Sulfur appears on the earth's surface as a result of volcanic activity in the form of compounds, in addition to this, the water in some sources also contains hydrogen sulphide.Circulation of sulfur shown biological processes, which are caused by microorganisms in the decay of animal and plant remains.Upon decomposition of proteins containing amino acids comprising sulfur (cysteine, cystine, methionine), and decomposition of plant essential oils formed hydrogen sulfide and mercaptan.Hydrogen sulfide is released during the restoration of salts of sulfurous acid, sulfuric acid and sernovatistoy with the participation of sulfate-reducing bacteria, and is also involved in the sulfur cycle.
In fact, the hydrogen sulfide is not absorbed by plants, and accordingly, and animals.Hydrogen sulfide oxidizes sulfur bacteria special, resulting in the formation of sulfuric acid salts that plants absorbed very well.Synthesized by plants sulfur-containing compounds are also included in the sulfur cycle in nature.Ammonifying and sulfate-reducing bacteria are released from hydrogen sulfide.Sulfur cycle occurs, on the other hand, the sulfur bacteria by oxidizing hydrogen sulfide.
Groups
sulfur bacteria sulfur bacteria are divided into two groups: colorless and colored purple.
colorless forms are:
1) all kinds of Beggiatoa - long free- thread.Among them there are the largest of all the bacteria;
2) certain types Thiothrix - is still long filaments that are attached to underwater objects;
3) several species of single-celled bacteria - Thiophysa.
All bacteria - autotrophs.Circulation of sulfur contributes to its accumulation within the cell.In vivo sulfur bacteria are found only in places where hydrogen sulphide is produced constantly and where there is a free flow of oxygen.Movement of bacteria occurs in the bacterial plate.Circulation of sulfur bacteria in the biosphere is pushing up and down for the oxygen of the hydrogen sulfide.A layer of bacteria in the Black Sea is located at a depth of about 200 m.
oxidation of sulfur bacteria with oxygen takes place in two stages.Initially, they are oxidized to sulfur, which is deposited in the cytoplasm of cells and is used as an alternate energy material.
If the medium is not enough hydrogen sulfide is oxidized gradually to sulfuric acid, the stored sulfur.It is neutralized and bicarbonates cell is expelled in the form of sulfate salts.
sulfur cycle is complete without the participation of purple sulfur bacteria, enriched with pigment bakteriopurpurinom, giving them different shades of red, and photosynthetic pigment bacteriochlorophyll.
sulfur bacteria in nature are widespread.They live in the sulfur springs, stagnant waters, sludges, soil.Sulfur bacteria are autotrophs, assimilate carbon dioxide, using the energy that is produced by the oxidation of reduced sulfur compounds.
to colorless sulfur bacteria include thiobacteria which like Thiobacillus thioparus, Thiobacillus thiooxidans and others.In addition to hydrogen sulfide and sulfur, as they oxidize thio compounds are autotrophs, they are in salt and fresh water in the soil.
sulfur cycle is accompanied by reduction processes caused by sulfur bacteria, which are sometimes naturally reach enormous sizes.In the Black Sea at a depth of 200 m contains such a large amount of hydrogen sulfide that lives there all stops.With the accumulation of hydrogen sulfide in the soil, filled with water, can stop her plant and animal life.
sulfate-reducing bacteria to form sulfuric medicinal mud of many lakes around Pyatigorsk, estuaries and near Odessa Yevpatoria.These bacteria in the allocation of hydrogen sulphide are converted into a black mass of hydrate colloidal iron sulfide, impregnating sludge pond.Corrosion of iron is also going through their own fault, because of which the damaged sewage pipes and irrigation.
sulfur bacteria are involved in the biological wastewater treatment and are strong indicators of soil and water pollution in the settlements.
