Lecture 21: Microbial Ecology and Symbiosis Flashcards
What is microbial ecology?
study of interactions of microbes with other organisms in its environment
What are populations?
Groups of microbes from same species
What are communities?
group of microbes from different species
How are microbes in nature different than microbes in lab?
- Mixed communities
- Conditions are not ideal
- Environment change over time
What are the two components of microbial diversity?
Richness - total number of species
Evenness - number of individuals per species
What is phylogenetic diversity?
evolutionary relatedness among species
What is rarefaction analysis?
A measure of species richness
WHat is the hyperdiversity paradox?
Unlimited diversity
-english channel sample contained 2/3 world’s microbes
What is the paradox of plankton and how was it resolved?
How limited number of resources can suppport seemingly limitless diversity of microbial species
Resolved by temporal variation, complex microenvironments, and metabolic specialization
WHat are microhabitats?
small environments on microbial scale
What are guilds and niches?
Guild - group of microbes that are metabolically similar and use same resources
Niches - habitats shared by microbial guild
What are the types of niches?
Prime - ideal habitat
Fundamental - full habitat range
How are microbial biofilms related to microhabitats?
used to group microbes that grow on surfaces or in water
What is the benefits of biofilms?
Defense, fixed location and close quarters
How are biofilms important to society?
Medicine (grow on implants) and industry (ship fouling)
What are the types of Symbioses and who benefits?
Mutualism = +/+ Commensalism = +/o Parasitism = +/-
What type of microbe rarely has symbionts?
archaea
What are the ecological impacts of symbiosis?
Supplemental nutrition and Increase host fitness
What are the different categories of symbioses?
Microbe-Microbe
Plant-Microbe
Animal-Microbe
What is an example of microbe-microbe symbiosis?
Lichens (fungus+cyanobacteria)
- mutualistic
- Fungus acts as anchor
- Cyanobacteria acts as food source
Consortia
- mutualistic
- reverse CAC
- motility from symbiosis = stratified water columns
What are some plant-microbe symbiosis?
Legumes
-mutualistic w/ Nitrogen fixing bacteria
Mycorrhizae
- mutualistic
- fungus gets more water for plant roots
What are some animal-microbe symbioses?
mammal gut microbiota
- cellulose digestion
- foregut + hindgut
- out of whack microbiota = obesity
-examples: termites, fungus ants
What are hydrothermal vents?
Discovered in 1977
- Tubeworms discovered w/ no anus or mouth
- Contain sulfur oxidizing symbionts=fix carbon
How biodiverse are coral reefs?
25% of marine species live there but make up <1% of the area
