Microbial Interaction Flashcards
Chapter 3
What are biological interactions?
Effects that organisms in a community have on one another.
Why are microbial interactions important?
They are critical for biological community function and global biogeochemistry.
How are microbial interactions classified?
Based on whether both populations benefit, one benefits, or both are negatively affected.
Name the types of positive microbial interactions.
Mutualism, syntrophism (synergism), proto-cooperation, commensalism.
Name the types of negative microbial interactions.
Amensalism (antagonism), parasitism, predation, competition.
Define mutualism.
A relationship where both organisms benefit and depend on each other metabolically.
Provide two examples of mutualism.
Lichens (fungi and algae)
Nitrogen-fixing bacteria in legume root nodules.
What is syntrophism?
Interaction where the growth of one organism is enhanced by substrates from another
Example of syntrophism?
Lactobacillus arobinosus provides folic acid for Enterococcus faecalis, which produces phenylalanine for Lactobacillus.
Define commensalism.
A relationship where one organism benefits, and the other is neither harmed nor benefited.
Provide an example of commensalism.
Non-pathogenic E. coli in the human gut creates an environment for obligate anaerobes like Bacteroides.
Define predation.
Interaction where one organism (predator) consumes another (prey).
Provide an example of predation.
Bdellovibrio preying on gram-negative bacteria.
What is competition in microbial interaction?
A negative relationship where both populations are adversely affected due to shared resources.
Example of microbial competition?
Paramecium aurelia outcompeting Paramecium caudatum for bacterial food.
