生物除磷系统不同阶段性能及微生物群落分析

Performance and microbial community structure analysis of biological phosphorus removal system in different periods

为探讨工艺运行与微生物群落的关系,在厌氧/好氧SBR反应器中考察生物除磷系统的启动期、稳定期和恶化期的性能,并利用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术研究该系统各阶段功能微生物群落结构特征.启动期历时26d,包括适应期和上升期两个阶段,磷的去除率从40%以下提高到80%,之后进入稳定期,磷去除率维持在80%以上.稳定期的功能微生物为Tetrasphaera elongate,Gemmatimonas aurantiaca和Uncultured γ-proteobacterium.稳定运行80d后进入恶化期,磷去除率降到70%以下.恶化期和稳定期的微生物群落结构差别很大,功能微生物Uncultured γ-proteobacterium被淘汰,竞争菌Candidatus Competibacter phosphatis clone SBRQ22显著增加.

In order to investigate the relationship between operation and biological community, different operational periods of biological phosphorus removal （BPR） including setup period, stable period and deteriorative period were analyzed in an anaerobic/aerobic sequencing batch reactor （SBR）. PCR - DGGE protocol was employed for revealing succession of microbial community structure and changes of functional bacteria related to BPR in different periods. The setup period lasted 26 days, including lag phase and rising phase. During these two phases, phosphorus removal efficiency enhanced from less than 40% to 80%. After that, stable period started represented by stable phosphorus removal efficiency of more than 80%. Tetrasphaera elongate, Gemmatimonas aurantiaca and Uncultured γ - proteobacterium were dominant as functional microbes in stable period. Stable period lasted 80 days, and then the BPR went into deteriorative period with a phosphorus removal efficiency of less than 70%. Microbial community structure of stable period and deteriorative period varied greatly. Uncultured γ-proteobacterium, which acted as potential polyphosphate accumulating organisms （PAOs）, was eliminated from the reactor while the major competitor Candidatus Competibacter phosphatis clone SBRQ22 increased significantly leading to deterioration of BPR system.