【作者】 张帆；

【导师】 杨琦； 尚海涛；

【作者基本信息】 中国地质大学（北京） ， 生物化学与分子生物学， 2013， 硕士

【摘要】 多环芳烃（PAHs）具有强烈的三致作用，属于持久性有机污染物，PAHs进入土壤环境后可以在粮食和蔬菜等作物体内中富集，并通过食物链威胁着人类健康。因此，为更经济有效地去除污染土壤中的PAHs，本研究从土壤中驯化、筛选出萘、菲降解菌，考察了单一菌株的性质及对萘、菲降解特性；同时考察了华北亚粘土对萘、菲的去除。实验结论如下：（1）经过加萘驯化后，华北亚粘土去除萘的最佳pH值为7；萘初始浓度的降低、温度的升高都将增大华北亚粘土对萘的去除率；抑菌对比实验表明华北亚粘土中存在能够降解萘的微生物。不同条件下华北亚粘土对萘的去除均较符合二级动力学。（2）经过加菲驯化后，华北亚粘土去除菲的最佳pH值为7；菲初始浓度的降低、温度的升高都将增大华北亚粘土对菲的去除率；抑菌对比实验表明华北亚粘土中存在能够降解菲的微生物。动力学方程拟合结果表明当pH小于等于7、菲初始浓度小于0.7mg/L、反应温度为15-20℃时，华北亚粘土对菲的去除较符合二级动力学。（3）本研究从华北亚粘土、黄土、成都亚粘土中共筛选出萘降解菌14株，菲降解菌11株。华北亚粘土中筛选出的5株萘降解菌、4株菲降解菌，革兰氏染色结果为：菌株HBN-Ⅱ、HBN-Ⅳ、HBF-Ⅰ和HBF-Ⅳ属于革兰氏阳性菌，HBN-Ⅰ、HBN-Ⅲ、HBN-Ⅴ、HBF-Ⅱ和HBF-Ⅲ则属于革兰氏阴性菌。上述株菌的基因鉴定结果为：HBN-Ⅰ，鞘氨醇杆菌；HBN-Ⅱ，红球菌；HBN-Ⅲ，假单胞菌；HBN-Ⅳ，分支杆菌；HBN-Ⅴ，马赛菌；HBF-Ⅰ，节杆菌属；HBF-Ⅲ，假红育菌属；HBF-Ⅳ，类诺卡氏菌属。（4）对于由华北亚粘土中筛选出的5株萘降解菌，各菌株对萘的降解能力依次为，HBN-Ⅱ>HBN-Ⅴ>HBN-Ⅰ>HBN-Ⅳ>HBN-Ⅲ。对于优势菌株HBN-Ⅱ降解萘，萘的初始浓度越大，萘的去除率越低；菌悬液接种量越大，萘的降解速率越快；降解的最佳pH条件为8，最适温度为30℃，且温度的影响要大于pH的影响；HBN-Ⅱ对萘的降解符合一级动力学方程。菌株HBN-Ⅱ降解萘的活化能为51.32kJ/mol；Monod动力学方程参数为=0.0348min^-1，=7.1166mg/L。（5）对于由华北亚粘土中筛选出的4株菲降解菌，各菌株对菲的降解能力依次为，HBF-Ⅳ>HBF-Ⅱ>HBF-Ⅰ>HBF-Ⅲ。对于优势菌株HBF-Ⅳ降解菲，菲的初始浓度越大，菲的去除率越低；菌悬液接种量越大，菲的降解速率越快；降解的最佳pH条件为7，最适温度为30℃，且温度的影响要大于pH的影响；HBF-Ⅳ对菲的降解符合一级动力学方程。菌株HBF-Ⅳ降解菲的活化能为108.55kJ/mol；Monod动力学方程参数为=0.0025min^-1，=0.5027mg/L。更多还原

【Abstract】 PAHs is one of the Persistent Organic Pollutants （POPs） and has potentialcarcinogenic effects on human. PAHs in the soil environment can be accumulated incrops and vegetables, which will threat human health through the food chain. In orderto find a more cost-effective way to remove PAHs from contaminated soil, singlestrains were separated from PAHs contaminated soil, that took naphthalene orphenanthrene as growth substrate. The strains and their properties were identified. Theremoval of naphthalene or phenanthrene by North China loam were studied. Specificconclusions were as follows:（1） The optimal initial pH is7for the removal of naphthalene by North Chinaloam, which used for domestication of naphthalene-degrading bacteria. The decreaseof initial concentration of naphthalene and the increase of temperature promoted theremoval rate. Bacteriostatic contrast experiment suggested that naphthalene-degradingstrain exists in North China loam. The removal of naphthalene by North China loamfollowed second-order kinetics under different pH, initial naphthalene concentrationsand temperatures conditions.（2） The optimal initial pH is7for the removal of phenanthrene by North Chinaloam, which used for domestication of phenanthrene-degrading bacteria. The decreaseof initial concentration of phenanthrene and the increase of temperature promoted t heremoval rate. Bacteriostatic contrast experiment suggested thatphenanthrene-degrading strain exists in North China loam. The removal ofphenanthrene by North China loam followed second-order kinetics under acid orneutral conditions, initial phenanthrene concentration less than0.7mg/L and thereaction temperature ranging from15to20℃.（3） Fourteen naphthalene-degrading strains and eleven phenanthrene-degradingstrains were screened from North China loam, loess and Chengtu loam. Moreover, thestrains HBN-Ⅱ, HBN-Ⅳ, HBF-Ⅰ and HBF-Ⅳ screened from North China loamwere gram-positive bacteriums, and strains HBN-Ⅰ, HBN-Ⅲ, HBN-Ⅴ, HBF-Ⅱ andHBF-Ⅲwere gram-negative bacterias. The results of16S rDNA PCR-RFLP showed that the strains HBN-Ⅰ, HBN-Ⅱ, HBN-Ⅲ, HBN-Ⅳ, HBN-Ⅴ, HBF-Ⅰ, HBF-Ⅲ andHBF-Ⅳ were classified as Sphingobacterium, Rhodococcus, Pseudomonas,Mycobacterium, Massilia, Arthrobacter, Pseudorhodoferax and Nocardioidesrespectively.（4） Five naphthalene-degrading strains screened from North China loam: Thestrain HBN-Ⅱ was dominant strain and presented the best degradation activity,followed by HBN-Ⅴ, HBN-Ⅰ, HBN-Ⅳ, HBN-Ⅲ. For strain HBN-Ⅱ degradation ofnaphthalene, the greater the initial concentration of naphthalene was, the lower theremoval rate was; the more the biomass was, the faster the removal rate was; theoptimal pH and temperature were8and30℃, respectively. Compared to the effect ofpH, temperature has more effect on the removal rate. The degradation kineticsconformed well to first-order kinetics. The degradation activation energy ofnaphthalene was51.32kJ/mol. The degradation kinetics of naphthalene for strainHBN-Ⅱ fitted well with Monod kinetics. The maximum specific utilization rate andhalf saturation constant were0.0348min^-1, and7.1166mg/L, respectively.（5） Four phenanthrene-degrading strains screened from North China loam: Thestrain HBF-Ⅳ was dominant strain and presented the best degradation activity,followed by HBF-Ⅱ, HBF-Ⅰ, HBF-Ⅲ. For strain HBF-Ⅳ degradation ofphenanthrene, the greater the initial concentration of phenanthrene was, the lower theremoval rate was; the more the biomass was, the faster the removal rate was; theoptimal pH and temperature were7and30℃, respectively. Compared to the effect ofpH, temperature has more effect on the removal rate. The degradation kineticsconformed well to first-order kinetics. The degradation activation energy ofphenanthrene was108.55kJ/mol. The degradation kinetics of phenanthrene for strainHBF-Ⅳ fitted well with Monod kinetics. The maximum specific utilization rate andhalf saturation constant were0.0025min^-1and0.5027mg/L, respectively.更多还原