具有铁氧化功能的硝基苯降解菌的筛选及特性

采用硝基苯（NB）模拟废水对生物海绵铁体系进行驯化，筛选出一株具有铁氧化功能的高效硝基苯降解菌Y-9.经鉴定，菌株Y-9为节杆菌属（Arthrobacter sp.）.通过平行对比实验，考察了菌株Y-9适宜的生长条件，研究了菌株Y-9介入下的海绵铁体系对NB的强化降解效果及降解机理.结果表明，菌株Y-9在硝基苯初始含量为200mg/L的条件下生长良好，且适宜的温度为25~40℃，适宜的pH值为6~8.此外，菌株Y-9作用下的海绵铁体系较单纯海绵铁体系及介入普通活性污泥的海绵铁体系对硝基苯的降解率分别提高88.6%和32.2%.生物海绵铁体系中Fe²⁺、H₂O₂、·OH含量明显高于海绵铁体系，尤其是铁细菌Y-9作用下的生物海绵铁体系，Fe²⁺、H₂O₂、·OH含量最高，为体系发生较强类Fenton效应提供了条件.通过对降解产物的定量分析发现，菌株Y-9降解硝基苯的途径遵循部分还原途径.本研究初步揭示了生物海绵铁体系类Fenton效应机理，为经济有效地处理硝基苯废水提供了新思路.

Screening and degradation characteristics of nitrobenzene-degrading bacterium with iron oxidation function

An efficient iron bacterium used to degrade nitrobenzene (NB) was isolated from the biological sponge iron system domesticated through NB simulated wastewater. The strain was identified as Arthrobacte sp. The suitable growing conditions, as well as the degradation effect and mechanism in sponge iron system with strain Y-9, were carried out by the contrast experiments. Results indicated that strain Y-9 grew well when the initial concentration of NB was 200mg/L, and the optimal conditions for the biodegradation of NB by strain Y-9 were at 25~40℃ and pH 6~8. Besides, in contrast with the normal sponge irons system and the sponge irons system involved in ordinary activated sludge, the degradation rate of NB in biological sponge irons system at the present of strain Y-9 increased by 88.6% and 32.2%, respectively. The concentration of Fe²⁺, H₂O₂, and ·OH in the biological sponge iron system, especially the system inoculated with strain Y-9, were significantly higher than that of normal sponge iron system, thus, it could promote Fenton-like effect. Quantitative analysis of the degradation products revealed that strain Y-9 followed the partial reductive degradation pathway of NB. The research revealed the mechanism of Fenton-like effect in a biological sponge iron system, and it also provided a new way to treat NB wastewater effectively.