BIOL1007 Lecture Notes - Lecture 17: Biogeochemistry, Species Problem, Carbon Cycle
Vast majority of all biodiversity (taxonomic, metabolic and niche diversity) is microbes
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Most microbes CANNOT be isolated or cultured
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Appreciate that the majority of life’s diversity is microbes
Agar plates
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Microscopy (more detail)
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DNA sequences (even more detail)
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But still can't see all species - problem in microbiology
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Microbiology
Where biology, chem and geology meet
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i.e. biological processes that impact on chem at a GLOBAL SCALE
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Most of these reactions are done by MICROBES
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e.g. Carbon cycle
Biogeochemistry
Everything is connected
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Everything must go somewhere
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Nature knows best
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Laws of ecology
Define an autotroph and a heterotroph, and give
microbial examples of each of these
Autotroph = Self-feeder - uses CO2 as carbon source
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Heterotroph = "other-feeder", needs to eat other organisms or other organic carbon sources
(which also supply energy)
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Describe the role of microbes in the carbon cycle
Explain the impact of microbes on global climate change ‐
as sources and sinks (removal) of CO2 and CH4
Autotrophs
Use SUNLIGHT as energy source (photoautotrophs) OR chem energy sources
(chemoautotrophs)
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Bring CO2 back into circulation as organic carbon forms
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Autotrophs convert inorganic C to organic C, act as "SINKS" for CO2 -> act to limit
climat change
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Autotroph = Self-feeder - uses CO2 as carbon source
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Algae perform about 50% of global photosynthesis
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Remember! Microbial processes (e.g. algal blooms) have impacts at global scales
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Algae (free-living)
Consume CO2 and H2
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Produce methane CH4
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Type of chemoautotrophs: CO2 is carbon source, H2 is energy source
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Net reaction is BAD
Impact on climate change = remove CO2 (good) BUT act as sources of CH4 (BAD!)
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Methanogens
L17 - Planetary Health: Microbes & Ecosystems
Tuesday, 3 October 2017
9:10 PM
Mod 3 Global Health Page 1
Document Summary
Appreciate that the majority of life"s diversity is microbes. Vast majority of all biodiversity (taxonomic, metabolic and niche diversity) is microbes. But still can"t see all species - problem in microbiology. Where biology, chem and geology meet i. e. biological processes that impact on chem at a global scale. Most of these reactions are done by microbes e. g. carbon cycle. Define an autotroph and a heterotroph, and give microbial examples of each of these. Describe the role of microbes in the carbon cycle. Explain the impact of microbes on global climate change as sources and sinks (removal) of co2 and ch4. Autotroph = self-feeder - uses co2 as carbon source. Use sunlight as energy source (photoautotrophs) or chem energy sources (chemoautotrophs) Autotrophs convert inorganic c to organic c, act as sinks for co2 -> act to limit climat change. Bring co2 back into circulation as organic carbon forms. Microbial processes (e. g. algal blooms) have impacts at global scales.