Mark Nordhoff ajudou na concepção e implementação de conexões de tubos. Ellen Struve ajudou a seleccionar e adquirir equipamentos utilizados.

<ol>
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comunidades microbianas no oceano Pré-Cambriano eram regulados pelo, ou modificados como resultado de, a sua actividade e as prevalecentes condições geoquímicas. Ao interpretar as origens da BIF, investigadores geralmente inferir a presença ou a actividade de micro-organismos com base na sedimentology ou Geochemistry de BIF, por exemplo, Smith et ai. 23 e Johnson et ai. 24. O estudo de organismos modernos em ambientes modernos que têm análogos geoquímicos para amb...

O pré-cambriano (4,6-,541 Gy atrás) atmosfera experimentou uma acumulação gradual de fotossíntese produzido oxigênio (O 2), talvez pontuada por mudanças graduais na chamada &quot;Grande Oxidação Event&quot; (GOE) a cerca de 2,4 Gy atrás, e novamente no Neoproterozóico (1-,541 Gy atrás) como o 2 atmosférico se aproximarem dos níveis modernos 1. As cianobactérias são os restos evolucionários dos primeiros organismos capazes de fotossíntese aeróbica 2. Geoquímicos estudos evidências e modelagem apoiar o papel dos ambientes costeiros rasos em abrigar comunidades ativas de cianobactérias ou organismos capazes de fotossíntese aeróbica ou fototróficas oxigênicos, gerando oásis de oxigênio locais na superfície do oceano abaixo de um ambiente predominantemente anóxica 3-5. A deposição de formações ferríferas (BIFs) a partir de água do mar ao longo dos pontos Precambrianos de ferro (II) (Fe (II)) como um importante geoquímico Constituent da água do mar, pelo menos localmente, durante a sua deposição. Algumas das maiores BIFs são depósitos de águas profundas, formando fora da plataforma e talude continental. A quantidade de Fe depositado é incompatível a partir de um ponto de vista o equilíbrio de massa com (ou seja, resistência) de origem predominantemente continental. Portanto, grande parte da Fé devem ter sido fornecidos de alteração hidrotermal de máfica ou fundo do mar ultramafic crosta 6. As estimativas da taxa de Fe depositado popa dos ambientes costeiros são consistentes com Fe (II) fornecido à superfície do oceano através de ressurgência 7. Para que Fe para ser transportado em correntes de ressurgência, deve ter estado presente na forma reduzida, mobile - como Fe (II). O estado de oxidação de Fe média preservada em BIF é 2.4 8 e pensa-se geralmente que BIF preservar Fe depositado na forma de Fe (III), formado quando ressurgência de Fe (II) foi oxidado, possivelmente por oxigénio. Portanto, explorar Fe (II) mecanismos potenciais de oxidação ao longo environme inclinaçãonts é importante entender como BIF formado. Além disso, refinado caracterização geoquímica de sedimentos marinhos identificou que as condições ferruginosos, onde Fe (II) esteve presente em uma coluna de água anóxica, eram uma característica persistente dos oceanos em todo o pré-cambriano, e não pode ter sido limitado a apenas o tempo e lugar onde BIF foram depositados 9. Portanto, há pelo menos dois bilhões de anos de história da Terra, interfaces de redox entre Fe (II) e O 2 nos oceanos rasos eram susceptíveis comum. Numerosos estudos utilizar sites modernos que são análogos químicos e / ou biológicos de características diferentes do oceano pré-cambriano. Um bom exemplo são lagos ferruginosos, onde Fe (II) é estável e presente nas águas de superfície iluminada pelo sol, enquanto a atividade fotossintética (incluindo por cianobactérias) foi detectado 10-13. Os resultados destes estudos fornecem informações sobre as características geoquímicas e microbianas de um ico para anóxico / ferchemocline ruginous. No entanto, estes sites são geralmente fisicamente estratificada com pouca mistura vertical 14, em vez de as interfaces químicas que ocorrem em um sistema de ressurgência, e são pensados ​​para apoiar a produção mais oxigênio no tempo pré-cambriano 4. Um análogo natural para explorar o desenvolvimento de um oásis de oxigênio marinho sob uma atmosfera anóxica, e por um (II) sistema de ressurgência rico em Fe na coluna de água de superfície iluminada pelo sol não está disponível na Terra moderna. Portanto, é necessário um sistema de laboratório que podem simular uma zona de ressurgência ferruginosas e também apoiar o crescimento de cianobactérias e photoferrotrophs. A compreensão e identificação de processos microbianos e sua interação com um meio aquoso ressurgência que representa a água do mar pré-cambriano promove a compreensão e pode complementar as informações obtidas a partir do disco de rock, a fim de compreender totalmente os processos biogeoquímicos distintivas na Terra antiga. </p&gt; Para esse fim, uma coluna de escala laboratorial foi concebido em que o Fe (II) rico em meio de água do mar (pH neutro) foi bombeada para a parte inferior da coluna, e bombeado para fora a partir do topo. Iluminação foi fornecido na parte superior para criar um 4 cm de largura &quot;zona photic&quot; que apoiou o crescimento de cianobactérias no top 3 cm. Os ambientes naturais são geralmente estratificada e estabilizado por gradientes físico-químicas, como salinidade ou temperatura. A fim de estabilizar a coluna de água sobre uma escala de laboratório, o cilindro coluna foi empacotada com uma matriz de pérolas de vidro porosa que ajudou a manter o estabelecimento de padrões geoquímico que se desenvolveram durante o experimento. Um fluxo contínuo de gás N2 / CO 2, foi aplicada para lavar o espaço superior da coluna, a fim de manter uma atmosfera anóxica reflectora de um oceano antes da GOE 15. Depois de um fluxo constante de Fe (II) foi estabelecida, cianobactérias foram inoculados através da coluna, e a sua growth foi monitorizada por contagem de células em amostras retiradas através de portas de amostragem. O oxigénio foi monitorada in situ, colocando folhas optode sensíveis ao oxigénio sobre a parede interna do cilindro de coluna e as medições foram feitas com uma fibra óptica a partir de fora da coluna. Aquosa Fe especiação foi quantificada por amostras remoção dos portos de amostragem horizontal de profundidade resolvida e analisados ​​com o método Ferrozine. Os experimentos de controle abióticos e resultados demonstram uma prova de conceito - que um análogo de escala de laboratório da coluna de água antigo, mantido em isolamento da atmosfera, é realizável. Cianobactérias cresceu e produziu o oxigênio, e as reações entre Fe (II) e oxigênio foram resolúvel. Aqui, a metodologia para a concepção, preparação, montagem, execução e amostragem de tal coluna são apresentados, juntamente com os resultados de um 84 horas de execução da coluna enquanto inoculados com a cianobactéria marinha Synechococcus sp. PCC 7002.

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			<td>Widdel flask (5 L)</td>
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			<td>Glass bottles (5 L)</td>
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			<td>Y682.1</td>
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			<td>Sterile Luer Lock glass syringe, filled with cotton</td>
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			<td>carlroth.com</td>
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			<td>Luer Lock stainless steel needles (150 mm, 1.0 mm ID)</td>
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			<td>201015</td>
			<td>labor-ochs.de</td>
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			<td>Sigma</td>
			<td>433209</td>
			<td>sigmaaldrich.com</td>
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			<td>MgSO4</td>
			<td>Sigma</td>
			<td>208094</td>
			<td>sigmaaldrich.com</td>
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			<td>CaCl2</td>
			<td>Sigma</td>
			<td>C4901</td>
			<td>sigmaaldrich.com</td>
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			<td>NH4Cl</td>
			<td>Sigma</td>
			<td>A9434</td>
			<td>sigmaaldrich.com</td>
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			<td>KH2PO4</td>
			<td>Sigma</td>
			<td>P5655</td>
			<td>sigmaaldrich.com</td>
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			<td>KBr</td>
			<td>Sigma</td>
			<td>P3691</td>
			<td>sigmaaldrich.com</td>
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			<td>KCl</td>
			<td>Sigma</td>
			<td>P9541</td>
			<td>sigmaaldrich.com</td>
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			<td>Glass cylinder</td>
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			<td>Y310.1</td>
			<td>carlroth.com</td>
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			<td>Glass wool</td>
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			<td>7377.2</td>
			<td>carlroth.com</td>
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			<td>Glass beads (&#248; 0.55 - 0.7&#160;mm)</td>
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			<td>11079105</td>
			<td>biospec.com</td>
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			<td>Butyl rubber stopper (&#248; 1.2 cm)</td>
			<td></td>
			<td>271024</td>
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			<td>Petri Dish, glass (&#248; 8.0 cm)</td>
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			<td>T939.1</td>
			<td>carlroth.com</td>
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			<td>Polymers glue</td>
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			<td>OTTOSEAL S68</td>
			<td>adchem.de</td>
		</tr>
		<tr>
			<td>Optical oxygen sensor foil (for oxygen analysis, see below)</td>
			<td></td>
			<td>&#8211; on request &#8211;</td>
			<td>presens.de</td>
		</tr>
		<tr>
			<td>Rubber tubing (35 mm, 7 mm ID)</td>
			<td></td>
			<td>770350</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Luer Lock tube connector (3.0 mm, luer lock male = LLM)</td>
			<td></td>
			<td>P343.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Luer Lock tube connector (3.0 mm, luer lock female = LLF)</td>
			<td></td>
			<td>P335.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Rubber tubing (25 mm, 0.72 mm ID)</td>
			<td></td>
			<td>2600185</td>
			<td>newageindustries.com</td>
		</tr>
		<tr>
			<td>Rubber tubing (50 mm, 7 mm ID)</td>
			<td></td>
			<td>770350</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Luer Lock stainless steel needle (150 mm, 1.0 mm ID)</td>
			<td></td>
			<td>201015</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Luer Lock glass syringe (10 mL)</td>
			<td></td>
			<td>C680.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Loose cotton&#160;</td>
			<td></td>
			<td>&#8211;</td>
			<td></td>
		</tr>
		<tr>
			<td>Butyl rubber stopper (&#248; 1.75 cm)</td>
			<td></td>
			<td>271050</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Stainless steel needle (40 mm, 1.0 mm ID)</td>
			<td>Sterican</td>
			<td>4665120</td>
			<td>bbraun.de</td>
		</tr>
		<tr>
			<td>Luer Lock stainless steel needle (150 mm, 1.5 mm ID)</td>
			<td></td>
			<td>201520</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>position: Luer Lock female connector part at C.7</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Polymers glue</td>
			<td></td>
			<td>OTTOSEAL S68</td>
			<td>adchem.de</td>
		</tr>
		<tr>
			<td>Stainless steel needle (120 mm, 0.7 mm ID)</td>
			<td>Sterican</td>
			<td>4665643</td>
			<td>bbraun.de</td>
		</tr>
		<tr>
			<td>Rubber tubing (40 mm, 0.74 mm ID)</td>
			<td></td>
			<td>2600185</td>
			<td>newageindustries.com</td>
		</tr>
		<tr>
			<td>Heat shrink tubing (35 mm, 3 mm ID shrunk)</td>
			<td></td>
			<td>541458 - 62</td>
			<td>conrad.de</td>
		</tr>
		<tr>
			<td>Tube clamp</td>
			<td></td>
			<td>STHC-C-500-4</td>
			<td>tekproducts.com</td>
		</tr>
		<tr>
			<td>Luer Lock tube connector (1.0 mm, LLF)</td>
			<td></td>
			<td>P334.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Luer Lock plastic cap (LLM)</td>
			<td></td>
			<td>CT69.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Glass bottle (5 L)</td>
			<td>Rotilabo</td>
			<td>Y682.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Butyl rubber stopper (for GL45)</td>
			<td></td>
			<td>444704</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Stainless steel capillary (300 mm, 0.74 mm ID)</td>
			<td></td>
			<td>56736</td>
			<td>sigmaaldrich.com</td>
		</tr>
		<tr>
			<td>Stainless steel capillary (50 mm, 0.74 mm ID)</td>
			<td></td>
			<td>56737</td>
			<td>sigmaaldrich.com</td>
		</tr>
		<tr>
			<td>Shrink tubing (35 mm, 3 mm ID shrunk)</td>
			<td></td>
			<td>541458 - 62</td>
			<td>conrad.de</td>
		</tr>
		<tr>
			<td>Rubber tubing (100 mm, 0.74 mm ID)</td>
			<td></td>
			<td>2600185</td>
			<td>newageindustries.com</td>
		</tr>
		<tr>
			<td>Luer Lock tube connector (1.0 mm, LLF)</td>
			<td></td>
			<td>P334.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Luer Lock glass syringe (10 mL)</td>
			<td></td>
			<td>C680.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Loose cotton&#160;</td>
			<td></td>
			<td>&#8211;</td>
			<td></td>
		</tr>
		<tr>
			<td>Butyl rubber stopper (&#248; 1.75 cm)</td>
			<td></td>
			<td>271050</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Stainless Steel needle (40 mm, 0.8 mm ID)</td>
			<td>Sterican</td>
			<td>4657519</td>
			<td>bbraun.de</td>
		</tr>
		<tr>
			<td>Luer Lock glass syringe (5 mL)</td>
			<td></td>
			<td>C679.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Butyl rubber stopper (&#248; 1.75 mm)</td>
			<td></td>
			<td>271050</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Stainless steel needle (40 mm, 0.8 mm ID)</td>
			<td>Sterican</td>
			<td>4657519</td>
			<td>bbraun.de</td>
		</tr>
		<tr>
			<td>Rubber tubing (40 mm, 0.74 mm ID)</td>
			<td></td>
			<td>2600185</td>
			<td>newageindustries.com</td>
		</tr>
		<tr>
			<td>Glass bottle (2 L)</td>
			<td>Rotilabo</td>
			<td>X716.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Butyl rubber stopper (for GL45)</td>
			<td></td>
			<td>444704</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Stainless steel capillary (50 mm, 0.74 mm ID)</td>
			<td></td>
			<td>56736</td>
			<td>sigmaaldrich.com</td>
		</tr>
		<tr>
			<td>Rubber tubing (30 mm x 0.74 mm ID)</td>
			<td></td>
			<td>2600185</td>
			<td>newageindustries.com</td>
		</tr>
		<tr>
			<td>Rubber tubing (100 mm x 0.74 mm ID)</td>
			<td></td>
			<td>2600185</td>
			<td>newageindustries.com</td>
		</tr>
		<tr>
			<td>Luer Lock tube connector (1.0 mm, LLF)</td>
			<td></td>
			<td>P334.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Luer Lock 3-way connector (LLF, 2x LLM)</td>
			<td></td>
			<td>6134</td>
			<td>cadenceinc.com</td>
		</tr>
		<tr>
			<td>Light source</td>
			<td>Samsung</td>
			<td>SI-P8V151DB1US</td>
			<td>samsung.com</td>
		</tr>
		<tr>
			<td>Peristalic pump</td>
			<td>Ismatec</td>
			<td>EW-78017-35</td>
			<td>coleparmer.com</td>
		</tr>
		<tr>
			<td>Pumping tubing (0.89 mm ID)</td>
			<td></td>
			<td>EW-97628-26</td>
			<td>coleparmer.com</td>
		</tr>
		<tr>
			<td>Stainless steel capillary (200 mm, 0.74 mm ID)</td>
			<td></td>
			<td>56736</td>
			<td>sigmaaldrich.com</td>
		</tr>
		<tr>
			<td>Stainless steel capillary (400 mm, 0.74 mm ID)</td>
			<td></td>
			<td>56737</td>
			<td>sigmaaldrich.com</td>
		</tr>
		<tr>
			<td>Supel-Inert Foil (Tedlar - PFC) gas pack (10 L)</td>
			<td></td>
			<td>30240-U</td>
			<td>sigmaaldrich.com</td>
		</tr>
		<tr>
			<td>Rubber tube (30 mm, 6 mm ID)</td>
			<td></td>
			<td>770300</td>
			<td>labor-ochs.de</td>
		</tr>
		<tr>
			<td>Luer Lock tube connector (3.0 mm, LLM)</td>
			<td></td>
			<td>P343.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Luer Lock tube connector (3.0 mm, LLF)</td>
			<td></td>
			<td>P335.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Gas-tight syringe (20 mL)</td>
			<td></td>
			<td>C681.1</td>
			<td>carlroth.com</td>
		</tr>
		<tr>
			<td>Bunsen burner</td>
			<td></td>
			<td>&#8211;</td>
			<td></td>
		</tr>
		<tr>
			<td>Fiber optic oxygen meter for oxygen quantification</td>
			<td>Presens</td>
			<td>TR-FB-10-01</td>
			<td>presens.de</td>
		</tr>
		<tr>
			<td>Vacuum pump</td>
			<td></td>
			<td>&#8211;</td>
			<td></td>
		</tr>
		<tr>
			<td>Silicone glue for oxygen optodes</td>
			<td>Presens</td>
			<td>PS1</td>
			<td>presens.de</td>
		</tr>
	</tbody>
</table>

laboratory simulation of an iron(ii)-rich precambrian marine upwelling system to explore the growth of photosynthetic bacteria

Um conceito convencional para a deposição de alguns pré-cambrianas Banded Ferro Formações (BIF) parte do princípio de que o ferro ferroso [Fe (II)] ressurgência de fontes hidrotermais no oceano pré-cambriano foi oxidado pelo oxigênio molecular [O 2] produzida por cianobactérias. Os BIFs mais antigas, depositadas antes da Grande Oxidação Evento (GOE) em cerca de 2,4 bilhões de anos (Gy) atrás, poderia ter se formado por oxidação direta de Fe (II) por anoxigênicas photoferrotrophs sob condições anóxicas. Como um método para testar os padrões geoquímicos e mineralógicos que se desenvolvem em diferentes cenários biológicos, nós projetamos uma coluna de fluxo vertical, 40 cm de comprimento para simular um Fe anóxica (II) rico em representante de um oceano antigo sistema de ressurgência marinha numa escala de laboratório . O cilindro foi embalado com uma matriz de pérolas de vidro poroso para estabilizar os gradientes geoquímicos e amostras líquidas para a quantificação de ferro poderiam ser tomadas ao longo da coluna de água. O oxigénio dissolvido foidetectado de forma não invasiva através optodes a partir do exterior. Os resultados de experiências bióticos que envolvidas fluxos de ressurgência de Fe (II) a partir do fundo, um gradiente de luz distintas, de cima, e cianobactérias presente na coluna de água, mostra uma clara evidência para a formação de Fe (III) precipita minerais e desenvolvimento de um chemocline entre o Fe (II) e O 2. Esta coluna permite testar hipóteses para a formação dos BIFs por cultura de cianobactérias (e no futuro photoferrotrophs) sob condições simuladas Precambrianos marinhos. Além disso, nós supomos que o nosso conceito de coluna permite a simulação de vários ambientes químicos e físicos - incluindo marinhos ou lacustres sedimentos superficiais.

experimento controle Experimentos de controle abiótico (10 dias) demonstraram concentrações consistentemente baixos de oxigênio (O 2 &lt;0,15 mg / L) sem flutuações significativas na Fe (II) -profile ao longo da coluna de água de ressurgência. A formação de precipitados (presumivelmente Fe (III) (oxyhydr-) óxidos) no reservatório médio e a ligeira diminuição do Fe (II) co...

Watch this Scientific Journal Video about Laboratory Simulation of an IronII-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria at JoVE.com

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

Nós simulamos um sistema de ressurgência marinha ferruginoso Precambrian em uma coluna de fluxo vertical-escala de laboratório. O objetivo foi compreender perfis como geoquímicas de O2 e Fe (II) evoluir como cianobactérias produzem O 2. Os resultados mostram a criação de um chemocline devido a Fe (II) oxidação pelo fotossinteticamente O produziu 2.

Laboratório de Simulação de um ferro (II) rico em Precambrian Marinha Ressurgência do sistema para explorar o crescimento de bactérias fotossintéticas

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

laboratory-simulation-an-iron-ii-rich-precambrian-marine-upwelling

Research

JoVE Journal

Environment

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

11.7K visualizações.  University of Tuebingen.  Nós simulamos um sistema de ressurgência marinha ferruginoso Precambrian em uma coluna de fluxo vertical-escala de laboratório. O objetivo foi compreender perfis como geoquímicas de O2 e Fe (II) evoluir como cianobactérias produzem O 2. Os resultados mostram a criação de um chemocline devido a Fe (II) oxidação pelo fotossinteticamente O produziu 2. 

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

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.

A Laboratory Bioassay alimentando-Fish para avaliar a actividade anti-predação de metabolitos secundários a partir de tecidos de organismos marinhos

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

Ambiente

Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor

The importance of microbial sulfate reduction relies on the various applications that it offers in environmental biotechnology. Engineered sulfate reduction is used in industrial wastewater treatment to remove large concentrations of sulfate along with the chemical oxygen demand (COD) and heavy metals. The most common approach to the process is with anaerobic bioreactors in which sulfidogenic sludge is obtained through adaptation of predominantly methanogenic granular sludge to sulfidogenesis. This process may take a long time and does not always eliminate the competition for substrate due to the presence of methanogens in the sludge. In this work, we propose a novel approach to obtain sulfidogenic sludge in which hydrothermal vents sediments are the original source of microorganisms. The microbial community developed in the presence of sulfate and volatile fatty acids is wide enough to sustain sulfate reduction over a long period of time without exhibiting inhibition due to sulfide. 
This protocol describes the procedure to generate the sludge from the sediments in an upflow anaerobic sludge blanket (UASB) type of reactor. Furthermore, the protocol presents the procedure to demonstrate the capability of the sludge to remove by reductive dechlorination a model of a highly toxic organic pollutant such as trichloroethylene (TCE). The protocol is divided in three stages: (1) the formation of the sludge and the determination of its sulfate reducing activity in the UASB, (2) the experiment to remove the TCE by the sludge, and (3) the identification of microorganisms in the sludge after the TCE reduction. Although in this case the sediments were taken from a site located in Mexico, the generation of a sulfidogenic sludge by using this procedure may work if a different source of sediments is taken since marine sediments are a natural pool of microorganisms that may be enriched in sulfate reducing bacteria.

Microbial sulfate reduction is a process of great importance in environmental biotechnology. The success of the sulfidogenic reactors depends among other factors on the microbial composition of the sludge. Here, we present a protocol to develop sulfidogenic sludge from hydrothermal vents sediments in a UASB reactor for reductive dechlorination purposes.

Desenvolvimento de sulfidogenico Sludge de sedimentos marinhos e Redução Trichloroethylene em um Reator Anaeróbio de Manta de Lodo

The importance of microbial sulfate reduction relies on the various applications that it offers in environmental biotechnology. Engineered sulfate ...

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and detritus, and excreting particulate and dissolved compounds, they serve as important agents for benthic-pelagic coupling. Accurately measuring the compounds removed and excreted by suspension feeders (such as sponges, ascidians, polychaetes, bivalves) is crucial for the study of their physiology, metabolism, and feeding ecology, and is fundamental to determine the ecological relevance of the nutrient fluxes mediated by these organisms. However, the assessment of the rate by which suspension feeders process particulate and dissolved compounds in nature is restricted by the limitations of the currently available methodologies. Our goal was to develop a simple, reliable, and non-intrusive method that would allow clean and controlled water sampling from a specific point, such as the excurrent aperture of benthic suspension feeders, in situ. Our method allows simultaneous sampling of inhaled and exhaled water of the studied organism by using minute tubes installed on a custom-built manipulator device and carefully positioned inside the exhalant orifice of the sampled organism. Piercing a septum on the collecting vessel with a syringe needle attached to the distal end of each tube allows the external pressure to slowly force the sampled water into the vessel through the sampling tube. The slow and controlled sampling rate allows integrating the inherent patchiness in the water while ensuring contamination free sampling. We provide recommendations for the most suitable filtering devices, collection vessel, and storing procedures for the analyses of different particulate and dissolved compounds. The VacuSIP system offers a reliable method for the quantification of undisturbed suspension feeder metabolism in natural conditions that is cheap and easy to learn and apply to assess the physiology and functional role of filter feeders in different ecosystems.

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

We introduce the VacuSIP, a simple, non-intrusive, and reliable method for clean and accurate point sampling of water. The system was developed and evaluated for the simultaneous collection of the water inhaled and exhaled by benthic suspension feeders in situ, to cleanly measure removal and excretion of particulate and dissolved compounds.

VacuSIP, um método melhorado para Inex<em&gt; In Situ</em&gt; Medição de partículas e dissolvidos compostos Processado por alimentadores de suspensão ativa

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and ...

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food webs. Toxicity testing based on microorganisms are widely used because they are relatively quick, reproducible, cheap, and are not associated with ethical issues. Here, we describe an ecotoxicological method to evaluate the biological response of the marine bacterium Vibrio anguillarum. This method assesses the acute toxicity of chemical compounds, including new contaminants such as nanoparticles, as well as environmental samples. The endpoint is the reduction of bacterial culturability (i.e., the capability to replicate and form colonies) due to exposure to a toxicant. This reduction can be generally referred to as mortality. The test allows for the determination of the LC50, the concentration that causes a 50% decrease of bacteria actively replicating and forming colonies, after a 6 h exposure. The culturable bacteria are counted in terms of colony forming units (CFU), and the &#34;mortality&#34; is evaluated and compared to the control. In this work, the toxicity of copper sulphate (CuSO4) was evaluated. A clear dose-response relationship was observed, with a mean LC50 of 1.13 mg/L, after three independent tests. This protocol, compared to existing methods with microorganisms, is applicable in a wider range of salinity and has no limitations for colored/turbid samples. It uses saline solution as the exposure medium, avoiding any possible interferences of growth medium with the investigated contaminants. The LC50 calculation facilitates comparisons with other bioassays commonly applied to ecotoxicological assessments of the marine environment.

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

This work describes a new protocol to assess the ecotoxicity of pollutants, including emerging contaminants such as nanomaterials, using the marine bacterium Vibrio anguillarum. This method allows for the determination of the LC50, or mortality, the concentration that causes a 50% decrease in bacteria culturability, after a 6 h exposure.

Método Ecotoxicológico com Bactérias Marinhas<em&gt; Vibrio anguillarum</em&gt; Avaliar a Toxicidade Aguda dos Contaminantes Ambientais

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food ...

Comparison of Scale in a Photosynthetic Reactor System for Algal Remediation of Wastewater

An experimental methodology is presented to compare the performance of two different sized reactors designed for wastewater treatment. In this study, ammonia removal, nitrogen removal and algal growth are compared over an 8-week period in paired sets of small (100 L) and large (1,000 L) reactors designed for algal remediation of landfill wastewater. Contents of the small and large scale reactors were mixed before the beginning of each weekly testing interval to maintain equivalent initial conditions across the two scales. System characteristics, including surface area to volume ratio, retention time, biomass density, and wastewater feed concentrations, can be adjusted to better equalize conditions occurring at both scales. During the short 8-week representative time period, starting ammonia and total nitrogen concentrations ranged from 3.1-14 mg NH3-N/L, and 8.1-20.1 mg N/L, respectively. The performance of the treatment system was evaluated based on its ability to remove ammonia and total nitrogen and to produce algal biomass. Mean &#177; standard deviation of ammonia removal, total nitrogen removal and biomass growth rates were 0.95&#177;0.3 mg NH3-N/L/day, 0.89&#177;0.3 mg N/L/day, and 0.02&#177;0.03 g biomass/L/day, respectively. All vessels showed a positive relationship between the initial ammonia concentration and ammonia removal rate (R2=0.76). Comparison of process efficiencies and production values measured in reactors of different scale may be useful in determining if lab-scale experimental data is appropriate for prediction of commercial-scale production values.

An experimental methodology is presented to compare the performance of small (100 L) and large (1,000 L) scale reactors designed for algae remediation of landfill wastewater. System characteristics, including surface area to volume ratio, retention time, biomass density, and wastewater feed concentrations, can be adjusted based on application.

Comparação de Scale em um sistema de reactores fotossintético de algas Remediação de Águas Residuais

An experimental methodology is presented to compare the performance of two different sized reactors designed for wastewater treatment. In this study, ...

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.

Extração de Pesticidas Organoclorados de Pelotização de Plástico e Análise de Tipo de Plástico

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

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.

Aderência de bactérias para plantar superfícies medidas em laboratório

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

Development of New Methods for Quantifying Fish Density Using Underwater Stereo-video Tools

The use of video camera systems in ecological studies of fish continues to gain traction as a viable, non-extractive method of measuring fish lengths and estimating fish abundance. We developed and implemented a rotating stereo-video camera tool that covers a full 360 degrees of sampling, which maximizes sampling effort compared to stationary camera tools. A variety of studies have detailed the ability of static, stereo-camera systems to obtain highly accurate and precise measurements of fish; the focus here was on the development of methodological approaches to quantify fish density using rotating camera systems. The first approach was to develop a modification of the metric MaxN, which typically is a conservative count of the minimum number of fish observed on a given camera survey. We redefine MaxN to be the maximum number of fish observed in any given rotation of the camera system. When precautions are taken to avoid double counting, this method for MaxN may more accurately reflect true abundance than that obtained from a fixed camera. Secondly, because stereo-video allows fish to be mapped in three-dimensional space, precise estimates of the distance-from-camera can be obtained for each fish. By using the 95% percentile of the observed distance from camera to establish species-specific areas surveyed, we account for differences in detectability among species while avoiding diluting density estimates by using the maximum distance a species was observed. Accounting for this range of detectability is critical to accurately estimate fish abundances. This methodology will facilitate the integration of rotating stereo-video tools in both applied science and management contexts.

We describe a new method for counting fishes, and estimating relative abundance (MaxN) and fish density using rotating stereo-video camera systems. We also demonstrate how to use distance from camera (Z distance) to estimate species-specific detectability.

Desenvolvimento de novos métodos para quantificar a densidade de peixes usando ferramentas de estéreo-vídeo subaquáticas

The use of video camera systems in ecological studies of fish continues to gain traction as a viable, non-extractive method of measuring fish lengths and ...

The Barnacle Balanus improvisus as a Marine Model - Culturing and Gene Expression

Barnacles are marine crustaceans with a sessile adult and free-swimming, planktonic larvae. The barnacle Balanus (Amphibalanus) improvisus is particularly relevant as a model for the studies of osmoregulatory mechanisms because of its extreme tolerance to low salinity. It is also widely used as a model of settling biology, in particular in relation to antifouling research. However, natural seasonal spawning yields an unpredictable supply of cyprid larvae for studies. A protocol for the all-year-round culturing of B. improvisus has been developed and a detailed description of all steps in the production line is outlined (i.e., the establishment of adult cultures on panels, the collection and rearing of barnacle larvae, and the administration of feed for adults and larvae). The description also provides guidance on troubleshooting and discusses critical parameters (e.g., the removal of contamination, the production of high-quality feed, the manpower needed, and the importance of high-quality seawater). Each batch from the culturing system maximally yields roughly 12,000 nauplii and can deliver four batches in a week, so up to almost 50,000 larvae per week can be produced. The method used to culture B. improvisus is, probably, to a large extent also applicable to other marine invertebrates with free-swimminglarvae. Protocols are presented for the dissection of various tissues from adults as well as the production of high-quality RNA for studies on gene expression. It is also described how cultured adults and reared cyprids can be utilized in a wide array of experimental designs for examining gene expression in relation to external factors. The use of cultured barnacles in gene expression is illustrated with studies of possible osmoregulatory roles of Na+/K+ ATPase and aquaporins.

The Barnacle Balanus improvisus as a Marine Model - Culturing and Gene Expression

The barnacle Balanus (Amphibalanus) improvisus is a model for studying osmoregulation and antifouling. However, natural seasonal spawning yields an unpredictable supply of cyprid larvae. Here, a protocol for the all-year-round culturing of B. improvisus is described, including the production of larvae. The use of cultured barnacles in gene expression studies is illustrated.

A craca Balanus improvisus como modelo Marine - cultivo e expressão gênica

Barnacles are marine crustaceans with a sessile adult and free-swimming, planktonic larvae. The barnacle Balanus (Amphibalanus) improvisus is particularly ...

An Optimized Rhizobox Protocol to Visualize Root Growth and Responsiveness to Localized Nutrients

Roots are notoriously difficult to study. Soil is both a visual and mechanical barrier, making it difficult to track roots in situ without destructive harvest or expensive equipment. We present a customizable and affordable rhizobox method that allows the non-destructive visualization of root growth over time and is particularly well-suited to studying root plasticity in response to localized resource patches. The method was validated by assessing maize genotypic variation in plasticity responses to patches containing 15N-labeled legume residue. Methods are described to obtain representative developmental measurements over time, measure root length density in resource-containing and control patches, calculate root growth rates, and determine 15N recovery by plant roots and shoots. Advantages, caveats, and potential future applications of the method are also discussed. Although care must be taken to ensure that experimental conditions do not bias root growth data, the rhizobox protocol presented here yields reliable results if carried out with sufficient attention to detail.

Visualizing and measuring root growth in situ is extremely challenging. We present a customizable rhizobox method to track root development and proliferation over time in response to nutrient enrichment. This method is used to analyze maize genotypic differences in root plasticity in response to an organic nitrogen source.

Um protocolo otimizado de Rhizobox para visualizar o crescimento da raiz e receptividade aos nutrientes localizadas

Roots are notoriously difficult to study. Soil is both a visual and mechanical barrier, making it difficult to track roots in situ without destructive ...

Laboratório de Simulação de um ferro (II) rico em Precambrian Marinha Ressurgência do sistema para explorar o crescimento de bactérias fotossintéticas

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