Microorganisms & Biogeochemical Cycles

Transcription

1 Microorganisms & Biogeochemical Cycles Biogeochemical Cycles: Movement & transformation of chemical elements (nutrien) in the environment caused by biological and chemical processes in the atmosphere, hydrosphere & lithosphere Both macro and micronutrients go through biogeochemical cycles Why do biogeochemical cycles happen? What is the role of microorganisms in biogeochemical cycles? Biogeochemical cycles happen as natures effort for : Prevent accumulation of waste Maintain availability of nutrients needed by the enviroment/ecosystem The biogeochemical cycle is a global cycle impacts the geology and earth environment as a whole Naturally, the chemical elements are in a balance Human activities change/disrupt the balance of the elements (example: C cycle) 1

2 Biogeochemical Cycle 2

3 The Microorganism and Biogeochemical Cycles The role of microorganisms in nature: decomposer Microorganisms are biological agents directly involved in biogeochemical cycles Microorganisms are sources for some elements and reservoirs for other elements Interaction among microorganisms, humans and other parts in the biosphere create global problems Biological contribution on Atmosphere Composition Type of Gas Input from Removal % change N 2 Microorg (100) Microorg (53) Humans (41) O 2 Microalgae Plants Microorg, animals negligible CO 2 Microorg(86), Animals, Humans Microalgae Plants +0,4% CH 4 Microorg(26), Animals (17), Humans (57) Microorg, chemicals +1% N 2 O Microorg (50), Humans (50) Microorg (?), Chemicals (?) +0,3% 3

4 Carbon Cycle (C) & Oxygen (O) The C Cycle cannot be separated from the O cycle: CO 2 fixation Organic substance oxidation CO 2 Global transfer of C occurs in the form of CO 2 (most active reservoir) The C cycle involves activity of micro- and macroorganisms Main role of microorganisms: DECOMPOSER organic substances Global C Cycle 4

5 Main Stages of the C Cycle Photosynthesis: Organic C production by autotrophs Degradation /Decomposition: The utilization of organic C organik by microorganisms, forming: CO 2 CH 4 Microorganisms that play a role: Heterotrophic, Methanogens Disturbance of C Cycle: Greenhouse Effect Greenhouse effect: Increase in environment temperature because of increase in atmospheric CO2 The reason for increased CO 2? Increased human activities (domestic, industry, etc) increased CO 2 emission Reducing CO 2 emission? Limiting emission not economical Social impacts Kyoto Protocol 1997 Increase global temperature increase in disease incidence 5

6 Relation of temperature increase & disease incidence Global warming Precipitation Ocean surface temperature Nutrient availability Phytoplankton Vibrio cholerae Zooplankton Cholera incidence Nitrogen Cycle Availability of nitrogen in the environment: in several oxidation states N 2 is the highest concentration of gas in the atmosphere Processes in N cycles: Nitrification Denitrification Nitrogen Fixation Ammonification Aerobe & anaerobe All above processes require microorganisms 6

7 N 2 Nitrogen Cycle N 2 O Nitrogen fixation NH 4 + ammonium oxidation NO 2 - denitrification NO Nitrite ammonifcation ammonium assimilation Ammonification R-NH 2 Assimilative NO - 3 reduction Nitrit oxidation NO 2 - Dissimilative NO 3 - reduction NO 3 - Utilization of N Cycle Research on N cycle is very active: Capability of bacteria for N fixation efforts to reduce use anorganic N fertilizer Isolation of anammox bacteria (anaerobic ammonia oxidation) transform N component of liquid waste into N 2 Development of inoculum for N fixation commercially Indonesia: Rhizoplus 7

8 Iron Cycle (Fe) organic C CO 2 Metabolism Anaerobe Reductive bacteria Fe(III) Fe(III) Plaque Metabolism Aerobe Oxidative bacteria Fe (II) Fe(II) solute Reduction Oxidation H 2 O root O 2 Sulphur Cycle redox reaction Microorganism: Beggiatoa, Thiothrix, Thiobacillus Gradient microorganism: lives on the interface of anaerobic environment, sediment, & oxygenated water. 8

9 Oksidasi sulfida H 2 S S 0 Aerob Desulfurisasi Respirasi sulfur S 0 Oksidasi fototrofik R-SH Reduksi sulfat disimilatif Reduksi sulfat asimilatif SO 4 2- Oksidasi fototrofik Anaerobe Bio corrosion: interaction between the S and Fe Cycle Occurrence of S cycle can cause corrosion of steel (Fe) pipes on soil that contains S The reaction: Fe 0 + H 2 O Fe(OH) 2 + H 2 4H 2 + SO 4 2- H 2 S + 2OH - + 2H 2 O H 2 S + Fe 2+ FeS + H 2 9

10 Acid Rain The Acid Rain phenomenon: H 2 SO 3 & H 2 SO 4 Acid rain can damage buildings & monuments made from marble & limestone How to prevent acid rain? Origins of Acid Rain 10