Metagenomics analysis of microbial communities grown in constructed wetland-microbial fuel cell system treating sewage wastewater

Sewage wastewater poses a significant environmental threat, necessitating adequate treatment before disposal. This study investigates the microbial community structure and functional analysis involved in the treatment and detoxification of sewage wastewater using a constructed wetland integrated with microbial fuel cell system. High-throughput Illumina sequencing was employed to analyze microbial diversity. Sludge samples were collected from the root zone of Canna indica and the cathode samples for metagenomic profiling. Rarefaction curves and alpha diversity analysis demonstrated a higher abundance of microbial diversity in rhizospheric sludge sample comrated to cathodic sample. Taxonomic classification revealed Proteobacteria as the dominant phylum in the developed system. At the genus level, the sludge samples were dominated by uncultured bacterial genera. Notably, a substantial portion of the microbial community could not be identified at the genus and species levels, categorized as Unidentified. Functional profiling revealed the presence of genes associated with degradative pathways in sewage wastewater. These findings suggest that the rhizosphere of Canna indica supports a greater bacterial diversity than the cathode samples, contributing to the enhanced treatment efficiency of the developed system.

污水（sewage wastewater）会对环境造成严重威胁，因此在排放前需进行妥善处理。本研究针对集成微生物燃料电池（microbial fuel cell, MFC）的人工湿地系统处理污水并实现脱毒的过程，开展微生物群落结构与功能解析研究。本研究采用高通量Illumina测序技术分析微生物多样性，从美人蕉（Canna indica）根际区域采集污泥样本，并采集阴极样本用于宏基因组分析。稀释曲线与α多样性分析结果显示，根际污泥样本的微生物多样性丰度显著高于阴极样本。分类学鉴定结果表明，在该构建系统中，变形菌门（Proteobacteria）为优势菌门。在属水平上，污泥样本的优势类群为未培养细菌属。值得注意的是，有相当比例的微生物群落无法在属和种水平上被鉴定，被归类为未鉴定类群（Unidentified）。功能注释分析显示，污水降解相关通路的功能基因在该系统中广泛存在。上述研究结果表明，美人蕉根际区域的细菌多样性显著高于阴极样本，这有助于提升该构建系统的污水处理效率。