학술논문
水体中蓝藻水华分解产甲烷动态过程研究 / Dissolved methane dynamics during the degradation of organic matter derived from cyanobacterial bloom
Document Type
Academic Journal
Author
Source
中国环境科学. 37(2):702-710
Subject
Language
Chinese
ISSN
1000-6923
Abstract
在巢湖开展蓝藻分解的原位围隔实验，实验期间测定围隔中层水体溶解性甲烷浓度和主要理化因子，通过定量PCR的方法测定产甲烷菌mcrA基因拷贝数以及细菌和古菌16S rRNA基因拷贝数随时间的变化情况.结果显示：随着蓝藻有机质分解，水体产甲烷菌数量逐渐增加，溶解性甲烷浓度最高达到2.94mg/L；产甲烷菌mcrA基因拷贝数与甲烷浓度具有显著的正相关关系；同时还发现水体中的亚铁离子(Fe2+)含量与产甲烷菌的数量具有显著的正相关关系.上述结果支持蓝藻水华爆发导致水体也成为甲烷生物合成热点区域的观点.本研究获得的结果有助于进一步分析不同产甲烷热点区域(水体和沉积物)对湖泊甲烷总体释放量的贡献情况.
In shallow eutrophic lakes, methane production during the decomposition of organic matter derived from cyanobacterial blooms and associated factors for the whole process in the water column remain poorly understood. In this work, in situ mesocosms experiment in Lake Chaohu were carried out to stimulate the Cyanobacteria anaerobic decomposition. During the process, dissolved methane concentration and the main environmental factors were measured at the water bottom. Quantitative real-time PCR method was applied to analyze the abundance ofmcrA gene as well as the bacterial and archaeal 16S rRNA genes in each sample. Results showed that with the biomass decomposition, the amount of methanogens increased gradually in accordance with the accumulation of dissolved methane in the water column (maximum concentration 2.94mg/L). A significantly positive correlation was detected betweenmcrA gene abundance and the dissolved methane concentration. Furthermore, there was also a significantly positive correlation between ferrous ions (Fe2+) concentration and the methanogenmcrA abundance. Our results support for the notion that water column can be a hot spot for the biosynthesis of methane due to the outbreak of cyanobacterial bloom. This study helps to compare the relative contribution of methane production between water column and surface sediments during the cyanobacterial blooms degradation.
In shallow eutrophic lakes, methane production during the decomposition of organic matter derived from cyanobacterial blooms and associated factors for the whole process in the water column remain poorly understood. In this work, in situ mesocosms experiment in Lake Chaohu were carried out to stimulate the Cyanobacteria anaerobic decomposition. During the process, dissolved methane concentration and the main environmental factors were measured at the water bottom. Quantitative real-time PCR method was applied to analyze the abundance ofmcrA gene as well as the bacterial and archaeal 16S rRNA genes in each sample. Results showed that with the biomass decomposition, the amount of methanogens increased gradually in accordance with the accumulation of dissolved methane in the water column (maximum concentration 2.94mg/L). A significantly positive correlation was detected betweenmcrA gene abundance and the dissolved methane concentration. Furthermore, there was also a significantly positive correlation between ferrous ions (Fe2+) concentration and the methanogenmcrA abundance. Our results support for the notion that water column can be a hot spot for the biosynthesis of methane due to the outbreak of cyanobacterial bloom. This study helps to compare the relative contribution of methane production between water column and surface sediments during the cyanobacterial blooms degradation.