how it works..

This video describes numerous types of bacteria as they grow in a Winogradsky column.

week 3

INTRODUCTION 

Winogradsky column is a replica creates natural environments for bacterial growth. Some of the microbes produce metabolic by products that others require for survival. Its application is just same as pond mud contains a diverse community of interdependent microbes. On top of that, winogradsky column also creating as an ideal environment to study various nutrient cycles.However, since we are dealing with an anerobic environment we mostly examine the sulphur cycle.

In winogradsky column many organisms evolved to attain nutrients via chemosynthesis creating what we call nutrient cycles.In these cycles consumers and producers will work together to maintain homeostatic concentrations at each part of the cycle.

At each level, the different organisms process the same substances in different forms. Each by product is then will be subsequently used by a consumer at the next level. This eventually leads to the original chemical or gas being restored to the atmosphere  in its usable form. At the top of the column low O2 and high H2S are forms. Meanwhile higher O2 and H2S are is at the top.

RESULTS

From the observation, the column standing in the sun the layer or zonal appearance is difference look week by week. Most of the column presence of olive green by the chlorobium bacteria, and the growth of algae. Not all column presence of reddish colour and rusty orange colour.

Black patches in the column are due to FeS2 produced by Desulfvibrio bacteria. Black was the most abundant colour which had sulphur added, and sulphur is actually suitable for the growth of Desulfvibrio. From this experiment huge masses of Black patches can be seen appeared in the blank winogradsky column. A black layer normally began to form after green mucus like mass appeared in its stead under the mold. 

The next most abundant color is green. It appeared in those winogradsky column (blank, oil, fertilizer, and also heavy metal). The most abundant green patches is in fertilizer and heavy metal column and might be the excessive growth of algae. 

Red and orange colour appeared abundantly in oil, fertilizer and heavy metal column but not in blank column. It is possibly or probably due to the bacteria Chromatium. It uses H2S produced by Desulfvibrio,and requires light. It is not clear why Chromatium absent from the blank column.

Purple patches presence the most in the oil column. For oil column, at the top the orange masses floating in the water. The layer became even more distinct from each other week by week. 

DISCUSSION

Even just in a short period of time, typical bacteria communities will grow in the column. This means the column may have several useful applications in the investigation of bacterial requirements or the study of ecological relationships in bacterial communities. 

Winogradsky identified specific layers in this columns. Desulfvibrio close to the bottom, with Chlorobium  just above it and Chromatium just above Chlorobium. Then the rust brown complexes would be present in the watery layer. 

Some of the substances added for instance, oil, fertilizer and heavy metal  might have helping the growth of  bacteria . Heavymetals and rain may affect certain species of soil bacteria. Desulfvibrio in the column added fertilizer, it is possible that the fertilizer inhibited the growth of other species. 

Obligatory anaerobic bacteria at the bottom of the column will breakdown the cellulose into its glucose bases, further breaking them down by means of fermentation. Other bacteria might be respiring using this compounds(in the column) to reduce thesulphate from the eggs. These processes quickly deplete any remaining oxygen at the bottom of the column. Any bacteria release hydrogen sulphide as a by product of  said sulfate reduction. Therefore, causes a concentration gradient in the column between oxygen and hydrogen sulphide. The hydrogen sulphide is the picked up by photosynthetic bacteria that use sulphur asa reducer.  Finally, different bacteria might be competitors for a limited resource.

CONCLUSION

The end of the experiment the layers should became even more distinct from each other. the column  distinct layers may presence of a light very textured green layer, a darker more solid layer, a dark purple layer, a slightly lighter purple layer, a white layer, a green tinged water layer and mold growing on top. The higher green layer and the lower purple layer took up the largest combined portion of the column. 

By allowing the winogradsky column for a few weeks is significantly affect the presence or absence of different microbes or even the area covered by microbes.

REFERENCE

Deborah.B. et al. (2001). Building a winogradsky column National Aeronautics and space administration.  Accessed on 12 November 2014 from;www.mbari.org/earth/2013/resources/educator_guide.pdf.

Julia.S and et al. (2002). Early stage microbial growth in winogradsky plates an alternative to using column. Journal of Honors Lab Investigations 2(1): 25 - 30. 

Rosenberg.D and et al. (2010). Microbial growth in areas of varying aerobic and substrate conditions.

Figure 1: Winogradsky Column added with fertilizer (bottom)

Figure 2: Winogradsky column added with fertrilizer (top)

Figure 3: Winogradsky column added with oil (top)

Figure 4: Winogradsky column (oil)

Figure 5: Winogradsky column ( heavy metal)

Figure 6: Winogradsky Column (Blank)

Week 2 Observation

The most obvious colours observed in all the containers are red, green and rust-liked colour. Why there are different coloured zones? Center on Disabilities Studies (n.d.), these coloured bands came from the pigments of billions of photosynthetic bacteria grown in the different gradients of oxygen and hydrogen sulfide throughout the container. There are two different groups of microorganisms:

•          Photoautotroph- organisms that use light to incorporate inorganic carbon into cellular material.
•          Photoheterotroph- organisms that use light to transform organic carbon into cellular material.

The amount of the nutrients, oxygen and also temperature differs throughout the container. The very top of the container has access to oxygen continuously while the bottom part of the container accumulates hydrogen sulfide which is formed by microorganisms living in oxygen scarce environment. The picture below illustrates the oxygen and hydrogen sulfide gradient and the microbial zones based on their distinctive colour.

Figure 1: Winogradsky column on oxygen and hydrogen sulfide gradient and microbial zones (Center on Disability Studies (CDS), n.d.)

Figure 2: Blank container.

               Based on Figure 2, the topmost part of the container appears to be slightly green, then into the rust-liked colour and a layer of red black at the bottom layer. Based on CDS (n.d.) the colour presence is further explained in the table below

Table 1: The colour and the possible types of microorganism present in the blank container.

Colour	Zones	Type of microorganisms
Grass green	Aerobic -Oxygen rich part of the container	Algae or photosynthetic cyanobacteria. These bacteria have photosynthesis like that of plants.
Rust-liked	Microaerophilic -Oxygen scarce zone	Purple sulfur bacteria such as  Rhodospirilum and Rhodopseudomonas.
Red and black	Anaerobic -Oxygen depletion	Sulfate reducing decomposers Chromatium that changes from red to purple layer due to processing sulfates into sulphur. Other decomposer is Gallionella; that creates the black layer after processing iron.

Figure 3: Container with heavy metal (copper).

            Based on Figure 3, green colour appears at the top and then slightly rust-liked colour in the middle and red and slightly black at the bottom. Based on CDS (n.d.) the colour presence is further explained in the table below

Table 2: The colour and the possible types of microorganism present in the copper container.

Colour	Zones	Type of microorganisms
Grass green	Aerobic -Oxygen rich part of the container	Algae or photosynthetic cyanobacteria. These bacteria have photosynthesis like that of plants.
Rust-liked	Microaerophilic -Oxygen scarce zone	Purple sulfur bacteria such as  Rhodospirilum and Rhodopseudomonas.
Red and black	Anaerobic -Oxygen depletion	Sulfate reducing decomposers Chromatium that changes from red to purple layer due to processing sulfates into sulphur. Other decomposer is Gallionella; that creates the black layer after processing iron.

Figure 4: Container with fertilizer.

The container with fertilizer as the contaminant shows green colour at the top, followed by rust-liked colour , and red a little black at the bottom of the container. Based on CDS (n.d.) the colour presence is further explained in the table below

Table 3: The colour and the possible types of microorganism present in the fertilizer container.

Colour	Zones	Type of microorganisms
Grass green	Aerobic -Oxygen rich part of the container	Algae or photosynthetic cyanobacteria. These bacteria have photosynthesis like that of plants.
Rust-liked	Microaerophilic -Oxygen scarce zone	Purple sulfur bacteria such as  Rhodospirilum and Rhodopseudomonas.
Red and black	Anaerobic -Oxygen depletion	Sulfate reducing decomposers Chromatium that changes from red to purple layer due to processing sulfates into sulphur. Other decomposer is Gallionella; that creates the black layer after processing iron.

Figure 5: Container with cooking oil.

The only different result was obtained from the container with the cooking oil as the contaminant. The container shows red in colour at the top, followed by green for the next layer, then later rust-liked in colour. Based on CDS (n.d.) the colour presence is further explained in the table below

Table 4: The colour and the possible types of microorganism present in the fertilizer container.

Colour	Zones	Type of microorganisms
Red	Microaerophilic -Oxygen scarce zone	Purple sulfur bacteria such as Rhodospirilum and Rhodopseudomonas.
Green		Green sulfur bacteria such as Chlorobium. The green/olive colour indicates growing anaerobic conditions.
Red and black	Anaerobic -Oxygen depletion	Sulfate reducing decomposers Chromatium that changes from red to purple layer due to processing sulfates into sulphur. Other decomposer is Gallionella; that creates the black layer after processing iron.

References

Microbial Ecology, Center on Disability Studies, University of Hawaii,[pdf]. Available from: http://www.cds.hawaii.edu/kahana/downloads/curriculum/SectionII/Unit9/9.A.MicrobialEcology/9.A.2.MicrobialEcologyProject.pdf

The Winogradsky Column, Center on Disability Studies, University of Hawaii,[pdf]. Available from: http://www.cds.hawaii.edu/kahana/downloads/curriculum/SectionII/Unit9/9.A.MicrobialEcology/9.A.2.MicrobialEcology.pdf

Week 1 Observation

oil

A few red spots were observed. Alge bloomed inside the column.

fertilizer

In fertilizer column, a lot of alge start to grow. We are able to observe red colour area and green area.

heavy metal

blank

For heavy metal and blank column, not much changes were able to be observe.

Preparation of Winogradsky Column

In this experiment, mud samples were collected at Sungai Siput, Simpang Empat, Alor Gajah, Melaka (2.4341395,102.1831934).

The mud samples were closed tightly with plastic cover to avoid contamination during handling the sample to lab.

We mixed the mud with shredded newspapers to supply the microorganism with carbon. We also mixed it with egg yolk and shell to provide sulphur to the mud.

Then we separated it into four containers. Each container was labelled with blank, heavy metal, fertilizer and cooking oil.

Finally, all containers were closed with plastic and placed at open area to expose the containers to the sunlight.

Winogradsky Column