Nutrient Movement

Question 1

What is nutrient movement and metabolic diversity

Answer 1

study of the interaction of microorganisms with each other and their physical environment

Question 2

What is an ecosystem and what does it consist of?

Answer 2

• a community of organisms and their natural environment
• consists of physical things (organisms) and the abiotic environment

Question 3

Define abiotic

Answer 3

physio-chemical parameters of environment

Question 4

Does structure always translate to function? Explain.

Answer 4

• no, some clusters of genes/triggers can be missing
• sometimes they aren’t regularly expressed (some factors may give competitive advantage + also help with antibiotic resistance

Question 5

Define population

Answer 5

a single colony arisen from an individual cell

Question 6

Define guild

Answer 6

metabolically related group of organisms (can survive in same environment)

Question 7

What does it mean when organisms can exist in the same environment?

Answer 7

complementary metabolism

Question 8

Define community

Answer 8

total collection of all organisms in population (multiple guilds)

Question 9

What is important to consider when looking at ecosystems?

Answer 9

• energy flow
• nutrient cycling

Question 10

What is an anoxic anaerobe?

Answer 10

does not need oxygen at all

Question 11

What are the 2 main objectives of microbial ecology?

Answer 11

• biodiversity
• measure of activities

Question 12

What is the importance of biodiversity?

Answer 12

• nutrients are cycled - if not they are hung up and system would not survive

Question 13

What is the importance of measuring activity?

Answer 13

• they work in parallel with functional profile
• monitor effects on ecosystem

Question 14

What is required for organisms to reproduce?

Answer 14

• nutrients and appropriate environmental conditions (abiotic)

Question 15

What are some examples of abiotic conditions?

Answer 15

• temp
• pH
• Water activity (aw)
• Oxygen
• Nutrients

Question 16

What is Aw?

Answer 16

water activity - has least amount of room for change

Question 17

What is a niche and what does it include?

Answer 17

• the functional role of an organism, where it is functionally active
• location, nutrients used

Question 18

What is a microenvironment?

Answer 18

• habitat and conditions where microorganism lives
• can be highly changeable (heterogeneous) because they are small
• permits growth of physiologically distinct groups

Question 19

What is the difference between niche and microenvironment?

Answer 19

• a niche is where the microorganism is FUNCTIONAL
• a microenvironment is where the microorganism is FOUND

Question 20

Explain what growth of physiologically distinct groups means

Answer 20

• they can be near one another
• ex. e.coli is facultative anaerobe and will layer to grab O2 as it cycles through –> protects anoxic anaerobes

Question 21

What does facultative anaerobe mean and what is an example?

Answer 21

• capable of switching from aerobic to anoxic if needed
• ex. E. Coli

Question 22

What are causes of slow growth rates in nature?

Answer 22

• low nutrient supply or non-uniform distribution
• competition for resources

Question 23

Why is exponential growth slower in nature than in lab?

Answer 23

• conditions are harder to find in nature
• lab is specialized and can add nutrients/oxygen when needed but it is not readily available in nature
• competition

Question 24

Where is microbial growth optimal in natural environment (location)? Why?

Answer 24

When attached to a surface because they have higher levels of absorbed nutrients and more moisture

Question 25

What is a good analogy to explain why microbes find it optimal to be attached to a surface?

Answer 25

- bouncing around a classroom while trying to catch a ball (nutrients)

Question 26

What attaches to surfaces first?

Answer 26

Chemical particles due to charge and surface tension

Question 27

What are pioneer organisms?

Answer 27

first set of organisms to scavenge a new surface

Question 28

Define biofilm

Answer 28

- community/colony embedded in an organic polymer matrix attached to a surface

Question 29

What is an organic polymer matrix?

Answer 29

extracellular polymer substance/exopolysaccharide

Question 30

Define microbial mat, give an example

Answer 30

- complex macroscopic layered microbial communities (can see with naked eye) - edge of a beach

Question 31

List areas that biofilms cause significant negative impact

Answer 31

- artificial implants - dental disease - reduced water flow in pipelines - portable water quality - degradation and corrosion increase

Question 32

list areas that biofilms are useful

Answer 32

- leaching of low grade ores (need it to extract) - food fermentation (want it in GI tract) - filtration (clean it)

Question 33

What is a low grade ore?

Answer 33

ore with low concentration of metals

Question 34

Define competition

Answer 34

when multiple organisms acquire same resource (nutrients/space)

Question 35

What do microbial interactions depend on?

Answer 35

- rates of nutrient uptake - metabolic and growth rates (some are different and can co-exist)

Question 36

Define the competitive exclusion principle

Answer 36

- if you compete long enough, one group is bound to lose

Question 37

Define antagonism

Answer 37

- one microorganism inhibits growth/metabolism of another - excretion of inhibitor or toxic metabolite

Question 38

Define syntrophy

Answer 38

- 2 or more organisms WORK TOGETHER to carry out transformation they cannot do individually

Question 39

What is the difference between antagonism and syntropy in regard to "running a race"

Answer 39

- antagonism = sticking out foot to trip - syntropy = simply racing

Question 40

Why is syntropy important?

Answer 40

- nutrients do not cycle properly without multiple organisms (each do a different transformation)

Question 41

What is partial nitrification

Answer 41

- chemical transformation faster than biological, may deprive particular group - competition - biological transformation keeps things moving