What do aquatic environments include?
- oceans, salt marshes, lakes, rivers, ponds, springs
What are microbial species composition affected by in aquatic environments?
- physical and chemical characteristics of environments
Define marine
- open ocean
- low primary productivity due to inorganic nutrients
- low heterotrophic activity
Where does primary productivity occur?
open areas due to prochlorophytes
What is a prochlorophyte? Give an example
- use light for energy, small oxygenic prokaryotes
- ex. trichodesmium
Why wouldn’t you find heterotrophs in marine environments
they like organic material
Where are barophiles found?
high pressure environments
What are the 3 environmental extremes in the deep sea?
- low temp
- high pressure
- low nutrients
Why is there low nutrients in deep sea?
missing light and organic matter from plants
What does psychrophilic mean?
Bacteria at depths below 4000 m
What is the relative increase of pressure of deep sea?
1atm every 10m
What depths can barotolerant microorganisms survive? What about barophilic?
- up to 3000m
- 4000-6000m
What is the difference between warm and hot?
- Warm : 6-23C + flow rate of 0.5-2cm/sec
- Hot: 270-380C + flow rate of 1-2m/sec
What is a hydrothermal vent
- habitat for hyperthermophilic bacteria in gradient where hot and cold water meet
- large amounts of inorganic material
Give an example of a hyperthermophile found in a hydrothermal vent
- methanopyrus
- chemolithic
What are biological communities in hydrothermal vent ecosystems dependent on? give an example
- Chemolithotrophic activity
- ex. Sulfur oxidizers (thiobacillus)
What is freshwater lacking?
Salt
What happens to O2 in freshwater
in surface layers (photosynthesis) but depleted with depth due to low water solubility
Why is O2 rapidly consumed in freshwater environments?
- feeds heterotrophic and organotrophic processes
How can lakes be reoxygenated?
- mixing
Define littoral zone - what will you find there?
where light hits the bottom
- organotrophs
Define limnetic zone - what will you find there?
- open water from shore
- phototrophs, pseudomonads
Define profundal zone - what will you find there?
deeper water under limnetic (purple and green sulfur bacteria)
Define benthic zone - what will you find there?
sediment at bottom
(methane bacteria)
