Microbial Biotechnology and Bioproducts

Question 1

what is a pure culture?

Answer 1

a culture of a species that has been isolated from nature and is grown under well controlled conditions

Question 2

what is a primary metabolite?

Answer 2

A primary metabolite is a kind of metabolite that is directly involved in normal growth, development, and reproduction.

Question 3

give some examples of prim. metabolites

Answer 3

• potable alcohol
• barley
• other things that contain starch

Question 4

how is potable alcohol made?

Answer 4

• starch (yeast can’t assimilate) reacts w/ BARLEY ENZYMES in reactor
• creates LOW MOLECULAR WEIGHT SUGARS (eg glucose+ disaccharides + trisaccharides)
• react w/ YEAST (Saccharomyces) O produces ETHANOL

Question 5

what happens when grapes grow?

Answer 5

malic acid DECREASES and is converted to SUCROSE

sucrose INC (storage compound)

malic acid:sucrose
DECREASES

sucrose:total grape biomass ratio INC

Question 6

why is it important to have enough sugar for the formation of potable alcohol?
O why is it important to know the metabolic pathways in yeast for the production of ethanol?

Answer 6

• the correct sugar:acid ratio is essential for the yeast to grow (they need sugar for growth)
• yeast is needed for the conversion of sugars to ethanol
• imp to know the m.p of yeast so we can optimise production of ethanol

Question 7

why is alcohol produced?

Answer 7

• ethanol is the final product of ENERGY METABOLISM in ANAEROBIC fermentation
• these act as ‘e- sinks,’ allowing cells to cont with their metabolic activities and BALANCING REDOX STATES

Question 8

what are some other final products of anaerobic fermentation?

Answer 8

• butanol
• acetone
• lactic acid
  (much more reduced compounds than glucose)

Question 9

why are products like ethanol produced in anaerobic ferm?

Answer 9

O is not present to be the FINAL E- ACCEPTOR O something else must act as an electron sink

Question 10

what are the uses of ethanol?

Answer 10

• biofuel

- solvent

Question 11

what can the bacterium Clostridium be used to produce? under anaerobic cond

what are they used for?

what is an advantage of using bacteria to obtain these?

Answer 11

• bioacetone
• biobutanol
  -bioethanol
  INDUSTRIAL USES

Adv is that:
- less crude oil used

Question 12

what conditions does Clostridium require?

Answer 12

• it is an obligate anaerobe

Question 13

why may using bac/yeast not be economically viable?

Answer 13

• gathering raw material may be expensive

Question 14

uses of a.a?

Answer 14

• to correct dietary deficiency diseases

- as components of processed food (eg monosodium glutamate)

Question 15

give two ways a.a can be produced

Answer 15

• hydrolysis of proteins

- use microorg ( more specific)

Question 16

what can be done to reduce the amount of a competing product?

Answer 16

metabolic pathway engineering- create a MUTANT that is AUXOTROPHIC for the competing product

Question 17

why do some bacteria need biotin (vitamin) ? what is the importance of this for production?

Answer 17

can cause cell memb to become leaky

allows product to diffuse out of cell O it won’t inhibit its own overproduction. cell can still grow

Question 18

uses of organic acids (eg citric acid)

Answer 18

• acidulant in food/drink
  manufacture
• plastics manufacture
• processed cheese manufacture

Question 19

how can fungi be used to produce organic acids?

Answer 19

• grow in liquid cultures
• limited O conditions
• excrete organic acids

Question 20

when Aspergillus fungi are inoculated in liquid culture what are the two things that can be formed?

Answer 20

1- homogenous filamentous morphology

2- pellets (islands of growth) containing many morphologies

Question 21

how does oxygen conc vary IN a pellet?

Answer 21

high conc in liquid (outside pellet)

• at centre of pellet culture is ANAEROBIC
• edge cells are AEROBIC

Question 22

how does O conc in a pellet effect the Krebs cycle?

Answer 22

• edge of pellet = enough O = fully functional Krebs

- centre of pellet= ANAEROBIC= interrupted Krebs O start excreting CITRIC ACID

Question 23

what is acetic acid?

Answer 23

vinegar

Question 24

how is acetic acid formed?

Answer 24

yeast used to produce ethanol—oxidised by ACETOBACTER bacteria to ACETIC ACID

Question 25

what is a use of acetic acid in industry?

Answer 25

SOLVENT

Question 26

what is the traditional source of polysaccharides?

Answer 26

seaweed

Question 27

which bacteria is used in polysaccharide production? where is it found/what does it do?

Answer 27

Xanthomonas- a plant pathogen

Question 28

what are the uses of polysaccharides?

Answer 28

- food industry (inc viscosity) | - enhance OIL RECOVERY ( inc viscosity of WATER- O oil can float of top)

Question 29

why does Xanthomonas need to make polysaccharides?

Answer 29

- when PHOSPHOROUS sufficient it is SUGAR used to grow to make ATP etc - when LOW PHOSPHOROUS, Xanothomonas make POLYSACCHARIDES to store

Question 30

what cond does Xanthomonas make polysaccharides?

Answer 30

Phosphorus deficient

Question 31

what are the uses of lipids?

Answer 31

- dietary additives to correct deficiency diseases | - polyhydroxybutyrate makes BIOPLASTIC synthesised by ALCALIGENES spp.

Question 32

what happens to Alcaligenes spp. under phosphate deficient cond?

Answer 32

produce POLYHYDROXYBUTYRATE because cell cannot utilise phosphate to produce ATP. O Polyhydroxybutyrate is a STORAGE compound

Question 33

what fungus can be forced to overproduce alpha-amylase enzyme in the process of making products like high fructose syrup? what is the reaction?

Answer 33

starch( from cereal crop- glucose polymer)-------mono/di/trisaccharides via ALPHA AMYLASE using ASPERGILLUS FUNGUS

Question 34

what fungus can be forced to overproduce amyloglucosidase enzyme in the process of making products like high fructose syrup? what is the reaction?

Answer 34

mono/di/trisaccharides-------glucose via AMYLOGLUCOSIDASE using ASPERGILLUS FUNGUS

Question 35

what fungus can be forced to overproduce glucose isomerase enzyme to make products like high fructose syrup? what is the reaction?

Answer 35

glucose------high fructose syrup (glucose + fructose) via GLUCOSE ISOMERASE using BACILLUS

Question 36

why is the overproduction of enzymes better that using chemicals to go from starch--->sucrose?

Answer 36

- dirty | - expensive

Question 37

how are enzymes used in laundering? how are the enzymes with specific properties used in laundering?

Answer 37

- highly specific properties - heat labile - wide variety of substrates - unaffected by detergents

Question 38

how do you obtain enzymes w/ the specific properties for laundering?

Answer 38

engineered by chaninging growth cond.

Question 39

how are enzymes used in the chemical ind?

Answer 39

- to conduct reactions that are diff w/out enzymes

Question 40

what are single cell proteins?

Answer 40

bacterial, yeast or fungal cells for human/animal consumption

Question 41

what was the origin of single cell proteins?

Answer 41

- oil refineries (convert crude oil to refined oil using microbiological processes) - but HIGH YIELD & thought there may be a famine O switched objective to food production

Question 42

give an example of food product made by fungi

Answer 42

Quorn , Fusarium

Question 43

what are the majority of pharmaceutical products produced by micro org?

Answer 43

antibiotics

Question 44

what is the economic imp of micro products in pharmacy?

Answer 44

one of biggest industries in the world

Question 45

when does secondary metabolism kick in?

Answer 45

when 1 or more nutrients are exhausted

Question 46

what could be a product of secondary metabolism?

Answer 46

antibiotics

Question 47

how can you control the composition of your medium? why would you do this?

Answer 47

C limited, N limited or P limited media because diff limitations trigger synthesis of diff compounds ~ generally similar limitations trigger synthesis of similar classes of antibiotics

Question 48

describe how antibiotic production varies w/ biomass inc and substrate conc

Answer 48

biomass INC EXPONENTIALLY until it slows substrate DECREASE as substrate DEC v low, ANTIBIOTIC INC suddenly O SECONDARY METABOLISM has begun

Question 49

what fungi produces filamentous fungi?

Answer 49

Penicillium chrysogenum

Question 50

how can you obtain different types of penicillin using secondary metabolites?

Answer 50

alter the precursor eg phenyl acetic acid

Question 51

how can semi synthetic penicillins be obtained?

Answer 51

chemically synthesise a side chain

Question 52

what are the two diff phases of secondary metabolite production? describe what happens in them

Answer 52

1) GROWTH - rapid growth - glucose = C source - 30 degrees - no precursor 2) PRODUCTION - slow growth - slowly assimilated C source - lower temp - precursor feed

Question 53

how does Penicillin work?

Answer 53

- prevents formation of bacterial cell wall O easily lysed

Question 54

give examples of how some other (non Penicillin) ABs work?

Answer 54

- prevent protein synthesis using bacterial ribosomes (SPECIFIC DUE TO BAC HAVING DIFF RIBOSOME STRUCTURE) - some target the cell memb (not v bacterial specific) - some affect cell metabolism (not v bacterial specific) - some affect nucleic acid replication (not v bacterial specific as this mechanism is UNIVERSAL)