化学-生物絮凝污水处理工艺中微生物群落结构变化分析

利用分子生物学技术，直接从化学-生物絮凝工艺的活性污泥样品中提取DNA，对16S rDNA V3区进行PCR扩增，结合DGGE（变性浓度梯度凝胶电泳），分析了活性污泥中微生物群落结构，并对Shannon多样性指数进行分析讨论，通过研究指出系统中细菌数量的增加或减少．测定了活性污泥中部分菌种的16S rDNA V3区片段序列，通过NCBI（美国国立生物技术信息中心）基因库比对，初步确定细菌的属．结果表明，PCR—DGGE结合测序技术是一种完全可行的快速进行环境样品微生物研究的分析方法．图3表4参13     

稀有鮈鲫Dmrt基因家族13个成员的克隆与序列分析

已经发现果蝇Doublesex、线虫Mab-3、青DMRT1Y/DMY和人类DMRT1等性别决定与分化基因均含有一个具有DNA结合能力的保守基序--DM结构域,对性别决定和性别分化具有调控功能.利用简并PCR,从稀有鲫基因组DNA中克隆了13个具有不同DM结构域的Dmrt基因家族成员.基于DM保守基序,建立了各物种的进化树.结果表明,稀有鲫基因组存在多个Dmrt基因成员,该基因在脊椎动物和非脊椎动物中具有高度保守性,是一种理想的环境内分泌干扰物研究的分子模型,在分子生态毒理学研究中具有很好的应用前景.     

基于分子信标探针的荧光定量PCR方法检测转基因食品

选择了内源基因大豆植物凝集素(lectin)、玉米转化酶(invertase)和外源基因花椰菜花叶病毒35S(CaMV35S)启动子的分子信标探针,确定了探针浓度和镁离子浓度等反应条件,分别对转基因大豆和转基因玉米系列标准品进行内源基因和外源基因的荧光PCR扩增,在PCR反应过程中分别以两种荧光通道信号分别追踪同一样品DNA内源基因和外源基因的扩增动力学变化,并依此绘制了循环阈值与转基因食品百分比含量之间的标准曲线,建立了转基因大豆和转基因玉米的分子信标探针-荧光定量PCR检测方法,该方法具有特异性强、敏感性高的特点,实现了对转基因食品的定量分析.图7表1参11     

Analysis of parental strain DNA fragments existing in GEMs-Fhhh

There were 6 target DNA fragments of the three parental strains existing in the cell of GEMs( genetically engineered microorganism strain) Fhhh measured in this research by PCR(polymerase chain reaction). The determination showed that GEMs Fhhh contained all the 6 target DNA fragments, mnpl, mnp2, lipl, lip2, FLOI and 16S rDNA, and had the molecular genetic stability. Meanwhile the PCR production of each parental strain could only had its target DNA fragments and was different from each other. It may illustrate that the technique of the inter-kingdom protoplast fusion for the construction of GEMs Fhhh through the process of intercellular gene recombination could be used as a reliable bioengineefing technique to create the soecific functional stain for the nollution control.     

Isolation of fetal cells from transcervical samples by micromanipulation: Molecular confirmation of their fetal origin and diagnosis of fetal aneuploidy

Transcervical cell (TCC) samples have been shown to contain fetal cells amenable to molecular analysis. However, the presence of ‘contaminating’ maternal cells limits their use for prenatal diagnoses. In this report we show that clumps of fetal cells can be isolated from transcervical samples by micromanipulation and tested by fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR). Out of 129 clumps, isolated from mucus aspirates and transcervical lavages from 29 patients, 29 clumps from 11 patients were found to be exclusively of fetal origin as judged by the detection of chromosome 21-specific polymorphic DNA markers and Y-derived DNA sequences by PCR and FISH. One case of a male triploid fetus, diagnosed by the analysis of TCC samples obtained by mucus aspiration and lavage, was confirmed by testing clumps of cells isolated by micromanipulation.     

PCR-RFLP技术在环境地球化学研究中的应用及展望

PCR—RFLP技术为环境地球化学提供了一种新的研究方法和实验设计的新的思维方式。该方法具有所需样品量低、快速简便及特征性强等优点 ,可广泛应用于物质的生物地球化学循环、环境过程的生物作用、生物多样性及有机物源判断等方面的研究。利用PCR—RFLP技术 ,以环境中存在的 16SrRNA为对象 ,对环境生物的研究已广泛开展并取得了许多成果。展望未来研究成果 ,将会在海洋及湖泊沉积物等自然环境中发现更多的、新的微生物种类 ;将进一步阐明生物作用和物质循环的机理和过程 ;进一步阐明自然环境中生物大分子的变化机理及其环境效应并找到判断沉积物有机物源的新方法     

Repeated batch and continuous degradation of chlorpyrifos by Pseudomonas putida

The present study was undertaken with the objective of studying repeated batch and continuous degradation of chlorpyrifos (O,O-diethyl O-3,5,6-trichloropyridin-2-yl phosphorothioate) using Ca-alginate immobilized cells of Pseudomonas putida isolated from an agricultural soil, and to study the genes and enzymes involved in degradation. The study was carried out to reduce the toxicity of chlorpyrifos by degrading it to less toxic metabolites. Long-term stability of pesticide degradation was studied during repeated batch degradation of chlorpyrifos, which was carried out over a period of 50 days. Immobilized cells were able to show 65% degradation of chlorpyrifos at the end of the 50th cycle with a cell leakage of 112 × 10³ cfu mL^?1. During continuous treatment, 100% degradation was observed at 100 mL h^?1 flow rate with 2% chlorpyrifos, and with 10% concentration of chlorpyrifos 98% and 80% degradation was recorded at 20 mL h^?1 and 100 mL h^?1 flow rate respectively. The products of degradation detected by liquid chromatography–mass spectrometry analysis were 3,5,6-trichloro-2-pyridinol and chlorpyrifos oxon. Plasmid curing experiments with ethidium bromide indicated that genes responsible for the degradation of chlorpyrifos are present on the chromosome and not on the plasmid. The results of Polymerase chain reaction indicate that a ~890-bp product expected for mpd gene was present in Ps. putida. Enzymatic degradation studies indicated that the enzymes involved in the degradation of chlorpyrifos are membrane-bound. The study indicates that immobilized cells of Ps. putida have the potential to be used in bioremediation of water contaminated with chlorpyrifos.     

Data fusion modeling for groundwater systems

Engineering projects involving hydrogeology are faced with uncertainties because the earth is heterogeneous, and typical data sets are fragmented and disparate. In theory, predictions provided by computer simulations using calibrated models constrained by geological boundaries provide answers to support management decisions, and geostatistical methods quantify safety margins. In practice, current methods are limited by the data types and models that can be included, computational demands, or simplifying assumptions. Data Fusion Modeling (DFM) removes many of the limitations and is capable of providing data integration and model calibration with quantified uncertainty for a variety of hydrological, geological, and geophysical data types and models. The benefits of DFM for waste management, water supply, and geotechnical applications are savings in time and cost through the ability to produce visual models that fill in missing data and predictive numerical models to aid management optimization. DFM has the ability to update field-scale models in real time using PC or workstation systems and is ideally suited for parallel processing implementation. DFM is a spatial state estimation and system identification methodology that uses three sources of information: measured data, physical laws, and statistical models for uncertainty in spatial heterogeneities. What is new in DFM is the solution of the causality problem in the data assimilation Kalman filter methods to achieve computational practicality. The Kalman filter is generalized by introducing information filter methods due to Bierman coupled with a Markov random field representation for spatial variation. A Bayesian penalty function is implemented with Gauss–Newton methods. This leads to a computational problem similar to numerical simulation of the partial differential equations (PDEs) of groundwater. In fact, extensions of PDE solver ideas to break down computations over space form the computational heart of DFM. State estimates and uncertainties can be computed for heterogeneous hydraulic conductivity fields in multiple geological layers from the usually sparse hydraulic conductivity data and the often more plentiful head data. Further, a system identification theory has been derived based on statistical likelihood principles. A maximum likelihood theory is provided to estimate statistical parameters such as Markov model parameters that determine the geostatistical variogram. Field-scale application of DFM at the DOE Savannah River Site is presented and compared with manual calibration. DFM calibration runs converge in less than 1 h on a Pentium Pro PC for a 3D model with more than 15,000 nodes. Run time is approximately linear with the number of nodes. Furthermore, conditional simulation is used to quantify the statistical variability in model predictions such as contaminant breakthrough curves.