一株嗜水气单胞菌HS01的偶氮还原脱色特性

摘要

[Objective] The purpose was to study azo reduction activity in the strain Aeromonas hydrophila HS01 under anaerobic conditions.[Methods] We established the anaerobic system of HS01/electron donor/azo dye to investigate the ability of strain HS01 to obtain energy for growth by coupling the oxidation of electron donors to azo reduction,and further explore the enhanced azo microbial reduction by the presence of Fe(Ⅲ) oxides.[Results] Within 30 h,HS01 could reduce 0.45 mmol/L orange Ⅰ at the expense of 4.35 mmol/L glucose,and the active cells increased by 27 times in the treatments of HS01/glucose/orange Ⅰ.The decolorization rate of orange Ⅰ reached 87％,85％,88％,and 90％,respectively,when citrate,glycerol,sucrose or glucose served as the electron donor.It showed different decolorization rate by pH of 5-10 and 0.5-5.0 mmol/L of initial concentrations of orange Ⅰ.In the system of HS01/glucose/orange with α-FeOOH,decolorization rate increased from 90％ to 95％.[Conclusion] HS01 was capable of anaerobic respiration on orange Ⅰ as the sole terminal electron acceptor with glucose as the electron donor.The decolorization rate depended on the types of electron donor,pH and initial concentrations of azo:citrate,glycerol,sucrose or glucose could serve as an effective electron donor for dissimilatory azo reduction,whereas formate,acetate,propionate,lactate and ethanol do theopposite; pH of 6.0-8.0 was optimum for azo reduction by HS01.Dissimilatory Fe(Ⅲ) reduction and azo reduction by strain HS01 occurred simultaneously,and the presence of Fe(Ⅲ) oxides would enhance orange Ⅰ decolorization.%[目的]研究嗜水气单胞菌HS01的偶氮染料还原脱色特性.[方法]建立HS01/偶氮染料/电子供体序批式厌氧反应体系,研究Fe(Ⅲ)/腐殖质还原菌HS01以偶氮染料为电子受体的厌氧呼吸特性及影响因素；并构建HS01/偶氮染料/电子供体/铁氧化物体系,探讨铁氧化物对HS01偶氮还原的影响.[结果]HS01可将金橙Ⅰ迅速还原,菌体增殖；柠檬酸、丙三醇、蔗糖和葡萄糖体系中,16h金橙Ⅰ的脱色率分别达87％、85％、88％、90％；不同pH和金橙Ⅰ初始浓度条件下的脱色率不同；在反应体系中加入α-FeOOH,脱色率从90％增加至95％,Fe(Ⅱ)生成量与无染料对照体系相当.[结论]HS01能以葡萄糖为电子供体,金橙Ⅰ为唯一电子受体,进行厌氧呼吸；蔗糖、柠檬酸、丙三醇也可作为有效的电子供体,脱色率依次递减；甲酸、乙酸、乳酸、乙醇及丙酸不能作为HS01厌氧呼吸的电子供体.金橙Ⅰ脱色的最佳pH范围为6.0-8.0;高浓度(2.0 mmol/L)金橙Ⅰ负荷下,HS01仍保持高脱色率(＞85％).在HS01/α-FeOOH/金橙Ⅰ体系中,异化铁还原作用与偶氮呼吸作用同时发生,异化铁还原能促进偶氮脱色,而脱色对Fe(Ⅲ)还原没有明显影响.这可为铁/腐殖质还原菌在环境修复和废水处理等领域的应用提供研究积累.