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Biological Hydrogen Production (Algae)
Biohydrogen is H2 that is produced biologically. Interest is high in this technology because H2 is a clean fuel and can be readily produced from certain kinds of biomass, including biological waste. Furthermore some photosynthetic microorganisms are capable to produce H2 directly from water splitting using light as energy source. Besides the promising possibilities of biological hydrogen production, many challenges characterize this technology. First challenges include those intrinsic to H2, such as storage and transportation of an explosive noncondensible gas. Additionally, hydrogen producing organisms are poisoned by O2 and yields of H2 are often low. Biochemical principles The main reactions driving hydrogen formation involve the oxidation of substrates to obtain electrons. Then, these electrons are transferred to free protons to form molecular hydrogen. This proton reduction reaction is normally performed by an enzyme family known as hydrogenases. In heterotrophic organi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae Hydrogen Production
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, ''Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a polyphyletic group because they do not include a common ancestor, and although eukaryotic algae with chlorophyll-bearing plastids seem to ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at normally-encountered concentrations it is odorless. As the source of carbon in the carbon cycle, atmospheric is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared, infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. It is a trace gas Carbon dioxide in Earth's atmosphere, in Earth's atmosphere at 421 parts per million (ppm), or about 0.042% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.028%. Burning fossil fuels is the main cause of these increased concentrations, which are the primary cause of climate change.IPCC (2022Summary for pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioreactor
A bioreactor is any manufactured device or system that supports a biologically active environment. In one case, a bioreactor is a vessel in which a chemical reaction, chemical process is carried out which involves organisms or biochemistry, biochemically active chemical substance, substances derived from such organisms. This process can either be Aerobic organism, aerobic or Anaerobic organism, anaerobic. These bioreactors are commonly cylindrical, ranging in size from litres to cubic metres, and are often made of stainless steel. It may also refer to a device or system designed to grow Cell (biology), cells or Biological tissue, tissues in the context of cell culture. These devices are being developed for use in tissue engineering or biochemical engineering, biochemical/bioprocess engineering, bioprocess engineering. On the basis of mode of operation, a bioreactor may be classified as batch reactor, batch, fed-batch, fed batch or continuous reactor, continuous (e.g. a continuous s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Closed System
A closed system is a natural physical system that does not allow transfer of matter in or out of the system, althoughin the contexts of physics, chemistry, engineering, etc.the transfer of energy (e.g. as work or heat) is allowed. Physics In classical mechanics In nonrelativistic classical mechanics, a closed system is a physical system that does not exchange any matter with its surroundings, and is not subject to any net force whose source is external to the system. A closed system in classical mechanics would be equivalent to an isolated system in thermodynamics. Closed systems are often used to limit the factors that can affect the results of a specific problem or experiment. In thermodynamics In thermodynamics, a closed system can exchange energy (as heat or work) but not matter, with its surroundings. An isolated system cannot exchange any heat, work, or matter with the surroundings, while an open system can exchange energy and matter. (This scheme of definition of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Splitting
Water splitting is the chemical reaction in which water is broken down into oxygen and hydrogen: Efficient and economical water splitting would be a technological breakthrough that could underpin a hydrogen economy. A version of water splitting occurs in photosynthesis, but hydrogen is not produced. The reverse of water splitting is the basis of the hydrogen fuel cell. Water splitting using solar radiation has not been commercialized. Electrolysis Electrolysis of water is the decomposition of water (H2O) into oxygen (O2) and hydrogen (H2): Production of hydrogen from water is energy intensive. Usually, the electricity consumed is more valuable than the hydrogen produced, so this method has not been widely used. In contrast with low-temperature electrolysis, high-temperature electrolysis (HTE) of water converts more of the initial heat energy into chemical energy (hydrogen), potentially doubling efficiency to about 50%. Because some of the energy in HTE is supplied in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, ''Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in embryophyte, land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a Division (taxonomy), division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a Polyphyly, polyphyletic group because they do not include a common ancestor, and although Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydomonas
''Chlamydomonas'' ( ) is a genus of green algae consisting of about 150 species of unicellular organism, unicellular flagellates, found in stagnant water and on damp soil, in freshwater, seawater, and even in snow as "snow algae". ''Chlamydomonas'' is used as a model organism for molecular biology, especially studies of flagellum, flagellar motility and chloroplast dynamics, biogenesis, and genetics. One of the many striking features of ''Chlamydomonas'' is that it contains ion channels (channelrhodopsins) that are directly activated by light. Some FLU (plant gene), regulatory systems of ''Chlamydomonas'' are more complex than their Homology (biology), homologs in Gymnosperms, with evolutionarily related Regulation of gene expression, regulatory proteins being larger and containing additional Protein domain, domains. Molecular phylogeny studies indicated that the traditional genus ''Chlamydomonas'' as defined using morphological data, was polyphyletic within Volvocales. Many s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microalgae
Microalgae or microphytes are microscopic scale, microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine life, marine systems, living in both the water column and sediment. They are unicellular organism, unicellular species which exist individually, or in chains or groups. Depending on the species, their sizes can range from a few micrometers (μm) to a few hundred micrometers. Unlike higher plants, microalgae do not have roots, stems, or leaves. They are specially adapted to an environment dominated by viscous forces. Microalgae, capable of performing photosynthesis, are important for life on earth; they produce approximately half of the atmospheric oxygen and use the greenhouse gas carbon dioxide to grow photoautotrophically. "Marine photosynthesis is dominated by microalgae, which together with cyanobacteria, are collectively called phytoplankton." Microalgae, together with bacteria, form the base of the food web and provid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicobacter
''Helicobacter'' is a genus of gram-negative bacteria possessing a characteristic helical shape. They were initially considered to be members of the genus '' Campylobacter'', but in 1989, Goodwin ''et al.'' published sufficient reasons to justify the new genus name ''Helicobacter''. The genus ''Helicobacter'' contains about 35 species. Some species have been found living in the lining of the upper gastrointestinal tract, as well as the liver of mammals and some birds. The most widely known species of the genus is '' H. pylori'', which infects up to 50% of the human population. It also serves as the type species of the genus. Some strains of this bacterium are pathogenic to humans, as they are strongly associated with peptic ulcers, chronic gastritis, duodenitis, and stomach cancer. ''Helicobacter'' species are able to thrive in the very acidic mammalian stomach by producing large quantities of the enzyme urease, which locally raises the pH from about 2 to a more biocompatible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ralstonia
''Ralstonia'' is a genus of bacteria, previously included in the genus ''Pseudomonas ''Pseudomonas'' is a genus of Gram-negative bacteria belonging to the family Pseudomonadaceae in the class Gammaproteobacteria. The 348 members of the genus demonstrate a great deal of metabolic diversity and consequently are able to colonize a ...''. It is named after the American bacteriologist Ericka Ralston. Ericka Ralston was born in 1944 in Saratoga, California, and died in 2015 in Sebastopol, California. While in graduate school at the University of California at Berkeley, she identified 20 strains of ''Pseudomonas'' which formed a phenotypical homologous group, and named them ''Pseudomonas pickettii'', after M.J. Pickett in the Department of Bacteriology at the University of California at Los Angeles, from whom she had received the strains. Later, ''P. pickettii'' was transferred to the new genus ''Ralstonia'', along with several other species. She continued her research into bacteria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desulfovibrio
''Desulfovibrio'' is a genus of Gram-negative sulfate-reducing bacteria. ''Desulfovibrio'' species are commonly found in aquatic environments with high levels of organic material, as well as in water-logged soils, and form major community members of extreme oligotrophic habitats such as deep granitic fractured rock aquifers. They're also found in the guts of beetles, such as '' Melolontha melolontha'', where they perform sulfate reduction. High amounts of ''Desulfovibrio'' bacteria have been associated with inflammatory bowel disease, bacteremia infections, and Parkinson's disease. Some'' Desulfovibrio'' species have in recent years been shown to have bioremediation potential for toxic radionuclides such as uranium by a reductive bioaccumulation process, such as converting highly water-soluble U(VI) to relatively insoluble U(IV) precipitate, thus removing the toxic uranium from contaminated water. Phylogeny The currently accepted taxonomy is based on the List of Prokaryoti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
