Discuss the important of bacteria in biogeochemical cycle
A scavenger may eat the carcass, but its feces still contains a considerable amount of unused energy and nutrients. This last step releases raw nutrients (such as nitrogen, phosphorus, and magnesium) in a form usable to plants, which quickly incorporate the chemicals into their own cells. This process greatly increases the nutrient-load of an ecosystem, in turn allowing for greater biodiversity.
The carbon cycle includes four main reservoirs of stored carbon: as CO2 in the atmosphere; as organic compounds in living or recently dead organisms; as dissolved carbon dioxide in the oceans and other bodies of water; and as calcium carbonate in limestone and in buried organic matter (e.g. natural gas, peat, coal, and petroleum). Ultimately, the cycling of carbon through each of these reservoirs is tightly tied to living organisms.
Plants continuously extract carbon from the atmosphere and use it to form carbohydrates and sugars to build up their tissues through the process of photosynthesis. Animals consume plants and use these organic compounds in their metabolism. When plants and animals die, CO2 is formed again as the organic compounds combine with oxygen during decay. Not all of the compounds are oxidized, however, and a small fraction is transported and redeposited as sediment and trapped where it can form deposits of coal and petroleum. Carbon dioxide from the atmosphere also dissolves in oceans and other bodies of water. Aquatic plants use it for photosynthesis and many aquatic animals use it to make shells of calcium carbonate (CaCO3). The shells of dead organisms (e.g. phytoplankton or coral reefs) accumulate on the sea floor and can form limestone that is part of the sedimentary cycle. The relevant time-scales for these different processes vary over many orders of magnitude, from millions of years for the rock cycle and plate tectonics to days and even seconds for processes like photosynthesis and air-sea exchange.
CO2 is a trace gas in the earth's atmosphere that has a substantial effect on earth's heat balance by absorbing infrared radiation. This gas, like water vapor (H2O), CH4, and N2O, has a strong greenhouse effect. Life can alter the global concentration of CO2 over very short time periods. During the growing season, CO2 decreases in the atmosphere of the temperate latitudes due to the increasing sunlight and temperatures which help plants to increase their rate of carbon uptake and growth. During the winter dormant period, more CO2 enters the atmosphere than is removed by plants, and the concentration rises because plant respiration and the decay of dying plants and animals occurs faster than photosynthesis. The land mass in the northern hemisphere is greater than in the southern hemisphere, thus the global concentration of CO2 tracks the seasonality of terrestrial vegetation in the northern hemisphere.
Carbon, the key element of all life on earth, has a complicated biogeochemical cycle of great importance to global climate change. In carbon cycle, One of major cycles of chemical elements in the environment. Carbon is taken up from the atmosphere and incorporates into the tissues of plants in photosynthesis. It may then pass into the bodies of animals as the plants are eaten. During the respiration of plants, animals and organisms that brings about decomposition, carbon dioxide is returned to the atmosphere. The combustion of fossil fuels also releases carbon dioxide into the atmosphere. Bacteria is important ...
This is a preview of the whole essay
Carbon, the key element of all life on earth, has a complicated biogeochemical cycle of great importance to global climate change. In carbon cycle, One of major cycles of chemical elements in the environment. Carbon is taken up from the atmosphere and incorporates into the tissues of plants in photosynthesis. It may then pass into the bodies of animals as the plants are eaten. During the respiration of plants, animals and organisms that brings about decomposition, carbon dioxide is returned to the atmosphere. The combustion of fossil fuels also releases carbon dioxide into the atmosphere. Bacteria is important in this cycle to respiration in decomposers the dead organic matter. Bacteria also important in fossilization the cabon in fossil fuels.
Bacteria is very important in nitrogen cycle, one of the major cycles of chemicals element in the environment. Nitrogen exist in a variety of forms in natural systems and its compounds are involved in numerous biological and abiotic processes. Nitrogen, in its gaseous form of N2, makes up almost 80 percent of the atmosphere. This constitutes the major storage pool in the complex cycle of nitrogen through ecosystems. Some of this gas is converted in the soils and waters to ammonia (NH3), ammonium (NH4+), or many other nitrogen compounds. The process is known as nitrogen fixation. Biological nitrogen fixation is mediated by special nitrogen-fixing bacteria and algae. On the land, these bacteria often live on nodules on the roots of legumes where they use energy from plants to do their work. In freshwater and, possibly, in marine systems, cyanobacteria fix nitrogen. The conversion of ammonia to nitrates is performed primarily by soil living bacteria. The primary stage of nitrification, the oxidation of ammonia (NH3) is performed by bacteria such as the Nitrosomonas species, which converts ammonia to nitrites (NO2-). Other bacterial species, such as the Nitrobacter, are responsible for the oxidation of the nitrites into Processing, or fixation, is necessary to convert gaseous nitrogen into forms usable by living organisms. Some fixation occurs in lightning strikes, but most fixation is done by free-living or symbiotic bacteria. These bacteria have the nitrogenase enzyme that combines gaseous nitrogen with hydrogen to produce ammonia, which is then further converted by the bacteria to make its own organic compounds. Some nitrogen fixing bacteria, such as Rhizobium, live in the root nodules of legumes (such as peas or beans). Rhizobia are soil bacteria that fix nitrogen (diazotrophy) after becoming established inside root nodules of legumes (Fabaceae). The rhizobia can not independently fix nitrogen, and require a plant host. Although much of the nitrogen is removed when protein-rich grain or hay is harvested, significant amounts can remain in the soil for future crops. This is especially important when nitrogen fertilizer is not used, as in organic rotation schemes or some less-industrialized countries. Once nitrogen has been fixed in the soil or aquatic system, it can follow two different pathways. It can be oxidized for energy in a process called nitrification or assimilated by an organism into its biomass in a process called ammonia assimilation.Nitrates in the soil are taken up by plant roots and may then pass along food chains into animals. Decomposing bacteria convert nitrogen containing compounds especially ammonia in plant and animals wastes and dead remains back into nitrates, which are released into the soil and can again be taken up by plants. These reaction are mainly effected by the nitrifying bacteria Nitosomonas and Nitrobacter respectively. Though nitrogen is essential to all forms of life, the huge amount present in the atmosphere is not directly available to most organisms. It can, however, be assimilated by some specialized bacteria. and is thus made available to other organisms indirectly. Lightning flashes also make some nitrogen available to plants by causing the combination of atmospheric nitrogen and oxygen to form oxides of nitrogen, which enter the soil and form nitrates. Some nitrogen is returned from the soil to atmosphere by denitrifying bacteria. In nirtogen cycles, nitrogen-fixing bacteria use certain enzymes that are capable of fixing nitrogen gas into nitrates and include free bacteria in soil, symbiotic bacteria in legumes, and also cyanobacteria, or blue-green algae, in water. Cyanobacteria are a phylum of Bacteria that obtain their energy through photosynthesis. They are often referred to as blue-green algae.As soon as these blue-green bacteria evolved, they became the dominant metabolism for producing fixed carbon in the form of sugars from carbon dioxide. Cyanobacteria are now one of the largest and most important groups of bacteria on earth. Cyanobacteria are the only group of organisms that are able to reduce nitrogen and carbon in aerobic conditions, a fact that may be responsible for their evolutionary and ecological success. They are also able to use in anaerobic conditions only PS I-cyclic photophosphorylation-with electron donors other than water (hydrogen sulfide, thiosulphate, or even molecular hydrogen) just like purple photosynthetic bacteria. Furthermore, they share an archaebacterial property-the ability to reduce elemental sulfur by anaerobic respiration in the dark. Perhaps the most intriguing thing about these organisms is that their photosynthetic electron transport shares the same compartment as the components of respiratory electron transport. Actually, their plasma membrane contains only components of the respiratory chain, while the thylakoid membrane hosts both respiratory and photosynthetic electron transport. So, without cynobacteria, the nitrogen won't complete and will not reach the balance on the global scale.
Phosphorus cycle, the cycling of phosphorus between the biotic and abiotic components of the environment. Inorganic phosphates are absorbed by plants from the soils and bodies of water and eventually pass into animals through food chains. Within living organisms phosphates are built up into nucleic acids and other organic molecules. When plants and animals die, phosphates are released and returned to abiotic environment through the action of bacteria. The bacteria will act as decomposer and decomposition the dead organic matter. So if without bacteria, phosphates won't returned to abiotic environment. On a geological time scale, phosphates in aquatic environments eventually become incorporated into and form parts of rocks; through a river and lake. Phosphorus containing rocks and mined for the manufacture of fertilizers which provide an additional supply of inorganic phosphate to the abiotic environment.
And sulphur cycle, the cycling of sulfur between the biotic ( living ) and abiotic ( non living) components of the environment. Most of the sulphur in the abiotic environment is found in rocks, although a small amount is present in the atmosphere as sulfur dioxide, produced by combustion of fossil fuels. Sulphate, derived from the weathering and oxidation of rocks, is taken up by plants and incorporated into sulphur containing proteins. In this form sulphur is passed along food chains to animals. Decomposition of dead organic matter and faeces anaerobic sulphates reducing bacteria returns sulphur to the abiotic environment in the form of hydrogen sulphide. Hydrogen sulphide can be converted back to sulphate or to elemental sulphur by the action of different groups of photosynthetic and sulphide oxidizing bacteria. There is a group of bacteria utilize sulfur, sulfide or sulfate in their metabolism. Bacteria is important in sulphur cycle because bacteria plays a main role in decomposition, oxidation, and action of photosynthetic.
In the nitrogen cycle, the phosphorus cycle and the carbon cycle all depend on microorganisms in one way or another, especially bacteria. For example, nitrogen which makes up 78% of the planet's atmosphere is "indigestible" for most organisms, and the flow of nitrogen into the biosphere depends on a microbial process called fixation. Fixation is a chemical process in which atmospheric nitrogen is assimilated into organic compounds in living organisms and hence into the nitrogen cycle. Hence we can conclude that bacteria is very important in the biogeochemical cycles. Without bacteria, the biogeochemical won't involve equilibrium states, a balance in the cycling of the element between compartments.
Reference:
> Oxford, Dictionary of Biology. 5th edition.
>
