A microorganism (also spelled micro organism or micro-organism and also called a microbe) is an organism that is microscopic (usually too small to be seen by the naked human eye). 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 incredibly diverse and include bacteria, fungi, archaea, and protists, as well as some microscopic pla
nts and animals such as plankton.Many scientists would not include viruses and prions, which are often classified as non-living. Most microorganisms are single-celled, or unicellular, but some multicellular organisms are microscopic, while some unicellular protists, and bacteria called Thiomargarita namibiensis are visible to the naked eye.
Microorganisms live in all parts of the biosphere 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. Microorganisms are critical to nutrient recycling in ecosystems as they act as decomposers. As some microorganisms 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.
Microbes are also exploited by 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 and grow within other organisms, causing diseases that kill millions of people, other animals, and plants.
Microbiology-- is the study of microorganisms, which are unicellular or cell-cluster microscopic organisms.
Bacteria-- (pl.bacterium) are a group of unicellular microorganisms.
Archaea-- are a group of single-celled microorganisms. Archaea, like bacteria, are prokaryotes and have no cell nucleus or any other organelles within their cells.
Plankton --consist of any drifting organisms (animals, plants, archaea, or bacteria) that inhabit the of oceans, seas, or bodies of fresh water. Plankton provide a crucial source of food to aquatic life.
Prion-- an infectious protein particle similar to a virus but lacking nucleic acid; thought to be the agent responsible for scrapie and other degenerative diseases of the nervous system .
Thiomargarita namibiensis -- is a gram-negative coccus Proteobacterium found in the ocean sediments of the continental shelf. Discovered in 1999, it is the largest bacterium ever discovered, with a width up to 750 μm (0.75 mm), making it easily visible to the naked eye.
Nitrogen fixation-- is the process by which nitrogen is taken from its natural, relatively inert molecular form (N2) in the atmosphere and converted into nitrogen compounds
biosphere-- is the part of the Earth, including air, land, surface rocks, and water, within which life occurs, and which biotic processes in turn alter or transform.
Decomposers-- are organisms that consume dead organisms, and, in doing so, carry out the natural process of decomposition.
Microorganisms are incredibly diverse and include bacteria, fungi, archaea, and protists, as well as some microscopic pla
nts and animals such as plankton.Many scientists would not include viruses and prions, which are often classified as non-living. Most microorganisms are single-celled, or unicellular, but some multicellular organisms are microscopic, while some unicellular protists, and bacteria called Thiomargarita namibiensis are visible to the naked eye.Microorganisms live in all parts of the biosphere 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. Microorganisms are critical to nutrient recycling in ecosystems as they act as decomposers. As some microorganisms 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.
Microbes are also exploited by 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 and grow within other organisms, causing diseases that kill millions of people, other animals, and plants.Microbiology-- is the study of microorganisms, which are unicellular or cell-cluster microscopic organisms.
Bacteria-- (pl.bacterium) are a group of unicellular microorganisms.
Archaea-- are a group of single-celled microorganisms. Archaea, like bacteria, are prokaryotes and have no cell nucleus or any other organelles within their cells.
Plankton --consist of any drifting organisms (animals, plants, archaea, or bacteria) that inhabit the of oceans, seas, or bodies of fresh water. Plankton provide a crucial source of food to aquatic life.
Prion-- an infectious protein particle similar to a virus but lacking nucleic acid; thought to be the agent responsible for scrapie and other degenerative diseases of the nervous system .
Thiomargarita namibiensis -- is a gram-negative coccus Proteobacterium found in the ocean sediments of the continental shelf. Discovered in 1999, it is the largest bacterium ever discovered, with a width up to 750 μm (0.75 mm), making it easily visible to the naked eye.
Nitrogen fixation-- is the process by which nitrogen is taken from its natural, relatively inert molecular form (N2) in the atmosphere and converted into nitrogen compounds
biosphere-- is the part of the Earth, including air, land, surface rocks, and water, within which life occurs, and which biotic processes in turn alter or transform.
Decomposers-- are organisms that consume dead organisms, and, in doing so, carry out the natural process of decomposition.
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