User:Mahta Amanian/sandbox

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Original - "Biomineralization"

Biology[edit]

If present on a super-cellular scale, biominerals are usually deposited by a dedicated organ, which is often defined very early in the embryological development. This organ will contain an organic matrix that facilitates and directs the deposition of crystals.[1] The matrix may be collagen, as in deuterostomes,[1] or based on chitin or other polysaccharides, as in molluscs.[2]

Shell formation in molluscs[edit]

Further information: Mollusc shell
Variety of mollusc shells (gastropods, snails and seashells).

The mollusc shell is a biogenic composite material that has been the subject of much interest in materials science because of its unusual properties and its model character for biomineralization. Molluscan shells consist of 95–99% calcium carbonate by weight, while an organic component makes up the remaining 1–5%. The resulting composite has a fracture toughness ~3000 times greater than that of the crystals themselves.[3] In the biomineralization of the mollusc shell, specialized proteins are responsible for directing crystal nucleation, phase, morphology, and growths dynamics and ultimately give the shell its remarkable mechanical strength. The application of biomimetic principles elucidated from mollusc shell assembly and structure may help in fabricating new composite materials with enhanced optical, electronic, or structural properties.

  1. ^ a b Livingston, B.; Killian, C.; Wilt, F.; Cameron, A.; Landrum, M.; Ermolaeva, O.; Sapojnikov, V.; Maglott, D.; Buchanan, A.; Ettensohn, C. A. (2006). "A genome-wide analysis of biomineralization-related proteins in the sea urchin Strongylocentrotus purpuratus". Developmental Biology. 300 (1): 335–348. doi:10.1016/j.ydbio.2006.07.047. PMID 16987510.
  2. ^ Checa, A.; Ramírez-Rico, J.; González-Segura, A.; Sánchez-Navas, A. (2009). "Nacre and false nacre (foliated aragonite) in extant monoplacophorans (=Tryblidiida: Mollusca)". Die Naturwissenschaften. 96 (1): 111–122. Bibcode:2009NW.....96..111C. doi:10.1007/s00114-008-0461-1. PMID 18843476.
  3. ^ Currey, J. D. (1999). "The design of mineralised hard tissues for their mechanical functions". The Journal of Experimental Biology. 202 (Pt 23): 3285–3294. PMID 10562511.

Edit - "Biomineralization"

Mineral production and degradation in Fungi[edit]

Fungi are a diverse group of organisms that belong to the eukaryotic domain. Fungi play important roles in the biosphere, including bioremediation, which refers to the cleanup of organic and inorganic pollution. In addition, studies of their significant role in geological processes, “geomycology”, has shown that fungi are involved with biomineralization, biodegradation, and metal-fungal interactions. It has been found that fungi deposit minerals with the help of an organic matrix that provides a nucleation site for the growth of biominerals. Fungal growth may produce a Cu-containing mineral precipitate from a mixture of (NH4)2CO3 and CuCl2 found in the presence of proteins. Fungal extracellular proteins aid in the size and morphology of carbonate minerals precipitated by the fungi.[1]

In addition to precipitating carbonate minerals, fungi can also precipitate uranium-containing phosphate biominerals in the presence of organic phosphorus.[2] They produce a hyphal matrix that localizes the uranium minerals. Although uranium is often deemed as toxic towards living organisms, certain fungi, such as Aspergillus niger and Paecilomyces javanicus can tolerate uranium.

Though fungi can produce minerals, they can also degrade them - mainly oxalic-acid producing strains of fungi. Oxalic acid production is increased in the presence of glucose for three organic acid producing fungi - Aspergillus niger, Serpula himantioides, and Trametes versicolor. Through neogenisis of minerals, these fungi have been found to corrode apatite and galena minerals.[3] The order of most to least oxalic acid secreted by the fungi studied are Aspergillus niger, followed by Serpula himantioides, and finally Trametes versicolor. These capabilities of certain groups of fungi have a major impact on corrosion, a costly problem for many industries and the economy.

  1. ^ Li, Qianwei; Gadd, Geoffrey Michael (2017-08-10). "Biosynthesis of copper carbonate nanoparticles by ureolytic fungi". Applied Microbiology and Biotechnology. doi:10.1007/s00253-017-8451-x. ISSN 1432-0614. PMC 5594056. PMID 28799032.{{cite journal}}: CS1 maint: PMC format (link)
  2. ^ Liang, Xinjin; Hillier, Stephen; Pendlowski, Helen; Gray, Nia; Ceci, Andrea; Gadd, Geoffrey Michael (2015-06-01). "Uranium phosphate biomineralization by fungi". Environmental Microbiology. 17 (6): 2064–2075. doi:10.1111/1462-2920.12771. ISSN 1462-2920.
  3. ^ Adeyemi, Ademola O.; Gadd, Geoffrey M. (2005-06-01). "Fungal degradation of calcium-, lead- and silicon-bearing minerals". Biometals. 18 (3): 269–281. doi:10.1007/s10534-005-1539-2. ISSN 0966-0844.

Mahta Amanian (talk) 04:12, 9 October 2017 (UTC)

Edits for Assignment 5[edit]

Fungi are a diverse group of organisms that belong to the eukaryotic domain. Studies of their significant roles in geological processes, “geomycology”, has shown that fungi are involved with biomineralization, biodegradation, and metal-fungal interactions.[1]

In studying fungi's roles in biomineralization, it has been found that fungi deposit minerals with the help of an organic matrix, such as a protein, that provides a nucleation site for the growth of biominerals.[2] Fungal growth may produce a copper-containing mineral precipitate, such as copper carbonate being produced from a mixture of (NH4)2CO3 and CuCl2.[2] The production of the copper carbonate would be produced in the presence of fungal proteins.[2] These fungal proteins that are found extracellularly aid in the size and morphology of carbonate minerals precipitated by the fungi.[2]

In addition to precipitating carbonate minerals, fungi can also precipitate uranium-containing phosphate biominerals in the presence of organic phosphorus that acts a substrate for the process.[3] The fungi produce a hyphal matrix, also known as mycelium, that localizes and accumulates the uranium minerals that have been precipitated.[3] Although uranium is often deemed as toxic towards living organisms, certain fungi, such as Aspergillus niger and Paecilomyces javanicus can tolerate it.

Though minerals can be produced by fungi, they can also be degraded mainly by oxalic-acid producing strains of fungi. Oxalic acid production is increased in the presence of glucose for three organic acid producing fungi - Aspergillus niger, Serpula himantioides, and Trametes versicolor. These fungi have been found to corrode apatite and galena minerals.[4] Degradation of minerals by fungi is carried out through a process known as neogenisis.[5] The order of most to least oxalic acid secreted by the fungi studied are Aspergillus niger, followed by Serpula himantioides, and finally Trametes versicolor. These capabilities of certain groups of fungi have a major impact on corrosion, a costly problem for many industries and the economy.

this is a user sandbox[edit]

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A pathogen has the potential to cause disease.

Notes[edit]

  1. ^ Gadd, Geoffrey M. (2007-01-01). "Geomycology: biogeochemical transformations of rocks, minerals, metals and radionuclides by fungi, bioweathering and bioremediation". Mycological Research. 111 (1): 3–49. doi:10.1016/j.mycres.2006.12.001.
  2. ^ a b c d Cite error: The named reference :0 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference :1 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference :2 was invoked but never defined (see the help page).
  5. ^ Adamo, Paola; Violante, Pietro (2000-05-01). "Weathering of rocks and neogenesis of minerals associated with lichen activity". Applied Clay Science. 16 (5): 229–256. doi:10.1016/S0169-1317(99)00056-3.
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