不同水生植物腐解过程中有色可溶有机物(CDOM)的产生过程及微生物群落变化分析

通过对太湖的两种优势植物马来眼子菜(Potamogeton malaianus)和芦苇(Phragmites communis)进行室内腐解实验,利用紫外可见光谱和Illuminar高通量测序研究不同植物腐解过程中有色可溶有机物(CDOM)的产生情况及微生物群落变化。结果表明:马来眼子菜残体的去除率在2、10和30 d时均高于芦苇组。马来眼子菜组的溶解性有机碳(DOC)含量在第2天低于芦苇组,在第10天和第30天高于芦苇组。马来眼子菜组的CDOM相对浓度和其相对分子量在第2天高于芦苇组,在第10天和第30天低于芦苇组。初始水体中微生物分属34门、156纲,30天后,马来眼子菜和芦苇腐解液中的微生物多样性均降低了,分别分属23门和19门,以及95属和78属。两种植物在降解过程中,水体中降解难降解有机质类微生物逐渐占主要部分,如拟杆菌属(Bacteroides),密螺旋体属(Treponema),瘤胃微生物(Ruminococcaceae),此类微生物在芦苇降解组水体中的含量更多。

Analysis of the Production Process of Chromophoric Dissolved Organic Matter (CDOM) and the Change of Microbial Community in the Decomposition Process of Different Aquatic Plants

Abstract：In this study, two dominant plants of Taihu Lake, Potamogeton malaianus and Phragmites communis, were subjected to indoor decomposing experiments.UV-visible spectroscopy and Illuminar high-throughput sequencing were used to study the production of Chromophoric Dissolved Organic Matter (CDOM) and microbial community changes during the decomposition of different plants.The results showed that the removal rate of Potamogeton malaianus residues was higher than that of the Phragmites communis group on the second day, 10th day and 30th day.The Dissolved Organic Carbon (DOC) content of the Potamogeton malaianus group was lower than that of the Phragmites communis group on the second day and higher than the Phragmites communis group on the 10th and 30th day.The relative concentration of CDOM and its relative molecular mass of the Potamogeton malaianus group were higher than the Phragmites communis group on the second day and lower than the Phragmites communis group on the 10th and 30th day.The microbes in the initial water body belong to 34 phyla and 156 classes.Thirty days later, the microbial diversity in Potamogeton malaianus and Phragmites communis decomposing solution were reduced and belong to 23 and 19 phyla, and 95 and 78 genera, respectively.During the degradation process of the two plants, the degradation organic matter microorganisms in the water gradually occupied a major portion, such as Bacteroides, Treponema and Ruminococcaceae.These microorganisms are more abundant in the Phragmites communis decomposition water.