Types of Microorganisms

Characteristics of Microorganisms

• Microorganisms, or "microbes", are small living things that are found nearly everywhere on Earth.
• They can survive in extreme environments, such as boiling pools of water, volcanic vents, salt flats, and saltwater.
• Some microorganisms require oxygen to grow, while others do not.
• The "toughest" microorganism is Deinococcus radiodurans, which can withstand radiation, survive without water, and resist strong acids and vacuum conditions.

Classification of Microorganisms

• Microorganisms can be classified based on whether they have cells or not, and if so, how many cells they have.
• Multicellular microorganisms have more than one cell.
• Unicellular microorganisms have a single cell.
• Acellular microorganisms, such as viruses and prions, lack cells.
• Microorganisms can also be classified based on the type of cell: eukaryotes have complex cells with a true nucleus and membrane-bound organelles, while prokaryotes have simple cells without a true nucleus and lack membrane-bound organelles.

Types of Microorganisms

• Parasites are microorganisms that can be frightening, especially when they can be viewed with the naked eye.
• Examples of parasitic infections include malaria, giardia, and African sleeping sickness.
• Fungi are microorganisms that are similar to plants, including yeasts, mushrooms, and molds.
• Good fungi live on our bodies and do not cause disease.
• Bacteria are microorganisms that are abundant in and on our bodies, with most being "good bacteria" that protect us against infection and aid in digestion.
• Examples of infections caused by bacteria include tuberculosis and strep throat.
• Viruses are abundant in nature and can infect other microorganisms, including bacteria, and plants.
• Immunizations have decreased the risk of some diseases, but others, such as Ebola and Zika, remain a threat.
• Prions are infectious proteins that are not classified as microorganisms but can cause diseases such as mad cow disease and kuru.