Food production: e.g., Lactobacillus used in yogurt, maas, cheese production; vinegar fermentation of ethanol
Saprophytes/decomposers: involved in recycling nutrients, removal of dead bodies, decomposition of sewage
Genetically modified bacteria: play a role in the nitrogen cycle, produce antibiotics, insulin, etc
Harmful bacteria:
Pathogens: cause diseases by damaging host cells or producing toxins (e.g., TB, cholera)
Food spoilage and poisoning: caused by saprophytes decomposing food and forming toxins ingested with the food, leading to food poisoning (e.g., botulism)
Bacterial DNA plasmids are used in bio-engineering to produce insulin
Recombining genes in micro-organisms is used to produce hormones like human growth hormone, vaccines such as hepatitis B, and interferon used in AIDS treatment
Antibiotics work to destroy bacteria by stopping them from forming cell walls or making proteins and nucleic acids, altering the permeability of the cell membrane, causing bacteria to lose vital substances
If antibiotics are overused or used incorrectly, bacteria become resistant through DNA mutations, leading to superbugs that are resistant to all known antibiotics
Fungi are used in the manufacture of food like bread, cheese, and beer, as a food source, for recycling nutrients in the soil, and to manufacture antibiotics like penicillin
Pathogenic fungi cause diseases in humans and animals, while fungi like potato blight, mildew, and rust lead to food crop losses, poverty, famine, and death
Protozoa carry out about half of the carbon fixation in the world, regulate the gas balance in the atmosphere, and can form harmful toxins like red tide that make seafood poisonous