L 21. Planetary health: Microbes & Ecosystems

Question 1

L.O.

Answer 1

• Appreciate diversity of microbes
• Appreciate types of microbes – bacteria, archea, protists, fungi
• Understand different roles of microbes in the environment
• Understand autotrophs – phototrophs and chemotrophs (methanogens)
• Heterotrophs
• Decomposers
• Predators
• Understand using microbes to clean up pollutants
• Understand symbiotic relationships
• Coral symbiosis
• Lichen symbiosis

Question 2

Scope of biodiversity

Answer 2

• Microbes make up vast majority

Biodiversity = taxonomic, metabolic, niche diversity

Most microbes cannot be isolated or cultured

Question 3

Biogeochemistry

Answer 3

Bio, chem, geology
- most reactions are by microbes
- Carbon cycle

Question 4

4 laws of ecology

Answer 4

1. Everything is connected
2. Everything must go somewhere
3. Nature knows best
4. no such thing as a ‘free lunch’

Question 5

Autotrophs in the carbon cycle - Algae

Answer 5

Self feeding “sinks” for CO2, taking out of atmosphere

Photoautotrophs - light energy
Chemoautotrophs - chemical energy

Converts inorganic CO2 into organic carbon

Question 6

Autotrophs in the carbon cycle - Methanogens

Answer 6

Consume CO2 and H2O producing CH4
- Methanogens are chemoautotrophs
- Methanogens are sinks of CO2 but sources of CH4
- Methanogens are archaea and anaerobic

Question 7

Heterotrophs in the carbon cycle - Methanotrophs

Answer 7

• Consume CH4 and produce CO2
• Heterotrophs as CH4 is organic carbon energy
• Sink for CH4, source of CO2 (Net overall is good)
• Bacteria
• Break down Hydrocarbons by enzymes

Question 8

Heterotrophs in the carbon cycle - Decomposers

Answer 8

Source of CO2 (increasing climate change)
- Recycle dead cells back into CO2
- Major = Fungi

Question 9

Heterotrophs in the carbon cycle - Predators

Answer 9

• Protists are often predators of microbes
• Some protists are ddetrivors/ scavangers and some are photosynthetic

Question 10

Heterotrophs in the carbon cycle - Pollutant Degraders

Answer 10

• Hydro-carbon degrading bacteria are important for ‘Bioremediation’ (clean up of pollution by microbes. eg. methanotrophs)
• Hydro-carbon degrading bacteria are heterotrophs that eat ancient fossilized organic matter
• Similar to decomposers but have enzymes that can attach hydro-carbons

Question 11

Autotroph and Heterotroph interactions Coral example

Answer 11

Coral Symbiosis
- Coral = Primitive heterotrophic animals that depend on symbiotic microscopic algae to supply them food.
- Algae = Photoautotroph

The carbon is cycled between organic and inorganic carbon allowing both parties to benefit

Question 12

Autotroph and Heterotroph interactions Lichen example

Answer 12

Lichens = Primary producers in some terrestrial ecosystems
- Photosynthetic but are NOT plants
- Symbiosis of 2 microbes

Lichen = Heterotrophic Fungus + Autotrophic Algae

Question 13

Autotrophs summary

Answer 13

• Algae (free living) = Phototrophic
• Algae (coral symbiosis) = Phototrophic
• Methanogens = Chemotrophic
• Algae (lichen symbiosis) = Phototrophic

Question 14

Summary of Heterotrophs

Answer 14

• Decomposers (detrivors)
• Methanotrophs
• Coral (host of symbiosis)
• Predators (protazoa)
• Hydro-carbons = degraders
• Lichen (Host of symbiosis)