金属离子对蒽、菲、芘生物降解过程的影响

The Effect of Metallic Ions on the Biodegradation of Anthracene,Phenanthrene and Pyrene

对驯化筛选的多环芳烃(PAHs)高效降解菌CN4与CN2进行了深入研究,澄清了金属离子对其降解多环芳烃的作用,得出结论:对于CN2、CN4降解菌,Mn2+与常量Ca2+、Mg2+同时存在于降解体系中时,对蒽和菲降解起到明显促进作用。Cu2+和常量元素Ca2+、Mg2+混合对菲降解也起到促进作用,但没有Mn2+的促进作用明显。不加任何常量和微量金属元素离子的体系对蒽、菲、芘的降解作用仅次于含Mn2+的降解体系,加入Cu2+、Ca2+、Mg2+、Fe3+、Zn2+对CN2降解蒽、芘产生抑制作用,加入Ca2+、Mg2+、Fe2+、Zn2+对CN2降解菲产生促进作用。Mn2+主要是在降解过程中发挥作用的,外加不同浓度的Mn2+制备的菌悬液,对芘的降解作用基本没有差别。在制备菌悬液时加入Mn2+,菌体对Mn2+有富集作用,但Mn2+的存在与否并不影响菌体的生长繁殖状况。降解体系中加入Mn2+能够有效促进降解过程的进行,加入0.5 mmol/L的Mn2+对CN4菌株降解芘的促进作用最大,而在降解体系中一次性加入5.0 mmol/L的Mn2+则会对降解产生抑制作用。

We do further study on the degradation of PAHs by the screening bacterium CN4 and CN2 with high efficiency from which are domesticated,clarify the degradation effect of the metallic ion on the PAHs,and obtain the following conclusion.For bacillus sp.CN2 and flavobacterium sp.CN4,the degradation rates of anthracene and phenanthrene are obviously enhanced when Mn2＋ and the normal amount Ca2＋ and Mg2＋ coexists.The degradation efficiency of phenanthrene is boosted when Cu2＋ mixed with Ca2＋ and Mg2＋,but not as obvious as Mn2＋.For the degradation system without adding normal amount and trace amount metallic iron,the degradation efficiency is rank only second to the degradation system contained Mn2＋.The system that adding with Cu2＋,Ca2＋,Mg2＋,Fe3＋,Zn2＋ could restrain the degradation of anthracene and pyrene by CN2,while adding with Ca2＋,Mg2＋,Fe2＋,Zn2＋ could enhance the degradation of phenanthrene by CN2.The enhancement effect of Mn2＋ is only in the process of degradation,but not in the process of bacteria suspension growth.Adding Mn2＋ could effectively promote the degradation process.The best concentration of Mn2＋ is 0.5 mmol/L,adding 5.0 mmol/L of Mn2＋ would restrain the degradation process.