美国高产量化学品数据库在筛选优先化学品中的应用

介绍了美国高产量(HPV)化学品数据库的内容、格式和发展情况,以及采用HPV化学品数据筛选优先化学品的程序。HPV化学品数据库主要包括化学品数据、化学品毒性特征描述、优先风险评估以及数据资助方、提交方及测试方的相关信息,支持物质名称或化学文摘社登记号搜索。采用HPV化学品数据可通过自动分类、毒性特征描述和风险优先等级评价三级筛选程序筛选优先化学品。     

炼油废水中异养硝化-好氧反硝化菌的筛选

从炼油废水活性污泥中筛选出一株具有异养硝化-好氧反硝化能力的菌株WY6。对筛选菌株进行了生理生化实验和菌种鉴定,考察了碳源种类、培养基的m(C)∶m(N)、培养温度、初始p H及接种量对菌株硝化性能的影响;并对其NH3-N去除性能进行了考察。经鉴定,该菌为鲍曼不动杆菌,适宜的培养条件为:以丁二酸钠为碳源、培养温度30℃、初始p H 9.0、m(C)∶m(N)=10、接种量2.0%。在此条件下培养20 h,可将NH3-N质量浓度由245.46 mg/L降至9.71 mg/L,平均NH3-N去除速率为11.79 mg/(L·h)。WY6菌可在32 h内将实际炼油废水的NH3-N质量浓度由初始时的73.74 mg/L降至1.15 mg/L,NH3-N去除率达98.4%,表现出良好的应用前景。     

萘降解菌的筛选及其对多环芳烃的降解

从柴油污染土壤中筛选分离出一株萘降解菌N-3,进行了菌种鉴定及萘双加氧酶基因(nah)验证,并考察了该菌对不同种类多环芳烃(PAHs)的降解能力及降解过程中脱氢酶活性的变化。实验结果表明:该菌为铜绿假单胞菌(Pseudomonas aeruginosa),含有nah基因;当分别对液体培养基中质量浓度为50 mg/L的萘、菲、蒽、芘、芴降解84 h时,菌株N-3对萘、菲、蒽、芘、芴的降解率分别为28.81%,34.83%,36.65%,27.50%,23.47%。菌株N-3的脱氢酶活性与其对不同PAHs的降解率呈一定的正相关性。该菌不仅能有效降解萘,且对其他种类PAHs也有一定降解作用。     

一株吡啶降解菌的筛选及其降解性能

以吡啶为唯一碳源,从焦化厂活性污泥中分离得到一株对吡啶具有高效降解能力的菌株B1,对其进行了菌种鉴定。通过单因素实验研究了菌株B1适宜的降解条件,对反应过程进行了动力学拟合,并考察了菌株B1对焦化废水中吡啶的降解效果。实验结果表明:菌株B1为革兰氏阴性菌,属于不动杆菌属(Acinetobacter sp.);菌株B1适宜的降解条件为降解温度30℃、初始pH为7、摇床转速150 r/min;菌株B1对吡啶的降解过程符合零级反应动力学模型,当初始吡啶质量浓度为300 mg/L时,降解速率常数最高达到21.103 mg/(L·h);用菌株B1对初始吡啶质量浓度为430 mg/L的实际焦化废水处理74 h后,吡啶降解率可达74.26%。     

产表面活性剂菌筛选及其对柴油降解影响研究

运用微生物培养方法,从饭店排污口污泥中筛选了7株产表面活性剂菌株。为了研究产表面活性剂菌在柴油降解过程中所产生的影响,分别将这些菌株与柴油降解菌(实验室提取的另一株假单胞菌)共同作用,其中一株(B_(26))不但可以将降解诱导期从6 d缩短至4 d,而且能将降解率由原来的71.1%提高至80.6%,具有较大的研究价值。实验着重对B_(26)的作用机理、柴油降解的影响因素等进行了分析研究。经形态学和生理生化实验鉴定,B_(26)属于芽孢菌属,其代谢过程中产生脂肽类表面活性剂,利用冷冻干燥法提取生物表面活性剂产量为1.57 g/L。     

高效联苯降解菌的筛选及其特性

焦化废水属高浓度难降解工业有机废水,其中所含的多环芳烃属难降解有机物,且对环境产生毒害作用。为探索生物强化技术去除焦化废水中多环芳烃类化合物,采用选择性培养和多级富集的方法,以联苯为模型化合物,并作为惟一碳源,从焦化厂废水和污泥中分离和筛选得到6株联苯降解菌。通过逐渐提高底物浓度的方法驯化菌株后,从中筛选出降解效率最高的联苯降解菌株WIS-01,在此基础上进行菌属鉴定、细菌生长情况及联苯降解性能的研究。实验结果表明,3 d内菌株WIS-01对联苯的降解率可达99%以上,可耐受联苯的最高质量浓度为2 g/L。通过形态学、生理生化鉴定和16S rDNA序列比对分析,确定菌株WIS-01属于假单胞菌属,同源性达95%,命名为Pseudomonas sp.WIS-01。     

Multivariate toxicity profiles and QSAR modeling of non-dioxin-like PCBs--an investigation of in vitro screening data from ultra-pure congeners

The non-dioxin-like PCBs (NDL-PCBs) found in food and human samples have a complex spectrum of adverse effects, but lack a detailed risk assessment. The toxicity profiles of 21 carefully selected PCBs (19 NDL-PCBs) were identified by in vitro screening in 17 different assays on specific endpoints related to neurotoxicity, endocrine disruption and tumor promotion. To ensure that the test results were not affected by polychlorinated dioxins, dibenzofurans or DL-PCB contaminants, the NDL-PCB congeners were thoroughly purified before testing. Principal component analysis (PCA) was used to derive general toxicity profiles from the in vitro screening data. The toxicity profiles indicated different structure-activity relationships (SAR) and distinct mechanisms of action. The analysis also indicated that the NDL-PCBs could be divided into two groups. The first group included generally smaller, ortho-substituted congeners, comprising PCB 28, 47, 51, 52, 53, 95, 100, 101, 104 and 136, with PCB 95, 101 and 136 as generally being most active. The second group comprising PCB 19, 74, 118, 122, 128, 138, 153, 170, 180 and 190 had lower biological activity in many of the assays, except for three endocrine-related assays. The most abundant congeners, PCB 138, 153, 170, 180 and 190, cluster in the second group, and thereby show similar SAR. Two quantitative structure-activity relationship (QSAR) models could be developed that added information to the SAR and could aid in risk assessments of NDL-PCBs. The QSAR models predicted a number of congeners as active and among these e.g., PCB 18, 25, 45 and 49 have been found in food or human samples.     

微生物絮凝剂产生菌的筛选及其絮凝除浊性能

采用某污水处理厂活性污泥富集的菌种 ,通过筛选获得了 1 0株絮凝除浊性能较强的菌株。以其中絮凝性能最优的菌株GS7为研究对象 ,探讨了影响其絮凝作用的主要因素。结果表明 ,GS7的最适生长条件为 :培养基pH值 6、培养时间 1 8h、培养温度 30℃。当废水pH值为 8左右时 ,GS7的絮凝效果最好。在废水中投加少量的二价金属离子Ca2 +可大大提高GS7的絮凝除浊率。GS7处理城市河涌污水等实际废水时浊度去除率可达 93.5%。     

Estimating the number of active and successful bald eagle nests:an application of the dual frame method

Monitoring the number of animals in a wildlife population is an important task. In this paper, we estimate the number of active and successful bald eagle nests in a specific region using dual frame sampling techniques. The dual frame method combines independent samples from an incomplete list frame and an area frame that is assumed to be complete. Hartley's screening estimator is used to combine sample information from both frames. This methodology will be useful for monitoring any wildlife population where the breeding individuals have highly visible nesting territories which tend to be stable over many years.     

（R）—酮基布洛芬乙酯对映选择性水解酶产生菌的筛选及其特性

以酮洛芬乙酯为唯一碳源,经过两轮富集培养从土壤中分离得到45株优先生成（S）-酮洛芬和25株优先生成（R）-酮洛芬的菌株,其中产物对映体过量值高于85%的分别有13株和9株。在25株优先选择（R）构型的菌株中,G13号菌的活性较高而且选择性最好,对G13号菌的培养和催化特性研究表明：在培养基中添加吐温-80可以显著提高细菌的催化活力;静息细胞的最适反应温度为40℃,最适pH范围为7.0-8.0,在具有档板和磁力搅拌的三角板中,用G13号菌的静息细胞水解酮洛芬乙酯（50mmol/L）,68h的转化率为33.7%,产物（R）-酮洛芬的对映体过量值达到93%。