芘高效降解菌ZQ5的培养条件及无机元素对其降解效率的影响

以从我国最大的石油污水灌区之一——沈抚灌区污染土壤分离到的以芘为惟一碳源、能源生长的高效降解菌株ZQ5为实验材料,通过对菌株ZQ5培养条件的优化,以及采用摇瓶振荡培养方法测定菌株ZQ5对不同浓度芘的降解率,表明:菌株ZQ5在30℃振荡培养16 d后对150 mg/L芘的降解率为90.31%。通过模拟稻田施用N、P和K肥等的土壤环境,探索了无机营养元素对降解菌ZQ5降解能力的影响,发现土壤中混合加入N、P和K无机营养元素的降解率能达到82%以上,比单加某种营养元素对降解菌ZQ5的降解效果好。本研究结果可以指导稻田PAHs的原位生物修复。     

Linking empirical estimates of body burden of environmental chemicals and wellness using NHANES data

Biomonitoring of industrial chemicals in human tissues and fluids has shown that all people carry a “body burden” of synthetic chemicals. Although measurement of an environmental chemical in a person's tissues/fluids is an indication of exposure, it does not necessarily mean the exposure concentration is sufficient to cause an adverse effect. Since humans are exposed to multiple chemicals, there may be a combination effect (e.g., additive, synergistic) associated with low-level exposures to multiple classes of contaminants, which may impact a variety of organ systems. The objective of this research is to link measures of body burden of environmental chemicals and a “holistic” measure of wellness. The approach is demonstrated using biomonitoring data from the National Health and Nutrition Examination Surveys (NHANES). Forty-two chemicals were selected for analysis based on their detection levels. Six biological pathway-specific indices were evaluated using groups of chemicals associated with each pathway. Five of the six pathways were negatively associated with wellness. Three non-zero interaction terms were detected which may provide empirical evidence of crosstalk across pathways. The approach identified five of the 42 chemicals from a variety of classes (metals, pesticides, furans, polycyclic aromatic hydrocarbons) as accounting for 71% of the weight linking body burden to wellness. Significant interactions were detected indicating the effect of smoking is exacerbated by body burden of environmental chemicals. Use of a holistic index on both sides of the exposure-health equation is a novel and promising empirical “systems biology” approach to risk evaluation of complex environmental exposures.     

黄河中下游水体中多环芳烃的分布及来源

对小浪底至山东东明段黄河干、支流水、悬浮物和沉积物进行了采样分析.结果表明,干流水相∑15PAHs浓度范围为179～369ng/L,其中除焦巩桥外其它断面苯并(a)芘均超过国家饮用水标准;支流水相浓度均高于相应干流,尤其是富含低环PAHs的孟州一干渠对干流沉积相浓度有较大影响.与水相相比,悬浮、沉积相中PAHs检出种类较多,干流悬浮相∑13PAHs浓度范围为54～155μg/kg,且各环PAHs与悬浮相中TOC含量间存在一定正相关.干流沉积相∑13PAHs浓度范围为31～133μg/kg,其4、5、6环P     

酶联免疫吸附分析法测定苯并(a)芘和多氯联苯

对苯并(a)芘作了五种不同的化学修饰,并与载体蛋白交联,制备出十四种单克隆抗体.经单克隆抗体的筛选和实验条件的优化,建立了测定苯并(a)芘的酶联免疫吸附分析法.以4,4'-二氯联苯为测定多氯联苯的酶联免疫吸附分析法的起始物,作了二种化学修饰,制备出九种多克隆抗体,建立了以羊抗多氯联苯抗体为基础的酶联免疫吸附分析法,并用于土壤中多氯联苯的测定.     

Photochemical behavior of benzo[a]pyrene on soil surfaces under UV light irradiation

The rates of photodegradation and photocatalysis of benzo [a]pyrene （BaP） on soil surfaces under UV light have been studied. Different parameters such as temperature, soil particle sizes, and soil depth responsible for photodegradation, catalyst loads and wavelength of UV irradiation blamed for photocatalysis have been monitored. The results obtained indicated that BaP photodegradation follows pseudo-first-order kinetics. BaP photodegradation was the fastest at 30℃ . The rates of BaP photodegradation at different soil particle size followed the order： less than 1 mm〉less than 0.45 mm〉less than 0.25 mm. When the soil depth increased from 1 mm to 4 ram, the half-life increased from 13.23 d to 17.73 d. The additions of TiO2 or Fe2O3 accelerated the photodegradation of BaP, and the photocatalysis of BaP follows pseudo-first-order kinetics. Changes in catalyst loads of TiO2 （0.5%, 1%, 2%, and 3% （wt）） or Fe203 （2%, 5%, 7%, and 10% （wt）） did not significantly affect the degradation rates. Both BaP photocatalysis in the presence of TiO2 and Fe2O3 were the fastest at 254 nm UV irradiation.     

Levels of PAHs in the soils of Belgrade and its environs

Polycyclic aromatic hydrocarbons (PAHs) were analysed in 39 soil samples (0–10 cm upper layer) collected in Belgrade, the capital of Serbia. The sampling sites were randomly selected from urban, urban/recreational and rural areas; the samples were collected in April and December 2003 and July and October 2004. The sum of the 16 PAHs corresponding to the recreational zone (298 μg/kg) was close to the urban zone (375 μg/kg). Mean soil ΣPAH concentration from rural areas was 18 μg/kg dry weight. Comparing to values observed in the urbanized locations around the world, the overall levels of PAHs in this study are low. The PAH ratios obtained pointed to a domination of pyrogenically formed PAHs in the examined soils. The dominant PAHs in soil samples in urban zones were fluoranthene, benz[a]anthracene, phenanthrene and pyrene, mostly emitted from noncatalyst vehicles which are still in use in Serbia. The total carcinogenic potency for each sampling site was calculated. Regardless of the used carcinogenic activity factors, carcinogenic potency of 7 sites were 3–9 times higher than the reference ones indicating the increased carcinogenic burden of soils from these sites.     

8种植物叶片对城市大气苯并（a）芘（BaP）的吸收比较

城市化及汽车的发展导致城市大气中多环芳烃（PAHs）含量较高,强致癌作用污染物苯并（a）芘（BaP）含量也相应增高。植物是大气环境天然的过滤器,能滞留、吸附和累积空气中多种污染物。选择广州市8种常见行道树,4种乔木：红花羊蹄甲（Bauhiniablakeana）、腊肠树（Cassiafistula）、高山榕（Ficus...     

应用基于单克隆抗体的免疫传感器检测环境中的芘和苯并芘

多环芳烃是一类普遍存在的环境污染物,可以诱发癌症,对人们的健康造成严重威胁.本研究利用一种四环芳烃芘的衍生物作为半抗原,利用活泼酯法合成人工抗原免疫小鼠研制多环芳烃单克隆抗体.通过非竞争性ELISA与竞争性ELISA相结合的筛选方式得到一株单克隆抗体,命名为6A6.该抗体能特异性识别芘和苯并芘,其IC50值分别为8.1μg·L-1和6.8μg·L-1,对其他多环芳烃的交叉反应率均低于5%.在此基础上,建立了免疫传感器法对芘和苯并芘进行检测,线性范围为0.2~10.0μg·L-1.利用该方法对添加在水样中的样品进行回收,并与传统ELISA方法进行比对,结果证明传感器法检测更加快速且灵敏度更高.该方法可以用于含有芘和苯并芘的环境样品的快速筛选,可以在10 min内初步获得检测结果.     

蜡状芽胞杆菌对芘的降解特性及降解酶研究

考察蜡状芽胞杆菌(Bacillus cereus)对水体中芘的降解特性,分析其代谢产物和降解酶的活性.结果表明,1 mg·L-1Mn2+、0.1 mg·L-1Fe3+和10 mg·L-1葡萄糖混合物对芘的降解有明显促进作用;1 g·L-1菌体在120 h内对2.5μmol·L-1芘的降解率达到61.4%.利用LC-MS/MS分析芘代谢产物,检测到1-萘酚、2-萘酚、9-羟基菲和1-羟基芘4种单羟基多环芳烃,表明芘在单加氧酶作用下开环降解,且B.cereus能有效分解利用4种代谢产物,其最高利用率分别为100%、90.3%、98.3%和52.7%.酶活力分析实验结果表明,B.cereus具有的水杨酸羟化酶,邻苯二酚1,2-双加氧酶和邻苯二酚2,3-双加氧酶在芘的降解中起关键作用,其酶活力经芘诱导后均有明显提高.结合产物分析及酶活测定,推断B.cereus对芘的降解途径以及降解过程是由单加氧酶和双加氧酶联合起作用.