Environmental Microbiology

Front 1

What is environmental microbiology?

Back 1

-the study of microorganisms as they occur in their natural habitats

Front 2

What is microbial ecology?

Back 2

-the study of interrelationships among microorganisms and their environment

Front 3

What are two aspects to consider in environmental microbiology?

Back 3

1) levels of microbial associations in the environment
2) role of adaptation in microbial survival

Front 4

How many bacteria do we know well? Why is this?

Back 4

-17 phyla
-they're the only ones we could grow in culture

Front 5

Whatis most interesting about the Archaea group?

Back 5

-most are extremophiles

Front 6

What are thre ways biodiversity is held in balance.

Back 6

1) competition
2) antagonism
3) cooperation

Front 7

What is competition in biodiversity?

Back 7

-best adapted microorganisms have adcantageous traits

Front 8

What is antagonism in biodiversity?

Back 8

-microbe makes product that actively inhibits the growth of another

Front 9

What is cooperation in biodiversity?

Back 9

-microbe's metabolic activities make the environment more favorable for toher microbes which can lead to biofilms

Front 10

What are biofilms?

Back 10

-microbial communities
-probably the most predominant form of bacteria
-have a huge impact on infections in humans

Front 11

List the most common inhabitants of soil from greatest to least.

Back 11

-bacteria
-fungi
-algae

Front 12

What are five things that influence the composition of microbes in the soil?

Back 12

-moisture content
-oxygen
-pH
-temperature
-nutrient availability

Front 13

What are most soil organisms (because of temperature)?

Back 13

-mesophiles

Front 14

What is aquatic microbiology?

Back 14

-the study of microoganisms living in freshwater and marine environments

Front 15

What are some types of aquatic environments and what dictates this?

Back 15

Salt content breaks groups into:
-freshwater systems
-marine systems
-specialized aquatic systems

Front 16

What salt content is required to make water a marine system?

Back 16

-3.5%

Front 17

What are three ways that can cause water pollution?

Back 17

-physically (oil and organisms)
-chemically
-biologically (E. coli)

Front 18

What do chemoorganotrophs use for ATP?
Chemolithotrophs (typically live in soil)?

Back 18

-glycolysis and Krebs cycle
-use inorganics for ATP

Front 19

What are biogeochemical cycles?

Back 19

-processes by which organisms cycle nutrients
-elements often converted between oxidized and reduced forms
-organisms convert inorganics into biomass

Front 20

What are the three processes that biogeochemical cycling entails (also the basis of all cycles)?

Back 20

1) Production
2) Consumption
3) Decomposition

Front 21

What happens in biogeochemical cycling during production?

Back 21

-conversion of inorganic compounds into the organic compounds of biomass

Front 22

What happens in biogeochemical cycling during consumption?

Back 22

-organisms eat other organisms, in the process converting organic molecules into other organic molecules

Front 23

What happens in biogeochemical cycling during decomposition?

Back 23

-conversion of organic compounds in dead organisms into inorganic compounds

Front 24

What are some other important biogeochemical cycles?

Back 24

-carbon
-nitrogen
-sulfur
-phosphorus
-some trace minerals

Front 25

What is the main point to take away from the simplified carbon cycle?

Back 25

-too much combustion is occuring; cycle being pulled drastically to the right

Front 26

Does noncyclic phosphorylation use both PSI and II?

Back 26

Yes. PS I only is for cyclic since it returns to the beginning

Front 27

What are prokaryotic phototrophs?

Back 27

-primary producers of organic molecules

Front 28

What are the two types of prokaryotic phototrophs?

Back 28

1) oxygenic
2) anoxygenic

Front 29

What happens in oxygenic cycles?

Back 29

-uses H2O as reducing power in electron transport chain and noncyclic photophosphorylation

Front 30

What happens in anoxygenic cycles?

Back 30

-uses inorganic molecules as reducing power in electron transport chain and cyclic photophosphorylation (usually found in anoxic environments near source of H2S

Front 31

What are some bacterial fermentators?

Back 31

-Clostridium
-Lactobacullus
-Streptococcus
-Ruminococcus
-Peptostreptoccus
-Bacteroides

Front 32

What is chemolithotrophy?

Back 32

-obtaining energy from teh oxidation of inorganic molecules; ATP synthesis is the same as cheoorganotrophs but electron donors are different

Front 33

Why are inorganic electron donors so effective?

Back 33

-they have very high delta G values and they're abundant in environment (ex; -387 for sulfur)

Front 34

Who is capable of fixing nitrogen?

Back 34

-only prokaryotes

Front 35

What two types of nitrogen fixation can occur?

Back 35

-free living
-symbiotic
*very expensive! uses nitrogenase

Front 36

How does the nitrogen cycle work?

Back 36

-atmospheric nitrogen is fixated into ammonia.
-ammonia and water form ammonium ion
-ammonium ion goes to nitrite (toxic) then nitrate
*main part is immediate converstion to ammonia which is directly usable

Front 37

Which Gram bacteria have perisplasms?

Back 37

-only Gram-
*See slide in EM near end for diagram

Front 38

How does the sulfur cycle work?

Back 38

-elemental to sulfate (this can go to H2S which isn't useful forming a circle)
-sulfate up to prokaryote proteins, up to animal proteins, up to dead organism proteins
-these proteins go to H2S which gets cycled back across to starting point of environ sulfur

Front 39

What is the most usable form of sulfur?
How do you get elemental sulfur from sulfide?

Back 39

-sulfate
-oxidize it

Front 40

What is important about the phosphorus and trace mineral cycle?

Back 40

-it doesn't undrego redox reactions

Front 41

What occurs during the phosphorus cycle?

Back 41

-phosphorus undergoes little change in oxidation state in environment
-movement from insoluble to soluble forms
-conversion from organic to inorganic forms by pH dependent processes

Front 42

What is important (or happens) in cycling of trace minerals?

Back 42

-metal ions are important microbial nutrients
-cycling primarily invovles a transition from an insoluble to a soluble form so they can be used by organisms

Front 43

What is different (but still acceptable) about Iron in the environment?

Back 43

-oxidizing Fe will yeild energy, but not much. Organisms will still be able to live there however (just enough)
-need acidic environment

Front 44

Where is Iron found often (what does it come from)

Back 44

-pyrite (FeS2) found around coal/metal mines
-when mixed with air, oxidation occurs spontaneously resulting in sulfuric acid (and therefore your acidic environment!).