microbial ecology

Question 1

ecosystem

Answer 1

community of organisms and their natural environment

Question 2

population

Answer 2

group of organisms in the same species in the same space at the same time

Question 3

guild

Answer 3

metabolically similar organisms that exploit the environment in the same way

Question 4

organisms that consume chemicals as energy source

Answer 4

chemotrophs

Question 5

organisms that consume light as energy source

Answer 5

autotrophs

Question 6

organisms that use organic sources for electron donation (and name an example of an organic source)

Answer 6

organotroph; glucose

Question 7

organisms that use inorganic sources for electron donation (and name an example of an inorganic source)

Answer 7

lithotroph; NH3, S0, H2

Question 8

organisms that use organic sources for carbon source (and name an example of an organic source)

Answer 8

heterotroph; glucose

Question 9

organisms that use inorganic sources for carbon source (and name an example of an inorganic source)

Answer 9

CO2

Question 10

electron acceptor examples (anaerobic or aerobic)

Answer 10

O2 (aerobic), NO3, SO4, FeIII

Question 11

What type of respiration to e. coli use? what do they optimally use?

Answer 11

aerobic = optimal; can also use fermentation

Question 12

What is the difference in respiration between chemoorganotrophs and chemolithotrophs?

Answer 12

organic compound allows for glycolysis, TCA cycle, and ETC, while inorganic compounds allows only for ETC

Question 13

what form of metabolism would a microbe exhibit if it’s helpful for C,N,S cycling

Answer 13

chemolithoautotrophy (they are NH3-oxidizers, NO2-oxidizers)

Question 14

what form of metabolism would an organism exhibit if it’s a primary producer?

Answer 14

photolithoautotrophy

Question 15

what are the 4 main groupings of phototrophic bacteria? what are their oxygen requirements??

Answer 15

purple sulfur/non sulfur, green sulfur/nonsulfur, heliobacteria - anoxygenic
cyanobacteria - oxygenic

Question 16

main areas of study in microbio

Answer 16

primary production, decomposition, biogeochemical cycling

Question 17

what are the necessities of growth

Answer 17

resources, and physiochemical conditions

Question 18

types of extremophiles

Answer 18

psychrophiles, thermophiles, hyperthermophiles,

Question 19

niche

Answer 19

functional role of an organism within an ecosystem; combined definition of physical habitat, functional role, and interactions of microorganisms occurring at a given location

Question 20

microenvironment

Answer 20

where a microorganism lives, and metabolizes within its habitat - a v small region of space, fractions of millimeters in diamater

Question 21

what is the difference between microbes in lab vs life?

Answer 21

life:

1. entry of nutrients is intermittent, so there is a feast or fast existence. this means that there is plenty of accumulations and reserves, and when there is nutrients, there are v high levels of growth, but extended periods of growth are v rare in nature
2. distribution of resources in nature is often non-uniform
3. competition for resources is likely

Question 22

biolfilm

Answer 22

a community of organisms organized in a community adhered to a surface, embedded in a matrix of organic polymer (EPS); can organise EPS so there are water channels through

Question 23

advantages to biofilm mode

Answer 23

protection for toxins, predators, immune system cells; ability to remain in favourable niche; cooperative interactions possible; nutrient trapping

Question 24

disadvantages to biofilm mode

Answer 24

highly competitive, localised biomass can be preyed upon, infected by viruses

Question 25

human-scale problems resulting from biofilm

Answer 25

pipe clogging; corrosion of pipes; high microbial amounts in potable water distribution system; increased drag on ship hull; periodontal issues; surgical issues (infection)

Question 26

microbial mat defintion + where are they found + 1 example

Answer 26

specialised microbial communities composed mainly of photosynthetic and chemolithotrophic bactera; extremely thick; found in hot springs and other extreme environments; cyanobacterial mats are a complete ecosystem

Question 27

different interactions between microbial populations

Answer 27

negative-effect interactions, positive-effect interactions, symbiosis

Question 28

different types of negative-effect interactions

Answer 28

antagonistic and competitive
antagonist - specific inhibitor may impede growth/metabolism of others (antibiotic release or lactic acid production - lowered pH would affect a microbes who like a more basic env)
competitive - outcome depends on innate capabilities of nutrient uptakes, metabolic rates

Question 29

different types of positive-effect interactions

Answer 29

cooperative interactions - interacting microbes must share same/nearby environment; two types - syntrophy and complementary metabolic interactions
symbiosis: intimate relationship between 2 or more organisms that share a particular ecosystem

Question 30

mutualism

Answer 30

type of symbiosis where both species benefit

Question 31

parasitism

Answer 31

type of symbiosis where only one species benefits, other is harmed

Question 32

syntrophy

Answer 32

microorganisms carry out interactions neither can do on their own
types op positive-effect interaction between microbes

Question 33

complementary metabolic interactions

Answer 33

microorganisms carry out interactions using the products or byproducts of another organism
eg nitrification
type of positive-effect interaction between microbes

Question 34

symbiosis in e.coli & ur gut

Answer 34

can be damaging or beneficial to the host

mutualism: you provide them w a protected environment n nutrients, they give you vitamin K
commensal: you can get vitamin K elsewhere
parasitic: under the right conditions they can cause disease if they gain access to body tissues

Question 35

commensal

Answer 35

type of symbiosis where one species benefits, the other is unaffected