Download Siklus Biogeo_2008

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)
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Biogeochemical Cycle
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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
N2
Microorg (100)
Microorg (53)
Humans (41)
O2
Microalgae
Plants
Microorg, animals
negligible
CO2
Microorg(86), Animals,
Humans
Microalgae
Plants
+0,4%
CH4
Microorg(26), Animals
(17), Humans (57)
Microorg,
chemicals
+1%
N2O
Microorg (50), Humans
(50)
Microorg (?),
Chemicals (?)
+0,3%
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Carbon Cycle (C) & Oxygen (O)
The C Cycle cannot be separated from the O cycle:
– CO2 fixation
– Organic substance oxidation CO2
Global transfer of C occurs in the form of CO2 (most
active reservoir)
The C cycle involves activity of micro- and macroorganisms
Main role of microorganisms: DECOMPOSER organic
substances
Global C Cycle
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Main Stages of the C Cycle
Photosynthesis:
– Organic C production by autotrophs
Degradation /Decomposition:
– The utilization of organic C organik by
microorganisms, forming:
• CO2
• CH4
– 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 CO2?
– Increased human activities (domestic, industry, etc) increased CO2 emission
Reducing CO2 emission?
– Limiting emission not economical
– Social impacts Kyoto Protocol 1997
Increase global temperature increase in disease
incidence
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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
N2 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
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Nitrogen Cycle
N2
Nitrogen
fixation
N2O
ammonium oxidation
denitrification
NH4+
NO2 -
Nitrit oxidation
NO
Nitrite
ammonifcation
ammonium assimilation
Ammonification
R-NH2
Assimilative NO3 - reduction
NO2 -
Dissimilative NO3 - reduction
NO3 -
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 N2
Development of inoculum for N fixation commercially
Indonesia: “Rhizoplus”
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Iron Cycle (Fe)
organic C
CO2
Metabolism
Anaerobe
Reductive bacteria Fe(III)
Reduction
Fe(III)
Plaque
Fe(II)
solute
Metabolism
Aerobe
Oxidative bacteria Fe (II)
H2O
Oxidation
root
O2
Sulphur Cycle
• redox reaction
• Microorganism: Beggiatoa,
Thiothrix, Thiobacillus
• Gradient microorganism:
• lives on the interface of
anaerobic environment,
sediment, & oxygenated
water.
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Aerob
Oksidasi sulfida
H2S
S0
Respirasi sulfur
Oksidasi fototrofik
Desulfurisasi
S0
R-SH
Reduksi sulfat
asimilatif
Reduksi sulfat
disimilatif
SO4 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:
– Fe0 + H2O Fe(OH)2 + H2
– 4H2 + SO4 2- H2S + 2OH- + 2H2O
– H2S + Fe 2+ FeS + H2
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Acid Rain
The Acid Rain phenomenon: H2SO3 & H2SO4
Acid rain can damage buildings & monuments
made from marble & limestone
How to prevent acid rain?
Origins of Acid Rain
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