| 摘要: |
| 在气候变暖和人类活动增加的双重压力下，湖泊富营养化和藻华爆发导致大量藻类溶解性有机物（algal dissolved organic matter，ADOM）产生，其转化过程是湖泊碳循环研究的重点。为探究湖泊中光化学转化对ADOM微生物转化的影响，本研究以富营养化湖泊（太湖）中的ADOM为对象，进行18天的微生物培养和先自然光照后微生物培养实验。通过紫外-可见光谱法、三维荧光光谱-平行因子分析法、傅里叶变换-离子回旋共振质谱法比较两处理组中ADOM的有色DOM，荧光DOM和分子转化差异，以及通过16S rRNA测序技术探究微生物群落变化。结果表明，光-微生物处理组DOC的降解速率明显低于微生物处理组 （0.28 d-1 vs. 0.75 d-1）。转化过程中荧光组分和分子的变化显示：光化学过程对类蛋白质/多肽类分子的转化减少了微生物转化的底物，且光化学生成的分子仅有近一半能够被后续的微生物过程利用。微生物处理组细菌多样性显著高于光-微处理组；一些菌属的丰度与DOM组分显著相关，表明光化学过程对ADOM组成的改变是影响微生物群落结构的重要原因。研究揭示了自然光照对ADOM微生物转化的抑制机制，有助于全面理解富营养化湖泊的碳循环过程。 |
| 关键词: 藻源性有机质 光化学转化 微生物转化 分子组成 细菌群落结构 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
|
| Effect Mechanism of Solar Photodegradation on Microbial Transformation of Algal Dissolved Organic Matter |
|
Kang RuYun,An ShiLin,Huang XiuLin,Li XueYan,Du YingXun
|
|
Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences
|
| Abstract: |
| Under the dual stress of climate warming and increased human activities, lake eutrophication and the algal bloom have expanded in the world, releasing large amounts of algal dissolved organic matter (ADOM), and its transformation process is the focus of lake carbon cycle research. To reveal the role of photochemical transformation on the microbial transformation of ADOM in lakes, we compared ADOM transformation in microbial treatment and natural light-microbial treatment. The differences in the transformation of ADOM in the two treatments were compared in detail through ultraviolet-visible spectroscopy, three-dimensional fluorescence spectroscopy-parallel factor analysis and Fourier transform-ion cyclotron resonance mass spectrometry. In addition, microbial community was explored by 16S rRNA sequencing. The results showed that the solar irradiation greatly inhibited the DOC removal rate by microbial treatment. The changes of the fluorescent treatment. The changes of the fluorescent components and molecular composition demonstrated that a significant competition for the protein-like components and peptide-like formulas between photochemical and microbial processes. In addition, only part of the photochemically generated molecules could be utilized by subsequent microbial processes. The bacterial diversity in microbial treatment was significantly higher than that of the light-microbial treatment. The significant correlation between the abundance of some bacteria taxa and DOM components suggested that the alteration of ADOM composition by photochemical transformation had a key influence on the structure of the microbial community. Our study revealed the inhibitory mechanism of natural light on the microbial transformation of ADOM, which is important to understand the carbon cycle process of eutrophic lakes. |
| Key words: Algal organic matter Photochemistry Microbial transformation Molecular composition Bacterial community |
