一株好氧反硝化菌的分离鉴定及其除氮特性

Identification and denitrification of an aerobic bacterium

摘要:

摘要: 【目的】生物除氮中反硝化菌具有重要的作用，需氧反硝化菌研究较少，有着很好的应用潜力，本研究主要从环境样品中分离具有高效去除铵氮和亚硝酸盐氮活性的好氧反硝化菌，并对其分类及除氮特性进行研究。【方法】以高效去除铵氮、除亚硝酸盐氮和好氧反硝化能力为主要指标，从富营养化的池塘淤泥水和工厂污泥样品中进行菌株分离筛选。通过生理生化特点以及16S rRNA 序列分析对活性最好的菌株进行初步鉴定。在好氧条件下，分别以NO－3-N、NH+4-N和NO－2-N 作为唯一氮源，考察菌株的好氧反硝化特性、去除铵氮和亚硝酸

Abstract:

Abstract: ［Objective］ Denitrifying bacteria play an important role in the biological nitrogen removal process，especially the aerobic denitrifying bacteria． However，there are few studies on aerobic denitrifying bacteria． The present study aimed at the isolation of aerobic denitrifying bacteria with high ammonium and nitrite nitrogen removing ability from environmental samples，and its phylogeny and denitrifying characteristics.［Methods］ Based on the aerobic denitrifying activity，ammonium and nitrite nitrogen removing ability， the strains were isolated from sludge，water and sediment in a eutrophicated pond． A strain with the highest activities was identified according to its morphological，physiological and biochemical properties and phylogenetic analysis of its 16S rRNA sequence． By using NO－3-N，NH+4-N and NO－2-N as the sole nitrogen source respectively，its denitrifying characteristics，and the effects of culture conditions such as initial pH of medium，temperature，carbon source，shaking speed on the ability of removing ammonium and nitrite nitrogen，were investigated under aerobic condition．［Results］Among the isolated strains，strain C-4 showed the highest ability of removing ammonium and nitrite nitrogen． Strain C-4 was identified as Acinetobacter sp．Under the conditions of sodium citrate as carbon source，temperature 30℃ ，shaking speed 120 r/min，cell age of 18 h，pH 8.5 for 200 mg/L NH4+-N medium and pH 7.5 for 100 mg/L NO2 －-N medium，the net removal efficiency of nitrogen were 65.8% and 47.8% after 15 h and 12 h，respectively．［Conclusion］ An aerobic denitrifying strain Acinetobacter sp．C-4 ( HQ896038) was isolated from water pond，and it exhibited high net removal efficiency of nitrogen in relative media． The net removal efficiency of nitrogen of strain C-4 was 73. 04% in dealing with a eutrophicated pond water．