生物技术通报2023，Vol.39Issue(12)：237-249,13.DOI:10.13560/j.cnki.biotech.bull.1985.2023-0452
一株耐低温异养硝化-好氧反硝化菌的分离鉴定及其脱氮特性
Isolation and Identification of a Psychrotolerant Heterotrophic Nitrification-aerobic Denitrification Bacterium and Its Nitrogen-removing Characteristics
摘要
Abstract
In order to improve the biological nitrogen removal efficiency of low-temperature wastewater,a psychrotolerant heterotrophic nitrification and aerobic denitrification bacterium was isolated from soil and river sediment in cold regions,and its nitrogen removal characteristics and pathway were investigated.The isolated bacterium was identified based on its colony and cell morphological observation as well as 16S rRNA gene sequence analysis.The nitrification,denitrification,and simultaneous nitrification and denitrification performance of the strain were investigated with NH4+-N,NO3--N,and NO2--N as the sole nitrogen source and NH4+-N and NO3--N as mixed nitrogen sources.The nitrogen-removing functional enzyme genes of the strain were amplified by polymerase chain reaction(PCR)to speculate the nitrogen-removing pathway at low-temperature.A heterotrophic nitrification and aerobic denitrification bacterium was screened from the river sediment and identified as Pseudomonas veronii,named P.veronii DH-3.When strain P.veronii DH-3 was cultured aerobically for 48 h at 10℃with NH4+-N,NO3--N,and NO2--N as the sole nitrogen sources(N 105 mg/L),the corresponding nitrogen removal efficiencies were 99.07%,96.89%,and 90.29%,respectively,without accumulation of nitrite.When NH4+-N and NO3--N were used as mixed nitrogen sources,NH4+-N was completely removed in 48 h and the NO3--N removal rate was 87.09%,indicating that strain P.veronii DH-3 had excellent simultaneous nitrification and denitrification performance at 10℃.The nitrogen balance analysis results showed that when NO3--N and NO2--N were the sole nitrogen sources respectively,the conversion rates of nitrogenous gas and intracellular nitrogen were lower than those of NH4+-N,indicating that the heterotrophic nitrification ability of the strain DH-3 was stronger than that of aerobic denitrification.Meanwhile,the successful expressions of denitrification functional genes hao,napA,nirS,nirK,cnorB,and nosZ further confirmed that the heterotrophic nitrification and aerobic denitrification ability of strain DH-3.Based on the above results,it was speculated that the main nitrogen-removing pathway of the strain was heterotrophic nitrification,aerobic denitrification,and assimilation.These findings indicate that the psychrotolerant P.veronii DH-3 possesses excellent heterotrophic nitrification and aerobic denitrification capability,which provides the theoretical support for biological purification of low-temperature nitrogen wastewater.关键词
耐低温菌/生物脱氮/异养硝化/好氧反硝化/分离鉴定/脱氮功能基因/假单胞菌Key words
psychrotolerant bacterium/biological nitrogen removal/heterotrophic nitrification/aerobic denitrification/isolation and identification/nitrogen removal functional genes/Pseudomonas引用本文复制引用
董怡华,王凌潇,任涵雪,陈峰..一株耐低温异养硝化-好氧反硝化菌的分离鉴定及其脱氮特性[J].生物技术通报,2023,39(12):237-249,13.基金项目
沈阳市科技计划项目(21-108-9-25),"十三五"国家水体污染控制与治理科技重大专项(2018ZX07601-002) （21-108-9-25）
