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Sporosarcina Pasteurii
''Sporosarcina pasteurii'' formerly known as ''Bacillus pasteurii'' from older taxonomies, is a gram positive bacterium with the ability to precipitate calcite and solidify sand given a calcium source and urea; through the process of microbiologically induced calcite precipitation (MICP) or biological cementation. ''S. pasteurii'' has been proposed to be used as an ecologically sound biological construction material. Researchers studied the bacteria in conjunction with plastic and hard mineral; forming a material stronger than bone. It is a commonly used for MICP since it is non-pathogenic and is able to produce high amounts of the enzyme urease which hydrolyzes urea to carbonate and ammonia. Physiology ''S. pasteurii'' is a gram positive bacterium that is rod-like shaped in nature. It has the ability to form endospores in the right environmental conditions to enhance its survival, which is a characteristic of its bacillus class. It has dimensions of 0.5 to 1.2 microns in wi ... [...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 re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auxotrophy
Auxotrophy ( grc, αὐξάνω "to increase"; ''τροφή'' "nourishment") is the inability of an organism to synthesize a particular organic compound required for its growth (as defined by IUPAC). An auxotroph is an organism that displays this characteristic; ''auxotrophic'' is the corresponding adjective. Auxotrophy is the opposite of prototrophy, which is characterized by the ability to synthesize all the compounds needed for growth. Prototrophic cells (also referred to as the 'wild type') are self sufficient producers of all required metabolites (e.g. amino acids, lipids, cofactors), while auxotrophs require to be on medium with the metabolite that they cannot produce. For example saying a cell is methionine auxotrophic means that it would need to be on a medium containing methionine or else it would not be able to replicate. In this example this is because it is unable to produce its own methionine (methionine auxotroph). However, a prototroph or a methionine prototrophic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbiologically Induced Calcite Precipitation
Microbiologically induced calcium carbonate precipitation (MICP) is a bio-geochemical process that induces calcium carbonate precipitation within the soil matrix. Biomineralization in the form of calcium carbonate precipitation can be traced back to the Precambrian period. Calcium carbonate can be precipitated in three polymorphic forms, which in the order of their usual stabilities are calcite, aragonite and vaterite. The main groups of microorganisms that can induce the carbonate precipitation are photosynthetic microorganisms such as cyanobacteria and microalgae; sulfate-reducing bacteria; and some species of microorganisms involved in nitrogen cycle. Several mechanisms have been identified by which bacteria can induce the calcium carbonate precipitation, including urea hydrolysis, denitrification, sulfate production, and iron reduction. Two different pathways, or autotrophic and heterotrophic pathways, through which calcium carbonate is produced have been identified. There are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halotolerance
Halotolerance is the adaptation of living organisms to conditions of high salinity. Halotolerant species tend to live in areas such as hypersaline lakes, coastal dunes, saline deserts, salt marshes, and inland salt seas and springs. Halophiles are organisms that live in highly saline environments, and require the salinity to survive, while halotolerant organisms (belonging to different domains of life) can grow under saline conditions, but do not require elevated concentrations of salt for growth. Halophytes are salt-tolerant higher plants. Halotolerant microorganisms are of considerable biotechnological interest. Applications Fields of scientific research relevant to halotolerance include biochemistry, molecular biology, cell biology, physiology, ecology, and genetics. An understanding of halotolerance can be applicable to areas such as arid-zone agriculture, xeriscaping, aquaculture (of fish or algae), bioproduction of desirable compounds (such as phycobiliproteins or ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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