Cheperas

Microorganism

A microorganism (from the Greek: μικρός,micros, "small" and ὀργανισμός, organisms, "organism"; also spelt micro-organism, micro organism or microörganism) or microbe is an organism that is unicellular or lives in a colony of cellular organisms.The study of microorganisms is called microbiology, a subject that began with Anton van Leeuwenhoek's discovery of microorganisms in 1675, using a microscope of his own design.
Microorganisms are verydiverse; they include bacteria, fungi, archaea, and protests; microscopic plants (green algae); and animals such as plankton and the planarian. Some microbiologists also include viruses, but othersconsider these as non-living.[1][2] Most microorganisms are unicellular (single-celled), but this is not universal, since some multicellular organisms are microscopic, while some unicellular protestsand bacteria, like Thiomargarita namibiensis, are macroscopic and visible to the naked eye.[3]
Microorganisms live in all parts of the biosphere where there is liquid water, including soil, hotsprings, on the ocean floor, high in the atmosphere and deep inside rocks within the Earth's crust. Microorganisms are critical to nutrient recycling in ecosystems as they act as decomposers. As somemicroorganisms can fix nitrogen, they are a vital part of the nitrogen cycle, and recent studies indicate that airborne microbes may play a role in precipitation and weather.[4]
Microbes are also exploitedby people in biotechnology, both in traditional food and beverage preparation, and in modern technologies based on genetic engineering. However, pathogenic microbes are harmful, since they invade andgrow within other organisms, causing diseases that kill people, other animals and plants.[5]
Bacteria
Staphylococcus aurous bacteria magnified about 10,000 xs
Bacteria are practically all...