17β-雌二醇降解微生物筛选及环境因素的影响

Screening of 17β-estradiol degradation microorganisms and the influence of environmental factors

为提高污水中17β-雌二醇(E2)的去除效率,筛选洱海沉积物中E2的优势降解微生物,并在不同环境条件下进行生物吸附和生物降解E2过程的研究。结果表明:大肠杆菌是E2降解的优势菌种,其对E2的生物去除是快速吸附及持续降解的共同作用过程。经大肠杆菌降解3 d后,1.00 mg/L E2去除率约为70.42%。生物吸附主要受pH值、生物量的限制,在弱碱性(pH=8)环境下吸附效果最佳。在适宜的浓度下,电子供体、H_(2)O_(2)、腐殖质和重金属可以有效促进E2的生物降解。当葡萄糖、甲酸钠、H_(2)O_(2)、腐殖质、Zn^(2+)和Cu^(2+)浓度分别为40.0 mg/L、10.0 mg/L、3.0 mmol/L、2.0~15.0 mg/L、0.5 mg/L及0.5 mg/L时,E2的生物降解率提高近12.41%~57.47%。由此可见,洱海沉积物中筛选的大肠杆菌具有较好的E2去除能力,但其受众多环境因素的影响,通过调节合适的环境条件可极大程度地促进E2的生物去除效率。

In order to improve the removal efficiency of 17β-estradiol(E2)in wastewater,the predominant microorganisms that degrade E2 in the Erhai Lake sediment were screened,and the biosorption and biodegradation of E2 in different environment were studied in this study.The results showed that Escherichia coli(E.coli)is the dominant strain of E2 degradation,and its biological removal process of E2 is a combined process of rapid adsorption and continuous degradation.The removal rate of E2 with an initial concentration of 1.00 mg/L was about 70.42%after being degraded by E.coli for 3 days.Biosorption is mainly limited by pH value and biomass,and the highest adsorption efficiency was obtained in a weakly alkaline environment(pH=8).Electron donors,hydrogen peroxide,humus and heavy metals can effectively promote the biodegradation of E2 at appropriate concentrations.When the concentrations of glucose,sodium formate,H_(2)O_(2),humus,Zn^(2+)and Cu^(2+)was 40 mg/L,10 mg/L,3 mmol/L,2-15 mg/L,0.5 mg/L and 0.5 mg/L,respectively,the biodegradation efficiency of E2 increased by 12.41%-57.47%.Draw a conclusion from the above results,the E.coli screened from the Erhai Lake sediment exhibits excellent E2 removal ability,but this process is affected by many environmental factors,and the removal efficiency of E2 can be greatly promoted by adjusting appropriate environmental conditions.