Wednesday, May 6, 2020

Winogradsky Column Discription free essay sample

Winogradsky column description Introduction The experiment of Winogradsky column is to observe microbiology interaction of microbes using pond mud. The aim of this paper is to describe structural and chemical features in Winogradsky column and to show the acknowledgement of microbial cells in Winogradsky column. Materials of experiment Pond mud Calcium sulfate Calcium carbonate Shredded paper Pond water Cylinder Aluminum foil Methods 1. Prepare pond mud 2. Add calcium sulfate and calcium carbonate 3. Add piece of paper 4. Add pond water 5. Seal top of the column 6. Put beside window Process (sequence of the reaction)The less of oxygen makes oxygen enrichment at the top as well as anaerobic condition at the bottom (O2 gradient). Clostridium and other anaerobic bacteria dominate under anaerobic conditions at the bottom. Cellulose from the paper into glucose and that would be a trigger for the bacteria (Clostridium) to take in the glucose and partially break it down by fermentation to gain energy and to produce ethanol and organic acids as by-products. We will write a custom essay sample on Winogradsky Column Discription or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page The by-products from Clostridium feed into other bacteria nearby in the deep mud of the column. Desulfovibrio bacteria use these organic molecules as carbon sources.At the interface of sulfide –containing mud and the more aerobic pond water, bacteria grow that can oxidize sulfur. An example is the filamentous bacterium Beggiatoa. In one metabolic strategy for survival, Beggiatoa uses H2S as an energy source and oxidizes it to sulphuric acid. The energy released by this process is used to fix carbon and produce organic molecules. (Perry, et al. ,  2002) In the pond water, aerobic photosynthetic microbes abound. These microbes include cyanobacteria and algae, which harvest light energy and release O2 as a by-product.With the energy from sunlight, the microbes fix CO2 and produce organic molecules. Algae and cyanobacteria appear quickly in the upper portion of the water column, where sunlight is abundant. By producing oxygen, these organisms help to keep this zone aerobic. This watery top layer contains an interesting diversity of microbes, green algae, cyanobacteria, various aerobic bacteria, fungi and protozoa. (Delia Castro Anderson and Rosalina V. Hairston 1999) The production of oxygen gas at the top of the column helps maintain the O2 gradient.Each layer of Winogradsky column supports certain types of bacteria, which come to dominate the culture in that region. From these enriched layers, organisms can be aerobic or anaerobic techniques. (Perry, et al. ,  2002) Layers of column (Up to bottom) Water layer (green to clear) Diatoms, cyanobacteria, algae Oxygen dominated mud (light brown) Aerobic sulfide oxidizing bacteria (Beggiatoa, thiobacillus thiothrix) Rust colored zone Photoheterotrophs (Rhodospirillum, Rhodopseudomonas) Purple/reddish zone Purple sulfur bacteria (Chromatium) Green zoneGreen sulfur bacteria (Chlorobium) Sulfate reducing bacteria (Desulfovibrio) An aerobic zone Anaerobic bacteria (Chrostridium) (Delia Castro Anderson and Rosalina V. Hairston 1999) Discussion (related to the questions) In the experiment, we put calcium carbonate, calcium sulfite and shredded paper. Shredded paper contains cellulose whic h enables the bacteria (Clostridium) to break it down by fermentation to gain energy. Calcium sulfite was added to make H2S gradient. The bacteria Desulfobrio use sulfite as electron receptor. Low sulfur bacteria and high sulfur bacteria make layers.Calcium carbonate was used as carbon source by sulfur bacteria. These chemical materials eventually makes cycles of them. Typically, column contains O2, H2S, CO2, ethanol, organic acids, H2SO4 and possibly other chemical compounds that consist of carbonate, sulfite and the other in pond mud. We sealed top of column and that makes O2 gradient. Desulfovibrio gains energy using organic molecules which is made by Clostridium (anaerobic bacteria) and Desulfovibrio makes H2S, so concentration of H2S would be higher at the bottom. That means there is H2S gradient in column.The sulfides are then used by anaerobic photosynthetic populations such as green sulfur, Chlorobium, and purple sulfur, Chromatium bacteria. Evidence of this is seen as purple and green patches in areas throughout the column as these phototrophs respond to gradients of light and sulfide. In nature, purple and green sulfur bacteria may be found in any fresh or marine waters as long as there is a sufficient supply of hydrogen sulfide and the water is clear enough so that light penetrates to the anoxic (anaerobic) zone. (Delia Castro Anderson and Rosalina V.

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