A microorganism or microbe is a microscopic organism that comprises either a single cell (unicellular), cell clusters, or no cell at all (acellular). 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 very diverse; they include bacteria, fungi, archaea, and protists; microscopic plants (green algae); and animals such as plankton and the planarian. Some microbiologists also include viruses, but others consider these as non-living.Most microorganisms are unicellular (single-celled), but this is not universal, since some multicellular organisms are microscopic, while some unicellular protists and bacteria, like Thiomargarita namibiensis, are macroscopic and visible to the naked eye.
Microorganisms live in all parts of the biosphere where there is liquid water, including soil, 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 people, other animals and plants.
__Types of microorganisms
__Importance of microorganisms
-Use in food-Microorganisms are used in brewing, winemaking, baking, pickling and other food-making processes.
They are also used to control the fermentationprocess in the production of cultured dairy products such as yogurt and cheese. The cultures also provide flavour and aroma, and inhibit undesirable organisms.
-Use in water treatment-Specially-cultured microbes are used in the biological treatment of sewage and industrial waste effluent, a process known as bioaugmentation.
-Use in energy-Microbes are used in fermentation to produce ethanol,and in biogas reactors to produce methane.Scientists are researching the use of algae to produce liquid fuels,and bacteria to convert various forms of agricultural and urban waste into usable fuels.
-Use in science-Microbes are also essential tools in biotechnology, biochemistry, genetics, and molecular biology. The yeasts (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) are important model organisms in science, since they are simple eukaryotes that can be grown rapidly in large numbers and are easily manipulated.They are particularly valuable in genetics, genomics and proteomics.Microbes can be harnessed for uses such as creating steroids and treating skin diseases. Scientists are also considering using microbes for living fuel cells,and as a solution for pollution.
-Use in warfare-In the Middle Ages, diseased corpses were thrown into castles during sieges using catapults or other siege engines. Individuals near the corpses were exposed to the deadly pathogen and were likely to spread that pathogen to others.
Do you know?
The first antibotic was developed by Alexandar Flemming. He discovered that fungi produced a type of chemical called penicillin. Penicillin is used to cure diseases caused by certain bacteria.
Garlic contains a substance that has powerful antibotic and anti-fungal properties.Garlic has been used as food and medicine for many years.It is claimed to prevent heart disease,high cholesterol, hypertension,fight cold,improve immune system and also protect against cancer.