cloning and biotechnology

uses for microorganisms

• food

• medicine

• bioremediation

food as a use of microorganisms :

indirect :

• baking

• brewing

• cheese

• yoghurt

direct :

• quorn

medicines as a use for microorganisms :

• penicillin

• insulin

bioremediation as a use of microorganisms :

• natural processes

• genetically modified organisms

brewing :

• yeast respires anaerobically (fermentation)

• called Saccharomyces cerevisiae

• glucose (sugar) = ethanol + carbon dioxide

• C6H12O6 = 2C2H5OH + 2CO2

• malting

• mashing

• fermentation

• maturation

• finishing

malting during brewing :

• barley germinates

• enzymes break down starch into sugars which yeast can then respire

mashing during brewing :

• malt mixed with hot water (55-65C’)

• enzymes break down starch producing wort

fermentation during brewing :

• yeast added to wort

• fermentation occurs

• yeast eventually killed as pH lowers

• ethanol builds up

• oxygen decreases

maturation during brewing :

• beer conditioned for 4 to 29 days

• at 2-6 degrees

finishing during brewing :

• beer filtered

• pasteurised

• and packaged

baking :

• uses yeast (Saccharomyces cerevisiae) which respires aerobically

• carbon dioxide is produced causing the bread to rise

• glucose + oxygen = carbon dioxide + water

process of baking :

• active yeast mixture added to flour and other ingredients

• left in warm environment

• excess air removed from dough

• dough kneaded, shaped and allowed to rise again

• cooked in hot oven

• CO2 bubbles expand

• yeast cells killed during cooking

cheese making :

• bacteria converts the sugar lactose in milk into lactic acid

• uses lactococci and lactobacilli etc..

process of cheese making :

• milk is pasteurised at 95 degrees for 20 secs

• kills off natural bacteria

• milk is homogenised to evenly distribute fat droplets

• bacteria and chymosin enzymes are added to help clot the milk

• milk separates into solid curls and liquid whey

• cottage cheese - curds packaged and sold

• harder cheese - curds cooked in whey and strained using a cheese cloth to be packaged or matured

• whey - used to feed animals

yoghurt production :

• bacteria feed on milk sugar called lactose to produce lactic acid

• uses the bacteria Streptococcus thermophilus and Lactobacillus bulgaricus

process of yoghurt production :

• equipment sterilised - heated at 71 degrees for 20 secs

• milk is pasteurised

• bacteria culture is added and incubated

• yoghurt sampled

• flavour, colour is added and packaged

• quality control occurs

• some culture is taken to add to the next batch

what is biotechnology?

applying biological organisms or enzymes to the synthesis, breakdown or transformation of materials in the service of people

advantages of using microorganisms

• no welfare issues

• huge range of suitable microorganisms

• genetic engineering allows the manipulation of microorganisms to produce otherwise unlikely products e.g. human insulin

• short life cycle

• rapid growth rate

• nutrient requirements very minimal and cheap

indirect food production :

• used in biotechnological processes to produce food

• microorganisms have an important impact on other food

• baking

• brewing

• cheese

• yoghurt

direct food production :

• e.g. quorn - a fungus

• single cell protein

• grown in large fermenters using glucose syrup as a food source

advantages of using microorganisms to produce human food :

• reproduce and produce protein quickly

• high protein content with little fat

• uses waste products from humans and animals reducing cost

• can be genetically modified

• flavours can be added

• not dependent on weather

• no welfare issues

disadvantages of using microorganisms to produce human food :

• some may produce toxins

• must be separated from nutrient broth to make food

• needs carefully controlled sterile conditions

• concerns with genetic modification

• protein must be purified

• lacks flavour

penicillin :

• first effective antibiotic

• produced by the mould Penicillium notatum

• later penicillium chrysgenum used to produce a bigger yield

• needs high oxygen levels and rich nutrients

• pH and temperature must also be monitored

process of producing penicillin :

• uses small small fermenters to maintain high levels of oxygenation

• mixture continuously stirred

• rich nutrient medium present

• growth medium contains a buffer to maintain pH of 6.5

• bioreactors maintained 25-27*C

industrial uses of immobilised enzymes :

• glucose isomerase

• penicillin acylase

• lactase

• aminoacylase

• glucoamylase