What is a microorganism?

An organism of microscopic size. Microorganisms also include organisms of sizes that are undetectable through a microscope, that is, of submicroscopic size. Microorganisms are a basic component of life. They exist everywhere: in the ground, in the water, in the air, on surfaces, on our body, in our body, in our intestines, and so forth. They are the cause of decomposition, putrefaction, foul order, or the cause of fermentation, natural preservation (pickling), sweet-sour smell; they are the cause of disease or maintains health; they are a part of digestion; they give us colds; yet they give us beer, cheese, bread, yogurt (the old fashion kind); they give us pickles, saurkraut, soy sauce, kim-chee (Korean pickled cabbage); and they give us the ability to cycle life sustainably at the human level -- treat waste and turn them into useful resources.  more