一株高效反硝化聚磷菌的筛选及脱氮除磷效能

Isolation and identification of denitrifying polyphosphate-accumulating organisms and its efficiency of nitrogen and phosphorus removal

高效的反硝化聚磷菌的分离及脱氮除磷效能的研究对于反硝化聚磷机理及脱氮除磷工艺的创新具有重要意义.采用专性培养基,从稳定运行的A/O/A SBR反应器中分离得到16株反硝化聚磷菌.通过poly-P染色试验、吸磷试验、硝酸盐还原产气及脱氮效能试验相结合的方法,筛选得到一株高效的反硝化聚磷菌Q-hrb05.实验结果表明:经16S rDNA初步鉴定菌株Q-hrb05为芽孢杆菌,相似度为99%.菌株Q-hrb05的16S rDNA序列登录GenBank,登录号为GU214826.结合生理生化结果,确定菌株Q-hrb05为芽孢杆菌.菌株Q-hrb05属于好氧反硝化菌,且除磷效率高,在12 h内除磷率可达85%.经过厌氧/缺氧培养,发现菌株Q-hrb05的吸磷率与菌株内PHB的变化呈正相关.厌氧段,PHB在菌体内合成,约占细胞干质量的12%,释磷率为66%;缺氧段,菌体内PHB质量下降,吸磷率为92%.

In this paper,16 denitrifying phosphate-accumulating organisms（DNPAOs） were isolated in the special medium from the anaerobic/aerobic/anoxic SBR reactor,and the most efficient DNPAOs called Q-hrb05,was screened by a phosphate uptake experiment,where nitrates were denitrified to gas and through inspection of the poly-P.Strain Q-hrb05 was identified by 16S rDNA gene analysis,and the accession number of 16 S rDNA gene sequence of strain Q-hrb05 in GenBank was GU214826.The result showed that the strain Q-hrb05 belonged to Bacillus sp,of which the homology could reach to 99%,that also corresponded to the result of biochemical features.The average phosphorus uptake rate of strain Q-hrb05 was at 85% within 12 hours,and it had the denitrification capacity in the aerobic condition.It could be found that the phosphorus uptake rate was related to the content change of PHB.Under anaerobic condition,the maximal P-release rate was 66%,which could reach to 12% of the dry cell weight.The P-uptake rate was 92% with the decreasing of PHB content.