活性污泥积累PHB (Poly-β-hydroxybutyrate)及其菌群多样性分析

The community diversity of activated sludge accumulation PHB (ploy-β-hydroxybutyrate)

摘要:

【目的】通过调整活性污泥在驯化过程中碳、氮、磷比例以及供氧模式, 以提高其积累PHB的能力。应用PCR-DGGE定期对驯化期间菌群动态进行分析。【方法】以乙酸钠为碳源, 在SBR (Sequencing batch reactor) 内以厌氧/好氧 (A/O) 交替的驯化模式, 逐级提高碳源浓度, 限制氮源浓度, 人为创造营养不均衡条件来逐步提高活性污泥积累PHB的能力。【结果】当碳浓度逐步提高, COD升高至1 200 mg/L, COD/N/P为1 200/9.6/30时, 活性污泥中PHB积累量达到最大, 占细胞干重的64.2%。【结论】驯化过程中逐步提高COD负荷, 并增加COD/N的值有利于PHB积累, 利用苏丹黑和Albert法染色显示菌群内产PHB菌占很大比例, 透射电镜显示菌体胞内含有大量白色PHB颗粒。经DGGE菌群动态分析, 发现驯化过程中菌群种类出现较为明显的演替, 而在一个反应周期(6 h)内菌种数量也有一定改变。驯化获得的高产PHB的菌群中含Acinetobacter、Bacillus、Bacteroidetes、Chryseobacteria 及proteobacteria等5个属的微生物, 菌群多样性较为丰富。

Abstract:

[Objective] By adjusting carbon, nitrogen and phosphorus ratio and domestication model, to improve the ability of active sludge synthesis PHB. PCR-DGGE technology was used to study microbial diversity of domesticated flora. [Methods] In A/O alternate cycle SBR, we used sodium acetate as substrate, gradually improve carbon source concentration and limit concentration of nitrogen source, to create nutrition disequilibrium to gradually improve the content of PHB within activated sludge. [Results] When the COD reach 1 200 mg/L and COD/N/P=1 200/9.6/30, activated sludge synthetized PHB concentration reached the maximum of 64.2 wt% of the dry weight of cells. [Conclusion] In the process of domesticated sludge accumulation of PHB gradually increased, Sudan black, Albert staining and transmission electron microscopy images results showed improve carbon concentration and limit the concentration of carbon which domestication way promote the activated sludge accumulation PHB. DGGE was periodically used to identify the community diversity during the course of domestication and culture period. The population of the activated sludge was belonged to Acinetobacter, Bacillus, Bacteroides sp., Chryseobacteria sp. and proteobacteria.