Answer:
HEALTH SECTOR(microorganisms have led to the most devastating diseases of man such as HIV VIRUS, HEPATITIS VIRUS, SALMONELLA TYPHI AND PARATYPHI SPPS)
INDUSTRY(microorganisms have led to masses losses due to contamination of foods like the GROWTH OF MOLDS)
ENVIRONMENT most contamination of the environment are caused by microorganisms.
Explanation:Louis Pasteur meant that with the microscopic nature of microorganisms they have been able to make great impact in the world.
IN THE HEALTH SECTOR Microorganisms have been the major cause of the diseases of human and animals world wide, diseases such as Hepatitis A,B,C Virus,Typhoid caused by Bacteria (Salmonella typhy and paratyphy spp) etc have been a cause of a huge number of death.
INDUSTRY
Microorganisms are major causes of loss in the industries leading to large scale contamination of food products, such as Fungi infestation on foods especially of plants origin. MICROORGANISMS ALSO HAVE BENEFITS IN THE INDUSTRY AS IT IS USED IN THE FERMENTATION OF FOOD PRODUCTS.
IN THE ENVIRONMENT
Microorganisms are the major cause of environmental hazards such as the contamination of water bodies, the air (THE HUMAN FLU VIRUS) etc ALL THESE MICROORGANISMS HAVE CAUSED MASSIVE DEATHS THE WORLD OVER.