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CELS Microbiology > Microbes > Flashcards

Flashcards in Microbes Deck (54)
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1

what 3 things do microbes need to grow

carbon source, energy source and reducing power (electrons)

2

photoautotroph

energy = light, carbon = CO2

3

chemoautotroph

energy = chemical compounds, carbon = CO2

4

photoheterotroph

energy = light, carbon = organic compounds

5

chemoheterotroph

energy = chemical compounds, carbon = organic compounds

6

phases of prokaryote growth in a ‘closed’ batch culture system

Lag phase - time is required to get biosynthetic reactions running. Exponential phase - cells are actively dividing through binary fission and nothing is limiting growth. Stationary phase - resources run out so cells stop multiplying and cryptic growth takes place (when they survive by consuming other dead cells). Death phase - 90% of population dies and waste and toxins accumulate

7

contradictions to bacteria norms

cooperative feeding, form fruiting body of many cells in unfavourable conditions, contain complex internal organs

8

mesocosm

an experimental system that simulates real like conditions as closely as possible

9

enrichment culture

providing temp and chemical conditions in lab that encourage growth of specific organisms

10

what does winogradsky column require

water, light, sediment, CaCO3 and CaSO4 and cellulose

11

order of layers of winogradsky column

cyanobacteria, colourless sulfur bacteria, purple sulfur bacteria, green sulfur bacteria, sulfate-reducing bacteria, cellulose degrading

12

cyanobacteria

oxygenic, photoautotroph, e- donor = H2O, C source = CO2, acyclic phosphorylation

13

colourless sulfur bacteria

anoxygenic, chemoautotroph, e- donor = H2S, carbon source = CO2

14

purple sulfur bacteria

anoxygenic, photoautotroph, e- donor = H2S, carbon source = CO2, cyclic phosphorylating in anoxygenic photosynthesis

15

green sulfur bacteria

anoxygenic, photoautotroph, e- donor = H2S, carbon source = CO2, cyclic phosphorylating in anoxygenic photosynthesis

16

sulfate-reducing bacteria

chemoheterotroph, e- donor = sulfate, carbon source = organic carbon, products = H2S and CO2, cause high gradient of H2S at bottom of column

17

cellulose-degrading bacteria

chemoheterotroph, e- donor = organic carbon, carbon source = glucose/pyruvate, products = acidic so low pH at bottom

18

what causes high sulfur conc at bottom of column

sulfate reducing bacteria producing sulfur

19

what causes high O2 conc at top of column

acyclic phosphorylation in oxygenic photosynthesis

20

how do different layers overcome problem of lack of light

adapt to absorb different wavelengths of light

21

anoxygenic photosynthesis

photosynthesis without production of of oxygen

22

oxygenic photosynthesis

photosynthesis with production of oxygen

23

microbial ecology

study of interrelationships between organisms and their environment

24

role of heterotrophs in the carbon cycle

heterotrophic microorganisms are the primary biomass recyclers on the planet

25

primary treatment in water treatment

  1. Purely physical processes
  2. 60% contaminants removed
  3. Waste water is pumped through a sieve to remove indestructibles
  4. Moves into sedimentation tank
    • Sludge at the bottom - incinerated
    • Water - ocean

26

secondary treatment in water treatment

  • Microbes
  • 95% of contaminants removed- used on top of primary treatment
  • Instead of water being pumped into the ocean straight away, moved through aeration tankà aerobic microbes decompose
  • Liquid then move into settling tanksà flocs (activated sludge) form and then moves back into aeration tank
  • Residual sludgeà anoxic sludge digesterà anaerobic microbes decompose sludge

27

tertiary treatment of water

  • anything beyond secondary
  • involves chemical treatment e.g. UV, chlorine

28

objectives of water treatment

  • kill pathogens in water
  • reduce organic, nitrogen and phosphorous load
  • produce a disposable effluent without causing harm to the surrounding environment

29

biochemical oxygen demand

  • relative amount of dissolved oxygen consumed by microbes to aerobically decompose all organic material in a water sample
  • polluted water has higher BDO than pure water bc more organics present so more O2 required to break down

30

what is a dead zone + examples

  • When the oxygen concentration in water has fallen so low animals can no longer survive
  • More likely to occur at higher temperatures
  • Dead zone examples: Black sea, Gulf of Mexico