Microbes are microscopic life forms, usually too small to be seen by the naked eye. Although many microbes are single-celled, there are also numerous multi-cellular organisms.
Microorganisms are very diverse and include bacteria, fungi, and algae. Microorganisms live in all parts on the earth where there is liquid water, including hot springs, on the ocean floor, high in the atmosphere and deep inside rocks within the Earth’s crust. Certain microbes have adapted to withstand unusual environmental conditions, including extreme pressure, temperature, acidity, and radiation. These microscopic organisms are found in plants and animals as well as in the human body. Wherever we are, we have the company of microbes.