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GFAJ-1
GFAJ-1 is a strain of rod-shaped bacteria in the family Halomonadaceae. It is an extremophile that was isolated from the hypersaline and alkaline Mono Lake in eastern California by geobiologist Felisa Wolfe-Simon, a NASA research fellow in residence at the US Geological Survey. In a 2010 ''Science'' journal publication, the authors claimed that the microbe, when starved of phosphorus, is capable of substituting arsenic for a small percentage of its phosphorus to sustain its growth. Immediately after publication, other microbiologists and biochemists expressed doubt about this claim, which was robustly criticized in the scientific community. Subsequent independent studies published in 2012 found no detectable arsenate in the DNA of GFAJ-1, refuted the claim, and demonstrated that GFAJ-1 is simply an arsenate-resistant, phosphate-dependent organism. Discovery The GFAJ-1 bacterium was discovered by geomicrobiologist Felisa Wolfe-Simon, a NASA astrobiology fellow in residence at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felisa Wolfe-Simon
Felisa Wolfe-Simon is an American microbial geobiologist and biogeochemist. In 2010, Wolfe-Simon led a team that discovered GFAJ-1, an extremophile bacterium that they claimed was capable of substituting arsenic for a small percentage of its phosphorus to sustain its growth, thus advancing the remarkable possibility of non-RNA/DNA-based genetics. However, these conclusions were immediately debated and criticized in correspondence to the original journal of publication, and have since come to be widely disbelieved. In 2012, two reports refuting the most significant aspects of the original results were published in the same journal in which the original findings had been previously published. Education and career Wolfe-Simon did her undergraduate studies at Oberlin College and completed a Bachelor of Arts in Biology and Chemistry and a Bachelor of Music in Oboe Performance and Ethnomusicology at the Oberlin Conservatory of Music. She received her Doctor of Philosophy in oceanog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halomonadaceae
Halomonadaceae is a family of halophilic Pseudomonadota. History The family was originally described in 1988 to contain the genera ''Halomonas'' and ''Deleya''. In 1989, ''Chromobacterium marismortui'' was reclassified as ''Chromohalobacter marismortui'' forming a third genus in the family Halomonadaceae. Subsequently, in 1990 a species was discovered and was originally proposed to be called ''Volcaniella eurihalina'' forming a new genus in the ''Halomonadaceae'', but was later (in 1995) reclassified as a member of the genus ''Halomonas''. The species ''Carnimonas nigrificans'' (sole member of genus) was not placed in the family due to the lack of two out of 15 descriptive 16S rRNA signature sequences, but it has been proposed to reclassify it into the family. In 1996, the family was later reorganised by unifying genera ''Deleya'', ''Halomonas'' and ''Halovibrio'' and the species ''Paracoccus halodenitrificans'' into ''Halomonas'' and placing ''Zymobacter'' in this family. Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extremophile
An extremophile (from Latin ' meaning "extreme" and Greek ' () meaning "love") is an organism that is able to live (or in some cases thrive) in extreme environments, i.e. environments that make survival challenging such as due to extreme temperature, radiation, salinity, or pH level. These organisms are ecologically dominant in the evolutionary history of the planet. Some spores and cocooned bacteria samples have been dormant for more than 40 million years, extremophiles have continued to thrive in the most extreme conditions, making them one of the most abundant lifeforms. Characteristics In the 1980s and 1990s, biologists found that microbial life has great flexibility for surviving in extreme environments—niches that are acidic, extraordinarily hot or within irregular air pressure for example—that would be completely inhospitable to complex organisms. Some scientists even concluded that life may have begun on Earth in hydrothermal vents far under the ocean's surfa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry. The primary use of arsenic is in alloys of lead (for example, in car batteries and ammunition). Arsenic is a common n-type dopant in semiconductor electronic devices. It is also a component of the III-V compound semiconductor gallium arsenide. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, and insecticides. These applications are declining with the increasing recognition of the toxicity of arsenic and its compounds. A few species of bacteria are able to use arsenic compounds as respiratory metabolites. Trace quantities of arsenic are an essential dietary element in rats, ham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mono Lake
Mono Lake ( ) is a saline soda lake in Mono County, California, formed at least 760,000 years ago as a terminal lake in an endorheic basin. The lack of an outlet causes high levels of salts to accumulate in the lake which make its water alkaline. The desert lake has an unusually productive ecosystem based on brine shrimp, which thrive in its waters, and provides critical habitat for two million annual migratory birds that feed on the shrimp and alkali flies ('' Ephydra hians''). Historically, the native Kutzadika'a people ate the alkali flies' pupae, which live in the shallow waters around the edge of the lake. When the city of Los Angeles diverted water from the freshwater streams flowing into the lake, it lowered the lake level, which imperiled the migratory birds. The Mono Lake Committee formed in response and won a legal battle that forced Los Angeles to partially replenish the lake level. Geology Mono Lake occupies part of the Mono Basin, an endorheic basin that has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanospirillales
The Oceanospirillales are an order of Pseudomonadota with ten families. Description Bacteria in the ''Oceanospirillales'' are metabolically and morphologically diverse, with some able to grow in the presence of oxygen and others requiring an anaerobic environment. Members of the ''Oceanospirillales'' can be halotolerant or halophilic and require high salt concentrations to grow. While they grow in diverse niches, all ''Oceanospirillales'' derive their energy from the breakdown of various organic products. Bacteria in the ''Oceanospirillales'' are motile except for those in the genus ''Alcanivorax''. Bacteria in the ''Oceanospirillales'' include hydrocarbon-degrading groups such as ''Oleispira antarctica'', ''Thalassolituus oleivorans'', and ''Oleiphilus messinensis'' , which were found in the indigenous microbial community in deep waters after the Deepwater Horizon oil spill in 2010. They are also common members of bacterial communities in the water column of the hadal The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
503354main Wolfe Simon
5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number. It has attained significance throughout history in part because typical humans have five digits on each hand. In mathematics 5 is the third smallest prime number, and the second super-prime. It is the first safe prime, the first good prime, the first balanced prime, and the first of three known Wilson primes. Five is the second Fermat prime and the third Mersenne prime exponent, as well as the third Catalan number, and the third Sophie Germain prime. Notably, 5 is equal to the sum of the ''only'' consecutive primes, 2 + 3, and is the only number that is part of more than one pair of twin primes, ( 3, 5) and (5, 7). It is also a sexy prime with the fifth prime number and first prime repunit, 11. Five is the third factorial prime, an alternating factorial, and an Eisenstein prime with no imaginary part and real part of the form 3p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geomicrobiology
Geomicrobiology is the scientific field at the intersection of geology and microbiology and is a major subfield of geobiology. It concerns the role of microbes on geological and geochemical processes and effects of minerals and metals to microbial growth, activity and survival. Such interactions occur in the geosphere (rocks, minerals, soils, and sediments), the atmosphere and the hydrosphere. Geomicrobiology studies microorganisms that are driving the Earth's biogeochemical cycles, mediating mineral precipitation and dissolution, and sorbing and concentrating metals. The applications include for example bioremediation, mining, climate change mitigation and public drinking water supplies. Rocks and minerals Microbe-aquifer interactions Microorganisms are known to impact aquifers by modifying their rates of dissolution. In the karstic Edwards Aquifer, microbes colonizing the aquifer surfaces enhance the dissolution rates of the host rock. In the oceanic crustal aquifer, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Astrobiology Institute
The NASA Astrobiology Institute (NAI) was established in 1998 by the National Aeronautics and Space Administration (NASA) "to develop the field of astrobiology and provide a scientific framework for flight missions." In December 2019 the institute's activities were suspended. The NAI is a virtual, distributed organization that integrates astrobiology research and training programs in concert with the national and international science communities. History Although NASA had explored the idea of forming an astrobiology institute in the past, when the Viking biological experiments returned negative results for life on Mars, the public lost interest and federal funds for exobiology dried up. In 1996, the announcement of possible traces of ancient life in the Allan Hills 84001 meteorite from Mars led to new interest in the subject. At the same time, NASA developed the Origins Program, broadening its reach from exobiology to ''astrobiology'', the study of the origin, evolution, dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrobiology
Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investigates the deterministic conditions and contingent events with which life arises, distributes, and evolves in the universe. Astrobiology makes use of molecular biology, biophysics, biochemistry, chemistry, astronomy, physical cosmology, exoplanetology, geology, paleontology, and ichnology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from that on Earth. The origin and early evolution of life is an inseparable part of the discipline of astrobiology. Astrobiology concerns itself with interpretation of existing scientific data, and although speculation is entertained to give context, astrobiology concerns itself primarily with hypotheses that fit firmly into existing scientific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wall Street Journal
''The Wall Street Journal'' is an American business-focused, international daily newspaper based in New York City, with international editions also available in Chinese and Japanese. The ''Journal'', along with its Asian editions, is published six days a week by Dow Jones & Company, a division of News Corp. The newspaper is published in the broadsheet format and online. The ''Journal'' has been printed continuously since its inception on July 8, 1889, by Charles Dow, Edward Jones, and Charles Bergstresser. The ''Journal'' is regarded as a newspaper of record, particularly in terms of business and financial news. The newspaper has won 38 Pulitzer Prizes, the most recent in 2019. ''The Wall Street Journal'' is one of the largest newspapers in the United States by circulation, with a circulation of about 2.834million copies (including nearly 1,829,000 digital sales) compared with ''USA Today''s 1.7million. The ''Journal'' publishes the luxury news and lifestyle magazine ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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