4. Digestion of Food
> The useful bacteria in human intestine make vitamins such as
vitamin K and vitamin B.
Decomposition and Recycling of Materials
> Saprophytic bacteria and fungi release enzymes that help to break
down complex organic matter in dead organisms into simpler
substances by decomposition.
Medicines and Health Supplements
> Antibiotics, e.g. penicillin (an antibiotic) which is widely used to
kill bacteria that cause various diseases.
> Vaccine consists of dead/weakened harmful microorganisms that is
injected/swallowed into human body in turn produce antibodies to
fight the disease caused by the harmful microorganisms.
Agriculture
> In making composts.
> Biological control
Industries
> Making bread
> Brewing alcoholic drinks
> Making animal skins
