
| 解磷菌(phosphate-solubilizing microorganisms,PSM)在沉积物磷释放的过程中发挥着重要的作用,但在湖泛发生过程中,沉积物中PSM对磷释放的影响以及PSM对湖泛的适应机制尚不清楚。本研究分别在湖泛与非湖泛期从太湖收集了上覆水和沉积物样品,测定了样品中主要理化因子,应用Illumina高通量测序技术分析了湖泛前后沉积物中PSM种群结构差异。研究结果表明,相较于非湖泛期,湖泛期上覆水中总磷(TP)和磷酸根(PO43)-浓度提高了10倍以上。湖泛期间沉积物中PSM的相对丰度约是非湖泛期的7倍。在湖泛期间,沉积物中的PSM以不动杆菌属(Acinetobacter),鞘氨醇杆菌(Novosphingobium)和黄杆菌(Flavobacterium)为主,非湖泛期沉积物中PSM分布较少。相关性分析结果表明,主相关性分析结果表明,不同的PSM对各种磷形态的释放影响存在差异,主要PSM与有机磷(Org-P)、铁结合态磷(BD-P)和钙结合态磷(Ca-P)的相关性系数均小于-0.627。微生物网络分析表明,湖泛期PSM的正相关邻节点主要为反硝化细菌和发酵菌,负相关邻节点主要是铁还原菌和硫酸盐还原菌,这说明PSM在磷释放过程中倾向于和反硝化细菌及参与有机质代谢的发酵细菌进行协作,在与铁还原菌和硫还原菌的竞争中处于生态优势位,而沉积物中内源磷的释放是PSM与多种微生物共同作用的结果。综上所述,PSM能够调整群落结构及其相关细菌的相互作用来应对湖泛的发生,本研究结果有助于进一步认识PSM对沉积物磷释放及其对湖泊环境变化的适应过程。 |
| 关键词: 湖泛 沉积物 解磷菌 磷形态 微生物群落 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目(NO. 41 807452) |
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| Black blooms-induced adaptive responses of phosphate-solubilizing bacteria in a shallow freshwater lake and their impact on phosphorus release from sediments |
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Zhou Shiwei1, Jiao Yiying2, Zhu Zhijie1, Xue Simin1, Li Ruizhe1, Dai Yudai1, Chen Mo1
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1.Key Laboratory of regional development and environmental response of Hubei Provincial,College of resources and environment,Hubei University;2.Key Laboratory of river and lake ecological restoration and algae utilization of Hubei Provincial,College of civil architecture and environment,Hubei University of Technology
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| Abstract: |
| Phosphate-solubilizing microorganisms (PSM) play an important role in the process of sediment phosphorus release. However, the effect of PSM on phosphorus release in sediments and the adaptation mechanism of PSM to black bloom are still unclear. This study collected surface water and sediment samples from Lake Taihu during black and non-black bloom periods, and determined the major physicochemical factors in the samples. The Illumina high-throughput sequencing technology was applied to analyze the differences in the population structure of PSM in sediment during black and non-black bloom periods. The results indicated that the concentrations of TP and PO43- in the surface water during the black bloom period were more than 10 times higher than those during the non-black bloom period. The relative abundance of PSM in the sediments during the black bloom period was about 7 times that of the non-black bloom period. During the black bloom period, PSM in sediments was dominated by Acinetobacter, Novosphingobium and Flavobacterium, and PSM was less distributed in non-black bloom sediments. The correlation analysis results indicate that different PSM genera have varying effects on the release of different phosphorus fractions. The correlation coefficients between the main PSM and organic phosphorus (Org-P), iron-bound phosphorus (BD-P) and calcium-bound phosphorus (Ca-P) were less than -0.627. The microbial network analysis showed that the positive correlation nodes of PSM in the black bloom period were mainly denitrifying bacteria and fermenting bacteria, and the negative correlation nodes were mainly iron-reducing bacteria and sulfate-reducing bacteria. This indicates that PSM tends to cooperate with denitrifying bacteria and fermentation bacteria involved in organic matter metabolism in the process of phosphorus release, and is in an ecological dominant position in the competition with iron-reducing bacteria and sulfur-reducing bacteria. The release of endogenous phosphorus in sediments is the result of the interaction between PSM and various microorganisms. In summary, PSM can adjust the community structure and its interaction with related bacteria to cope with the occurrence of black bloom, These results extend our knowledge on the importance of PSM during black blooms and the adaptation of PSM to environmental changes in freshwater lakes. |
| Key words: lake eutrophication sediment phosphorus-degrading bacteria phosphorus fractions microbial community |
