Name: fluorescently labeled bacteria as a tracer to reveal novel pathways of organic carbon flow in aquatic ecosystems
Uploaded: 2019-09-13T14:00:00
Description: Watch this Scientific Journal Video about Fluorescently Labeled Bacteria as a Tracer to Reveal Novel Pathways of Organic Carbon Flow in Aquatic Ecosystems at JoVE.com

Denne undersøgelse blev støttet af den tjekkiske videnskabs fond under forsknings tilskuddet 13-00243S og 19-16554S tildelt henholdsvis K. Š. og D. S. Denne artikel blev også støttet af projektet "Biomanipulation som et redskab til forbedring af vandkvaliteten i dæmnings reservoirer" (nr. CZ. 02.1.01/0,0/0,0/16_025/0007417), finansieret af den europæiske fond for regional udvikling, i det operationelle program for forskning, udvikling og uddannelse.

1. indsamling af prøver
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Opsamling af reservoir vandprøve: det første casestudie (exp i; lavere naturlige in situ rovdyr og Prey overflod system)<ol>
<li>Saml vandprøver fra det ønskede sted i en passende dybde. Opbevar prøverne i en temperaturkontrolleret køler, der er fyldt ved in situ-temperatur (undgå temperaturchok; det skal bemærkes, at optagelses graden for protisterne er temperaturafhængig) under transporten til laboratoriet. Bemærk: vores prøveudtagning blev udført i de...

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B., Finlay, J., Kuuppo-Leinikki, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protozoan+control+of+bacterial+abundances+in+freshwaters.">Protozoan control of bacterial abundances in freshwaters.</a> Limnology and Oceanography. 36, 139-147 (1991).</li><li>Sherr, E. B., Sherr, B. F., Kemp, P. F., Sherr, B. F., Sherr, E. B., Cole, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protistan+grazing+rates+via+uptake+of+fluorescently+labeled+prey.">Protistan grazing rates via uptake of fluorescently labeled prey.</a> Handbook of Methods in Aquatic Microbial Ecology. , 695-701 (1993).</li><li>Vazquez-Dominguez, E., Peters, F., Gasol, J. M., Vaqu&#233;, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+the+grazing+losses+of+picoplankton:+methodological+improvements+in+the+use+of+fluorescently+tracers+combined+with+flow+cytometry.">Measuring the grazing losses of picoplankton: methodological improvements in the use of fluorescently tracers combined with flow cytometry.</a> Aquatic Microbial Ecology. 20, 119-128 (1999).</li><li>&#352;imek, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ecological+role+and+bacterial+grazing+of+Halteria+spp.:+Small+oligotrichs+as+dominant+pelagic+ciliate+bacterivores.">Ecological role and bacterial grazing of Halteria spp.: Small oligotrichs as dominant pelagic ciliate bacterivores.</a> Aquatic Microbial Ecology. 22, 43-56 (2000).</li><li>Montagnes, D. J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+feeding+behaviour+of+key+free-living+protists:+avenues+for+continued+study.">Selective feeding behaviour of key free-living protists: avenues for continued study.</a> Aquatic Microbial Ecology. 53, 83-98 (2008).</li><li>Kirchman, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Processes in Microbial Ecology. 2nd Edition. , (2018).</li><li>Porter, K. G., Feig, Y. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+DAPI+for+identifying+and+counting+aquatic+microflora.">The use of DAPI for identifying and counting aquatic microflora.</a> Limnology and Oceanography. 25, 943-948 (1980).</li><li>Foissner, W., Berger, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+user-friendly+guide+to+the+ciliates+(Protozoa,+Ciliophora)+commonly+used+by+hydrobiologists+as+bioindicators+in+rivers,+lakes,+and+waste+waters,+with+notes+on+their+ecology.">A user-friendly guide to the ciliates (Protozoa, Ciliophora) commonly used by hydrobiologists as bioindicators in rivers, lakes, and waste waters, with notes on their ecology.</a> Freshwater Biology. 35, 375-482 (1996).</li><li>Foissner, W., Berger, H., Schaumburg, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+ecology+of+limnetic+plankton+ciliates.">Identification and ecology of limnetic plankton ciliates.</a> Informationsberichte des Bayer Landesamtes f&#252;r Wasserwirtschaft Heft. , 3-99 (1999).</li><li>&#352;imek, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ciliate+grazing+on+picoplankton+in+a+eutrophic+reservoir+during+the+summer+phytoplankton+maximum:+a+study+at+the+species+and+community+level.">Ciliate grazing on picoplankton in a eutrophic reservoir during the summer phytoplankton maximum: a study at the species and community level.</a> Limnology &amp; Oceanography. 40, 1077-1090 (1995).</li><li>Skibbe, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+improved+quantitative+protargol+stain+for+ciliates+and+other+planktonic+protists.">An improved quantitative protargol stain for ciliates and other planktonic protists.</a> Archiv f&#252;r. Hydrobiolgie. 130, 339-347 (1994).</li><li>Macek, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+rates+of+dominant+planktonic+ciliates+in+two+freshwater+bodies+of+different+trophic+degree.">Growth rates of dominant planktonic ciliates in two freshwater bodies of different trophic degree.</a> Journal of Plankton Research. 18, 463-481 (1996).</li><li>Šimek, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microbial+food+webs+in+hypertrophic+fishponds:+omnivorous+ciliate+taxa+are+major+protistan+bacterivores.">Microbial food webs in hypertrophic fishponds: omnivorous ciliate taxa are major protistan bacterivores.</a> Limnology &amp; Oceanography. , (2019).</li><li>Jezbera, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Major+freshwater+bacterioplankton+groups:+Contrasting+trends+in+distribution+of+Limnohabitans+and+Polynucleobacter+lineages+along+a+pH+gradient+of+72+habitats.">Major freshwater bacterioplankton groups: Contrasting trends in distribution of Limnohabitans and Polynucleobacter lineages along a pH gradient of 72 habitats.</a> FEMS Microbiology Ecology. 81, 467-479 (2012).</li><li>Kasalick&#253;, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+diversity+of+the+Limnohabitans+genus,+an+important+group+of+freshwater+bacterioplankton,+by+characterization+of+35+isolated+strains.">The diversity of the Limnohabitans genus, an important group of freshwater bacterioplankton, by characterization of 35 isolated strains.</a> PLoS One. 8, 58209 (2013).</li><li>Stabell, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ciliate+bacterivory+in+epilimnetic+waters.">Ciliate bacterivory in epilimnetic waters.</a> Aquatic Microbial Ecology. 10, 265-272 (1996).</li><li>Zingel, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ciliates+are+the+dominant+grazers+on+pico-+and+nanoplankton+in+a+shallow,+naturally+highly+eutrophic+lake.">Ciliates are the dominant grazers on pico- and nanoplankton in a shallow, naturally highly eutrophic lake.</a> Microbial Ecology. 53, 134-142 (2007).</li><li>Bickel, S. L., Tang, K. W., Grossart, H. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ciliate+epibionts+associated+with+crustacean+zooplankton+in+german+lakes:+distribution,+motility,+and+bacterivory.">Ciliate epibionts associated with crustacean zooplankton in german lakes: distribution, motility, and bacterivory.</a> Frontiers in Microbiology. 3 (243), (2012).</li><li>Sirov&#225;, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hunters+or+gardeners?+Linking+community+structure+and+function+of+trap-associated+microbes+to+the+nutrient+acquisition+strategy+of+a+carnivorous+plant.">Hunters or gardeners? Linking community structure and function of trap-associated microbes to the nutrient acquisition strategy of a carnivorous plant.</a> Microbiome. 6, 225 (2018).</li><li>&#352;imek, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ecological+traits+of+a+zoochlorellae-bearing+Tetrahymena+sp.+(Ciliophora)+living+in+traps+of+the+carnivorous+aquatic+plant+Utricularia+reflexa.">Ecological traits of a zoochlorellae-bearing Tetrahymena sp. (Ciliophora) living in traps of the carnivorous aquatic plant Utricularia reflexa.</a> Journal of Eukaryotic Microbiology. 64, 336-348 (2017).</li><li>Pitsch, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+green+Tetrahymena+utriculariae+n.+sp.+(Ciliophora,+Oligohymenophorea)+with+its+endosymbiotic+algae+(Micractinium+sp.),+living+in+the+feeding+traps+of+a+carnivorous+aquatic+plant.">The green Tetrahymena utriculariae n. sp. (Ciliophora, Oligohymenophorea) with its endosymbiotic algae (Micractinium sp.), living in the feeding traps of a carnivorous aquatic plant.</a> Journal of Eukaryotic Microbiology. 64, 322-335 (2017).</li><li>Nielsen, J. M., Clare, E. L., Hayden, B., Brett, M. T., Kratina, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diet+tracing+in+ecology:+Method+comparison+and+selection.">Diet tracing in ecology: Method comparison and selection.</a> Methods in Ecology and Evaluation. 9, 278-291 (2018).</li><li>Beisner, B. E., Grossart, H. P., Gasol, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+guide+to+methods+for+estimating+phago-mixotrophy+in+nanophytoplankton.">A guide to methods for estimating phago-mixotrophy in nanophytoplankton.</a> Journal of Plankton Research. , 1-13 (2019).</li><li>Dolan, J. D., &#352;imek, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Processing+of+ingested+matter+in+Strombidium+sulcatum,+a+marine+ciliate+(Oligotrichida).">Processing of ingested matter in Strombidium sulcatum, a marine ciliate (Oligotrichida).</a> Limnology and Oceanography. 42, 393-397 (1997).</li><li>Massana, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Grazing+rates+and+functional+diversity+of+uncultured+heterotrophic+flagellates.">Grazing rates and functional diversity of uncultured heterotrophic flagellates.</a> The ISME Journal. 3, 588-596 (2009).</li><li>Gruj&#269;i&#263;, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cryptophyta+as+major+freshwater+bacterivores+in+experiments+with+manipulated+bacterial+prey.">Cryptophyta as major freshwater bacterivores in experiments with manipulated bacterial prey.</a> The ISME Journal. 12, 1668-1681 (2018).</li></ol>

Decifrere trofiske interaktion i akvatiske systemer er altid udfordrende28, især på nano-plankton skalaer involverer protister og deres bytte, bakterier. Når det kommer til optagelse af næringsstoffer og kvantificering, er anvendelsen af metoder med succes anvendt ved højere trofiske niveauer mindre mulig på grund af den høje kompleksitet af biotiske interaktioner. Disse omfatter for eksempel stabile isotop mærkningsmetoder. Denne protokol viser fordelene ved at bruge epifluorescens mikros...

Heterotrofisk prokaryoter er en vigtig biologisk komponent i akvatiske systemer og tegner en betydelig del af plankton biomassen1,2,3. Faktorer, der styrer deres overflod, mangfoldighed og aktivitet er afgørende for at forstå deres rolle i biogeokemiske cykling (dvs. skæbne organisk kulstof og andre næringsstoffer og strømmen af energi fra prokaryoter til højere trofiske niveauer). Protozoer græsning er en af disse vigtige faktorer. Bakterien af heterotrofisk nanoflagellater og ciliater pålægger en stærk top-down kontrol over prokaryote tæthed, samfund funktion, struktur, mangfoldighed, og selv cellulære morfologi og vækstrate af bestemte bakterie grupper4, 5,6. I nogle systemer, protister tjene som den vigtigste årsag til bakteriel dødelighed6,7.
Den standardtilgang, der anvendes til at vurdere protozo bakterivory, som har været brugt i nogen tid nu, indebærer brug af fluorescently mærkede bakterier (FLB) som bytte analoger og epifluorescens mikroskopi. Celle specifikke optagelses rater kan bestemmes ved at kvantificere antallet af mærkede bytte partikler i protistan Food vakuoler over et valgt tidsforløb8. Der er flere fordele ved denne fremgangsmåde. Tracer tilsættes til naturlige prøver med naturlige rovdyr og bytte assemblages. Der er minimal prøve manipulation før inkubation, minimal stikprøve ændring af den tilføjede FLB-Tracer, og inkubationstiderne er korte for at sikre sunde resultater opnået under tæt på in situ-betingelser. Alternativt kan der i miljøer med et lavt antal bakteriæske protister eller zooplankton (f. eks. offshore marine systemer) påvises forsvinden af FLB til prøver i lave mængder (2%-3% Tracer) via flowcytometri på lang sigt (12-24 h) inkubations eksperimenter. Derefter kvantificeres antallet af FLB ved start-og slutpunkterne (integrering af virkningen af alle bakteriere) ved strømnings cytometri (Se tidligere publikation9) for yderligere oplysninger. En sådan parameter repræsenterer imidlertid kun samlede aggregerede bakterie rater, som ikke direkte kan henføres til nogen bestemt protistan-og zooplankton-grædende grupper eller arter.
Samlet set kan det være en udfordring at kvantificere de protistan arter-eller morfotype-specifikke bakterie dødelighed i vandmiljøet nøjagtigt og med økologisk betydning. Nogle protister er selektive græsere, og størrelsen og celle formen af den tilføjede FLB Tracer kan forvride naturlige rater af bytte indtagelse10,11. Desuden er protistan aktivitet og metabolisme meget temperaturfølsom12; Derfor skal mængden af tilsat FLB-Tracer omhyggeligt manipuleres for hver enkelt prøvetype (ikke kun baseret på den naturlige overflod, størrelse og morfologi af bakterier og fremherskende typer af bakteriædere, men også på temperatur). De fleste undersøgelser fokuserer på bulk protistan græsning aktivitet; imidlertid har bakterien af specifikke protistan arter ofte en meget højere informationsværdi og kan være at foretrække. I dette tilfælde er der behov for taksonomisk viden om de protist arter, der findes i en prøve, og forståelse af deres opførsel. Derfor er der behov for betydelige mængder tid og arbejdskraft for at opnå solide resultater på artsspecifikke bakterie rater, der kan henføres til en bestemt protistan gruppe eller art.
På trods af disse vanskeligheder er denne fremgangsmåde stadig det mest velegnede værktøj til vurdering af protistan bakterien i naturlige omgivelser. Præsenteret her er en omfattende, nem at følge metode til at bruge FLB som en Tracer i akvatiske mikrobielle økologi undersøgelser. Alle de nævnte problematiske aspekter af tilgangen er tegnede sig for, og en forbedret arbejdsgang er beskrevet, med to eksperimenter fra kontrasterende miljøer samt kontrasterende ciliate arter som eksempler.
Det første casestudie blev udført i et epilimnetisk miljø fra det mesotrofe římov vandreservoir i Tjekkiet, som viser græs og bakterielle mængder, der kan sammenlignes med de fleste overflade ferskvandsområder (jf.5,7). Det andet casestudie blev udført i det meget specifikke miljø inde i fælder af den akvatiske kødædende plante Utricularia reflekxa, som er vært for ekstremt høje antal af både græsnings mixotrofe ciliates (Tetrahymena utriculariae) og bakterieceller. Der vises beregninger af celle specifikke græsnings rater og bakterielle stående bestande i begge prøvetyper. En række økologiske fortolkninger af resultaterne drøftes derefter, og der foreslås endelig eksempler på mulige opfølgende undersøgelser.

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	<tbody>
		<tr height="19">
			<td height="19" style="height:20px;width:360px;">0.2-&#181;m pore-size filters&#160;</td>
			<td style="width:462px;">SPI supplies, https://www.2spi.com/</td>
			<td style="width:137px;">B0225-MB</td>
			<td style="width:654px;">Black, polycarbonate track etch membrane filters, diameter approprite for filtering apparatus used</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">5-(4,6-dichlorotriazin-2-yl) aminofluorescein (DTAF)</td>
			<td>Any brand</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Automatic pipettes with adjustable volumes&#160;</td>
			<td>Any brand, various sizes</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Centrifuge</td>
			<td>22 000 x g</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Cryovials</td>
			<td>Any brand, 2 mL size</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">DAPI (4&#180;,6-Diamidino-2&#180;-phenylindole dihydrochloride)</td>
			<td>Any brand&#160;</td>
			<td></td>
			<td>1 mg ml-1</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Epiflorescence microscope</td>
			<td>Magnification from 400 x up to 1000 x</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;"></td>
			<td>Filters appropriate for viewing in the DAPI and DTAF range</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;"></td>
			<td>Counting grid in one of the oculars</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Filtering apparatus</td>
			<td>Usually with a diameter of 25 mm&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Formaldehyde</td>
			<td>A brand for microscopy</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Glutaraldehyde</td>
			<td>A brand for microscopy</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Immersion oil for microscopy</td>
			<td>Specific oil with low fluorescence</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="58">
			<td height="58" style="height:58px;">Lugol&#180;s solution</td>
			<td>Any brand or see comment</td>
			<td></td>
			<td style="width:654px;">Make an alkaline Lugol&#39; solution as follows: Solution 1 - dissolve&#160; 10 g of potassium iodide in 20 ml in MQ water, then add 5 g of iodine. Solution 2 - add 5 g of sodium acetate&#160; to 50 ml of MQ water. Add the solution 2 to the solution 1 and thoroughly mix</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Methanol stabilized formalin</td>
			<td>Any brand available for microscopy purposes</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Microscope slides and cover slips</td>
			<td>Any brand produced for microscopy purposes&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:23px;">MQ water for diluting samples</td>
			<td style="width:462px;">Any brand 
			&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Phosphate-buffered saline (PBS; pH = 9)</td>
			<td>Any brand</td>
			<td></td>
			<td>0.05 M Na2HPO4-NaCl solution, adjusted to pH 9</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;">PPi-saline buffer</td>
			<td>Any brand</td>
			<td></td>
			<td style="width:654px;">0.02 M Na4P2O7-NaCl solution. Add 0.53 g Na4P2O7 to 100 ml of MQ water plus 0.85 g NaCl&#160;</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Sampling device&#160;</td>
			<td>Appropriate for obtaining representative sample&#160;</td>
			<td></td>
			<td>e.g. Friedinger sampler for lake plankton</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Sodium thiosulfate solution</td>
			<td>Any brand</td>
			<td></td>
			<td>3% solution is used in the protocol</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Sonicator</td>
			<td>Any brand</td>
			<td></td>
			<td>30 W</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Vortex</td>
			<td>Any brand allowing&#160; thorough mixing of the solutes and samples</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Water bath</td>
			<td>Any brand allowing temperature to be maintained at 60 &#176;C</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

fluorescently labeled bacteria as a tracer to reveal novel pathways of organic carbon flow in aquatic ecosystems

Elucidating trofiske interaktioner, såsom prædation og dens virkninger, er en hyppig opgave for mange forskere i økologi. Studiet af mikrobielle samfund har mange begrænsninger, og fastsættelsen af et rovdyr, bytte, og aggressiv satser er ofte vanskeligt. Præsenteret her er en optimeret metode baseret på tilsætning af fluorescently mærket bytte som en Tracer, som giver mulighed for pålidelig kvantitation af græsning satser i akvatiske aggressiv eukaryoter og skøn over overførsel af næringsstoffer til højere trofiske niveauer.

Eksempel eksperiment jeg blev kørt i římov vandreservoir (syd Bohemia, cz), som er et naturligt sted med lavere naturlige in situ rovdyr og bytte overflod. Der rapporteres repræsentative data for de altædende ciliatarter halteria grandinella, som er en rigelig og effektiv græsset af picoplankton (< 2 μm) partikler10,16,17,18 ,22</su...

Watch this Scientific Journal Video about Fluorescently Labeled Bacteria as a Tracer to Reveal Novel Pathways of Organic Carbon Flow in Aquatic Ecosystems at JoVE.com

Fluorescently Labeled Bacteria as a Tracer to Reveal Novel Pathways of Organic Carbon Flow in Aquatic Ecosystems

Præsenteret her er en protokol for en enkelt celle, epifluorescens mikroskopi-baserede teknik til at kvantificere græsnings rater i akvatiske aggressiv eukaryoter med høj præcision og taksonomisk opløsning.

Fluorescently mærkede bakterier som en Tracer til at afsløre nye veje af organisk kulstof flow i akvatiske økosystemer

Elucidating trophic interactions, such as predation and its effects, is a frequent task for many researchers in ecology. The study of microbial ...

Denne tilgang er betydelig, fordi det giver os mulighed for at visualisere og estimere kulstof- og energistrømme fra prokaryoter til højere trofiske niveauer i mikrobielle fødespind med en meget høj opløsning. Dette er den eneste teknik, der i øjeblikket er til rådighed til at bestemme, hvilke protistarter der indtager bakterier in situ, og samtidig kvantificere hastigheden af denne proces på et enkelt celleniveau. Da bakterier er de eneste signifikante mikrober, der ændrer opløst organisk kulstof til partikler af organisk kulstof, danner de involverede aktørers viden og de satser, hvormed dette sker, grundlaget for at forstå akvatiske økosystemer generelt. Vi anbefaler på det kraftigste, at forskerne bliver fortrolige med deres studiesystem, før de udfører græssende eksperimenter. Dette indebærer lys og epifluorescens af mikroskopi inspektion af prøverne, og viden om de vigtigste taxon nuværende og deres sæsonbestemte dynamik. Demonstration af proceduren vil blive Jitka Jezberov

Research

JoVE Journal

Environment

Alternative Method of Removing Otoliths from Sturgeon

Alternativ metode til at fjerne Otolither fra Sturgeon

Extracting the otoliths (ear bones) from fish that have very thick skulls can be difficult and very time consuming. The common practice of making a ...

Assessment of Labile Organic Carbon in Soil Using Sequential Fumigation Incubation Procedures

Vurdering af Labil organisk kulstof i jorden ved hjælp af Sekventiel Gasning Inkuberingsbetingelser Procedurer

Management practices and environmental changes can alter soil nutrient and carbon cycling. Soil labile organic carbon, a readily decomposable C pool, is ...

Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems

Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems

Forståelse opløste organiske stoffer Biogeokemi Gennem<em&gt; In Situ</em&gt; Næringsstof Manipulationer i Stream Ecosystems

Dissolved organic matter (DOM) is a highly diverse mixture of molecules providing one of the largest sources of energy and nutrients to stream ecosystems. ...

A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life

En Flow-through Exposure system til evaluering suspenderet sediment Virkninger på vandlevende

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended ...

Production and Measurement of Organic Particulate Matter in a Flow Tube Reactor

Produktion og måling af organiske partikler i en Flow rør reaktor

Organic particulate matter (PM) is increasingly recognized as important to the Earth's climate system as well as public health in urban regions, and the ...

Measurement of the Rheology of Crude Oil in Equilibrium with CO2 at Reservoir Conditions

Measurement of the Rheology of Crude Oil in Equilibrium with CO2 at Reservoir Conditions

Måling af rheologi af råolie i ligevægt med CO<sub&gt; 2</sub&gt; Ved reservoir betingelser

A rheometer system to measure the rheology of crude oil in equilibrium with carbon dioxide (CO2) at high temperatures and pressures is described. The ...

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

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

Økosystem fabrikation (EcoFAB) protokoller for byggeri Laboratory økosystemers designet til at studere plante-mikrobe interaktioner

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

Characterization of Aquatic Biofilms with Flow Cytometry

Karakterisering af akvatiske biofilm med flowcytometri

Biofilms are dynamic consortia of microorganism that play a key role in freshwater ecosystems. By changing their community structure, biofilms respond ...

Experimental Protocol for Examining Behavioral Response Profiles in Larval Fish: Application to the Neuro-stimulant Caffeine

Forsøgsplan for behandlingen af adfærdsmæssige reaktion profiler i larve fisk: ansøgning til Neuro-stimulerende koffein

Fish models and behaviors are increasingly used in the biomedical sciences; however, fish have long been the subject of ecological, physiological and ...

Use of Principal Components for Scaling Up Topographic Models to Map Soil Redistribution and Soil Organic Carbon

Brug af Principal komponenter for optrapning topografisk modeller til kort jord omfordeling og jordbundens organiske kulstof

Landscape topography is a critical factor affecting soil formation and plays an important role in determining soil properties on the earth surface, as it ...