Unit 16 - Microbial Ecosystems

Define ecosystem

Collection of plants, animals, and microbial communities with abiotic surroundings

Define population

Group of microbes descended from a single cell

Define community

Multiple types of populations

What are the two measurements of microbial diversity?

• Species Richness

• Species Abundance

Define species richness

Number of unique species

Define species abundance

Proportion of each species

Microbial diversity is measured by what?

16S rRNA

Define microenvironment

Space in which microbe directly interacts

Define fundamental niche

The various environmental conditions that promote growth

What defines a niche (4)

• Nutrients

• Energy

• Temperature

• O2 level

Define the O Horizon

Undecomposed plant material

Define the A horizon

plant roots extend, microbial activity is high

Define B horizon

Minerals are concentrated and microbial activity decreases

Define C Horizon

Forms the base, supports large plants like trees

What is the rhizosphere

The most microbially active soil, associated with plant roots

Oxygenic phototrophs are what in freshwater environments?

Primary producers

What does BOD stand for?

Biochemical Oxygen Demand

Define the Biochemical oxygen demand

Water quality assessment

How does BOD work?

Water sample stored in dark, 20^oC, 5days. Afterwards the O2 is measured

What does low O2 mean in BOD?

Higher BOD, more potential for bacterial growth

What is a pelagic zone?

An open ocean marine environment

What is an oligotrophic environment?

Low nutrient environment, Pelagic zone

Deep-sea hydrothermal vents provide what that fuel who?

Electron-rich molecules // chemolithotrophs