Bacterial diversity and function of aerobic granules engineered in a sequencing batch reactor for phenol degradation
Bacterial diversity and function of aerobic granules engineered in a sequencing batch reactor for phenol degradation
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DOI：
10.1128/aem.70.11.6767-6775.2004
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发表时间：
2004-11-01
影响因子：
4.4
通讯作者：
Tay, STL
中科院分区：
文献类型：
--
作者：
Jiang, HL;Tay, JH;Tay, STL
好氧颗粒污泥是微生物的自固定化聚集体，代表了一种相对较新的用于生物废水处理的细胞固定化形式。本研究采用基于培养和非培养的方法，对序批式反应器中好氧苯酚降解颗粒污泥中的细菌多样性和功能进行了研究。PCR扩增的16 S rRNA基因的变性梯度凝胶电泳（DGGE）分析表明，作为种子污泥发展成颗粒的微生物群落的重大转变。培养分离和DGGE分析证实了β-变形菌和高G +C革兰氏阳性菌在苯酚降解好氧颗粒中的优势。从颗粒污泥中分离到的10株苯酚降解菌中，PG-01、PG-02和PG-08的16 S rRNA基因序列与DGGE指纹图谱中属于好氧颗粒污泥的优势条带的部分序列相匹配。菌株PG-01的数量优势通过分离、DGGE和与菌株特异性探针的原位杂交来确认，并且随后鉴定了PG-01所具有的使其能够在颗粒内胜过和支配其他微生物的关键生理特性。该菌株可被视为一种功能优势菌株，并可能对颗粒中的苯酚降解有显着贡献。另一方面，菌株PG-08具有低的比生长速率和低的苯酚降解能力，但显示出高的自聚集倾向。通过分析这两个菌株在好氧颗粒污泥中的作用，提出了好氧颗粒污泥微生物群落的功能模型。该模型对合理化生态系统工程具有重要意义。
Aerobic granules are self-immobilized aggregates of microorganisms and represent a relatively new form of cell immobilization developed for biological wastewater treatment. In this study, both culture-based and culture-independent techniques were used to investigate the bacterial diversity and function in aerobic phenol-degrading granules cultivated in a sequencing batch reactor. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA genes demonstrated a major shift in the microbial community as the seed sludge developed into granules. Culture isolation and DGGE assays confirmed the dominance of beta-Proteobacteria and high-G+C gram-positive bacteria in the phenol-degrading aerobic granules. Of the 10 phenol-degrading bacterial strains isolated from the granules, strains PG-01, PG-02, and PG-08 possessed 16S rRNA gene sequences that matched the partial sequences of dominant bands in the DGGE fingerprint belonging to the aerobic granules. The numerical dominance of strain PG-01 was confirmed by isolation, DGGE, and in situ hybridization with a strain-specific probe, and key physiological traits possessed by PG-01 that allowed it to out-compete and dominate other microorganisms within the granules were then identified. This strain could be regarded as a functionally dominant strain and may have contributed significantly to phenol degradation in the granules. On the other hand, strain PG-08 had low specific growth rate and low phenol degradation ability but showed a high propensity to autoaggregate. By analyzing the roles played by these two isolates within the aerobic granules, a functional model of the microbial community within the aerobic granules was proposed. This model has important implications for rationalizing the engineering of ecological systems.