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Treponema Succinifaciens
''Treponema succinifaciens'' is an anaerobic spirochete bacterium first discovered in the intestines of swine in 1981. The helical cells of ''T. succinifaciens'' grow to 16 μm in length and often form chains of cells when cultured. ''T. succinifaciens'' is gram-negative and non spore-forming. In humans ''Treponema succinifaciens'' is found in the gut microbiome of some human populations, but is not found in humans living in urban areas. The bacterium has been found in many rural and traditional human populations such as foragers from the Congo, Bedouins, Amazonians, and Tuaregs. This is likely due to increased antibiotic use in urban populations, as well as cross-contamination from animals in rural and traditional populations. Genome The genome of ''T. succinifaciens'' is 2,897,425 base pairs in length. The bacterium contains 2,723 protein-coding as well as 63 RNA genes. It also contains 63 genes that are involved in motility Motility is the ability of an organism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic Organisms
An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenated environment. Anaerobes may be unicellular (e.g. protozoans, bacteria) or multicellular. Most fungi are obligate aerobes, requiring oxygen to survive. However, some species, such as the Chytridiomycota that reside in the rumen of cattle, are obligate anaerobes; for these species, anaerobic respiration is used because oxygen will disrupt their metabolism or kill them. Deep waters of the ocean are a common anoxic environment. First observation In his letter of 14 June 1680 to The Royal Society, Antonie van Leeuwenhoek described an experiment he carried out by filling two identical glass tubes about halfway with crushed pepper powder, to which some clean rain water was added. Van Leeuwenhoek sealed one of the glass tubes using a flame an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterium
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 relationshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helix
A helix () is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helices, and many proteins have helical substructures, known as alpha helices. The word ''helix'' comes from the Greek word ''ἕλιξ'', "twisted, curved". A "filled-in" helix – for example, a "spiral" (helical) ramp – is a surface called ''helicoid''. Properties and types The ''pitch'' of a helix is the height of one complete helix turn, measured parallel to the axis of the helix. A double helix consists of two (typically congruent) helices with the same axis, differing by a translation along the axis. A circular helix (i.e. one with constant radius) has constant band curvature and constant torsion. A ''conic helix'', also known as a ''conic spiral'', may be defined as a spiral on a conic surface, with the distance to the apex an expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are found in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism ''Escherichia coli'', as well as many pathogenic bacteria, such as ''Pseudomonas aeruginosa'', ''Chlamydia trachomatis'', and ''Yersinia pestis''. They are a significant medical challenge as their outer membrane protects them from many antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gut Microbiome
Gut microbiota, gut microbiome, or gut flora, are the microorganisms, including bacteria, archaea, fungi, and viruses that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the gut microbiota. The gut is the main location of the human microbiome. The gut microbiota has broad impacts, including effects on colonization, resistance to pathogens, maintaining the intestinal epithelium, metabolizing dietary and pharmaceutical compounds, controlling immune function, and even behavior through the gut–brain axis. The microbial composition of the gut microbiota varies across regions of the digestive tract. The colon contains the highest microbial density recorded in any habitat on Earth, representing between 300 and 1000 different species. Bacteria are the largest and to date, best studied component and 99% of gut bacteria come from about 30 or 40 species. Up to 60% of the dry mass of feces is bacteria. Over 99% of the bacter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Pygmies
The African Pygmies (or Congo Pygmies, variously also Central African foragers, "African rainforest hunter-gatherers" (RHG) or "Forest People of Central Africa") are a group of ethnicities native to Central Africa, mostly the Congo Basin, traditionally subsisting on a forager and hunter-gatherer lifestyle. They are divided into three roughly geographic groups: *the western ''Bambenga'', or ''Mbenga'' (Cameroon, Gabon, Republic of the Congo, Central African Republic), *the eastern ''Bambuti'', or ''Mbuti'', of the Congo basin (DRC) *the central and southern ''Batwa'', or ''Twa'' (Rwanda, Burundi, DRC, Tanzania, Uganda, Zambia, Angola and Namibia). The more widely scattered (and more variable in physiology and lifestyle) Southern Twa are also grouped under the term Pygmoid. They are notable for, and named for, their short stature (described as "pygmyism" in anthropological literature). They are assumed to be descended from the original Middle Stone Age expansion of anatomically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bedouins
The Bedouin, Beduin, or Bedu (; , singular ) are nomadic Arabs, Arab tribes who have historically inhabited the desert regions in the Arabian Peninsula, North Africa, the Levant, and Mesopotamia. The Bedouin originated in the Syrian Desert and Arabian Desert but spread across the rest of the Arab world in Western Asia, West Asia and North Africa after the spread of Islam. The English word ''bedouin'' comes from the Arabic ''badawī'', which means "desert dweller", and is traditionally contrasted with ''ḥāḍir'', the term for Sedentism, sedentary people. Bedouin territory stretches from the vast deserts of North Africa to the rocky sands of the Middle East. They are traditionally divided into tribes, or clans (known in Arabic as ''ʿašāʾir''; or ''qabāʾil'' ), and historically share a common culture of herding camels and goats. The vast majority of Bedouins adhere to Islam, although there are some fewer numbers of Arab Christians, Christian Bedouins present in the Fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indigenous Peoples In Brazil
Indigenous peoples in Brazil ( pt, povos indígenas no Brasil) or Indigenous Brazilians ( pt, indígenas brasileiros, links=no) once comprised an estimated 2000 tribes and nations inhabiting what is now the country of Brazil, before European contact around 1500. Christopher Columbus thought he had reached the East Indies, but Portuguese Vasco da Gama had already reached India via the Indian Ocean route, when Brazil was colonized by Portugal. Nevertheless, the word ("Indians") was by then established to designate the people of the New World and continues to be used in the Portuguese language to designate these people, while a person from India is called in order to distinguish the two. At the time of European contact, some of the Indigenous people were traditionally semi-nomadic tribes who subsisted on hunting, fishing, gathering and migrant agriculture. Many tribes suffered extinction as a consequence of the European settlement and many were assimilated into the Brazilian po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuaregs
The Tuareg people (; also spelled Twareg or Touareg; endonym: ''Imuhaɣ/Imušaɣ/Imašeɣăn/Imajeɣăn'') are a large Berber ethnic group that principally inhabit the Sahara in a vast area stretching from far southwestern Libya to southern Algeria, Niger, Mali, and Burkina Faso. Traditionally nomadic pastoralists, small groups of Tuareg are also found in northern Nigeria. The Tuareg speak languages of the same name (also known as ''Tamasheq''), which belong to the Berber branch of the Afroasiatic family. The Tuaregs have been called the "blue people" for the indigo dye coloured clothes they traditionally wear and which stains their skin. They are a semi-nomadic people who practice Islam, and are descended from the indigenous Berber communities of Northern Africa, which have been described as a mosaic of local Northern African (Taforalt), Middle Eastern, European (Early European Farmers), and Sub-Saharan African-related ancestries, prior to the Arab expansion. Tuareg people ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Pairs
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA and RNA. Dictated by specific hydrogen bonding patterns, "Watson–Crick" (or "Watson–Crick–Franklin") base pairs (guanine–cytosine and adenine–thymine) allow the DNA helix to maintain a regular helical structure that is subtly dependent on its nucleotide sequence. The complementary nature of this based-paired structure provides a redundant copy of the genetic information encoded within each strand of DNA. The regular structure and data redundancy provided by the DNA double helix make DNA well suited to the storage of genetic information, while base-pairing between DNA and incoming nucleotides provides the mechanism through which DNA polymerase replicates DNA and RNA polymerase transcribes DNA into RNA. Many DNA-binding proteins ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein-coding Genes
The human genome is a complete set of nucleic acid sequences for humans, encoded as DNA within the 23 chromosome pairs in cell nuclei and in a small DNA molecule found within individual Mitochondrial DNA, mitochondria. These are usually treated separately as the nuclear genome and the Human mitochondrial genetics, mitochondrial genome. Human genomes include both protein-coding DNA sequences and various types of non-coding DNA, DNA that does not encode proteins. The latter is a diverse category that includes DNA coding for non-translated RNA, such as that for ribosomal RNA, transfer RNA, ribozymes, small nuclear RNAs, and several types of RNA#Regulatory RNA, regulatory RNAs. It also includes Promoter (biology), promoters and their associated Cis-regulatory element, gene-regulatory elements, DNA playing structural and replicatory roles, such as Scaffold/matrix attachment region, scaffolding regions, telomeres, centromeres, and Origin of replication, origins of replication, plus large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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