Download to read offline
More Related Content
Similar to 8.2, Bio-transformation and geochemical cycle
8.2, Bio-transformation and geochemical cycle
- 1. WOLLO UNIVERSITY SCHOOL OFBIO-SCIENCE AND TECHNOLOGY DEPARTMENT OF BIOLOGY Agricultural Microbiology (BIOM6365) Nutrients Biotransformation and Geochemical Cycling By: Gedefaw Wubie Ordered By: Dr. Mussa Adal June, 2019 Dessie; Ethiopia 1
- 2. Contents ⢠Biogeochemical Cycles â˘Nitrogen Cycle ⢠Phosphorus cycle ⢠Sulfur cycle ⢠Carbon cycle 2
- 3. Biogeochemical Cycles ďśWhat isa Cycle? ⢠Cycle: Continuous movement or transfer of something. ⢠Cycling in Ecosystems: â All Matter (nutrients) continuously move between organisms and regions. â Energy continuously moves between organisms⌠3
- 4. Biogeochemical Cycles ďś Describethe flow of essential elements from the environment through living organisms and back into the environment. 4
- 5. Nitrogen cycle ⢠Whatis nitrogen? ďź The largest single source of nitrogen is in the atmosphere. ⢠Where is nitrogen found in the environment? ďź Nitrogen makes up 78% of our air! ďź Nitrogen is required for the manufacture of amino acids and nucleic acids) 5
- 6. Forms of Nitrogen â˘Urea ď CO(NH2)2 ⢠Ammonia ď NH3 (gaseous) ⢠Ammonium ď NH4 ⢠Nitrate ď NO3 ⢠Nitrite ď NO2 ⢠Atmospheric Dinitrogen ď N2 ⢠Organic N ⢠What happens to atmospheric nitrogen (N2) in the nitrogen cycle? 6
- 7. Atmospheric nitrogen isconverted to ammonia or nitrates. Ammonia (NH3) Nitrogen combines with Hydrogen to make Ammonia Nitrates (NO3) Nitrogen combines with Oxygen to make Nitrates Atmospheric Nitrogen (N2) N N N N
- 8. Why does atmosphericnitrogen need to be converted??? It is one of natureâs great ironies⌠ď Nitrogen is an essential component of DNA, RNA, and proteinsâthe building blocks of life. ď Although the majority of the air we breathe is nitrogen, most living organisms are unable to use nitrogen as it exists in the atmosphere! 8
- 9. ďś How doesatmospheric nitrogen get changed into a form that can be used by most living organisms? ďś By traveling through one of the four processes in the Nitrogen Cycle! 9 Nitrogen Cycle
- 10. By traveling throughone of the four processes in the Nitrogen Cycle! (1) Nitrogen Fixation (3) Nitrification (2) Ammonification (4) Denitrification Nitroge n Cycle
- 11. ⢠The firstprocess in the nitrogen cycle is⌠Nitrogen Fixation! What is ânitrogen fixationâ and what does it mean to say nitrogen gets âfixedâ? 11 Nitrogen Cycle (1) Nitrogen Fixation
- 12. âNitrogen Fixationâ isthe process that causes the strong two-atom nitrogen molecules found in the atmosphere to break apart so they can combine with other atoms. Nitrogen gets âfixedâ when it is combined with oxygen or hydrogen. N N N N N Oxygen Hydrogen Oxygen Hydrogen N
- 13. There are threeways that nitrogen gets âfixedâ! (a) Atmospheric Fixation (b) Industrial Fixation (c) Biological Fixation Bacteria
- 14. Atmospheric Fixation (Only 5to 8% of the Fixation Process) The enormous energy of lightning breaks nitrogen molecules apart and enables the nitrogen atoms to combine with oxygen forming nitrogen oxides (N2O). Nitrogen oxides dissolve in rain, forming nitrates. Nitrates (NO3) are carried to the ground with the rain. Lightning âfixesâ Nitrogen! Nitrogen combines with Oxygen Nitrogen oxides forms Nitrogen oxides dissolve in rain and change to nitrates Plants use nitrates to grow! (NO3) N N O (N2O)
- 15. Industrial Fixation Under greatpressure, at a temperature of 600 degrees Celcius, and with the use of a catalyst, atmospheric nitrogen (N2) and hydrogen are combined to form ammonia (NH3). Ammonia can be used as a fertilizer. Industrial Plant combines nitrogen and hydrogen Ammonia is formed Ammonia is used a fertilizer in soil (NH3) N N H N H3
- 16. Biological Fixation (where MOSTnitrogen fixing is completed) There are two types of âNitrogen Fixing Bacteriaâ Free Living Bacteria (âfixesâ 30% of N2) Symbiotic Relationship Bacteria (âfixesâ 70% of N2)
- 17. Free Living Bacteria Highlyspecialized bacteria live in the soil and have the ability to combine atmospheric nitrogen with hydrogen to make ammonia (NH3). Free-living bacteria live in soil and combine atmospheric nitrogen with hydrogen Nitrogen changes into ammonia N N H N H3 (NH3) Bacteria
- 18. Symbiotic Relationship Bacteria Bacteria livein the roots of legume family plants and provide the plants with ammonia (NH3) in exchange for the plantâs carbon and a protected home. Legume plants Roots with nodules where bacteria live Nitrogen changes into ammonia. NH3 N N
- 19. ⢠Most atmosphericnitrogen (N2) is âfixedâ and changed to ammonia (NH3). Ammonia is highly toxic to many organisms. Can plants use ammonia? 19
- 20. Very few plantscan use ammonia (NH3)⌠âŚbut, fortunately the second process Ammonification can help! (1) Nitrogen Fixation (2) Ammonification
- 21. What is ammonification? Ammonification: Bacteriadecomposers break down amino acids from dead animals and wastes into nitrogen ammonium. Bacteria decomposers break down amino acids into ammonium
- 22. ďśWhy is ammonificationnecessary? Because plants cannot use the organic forms of nitrogen that are in the soil as a result of: (1) wastes (manure and sewage) (2) compost and decomposing roots and leaves
- 23. How does ammonificationoccur? Microorganisms convert the organic nitrogen to ammonium. The ammonium is either taken up by the plants (only in a few types of plants) or is absorbed into the soil particles. Ammonium (NH4) in the soil is stored up to later be changed into inorganic nitrogen, the kind of nitrogen that most plants can use. Ammonium (NH4) is stored in soil. Bacteria converts organic nitrogen to ammonium (NH4) Ammonium (NH4) is used by some plants Bacteria
- 24. What happens toammonium (NH4) stored in the soil??? It travels through the third process of the nitrogen cycle called Nitrification! (1) Nitrogen Fixation (2) Ammonification (3) Nitrification
- 25. First we willquickly ârun throughâ a general overview of the Nitrification Process Nitrifying bacteria in the ground first combine ammonia with oxygen to form nitrites. Then another group of nitrifying bacteria convert nitrites to nitrates which green plants can absorb and use! Nitrifying bacteria in soil combine ammonia with oxygen Ammonia changes to nitrites Nitrifying bacteria in soil convert nitrites to nitrates Plants absorb nitrates and grow! Ammonia Nitrites Nitrates (NH3) (NO3) (NO2)
- 26. ďźNitrification is abiological process during which nitrifying bacteria convert toxic ammonia to less harmful nitrate. ďźNitrification aids in the decomposition of nitrogenous material and thus in the recycling of nitrogen atoms since the decontamination of organic nitrogen produces ammonia that is subsequently oxidized to nitrate by nitrification. ďźThere two bacterial species involved. Nitrosomonas sp. ďź Bacteria oxidize ammonia into nitrite, while Nitrobacter bacteria convert nitrite to nitrate, with both species utilizing the energy released by the reactions.
- 27. Cont⌠⢠Ammonia canbe used by some plants. ⢠Most nitrogen taken up by plants is converted by chemoautotrophic bacteria from ammonia, which is highly toxic to many organisms, first into nitrite (NO2 -), and then into nitrate (NO3 -). ⢠This process is called nitrification, and these bacteria are known as nitrifying bacteria. 27
- 28. ďNitrifiers such asArthrobacter (heterotroph), Aspergilliâs (heterotroph), and Nitrosomonas (autotroph) are delicate organisms and extremely susceptible to a variety of inhibitors. ďThey are extremely slow growing, unlike many bacteria that can double their numbers every hour or so. ďIn order to thrive, nitrifying bacteria need a relatively clean environment with a steady supply of ammonia and oxygen.
- 29. Nitrification is aTwo Step Process First Step: Ammonium Oxidation ďźThe microorganisms involved are called the ammonia oxidizers. Nitrosomonas is the most extensively studied and usually the most numerous in soil. Nitrosospira is an aquatic nitrifier. â˘Nitrosomonas â˘Nitrosospira â˘Nitrosococcus â˘Nitrosolobus Ammonia-Oxidizing Bacteria: ďźThese organisms are chemoautotrophs, growing with ammonia as the energy and CO2 as the main carbon source. ďź Species are distributed in a great variety of soils, oceans, brackish environments, rivers, lakes, and sewage disposal systems.
- 30. Second step: NitriteOxidation ⢠Microorganism involved: Nitrobacter ⢠These bacteria comprise a diverse group of rod, ellipsoidal, spherical, and spiral-shaped cells. ⢠At least one strain of Nitrobacter has been described that can grow by anaerobic respiration (denitrification). ⢠Nitrite-oxidizing bacteria are found in aerobic, but occasionally also in anaerobic, environments where organic matter is mineralized. ⢠They are widely distributed in soils, fresh water, brackish water, seawater, mud layers, sewage disposal systems, and inside stones of historical buildings and rocks. ⢠They are also found inside corroded bricks and on concrete surfaces such as in cooling towers and highway-automobile tunnels. 30
- 31. How does nitrogenreenter the atmosphere in the nitrogen cycle? Through the fourth process called denitrification! (1) Nitrogen Fixation (2) Nitrification (3) Ammonification (4) Denitrification
- 32. What does denitrificationdo? Denitrification converts nitrates (NO3) in the soil to atmospheric nitrogen (N2) replenishing the atmosphere. Nitrates (NO3) in Soil Nitrogen in atmosphere (N2)
- 33. denitrification process Denitrifying bacterialive deep in soil and in aquatic sediments where conditions make it difficult for them to get oxygen. The denitrifying bacteria use nitrates as an alternative to oxygen, leaving free nitrogen gas as a byproduct. They close the nitrogen cycle! Emissions from industrial combustion and gasoline engines create nitrous oxides gas (N2O). Volcano eruptions emit nitrous oxides gas (N2O). Denitrifying bacteria live deep in soil and use nitrates as an alternative to oxygen making a byproduct of nitrogen gas. Nitrogen in atmosphere closes the nitrogen cycle! (NO3) (N2)
- 34. (1) Nitrogen Fixation (3)Nitrification (2) Ammonification (4) Denitrification Nitrogen Cycle Nitrates in Soil Ammonia is converted to nitrites and nitrates. Organic nitrogen is converted to ammonium. (a) (b) (c) N2 NH3 NO3 N2O
- 35. (1) _____________ (3) ____________(2) _____________ (4) _____________ Nitrogen Cycle Nitrates in Soil Ammonia is converted to nitrites and nitrates. Organic nitrogen is converted to ammonium. (a) (b) (c) N2 NH3 NO3 N2O
- 37. Shortly: Nitrogen cycle. ďźNitrogen-fixing bacteriaconvert atmospheric nitrogen (N2) into ammonia (NH3). ďźAmmonia or ammonium in converted to nitrate (NO3) by nitrifying bacteria in the soil. ďźPlants assimilate nitrate, ammonia, or ammonium, producing protein and nucleic acids in the process; then animals eat plant proteins and produce animal proteins. ďźAmmonifying bacteria break down the nitrogen compounds of dead organisms, releasing ammonia that can be reused. ďź Nitrogen is returned to the atmosphere by denitrifying bacteria, which convert nitrate to atmospheric nitrogen.
- 38. Reservoir â atmosphere(as N2); soil (as NH4 + or ammonium, NH3 or ammonia, N02 - or nitrite, N03 - or nitrate Assimilation â plants absorb nitrogen as either NH4 + or as N03 -, animals obtain nitrogen by eating plants and other animals. The stages in the assimilation of nitrogen are as follows: Nitrogen Fixation: N2 to NH4 + by nitrogen-fixing bacteria (prokaryotes in the soil and root nodules), N2 to N03 - by lightning and UV radiation. Nitrification: NH4 + to N02 - and N02 - to N03 - by various nitrifying bacteria. Release â Denitrifying bacteria convert N03 - back to N2 (denitrification); detrivorous bacteria convert organic compounds back to NH4 + (ammonification); animals excrete NH4 + (or NH3) urea, or uric acid. 38
- 39. Summary of thenitrogen cycle 39
- 40. The sulfur cycle â˘The sulfur cycle contains both atmospheric and terrestrial processes. Within the terrestrial portion, the cycle begins with the weathering of rocks, releasing the stored sulfur. ⢠The sulfur then comes into contact with air where it is converted into sulfate (SO4). ⢠The sulfate is taken up by plants and microorganisms and is converted into organic forms; animals then consume these organic forms through foods they eat, thereby moving the sulfur through the food chain. ⢠As organisms die and decompose, some of the sulfur is again released as a sulfate and some enters the tissues of microorganisms. ⢠There are also a variety of natural sources that emit sulfur directly into the atmosphere, including volcanic eruptions, the breakdown of organic matter in swamps and tidal flats, and the evaporation of water. 40
- 41. Cont⌠⢠particles andtiny air borne droplets, sulfur also acts as a regulator of global climate. ⢠Sulfur dioxide and sulfate aerosols absorb ultraviolet radiation, creating cloud cover that cools cities and may offset global warming caused by the greenhouse effect. ⢠The actual amount of this offset is a question that researchers are attempting to answer. 41
- 42.
- 43. Chemical reaction involved â˘The chemical processes help produce hydrogen In the atmosphere. ⢠When the sulfur and the water in the atmosphere mix they make sulfuric acid which is put into the rain and put onto the earth surface 43
- 44. Organic Reservoirs ⢠Soil â˘Plants ďś We are tying to come up with cleaner ways to run factories so we put less sulfur into the atmosphere thus reducing the sulfuric acid in the rain which makes it better for the plants 44
- 45.
- 46.
- 47. Uses of phosphorus â˘key component of molecules that store energy ⢠ATP ⢠DNA and lipids ( fat and oil) ⢠Used to cell growth in the plant and animal ⢠Insufficient P results decreased crop yield. ⢠Phosphorus moves in a cycle through rocks, water, soil and sediments and organisms. ⢠Over time, rain and weathering cause rocks to release phosphate ions and other minerals. This inorganic phosphate is then distributed in soils and water. ⢠Plants uptake the inorganic P, when they die it turns to the soil. ⢠most of our phosphorus is locked up in sediments and rocks. ⢠Due to this reason there is no sufficient P in the plant or in the soil. ⢠The availability of phosphorus in soil to plants depends of several reversible pathways: Bacteria, ph and adsorption or using phosphate solublizing fertilizers 47
- 48. contâŚ. Reservoir â erosiontransfers phosphorus to water and soil; sediments and rocks that accumulate on ocean floors return to the surface as a result of uplifting by geological processes Assimilation â plants absorb inorganic PO4 3- (phosphate) from soils; animals obtain organic phosphorus when they plants and other animals Release â plants and animals release phosphorus when they decompose; animals excrete phosphorus in their waste products 48
- 49. Carbon cycle C is: Anelement The basis of life of earth Found in rocks, oceans, atmosphere carbon is required for building organic compounds Common Compounds: ⢠Carbon Dioxide (CO2) ⢠Glucose (C6H12O6) ⢠Methane (CH4) ⢠Carbon Monoxide (CO) 49
- 50. Cont⌠1. Reservoir âatmosphere (as CO2), fossil fuels (oil, coal), durable organic materials (for example: cellulose). 2. Assimilation â plants use CO2 in photosynthesis; animals consume plants. 3. Release â plants and animals release CO2 through respiration and decomposition; CO2 is released as wood and fossil fuels are burned. 50
- 51. Fossil fuels Examples Coal,Gas and Oil Source: Old, compressed, heated remains of organisms Store HUGE quantities of carbon inside the earth (until dug up). Release HUGE quantities of carbon dioxide when burned. 51
- 52. ContâŚ ďś The samecarbon atoms are used repeatedly on earth. They cycle between the earth and the atmosphere. 52
- 53. Carbonates ⢠Bicarbonate: (HCO3) âUsed as a buffer in organisms + water systems ⢠Calcium Carbonate: (CaCO3) â Compound formed from the shell-remains of aquatic organisms â Found underground and in water systems 53
- 54. Plant uses carbondioxide ďś Plants pull carbon dioxide from the atmosphere and use it to make food ââ photosynthesis. ďś The carbon becomes part of the plant (stored food). 54
- 55. Animal eat plants â˘When organisms eat plants, they take in the carbon and some of it becomes part of their own bodies. 55
- 56. Plants and animaldie ⢠When plants and animals die, most of their bodies are decomposed and carbon atoms are returned to the atmosphere. ⢠Some are not decomposed fully and end up in deposits underground (oil, coal, etc.). 56
- 57. Carbon slowly returnsto the atmosphere ⢠Carbon in rocks and underground deposits is released very slowly into the atmosphere. ⢠This process takes many years. 57
- 58. Carbon Cycle Diagram Carbonin Atmosphere Plants use carbon to make food Animals eat plants and take in carbon Plants and animals die Decomposers break down dead things, releasing carbon to atmosphere and soil Bodies not decomposed â after many years, become part of oil or coal deposits Fossil fuels are burned; carbon is returned to atmosphere Carbon slowly released from these substances returns to atmosphere
- 59. Carbon in theocean ⢠Additional carbon is stored in the ocean. ⢠Many animals pull carbon from water to use in shells, etc. ⢠Animals die and carbon substances are deposited at the bottom of the ocean. ⢠Oceans contain earthâs largest store of carbon. 59
- 60.
- 61.
- 62. The human impacts â˘Fossil fuels release carbon stores very slowly ⢠Burning anything releases more carbon into atmosphere â especially fossil fuels ⢠Increased carbon dioxide in atmosphere increases global warming ⢠Fewer plants mean less CO2 removed from atmosphere ⢠Burn less, especially fossil fuels ⢠Promote plant life, especially trees 62