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Thursday 19 May 2016

Microorganism

A microorganism or microbe is an organism which is too small to be seen by the unaided human eye. The study of microorganisms is called microbiology.

Microorganisms include bacteria, fungi, archaea or protists and viruses. The first four types of microorganisms may be either free-living or parasitic. Viruses, however, always reproduce inside other living things.

Ancient Roman scholar Marcus Terentius Varro predicted microbiology over 2000 years ago, writing "there are bred certain minute creatures which cannot be seen by the eyes, but which float in the air and enter the body through the mouth and nose and cause serious diseases."

Using his handcrafted microscopes, Dutch tradesman and scientist Antonie Philips van Leeuwenhoek (October 24, 1632 – August 26, 1723) was the first to observe and describe microorganisms, which he originally referred to as animalcules (from Latin animalculum = "tiny animal").

Most of the "animalcules" are now referred to as unicellular organisms, though he observed multicellular organisms in pond water. Van Leeuwenhoek was also the first to document microscopic observations of muscle fibers, bacteria, spermatozoa, and blood flow in capillaries.

Portrait of Antonie van Leeuwenhoek (1632–1723) by Jan Verkolje

Louis Pasteur  (1822–1895) introduced the science of microbiology. His experiments with microbes involved work with rotten meat; the chemist's laboratory was often filled with putrid smells. "Public usefulness ennobles the most disgusting work," he said.

In 1876, Robert Koch (1843–1910) established that microorganisms can cause disease. He found that the blood of cattle which were infected with anthrax always had large numbers of Bacillus anthracis.

A new microbe called a hemimastigote was discovered in a Nova Scotian soil sample, and successfully cultivated in the laboratory. The Hemimastix kukwesjijk is not a plant, animal, fungus, or protozoa — it constitutes an entirely new kingdom.

In July 2020, marine biologists studying the seafloor in the South Pacific Gyre (a system of circulating ocean currents) discovered aerobic microorganisms in "quasi-suspended animation." At 101.5 million years old, they are the longest-living life forms ever found.

Methanogens are micro-organisms that are very sensitive to the presence of oxygen and prefer carbon dioxide - or other carbon-rich compounds - to produce water and methane. Methanogens are common in wetlands, where they are responsible for marsh gas, and in the digestive tracts of animals including humans. They are also found in extreme environments, such as deep-sea hydrothermal vents and in the Earth’s mantle.

Sometimes, as with herbivores, the microorganisms are vital to the digestion of food. The human gut has more organisms living inside it than there are cells in the human body.

The human gut contains more microbes than there are stars in the universe.

A cluster of Escherichia coli bacteria magnified 10,000 times

It is estimated that one teaspoon of soil holds the DNA of over 10,000 microbial species.

There are 700 species of microbes living in your mouth.

If you took all the microbes off and out of your body and put them in a bucket, they would weigh about three pounds.

There are roughly 100 times more genes in the human microbiome—the trillions of microbes living in and us—than in the human genome.

The world’s oceans contain a nonillion (1 followed by 30 zeros) microbes. Combined, they weigh the same as 240 billion African elephants.

In May 2016, scientists reported that 1 trillion species, mostly microorganisms, are estimated to be on Earth currently with only one-thousandth of one percent described.

A microscopic mite Lorryia formosa

Dark chocolate is feasted on by "good" microbes in the gut, resulting in the production of anti-inflammatory compounds.

Each of us emits a microbial cloud that is so distinctive, researchers can identify someone just by studying the air in that person’s room.

Source Daily Mail

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