16 - The Changing Environment Flashcards
Natural events that cause environmental change
- Seasonal changes
- Natural disasters
- Natural climate changes due to orbit changes, solar variations
- Changes in species relationships
Man made events that cause environmental change
- Land use/farming
- Deforestation
- Urbanisation
- Increasing population
- Pollution
- Climate change
What are microbes critical for
- Colonising and promoting all animal life on planet
- Photosynthesis (5 groups contribute to carbon fixation)
- Recycle nutrients
- Enrich soils for plant growth
Volcanic activity
- Dramatic effects on localised environment
- Volcanic gas and ash into atmosphere, react with atmospheric gases
- Lava flows damaging surrounding area
- Tsunamis
Volcanic gas and ash reacting with atmospheric gases
- Conversion of sulfur dioxide to sulphuric acid
- Ozone destruction
- Increase in CO2
Natural cycle of climate change
- The earth goes through naturally induced cooling and warming events
- Occur of very long periods of time
Microbes and climate change
- Control biogeochemical cycling of all elements essential for life
- Generate and consume gases that effect climate
Drought
- Prolonged drought leads to desertification and loss of microbial diversity and functionality
- 20% of the earths soil has been degraded by drought
- Has significant impact on
ability to grow crops
Flooding
- Soils saturated in water have reduced microbial diversity
- Increase in methanotrophs, decrease in aerobic activity
- Leads to chemical contamination of soils and environment
Effect of pollution on microbial communities
- Atmospheric pollution contains heavy metals that convert to more toxic compounds
- Farm land river run off increases nitrates in seas and river ecosystems
- Accumulation of inorganic waste in soils and in the ocean
- Fecal pollution from humans and farming effects diversity
and abundance of microbes in aquatic systems
Primary pollutants
- Carbon monoxide
- Sulphur dioxide
- NItrogen dioxide
Secondary pollutants
- Nitric acid
- Sulphuric acid
- Hydrogen peroxide
Many infectious diseases are impacted by changing environment
- Land clearing can bring new diseases into proximity to new populations
- Air pollution can increase impact of viral respiratory infections
- Chemical pollution can make humans more susceptible to
infections - Climate change has increased range and indeicence of vector borne infections
Airborne pollution and respiratory infections
- Airborne pollution has been shown to effect both the SARS and SARS-cov-2 disease symptoms
- Exposure to sulphur dioxide increases risk of influenza infections
How do inhaled pollutants reduce host immunity
- Enhanced viral activation and entry
- Impaired TLR activation
- Impaired intracellular pathway activation
- Impaired antiviral immune signalling
- IMpaired immune cell function
Control of malaria
- Draining of swamps
- Long been used to reduce malaria transmission in endemic regions
Why look at microbes to measure change
- Microbes respond to small changes to their environment
- Can be used as a sensitive measure of environmental change
- Exist in every environment in great diversity
- Evolve fast - faster reflection of change
- Easily studied in the lab
- No ethics
Metataxanomics
- Using an amplicon to classify microbes
- Lacks information
Metagenomics (WGS sequencing)
- Sequences genomic material of complete biome
- Huge data
Metatranscriptomics
Sequencing of microbial transcriptome
rtPCR sequencing
Required for RNA viral diversity
Bioremediation
- Process that uses microbes to repair environmental damage by using harmful contaminants as source of energy
- Help prevent further degradation
Bioaugementation
Addition of bacterial cultures to contaminated mediums
Biofilters
Use of microbial columns to treat air emissions of volatile compounds
Bioventing
Method of treating contaminated soils by drawing oxygen through soil to stimulate microbial growth
Biostimulation
Stimulation of indigenous microbial populations in soils or ground water
Bioreactor
Treating waste in reactors to protect environment
Land farming
Solid phase treatment for contaminated soils
Bioslurping
Vacuum enhanced dewatering technologies to remediate hydrocarbon contaminated sites
