microorganisms&biotechnology Flashcards
define biotechnology
applying biological organisms, enzymes to the breakdown of materials to benefit people (agriculture or medicines)
why are micro organisms ideal to use?(4)
no welfare issues to consider,
a large range of them could be used
can be artificially manipulated to carry out reactions they wouldnt normally do
short life cycle and rapid growth rate
advantages of using microorganisms for food (4)
can be grown quick easy and cheap as they have simple growth requirements (low temp, removal of waste gases, supply of food and oxygen)
fast reproduction rates
can be GM to produce the proteins required
can be grown anywhere
disadvantages of using microorganisms (3)
if conditions are not maintained, some microorganisms can produce toxins
need carefully controlled sterile conditions
people dont like the idea of eating microorganisms grown on waste
what conditions do microorganisms need to be cultured? (4)
food
pH
temp
oxygen
inoculating broth (liquid nutrient medium) (4steps)
make a suspension of the bacteria
mix a known volume with sterile nutrient broth in the flask
put a stopper in the flask to prevent contamination
incubate at a suitable temp and shake regularly to provide oxygen for the growing bacteria
inoculating agar(solid form of nutrient medium) (4steps)
inoculating loop must be sterilised (avoid touching cool surfaces to avoid contamination)
dip the loop into a bacterial suspension (avoid digging it into the agar)
replace the lid of the petri dish and hold it down with tape but not sealed completely to allow oxygen in
incubate at a suitable temp
benefits of using isolated enzymes over microorganisms? (3)
less wasteful (do not use up substrate)
no unwanted enzyme present
pure product is produced (microorganisms give a variety of products so isolating is difficult and expensive)
immobilised enzymes
enzymes attached to a support system that the substrate passes over and is converted to product
these can be reused
benefits if using immobilised enzymes
reused - cheap
more reliable - highly controlled
greater temp tolerance
disadvantages of immobilised enzymes
reduced efficiency
high initial costs of materials
high initial cost of bioreactor (system used)
4 ways of immobilising enzymes
absorption (bound to the surface of insoluble materials)
bound to the surface of insoluble materials through ionic or covalent bonding
entrapment into the matrix
encapsulated (behind a semi permeable membrane)
culture
a population of one type of microorganism thats been grown under controlled conditions
why are cultures grown in fermentation vessels? (2)
either obtain lots of microorganisms
or collect lots of useful products that they use
two main methods for culturing microorganisms
batch fermentation
continuous fermentation
