This work was funded by Genome BC, Genome Canada, and Coastal Genomics. The authors thank Kirby Cronin and Michael Chan for their help in sample collection and processing. We also would like to acknowledge Thea Van Rossum and Dr. Fiona Brinkman for bioinformatics assistance.

1.水收集和过滤<ol><li>收集来自各部位（ 图1）的淡水样品。通过一系列的过滤器通过样品：1微米的过滤器，0.2微米的过滤器，和30 kDa的截止切向流过滤器，以系统地分开真核生物，细菌和病毒大小的颗粒，分别。 注意：只有在纯化和回收在0.2微米的过滤器（自由生活的细菌）的材料的分析在本报告中进行了说明，但类似的方法可用于从过滤器回收的其它颗粒。 </li></ol> 2.细菌浓度，DNA提取和纯化<ol><li>除去从水过滤系统（示意图， 图2）的0.2微米的膜过滤器（多个）。折叠为0.2μm盘式过滤器在一半并将其放入50ml管与打开的一面朝上。加入5 ml的1×磷酸缓冲液（PBS）及0.01％吐温，pH 7.4中进管。如果一个以上的过滤器的过程中使用的采用每一个过滤器的不同管中。商店管（多个）带过滤器在4℃下直到处理。否则，继续执行步骤2.2。 </li><li>删除50毫升管，用无菌镊子0.2微米的滤膜过滤。在一个培养皿的地方过滤器（多个）（离开PBS缓冲液在管中）。 <ol><li>用无菌镊子和无菌剪刀，剪去滤波器成小条带（1毫升×1厘米）。通过浸泡在70％的异丙醇，用DNA表面去污剂擦拭和与第一类型不同的样品之间的超纯水漂洗消毒镊子和剪刀。 </li></ol></li><li>放置切成条状的过滤器放回同样的50毫升管。加入10 mL的1×PBS和0.01％吐温，pH 7.4中的过滤器，使总共15 ml缓冲液中的50ml管中有。 </li><li>添加6洁净钨珠（直径3）每次50毫升管，覆盖管封口膜和涡大力为20分钟（使用50ml试管涡适配器）。如果MULTIPLE过滤器从一个样品，转移和池中的所有匀浆处理成清洁的50ml管中。离心管在3300 XG为15分钟，在4℃。 </li><li>悬浮颗粒和等份的细菌细胞（〜1ml等份）插入1.7毫升离心管。需要注意的是将有每个样品5微量离心管中。 </li><li>降速的离心管以10,000rpm离心10分钟，并移除大部分上清液降到〜200微升标记。 </li><li>存储所述样品在-80℃下，或进行通过使用市售的DNA分离试剂盒按照制造商的说明提取细菌的DNA。在细菌的DNA提取使用PBS或水作为阴性提取控制和E.大肠杆菌作为阳性对照提取。 </li><li>因为从多个管的DNA被提取，汇集平行子等份从同一样品放入1个2毫升管。然后通过使用包括0.1的溶液进行O / N沉淀体积的3M乙酸钠，2体积的100％乙醇和5微升5微克/微升的线性丙烯酰胺。搅拌均匀，将标本在-80℃。 </li><li>以最大速度离心（17000×g离心）处理30分钟，在4℃。用1ml冰冷的70％乙醇，空气干燥在生物安全柜中于不超过5分钟，重悬DNA沉淀在34微升10毫摩尔Tris-CL，pH值8.5洗沉淀。 注：线性丙烯酰胺有利于O / N沉淀后可视化DNA沉淀。 </li><li>确定使用高灵敏度荧光核酸定量测定和一个微量分光光度计，分别按照制造商的说明（见表材料）的DNA的数量和质量。 注意：如果多个样品制备的时候，可以用于定量双链DNA和板为基础的荧光计/分光光度计的超灵敏荧光核酸测定法来代替。 </li></ol> 3. DNA库准备<ol><li&gt;正常化的基因组DNA的细菌从水样提取到0.2纳克/微升〜浓度。 </li><li>细菌DNA的使用转座子为基础的方法（tagmentation）酶促片段1纳克。添加适配器和索引序列到片段化DNA按照制造商的说明进行操作。受试者tagmented样品的PCR 12个循环，在制造商的说明，在该点的测序索引被并入表示。 </li></ol> 4.自动凝胶尺寸选择<ol><li>跳过在制造商的说明书中所述的标准PCR后清理步骤（见表材料）。大小选择PCR后的样品直接用自动基于凝胶的大小选择平台。 <ol><li>加入3.5微升加样缓冲液到每个样品。 </li><li>根据制造商的协议中，加载样品到电泳工作站，指定的500-800碱基对的大小选择目标，在一个300μl的提取液离子量，使用的是预铸1.5％琼脂糖盒。 </li><li>集中的原始输出材料（300微升）下降到通过乙醇沉淀25微升。 注：另外，用电泳工作站自动浓度的样品通过过滤板和真空歧管更大的数字。 <ol><li>沉淀用0.1倍体积的3M乙酸钠，2体积的100％乙醇和5微升5微克/微升的线性丙烯酰胺的原料的洗脱体积。拌匀，放置样品在-80°CO / N。离心样品在17000×g离心30分钟。 </li><li>丢弃上清液，然后继续用1ml冰冷的70％乙醇洗涤DNA沉淀。 </li><li>离心样品再次在17000×g离心30分钟，弃去上清液，空气干燥，最后重悬DNA沉淀在25微升10毫摩尔Tris-CL，pH值8.5。 </li></ol></li></ol></li><li> （可选）使用1微升的DNA库的大小与自动化凝胶大小选择平台选择做一个五倍稀释使用的Tris-EDTA缓冲溶液，pH为8.0。分析使用基于芯片的毛细管电泳仪，根据生产商的说明来分析双链DNA质量库。 </li></ol> 5.图书馆规范化和测序<ol><li>进行到正常化使用如制造商的指导制备描述库正常化珠粒（包含转座子为基础的文库制备试剂盒）的样品。 <ol><li>可替代地，使用高灵敏度荧光核酸定量测定，接着汇集于等摩尔比，以达到为2nM的终双链DNA浓度测量双链DNA文库。继续以变性，用10微升汇集库和10μl的0.2N的氢氧化钠库，孵育5分钟，在室温。用稀释杂交缓冲液（包含转座子为基础制备试剂盒），以1毫升的最终体积的下午11时05分和浓度变性库。 </li></ol></li><li>加载样品在下一代测序平台S按以下所述制造商的标准测序方案。 </li></ol>

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贾里德R.斯洛博丹·马太J.内斯比特均持有沿海基因组学，是一家私人拥有的不列颠哥伦比亚省公司提供游侠科技股。

适配器二聚体和小尺寸插入优先被测序在现有平台的集群的存在代表了可用率和利用不足的设备的能力15的下降。使用珠击方法结合座子为基础的方法来制备文库可以导致更多的DNA剪切相比萃取4,5的其他方法。然而，提取和文库制备的所有方法可能引入偏倚测序的分布读取8,16。使用自动核酸提取平台，结合一个连接基法的实验观察，似乎没有去除过量的从鸟枪文库适配器?...

Metagenomics involves the sequencing of all the genetic material in a sample to characterize the microbial communities present. It is a complex and expensive process which involves the conversion of extracted nucleic acids into DNA libraries followed by next-generation sequencing. High quality libraries are essential for maximal data output and accurate metagenomics analysis. Environmental samples, such as water samples, often pose significant challenges to generating high quality libraries, due to low amounts of DNA that may also be degraded1-3 and the presence of inhibitors of PCR4-6. 
High quality libraries ideally consist of longer segments of DNA within a narrow range of lengths. In order to maximize the amount of useful data generated per sequencing run, the length of the DNA in the library should be at least as long as the maximum read length of the sequencing method being used. When using a sequencing-by-synthesis technology such as the Illumina MiSeq, the size of the DNA fragments affects the efficiency at which clusters are generated on the flow cell. For instance, when a library contains both shorter and longer DNA fragments, the shorter ones will be over-represented in the sequencing data7,8. In contrast, a library with similarly sized DNA fragments will be proportionally represented in the sequencing data. Many library preparation kits use ligation-based methods to add adapters to the DNA fragments and size selection is necessary to remove adapter dimers that do not contain an insert9,10. There are numerous methods11,12 to achieve this but the one technique that gives the most consistent results is the electrophoretic separation of DNA followed by the recovery of the desired lengths of DNA13,14. This process can be performed manually for a small number of samples, but when faced with processing hundreds of samples, automated solutions are required. The currently available platforms for automated gel size selection are low throughput and new platforms are needed to process large numbers of samples for sequencing. The Ranger Technology can be integrated with existing liquid handling workstations to enable the use of agarose gel electrophoresis for size selection and analytical purposes on a scale that satisfies today&#8217;s high throughput environment.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Peristaltic pump Masterflex P/S 1400 Series</td>
			<td>Thermo Scientific&#160;</td>
			<td>1400-1620</td>
			<td></td>
		</tr>
		<tr>
			<td>0.2 &#181;m Supor Membrane</td>
			<td>VWR</td>
			<td>CA28143-969</td>
			<td>Pall Corporation, Ann Harbor, MI</td>
		</tr>
		<tr>
			<td>Tungsten carbide beads 3 mm (200)</td>
			<td>Qiagen</td>
			<td>69997</td>
			<td></td>
		</tr>
		<tr>
			<td>Isopropyl alcohol 70%</td>
			<td>Jedmon Products</td>
			<td>825751</td>
			<td>Healthcare Plus</td>
		</tr>
		<tr>
			<td>DNA away</td>
			<td>VWR</td>
			<td>7010</td>
			<td>Molecular BioProducts, Inc. San Diego, CA</td>
		</tr>
		<tr>
			<td>Milli-Q water purification system</td>
			<td>Fisher Scientific</td>
			<td>ZMQS6VF0Y</td>
			<td>Merck Millipore. This system has been discontinued.</td>
		</tr>
		<tr>
			<td>20 X PBS pH 7.5</td>
			<td>VWR</td>
			<td>E703-1L</td>
			<td>Amresco, Inc., Solon, OH</td>
		</tr>
		<tr>
			<td>Tween 20</td>
			<td>Fisher Scientific</td>
			<td>BP337-100</td>
			<td>Fisher chemicals</td>
		</tr>
		<tr>
			<td>Vortex adapter for 2 (50 ml) tubes</td>
			<td>VWR</td>
			<td>13000-V1-50</td>
			<td>MoBio, Carlsbad, CA</td>
		</tr>
		<tr>
			<td>Vortex-Genie 2, 120V (Model G560)</td>
			<td>VWR</td>
			<td>SI-0236</td>
			<td>Scientific Industries, Inc.</td>
		</tr>
		<tr>
			<td>Beckman Centrifuge</td>
			<td>Raeyco Lab Equipment Systems Management Ltd</td>
			<td>Model J-6B</td>
			<td></td>
		</tr>
		<tr>
			<td>PowerLyzer Powersoil DNA isolation kit</td>
			<td>VWR</td>
			<td>12855-100</td>
			<td>MoBio, Carlsbad, CA</td>
		</tr>
		<tr>
			<td>Vortex adapter for 24 (1.5-2 ml) tubes</td>
			<td>VWR</td>
			<td>13000-V1-24</td>
			<td>MoBio, Carlsbad, CA</td>
		</tr>
		<tr>
			<td>Microfuge 18 centrifuge</td>
			<td>Beckman Coulter</td>
			<td>367160</td>
			<td></td>
		</tr>
		<tr>
			<td>Nimbus Select workstation with Ranger Technology</td>
			<td>Hamilton Robotics</td>
			<td>92720-01</td>
			<td>Includes the liquid handling workstation and integrated Ranger Tech (electrophoresis hardware)</td>
		</tr>
		<tr>
			<td>Ranger reagent kit</td>
			<td>Coastal Genomics</td>
			<td>CG-10600-150-12-21</td>
			<td>Includes loading buffer and cassettes</td>
		</tr>
		<tr>
			<td>Ethyl alcohol (anhydrous)</td>
			<td>Commercial Alcohols</td>
			<td>P016EAAN</td>
			<td>Greenfield Ethanol</td>
		</tr>
		<tr>
			<td>Sodium acetate</td>
			<td>Sigma-Aldrich</td>
			<td>S2889-250G</td>
			<td></td>
		</tr>
		<tr>
			<td>Linear acrylamide (5 mg/ml)</td>
			<td>Life Technologies</td>
			<td>AM9520</td>
			<td>Ambion</td>
		</tr>
		<tr>
			<td>Eppendorf refrigerated centrifuge</td>
			<td>Raeyco Lab Equipment Systems Management Ltd.</td>
			<td>5417R</td>
			<td></td>
		</tr>
		<tr>
			<td>Buffer EB (250 ml)</td>
			<td>Qiagen</td>
			<td>19086</td>
			<td></td>
		</tr>
		<tr>
			<td>NanoDrop 1000 Spectrophotometer</td>
			<td>Thermo Scientific</td>
			<td>ND-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit fluorometer</td>
			<td>Life Technologies</td>
			<td>Q32857</td>
			<td>Invitrogen. This product has been discontinued.</td>
		</tr>
		<tr>
			<td>Qubit dsDNA HS assay kit</td>
			<td>Life Technologies</td>
			<td>Q32854</td>
			<td>Invitrogen</td>
		</tr>
		<tr>
			<td>High sensitivity DNA reagent</td>
			<td>Agilent Technologies</td>
			<td>5067-4626</td>
			<td></td>
		</tr>
		<tr>
			<td>High sensitivity DNA chips</td>
			<td>Agilent Technologies</td>
			<td>5067-4626</td>
			<td></td>
		</tr>
		<tr>
			<td>Agilent 2011 Bioanalyzer</td>
			<td>Agilent Technologies</td>
			<td>G2938B</td>
			<td></td>
		</tr>
		<tr>
			<td>Nextera XT DNA sample preparation kit</td>
			<td>Illumina</td>
			<td>FC-131-1024</td>
			<td></td>
		</tr>
		<tr>
			<td>Nextera XT index kit</td>
			<td>Illumina</td>
			<td>FC-131-1001</td>
			<td></td>
		</tr>
		<tr>
			<td>MiSeq reagent kit v2 (500-cycles)</td>
			<td>Illumina</td>
			<td>MS-102-2003</td>
			<td></td>
		</tr>
		<tr>
			<td>Miseq system</td>
			<td>Illumina</td>
			<td>SY-410-1003</td>
			<td></td>
		</tr>
	</tbody>
</table>

automated gel size selection to improve the quality of next-generation sequencing libraries prepared from environmental water samples

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA libraries are needed for optimal results from next-generation sequencing. Environmental samples such as water may have low quality and quantities of DNA as well as contaminants that co-precipitate with DNA. The mechanical and enzymatic processes involved in extraction and library preparation may further damage the DNA. Gel size selection enables purification and recovery of DNA fragments of a defined size for sequencing applications. Nevertheless, this task is one of the most time-consuming steps in the DNA library preparation workflow. The protocol described here enables complete automation of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments. 
In this study, we describe a high-throughput approach to prepare high quality DNA libraries from freshwater samples that can be applied also to other environmental samples. We used an indirect approach to concentrate bacterial cells from environmental freshwater samples; DNA was extracted using a commercially available DNA extraction kit, and DNA libraries were prepared using a commercial transposon-based protocol. DNA fragments of 500 to 800 bp were gel size selected using Ranger Technology, an automated electrophoresis workstation. Sequencing of the size-selected DNA libraries demonstrated significant improvements to read length and quality of the sequencing reads.

DNA浓度和质量评估 细菌的DNA浓度范围为0.01至0.11纳克/毫升％的不同流域部位的水样品（ 见表1）。 DNA细菌部分分离了一个260/280和A 260/230比例为1.4〜1.8和0.3〜1.6，分别为。虽然一些甲二百三十〇分之二百六十比率相对较低，没有明显的抑制作用，观察在制备的文库和其它下游应用。这些应用包括PCR和qPCR测试靶向16S rRNA和CPN<...

Watch this Scientific Journal Video about Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples at JoVE.com

Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples

This manuscript describes an automated gel size selection approach for purifying DNA fragments for next-generation sequencing. The Ranger Technology provides complete automation of the entire process of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments allowing for high-throughput and high quality next-generation sequencing libraries.

自动凝胶尺寸选择，以提高下一代测序文库的质量，从环境水样准备

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA ...

automated-gel-size-selection-to-improve-quality-next-generation

Research

JoVE Journal

Environment

10.4K 次观看.  The University of British Columbia. This manuscript describes an automated gel size selection approach for purifying DNA fragments for next-generation sequencing. The Ranger Technology provides complete automation of the entire process of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments allowing for high-throughput and high quality next-generation sequencing libraries. 

视频: Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. The standardized sampling component of the method concentrates viruses that may be present in water by passage of a minimum specified volume of water through an electropositive cartridge filter. The minimum specified volumes for surface and finished/ground water are 300 L and 1,500 L, respectively. A major method limitation is the tendency for the filters to clog before meeting the sample volume requirement. Studies using two different, but equivalent, cartridge filter options showed that filter clogging was a problem with 10% of the samples with one of the filter types compared to 6% with the other filter type. Clogging tends to increase with turbidity, but cannot be predicted based on turbidity measurements only. From a cost standpoint one of the filter options is preferable over the other, but the water quality and experience with the water system to be sampled should be taken into consideration in making filter selections.

EPA Method 1615 uses an electropositive filter to concentrate enteroviruses and noroviruses in environmental and drinking waters. This manuscript describes the procedure for collecting samples for Method 1615 analyses.

EPA方法1615测量肠道病毒和诺瓦克病毒发生水由文化和RT-qPCR的了。病毒样本的收集I.

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. ...

科研

环境科学

Physical Isolation of Endospores from Environmental Samples by Targeted Lysis of Vegetative Cells

Endospore formation is a survival strategy found among some bacteria from the phylum Firmicutes. During endospore formation, these bacteria enter a morpho-physiological resting state that enhances survival under adverse environmental conditions. Even though endospore-forming Firmicutes are one of the most frequently enriched and isolated bacterial groups in culturing studies, they are often absent from diversity studies based on molecular methods. The resistance of the spore core is considered one of the factors limiting the recovery of DNA from endospores. We developed a method that takes advantage of the higher resistance of endospores to separate them from other cells in a complex microbial community using physical, enzymatic and chemical lysis methods. The endospore-only preparation thus obtained can be used for re-culturing or to perform downstream analysis such as tailored DNA extraction optimized for endospores and subsequent DNA sequencing. This method, applied to sediment samples, has allowed the enrichment of endospores and after sequencing, has revealed a large diversity of endospore-formers in freshwater lake sediments. We expect that the application of this method to other samples will yield a similar outcome.

A method to single out bacterial endospores from complex microbial communities was developed to perform tailored culture or molecular studies of this group of bacteria.

从环境样品中的内生孢子通过无性细胞定向裂解物理隔离

Endospore formation is a survival strategy found among some bacteria from the phylum Firmicutes. During endospore formation, these bacteria enter a ...

A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and enables to perform rapid, automated and simple SPE. The pre-concentrated solution is compatible with analysis by immunoassay, with a low organic solvent content. A method is described for the extraction and pre-concentration of natural hormone 17&#946;-estradiol in 100 ml water samples. Reverse phase SPE is performed with octadecyl-silica sorbent and elution is done with 200 &#181;l of methanol 50% v/v. Eluent is diluted by adding di-water to lower the amount of methanol. After preparing manually the SPE column, the overall procedure is performed automatically within 1 hr. At the end of the process, estradiol concentration is measured by using a commercial enzyme-linked immune-sorbent assay (ELISA). 100-fold pre-concentration is achieved and the methanol content in only 10% v/v. Full recoveries of the molecule are achieved with 1 ng/L spiked de-ionized and synthetic sea water samples.

A protocol for the extraction and pre-concentration of estradiol from water samples by using an automated and miniaturized system is presented.

对水样的自动固相萃取小污染物的免疫学分析的简单方法

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and ...

Use of a Filter Cartridge for Filtration of Water Samples and Extraction of Environmental DNA

Recent studies demonstrated the use of environmental DNA (eDNA) from fishes to be appropriate as a non-invasive monitoring tool. Most of these studies employed disk fiber filters to collect eDNA from water samples, although a number of microbial studies in aquatic environments have employed filter cartridges, because the cartridge has the advantage of accommodating large water volumes and of overall ease of use. Here we provide a protocol for filtration of water samples using the filter cartridge and extraction of eDNA from the filter without having to cut open the housing. The main portions of this protocol consists of 1) filtration of water samples (water volumes &#8804;4 L or &gt;4 L); (2) extraction of DNA on the filter using a roller shaker placed in a preheated incubator; and (3) purification of DNA using a commercial kit. With the use of this and previously-used protocols, we perform metabarcoding analysis of eDNA taken from a huge aquarium tank (7,500 m3) with known species composition, and show the number of detected species per library from the two protocols as the representative results. This protocol has been developed for metabarcoding eDNA from fishes, but is also applicable to eDNA from other organisms.

We describe a protocol for filtration of water samples with a filter cartridge and extraction of environmental DNA (eDNA) without having to cut open the housing to remove the filter. This protocol is developed for metabarcoding eDNA from fishes, but is also applicable to eDNA from other organisms.

滤芯水过滤样品和环境DNA的提取使用

Recent studies demonstrated the use of environmental DNA (eDNA) from fishes to be appropriate as a non-invasive monitoring tool. Most of these studies ...

Controlled-release of Chlorine Dioxide in a Perforated Packaging System to Extend the Storage Life and Improve the Safety of Grape Tomatoes

A controlled-release chlorine dioxide (ClO2) pouch was developed by sealing a slurry form of ClO2 into semipermeable polymer film; the release properties of the pouch were monitored in containers with or without fruit. The pouch was affixed to the inside of a perforated clamshell containing grape tomatoes, and the effect on microbial population, firmness, and weight loss was evaluated during a 14 day storage period at 20 &#176;C. Within 3 days, the ClO2 concentration in the clamshells reached 3.5 ppm and remained constant until day 10. Thereafter, it decreased to 2 ppm by day 14. The ClO2 pouch exhibited strong antimicrobial activity, reducing Escherichia coli populations by 3.08 log CFU/g and Alternaria alternata populations by 2.85 log CFU/g after 14 days of storage. The ClO2 treatment also reduced softening and weight loss and extended the overall shelf life of the tomatoes. Our results suggest that ClO2 treatment is useful for extending the shelf life and improving the microbial safety of tomatoes during storage without impairing their quality.

Here, we describe a protocol for the application of a novel, slow-release ClO2 product that reduces spoilage and extends the shelf life of fresh fruit. The slow-release ClO2 product was added to standard commercial grape tomato packaging and tested against Escherichia coli and Alternaria alternata.

在穿孔的包装系统二氧化氯的控释，延长贮藏寿命，提高葡萄番茄的安全

A controlled-release chlorine dioxide (ClO2) pouch was developed by sealing a slurry form of ClO2 into semipermeable polymer film; the release properties ...

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

Microplastics act as vector of potentially toxic organic contaminants with unpredictable effects. This protocol describes an alternative methodology for assessing the levels of organochlorine pesticides adsorbed on plastic pellets and identifying the polymer chemical structure. The focus is on pressurized fluid extraction and attenuated total reflectance Fourier transform infrared spectroscopy.

从塑料颗粒中提取有机氯农药和塑料类型分析

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment ...

Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron (Oxy)Hydroxides, Trace Elements, and Bacteria

Fate and speciation of trace elements (TEs), such as arsenic (As) and mercury (Hg), in aquifers are closely related to physio-chemical conditions, such as redox potential (Eh) and pH, but also to microbial activities that can play a direct or indirect role on speciation and/or mobility. Indeed, some bacteria can directly oxidize As(III) to As(V) or reduce As(V) to As(III). Likewise, bacteria are strongly involved in Hg cycling, either through its methylation, forming the neurotoxin monomethyl mercury, or through its reduction to elemental Hg&#176;. The fates of both As and Hg are also strongly linked to soil or aquifer composition; indeed, As and Hg can bind to organic compounds or (oxy)hydroxides, which will influence their mobility. In turn, bacterial activities such as iron (oxy)hydroxide reduction or organic matter mineralization can indirectly influence As and Hg sequestration. The presence of sulfate/sulfide can also strongly impact these particular elements through the formation of complexes such as thio-arsenates with As or metacinnabar with Hg.
Consequently, many important questions have been raised on the fate and speciation of As and Hg in the environment and how to limit their toxicity. However, due to their reactivity towards aquifer components, it is difficult to clearly dissociate the biogeochemical processes that occur and their different impacts on the fate of these TE.
To do so, we developed an original, experimental, column setup that mimics an aquifer with As- or Hg-iron-oxide rich areas versus iron depleted areas, enabling a better understanding of TE biogeochemistry in anoxic conditions. The following protocol gives step by step instructions for the column set-up either for As or Hg, as well as an example with As under iron and sulfate reducing conditions.

Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron OxyHydroxides, Trace Elements, and Bacteria

Fate and speciation of arsenic and mercury in aquifers are closely related to physio-chemical conditions and microbial activity. Here, we present an original experimental column setup that mimics an aquifer and enables a better understanding of trace element biogeochemistry in anoxic conditions. Two examples are presented, combining geochemical and microbiological approaches.

用于研究铁 (氧) 氢氧化物、微量元素和细菌之间厌氧生物地球化学相互作用的实验柱装置

Fate and speciation of trace elements (TEs), such as arsenic (As) and mercury (Hg), in aquifers are closely related to physio-chemical conditions, such as ...

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds

Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. However, they are vulnerable parts of the landscapes that are often poorly understood and understudied. Land use and management practices, as well as climate change are thought to be a contribution to the global amphibian decline. However, more research is needed to understand the extent of these impacts. Here, we present methodology for characterizing a vernal pond's morphology and detail a monitoring station that can be used to collect water quantity and quality data over the duration of a vernal pond's hydroperiod. We provide methodology for how to conduct field surveys to characterize the morphology and develop stage-storage curves for a vernal pond. Additionally, we provide methodology for monitoring the water level, temperature, pH, oxidation-reduction potential, dissolved oxygen, and electrical conductivity of water in a vernal pond, as well as monitoring rainfall data. This information can be used to better quantify the ecosystem services that vernal ponds provide and the impacts of anthropogenic activities on their ability to provide these services.

Understanding the ecosystem services and processes provided by vernal ponds and the impacts of anthropogenic activities on their ability to provide these services requires intensive hydrologic monitoring. This sampling protocol using in-situ monitoring equipment was developed to understand the impact of anthropogenic activities on water levels and quality.

春季池塘连续水文水质监测

Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. ...

Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric hydroxide (GFH), with little effort and high reliability. The phosphonate, e.g., nitrilotrimethylphosphonic acid (NTMP), is brought into contact with the GFH in a rotator in a solution buffered by an organic acid (e.g., acetic acid) or Good buffer (e.g., 2-(N-morpholino)ethanesulfonic acid) [MES] and N-cyclohexyl-2-hydroxyl-3-aminopropanesulfonic acid [CAPSO]) in a concentration of 10 mM for a specific time in 50 mL centrifuge tubes. Subsequently, after membrane filtration (0.45 &#181;m pore size), the total phosphorus (total P) concentration is measured using a specifically developed determination method (ISOmini). This method is a modification and simplification of the ISO 6878 method: a 4 mL sample is mixed with H2SO4 and K2S2O8 in a screw cap vial, heated to 148-150 &#176;C for 1 h and then mixed with NaOH, ascorbic acid and acidified molybdate with antimony(III) (final volume of 10 mL) to produce a blue complex. The color intensity, which is linearly proportional to the phosphorus concentration, is measured spectrophotometrically (880 nm). It is demonstrated that the buffer concentration used has no significant effect on the adsorption of phosphonate between pH 4 and 12. The buffers, therefore, do not compete with the phosphonate for adsorption sites. Furthermore, the relatively high concentration of the buffer requires a higher dosage concentration of oxidizing agent (K2S2O8) for digestion than that specified in ISO 6878, which, together with the NaOH dosage, is matched to each buffer. Despite the simplification, the ISOmini method does not lose any of its accuracy compared to the standardized method.

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric hydroxide, with little effort and high reliability. In a buffered solution, the phosphonate is brought into contact with the adsorbent using a rotator and then analyzed via a miniaturized phosphorus determination method.

用小型化磷测定法测定膦酸在粒状氢氧化铁上吸附的优化方法

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric ...

Composition and Distribution Analysis of Bioaerosols Under Different Environmental Conditions

Variable microorganisms in particulate matter (PM) under different environmental conditions may have significant impacts on human health. In this study, we described a protocol for multiple analyses of the biological compositions in environmental PM. Five experiments are presented: (1) PM number monitoring by using a laser particle counter; (2) PM collection by using a cyclonic aerosol sampler; (3) PM collection by using a high-volume air sampler with filters; (4) culturable microbes collection by the Andersen six-stage sampler; and (5) detection of biological composition of environmental PM by bacterial 16SrDNA and fungal ITS region sequencing. We selected hazy days and a livestock farm as two typical examples of the application in this protocol. In this study, these two sampling methods, cyclonic aerosol sampler and filter sampler, showed different sampling efficiency. The cyclonic aerosol sampler performed much better in terms of collecting bacteria, while these two methods showed the same efficiency in collecting fungi. Filter samplers can work under low temperature conditions while cyclonic aerosol samplers have a sampling limitation for temperature. A solid impacting sampler, such as an Andersen six-stage sampler, can be used to sample bioaerosols directly into the culture medium, which increases the survival rate of culturable microorganisms. However, this method mainly relies on culture while more than 99% of microbes cannot be cultured. DNA extracted from the culturable bacteria collected by the Andersen six-stage sampler and samples collected by cyclonic aerosol sampler and filter sampler were detected by bacterial 16S rDNA and fungal ITS region sequencing.All the methods above may have wide application in many fields of study, such as environmental monitoring and airborne pathogen detection. From these results, we can conclude that these methods can be used under different conditions and may help other researchers further explore the health impacts of environmental bioaerosols.

Understanding the biological composition of environmental particulate matter is important for the study of its significant impacts on human health and disease spread. Here, we used three types of bioaerosol sampling methods and a biological analysis of airborne microbes to better explore airborne microbial communities under different environmental conditions.

不同环境条件下生物气溶胶的组成及分布分析

Variable microorganisms in particulate matter (PM) under different environmental conditions may have significant impacts on human health. In this study, ...