Microbiology General

Question 1

Where do autotrophs get carbon from?

Answer 1

CO2

Question 2

Where do hetertrophs get carbon from?

Answer 2

Carbon for organic compounds

Question 3

Where do phototrophs get energy from?

Answer 3

Light

Question 4

Where do chemotrophs get energy from?

Answer 4

Chemical compounds

Question 5

What is the energy source and carbon source of photoheterotrophs?

Answer 5

Light. Organic compounds.

Question 6

What is the energy source and carbon source of photoautotrophs?

Answer 6

Light. Carbon dioxide.

Question 7

What is the energy source and carbon source of chemoheterotrophs?

Answer 7

Usually organic compounds. Organic compounds.

Question 8

What is the energy source and carbon source of chemoautotrophs?

Answer 8

Usually inorganic compounds. Carbon dioxide.

Question 9

Describe the main features of microbial metabolism.

Answer 9

• Large number of biochemical pathways

- Don’t require oxygen as terminal electron acceptor

Question 10

What is an anabolic reaction?

Answer 10

‘building up’

Question 11

What is a catabolic reaction?

Answer 11

‘breaking down’

Question 12

What are the 2 main reactions in microbes that yield energy?

Answer 12

Respiration and fermentation

Question 13

Describe respiration in microbes.

Answer 13

• Electron transport chain
• Microbes don’t just use oxygen
• ANaerobic
• Use another suitble oxidant
• Requires a modified ETC in order to transport electrons to new acceptors

Question 14

Describe fermentation in microbes.

Answer 14

• Breaking down organic compounds without respiration
• Organic compounds serve as both electron donors and electron acceptors
• Fermentable substrances including carbohydrates, organic acids and amino acids
• Usually involves converting pyruvate to final products

Question 15

What do unusual pathways mean for microbes?

Answer 15

Can survive in lots of different environments.

Question 16

What is meant by biogeochemical?

Answer 16

• Modified conditions on earth
• Cyanobacter produced oxugen
• Carbon cycle
• Nitrogen cycle

Question 17

What is the mycorrhizae?

Answer 17

Mutualistic relationship between fungi and plant and roots

Question 18

Describe mycorrhizae

Answer 18

• Fungus integrated into structure of root
• Highly specific and organised
• Fungus gets carbon
• Plants get P and N
• Enhanced uptake of water
• Increases length of feeder roots
• Increased tolerance to conditions
• Resistance to pathoens
• Tolerance of toxins

Question 19

What are the two types of Mycorrhizae?

Answer 19

Ectomycorrhizae. Endomycorrhizae.

Question 20

What is Ectomycorrhizae?

Answer 20

grow over root surface, common is gymnosperms and angiosperms

Question 21

What is Endomycorrhizae?

Answer 21

penetrate into plant root cells, non-pathogenic, form intracellular coils

Question 22

Describe the interaction of lichens.

Answer 22

• Symbiosis between fungi and algae or cyanobacteria
• Mutualism
• Fungi is consumer
• Algae/cyanobacteria is producer

Question 23

Why do fungi and animals have mutualistic relationships?

Answer 23

Cellulose is abundant by herbivores can’t digest it. Rely on enzymes produced by fungi

Question 24

What are Ruminants?

Answer 24

Contributes to the digestion of cellulose.

Question 25

What are the origins of fermentation?

Answer 25

Beer

Question 26

Why are microbes good in biotechnology?

Answer 26

- Lots of different microbes with different pathways - Small size - High surface to volume ratio - High metabolic rate - Adapted to a broad range of environments

Question 27

What are the 3 main reasons microorganisms are used industrially?

Answer 27

1. Cells 2. Bioconversion 3. Product from cells

Question 28

Why are cells used industrially?

Answer 28

Growing to do something with eg protein source or bacterial vaccines

Question 29

Describe cells being used for protein.

Answer 29

Primarily animal consumption, Quorn or mycroprotein, Energy conversion is much better

Question 30

Describe cells being used for bacterial vaccines.

Answer 30

Living - anthrax. Inactivated (using antigens) - meningitis

Question 31

What is bioconversion?

Answer 31

Put in a substrate goes through an enzymatic processor into a product

Question 32

Describe features of biocovnersion

Answer 32

- Rely on enzymes - Low temps - In aqueous media - Few if any side products - Very specific

Question 33

What are the different products from cells that can be used?

Answer 33

Enzymes. Primary metabolites. Secondary metabolites.

Question 34

Why do we need enzymes?

Answer 34

- Biological catalysts - Food and chemical industries - Increases specificity, efficiency - In washing powders

Question 35

Why do we need primary metabolites?

Answer 35

- Amino acids, purines, vitamins, organic acids - Exponential phase - Huge quantities - Nutritional and genetic manipulations

Question 36

Why do we need secondary metabolites?

Answer 36

- Produced under disruption - Antibiotics, toxins and alkaloids, plant growth factors - Diverse - Lots of antibiotics out there

Question 37

What can be used for large scale production?

Answer 37

Fermenters

Question 38

Describe a fermenter

Answer 38

- Most use broth - Closed vessel = pure culture - Glass or stainless steel - Smooth - No sharp corners - Withstand high temperatures

Question 39

How do we control the temperature in a fermenter?

Answer 39

- Cooling equipment eg cooling jack or coil of pipe to pump water through - Metabolic reactions will release energy so need to cool it down

Question 40

Why and how do we stir in a fermenter?

Answer 40

- Stirring paddles - Baffles to stop bulk movement - No stagnant areas

Question 41

Why and how do we use areation in a fermenter?

Answer 41

- Aerobic - Sparger - Oxygen supplied as air (sterile) - Filtration - Reduces rate limiting factors, oxygen should never be limiting - Makes air disperse in small bubbles

Question 42

How do we monitor conditions in a fermenter?

Answer 42

temp sensors (resistance thermometers), pH electrodes, foam → anti-foams to prevent foam formation

Question 43

How is a fermenter sterilised?

Answer 43

Vessel injected with steam - shut valves and add steam. Builds pressure.

Question 44

How is a fermenter innoculated?

Answer 44

Stock cultures in optimal growth → repeated at 20 fold increases Large population to work on product Dilute and swamp any contamination

Question 45

What are the features of batch fermentation?

Answer 45

Good for secondary metabolites. Doesn't provide ideal growth conditions all the time

Question 46

What are the 2 controls in continuous fermentation?

Answer 46

Turbidostat control and Chemostat control

Question 47

Describe Turbidostat control.

Answer 47

Rate at which cells leave the reactor vessel governs the rate at which fresh nutrients enter

Question 48

Describe chemostat control.

Answer 48

Look at flow of nutrients → look at limiting rate of reaction

Question 49

What are the main features of downstream processing?

Answer 49

``` Location of product Concentration of product Physical and chemical products Removal of solids Primary isolations Distillation Precipitation ```