Exercise 5: Chemolithotrophy: Winogradsky Columns Flashcards
How old are Bacteria and Archaea?
At least 3.5 billion years.
What are the most ancient forms of life? (2)
- Bacteria
- Archaea
How long were Bacteria and Archaea the only living things on Earth?
2 billion years.
What are some examples of microbial metabolic mechanisms? (4)
- Oxygenic photoautotrophy
- anoxygenic photoautotrophy
- chemoautotrophy
- photoheterotrophy
What role do microorganisms play in Earth’s ecosystem?
They cycle elements to make the planet habitable.
Where can microorganisms be found? (3)
- Hydrothermal vents
- acidic stomach lining;
- and other ecological niches.
A device for constructing a stratified microbial ecosystem.
Winogradsky column
How long does it take to complete the Winogradsky column activity?
6 to 8 weeks.
How often do you need to record observations for the Winogradsky column?
Once a week.
How much time does it take to set up the Winogradsky column experiment?
A couple of hours.
What is the main container used for a Winogradsky column?
4 clear 16-oz. plastic bottles.
In the activity, we used 1.5L plastic bottles
- What is used to dig a sediment sample?
- How much sediment is needed for the activity?
- trowel
- 6–10 cups.
- What is used as a carbon source in the experiment?
- What is the sulfur source in the experiment?
- Shredded newspaper
- Raw egg yolk
Where should the Winogradsky columns be placed?
In a well-lit location, undisturbed for 6–8 weeks.
Who developed the concept of Winogradsky columns?
Sergei Winogradsky
What do Winogradsky columns consist of?
Sediment and water in a clear container.
In Winogradsky columns, naturally occurring microbes establish __ based on metabolic activities.
geochemical gradients
The Winogradsky column allows you to witness the intricate relationship between __ and their __.
- microorganisms
- environment
What are the four (4) columns created for the activity?
1) Control
2) Carbon (with shredded paper)
3) Sulfur (raw egg yolk)
4) Carbon + Sulfur
Over time, the microorganisms in the mud and organic matter begin to interact with each other as well as with their environment leading to the formation of distinct zones, each characterized by a specific __.
microbial community
What penetrates the upper layers of the Winogradsky column?
- Oxygen
- light
What conditions are found in the upper layers of the Winogradsky column? What type of bacteria is suitable in this layer?
- Aerobic conditions
- photosynthetic bacteria
What conditions are found in the lower layers of the Winogradsky column?
- Anaerobic conditions with organic matter from the upper layers.
What energy sources do microorganisms in the lower layers use?
Sulfate or nitrate from organic matter.
Exposed to light, and contains photosynthetic bacteria like cyanobacteria and green sulfur bacteria.
What layer?
Layer 1
What type of bacteria use sunlight to convert CO2 into organic compounds via photosynthesis?
Give two examples
photosynthetic bacteria
Ex.: cyanobacteria and green sulfur bacteria
Why is Layer 1 green?
Due to the presence of chlorophyll.
It is an aerobic, oxygen-rich layer.
What layer?
Layer 2
The type of bacteria that grows in Layer 2 is an __ bacteria that break down __ using __.
- aerobic
- organic matter
- oxygen
Name two bacteria involved in the nitrogen cycle found in Layer 2. (2)
- Nitrosomonas sp.
- Nitrobacter sp.
It is an anaerobic layer that lacks oxygen.
What layer?
Layer 3
What processes are used by bacteria in Layer 3 to obtain energy? (2)
- Fermentation
- sulfate reduction
Name two bacteria found in Layer 3. (2)
- Desulfovibrio
- Methanobacterium
It is a sulfate-reducing layer.
What layer?
Layer 4
The bacteria in Layer 4 use as sulfate as __.
electron acceptor
What is produced by bacteria in Layer 4 that causes a distinct rotten egg smell?
Hydrogen sulfide
Name two bacteria found in Layer 4. (2)
- Desulfobacter
- Desulfotomaculum
Sediment containing organic matter and minerals.
What layer?
Layer 5
What type of bacteria are found in Layer 5?
Anaerobic bacteria (adapted to low-oxygen environments)
