biotechnology Flashcards
what are the living organisms most commonly used in biotech?
bacteria & fungi
why are bacteria & fungi most commonly used?
- short life cycle = grow rapidly, form products quickly
- ideal growth conditions easily created
- grow at any time of year
what is bioremediation?
process of using organisms to remove pollutants from contaminated sites
how does bioremediation work?
stimulates growth of suitable microbes that use contaminants as food source
describe the conditions required for bioremediation
- water available
- suitable temperature
- suitable pH
what modifications are made when bioremediation conditions are not suitable?
- addition of substances such as molasses to provide nutrients for effective growth
- pump oxygen for aerobic bacteria
summarise the advantages of bioremediation
- uses natural systems
- less labour/equipment
- few waste products
- less risk of exposure to people from clean ups
what is an example of large scale culturing?
fermenter/bioreactor
what is an example of small scale culturing?
growing on agar gel using petri dishes
what is a culture?
population of one type of micro organism that has been grown under controlled conditions
state the 2 main methods for culturing micro organisms
- batch fermentation
- continuous fermentation
what is contained in the culture medium?
- water & minerals
- increases product yield because micro organisms can always access nutrients for growth
what is the purpose of the paddles in the culture medium?
stops cells settling at the bottom
- allows all micro organisms to access nutrition & oxygen
describe the process of batch fermentation
- micro organisms grown in individual batches
- in a fermentation vessel
what is the purpose of oxygen supply?
- oxygen volume kept at optimum level for respiration
- pumps sterile air into vessel
- increases product yield because micro organisms can always respire to provide energy for growth
what is the purpose of the pH monitoring?
- monitored by pH probe
- increases product yield because enzymes can work efficiently so rate of reaction is high
what is the purpose of the water jacket on the fermentation vessel?
- keeps temperature at optimum
- increases product yield because enzymes can work efficiently so rate of reaction is high
what is the purpose of sterilising the fermentation vessel?
- uses superheated steam to kill unwanted organisms and ensure next culture is not contaminated
- increases product yield because micro organisms aren’t competing with other organisms
describe the process of batch fermenting
- sterilise vessel
- set up culture
- ferment for a week
- do not add nutrients
- do not waste products
- may add O2 - sterile air - if not brewing
- empty vessel, harvest & purify
- set up again
- reach stationery phase as product is a secondary metabolite
describe the process of continuous fermentation
- sterilise vessel
- set up culture
- ferment for 5 years unless contaminated
- continuously add nutrients and remove waste products
- continuously add O2 and remove CO2
- continuously harvest & purify products
- keep in log phase / exponential as product is a primary metabolite
give an example of batch fermentation
culturing mould to produce penicillin
give an example of continuous fermentation
using GM e coli to produce insulin
what is meant by ‘secondary metabolite’ ?
only produced once population has reached a certain size
