少动鞘氨醇单胞菌ZX4儿茶酚2,3-双加氧酶基因的克隆与表达

应用PCR方法克隆了少动鞘氨醇单胞菌(Sphingomonas paucimobilis)ZX4菌株的儿茶酚2,3-双加氧酶基因(c230-ZX4)。核苷酸序列测定与分析表明,该基因片段全长924 bp且具有一个完整的阅读框,编码306个氨基酸残基。该基因与已报道的来自菌株S.yanoikuyae B1和Sphingomonas sp.KMG425的xylE基因(编码产物均为C230)具有较高的核酸序列同源性,分别为94.37%和94.05%。通过HindⅢ和XhoⅠ两个限制性酶切位点将该基因连接到质粒pET30(a) 上得到重组表达质粒pET-S3,并在E.coli BL21进行了表达,得到了42.3 kD的融合蛋白。酶活测定发现该基因工程菌株的发酵产酶活力明显高于出发菌株。     

炔雌醇和菲2种环境内分泌干扰物对斑马鱼的影响研究进展

炔雌醇和菲在各种水环境中广泛分布,其对水生动物的繁殖、发育和生长等各方面有显著的影响.斑马鱼容易饲育,遗传学工具成熟,是研究脊椎动物的一种模式动物.综述了炔雌醇和菲2种内分泌干扰物对斑马鱼发育的影响及其机制的研究进展.     

菲、芘、壬基酚对黑褐新糠虾的急性毒性

通过测定菲、芘、壬基酚对黑褐新糠虾的急性毒性,探讨了这三种难降解有机物对黑褐新糠虾的24h、48 h、72 h和96 h半致死浓度(LC50 ).结果表明菲对黑褐新糠虾24 h、48 h、72 h和96 h的半致死浓度分别为530 μg/L、310 μg/L、166 μg/L和126 μg/L;壬基酚对黑褐新糠虾24 ...     

Preparation of Core-shell Magnetic Rosin-based Polymer Microspheres and Their Adsorption Kinetics and Thermodynamics of Mn2+北大核心CSCD

The core-shell magnetic rosin-based polymer microspheres Fe3O4@RPM were synthesized by chemical precipitation and suspension polymerization with maleic rosin ethylene glycol acrylate as cross-linking agent, methacrylic acid and methyl methacrylate as monomers, and Fe3O4 as a magnetic core. The preparation conditions were optimized. The structure of Fe3O4@RPM was characterized by Fourier transform infrared spectrometer(FT-IR), field emission scanning electron microscope (FESEM), X-ray diffraction instrument(XRD), and thermogravimetric analysis(TGA), and so on. The adsorption kinetics and thermodynamics for adsorbing Mn2+ were studied through static adsorption experiments. The results showed that the preparation conditions of the polymeric magnetic microspheres with phenanthrene framework were shaking at the speed of 400 r/min,adding 1 g azodiisobutyronitrile as initiator and reacting for 4 h at 70 ℃. The second-order kinetics model could well describe the adsorption process of Mn2+ in the experimental range of concentration and temperature, the adsorption thermodynamic studies showed that ΔH >0,ΔG <0,ΔS >0,which indicated that the adsorption was a spontaneous endothermic process. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

酶抑制剂对高羊茅代谢菲的影响

[目的]研究了酶抑制剂对高羊茅代谢多环芳烃的影响。[方法]选取不同浓度Vc和Na2SO3处理高羊茅。[结果]高浓度Vc和Na2SO3可以抑制高羊茅对菲的代谢,低浓度时,反而会促进高羊茅对菲的代谢。这可能是由于高浓度酶抑制剂处理中,植物的酶活不会再生,而低浓度酶抑制剂的处理中,植物的酶活会很快再生所致;并且相对于未使用酶抑制剂的对照植物,用低浓度抑制剂处理后,植物酶活会有所提高。[结论]为有效去除多环芳烃,降低其对生态安全和人类健康的危害提供科学依据。     

污染土壤中菲高效降解菌的筛选及其降解特性

运用恒温培养法研究了菲在不同土壤中的降解动态,结果表明未灭菌土壤中菲半衰期仅5.1d,而灭菌土壤中半衰期为前者4倍,可见土壤微生物发挥了重要作用;从试验土壤中分离到一株菲高效降解菌,经16SrDNA鉴定为产碱杆菌;优势菌最高可以耐受500mgL-1左右的菲,降解菲的最适温度25℃和pH为7,土壤接种优势菌后有助于加快菲的降解;从该优势菌中提取的粗酶液米氏常数为50.30nmolml-1,最大降解速率为171.33nmolmg-1min-1。     

蚯蚓活动对金发草修复土壤菲芘污染的强化作用

采用盆栽试验法,研究了蚯蚓(Pheretimasp.)对金发草(Pogonatherum paniceum L.)修复菲、芘污染土壤的强化作用。结果显示,在试验浓度范围(20.1~322.1 mg kg-1)内,蚯蚓活动促进了菲、芘污染土壤中金发草的生长,其根冠比明显增大。添加蚯蚓70d后,种植金发草的土壤中菲、芘的平均去除率高达77.0%、70.6%,平均去除率分别较无蚯蚓作用时(68.7%、61.2%)增长了8.3%、9.5%;相同污染水平下,蚯蚓活动对芘的强化去除程度总是大于菲。各修复因子中,植物-微生物交互作用对菲、芘去除的平均贡献率(46.6%、42.8%)最为突出,分别较无蚯蚓活动时(41.6%、36.6%)增长了5.0%、6.1%。说明蚯蚓活动可强化土壤-植物系统对土壤中菲、芘污染的去除作用。     

菲降解体系中细菌多样性的研究

[目的]探索生物多样性在污染物降解中的作用。[方法]以菲为唯一碳源,通过选择培养的方式,从采油废水处理的好氧污泥中富集了菲降解功能微生物类群,并利用PCR结合变性梯度凝胶电泳(DGGE)的方法对它的微生物组成特征进行分析。[结果]混合菌群在菲生物代谢过程中表现出较丰富的细菌多样性,混合菌群的菲降解能力显著高于已报道的纯培养体系。随着培养时间的延长,群落的丰度逐渐增加,群落相似性越来越高。DGGE对于表征一定系统中微生物群落的动态变化有较高的分辨率、方便、快捷,具有良好的应用前景。[结论]群落中多种不同微生物的协同作用可能是目标物高效降解的原因。     

玉米对土壤中菲芘修复作用的初步研究

采用系列浓度菲芘进行盆栽试验，研究玉米对污染土壤菲芘的去除效果与累积机理。结果显示，玉米对菲芘的去除效果明显，60d试验完成后，玉米生长的土壤中平均大约有69．8％-91．2％的菲与77．0％，88．4％的芘被去除，平均去除率分别比对照1（加叠氮化钠）高63．6％和72．3％；比对照2（无叠氮化钠）高15．1％与38．2％。玉米能明显地吸收与累积污染土壤中菲和芘，并随土壤菲芘含量的增加而增大。生物富集因子（BCFs）随着土壤菲芘含量的增加而减小，芘的生物富集因子大于菲，不同种类多环芳烃以及植物不同部位间BCFs差异较大，菲的叶片BCFs（0．79，2．45）大于茎（0．17—1．76），根BCFs（0．42—1．21）最小，芘处理时叶片和茎的BCFs分别是1．03，3．31与0．2，2．17，明显低于根BCFs（2．07—6．40）。玉米能够在高浓度多环芳烃污染土壤中正常生长，并且能累积与去除污染土壤中的菲和芘，表明用玉米修复多环芳烃污染土壤是一种可行的方法。     

Potential for biodegradation of anthropogenic organic compounds at low temperature in boreal soils

The effect of temperatures of −2.5 to +20 °C on the biodegradation of concentrations 0.2-50 μg cm⁻³ of pentachlorophenol (PCP), phenanthrene, pyrene and 2,4,5-trichlorophenol (TCP) was studied in soils sampled from an agricultural field and a relatively pristine forest in Helsinki, Finland. At the temperatures simulating seasonal variation of boreal soil temperatures [Heikinheimo, M., Fougstedt, B., 1992. Statistic of Soil Temperature in Finland. Meteorological Publications 22. Finnish Meteorological Institute, Helsinki, Finland], the response of mineralization of PCP, phenanthrene and 2,4,5-TCP was the most effective in the rhizosphere fraction of the forest humus soil at the substrate concentrations of ?5 μg cm⁻³. In the control incubation, performed at constant temperature of +20 °C, the mineralization yields of the model pollutants were highest in the agricultural soil with the highest applied substrate concentration (50 μg cm⁻³). The results suggest that the high level of pollutant mineralization at +20 °C resulted from the apparent adaptation of the soil microbial community to the high substrate concentration. No such adaptation occurred when the soils were incubated at temperatures simulating the actual boreal soil temperatures. The present results stress the role of adjusting the incubation conditions to environmentally relevant values, when assessing biodegradation of anthropogenic organic compound in boreal soils.