Alkaliphiles are of two types; obligate alkaliphiles growing only in environments with pH higher than 9 and facultative alkaliphiles that can live both at neutral pH and alkaline conditions. Anopheles mosquitoes are the principal vectors of the parasites that cause malaria in Africa, where in 2018, 93% of the world's estimated 228 million cases and 94% of its 405,000 malaria deaths occurred ([ 1 ][1]). Xerophiles are closely related to halophiles as halophilic environments tend to have low water activity. There are several natural acidic environments that include volcanic areas, hydrothermal sources, deep-sea vents, metal mining areas, and the stomachs of animals. Halophilic enzymes are more stable than their non-halophilic counterparts owing to their polyextremophilic characteristics. Yoder. An extreme environment is a habitat characterized by harsh environmental conditions further than the optimal range for the development of humans or other living organisms. Cold and hot deserts are some examples of these extreme environments. Another successful modification is the incorporation of very-long-chain dicarboxylic fatty acids which make up more than 50% of the membrane fatty acid. A thermostable glucokinase from the thermophilic species. Polluted soils and waters with untreated industrial and urban wastes and samples of the natural environment with a high concentration of metals are important habitats of metallotolerant microorganisms. Before the cell enters G1 phase, i.e. Most hyperthermophilic organisms are found in hot springs and boiling steam vents where even moderate thermophiles cannot survive or thrive. Alkaliphiles can be isolated from ‘normal’ environments such as garden soil presumably because there are transient alkaline conditions generated in such environments by biological activity. Endoliths occupy habitats beneath and between porous and translucent rocks and minerals. Musilova M, Wright G, Ward JM, Dartnell LR. Centrioles, basal bodies, and cilia are important for mitosis, polarity, cell division, protein trafficking, signaling, motility and sensation. A high-salt environment substantially impacts protein solubility and stability and consequently, its function. Extremely cold environments are those with environmental temperatures below 5°C. Springer, Berlin, Heidelberg. Psychrophiles have successfully overcome two main challenges that arise during growth at low temperature: first, low temperature, because any decrease in temperature exponentially affects the rate of biochemical reactions; and second, the viscosity of aqueous environments. Psychrophiles, literally meaning cold-loving, are organisms adapted to growth at low temperatures, having an optimum growth temperature of greater than 15°C and a maximum growth temperature of greater than 20°C. Hyperthermophiles are organisms that can survive and grow at extremely high temperatures (above 80°C). The formation of spores and reduction in metabolic activities provide long periods of survival for many microorganisms as well as larger eukaryotes. Some extremophilic microorganisms may also comprise a large reservoir of novel therapeutic agents—for example, iron-binding antifungal compound, pyochelin isolated from halophilic species of. Similarly, many barophiles tend to be obligate barophiles with few archaea acting as moderately barophilic. Weleber, G. Inana. This is a list of dates associated with the prehistoric peopling of the world (first known presence of Homo sapiens).. In addition to extremes of cold, many psychrophiles tolerate or in some cases require other extreme environmental conditions for growth and survival. The list is divided into four categories, Middle Paleolithic (before 50,000 years ago), Upper Paleolithic (50,000 to 12,500 years ago), Holocene (12,500 to 500 years ago) and Modern (Age of Sail and modern exploration). In acidophilic archaea, there is a strong association between the presence of tetraether lipids in the cell membrane and tolerance to acid pH. S.J. As the weathering process continues, the organic matter of the area increases so that new groups of living microorganisms can thrive at such a climate. Xerophilic cyanobacteria code for various shock response genes on dehydration that regulate the utilization of water in metabolic processes during desiccation. Mirete, S., Morgante, V., & González-Pastor, J. E. (2017). There are many examples of the environment with extreme temperatures. Alkaline active proteases, amylases, cellulases, mannanases, lipases, etc. Edbeib, M. F., Wahab, R. A., & Huyop, F. (2016). Winyard, S. Malcolm, A.S. Woolf, S.A.Feather. Studies on radiophiles are quite limited as they are to be isolated from extreme environments like outer space of other planets. A basal body (synonymous with basal granule, kinetosome, and in older cytological literature with blepharoplast) is a protein structure found at the base of a eukaryotic undulipodium (cilium or flagellum). Chaperons are known to be involved in refolding proteins that are unfolded by stresses, thus increasing the tolerance levels. The basal body differs from the mother centriole in at least 2 aspects. Thermophiles contain special DNA binding proteins that arrange the DNA into globular particles that are more resistant to melting. X. Shu, A.M. Fry, B. Tulloch, J.W. Some common examples of barophilic microorganisms are. They are physiologically diverse; mostly aerobic and as well anaerobic, heterotrophic, phototrophic, and chemoautotrophic. Various xerophilic organisms form biofilms as it allows the survival of organisms in habitats with low moisture content. Alkaliphiles produce metabolic acid through sugar fermentation and amino acid deaminases. For an area to be considered extreme, certain conditions or aspects of the environment must be considered very hard for different forms of life to survive.