Environmental Microbiomes

Question 1

Define microbiome and microbiota

Answer 1

A microbiome is the combined genetic material of all microorganisms in an environment
Microbiota is all the microorganisms found in a particular environment

Question 2

What are the 2 groups of diazotrophs?

Answer 2

Endosymbionts - live in root nodules
Plant growth promoting rhizobacteria - free living

Question 3

What are Mycorrhizae fungi?

Answer 3

Mycorrhizae increases access to nutrients and water
Locked up nutrients may be solubilised by mycorrhizae thereby become accessible by the root

Question 4

Give an example of nitrogen fixing bacteria

Answer 4

Nitrogen fixing bacteria - Azotobacter, Rhizobium convert N2 to NH3/NH4

Question 5

Give an example of nitrifying bacteria

Answer 5

Nitrifying bacteria - Nitrosomas convert NH3 to NH4 to NO2, Nitrobacter convert NO2 to NO3

Question 6

Give an example of denitrifying bacteria

Answer 6

Denitrifying bacteria - Pseudomonas convert NO3 to N2

Question 7

What is the function of lichens?

Answer 7

Lichens deteriorate rock by secreting acids, nitrogen fixation by cyanobacteria

Question 8

What is the function of soil organic matter?

Answer 8

Retains nutrients
Holds more water for plant use
Maintains soil structure
Mineral soils contain < 20% organic carbon, organic soils > 20% organic carbon