反硝化除磷菌的筛选鉴定及生物特性研究

Isolation,Identification and Biological Characteristics of Denitrifying Polyphosphate-accumulating Organisms

采用反硝化培养基分离得到菌株ZQN4,通过好氧吸磷试验、硝酸盐还原产气试验及异染颗粒和PHB颗粒染色,确认其为反硝化除磷菌。结合生理生化检测和16S rRNA测序鉴定菌株ZQN4为芽胞杆菌属。菌株ZQN4的生长曲线比较典型,潜伏期为2 h左右,对数生长期为14～16 h,18 h后进入稳定期和衰亡期,吸磷主要发生在对数生长期。Logistic方程可对反硝化除磷菌的生长动力学模型进行较好的描述。菌株ZQN4的厌氧释磷/缺氧吸磷试验表明,其在厌氧段释磷并合成PHB,在缺氧段以NO3--N为电子受体氧化PHB,进行同步反硝化除磷。与其他4株反硝化除磷菌的复配试验结果表明复配效果不理想,相对于单株菌并未表现出优势。

The strain ZQN4 was isolated from denitrifying medium and confirmed as denitrifying polyphosphate-accumulating organism （DPAO） by aerobic phosphorus uptake, nitrate reduction, metachromatic granules and PHB granules dyeing. The strain ZQN4 was identified as Bacillus sp. based on the physiological and biochemical characters and 16S rRNA sequence. The growth curve of strain ZQN4 was typical, the latency was about 2 h, and the logarithmic growth phase was 14 to 16 h. After 18 h, the strain went to stationary phase and decline phase. Phosphorus uptake mainly occurred in logarithmic growth phase. The Logistic equation can suitably represent the growth kinetic model of DPAO. Tests of anaerobic phosphorus release/anoxic phosphorus uptake showed that strain ZQN4 could release phosphorus and synthetize PHB under anaerobic condition, and take NO^3- -N as acceptor to oxidize PHB under anoxic condition, thus achieving simultaneous denitrifying phosphorus removal. The effects of combining strain ZQN4 with other four DPAO strains were not satisfactory. The removal performance was not superior to that of single strain.