6.2.1 biotechnology Flashcards
define biotechnology
the use of living organisms in the production of useful products like food and drugs or carrying out sewage disposal
define primary metabolite
- any substance produced by a microorganism during its normal metabolism and growth
bacteria and fungi
secondary metabolite
and substance produced by a microorganism once it has stopped growing
why are microorganisms ideal for use in biotech?
- no welfare issues
- easy to create optimum growth conditions
- huge rage of diff species of microbes= can carry out lots of diff reactions
- microbes easy to modify ( genetic engineering)
describe how yeast is used in baking
- single felled fungus
- respires anaerobic ally
- releases CO2
describe how yeast is used in brewing
- respires anaerobically
- produces CO2 and ethanol
what does amylase do?
- converts starch into maltose
- yeast used this for resp to produce ethanol and CO2
why is milk pasteurized?
to remove pathogens
why does production of yogurt stop at pH 4.3?
low acidic pH which inhibits enzyme activity in bacteria
bacteria then die
advantages of using microorganisms to produce human food
- reproduce fast
- high protein content with little fat
- can use waste materials = reduces cost
- microorganisms can be genetically modified to produce protein required
- no welfare issues
- can be made to taste like anything
disadvantages of using microorganism to produce human food
- produce toxins if conditions not optimum
- more downstream processing
- sterile / aseptic conditions = expensive
- needs to be purified
- little natural flavour
what does penicillin need to grow?
- high conc of oxygen and nutrients
- grown in small batches in small fermenters
why are small fermenters used to produce penicillin?
large fermenters are too hard to keep oxygenated
define batch fed
nutrients are added at regular intervals rather than just as start
state factors that need to be controlled inside the fermenter
- well oxygenated so that aerobic conditions can be maintained
- waste gases let out to reduce pressure
- optimum temp and ph so enzymes don’t denature
why is penicillin a secondary metabolite?
it is produced after the fungus has stopped growing
describe downstream processing
- purifying product harvested from fermented before it is fit for human use
- separating out useful products from contaminated
- concentrate product
importance of maintaining aseptic conditions
- avoid unwanted microbes
- no competition for nutrients
- no decrease in yield
- conditions remain unchanged
- no contamination of batch
why are fungi secondary metabolites?
- once fungus has grown and established itself it is useful to produce antibiotics to inhibit growth of any nearby competing bacteria (which may compete for limited resources)
what is bioremediation?
use of microorganisms to remove toxic substance / pollutants from the environment that could otherwise accumulate in food chains causing hard to living organisms
2 ways bioremediation is used
- natural organisms used - break down organic matter to co2 and H2O
- GM organisms - GM bacteria break down/ accumulate contaminants
what must a culture medium contain? (5 things)
- energy source (microbes use sugars for resp to make atp)
- carbon source ( make organic molecules)
- nitrogen source ( make a.a, proteins, DNA, RNA)
- mineral ions: vitamins (hormones)
- water (all reactions take place in aq solution and movement of molecules)
what is turbidity?
how cloudy/thick/ viscous mixture is
more turnout means what?
more growth causes more turbidity so mixture difficult to stir and difficult to evenly distribute nutrients and oxygen
aseptic techniques
- disinfect surfaces
- light bunsen - hot air roses - microbes drawn away
- sterilize instruments used
what does it mean by microbes are grown in a closed culture?
isolated from external environment, no extra nutrients added + no waste products removed
what happens in the lag phase ?
-bacteria adapting to new environment
- synthesizing enzymes needd
- slow increase
log phase
rate of bacteria produced increasing rapidly (theoretical max)
stationary phase
growth rate = 0
death stage
death rate exceeds reproduction rate
describe why sugar concentration decreases as ethanol concentration increases
- the sugar is converted to ethanol in anaerobic resp
- sugar loses CO2
- as sugar conc decreases biomass increases
batch fermentation
- closed culture
- individual batches
- sterile nutrients
- nothing added or removed
- for secondary metabolites
- forces microorganisms to enter stationary phase where growth stops
continuous fermentation
- sterile nutrients
- as microbe grows keep on adding nutrients and removing product
- primary metabolites
- microbes kept in log stage so they fit. run out of nutrients and waste products don’t build up
- continue with normal growth and metabolism
generation time equation
generation time (G) = time (t) / number of generations (n)
advantages of immobilized enzymes
- less downstream processing
- reusable - costs less
- greater temp tolerance - don’t denature at high temps
- works at changed pH
- continuous process - bioreactor kept running for long time- without emptying or cleaning - cheaper
