What are harmful effects of microorganisms …

Harmful effects of microorganisms:
Bacteria: Causes various diseases such as typhoid, diarrhea, and cholera.
Fungi: Causes a large number of diseases in plants and in animals such as rust diseases in plants, fruit rot in apple, red rot in sugar cane and ring worm disease in human beings.
Algae: Algal boom in water (rapid growth of algae) causes poisonous effect after they die, which in turn results in the death of aquatic organisms.
Protozoa: Causes Amoebic dysentery, pyorrhoea and sleeping sickness etc.
Virus: Cause small fox, common cold, influenza, herpes, hepatitis, polio and rabies.
Useful effects of microorganisms
Bacteria: In industries, they are needed to make curd, cheese, vinegar, lactic acid, alcohol and even in ripening of tea leaves, etc.
Fungi: Some useful fungi are yeast, used to make dough in bakery and alcohol etc. Some fungi are useful for preparing antibiotics. Some mushrooms which are useful in making vitamins and organic acids.
Algae: Some useful algae are chlorella (produce protein and vitamin), red algae (agar) and brown algae (Iodine and potassium).
Protozoa: Some help in the final degradation of waste and sewage while some are symbiotic in nature.
Virus: They are used for scientific research such as in biotechnology, genetic engineering, gene therapy and for making antibiotics etc.