Cellulose

from Wikipedia, the free encyclopedia
Structural formula
Cellulose chair conformation
Glucose dimer, shown in armchair conformation (cellobiose unit)
General
Surname Cellulose
other names
  • CELLULOSE ( INCI )
  • E  460
CAS number 9004-34-6
Monomer β-D- glucose (monomer) cellobiose (dimer)
Molecular formula of the repeating unit C 12 H 20 O 10
Molar mass of the repeating unit 324.28 g mol −1
Brief description

white odorless powder

properties
Physical state

firmly

density

~ 1.5 g / cm 3

solubility

insoluble in water

safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

The cellulose (including cellulose ) is the main component of plant cell walls (mass fraction of about 50%) and thus the most common organic compound and also the most abundant polysaccharide (multiple sugar). Cellulose is also the most abundant biomolecule . It is unbranched and consists of several hundreds to tens of thousands (β-1,4- glycosidically linked ) β- D - glucose or cellobiose units. These high molecular weight cellulose chains assemble to form higher structures which, as tear-resistant fibers in plants, often have static functions. It differs from the polysaccharide chitin , which is also common in nature, in the absence of acetamide groups . Cellulose is important as a raw material for paper production , but also in the chemical industry and other areas.

history

Cellulose was discovered in 1838 by the French chemist Anselme Payen , who isolated it from plants and determined their chemical formula. Cellulose was used by the Hyatt Manufacturing Company in 1870 to make the first thermoplastic , celluloid . Hermann Staudinger determined the structure of cellulose in 1920. Cellulose was chemically synthesized for the first time by S. Kobayashi and S. Shoda in 1992 (without the help of biologically based enzymes ).

Cellulose with structures in the nanometer range (up to 100 nm in diameter) is called nanocellulose . The nanocellulose is divided into three categories: microfibrillated cellulose (MFC), nano-crystalline cellulose (NCC) and bacterial nanocellulose (BNC). The term was first coined in the late 1970s.

chemistry

Cellulose is a polymer ( polysaccharide 'multiple sugar ') made from the monomer cellobiose, which in turn is a disaccharide ('double sugar') and a dimer of the monosaccharide ('simple sugar') glucose. The monomers are linked to one another by β-1,4-glycosidic bonds. Here, too, there is a β-1,4-glycosidic bond, so that glucose is often also defined as a monomer of cellulose.

1,4-glycosidic linkage, selected hydrogen bonds are dashed in blue .

The monomers are linked by a condensation reaction in which two hydroxyl groups (-OH) form a water molecule (H 2 O) and the remaining oxygen atom connects the ring-shaped basic structure ( pyran ring ) of the two monomers. In addition to this strong, covalent bond , the less strong hydrogen bonds are also formed intramolecularly . A cellulose molecule often consists of several thousand glucose units.

properties

Cellulose is insoluble in water and most organic solvents . Solvents such as dimethylacetamide / lithium chloride , N-methylmorpholine-N-oxide , dimethylsulfoxide / tetrabutylammonium fluoride or ammonia / Cu 2 + ( Schweizer reagent ), as well as some ionic liquid , however, capable of dissolving cellulose.

It can be broken down by strong acids in the presence of water with cleavage of the glycosidic bonds down to glucose .

metabolism

biosynthesis

Schematic representation of the cell wall , cellulose microfibrils in light blue

Cellulose is of fundamental importance as a structural substance in most plants. Fibers in woody and non-woody plants consist of a large number of fibrils , which in turn consist of numerous cellulose molecules arranged parallel to one another. Cellulose microfibrils are synthesized in the plasma membrane of a cell in so-called rosette complexes. These contain the enzyme cellulose synthase , which produces β-D- glucans (D-glucose polymers with β-bond) and thereby links the first carbon atom of one D-glucose molecule with the fourth carbon atom of another D-glucose molecule. The production of the glucan chain requires two essential steps. First, sucrose synthase splits the disaccharide (double sugar) sucrose into its monomers glucose and fructose to provide glucose. The glucose is now linked by the cellulose synthase with uridine diphosphate (UDP) to form UDP-glucose . In a further step, the bound glucose is now transferred to the non- reducing sugar of the growing glucan chain. The glucan chain or the enzyme then moves on, so that a further synthesis step can take place.

Cellulose is formed in the plasma membrane and interlinks to form fibrous structures. Then the spatial arrangement of the cellulose fibrils takes place through microtubules .

An important feature of tunicates is a cuticular coat, which is separated from the single-layer epidermis and - unique in the animal kingdom - consists of cellulose.

Dismantling

Since plants build cellulose they produce themselves into their cell walls, they need endogenous cellulases to remodel cell walls, e.g. B. in growth processes . The plant cellulase gene is a very old gene.

use

Plant material consisting mainly of cellulose has been used by humans as fuel for cooking and heating at least since the Paleolithic Age . Cellulose is also an important raw material for material uses, but is also important as a natural or added component of food and feed . Since cellulose occurs in almost all types of plant biomass, it is also important in many other areas, such as B. in wood ( lignocellulose ) as building material etc.

raw material

Cellulose is an important raw material for paper production . The lignin and cellulose-rich wood is used as the raw material . Wood pulp is made from this , which is used for less high quality paper. By removing the lignin content, pulp can be produced, which consists mainly of cellulose and can be used for higher quality papers.

The seed hairs of the cotton bush ( Gossypium herbaceum ) consist of almost pure cellulose.
Close-up of fabric made of viscose ("artificial silk").

In the clothing industry, the plant fibers , which mainly consist of cellulose, are used for various fabrics. Examples are cotton and bast fibers from flax , which are processed into linen .

Another regenerated cellulose material is cellophane (cellulose hydrate), which is a common packaging material in the form of foils. Synthetic cellulose fibers (" rayon ") can also be produced. For this purpose, an alkaline solution of xanthogenized cellulose ("viscose solution") is processed into threads, the so-called regenerated fibers (e.g. viscose ).

A wide variety of cellulose derivatives are used in many ways, such as. B. methyl cellulose , cellulose acetate and cellulose nitrate in the construction, textile and chemical industries. Celluloid , the first thermoplastic , is derived from cellulose nitrate .

Since cellulose is naturally available in large quantities, attempts are being made to use this renewable raw material e.g. B. to make cellulosic ethanol available as a biofuel . Intensive research is currently underway to develop plant biomass , especially wood and straw, for this purpose.

Cellulose can also be used as a natural insulation material mixed with borax (fungicide and flame retardant) . For this purpose, sorted newsprint is first shredded in a mechanical process and treated with fungicides and flame retardants. The cellulose insulation material obtained can be blown in seamlessly and used for thermal insulation and soundproofing. The blowing process has been used in Canada and the USA since around 1940. The advantage of this insulation material is the environmentally friendly production and the further use of sorted newsprint.

In the laboratory it can be used as a filling material for column chromatography when separating mixtures of substances .

food

Animals

Almost all animals - with the exception of a few mollusks , such as a few snails, such as the Roman snail and a few species of termites - including most herbivores, unlike starch, cannot break down cellulose through their own metabolic functions , although both molecules are made up of glucose molecules. These animals only have the enzymes that can split α- 1,4- or α - 1,6 -glycosidic bonds (e.g. in starch) ( amylases ), but not β- 1,4-glycosidic bonds of cellulose ( Cellulases ). This is why these animals (e.g. cows) can only tap into the high energy content of this carbohydrate with the help of endosymbiotic microorganisms that live in their digestive organs.

Cellulose-eating animals then feed on the steadily growing mass of symbionts in their digestive system. Ruminants digest a large part of the cellulose and other polysaccharides in the rumen with the help of anaerobic microorganisms that convert the cellulose into fatty acids. The same applies to horses and water fowl , where processing takes place in the large intestine .

Humans also have no digestive enzymes to break down cellulose. With the aid of anaerobic bacteria of the colon in the first part, the cecum and the ascending colon ( Colon ascendens ) a portion of the cellulose from the food is broken down into short-chain oligosaccharides. They are absorbed through the colon mucosa and used by the metabolism . In addition to hemicelluloses , pectin and lignin , cellulose is an important vegetable fiber in human nutrition.

Some terrestrial crabs, such as the Isopoda, can break down cellulose with the help of endosymbiotic microorganisms. The same goes for insects like silverfish , almost all termites or cockroaches . More than 450 different endosymbionts were identified in 200 termite species examined . Endosymbionts of fossil termites have already been detected directly (in Burmese amber) from the Cretaceous period.

Cellulase detection from animals (termites)

However, reports of cellulase detection from termites contradict the view that animals generally lack cellulases. Some species of termites ( Reticulitermes speratus and Coptotermes formosanus ), the cancer Cherax destructor , the nematode Bursaphelenchus xylophilus and the clams Corbicula japonica and Lyrodus pedicellatus were cellulase genes detected.

Bacteria, fungi and flagellates

Many bacteria , fungi and flagellates can only break down cellulose through their cellulases down to glucose dimer cellobiose . A few protozoa and fungi such as Aspergillus - , Penicillium - and Fusarium TYPES additionally have the necessary β-1,4-glucosidase or Cellobiases which split the cellobiose to glucose. Some wood- decomposing fungi such as Ceriporiopsis subvermispora can also oxidatively break down cellobiose via cellobiose dehydrogenase ( CDH ), an extracellular hemoflavoenzyme . This creates gluconic acid instead of glucose .

The breakdown of cellulose by further hydrolytic enzymes is supported by carbohydrate-binding areas (CBMs) of the enzymes.

The green alga Chlamydomonas reinhardtii can split cellulose and use it to generate energy.

Food additive

Cellulose or cellulose derivatives are also used in the food and pharmaceutical industries, e.g. B. as a thickener , carrier , filler , release agent , coating agent and foam agent . As a food additive , cellulose has the designations E 460 to E 466:

E 460i - microcrystalline cellulose
E 460ii - cellulose powder
E 461 - methyl cellulose
E 463 - hydroxypropyl cellulose
E 464 - hydroxypropylmethyl cellulose
E 465 - ethyl methyl cellulose
E 466 - carboxymethyl cellulose

The detection is carried out by means of a iodine - solution of zinc chloride (blue staining).

See also

literature

  • Hans-Werner Heldt, Birgit Piechulla, Fiona Heldt: Plant biochemistry . 4th edition, Spektrum, Heidelberg / Berlin 2008, ISBN 978-3-8274-1961-3 .
  • Peter Schopfer, Axel Brennicke: Plant Physiology. 7th edition, Spektrum, Heidelberg / Berlin 2010, ISBN 978-3-8274-2351-1 .
  • Lincoln Taiz, Eduardo Zeiger: Physiology of Plants. (Original title: Plant physiology translated by Uta Dreßer), Spektrum, Heidelberg / Berlin 2000, ISBN 3-8274-0537-8 .
  • Dieter Hess: Plant Physiology. 11th completely revised and redesigned edition, UTB 8393 / Ulmer , Stuttgart 2008, ISBN 978-3-8252-8393-3 (UTB) / ISBN 978-3-8001-2885-3 (Ulmer).
  • Fumiaki Nakatsubo: Chemical synthesis of cellulose. In: David N.-S. Hon, Nobuo Shira: Wood and cellulosic chemistry. Issue 2, CRC Press, 2001, ISBN 978-0-8247-0024-9 , limited preview in Google Book Search.

Web links

Individual evidence

  1. ↑ Entry on CELLULOSE in the CosIng database of the EU Commission, accessed on February 16, 2020.
  2. ↑ Entry on E 460: Cellulose in the European database for food additives, accessed on August 6, 2020.
  3. ↑ a b c d e data sheet Cellulose, microcrystalline at AlfaAesar, accessed on June 18, 2019 ( PDF )(JavaScript required) .
  4. ↑ Cellulose data sheet (PDF) from Merck , accessed on June 18, 2019.
  5. ↑ Kenji Kamide: Cellulose and Cellulose Derivatives. Elsevier, 2005, ISBN 978-0-08-045444-3 , p. 1.
  6. ^ RL Crawford: Lignin biodegradation and transformation . John Wiley and Sons, New York 1981, ISBN 0-471-05743-6 .
  7. ↑ Dieter Klemm, Brigitte Heublein, Hans-Peter Fink, Andreas Bohn: Cellulose: Fascinating Biopolymer and Sustainable Raw Material . In: ChemInform . 36, No. 36, 2005. doi : 10.1002 / chin.200536238 .
  8. ↑ Cellulose - Materialinfo on nanopartikel.info, accessed on March 3, 2017.
  9. ↑ AF Turbak, FW Snyder, KR Sandberg: Microfibrillated cellulose, a new cellulose product: Properties, uses and commercial potential. In: J. Appl. Polym. Sci. : Appl. Polym. Symp. (United States), Volume: 37. A. Sarko (Ed.): Symposium on Cellulose and Wood as Future Chemical Feedstocks and Sources of Energy, and General Papers. Proceedings of the Ninth Cellulose Conference, 1982, Wiley, New York City 1983, ISBN 0-471-88132-5 , pp. 815-827.
  10. ^ Lubert Stryer : Biochemistry. 4th edition, Spektrum der Wissenschaft Verlag, corrected reprint, Heidelberg, 1999, ISBN 3-86025-346-8 , p. 497.
  11. ↑ J. Zhang et al. a .: Application of ionic liquids for dissolving cellulose and fabricating cellulose-based materials: state of the art and future trends. In: Materials Chemistry Frontiers issue 7, 2017. doi: 10.1039 / C6QM00348F
  12. ↑ a b entry on cellulose. In: Römpp Online . Georg Thieme Verlag, accessed on August 9, 2013.
  13. ↑ Angus Davison, Mark Blaxter: Ancient origin of glycosyl hydrolase family 9 cellulase genes. In: Molecular Biology and Evolution. Volume 22, No. 5, 2005, pp. 1273-1284, doi: 10.1093 / molbev / msi107 .
  14. ↑ Albert Gossauer : Structure and reactivity of biomolecules. Verlag Helvetica Chimica Acta, Zurich, 2006, ISBN 978-3-906390-29-1 , p. 346.
  15. ↑ Fraunhofer Information Center for Space and Construction (Baufachinformation.de): Organic insulation materials .
  16. ^ Fay L. Myers and DH Northcote: Partial Purification and some Properties of a Cellulase from Helix pomatia. Department of Biochemistry, University of Cambridge, July 23, 1958, In: Biochemical Journal. 71 (4), Apr. 1959, 749-756, doi: 10.1042 / bj0710749 .
  17. ↑ H. Watanabe, Hiroaki Noda, G. Tokuda, N. Lo: A cellulase gene of termite origin. In: Nature . 394, pp. 330-331, 1998, doi: 10.1038 / 28527 .
  18. ↑ Andreas Brune and Moriya Ohkuma: Role of the termite gut macrobiota in symbiotic digestion. In: David Edward Bignell et al. a .: Biology of Termites: A Modern Synthesis. 2nd edition, Springer, 2011, ISBN 978-90-481-3976-7 , Chapter 16, doi : 10.1007 / 978-90-481-3977-4_16 .
  19. ↑ M. Zimmer u. a .: Cellulose digestion and phenol oxidation in coastal isopods (Crustacea: Isopoda). In: Marine Biology. Volume 140, No. 6, 2002, pp. 1207-1213; doi: 10.1007 / s00227-002-0800-2 .
  20. ↑ Martin Zimmer, Werner Topp: Microorganisms and cellulose digestion in the gut of the woodlouse Porcellio scaber. In: Journal of Chemical Ecology. Volume 24, No. 8, 1998, pp. 1397-1408; doi: 10.1023 / A: 1021235001949 .
  21. ↑ N. Chakraborty, GM Sarkar, SC Lahiri: Cellulose degrading capabilities of cellulolytic bacteria isolated from the intestinal fluids of the silver cricket. In: Environmentalist. Volume 20, No. 1, 2000, pp. 9-11, doi: 10.1023 / A: 1006691524607 .
  22. ↑ Moriya Ohkuma: Symbioses of flagellates and prokaryotes in the gut of lower termites. In: Trends in Microbiology. 16 (7): 2008, 345-362, doi: 10.1016 / j.tim.2008.04.004 .
  23. ^ Andreas Brune, Ulrich Stingl: Procaryotic symbionts of termite gut flagellates: Phylogenetic and metabolic implications of a tripartite symbiosis. doi : 10.1007 / 3-540-28221-1_3 , In: Jörg Overmann (Ed.): Progress in Molecular and Subcellular Biology. Volume 41.Springer Verlag, 2005, ISBN 3-540-28210-6 .
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  25. ↑ Michael A. Yamin: Flagellates of the orders Trichomonadida Kirby, Oxymonadida Grasse, and Hypermastigida Grassi & Foa reported from lower termites (Isoptera families Mastotermitidae, Kalotermitidae, Hodotermitidae, Termopsidae, Rhinotermitidae, and Serritermitidae feeding roachryptermitidae) and from the wood Dictyoptera: Cryptocercidae). In: Sociobiology. Volume 4, 1979, pp. 113-117, OCLC 800236058 .
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  28. ↑ Michael M. Martin, Joan S. Martin: Cellulose digestion in the midgut of the fungus-growing termite Macrotermes natalensis: The role of acquired digestive enzymes. In: Science. Volume 199, No. 4336, 1978, pp. 1453-1455, doi: 10.1126 / science.199.4336.1453 .
  29. ↑ Hirofumi Watanabe et al. a .: A cellulase gene of termite origin. In: Nature. Volume 394, No. 6691, 1998, pp. 330-331, doi: 10.1038 / 28527 .
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  31. ^ William Trager: The cultivation of a cellulose-digesting flagellate, Trichomonas termopsidis, and of certain other termite protozoa. In: The Biological Bulletin. Vol. 66, No. 2, 1934, pp. 182-190, JSTOR 1537331 .
  32. ↑ Michael A. Yamin: Cellulose metabolism by the flagellate Trichonympha from a termite is independent of endosymbiotic bacteria. In: Science . Volume 211, No. 4477, 1981, pp. 58-59, doi: 10.1126 / science.211.4477.58 .
  33. ↑ M. Weidenbörner: Lexicon of food mycology . Springer, 1999, ISBN 978-3-540-65241-0 .
  34. ↑ E. Duenhofen: Fermentation, purification and characterization of cellobiose dehydrogenase from Ceriporiopsis subvermispora. Diploma thesis at the University of Natural Resources and Life Sciences, Vienna , 2005, AC04548818 .
  35. ↑ Anthony W. Blake et al. a .: Understanding the biological rationale for the diversity of cellulose-directed carbohydrate-binding modules in prokaryotic enzymes. In: Journal of Biological Chemistry. Volume 281, No. 39, 2006, pp. 29321-29329, doi: 10.1074 / jbc.M605903200 .
  36. ↑ Olga Blifernez-Klassen, Viktor Klassen u. a .: Cellulose degradation and assimilation by the unicellular phototrophic eukaryote Chlamydomonas reinhardtii. In: Nature Communications. 3, article: 1214, 2012, doi: 10.1038 / ncomms2210 , plants eat plants on plant research.de, accessed on March 3, 2017.