白囊耙齿菌ZK1对17β-雌二醇的降解特征

Degradation Characteristics of 17β-estradiol by Irpex lacteus ZK1

17β-雌二醇(E2)是畜禽养殖业排放的一种新兴污染物,痕量水平便可对水生生物的生殖系统造成伤害,通过纯培养研究了1株白囊耙齿菌ZK1对E2的降解潜力。结果表明:菌株ZK1能以E2为唯一碳源进行生长,降解E2的温度和pH适应范围较宽,最佳温度和pH分别为35℃和6。菌株ZK1以NH4^+和NO3^-为唯一氮源培养7 d后,对E2的降解率分别为77.6%和65.4%。葡萄糖共存可提高菌株ZK1对E2的降解速率。菌株ZK1对低浓度的E2具有较高的降解能力,随着浓度的增加,降解率逐渐下降,增加至20 m/kg,在第10天时,E2的降解率降低至81.4%。菌株ZK1在降解E2的过程中会积累中间代谢产物——雌酮(E1),随着时间的延长,菌株ZK1会同时降解E1和E2。研究表明,菌株ZK1降解E2时具有适应能力强和可进行连续降解的优点,对治理E2污染具有潜在的应用价值。

17β-estradiol(E2)is a new pollutant from livestock and poultry industry,and its trace levels can cause harm to the reproductive system of aquatic organisms.The degradation potential of strain ZK1 for E2 was studied by pure culture.The results showed that strain ZK1 could grow with E2 as sole carbon source.The suitable temperature and pH for degradation of E2 were wide.The optimum temperature and pH were 35℃and 6,respectively.Strain ZK1 was cultured with NH4^+and NO3^-as the sole nitrogen source.After 7 days,the degradation rates of E2 were 77.6%and 65.4%,respectively.When glucose was a coexisting carbon source,the degradation rate of E2 by strain ZK1 could be increased.Strain ZK1 had high capability of degrading low concentration E2.With the increase of concentration,the degradation rate decreased gradually,and when the concentration was increased to 20 mg/kg,the degradation rate of E2 decreased to 81.4%at 10 days.During the degradation of E2,strain ZK1 accumulated the intermediate metabolite estradiol(El).Strain ZK1 could degrade El and E2 simultaneously with the prolongation of time.The results showed that strain ZK1 has the advantages of strong adaptability and continuous degradation.It has potential ap-plication value in the treatment of E2 pollution.