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Microbial Ecology
Microbial ecology (or environmental microbiology) is the ecology of microorganisms: their relationship with one another and with their environment. It concerns the three major domains of life—Eukaryota, Archaea, and Bacteria—as well as viruses. Microorganisms, by their omnipresence, impact the entire biosphere. Microbial life plays a primary role in regulating biogeochemical systems in virtually all of our planet's environments, including some of the most extreme, from frozen environments and acidic lakes, to hydrothermal vents at the bottom of deepest oceans, and some of the most familiar, such as the human small intestine. As a consequence of the quantitative magnitude of microbial life (calculated as cells; eight orders of magnitude greater than the number of stars in the observable universe) microbes, by virtue of their biomass alone, constitute a significant carbon sink. Aside from carbon fixation, microorganisms' key collective metabolic processes (including nitro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanogenesis
Methanogenesis or biomethanation is the formation of methane coupled to energy conservation by microbes known as methanogens. Organisms capable of producing methane for energy conservation have been identified only from the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with anaerobic bacteria. Other forms of methane production that are not coupled to ATP synthesis exist within all three domains of life. The production of methane is an important and widespread form of microbial metabolism. In anoxic environments, it is the final step in the decomposition of biomass. Methanogenesis is responsible for significant amounts of natural gas accumulations, the remainder being thermogenic. Biochemistry Methanogenesis in microbes is a form of anaerobic respiration. Methanogens do not use oxygen to respire; in fact, oxygen inhibits the growth of methanogens. The terminal electron acceptor in methanogenesis is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Hungate
Robert Edward Hungate (1906-2004) was a pioneering microbial ecologist who developed the first techniques for the culturing of anaerobic microbes in his study of the bovine rumen. Early life Hungate was born on March 2, 1906 in Cheney, WA, where his father taught biology at the State Normal School at Cheney (now Eastern Washington University) for 46 years. Hungate's father was strongly influenced by his brother-in-law, Charles Piper, and encouraged Hungate's interest in the ecology of Eastern Washington through outings in the local area. Hungate graduated from Cheney Normal in 1924, and served as principal of the Spokane Indian Reservation's elementary school for a year, followed by another two years teaching in Sprague, Washington. He entered Stanford University with the goal of teaching biology at the high school level, but abandoned his plan after his first quarter at Stanford due to his dislike of pedagogy courses and his fellow education students, and instead completed an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil, moisture, range of temperature, and light intensity. Biotic factors will include the availability of food and the presence or absence of predators. Every species has particular habitat requirements, with habitat generalist species able to thrive in a wide array of environmental conditions while habitat specialist species requiring a very limited set of factors to survive. The habitat of a species is not necessarily found in a geographical area, it can be the interior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winogradsky Column
The Winogradsky column is a simple device for culturing a large diversity of microorganisms. Invented in the 1880s by Sergei Winogradsky, the device is a column of pond mud and water mixed with a carbon source such as newspaper (containing cellulose), blackened marshmallows or egg-shells (containing calcium carbonate), and a sulfur source such as gypsum (calcium sulfate) or egg yolk. Incubating the column in sunlight for months results in an Wikt:aerobic, aerobic/Hypoxia (environmental), anaerobic gradient as well as a sulfide gradient. These two gradients promote the growth of different microorganisms such as ''Clostridium'', ''Desulfovibrio'', ''Chlorobium'', ''Chromatium'', ''Rhodomicrobium'', and ''Beggiatoa'', as well as many other species of bacteria, cyanobacteria, and algae. The column provides numerous gradients, depending on additive nutrients, from which the variety of aforementioned organisms can grow. The aerobic water phase and anaerobic mud or soil phase are one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemosynthesis
In biochemistry, chemosynthesis is the biological conversion of one or more carbon-containing molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic compounds (e.g., hydrogen gas, hydrogen sulfide) or ferrous ions as a source of energy, rather than sunlight, as in photosynthesis. Chemoautotrophs, organisms that obtain carbon from carbon dioxide through chemosynthesis, are phylogenetically diverse. Groups that include conspicuous or biogeochemically-important taxa include the sulfur-oxidizing Gammaproteobacteria, the Campylobacterota, the Aquificota, the methanogenic archaea, and the neutrophilic iron-oxidizing bacteria. Many microorganisms in dark regions of the oceans use chemosynthesis to produce biomass from single-carbon molecules. Two categories can be distinguished. In the rare sites where hydrogen molecules (H2) are available, the energy available from the reaction between CO2 and H2 (leading to production of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microorganisms
A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in older texts. The informal synonym ''microbe'' () comes from μικρός, mikrós, "small" and βίος, bíos, "life". is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from ancient times, such as in Jain scriptures from sixth century BC India. The scientific study of microorganisms began with their observation under the microscope in the 1670s by Anton van Leeuwenhoek. In the 1850s, Louis Pasteur found that microorganisms caused food spoilage, debunking the theory of spontaneous generation. In the 1880s, Robert Koch discovered that microorganisms caused the diseases tuberculosis, cholera, diphtheria, and anthrax. Because micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sergei Winogradsky
Sergei Nikolaievich Winogradsky (or Vinohradsky; published under the name of Sergius Winogradsky or M. S. Winogradsky from Ukrainian Mykolayovych Serhiy; uk, Сергій Миколайович Виноградський; 1 September 1856 – 25 February 1953) was a Ukrainian microbiologist, ecologist and soil scientist who pioneered the cycle-of-life concept. Winogradsky discovered the first known form of lithotrophy during his research with '' Beggiatoa'' in 1887. He reported that ''Beggiatoa'' oxidized hydrogen sulfide (H2S) as an energy source and formed intracellular sulfur droplets. This research provided the first example of lithotrophy, but not autotrophy. His research on nitrifying bacteria would report the first known form of chemoautotrophy, showing how a lithotroph fixes carbon dioxide (CO2) to make organic compounds. He is best known in school science as the inventor of the Winogradsky Column technique for the study of sediment microbes. Biography Winograds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lourens Baas Becking
Lourens Gerhard Marinus Baas Becking (4 January 1895 in Deventer – 6 January 1963 in Canberra, Australia) was a Dutch botanist and microbiologist. He is known for the Baas Becking hypothesis, which he originally formulated as ''"Everything is everywhere, but the environment selects"''. Biography Baas Becking was born in Deventer on 4 January 1895. Baas Becking studied microbiology at Delft University before studying biology at Utrecht University with a focus on botany. de Wit and Bouvier (2006) p. 756 In between completing his studies in Utrecht and submitting his thesis, Baas Becking worked in the laboratory of Thomas Hunt Morgan in the United States. In 1923, Baas Becking accepted the position of professor at Stanford, where he taught economic botany and plant physiology. Baas Becking's studies at Stanford heavily influenced his later work by introducing him to research on extremophiles, research he conducted himself as the director of the Jacques Loeb Marine Laboratory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbial Biogeography
Microbial biogeography is a subset of biogeography, a field that concerns the distribution of organisms across space and time. Although biogeography traditionally focused on plants and larger animals, recent studies have broadened this field to include distribution patterns of microorganisms. This extension of biogeography to smaller scales—known as "microbial biogeography"—is enabled by ongoing advances in genetic technologies. The aim of microbial biogeography is to reveal where microorganisms live, at what abundance, and why. Microbial biogeography can therefore provide insight into the underlying mechanisms that generate and hinder biodiversity. Microbial biogeography also enables predictions of where certain organisms can survive and how they respond to changing environments, making it applicable to several other fields such as climate change research. History Schewiakoff (1893) theorized about the cosmopolitan habitat of free-living protozoans. In 1934, Lourens Baas Beck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbe
A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in older texts. The informal synonym ''microbe'' () comes from μικρός, mikrós, "small" and βίος, bíos, "life". is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from ancient times, such as in Jain scriptures from sixth century BC India. The scientific study of microorganisms began with their observation under the microscope in the 1670s by Anton van Leeuwenhoek. In the 1850s, Louis Pasteur found that microorganisms caused food spoilage, debunking the theory of spontaneous generation. In the 1880s, Robert Koch discovered that microorganisms caused the diseases tuberculosis, cholera, diphtheria, and anthrax. Because mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enrichment Culture
Enrichment culture is the use of certain growth media to favor the growth of a particular microorganism over others, enriching a sample for the microorganism of interest. This is generally done by introducing nutrients or environmental conditions that only allow the growth of an organism of interest. Enrichment cultures are used to increase a small number of desired organisms to detectable levels. This allows for the detection and identification of microorganisms with a variety of nutritional needs. Enrichment cultures are often used for soil and fecal samples. History The microbiologist (and botanist) Martinus Beijerinck is credited with developing the first enrichment cultures. Sergei Winogradsky also experimented on bacteria using different cultures. Examples Media with a high salt concentration will select for halophiles. Selenite broth is used to selectively isolate Salmonella species. Alkaline Peptone Water is used for the cultivation of vibrio. Both these examples are clin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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