Group 1 4B5AglibutArandiaAmisolaBaladadLantin

EXPERIMENT 2 SIMULATING THE ENVIRONMENT

WITH WINOGRADSKY COLUMN

• By Sergei Nikolaevitch Winogradsky – founder of soil microbiology.

• tool for microbial soil activity, nutrient cycling, microbial succession and ecology.

• Used to study carbon, nitrogen, sulfur, phosphorous and etc.

2 gradientsA. Aerobic/ Anaerobic gradientB. Sulfide gradient*promotes the growth of microorganisms

WINOGRADSKY COLUMN

• Shredded newspaper – source of carbon in cellulose form• Egg shell – contains calcium carbonate - yields carbon• Egg yolk – source of sulfur

WINOGRADSKY COLUMN

Composition A. Transparent cylinderB. Marine or freshwater mud (diverse community of interdependent microorganisms)C. Substrates to support bacterial growth

* For six to eight weeks

• Sulfide – diffuses upward• Oxygen – diffuses downward

Sulfur oxidizing organisms• Consume both where they

meet• Stable counter balance of

sulfide and oxygen gradients

• Allows organisms to grow

WINOGRADSKY COLUMN

Figure 1

MATERIALS

• Mud/soil sample

• Pond water sample• 2L clear soda bottle• 1 hard boiled egg• Shredded newspaper• Iron nail/ screw• ½ gallon empty ice cream

container

• Parafilm/plastic/cling wrap• Rubber band • Marker• Light source

METHODOLOGY

A. Winogradsky column preparation

Slice neck of 2L soda bottle, separate top from bottom column

Mark column in ml or cm

METHODOLOGY

B. Mud/ soil/ sediment sample Preparation

Mix 30g mud sample, 5g shredded newspaper, pounded egg yolk, and pulverized egg shell, in an empty ice cream container

Place mixture inside the soda bottle and add pond water enough to cover the surface of the mixture

METHODOLOGY

B. Mud/ soil/ sediment sample Preparation

Add additional 500ml of pond water in the mixture

Cover top with cling or plastic wrap with rubber bands making sure that no air is introduced

Stir to release any trapped air bubbles in the soil

METHODOLOGY

Place set up near window where there is source of natural/ artificial light

Observe weekly (for the next 6 weeks) record data

B. Mud/ soil/ sediment sample Preparation

RESULTS

WEEK 0 WEEK 2WEEK 1

Figure 2 Figure 4Figure 3

RESULTS

WEEK 3 WEEK 5WEEK 4

Figure 5 Figure 7Figure 6

RESULTSTable 1WEE

KODOR COLOR

(of soil)CONDENSATIO

N(on plastic wrap

cover)

Crust formation in the bottle

Film on water

surface

0 No foul odor

Gray None None None

1 Sulfuric odor

Light gray Present Present Present

2 Canal Light gray and green

Present Present Present

3 Canal Light gray and green

Present Present Present

4 Canal Dark green

Present Present Present

5 Canal Black Present Present Present

6 No data No data No data No data No data

DISCUSSION

Figure 8 http://archive.bio.ed.ac.uk/jdeacon/microbes/winograd.htm

Cellulose• Initially from newspaper • Promotes rapid microbial growth• Depletes the oxygen in the water column and sediment

*Organisms that grow in anaerobic conditions are those that ferment organic matter and can perform anaerobic respiration.

Fermentation• a process in which organic compounds are degraded

incompletely.

Anaerobic • a process in which organic substrates are completely

degraded to CO2.• uses a substance other than oxygen as the terminal electron

acceptor.

DISCUSSION

Cyanobacteria and Algae• need light to survive• the green coloring observed in the column on the illuminated side

Clostridium • strictly anaerobic (vegetative cells killed by oxygen exposure)• survive as spores in aerobic conditions • degrade cellulose to glucose which is fermented to gain energy and

produce simple organic compounds

Anaerobic Bacteria • contained egg yolk • enabled by the diffusion of H2S from sediment to water column,• dark green, purple or black colorings in the column• these colorings are groups of: green sulfur bacteria, purple sulfur

bacteria and sulfate-reducing bacteria• Will be further down the column

DISCUSSION

Sulfate reducing Bacteria • eat sulfur and make hydrogen sulfide gas• H2S is eaten by green and purple sulfur bacteria • Desulfovibrio

Purple Non-sulfur bacteria• need a carbon source to thrive• contained newspaper in the column• brown coloring

Different microorganisms can be observed on the Winogradsky column and that the distribution of the aerobic and anaerobic bacteria depend on the presence of oxygen and sunlight in the set-up. Aerobic bacteria such as cyanobacteria and algae reside on upper portion were oxygen and amount of sunlight is present while anaerobic bacteria such as green sulfur bacteria, purple sulfur bacteria and sulfate-reducing bacteria reside on the lower portion were scarcity of oxygen and sunlight is observed . The varying nutrient gradients and the presence of sulfur, nitrogen, carbon, and phosphorus also contribute to the distribution of the different bacteria in the Winogradsky column.

CONCLUSION