基于高通量测序的SBR反应器丝状膨胀污泥菌群分析

为探究丝状污泥膨胀及控制过程中细菌菌群和真菌菌群的变化规律,采用一套11 L的SBR反应器,接种某城市污水处理厂膨胀污泥,以乙酸钠为碳源进行人工配水,对膨胀污泥进行399 d的培养实验,采用高通量测序技术对污泥样本进行菌群多样性分析.结果表明,接种污泥菌群多样性比较丰富,经培养至污泥高度膨胀后,菌群多样性降低,污泥沉降性能恢复正常后,菌群多样性又逐渐增加.细菌中的腐螺旋菌属(Saprospiraceae_norank)、丛毛单胞菌属(Comamonadaceae_unclassified)和四球菌属(Tetrasphaera)相对丰度分别为13.37%、10.54%和8.59%,是接种污泥的主要细菌属.经过培养,膨胀污泥菌群发生变化,接种污泥中细菌相对丰度仅为0.01%的丝硫菌属(Thiothrix)增加至56.95%~60.14%,真菌中相对丰度为19.60%的丝孢菌属(Trichosporon)增加至94.82%.污泥膨胀得到控制后,污泥中丝硫菌属(Thiothrix)相对丰度减少至0.01%,丝孢菌属(Trichosporon)相对丰度减少至2.32%.丝硫菌属(Thiothrix)和丝孢菌属(Trichosporon)过多不利于污泥沉降.

Filamentous Sludge Microbial Community of a SBR Reactor Based on High-throughput Sequencing

Samples were collected from a sequencing batch reactor (SBR) to characterize the similarities and differences in microbial community composition in samples using Illumina high-throughput sequencing. The main objective of this study was to characterize changes in microbial community composition during filamentous sludge bulking and control processes. The SBR working volume was 11 L, and the reactors were operated for 399 days in total. High-throughput sequencing results indicated that rich diversity existed in the microbial communities of the seeding sludge. Generally, during sludge bulking, microbial composition decreased, and after the sludge was remediated, the diversity gradually increased. The dominant bacteria in the seeding sludge were Saprospiraceae_norank, Comamonadaceae_unclassified, and Tetrasphaera, comprising 13.37%, 10.54%, and 8.59% of the community, respectively. After culturing using sodium acetate as the sole carbon source, Thiothrix and Trichosporon increased significantly from the seeding to the bulking sludge, with ranges from 0.1% to 60.14% and from 19.60% to 94.82%, respectively. After the sludge bulking was controlled, the relative abundances of Thiothrix and Trichosporon were 0.1% and 2.32%, respectively. Therefore, we postulate that increases in filamentous Thiothrix and Trichosporon were the main cause for the sludge bulking.