Name: microbial layers inside a winogradsky column
Uploaded: 2026-03-12T13:57:35.000Z
Duration: 1 min 27 s
Channel: JoVE

Una colonna di Winogradsky è un ecosistema microbico artificiale auto-organizzato per studiare la diversità microbica e il metabolismo.È costruito riempiendo un cilindro di vetro a metà con sedimenti ricchi di organici.La carta triturata viene aggiunta come fonte di carbonio, il gesso come fonte di solfato e il carbonato di calcio come tampon.La colonna è piena d'acqua ed esposta alla luce.Col tempo, nella colonna si sviluppano strati microbici distinti, creando gradienti di ossigeno e zolfo.In cima, i cianobatteri eseguono la fotosintesi ossigeno, producendo ossigeno e mantenendo la zona superiore aerobica.Sotto questo, i batteri chemolitotrofici dello zolfo utilizzano questo ossigeno per ossidare il solfuro di idrogeno.Nelle zone anossiche inferiori, batteri di zolfo viola e verde eseguono la fotosintesi anossigeno, utilizzando il solfuro di idrogeno per fissare l'anidride carbonica.Negli strati anossici più profondi, batteri anaerobi come riduttori di solfato e fermentatori riducono il solfato in solfuro di idrogeno, che diffonde verso l'alto ed è utilizzato dai batteri ossidanti dello zolfo, creando un ciclo verticale dello zolfo.

la colonna winogradsky

The Winogradsky Column

Una colonna di Winogradsky fornisce uno strumento potente per studiare l'ecologia microbica e le interazioni metaboliche in un ambiente stratificato e autosufficiente. Questo ecosistema artificiale, sviluppato da Sergei Winogradsky alla fine del XIX secolo, replica i complessi gradienti biogeochimici presenti nei sedimenti naturali, permettendo ai ricercatori di osservare la successione microbica e le interazioni nel tempo.La colonna è tipicamente assemblata in un cilindro di vetro trasparente riempito a metà con sedimenti mescolati con cellulosa (ad esempio, carta sminuzzata), carbonato di calcio e gesso. La cellulosa funge da fonte di carbonio, il carbonato di calcio funge da tampone per il pH e il gesso fornisce solfato. Lo spazio rimanente viene riempito con acqua dello stagno e la colonna viene sigillata per prevenire evaporazione e contaminazione. Viene poi posta alla luce per promuovere l'attività fotosintetica. Nel giro di poche settimane, si sviluppano gradienti chimici di ossigeno e zolfo, che favoriscono la formazione di zone microbiche distinte.Lo strato più alto, esposto alla luce e all'ossigeno, è dominato da fototrofi ossigenici come cianobatteri e alghe. Questi organismi fissano anidride carbonica usando energia luminosa, producendo ossigeno come sottoprodotto. Poco sotto, nella zona microaerofila, batteri zolfosi incolori ossidano il solfuro di idrogeno (H₂S) utilizzando l'ossigeno limitato disponibile, formando zolfo elementare (S⁰) o solfato (SO₄²⁻).Più in profondità nella colonna, dove l'ossigeno si esaurisce, i batteri non zolfo viola utilizzano la fototerotrofia, affidandosi a substrati organici e luce per la crescita. Ancora più in profondità, in condizioni strettamente anossiche, i batteri di zolfo viola e verde eseguono la fotosintesi anossigenica. Questi organismi utilizzano H₂S come donatore di elettroni e fissano CO₂, contribuendo alla produzione primaria in assenza di ossigeno.Alla base della colonna, batteri anaerobi come i batteri riduttori di solfato (ad esempio, Desulfovibrio spp.) e i fermentatori decompongono la materia organica. I riduttori di solfato utilizzano il solfato come accettore terminale di elettroni, producendo H₂S. Questo H₂S diffonde verso l'alto, fungendo da fonte di energia per batteri ossidanti e fotosintetici negli strati superiori, sostenendo così un ciclo zolfoso a circuito chiuso.La colonna di Winogradsky, attraverso la sua struttura stratificata e le interazioni dinamiche, esemplifica la complessità e l'interdipendenza degli ecosistemi microbici, fungendo da modello perspicace per la microbiologia ambientale e il ciclo biogeochimico.

La Colonna Winogradsky

A Winogradsky column provides a powerful tool for studying microbial ecology and metabolic interactions in a stratified, self-contained environment. This ...

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Education

Didattica

JoVE Core

Microbiology

Microbiologia

Unit

Unità

Microbial Ecology

Ecologia microbica

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

microbial layers inside a winogradsky column

A Winogradsky column shows how microbial layers form in a simple, sealed ecosystem. It is a clear model for studying microbial ecology and how different metabolisms interact in sediment over time.

The setup uses a transparent glass cylinder. Half of it is filled with sediment mixed with cellulose, such as shredded paper, calcium carbonate, and gypsum. The cellulose provides a carbon source. Calcium carbonate buffers pH, and gypsum supplies sulfate. The rest of the cylinder is filled with pond water, then sealed to limit evaporation and contamination.

The column is placed in light so photosynthesis can occur. Over several weeks, oxygen and sulfur gradients develop. These chemical changes create distinct microbial zones in the sediment and water column.

The top layer, which has both light and oxygen, is dominated by oxygenic phototrophs such as cyanobacteria and algae. These organisms use light to fix carbon dioxide and release oxygen as a byproduct. Just below that, in the microaerophilic zone, colorless sulfur bacteria use the small amount of oxygen available to oxidize hydrogen sulfide, or H2S. This process can produce elemental sulfur, S0, or sulfate, SO4(2−).

Deeper in the column, oxygen becomes scarce. Purple nonsulfur bacteria live here and use photoheterotrophy, which means they use light and organic substrates for growth. Still deeper, in fully anoxic zones, purple sulfur bacteria and green sulfur bacteria carry out anoxygenic photosynthesis. They use H2S as an electron donor and fix CO2 even without oxygen.

At the base of the column, anaerobic bacteria break down organic matter. Sulfate-reducing bacteria, such as Desulfovibrio species, use sulfate as a terminal electron acceptor and produce H2S. Fermenters also help decompose the material. The H2S moves upward and becomes fuel for sulfur-oxidizing and photosynthetic bacteria, which helps sustain a closed sulfur cycle in the column.

Microbial Layers Inside a Winogradsky Column

microbial-layers-inside-a-winogradsky-column

introduction to microbial ecology

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methods to assess microbial communities

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the winogradsky column

A Winogradsky column shows how microbial layers form in a simple, sealed ecosystem. It is a clear model for studying microbial ecology and how different metabolisms interact in sediment over time. The setup uses a transparent glass cylinder. Half of it is filled with sediment mixed with cellulose, such as shredded paper, calcium carbonate, and gypsum. The cellulose provides a carbon source. Calcium carbonate buffers pH, and gypsum supplies sulfate. The rest of the cylinder is filled with pond...

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key terms and concepts

Explore how a Winogradsky column forms distinct microbial layers, from oxygenic phototrophs at the top to sulfate reducers at the base.

Microbial Layers Inside a Winogradsky Column | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

microbiology

Microbial Layers Inside a Winogradsky Column

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