Microbial Communities and Interactions Flashcards
Fundamental Niche
-the theoretical range of environments where a given microbe COULD live
realized niche
-the range of environments where the microbe ACTUALLY lives in the real world
what determines the difference between fundamental and realized niches
-interactions with other microbes
co-evolution
-evolution guided by nature of relationships between organismss
symbiosis
-a close long term interaction between different organisms
-organisms can benefits, be harmed or be unaffected
-often involves coevolution
mutualism
-both organisms benefit from symbiotic relationships
commensalism
-one orgamism benefits, other unaffected
parasitism
-one organims benefits othe ris harmed
oblogate symbionts
-some organisms strictly require symbiotic relationships for growth and survival
facultative symbionts
-do not require symbiotic relationships for growth and surival
lichens
-microbial communities comprised of a fungus and a alga, or a fungas and a cyanobacterium
-minor species also present
-grow slowly and have very long lifespans
how do the fungi in a lichen benefit in the symbiotic relationship
-photosynthetic partner produces organic compounds for fungus (food_
how do the algae/cyanobacteria benefit rom the lichen symbiotic relationship
-fungus provides anchor and controlled environment for growth
-structure helps retain water for algae
-fungus sometimes releases lichen acids to free up inordganic metabolites for algae and cyanobacteria
fungus obligate symbionts
-specific fungal species often obligate symbionts - partner can sometimes live freely but symbiotic relationships drastically expands ecological range of both partners
why do some people consider lichens controlled parasitism
-fungi drastically slow partners growth consume a great deal of nutrients
microbial consortium
-two or more microbes living in a symbiotic relationship
freshwater lake common found consortium is comprised of
-numerous non-motile photosynthetic bacteria = moves consortium to location optimal for photosynthesis
-central motile non-photosynthetic bacterium = provide nutrients to motile (chemoorganotrophic bacterium
chlorochromatium aggregatum
-green sulfur bacteria - phototrop
-beta proteobacterium - motile
beta proteobacterium at center of chlorochromatium aggregatum
-obligate symbiont and cannot live on its own
-has suffered signifcant gene loss– metabolism dependent on consortium and enriched for chemotaxis genes
-green sulfure bacteria of chlorochroatium aggregatum
-can be culutred but not observed free living in nature
-not prosperous without ability to localize to optimal niches in lake
is chromatium aggregatum co evolution
-yes
does the species in c.aggregatum make direct contact
-yes through protrusions
composition of soil
-bacteria dominate but archaea also important
-eukaryotes lower abundance
-different micro-environments occur within soil
-complex interactions are dynamic
-lots of syntrophy (cross-feeding)
-community level metabolic processes
-direct cmbat through antimicrobial mechanisms
community level metabolic processes
-metabolic proccesses that require many distinct organisms to complete
