固体样品的荧光原位杂交方法

荧光原位杂交是一种新兴的分子细胞遗传学技术,广泛应用于各个学科,该文主要介绍了一种在环境微生物研究中可以广泛应用的对固体样品进行荧光原位杂交(FISH)的实验方法。     

寡聚核苷酸保护的银纳米簇的生成及其在生物成像中的应用

文中以寡聚核苷酸、硼氰化钠(NaBH4)、硝酸银(AgNO3)为原料合成了寡聚核苷酸保护的银纳米簇,将寡聚核苷酸保护的银纳米簇与细胞结合进行成像分析,并采用荧光光谱、MALDI TOF MS、TEM及LSCM对寡聚核苷酸保护的银纳米簇进行了测试分析。质谱测试结果表明,寡聚核苷酸保护的银纳米簇中含有10个银原子。投射电镜观察发现寡聚核苷酸保护的银纳米簇颗粒大小基本小于2 nm。荧光共聚焦的细胞成像结果发现寡聚核苷酸保护的银纳米簇能进入细胞并进行原位标记成像。细胞毒性试验表明该银纳米簇无毒性。     

稳定性同位素探针技术在土壤功能微生物原位鉴定的应用

新近发展起来的稳定性同位素探针技术(SIP)与分子生物学方法结合,能够定向发掘复杂环境中参与特定生态过程的微生物资源,是土壤功能微生物原位鉴定的有效手段,具有广阔的应用前景.其原理是环境样品中的功能微生物代谢同化同位素标记的底物,通过对其生物标志物(即DNA、RNA、PLFA等)进行提取、分离、鉴定和比对分析,以此获取介导土壤物质转化和循环过程的功能微生物的直接信息.本文在分别介绍SIP技术在土壤功能微生物原位鉴定过程中的各种前处理方法、生物标志物选择及后续鉴定方法的基础上,综述了SIP技术在研究驱动土壤有机污染物生物降解、碳氮循环等过程的功能微生物原位鉴定的应用进展,展望了SIP技术在土壤微生物基因组学方面的应用前景.     

原位杂交技术与细胞遗传图的构建

原位杂交是在分子生物学领域应用极为广泛的实验技术之一,本文对其最新研究进展进行综述.核酸原位杂交可根据其检测物而分为细胞内原位杂交和组织切片内原位杂交;根据其所用探针及所要检测核酸的不同又可分为DNA-DNA、RNA-DNA、RNA-RNA杂交.原位杂交的探针可以是同位素的探针,用放射自显影来检测;也可以是非同位素的探针,通过荧光或酶法予以检测.细胞遗传图综合了来自遗传图和细胞学图两方面的信息,它既能反映基因或DNA标记之间在染色体上的真实距离,又能显示它们与染色体的细胞学结构间确切的位置关系.构建植物细胞遗传图的宗旨是将遗传图上的诸多标记与其在染色体的具体位置联系起来,利用荧光原位杂交(FISH)直接把DNA序列定位到染色体上.     

SPE柱法测定畜产品中29种二■英及其类似物

利用加速溶剂萃取仪(ASE)萃取样品,酸性硅胶除脂,复合硅胶SPE和活性炭SPE快速柱净化分离畜产品样品中的二英(PCDD∕Fs)及其类似物(DL-PCBs),高分辨气相色谱-高分辨质谱(HRGC-HRMS)分析样品,建立了畜产品中29种PCDD∕Fs及DL-PCBs的HRGC-HRMS检测方法。结果显示:PCDD∕Fs和DL-PCBs的平均回收率为78.7%—109%,RSD≤10.2%,同位素内标的回收率为52.0%—116%,本方法能够应用于畜产品中二噁英类化合物的检测。     

土壤微生物多样性的研究方法

对土壤微生物多样性的研究方法进行了综述。其中,微生物平板记数法仅能简单反映样品中微生物的类型和数量;从生化方面研究微生物多样性的方法主要包括基于底物利用率的代谢图谱以及磷脂脂肪酸生物标记法;土壤微生物在基因水平上的多样性可以用PCR-DGGE和PCR-TGGE技术、单链构象多态性分析(SSCP)、限制性片段长度多态性(RFLP)和末端限制性片段长度多样性(T-RFLP)等进行研究。荧光原位杂交可通过寡核苷酸探针和全细胞杂交进行原位鉴定和计算单个微生物细胞。目前,基因芯片技术已在微生物检测和群落分析中获得了很大关注,而高通量测序技术使得对土壤微生物转录组和基因组进行全面分析成为可能。     

稳定同位素技术在林产品产地溯源和掺假鉴别中的应用研究进展

稳定同位素技术能够有效应用于林产品的产地溯源和掺假鉴别。利用碳、氢、氧、氮同位素技术,结合线性判别-主成分分析,能够较好地追溯中华猕猴桃Actinidia chinensis,樱桃Cerasus pseudocerasus,橄榄Canarium album油等林产品的产地;采用单一的同位素比例质谱,或者结合高效液相色谱、气相色谱,能够鉴别果汁饮料、保健品、香精香料的掺假;利用氮同位素能认证有机产品。基于国内外学者在林产品溯源、鉴别、有机产品认证等方面的研究工作,总结了稳定同位素技术的基本原理及其在林产品产地溯源和掺假鉴别中的应用研究进展,以期推动稳定同位素技术的更广泛应用,及完善中国林产品的检测技术并构建产品溯源体系。     

激光扫描共聚焦显微镜在植物研究中的应用

荧光成像技术、光学显微镜和计算机成像分析系统的完美结合催生了激光扫描共聚焦显微镜(LSCM)的出现,其优越的结构特点实现了将较厚样品能够逐点逐层扫描成清晰图像,有利于各种荧光信号的采集,直观进行三维重建和样品多重荧光信号采集进行的定量分析。这些优势功能极大地提高了从细胞、分子水平来探求生物时空表达基本功能的能力。本文详细阐述了近年来随着该项技术发展的日益多样化,激光扫描共聚焦显微镜技术在植物组织化学、植物细胞器和细胞骨架、植物发育方面的应用。     

荧光原位杂交技术在蔷薇属植物研究中的应用综述

荧光原位杂交(fluorescent in situ hybridization,FISH)技术是一种重要的非放射性原位杂交技术,具有试验周期短、灵敏度高、分辨率高、直观可见等优点。常规的荧光原位杂交方法已在很多植物中普遍应用,但对蔷薇属(Rosa L.)植物的研究较少,主要集中在45S rDNA和5S rDNA的基因定位与染色体同源性分析上。本文对蔷薇属植物的FISH研究进行总结和描述,并对其在蔷薇属植物分子细胞遗传学研究中的应用前景作了展望。     

荧光显微技术在土壤微生物可视化研究中的应用

对近年来荧光显微技术在土壤微生物可视化研究中的应用进行了综述,介绍了荧光显微镜技术、激光共聚焦技术、荧光原位杂交技术,并综合分析了各项技术的优缺点。     

Oxygen isotopic compositions of asteroidal materials returned from Itokawa by the Hayabusa mission

Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid.     

分子生态学技术应用于新疆环境微生物研究进展

对应用于环境微生物研究的分子生态学技术进行综述,并综述了近些年来新疆环境微生物研究的进展,最后,对新疆极端环境微生物研究前景进行了展望。     

Oxygen isotopes in refractory stratospheric dust particles: proof of extraterrestrial origin

The oxygen and magnesium isotopic compositions of five individual particles that were collected from the stratosphere and that bear refractory minerals were measured by secondary ion mass spectrometry. Four of the particles exhibit excesses of oxygen-16 similar to those observed in anhydrous mineral phases of carbonaceous chondrites and thus are extraterrestrial. The oxygen and magnesium isotopic abundances of one corundum-rich particle are consistent with a terrestrial origin. Magnesium in the four extraterrestrial particles is isotopically normal. It is unlikely that these particles are derived from carbonaceous chondrites and thus such particles probably represent a new type of collected extraterrestrial material.     

Phase separation of lipid membranes analyzed with high-resolution secondary ion mass spectrometry

Lateral variations in membrane composition are postulated to play a central role in many cellular events, but it has been difficult to probe membrane composition and organization on length scales of tens to hundreds of nanometers. We present a high-resolution imaging secondary ion mass spectrometry technique to reveal the lipid distribution within a phase-separated membrane with a lateral resolution of approximately 100 nanometers. Quantitative information about the chemical composition within small lipid domains was obtained with the use of isotopic labels to identify each molecular species. Composition variations were detected within some domains.     

The comparative analysis and identification of secondary metabolites between Tibet wild and cultivated pomegranates (Punica granatum L.) in China

Secondary metabolites are closely related to the nutritional quality and health functions of plants. We investigated the secondary metabolites of both wild (n=23) and cultivated (n=27) pomegranate plants (Punica granatum L.) growing in China. The total flavonoid (TF) and tannin (TT) contents from the peel and juice were determined and the secondary metabolites in the peel (ZLP) and juice (ZLZ) of ‘Zela 4’ were identified using liquid chromatography–electrospray ionization tandem mass spectrometry (LC–ESI-MS/MS). Analysis of variance (P<0.05) showed that there were significant differences in the TF content of peel (TF (P)) and juice (TF (J)), and the TT content of peel (TT (P)) and juice (TT (J)) among different pomegranate accessions. Pearson correlation analysis showed that latitude and altitude might be the main environmental factors affecting TF and TT contents in pomegranates. In this study, 279 secondary metabolites were identified in the ZLP and ZLZ. In addition, we report for the first time 227 secondary metabolites in pomegranates. Using orthogonal partial least squares discriminant analysis, 90 differential metabolites were identified in ZLP and ZLZ. In addition, we screened eight specific germplasms (high-TF (P), ‘Junyong 3’; low-TF (P), ‘Yanzhihong’; high-TF(J), ‘Zela 4’; low-TF (J), ‘Yudazi’, high-TT (P), ‘Junyong 4’; low-TT (P), ‘Anba 1’; high-TT(J), ‘Yeba 1’; and low-TT (J), ‘Baihuayushizi’). The results of our study provide a reference for the development and utilization of wild pomegranate resources and pomegranate breeding in China.     

水体重金属污染危害及治理技术

介绍了水体重金属污染的来源及其对生态环境中几类典型生物的危害情况,概述了现阶段应用较为典型的物理吸附、化学沉淀、离子交换、藻类及微生物治理等五种的水体重金属治理技术方案,分析了这五种水体重金属治理技术的优势和缺陷,汇总了不同场景重金属污染水体的治理建议和以及适用的环境,为水环境治理修复人员提供更有针对性的治理方案做参考,以期达到最优的治理效果。     

Merging genomes with geochemistry in hydrothermal ecosystems

Thermophilic microbial inhabitants of active seafloor and continental hot springs populate the deepest branches of the universal phylogenetic tree, making hydrothermal ecosystems the most ancient continuously inhabited ecosystems on Earth. Geochemical consequences of hot water-rock interactions render these environments habitable and supply a diverse array of energy sources. Clues to the strategies for how life thrives in these dynamic ecosystems are beginning to be elucidated through a confluence of biogeochemistry, microbiology, ecology, molecular biology, and genomics. These efforts have the potential to reveal how ecosystems originate, the extent of the subsurface biosphere, and the driving forces of evolution.     

土壤微塑料污染及生态效应研究进展

微塑料作为一种新型环境污染物,对土壤生态系统构成严重威胁。当前对微塑料的研究多集中于水域生态系统,而对土壤生态系统的影响研究较少。本文综述了土壤微塑料的分类及来源,分离、检测方法及存在问题,总结了土壤微塑料的污染和微塑料对污染物的吸附效应及机理,分析了其对土壤动物、微生物生态及碳、氮等物质循环的影响,最后针对微塑料的生态效应提出展望,为今后土壤微塑料的研究提供了新的思路。     

南京地区斑点叉尾鮰养殖池塘水体微生物群落结构研究

微生物群落在水产养殖中起着重要作用,深入了解微生物群落组成及其构建机制对了解池塘生态功能具有重要意义。本研究采用高通量测序技术对南京地区斑点叉尾鮰(Ictalurus punctatus)养殖池塘水体中细菌群落结构特征进行了分析。结果显示,斑点叉尾鮰养殖池塘水体细菌群落结构呈现出明显的季节性变化,整个年度水体细菌群落呈现出连续的演替特征,冬季与春季、夏季与秋季的细菌群落结构较为相似。优势菌群主要为蓝藻门(Cyanobacteria)、放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)。环境因子中,总溶解性悬浮物(TDS)、水温(Temp)、酸碱度(pH)、亚硝酸盐(NO_2~--N)和总有机碳(TOC)与斑点叉尾鮰养殖池塘水体细菌群落结构有显著相关(P0.05),对细菌群落结构的塑造影响也最大(r~20.6)。     

Magnesium isotopic composition of interplanetary dust particles

The magnesium isotopic composition of some extraterrestrial dust particles has been measured. The particles are believed to be samples of interplanetary dust, a significant fraction of which originated from the disaggregation of comets and may contain preserved isotopic anomalies. Improvements in mass spectrometric and sample preparation techniques have made it possible to measure the magnesium isotopic composition of the dust particles, which are typically 10 micrometers in size and contain on the order of 10(-10) gram of magnesium. Of the 13 samples analyzed, nine have the terrestrial magnesium isotopic composition within 2 parts per thousand, and one shows isotopic mass fractionation of 1.1 percent per mass unit. A subset of the particles, described as chondritic aggregates, are very close to normal isotopic composition, but their normalized isotopic ratios appear to show nonlinear effects of 3 to 4 parts per thousand, which is near the present limit of detection for samples of this size. The isotopic composition of calcium was also determined in one particle and found to be normal within 2 percent. It is clear that the isotopic composition of interplanetary dust particles can be determined with good precision. Collection of dust particles during the earth's passage through a comet tail or an intense meteor stream may permit laboratory analysis of material from a known comet.