|
Xerophiles
A xerophile () is an extremophilic organism that can grow and reproduce in conditions with a low availability of water, also known as water activity. Water activity (aw) is measured as the humidity above a substance relative to the humidity above pure water (Aw = 1.0). Xerophiles are "xerotolerant", meaning tolerant of dry conditions. They can often survive in environments with water activity below 0.8; above which is typical for most life on Earth. Typically xerotolerance is used with respect to matric drying, where a substance has a low water concentration. These environments include arid desert soils. The term osmotolerance is typically applied to organisms that can grow in solutions with high solute concentrations (salts, sugars), such as halophiles. The common food preservation method of reducing water ( food drying) activities may not prevent the growth of xerophilic organisms, often resulting in food spoilage. Some mold and yeast species are xerophilic. Mold growth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerophiles
A xerophile () is an extremophilic organism that can grow and reproduce in conditions with a low availability of water, also known as water activity. Water activity (aw) is measured as the humidity above a substance relative to the humidity above pure water (Aw = 1.0). Xerophiles are "xerotolerant", meaning tolerant of dry conditions. They can often survive in environments with water activity below 0.8; above which is typical for most life on Earth. Typically xerotolerance is used with respect to matric drying, where a substance has a low water concentration. These environments include arid desert soils. The term osmotolerance is typically applied to organisms that can grow in solutions with high solute concentrations (salts, sugars), such as halophiles. The common food preservation method of reducing water ( food drying) activities may not prevent the growth of xerophilic organisms, often resulting in food spoilage. Some mold and yeast species are xerophilic. Mold growth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerophyte
A xerophyte (from Greek ξηρός ''xeros'' 'dry' + φυτόν ''phuton'' 'plant') is a species of plant that has adaptations to survive in an environment with little liquid water, such as a desert such as the Sahara or places in the Alps or the Arctic. Popular examples of xerophytes are cacti, pineapple and some Gymnosperm plants. The structural features ( morphology) and fundamental chemical processes (physiology) of xerophytes are variously adapted to conserve water, also common to store large quantities of water, during dry periods. Other species are able to survive long periods of extreme dryness or desiccation of their tissues, during which their metabolic activity may effectively shut down. Plants with such morphological and physiological adaptations are .” Xeromorphic”, The Cambridge Illustrated Glossary of Botanical Terms, Michael Hickey, Clive King, Cambridge University Press, 2001 Xerophytes such as cacti are capable of withstanding extended periods of dry condit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerocole
A xerocole (), is a general term referring to any animal that is adapted to live in a desert. The main challenges xerocoles must overcome are lack of water and excessive heat. To conserve water they avoid evaporation and concentrate excretions (i.e. urine and feces). Some are so adept at conserving water or obtaining it from food that they do not need to drink at all. To escape the desert heat, xerocoles tend to be either nocturnal or crepuscular (most active at dawn and dusk). Water conservation Avoiding evaporation Xerocoles have developed a variety of mechanisms to reduce water loss via evaporation. Mammalian xerocoles sweat much less than their non-desert counterparts. For example, the camel can survive ambient temperatures as high as without sweating, and the kangaroo rat lacks sweat glands entirely. Both birds and mammals in the desert have oils on the surface of their skin to "waterproof" it and inhibit evaporation. Desert insects use a similar method, as their cut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mold (fungus)
A mold () or mould () is one of the structures certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. Not all fungi form molds. Some fungi form mushrooms; others grow as single cells and are called microfungi (for example yeasts). A large and taxonomically diverse number of fungal species form molds. The growth of hyphae results in discoloration and a fuzzy appearance, especially on food. The network of these tubular branching hyphae, called a mycelium, is considered a single organism. The hyphae are generally transparent, so the mycelium appears like very fine, fluffy white threads over the surface. Cross-walls (septa) may delimit connected compartments along the hyphae, each containing one or multiple, genetically identical nuclei. The dusty texture of many molds is caused by profuse production of asexual spores (conidia) formed by dif ... [...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] |
Zygosaccharomyces
''Zygosaccharomyces'' is a genus of yeasts in the family Saccharomycetaceae. It was first described under the genus ''Saccharomyces'', but in 1983, it was reclassified to its current name in the work by Barnett ''et al''. The yeast has a long history as a well-known spoilage yeast within the food industry, because several species in this genus are significantly resistant to many of the common food preservation methods. For example, the biochemical properties '' Z. bailii'' possesses to achieve this includes high sugar tolerance (50-60%), high ethanol tolerance (up to 18%), high acetic acid tolerance (2.0-2.5%), very high sorbic and benzoic acid tolerance (up to 800–1000 mg/L), high molecular SO2 tolerance (greater than 3 mg/L), and high xerotolerance A xerophile () is an extremophilic organism that can grow and reproduce in conditions with a low availability of water, also known as water activity. Water activity (aw) is measured as the humidity above a substance rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biology Terminology
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions from sub-disciplines and related fields, see Glossary of genetics, Glossary of evolutionary biology, Glossary of ecology, and Glossary of scientific naming, or any of the organism-specific glossaries in :Glossaries of biology. A B C D E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cactus
A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek word (''káktos''), a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. Although some species live in quite humid environments, most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on Earth. Because of this, cacti show many adaptations to conserve water. For example, almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitute 1% of all described fungal species. Yeasts are unicellular organisms that evolved from multicellular ancestors, with some species having the ability to develop multicellular characteristics by forming strings of connected budding cells known as pseudohyphae or false hyphae. Yeast sizes vary greatly, depending on species and environment, typically measuring 3–4 µm in diameter, although some yeasts can grow to 40 µm in size. Most yeasts reproduce asexually by mitosis, and many do so by the asymmetric division process known as budding. With their single-celled growth habit, yeasts can be contrasted with molds, which grow hyphae. Fungal species that can take both forms (depending on temperature or other conditions) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichosporonoides Nigrescens
''Moniliella'' is a genus of fungi in the subdivision Ustilaginomycotina. Some species of ''Moniliella'' can cause disease in humans and in cats. The genus includes the black, yeast-like fungi in the Basidiomycota, although the black, yeast-like fungi also include some species from the Ascomycota. Species List of species: *''M. acetoabutans'' *''M. fonsecae'' *''M. madida'' (formerly in ''Trichosporonoides'') *''M. megachiliensis'' (formerly in ''Trichosporonoides'') *''M. mellis'' *''M. nigrescens'' (formerly in ''Trichosporonoides'') *''M. oedocephalis'' (formerly in ''Trichosporonoides'') *''M. pollinis'' *''M. spathulata'' (formerly in ''Trichosporonoides'') *''M. suaveolens'' *''M. tomentosa'', an osmophile An osmophile is a microorganism adapted to environments with high osmotic pressures, such as high sugar concentrations. Osmophiles are similar to halophiles (salt-loving organisms) in that a critical aspect of both types of environment is their low ... References { ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Activity
Water activity (''aw'') is the partial vapor pressure of water in a solution divided by the standard state partial vapor pressure of water. In the field of food science, the standard state is most often defined as pure water at the same temperature. Using this particular definition, pure distilled water has a water activity of exactly one. Water activity is the thermodynamic activity of water as solvent and the relative humidity of the surrounding air after equilibration. As temperature increases, ''aw'' typically increases, except in some products with crystalline salt or sugar. Water migrates from areas of high ''aw'' to areas of low ''aw''. For example, if honey (''aw'' ≈ 0.6) is exposed to humid air (''aw'' ≈ 0.7), the honey absorbs water from the air. If salami (''aw'' ≈ 0.87) is exposed to dry air (''aw'' ≈ 0.5), the salami dries out, which could preserve it or spoil it. Lower ''aw'' substances tend to support fewer microorganisms since these get desiccated b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Spoilage
Food spoilage is the process where a food product becomes unsuitable to ingest by the consumer. The cause of such a process is due to many outside factors as a side-effect of the type of product it is, as well as how the product is packaged and stored. Due to food spoilage, one-third of the world's food produced for the consumption of humans is lost every year. Bacteria and various fungi are the cause of spoilage and can create serious consequences for the consumers, but there are preventive measures that can be taken. Bacteria Bacteria are responsible for some of the spoilage of food. When bacteria breaks down the food, acids and other waste products are generated in the process. While the bacteria itself may or may not be harmful, the waste products may be unpleasant to taste or may even be harmful to one's health. There are two types of pathogenic bacteria that target different categories of food. The first type is called ''Clostridium botulinum'' and targets food such as mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Extremophile")
.JPG "Click for more on -> Food Spoilage")