This work was funded, in part, by the Great Lakes Fishery Commission and the Annis Water Resources Institute. Use of trade, product, or firm names does not imply endorsement by the U. S. Government. This article is Contribution 1867 of the U. S. Geological Survey Great Lakes Science Center.

1室内実験<ol><li>実験中に捕食魚に供給される獲物の魚を入手します。好ましくは、これらの獲物の魚は、フィールドに入力されてい凍結し、約-30°Cで保存してください。獲物の魚のための潜在的な供給源としての商業漁業を考えてみましょう。 </li><li>実験室タンクに捕食魚を導入する実験に使用する。 15捕食魚まで870リットルのタンクのそれぞれに導入し、最大30捕食魚されてきたこれまでの研究16,18で2380リットルのタンクのそれぞれに導入されている。 </li><li>選択した獲物の魚の食事に捕食魚を順応。順化後、捕食魚は、実験を開始する前に、1〜3ヶ月間、このダイエットを維持する必要があります。 </li><li>ランダムに獲物の魚のバッチから10〜20の複合サンプルを選択することで、獲物の魚のサンプルを置いておきます。複合サンプル中の捕食魚の数は、獲物のサイズに応じて、3〜100の範囲であり得る魚。各複合試料は凍結し、袋詰めし、約-30℃で保存し、二重にする必要があります。 </li><li>各タンクに魚を30〜50％の犠牲にして実験を開始する。 <ol><li> 、魚を安楽死させる大規模なプラスチック容器に水45リットルでFinquelの8グラムを混合し、次いでFinquel液の入った容器に魚を置きます。 </li><li>いったん安楽死させ、処理時まで約-30°Cで二重包装した後、袋に1タンクから犠牲に魚のすべてを置き、店。 </li><li>各タンクに残っている魚をそれぞれ秤量し、重さを記録。麻酔薬は、おそらく計量を行うために必要とされるであろう。 </li><li> 、魚を麻酔大型プラスチック容器内の水の45リットルでFinquelの4.6グラムを混ぜ、その後、Finquel液の入った容器に魚を置きます。 </li><li>魚を計量する前に有効にするには、麻酔薬のための数分待ちます。 </li></ol></li><li>実験のそれぞれの日には、解凍適切な獲物の魚の量、およびおよそ1〜5グラムの重さの断片に獲物の魚を切った。各タンクに捕食魚のピースをドロップし、各タンクに配置される獲物の魚の量を計量し、捕食者の魚を養うために約1時間を可能にします。そして、全ての食べ残しを取り除く約20分間空気乾燥さ食べ物を許可してから、タンクのそれぞれについて、食べ残しの重量を量る。タンク内に配置された食物の量と、毎日のタンクのそれぞれについて、食べ残しの量を記録します。 注：代表的な実験のために、レイクトラウトは、それらがそれぞれ18日目1給餌期間中に消費するように多くの食べ物として供給した。しかし、捕食者の魚も固定配給16,19上に配置することができた。 </li><li>各タンクに残っている捕食魚のすべてを犠牲にして実験を終了します。 、魚を安楽死させる大規模なプラスチック容器に水45リットルでFinquelの8グラムを混合し、次いでFinquel液の入った容器に魚を置きます。録音トン犠牲に魚のそれぞれの彼は体重。信頼性の高い結果を得るためには、実験は、好ましくは少なくとも130日間、少なくとも100日間、実行する必要があります。 1袋にタンクから魚のすべてを置き、その後二重袋、処理時まで約-30℃で保存してください。 </li></ol> 2魚の均質化<ol><li>捕食者の魚、および/または解凍するための獲物の魚の複合材料のセットを選択します。複合材料は、部分的に解凍することができます。各複合材料は、均質化する0.5〜1時間が必要な場合があります。 </li><li>適切なサイズのブレンダーを使用して、複合体のそれぞれを均質化する。各複合のために、洗浄アセトンすすぎ、ラベル瓶にホモジネート（50〜100グラム）のサンプルを配置します。その後、瓶キャップや処理の時まで約-30℃で瓶を保管。 </li><li>魚を均質化するために使用されるすべての機器を洗浄した後、適切にサンプルの間、蒸留水、メタノールですすいでください。 </li></ol> 3。抽出<ol><li> 20.0グラムを量りの200mlのビーカーに均質化された魚の組織を解凍した。 </li><li>硫酸ナトリウムの約40グラムを加え、へらでよく混ぜる。 </li><li>抽出物中の20 ng / mlでの最終濃度をもたらす濃度でサロゲートスパイク同族体30を含む溶液を、61、161、および166スパイクを追加します。 </li><li> 20分毎に混合しながら、サンプルを室温で乾燥することができます。 </li><li>サンプルは、サンプルが抽出のための準備ができて、その時点で乾燥砂の一貫性に到達することを許可します。 </li><li>テフロン沸騰チップ、ソックスレーおよびコンデンサを含む500mlフラスコでソックスレー抽出装置を設定します。 </li><li>粗フリットディスクボトムや紙シンブルのガラスシンブルに干物混合物を追加します。 </li><li>サンプルに使用ビーカーに、50％ヘキサン及び50％ジクロロメタン150mlを加え、スパチュラでビーカーの壁を掻き取りながら撹拌する。 </li><li>ソックスレー通ってサイクルに装着フラスコによるソックスレーのトップに溶剤を移し、それを許可フラスコへ。 </li><li>再び150ミリリットルで2回繰り返します。 </li><li>発熱体に付着したフラスコをソックスレーを配置し、コンデンサーを接続します。 </li><li>発熱体をオンにして、穏やかな沸騰に溶剤を持参し、冷たい水が凝縮器に供給されていることを確認しながら16時間、最低取り出す。 </li><li>溶剤を冷却させた後、試料フラスコのいずれかが水を含んでいないか確認してください。水を硫酸ナトリウムにより吸収されるまで水を含有するものフラスコために、硫酸ナトリウムやスワールを追加する。 </li><li>窒素サンプルコンセントレータまたは温水浴でKadernaデンマーク（KD）ガラス製品のセットアップを使用してサンプルを濃縮する。 </li><li>試料は2ml未満の体積まで蒸発し、次いで5mlのメスフラスコに用いられるガラス製品からサンプルを転送するためにヘキサンの小さい洗浄液を用いて、5 mlの最終容積に戻すことができるようにする。 </li><li> 10mlのバイアルに移し、サンプル情報とラベルを付けます。 </li></ol><ol><li>活性シリカゲル100gに濃硫酸44グラムを追加することにより酸性化したシリカゲルを準備します。 </li><li>底部にガラスウールの小さなプラグを含む小さなクロマトグラフィーカラムに酸性化し、10gのシリカゲルを添加する。 </li><li> 10mlのヘキサンでカラムを前洗浄した後、カラムに試料抽出物の1ミリリットルを追加します。 </li><li>ヘキサン20mlでカラムを溶出し、テーパ20mlのガラス管中に収集する。 </li><li>窒素気流下で窒素蒸発器（N-バップ）装置上でガラス管を配置し、熱水に浸漬した。 </li><li> 1ml未満に蒸発させますが乾燥するまではない。 </li><li> N-バップ装置から取り外し、ヘキサンの小さな洗浄液を1ミリリットルのメスフラスコに移す。 </li><li>サンプル情報で標識した1.8ミリリットルオートサンプラーバイアルに移す。 </li><li>バイアルに内部標準4μlのスパイク。サンプルは現在、分析のための準備ができました。 </li></ol> 5。アナル負化学イオン化を用いた質量分析 - ガスクロマトグラフィーによるysis <ol><li>計器を校正する標準規格を使用します。基準がよく分離同族体の基からなる混合物中で利用できます。混合物1-5はほぼArochlors 1016、1221、1232、1242、1248、1254に見られる同族体の全てから成り、1260ミックス1は、マルチレベルキャリブレーションミックスとして使用され、システムの線形性は、少なくとも調製することによって確認される2および100 ng / mlの間の濃度で5較正レベル。ミックス2-5は、各同族のためのシングルポイントキャリブレーションとして使用されている。 </li><li>試薬ガスなどのキャリアガス（1ml /分）及びメタン等の水素と負化学イオン化モードでの質量分析システム - クロマトグラフィーを設定する。 </li><li>分離のための0.25μmの膜厚で、DB-XLBで被覆された溶融シリカキャピラリカラム（内径0.25mm×60メートル）を使用します。 26次いで25℃/分で、60〜212℃のオーブン温度プログラム、1℃/分で0℃、4℃/分、その後280℃で4分間の最終保持時間を有する。インジェクタおよびトランスファーライン温度は280℃に設定してください。スプリットレス注入モードを用いた試料1〜2μLを注入する。 </li><li> 13 C標識デカクロロビフェニルを用いた内部標準法により、すべての標準液およびサンプルを分析する。 </li><li>第2のソース標準とアロクロール1242および1260を実行して、初期校正のチェックを実行してから、このチェック·プロシージャからの観察量のアロクロール同族の予測値を比較します。 </li><li>すべての試料の初期キャリブレーション手順が正常に遂行された後、完全な分析。キャリブレーションが初期較正の較正混合物のいずれかを使用して、すべての10個のサンプルをチェックして実行する。 </li></ol>ネット栄養転送効率の6。計算<ol><li>ネット栄養転送効率を計算し、γ、各組み合わせoを用以下の式を用いてfのタンクとPCB同族。 <img alt="式（1）" fo:content-width="2in" src="/files/ftp_upload/51496/51496eq1.jpg" /> [PCB fは ]実験終了時にタンク内の捕食魚の平均PCB同族体濃度であり、W fは 、実験の終了時にタンク内の捕食魚の平均重量である[PCB i]は私は実験開始時捕食魚の平均重量であり、摂取されたPCBの同族体の量は、重量を指すW実験開始時タンク内の捕食魚の平均のPCB同族体の濃度であり、 PCB同族体は、実験の過程でタンク内の各レイクトラウトにより、平均して、摂取した。 </li><li>タンクDURに捕食魚ごとに食べて獲物の魚の平均量（重量）によって捕食魚の複合材料でのPCB同族体の平均濃度を乗じて上式の分母を計算する実験の全過程をる。 </li></ol>

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G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+half-lives+of+polychlorinated+biphenyl+(PCB)+congeners+in+whole+fish+and+muscle+of+rainbow+trout+(Salmo+gairdneri).">Biological half-lives of polychlorinated biphenyl (PCB) congeners in whole fish and muscle of rainbow trout (Salmo gairdneri).</a> Canadian Journal of Fisheries and Aquatic Sciences. 40 (9), 1388-1394 (1983).</li><li>Gobas, F. A. P. C., Wilcockson, J. B., Russell, R. W., Haffner, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+of+biomagnification+in+fish+under+laboratory+and+field+conditions.">Mechanism of biomagnification in fish under laboratory and field conditions.</a> Environmental Science and Technology. 33 (1), 133-141 (1999).</li><li>Dmitrovic, J., Chan, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+polychlorinated+biphenyl+congeners+in+human+milk+by+gas+chromatography+&#8211;+negative+chemical+ionization+mass+spectrometry+after+sample+clean-up+by+solid-phase+extraction.">Determination of polychlorinated biphenyl congeners in human milk by gas chromatography &#8211; negative chemical ionization mass spectrometry after sample clean-up by solid-phase extraction.</a> Journal of Chromatography B. 778 (1-2), 147-155 (2002).</li><li>Zorn, M. E., Gibbons, R. D., Sonzogni, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Weighted+least-squares+approach+to+calculating+limits+of+detection+and+quantification+by+modeling+variability+as+a+function+of+concentration.">Weighted least-squares approach to calculating limits of detection and quantification by modeling variability as a function of concentration.</a> Analytical Chemistry. 69 (15), 3069-3075 (1997).</li></ol>

γの最も正確な推定値では、実験者は正確に実験中のタンクやタンクのそれぞれに食べ残しの量のそれぞれに配置された食物の量の両方を追跡することができなければならない。これを実現するために、実験者はタンクから食べ残しをすべて削除し、正確に重量を測定することができなければならない。実際に捕食魚に食べられ、食物の正確なトラッキングに加えて、γの正確な推定はまた?...

Of all of the factors affecting the rate at which fish accumulate contaminants, the efficiency with which fish retain contaminants from the food that they eat is one of the most important1-3. Risk assessment models have been developed to predict future risks to both people and wildlife eating contaminated fish under various scenarios of environmental contamination, and the reliability of these predictions critically depends on the accuracy of the estimates of the efficiency at which fish retain contaminants from their food4.
The efficiency with which the contaminant in the food ingested by the predator is transported through the gut wall is known as gross trophic transfer efficiency5. A portion of the quantity of the contaminant transported through the gut wall of the predator may eventually be lost through depuration and/or metabolic transformation. The efficiency with which the contaminant in the food ingested by the predator is retained by the predator, including any losses due to elimination and metabolic transformation, is known as net trophic transfer efficiency6.
Gross trophic transfer efficiency of organic contaminants to fish from their prey appears to vary with the contaminant&#8217;s chemical properties, including lipid affiliation as measured by the octanol-water partition coefficient, Kow3,7. According to an empirical relationship developed by Thomann3, gross trophic transfer efficiency is relatively high when log Kow is equal to a value between 5 and 6. Gross trophic transfer efficiency declines exponentially at a rate of 50% per unit of log Kow as log Kow increases from 6 to 10, according to the Thomann3 relationship.
Nevertheless, the gross and net trophic transfer efficiencies of polychlorinated biphenyl (PCB) congeners to fish from their prey do not appear to follow the Thomann3 relationship in most cases. Although the trophic transfer efficiencies of PCB congeners to lake whitefish (Coregonus clupeaformis) from its food followed the relationship proposed by Thomann8, trophic transfer efficiencies of PCB congeners were either just weakly related or not related at all to log Kow for Atlantic salmon (Salmo salar)9, rainbow trout (Oncorhynchus mykiss)10, coho salmon (Oncorhynchus kisutch)11, and northern pike (Esox lucius)11.
The overall goal of this study was to present a laboratory technique for estimating the net trophic transfer efficiencies of PCB congeners to a piscivorous fish from its prey. Lake trout (Salvelinus namaycush) was chosen as the piscivorous fish for our experiment because lake trout are relatively easy to maintain in laboratory tanks. Bloater (Coregonus hoyi) was selected as the prey fish to be fed to the lake trout because bloater is eaten by lake trout in its natural setting12. In addition, we determined whether the net trophic transfer efficiencies for lake trout estimated from our laboratory experiment followed the Thomann3 relationship. We also determined whether the degree of activity by the lake trout had a significant effect on net trophic transfer efficiency (&#947;) of the PCB congeners. Activity by lake trout in the Laurentian Great Lakes is believed to have recently increased because changes in the food webs have caused lake trout to allocate more energy toward searching for food13. Lake trout were forced to exercise in one set of tanks by subjecting these lake trout to relatively high flow rates, whereas the other lake trout were permitted to remain relatively inactive by subjecting them to relatively low flow rates. Finally, the specific details of our laboratory procedure that need to be carefully followed to ensure the highest degree of accuracy in the &#947; estimates and to make the laboratory results applicable to the field are discussed, as well as future directions for research building on our laboratory technique. Net trophic transfer efficiency can be estimated both in the laboratory and in the field, and advantages and disadvantages are associated with both approaches. Accuracy in the estimate of &#947; depends on the accuracy of the estimate of food consumption. The amount of food eaten by fish in the laboratory can be accurately determined when proper protocols are followed, whereas the amount of food eaten by fish in the field is typically estimated via bioenergetics modeling. Use of bioenergetics modeling to derive the amount of food eaten has the potential to introduce a substantial amount of uncertainty into the estimates of food consumption. Fish bioenergetics models have been shown to estimate food consumption with no detectable bias for the case of lake trout14,15, but considerable bias in bioenergetics model estimates of food consumption has been detected for the case of lake whitefish15,16. On the other hand, estimates of net trophic transfer efficiency estimated in the laboratory may not be applicable to the field due to a difference in feeding rates between the laboratory and the field17. Evidence from both the laboratory and the field suggest that feeding rate can influence &#947;14,17.
The methodology used in the present study for estimating &#947; in the laboratory is applicable to situations where the predator fish is fed prey fish, and the amount of prey fish eaten by the predator can be accurately tracked. To accomplish this, the experimenter must weigh all of the food before placement in the tank; and the experimenter must be able to remove all of the uneaten food from the tank, and then weigh the uneaten food. In addition, an adequate suite of mixers and blenders should be available to obtain a sufficient degree of homogenization of the samples of both predator and prey fish. Finally, the gas chromatography &#8211; mass spectrometry instrumentation used to determine the PCB congener concentrations must be capable of detecting and quantifying individual PCB congeners at relatively low concentrations.

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			<td height="21" style="height:21px;width:259px;">Silica gel</td>
			<td style="width:87px;">BDH</td>
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			<td height="52" style="height:52px;width:259px;">Internal standard solution&#160;</td>
			<td style="width:87px;">Cambridge Isotope Laboratories</td>
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			<td style="width:87px;">Agilent/ J&#38;W</td>
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laboratory estimation of net trophic transfer efficiencies of pcb congeners to lake trout (salvelinus namaycush) from its prey

獲物から魚食性魚類のポリ塩化ビフェニル（PCB）同族体の正味の栄養転送効率（γ）の研究室で推定するための技術は、本明細書に記載されている。 135日間の室内実験中、当社は8実験室の水槽に保管ブローターレイクトラウト（ イワナのnamaycush）にミシガン湖で捕獲されていた（Coregonus hoyi）を供給した。ブローターはレイクトラウトのための自然な獲物である。タンク4内に、比較的高い流量が低流量が低いレイクトラウトの活性を可能にする、他の4つのタンクに使用したのに対し、レイクトラウト比較的高い活性を保証するために使用した。タンク·バイ·タンクベースでは、実験のそれぞれの日にレイクトラウトが食べた食物の量を記録した。各レイクトラウト、実験の開始時と終了時に秤量した。 8各タンクからの4〜9個のレイクトラウトは、実験の開始時に屠殺し、各タンクに残っているすべての10レイクトラウトはeuthanあった実験の終了時化された。私たちは、実験の最後にレイクトラウトに、実験開始時にレイクトラウト75 PCB同族体の濃度を決定し、bloatersで実験中レイクトラウトに供給。これらの測定に基づいて、γは、8つのタンクのそれぞれに75 PCB同族体のそれぞれについて計算した。 γは、アクティブおよび非アクティブの両方のレイクトラウト75 PCB同族体毎に算出された平均。実験は8タンク内に複製されたため、約標準誤差はγを推定することができたわけで。この種の実験の結果は、環境汚染のさまざまなシナリオの下で汚染された魚を食べた人間や野生生物への将来のリスクを予測するために、リスク評価モデルにおいて有用である。

最後のレイクトラウトの平均重量は853から1566グラム（ 表1）の範囲であった間に、最初のレイクトラウトの平均重量は694〜907グラムの範囲であったようにレイクトラウトは、実験中に成長のかなりの量を示した。 135日間の実験中レイクトラウトによって消費された食物の平均量は641から2649グラムの範囲であった。平均のPCB同族体濃度はによって0.03から29.31の範囲であった間に、...

Watch this Scientific Journal Video about Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout Salvelinus namaycush from Its Prey at JoVE.com

Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout Salvelinus namaycush from Its Prey

獲物から魚食性魚類のポリ塩化ビフェニル（PCB）同族体の正味の栄養転送効率の研究室推定のための技術が提供される。フィールドに検査結果の適用可能性を最大にするために、魚食性の魚​​は、一般的にフィールドに食べられている獲物の魚を供給する必要があります。

湖トラウトのPCB同族体の正味栄養の導入効率の実験室推定（<em&gt;イワナnamaycush</em&gt;）獲物から

A technique for laboratory estimation of net trophic transfer efficiency (&#947;) of polychlorinated biphenyl (PCB) congeners to piscivorous fish from ...

laboratory-estimation-net-trophic-transfer-efficiencies-pcb-congeners

Research

JoVE Journal

Environment

Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout (Salvelinus namaycush) from Its Prey

10.9K ビュー.  U. S. Geological Survey. 獲物から魚食性魚類のポリ塩化ビフェニル（PCB）同族体の正味の栄養転送効率の研究室推定のための技術が提供される。フィールドに検査結果の適用可能性を最大にするために、魚食性の魚​​は、一般的にフィールドに食べられている獲物の魚を供給する必要があります。 

ビデオ: Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout Salvelinus namaycush from Its Prey

Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) loading from lake sediments can account for a substantial portion of the total P load in eutrophic, and some mesotrophic, lakes. Laboratory determination of P release rates from sediment cores is one approach for determining the role of internal P loading and guiding management decisions. Two principal alternatives to experimental determination of sediment P release exist for estimating internal load: in situ measurements of changes in hypolimnetic P over time and P mass balance. The experimental approach using laboratory-based sediment incubations to quantify internal P load is a direct method, making it a valuable tool for lake management and restoration.
Laboratory incubations of sediment cores can help determine the relative importance of internal vs. external P loads, as well as be used to answer a variety of lake management and research questions. We illustrate the use of sediment core incubations to assess the effectiveness of an aluminum sulfate (alum) treatment for reducing sediment P release. Other research questions that can be investigated using this approach include the effects of sediment resuspension and bioturbation on P release.
The approach also has limitations. Assumptions must be made with respect to: extrapolating results from sediment cores to the entire lake; deciding over what time periods to measure nutrient release; and addressing possible core tube artifacts. A comprehensive dissolved oxygen monitoring strategy to assess temporal and spatial redox status in the lake provides greater confidence in annual P loads estimated from sediment core incubations.

Lake eutrophication is a water quality issue worldwide, making the need to identify and control nutrient sources critical. Laboratory determination of phosphorus release rates from sediment cores is a valuable approach for determining the role of internal phosphorus loading and guiding management decisions.

内部リン負荷の尺度として湖堆積物の研究室に決定されたリンフラックス

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) ...

環境学

A Fish-feeding Laboratory Bioassay to Assess the Antipredatory Activity of Secondary Metabolites from the Tissues of Marine Organisms

Marine chemical ecology is a young discipline, having emerged from the collaboration of natural products chemists and marine ecologists in the 1980s with the goal of examining the ecological functions of secondary metabolites from the tissues of marine organisms. The result has been a progression of protocols that have increasingly refined the ecological relevance of the experimental approach. Here we present the most up-to-date version of a fish-feeding laboratory bioassay that enables investigators to assess the antipredatory activity of secondary metabolites from the tissues of marine organisms. Organic metabolites of all polarities are exhaustively extracted from the tissue of the target organism and reconstituted at natural concentrations in a nutritionally appropriate food matrix. Experimental food pellets are presented to a generalist predator in laboratory feeding assays to assess the antipredatory activity of the extract. The procedure described herein uses the bluehead, Thalassoma bifasciatum, to test the palatability of Caribbean marine invertebrates; however, the design may be readily adapted to other systems. Results obtained using this laboratory assay are an important prelude to field experiments that rely on the feeding responses of a full complement of potential predators. Additionally, this bioassay can be used to direct the isolation of feeding-deterrent metabolites through bioassay-guided fractionation. This feeding bioassay has advanced our understanding of the factors that control the distribution and abundance of marine invertebrates on Caribbean coral reefs and may inform investigations in diverse fields of inquiry, including pharmacology, biotechnology, and evolutionary ecology.

This bioassay employs a model predatory fish to assess the presence of feeding-deterrent metabolites from organic extracts of the tissues of marine organisms at natural concentrations using a nutritionally comparable food matrix.

海洋生物の組織からの二次代謝産物のAntipredatory活性を評価するために魚の供給研究所バイオアッセイ

Marine chemical ecology is a young discipline, having emerged from the collaboration of natural products chemists and marine ecologists in the 1980s with ...

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.

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.

環境水試料から調製した次世代シーケンシングライブラリの品質を向上させるために自動化されたゲルサイズの選択

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

Removal of Trace Elements by Cupric Oxide Nanoparticles from Uranium In Situ Recovery Bleed Water and Its Effect on Cell Viability

In situ recovery (ISR) is the predominant method of uranium extraction in the United States. During ISR, uranium is leached from an ore body and extracted through ion exchange. The resultant production bleed water (PBW) contains contaminants such as arsenic and other heavy metals. Samples of PBW from an active ISR uranium facility were treated with cupric oxide nanoparticles (CuO-NPs). CuO-NP treatment of PBW reduced priority contaminants, including arsenic, selenium, uranium, and vanadium. Untreated and CuO-NP treated PBW was used as the liquid component of the cell growth media and changes in viability were determined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in human embryonic kidney (HEK 293) and human hepatocellular carcinoma (Hep G2) cells. CuO-NP treatment was associated with improved HEK and HEP cell viability. Limitations of this method include dilution of the PBW by growth media components and during osmolality adjustment as well as necessary pH adjustment. This method is limited in its wider context due to dilution effects and changes in the pH of the PBW which is traditionally slightly acidic&#160;however; this method could have a broader use assessing CuO-NP treatment in more neutral waters.

Removal of Trace Elements by Cupric Oxide Nanoparticles from Uranium In Situ Recovery Bleed Water and Its Effect on Cell Viability

Production bleed water (PBW) was treated with cupric oxide nanoparticles (CuO-NPs) and cellular toxicity was assessed in cultured human cells. The goal of this protocol was to integrate the native environmental sample into a cell culture format assessing the changes in toxicity due to CuO-NP treatment.

ウランの酸化銅ナノ粒子による微量元素の除去<em&gt;その場での</em&gt;回復ブリード水と細胞生存率への影響

In situ recovery (ISR) is the predominant method of uranium extraction in the United States. During ISR, uranium is leached from an ore body and extracted ...

Laboratory Simulation of an Iron(II)-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria

A conventional concept for the deposition of some Precambrian Banded Iron Formations (BIF) proceeds on the assumption that ferrous iron [Fe(II)] upwelling from hydrothermal sources in the Precambrian ocean was oxidized by molecular oxygen [O2] produced by cyanobacteria. The oldest BIFs, deposited prior to the Great Oxidation Event (GOE) at about 2.4 billion years (Gy) ago, could have formed by direct oxidation of Fe(II) by anoxygenic photoferrotrophs under anoxic conditions. As a method for testing the geochemical and mineralogical patterns that develop under different biological scenarios, we designed a 40 cm long vertical flow-through column to simulate an anoxic Fe(II)-rich marine upwelling system representative of an ancient ocean on a lab scale. The cylinder was packed with a porous glass bead matrix to stabilize the geochemical gradients, and liquid samples for iron quantification could be taken throughout the water column. Dissolved oxygen was detected non-invasively via optodes from the outside. Results from biotic experiments that involved upwelling fluxes of Fe(II) from the bottom, a distinct light gradient from top, and cyanobacteria present in the water column, show clear evidence for the formation of Fe(III) mineral precipitates and development of a chemocline between Fe(II) and O2. This column allows us to test hypotheses for the formation of the BIFs by culturing cyanobacteria (and in the future photoferrotrophs) under simulated marine Precambrian conditions. Furthermore we hypothesize that our column concept allows for the simulation of various chemical and physical environments &#8212; including shallow marine or lacustrine sediments.

Laboratory Simulation of an IronII-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria

We simulated a Precambrian ferruginous marine upwelling system in a lab-scale vertical flow-through column. The goal was to understand how geochemical profiles of O2 and Fe(II) evolve as cyanobacteria produce O2. The results show the establishment of a chemocline due to Fe(II) oxidation by photosynthetically produced O2.

光合成細菌の増殖を探検する鉄（II）リッチ先カンブリア時代マリン湧昇システムの実験室でのシミュレーション

A conventional concept for the deposition of some Precambrian Banded Iron Formations (BIF) proceeds on the assumption that ferrous iron [Fe(II)] upwelling ...

Development of Metarhizium anisopliae as a Mycoinsecticide: From Isolation to Field Performance

A major concern when developing commercial mycoinsecticides is the kill speed compared to that of chemical insecticides. Therefore, isolation and screening for the selection of a fast-acting, highly virulent entomopathogenic fungus are important steps. Entomopathogenic fungi, such as Metarhizium, Beauveria, and Nomurea, which act by contact, are better suited than Bacillus thuringiensis or nucleopolyhedrosis virus (NPV), which must be ingested by the insect pest. In the present work, we isolated 68 Metarhizium strains from infected insects using a soil dilution and bait method. The isolates were identified by the amplification and sequencing of the ITS1-5.8S-ITS2 and 26S rDNA region. The most virulent strain of Metarhizium anisopliae was selected based on the median lethal concentration (LC50) and time (LT50) obtained in insect bioassays against III-instar larvae of Helicoverpa armigera. The mass production of spores by the selected strain was carried out with solid-state fermentation (SSF) using rice as a substrate for 14 days. Spores were extracted from the sporulated biomass using 0.1% tween-80, and different formulations of the spores were prepared. Field trials of the formulations for the control of an H. armigera infestation in pigeon peas were carried out by randomized block design. The infestation control levels obtained with oil and aqueous formulations (78.0% and 70.9%, respectively) were better than the 63.4% obtained with chemical pesticide.

Development of Metarhizium anisopliae as a Mycoinsecticide: From Isolation to Field Performance

Here, we report the different stages involved in the knowledge-based development of an effective mycoinsecticide, including the isolation, identification, screening, and selection of the "best-fit" entomopathogenic fungus, Metarhizium anisopliae, for the control of insect pests in agriculture.

開発<em&gt; Metarhizium anisopliae</em&gt; Mycoinsecticideとして：分離から畑作まで

A major concern when developing commercial mycoinsecticides is the kill speed compared to that of chemical insecticides. Therefore, isolation and ...

Procedures of Laboratory Fumigation for Pest Control with Nitric Oxide Gas

Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. This paper provides detailed protocols for conducting NO fumigation on fresh products and procedures for residue analysis and product quality evaluation. An airtight fumigation chamber containing fresh fruit and vegetables is first flushed with nitrogen (N2) to establish an ultralow oxygen (ULO) environment followed by injection of NO. The fumigation chamber is then kept at a low temperature of 2 - 5 &#176;C for a specified time period necessary to kill a target pest to complete a fumigation treatment. At the end of a fumigation treatment, the fumigation chamber is flushed with N2 to dilute NO prior to opening the chamber to ambient air to prevent the reaction between NO and O2, which produces NO2 and may damage delicate fresh products. At different times after NO fumigation, NO2 in headspace and nitrate and nitrite in liquid samples were measured as residues. Product quality was evaluated after 2 weeks of post-treatment cold storage to determine effects of NO fumigation on product quality. Keeping&#160;O2 from reacting with NO is critical to NO fumigation and is an important part of the protocols. Measuring NO levels is challenging and a practical solution is provided. Possible protocol modifications are also suggested for measuring NO levels in the fumigation chambers as well as residues. NO fumigation has the potential to be a practical alternative to methyl bromide fumigation for postharvest pest control on fresh and stored products. This publication is intended to assist other researchers in conducting NO fumigation research for postharvest pest control and accelerating the development of NO fumigation for practical applications.

This paper describes nitric oxide (NO) fumigation protocols for postharvest pest control. Fumigation chambers are flushed with nitrogen (N2) to establish ultralow oxygen conditions before NO is injected. At the end, chambers are flushed with N2 to dilute NO before exposing products to ambient air to prevent exposure to NO2.

窒素酸化物ガスで害虫駆除のため研究所くん蒸処理の手順

Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. This paper provides detailed protocols for conducting NO fumigation on ...

Adherence of Bacteria to Plant Surfaces Measured in the Laboratory

This manuscript describes a method to measure bacterial binding to axenic plant surfaces in the light microscope and through the use of viable cell counts. Plant materials used include roots, sprouts, leaves, and cut fruits. The methods described are inexpensive, easy, and suitable for small sample sizes. Binding is measured in the laboratory and a variety of incubation media and conditions can be used. The effect of inhibitors can be determined. Situations that promote and inhibit binding can also be assessed. In some cases it is possible to distinguish whether various conditions alter binding primarily due to their effects on the plant or on the bacteria.

An easy method for measuring and characterizing bacterial adhesion to plants, particularly roots and sprouts, is described in this article.

植物実験室で測定した表面への細菌の付着

This manuscript describes a method to measure bacterial binding to axenic plant surfaces in the light microscope and through the use of viable cell ...

Ecosystem Fabrication (EcoFAB) Protocols for The Construction of Laboratory Ecosystems Designed to Study Plant-microbe Interactions

Beneficial plant-microbe interactions offer a sustainable biological solution with the potential to boost low-input food and bioenergy production. A better mechanistic understanding of these complex plant-microbe interactions will be crucial to improving plant production as well as performing basic ecological studies investigating plant-soil-microbe interactions. Here, a detailed description for ecosystem fabrication is presented, using widely available 3D printing technologies, to create controlled laboratory habitats (EcoFABs) for mechanistic studies of plant-microbe interactions within specific environmental conditions. Two sizes of EcoFABs are described that are suited for the investigation of microbial interactions with various plant species, including Arabidopsis thaliana, Brachypodium distachyon, and Panicum virgatum. These flow-through devices allow for controlled manipulation and sampling of root microbiomes, root chemistry as well as imaging of root morphology and microbial localization. This protocol includes the details for maintaining sterile conditions inside EcoFABs and mounting independent LED light systems onto EcoFABs. Detailed methods for addition of different forms of media, including soils, sand, and liquid growth media coupled to the characterization of these systems using imaging and metabolomics are described. Together, these systems enable dynamic and detailed investigation of plant and plant-microbial consortia including the manipulation of microbiome composition (including mutants), the monitoring of plant growth, root morphology, exudate composition, and microbial localization under controlled environmental conditions. We anticipate that these detailed protocols will serve as an important starting point for other researchers, ideally helping create standardized experimental systems for investigating plant-microbe interactions.

Ecosystem Fabrication EcoFAB Protocols for The Construction of Laboratory Ecosystems Designed to Study Plant-microbe Interactions

This article describes detailed protocols for ecosystem fabrication of devices (EcoFABs) that enable the studies of plants and plant-microbe interactions in highly controlled laboratory conditions.

植物と微生物の相互作用を調査するように設計研究所生態系の建設のため生態系製造 (EcoFAB) のプロトコル

Beneficial plant-microbe interactions offer a sustainable biological solution with the potential to boost low-input food and bioenergy production. A ...

Laboratory and Field Protocol for Estimating Sheet Erosion Rates from Dendrogeomorphology

Sheet erosion is among the crucial drivers of soil degradation. Erosion is controlled by environmental factors and human activities, which often lead to severe environmental impacts. The understanding of sheet erosion is, consequently, a worldwide issue with implications for both environment and economies. However, the knowledge on how erosion evolves in space and time is still limited, as well as its effects on the environment. Below, we explain a new dendrogeomorphological protocol for deriving eroded soil thickness (Ex) by acquiring accurate microtopographic data using both terrestrial laser scanning (TLS) and microtopographic profile gauges. Additionally, standard dendrogeomorphic procedures, dependent on anatomical variations in root rings, are utilized to establish the timing of exposure. Both TLS and microtopographic profile gauges are used to obtain ground surface pro&#64257;les, from which Ex is estimated after the threshold distance (TD) is determined, i.e., the distance between the root and the sediment knickpoint, which allows de&#64257;ning the lowering of the ground surface caused by sheet erosion. For each profile, we measured the height between the topside of the root and a virtual plane tangential to the ground surface. In this way, we intended to avoid small-scale impacts of soil deformation, which may be due to pressures exerted by the root system, or by the arrangement of exposed roots. This may provoke small amounts of soil sedimentation or erosion depending on how they physically affect the surface runoff. We demonstrate that an adequate microtopographic characterization of exposed roots and their associated ground surface is very valuable to obtain accurate erosion rates. This finding could be utilized to develop the best management practices designed to eventually halt or perhaps, at least, lessen soil erosion, so that more sustainable management policies can be put into practice.

Characterizing erosion from dendrogeomorphology has usually focused on accurately finding the starting time of root exposure, by examining macroscopic or cell level changes caused by exposure. Here, we offer a detailed description of different novel techniques to obtain more precise erosion rates from highly accurate microtopographic data.

実験室およびフィールド プロトコル Dendrogeomorphology からシート侵食速度の推定

Sheet erosion is among the crucial drivers of soil degradation. Erosion is controlled by environmental factors and human activities, which often lead to ...