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1.
苏云金芽胞杆菌菌株WB9编码活性因子的基因分析   总被引:2,自引:3,他引:2  
采用PCR—RFLP及PCR技术对苏云金芽胞杆菌新分离菌株WB9的ICP、VIP、几丁质酶和肠毒素4种活性因子的编码基因进行了分析.结果表明,该菌株含有编码ICP的cry1Aa、cry1Ab、cry1Cb、cry1Fa和cry1GaS个cry1基因型,编码Vip3A蛋白的vip3A基因以及编码3种肠毒素的hblA、bceT和entS基因;不含编码几丁质酶的基因.将vip3A、hblA、bceT和entS基因PCR产物回收纯化后直接测序,经在线的BLAST软件进行同源性分析,前两个基因片段与Bt已公布基因序列的相应片段同源性分别为99%和96%~98%,bceT基因片段与蜡质芽孢杆菌bceT相应片段同源性为97%.  相似文献   

2.
几株光合细菌的表型特征及DNA-NDA同源性分析   总被引:4,自引:1,他引:4  
对5株新分离的光合细菌从形态、生理生化及DNA-DNA同源性等方面进行了研究.结果表明,菌株8与深红红螺菌(Phodospirillumrubrum)的模式菌株ATCC11170的DNA-DNA同源性为97%,菌株37与沼泽红假单胞菌(Rhodopseudomonaspalustris)的模式菌株ATCC17001的DNA-DNA同源性为80%;菌株55与球形红杆菌(Rhodobactersphaeroides)的模式菌株ATCC17023的DNA-DNA同源性为71%;菌株40和52分别为另外两个DNA同源群.根据各菌株形态、生理生化等表型特征以及DNAG+Cmol%和DNA-DNA同源性分析结果,确定了几株光合细菌的分类地位.  相似文献   

3.
有机肥中4类典型兽药抗生素的多残留测定   总被引:4,自引:0,他引:4  
建立了固相萃取-超高效液相色谱-串联质谱(SPE—UPLC—MS/MS)法同时测定有机肥中7种磺胺类、4种氟喹诺酮类、4种四环素类和3种大环内酯类抗生素残留的方法。采用乙腈和磷酸盐缓冲液(pH=3)的混合液作为有机肥样品的提取溶液,用强阴离子交换柱(SAX)-亲水亲脂平衡萃取柱(HLB)串联进行提取液的富集和纯化。以甲醇-φ=0.1%的甲酸溶液作为流动相,进行液相质谱分析。18种抗生素在5—500μg·kg-1的浓度范围内线性关系良好,决定系数(r2)1〉0.99。以3倍信噪比估算磺胺类、氟喹诺酮类、四环素类和大环内酯类的检测限分别为0.37~4.65、0.43—2.42、0.94~2.78和0.83~4.20μg·kg-1,这4类抗生素50和500μg·kg。2个添加水平的样品平均加标回收率分别为71.6%~94.3%、72.3%~86.7%、71.0%~102.2%和70.7%~93.3%,相对标准偏差在2.1%~11.4%之间。采用所建方法对南京地区市售8种有机肥中18种抗生素含量的测定结果显示,除磺胺类外,其他抗生素均有不同程度的检出。  相似文献   

4.
设置0、0.001、0.01、0.1、l和10mg·L-16个质量浓度梯度,测定了草甘膦异丙胺盐(Glyphosate—isopropylammonium)农药对球形棕囊藻(Phaeocystis globosa)生长、叶绿素a含量、SOD和CAT活性的影响,探讨了有机磷农药对球形棕囊藻的毒物刺激效应。结果表明,低浓度的草甘膦异丙胺盐对球形棕囊藻的生长呈现出刺激效应。在实验所设定的6个质量浓度梯度范围内,0.001mg·L0和0.01mg·L-1质量浓度处理下的刺激效应最为显著。该两个质量浓度处理下,球形棕囊藻的平均相对增长率比对照分别提高了1.27%和0.45%,叶绿素a含量分别比对照提高了9.2%和2.5%,SOD活性提高了5.9%和7.2%,CAT活性提高了93%和155%;而当草甘膦异丙胺盐质量浓度在0.1mg·L-1以上时,球形棕囊藻的生长率、叶绿素a含量、SOD活性均显著低于对照。草甘膦异丙胺盐在0.001mg·L-1和0.01mg·L-1范围内对球形棕囊藻均呈现刺激效应,而高于0.1mg·L-1时球形棕囊藻各生理指标表现出显著抑制效应。研究结果为了解有机磷农药对海洋微藻生长的影响特征,揭示有机磷农药对微藻产生低促高抑的规律和为深入探索赤潮暴发的成因提供依据。  相似文献   

5.
为了研究高寒区植物生长过程对主要全球气候变化因子[如环境CO2浓度加倍(EC)、环境温度升高(ET)]及其二者组合(ECT)条件下的响应和适应,在青藏高原东缘岷江上游中部的中国科学院成都生物研究所茂县生态站[A(E)103^o53’,φ(N)31^o41’,海拔1820m]建立了一组全封闭的生长室系统.系统由6个独立、自控、封闭的生长室和2个对照组成.本文首先描述了生长室系统的结构和控制原理,然后基于2004年的运行结果,分析了系统的各项指标特征.结果表明:(1)EC和ECT生长室内的CO2浓度在650~800μmol mol^-1之间的时间分别占91.32%和91.67%(目标CO2浓度=环境CO2浓度加倍);(2)ET和ECT生长室内空气温度升高1.0~3.5℃的时间分别占95.06%和88.73%(目标温度=现行环境温度+2℃);(3)生长室内太阳辐射和光合有效辐射强度减少20%~40%的时间分别占90.42%和89.43%.生长室系统能够提供多种与自然环境变量较一致的环境条件,也能提供长期的、稳定的目标环境变量.是研究高寒区植物生长过程对全球气候变化响应和适廊的有效模拟实验系统.  相似文献   

6.
青岛东风盐场中极端嗜盐古细菌的特性   总被引:3,自引:0,他引:3  
从青岛东风盐场分离到3株嗜盐古细菌(编号:ZDA-1,ZDA-2和ZDA-5),细胞为多形态杆状(0.7~15μm×2.0~50μm),最适生长NaCl浓度为3.4mol/L,含有甘油二醚脂,类胡萝卜素色素和极性脂TGD-2(三糖基二醚脂),x(C+C)分别为63.7%,62.7%,和64.3%,据此,这3株菌可归入嗜盐小盒苗属(Hchoarcula);但它们不水解淀粉,明胶不液化,不水解酪蛋白等生理生化特性不同于该属中现已正式承认的两个种,因此,本工作分离的3株菌可能是嗜盐小盒菌属一个新种.  相似文献   

7.
从巴丹吉林沙漠盐湖表层沉积物中筛选到一株高效耐盐苯酚降解菌CL.测定了菌株CL的生理生化指标、16S rRNA基因序列,通过动力学模型探究了该菌株的生长和苯酚降解特性,同时考察了固定化对其耐受及降解苯酚能力的影响.结果表明,菌株CL属于葡萄球菌属(Staphylococcus sp.),在温度30℃、pH 7.0—8.0、盐度0—10%和苯酚浓度100—200 mg·L~(-1)条件下,该菌株能高效降解苯酚,其降解率均在85%以上.菌株CL对不同浓度苯酚的降解符合Haldane模型,其最大比降解速率和抑制常数分别为0.32 h~(-1)和351.70 mg·L~(-1),同时该菌株在不同盐度下对苯酚的降解符合Ghose and Tyagi模型.固定化可以明显增加菌株CL对苯酚的降解和耐受能力.菌株CL在高盐环境下能够高效降解苯酚,具有生物处理高盐含酚废水的潜力.  相似文献   

8.
假单胞菌(Pseudomonas)ND6菌株的萘降解基因位于102kb的质粒pND6-1上。以pUC18质粒为载体,制备了含有1.5-3.0kbpND6-1DNA随机片段的基因文库。通过DNA测序和DNA序列的同源性分析,从基因文库中筛选出含有萘趋化基因nahY的克隆。NahY基因的大小为1617bp,编码的萘趋化蛋白由538个氨基酸组成,与假单胞菌G7菌株的nahY基因相比,核苷酸序列的同源性是96.7%,编码的氨基酸序列的同源性是95%。图4参7  相似文献   

9.
紫外光B辐射对水稻生长和生长素水平影响的初步研究   总被引:5,自引:0,他引:5  
2个水稻品种IR68和Dular生长在室外条件下,在以自然条件、13.0和19.1kJ·m-2.d-1(分别模拟臭氧浓度下降20%和40%时的UV-B强度)的紫外光B(UV-B280~320um)进行2和4wk的照射处理,以研究UV-B对水稻生长的影响.结果表明:UV-B强度增加能使2个水稻品种的株高、叶面积和叶m(DW)下降,而对分蘖数没有影响;随着UV-B处理强度的增加,IR68和Dular叶片IAA含量显著下降.在4wk处理的条件下.19.1kJ·m-2·d-1的UV-B使IR68和Dular叶片的IAA含量分别下降了48.7%和46.2%.值得注意的是.UV-B处理提高了2个水稻品种叶片内的IAA氧化酶的活性.初步推测UV-B使水稻叶片IAA氧化酶活性提高导致IAA含量的下降.从而抑制了水稻的生长.  相似文献   

10.
高温原油降解菌处理油田采油废水的研究   总被引:3,自引:0,他引:3  
研究了筛选的嗜热降解功能菌对高温、高盐环境的耐受性,同时采用接触氧化工艺,探索高温条件下嗜热生物系统对油田外排水的处理效果.结果表明,嗜热降解功能菌能够耐受高温(40~59℃)、高盐(30g/kg)和高pH(9.0)环境,实验室小试运行温度55~60℃,进水CODcr为270~510mg/L,出水CODcr为61.7~101.0mg/L.胜利油田王家岗污水站高温外排水生物处理中试,进水CODcr200~300mg/L,温度60~67℃,生化出水CODcr79.2~140.1mg/L.图4表3参10  相似文献   

11.
基因污染与生态环境安全   总被引:6,自引:0,他引:6  
论述了基因污染可能对生态环境安全造成的影响。转基因作物有可能污染天然物种的基因库;有可能破坏传统农作物品种的遗传多样性,加速作物种植品种的单一化及基因资源的流失;使抗除草剂作物的基因向野生或半野生植物漂移的可能性加大,有可能创造出“超级杂草”;带有病毒型转基因作物的基因重组,有可能创造出新的植物病毒,导致新的病害;BT转基因抗虫作物分泌的毒素,在食物链中传递,很难加以控制,对非目标生物造成危害,并最终破坏自然生态系统的平衡。文章还从不同角度分析了基因污染的严重性。  相似文献   

12.
土肥的基础地位是不随社会性质或社会经济类型的变化而变化的,它既具重要性,又具长久性.市场经济是仍然需要土肥科技的.土肥科技的教学、科研和推广的力度必须加大,局面必须改观,且宜快不宜迟.土肥科技工作者一定要将培肥地力作为中心工作.根据广东的实际,增施有机肥是培肥地力的主要措施,因而抓秸秆还田和发展冬绿肥是我们工作的重点.  相似文献   

13.
Indoor and outdoor air pollution is known to contribute to increased lung cancer incidence. This study is the first to address the contribution of home heating fuel and geographical course particulate matter (PM10) concentrations to lung cancer rates in New Hampshire, USA. First, Pearson correlation analysis and geographically weighted regression were used to investigate spatial relationships between outdoor PM10 and lung cancer rates. While the aforementioned analyses did not indicate a significant contribution of PM10 to lung cancer in the state, there was a trend towards a significant association in the northern and southwestern regions of the state. Second, case-control data were used to estimate the contributions of indoor pollution and secondhand smoke to the risk of lung cancer with adjustment for confounders. Increased risk was found among those who used wood or coal to heat their homes for more than 10 winters before the age of 18, with a significant increase in risk per winter. Resulting data suggest that further investigation of the relationship between heating-related air pollution levels and lung cancer risk is needed.  相似文献   

14.
High concentrations of metals (cadmium, copper, lead, and zinc) and of lindane were measured in the sediment and in the spawn and tadpoles of Bufo bufo, Rana dalmatina, and Rana ridibunda from two Austrian locations. Residues in spawn suggest maternal transfer. Increase of the metal concentrations from spawn to advanced tadpole stage is explained by the larval microphaguous feeding habits which cause high exposition of the tadpoles to substances concentrating in sediments and suspended particles. Metal and pesticide concentrations in spawn and tadpoles are toxic to various other aquatic organisms and are furthermore considered to be potentially hazardous to the anurans themselves. The results are conform with world‐wide observations of contamination of anuran larvae with heavy metals, and prove the significance of non‐point source chemical exposure due to allochthonous toxicant input by wind load and precipitation.  相似文献   

15.
● Adsorption of PFASs on MPs and its mechanisms are critically reviewed. ● MPs could alter the transport and transformation of PFASs in aquatic environments. ● Combined toxicity of MPs and PFASs at organismal and molecular levels is discussed. Microplastics (MPs) are recognized as vectors for the transport of organic contaminants in aquatic environments in addition to their own adverse effects on aquatic organisms. Per- and polyfluoroalkyl substances (PFASs) are widely present in aquatic environments due to their widespread applications, and thus coexist with MPs. Therefore, we focus on the interaction of MPs and PFASs and related combined toxicity in aquatic environments in this work. The adsorption of PFASs on MPs is critically reviewed, and new mechanisms such as halogen bonding, π-π interaction, cation-π interactions, and micelle formation are proposed. Moreover, the effect of MPs on the transport and transformation of PFASs in aquatic environments is discussed. Based on four typical aquatic organisms (shellfish, Daphnia, algae, and fish), the toxicity of MPs and/or PFASs at the organismal or molecular levels is also evaluated and summarized. Finally, challenges and research perspectives are proposed, and the roles of the shapes and aging process of MPs on PFAS biogeochemical processes and toxicity, especially on PFAS substitutes, are recommended for further investigation. This review provides a better understanding of the interactions and toxic effects of coexisting MPs and PFASs in aquatic environments.  相似文献   

16.
Recent extinctions often resulted from humans retaliating against wildlife that threatened people's interests or were perceived to threaten current or future interests. Today's subfield of human-wildlife conflict and coexistence (HWCC) grew out of an original anthropocentric concern with such real or perceived threats and then, starting in the mid-1990s, with protecting valued species from people. Recent work in ethics and law has shifted priorities toward coexistence between people and wild animals. To spur scientific progress and more effective practice, we examined 4 widespread assumptions about HWCC that need to be tested rigorously: scientists are neutral and objective about HWCC; current participatory, consensus-based decisions provide just and fair means to overcome challenges in HWCC; wildlife threats to human interests are getting worse; and wildlife damage to human interests is additive to other sources of damage. The first 2 assumptions are clearly testable, but if they are entangled can become a wicked problem and may need debunking as myths if they cannot be disentangled. Some assumptions have seldom or never been tested and those that have been tested appear dubious, yet the use of the assumptions continues in the practice and scholarship of HWCC. We call for tests of assumptions and debunking of myths in the scholarship of HWCC. Adherence to the principles of scientific integrity and application of standards of evidence can help advance our call. We also call for practitioners and interest groups to improve the constitutive process prior to decision making about wildlife. We predict these steps will hasten scientific progress toward evidence-based interventions and improve the fairness, ethics, and legality of coexistence strategies.  相似文献   

17.
湿解产物与堆肥在土壤中的稳定性和腐熟度比较分析   总被引:1,自引:1,他引:1  
研究了不同培养阶段湿解产物与土壤混合物(HTS)的物质变化特征、稳定性和腐熟度,并与堆肥和土壤混合物(CS)及自然土壤进行了对比。结果表明:在培养过程中,所有HTS和CS的参数变化趋势相似,HTS的温度变化接近于CS的温度变化,稍高于自然土壤的温度,低于环境温度;pH值变化不大,基本稳定在7.6左右;在培养初期,水溶性有机碳比有机态氮w(WSC)/w(Norg)小于0.55,种子发芽系数(GI)高于80%;培养14d后,w(C)/w(N)降低至小于20,w(NH4 -N)/w(NO3--N)渐渐趋于稳定至小于0.16,GI基本高于100%;49d后,HTS的CO2释放率接近CS和自然土壤的CO2释放率;种子发芽系数的变化表明,湿解产物中含有更丰富的营养元素,可以促进植物根系的生长;相关性分析显示,w(WSC)/w(Norg)、w(NH4 -N)/w(NO3--N)和GI可以作为湿解产物腐熟度的评价指标。综合各项参数表明,湿解产物在土壤中会很快达到稳定,可以安全应用。  相似文献   

18.
水循环经济与水资源合理开发利用研究   总被引:6,自引:1,他引:6  
马忠玉  蒋洪强 《生态环境》2006,15(2):416-423
在分析水循环经济的概念和基本特征、回顾国内外水循环经济与水资源合理开发利用历史演进和研究进程的基础上,陈述了可持续发展理论、物质代谢理论和产业生态学理论是水循环经济研究的三大新理论支柱。从现代水资源合理开发利用研究必须从系统定量的角度研究水资源系统与水社会经济系统的整体行为、演化规律及其相互作用的角度,指出了物质流分析技术(MFA)与投入产出分析技术(I/O)是水循环经济研究的主流方法。分别阐明了水循环经济理论体系构建的研究、水循环经济技术创新问题的研究、水循环经济发展模式选择问题的研究、水循环经济管理体制及经济机制问题的研究是当前水循环经济研究的四项重点内容。  相似文献   

19.
河流底泥污染及其控制与修复   总被引:3,自引:0,他引:3  
水体底泥污染是世界范围内的一个环境问题。污染物通过大气沉降、废水排放、雨水淋溶与冲刷进入水体,最后沉积到底泥中并逐渐富集,使底泥受到严重污染。在河流环境中,河床沉积底泥以推移和悬浮形式输送,很大程度上导致了上覆水和沉积底泥的相互物理作用。河流有强有力的自然环境,在河流系统中趋向有利于沉积底泥的解吸作用,从而将会影响上覆水的水质。因此,在水质管理计划中,应该将已污染的沉积底泥作为一个污染源予以考虑,沉积底泥是河流污染的一个重要方面。文章根据近年来国内外对河流底泥污染的控制、处理、修复及利用的文献资料,分析了河流底泥的污染现状及主要类型,包括重金属、NP营养物质、难降解有机物和持久性有毒污染物等,指出了目前在底泥污染修复中存在的问题。针对河流底泥污染控制与修复技术,介绍了除控制外源污染物外的物理修复、化学修复和生物修复等几种主要的修复方法和技术,分析了各种方法的利弊以及适用情况。在阐述了堆肥、建材利用、低温热解、湿地及栖息地建设、修复废弃地和建设填方等利用方式后,提出具体的控制和修复应因地制宜,综合各种恢复技术及利用方式,以达到控制及修复污染的河流底泥,恢复河流生态系统之目的。  相似文献   

20.
Growth and pollution convergence: Theory and evidence   总被引:3,自引:0,他引:3  
Stabilizing pollution levels in the long run is a pre-requisite for sustainable growth. We develop a neoclassical growth model with endogenous emission reduction predicting that, along optimal sustainable paths, pollution growth rates are (i) positively related to output growth (scale effect) and (ii) negatively related to emission levels (defensive effect). This dynamic law reduces to a convergence equation that is empirically tested for two major and regulated air pollutants – sulfur oxides and nitrogen oxides – with a panel of 25 European countries spanning the years 1980–2005. Traditional parametric models are rejected by the data. More flexible regression techniques confirm the existence of both the scale and the defensive effect, supporting the model predictions.  相似文献   

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