Microbial Communities and Interactions

Question 1

Fundamental Niche

Answer 1

-the theoretical range of environments where a given microbe COULD live

Question 2

realized niche

Answer 2

-the range of environments where the microbe ACTUALLY lives in the real world

Question 3

what determines the difference between fundamental and realized niches

Answer 3

-interactions with other microbes

Question 4

co-evolution

Answer 4

-evolution guided by nature of relationships between organismss

Question 5

symbiosis

Answer 5

-a close long term interaction between different organisms
-organisms can benefits, be harmed or be unaffected
-often involves coevolution

Question 6

mutualism

Answer 6

-both organisms benefit from symbiotic relationships

Question 7

commensalism

Answer 7

-one orgamism benefits, other unaffected

Question 8

parasitism

Answer 8

-one organims benefits othe ris harmed

Question 9

oblogate symbionts

Answer 9

-some organisms strictly require symbiotic relationships for growth and survival

Question 10

facultative symbionts

Answer 10

-do not require symbiotic relationships for growth and surival

Question 11

lichens

Answer 11

-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

Question 12

how do the fungi in a lichen benefit in the symbiotic relationship

Answer 12

-photosynthetic partner produces organic compounds for fungus (food_

Question 13

how do the algae/cyanobacteria benefit rom the lichen symbiotic relationship

Answer 13

-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

Question 14

fungus obligate symbionts

Answer 14

-specific fungal species often obligate symbionts - partner can sometimes live freely but symbiotic relationships drastically expands ecological range of both partners

Question 15

why do some people consider lichens controlled parasitism

Answer 15

-fungi drastically slow partners growth consume a great deal of nutrients

Question 16

microbial consortium

Answer 16

-two or more microbes living in a symbiotic relationship

Question 17

freshwater lake common found consortium is comprised of

Answer 17

-numerous non-motile photosynthetic bacteria = moves consortium to location optimal for photosynthesis
-central motile non-photosynthetic bacterium = provide nutrients to motile (chemoorganotrophic bacterium

Question 18

chlorochromatium aggregatum

Answer 18

-green sulfur bacteria - phototrop
-beta proteobacterium - motile

Question 19

beta proteobacterium at center of chlorochromatium aggregatum

Answer 19

-obligate symbiont and cannot live on its own
-has suffered signifcant gene loss– metabolism dependent on consortium and enriched for chemotaxis genes

Question 20

-green sulfure bacteria of chlorochroatium aggregatum

Answer 20

-can be culutred but not observed free living in nature
-not prosperous without ability to localize to optimal niches in lake

Question 21

is chromatium aggregatum co evolution

Answer 21

-yes

Question 22

does the species in c.aggregatum make direct contact

Answer 22

-yes through protrusions

Question 23

composition of soil

Answer 23

-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

Question 24

community level metabolic processes

Answer 24

-metabolic proccesses that require many distinct organisms to complete