2-Methylisoborneol

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2-Methylisoborneol
Methylisoborneol.png
Names
IUPAC name
1,2,7,7-tetramethylbicyclo[2.2.1]heptan-2-ol
Other names
2-Methyl-2-bornanol
Identifiers
3D model (JSmol)
Abbreviations MIB
ChEBI
ChemSpider
KEGG
Properties
C11H20O
Molar mass 168.28 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

2-Methylisoborneol (MIB) is an irregular monoterpene derived from the universal monoterpene precursor geranyl pyrophosphate. MIB and the irregular sesquiterpene geosmin together account for the majority of biologically-caused taste and odor outbreaks worldwide [1]. MIB has a distinct earthy or musty odor, which most people can easily smell. The odor detection threshold of MIB is very low, ranging from 0.002 to 0.02 micrograms per liter in water [2]. MIB is also a factor in cork taint in winemaking.

MIB is produced by various blue-green algae (cyanobacteria) and filamentous bacteria in the class Actinomyces, and also some other prokaryotes and eukaryotes. The main genera in the cyanobacteria that have been shown to produce geosmin include Oscillatoria, Phormidium, and Planktothrix, while the main genus in the Actinomyces that produces geosmin is Streptomyces. [3] [4] They give a musty or earthy odor that can be quite strong if an algal bloom is present. Subsequent death of the microorganisms will release MIB that is trapped in the cells. Along with geosmin, the off flavors caused are issues in the seafood industry. This chemical is the major cause of "muddy" or "dirt" flavors in catfish and crawfish.[5] Cyanobacteria can also produce chemical toxins that have been a problem in drinking water in some cases.

Rhodococcus and Comamonas bacteria can degrade 2-methylisoborneol.[6]

References[edit]

  1. ^ Biochemical and Ecological Control of Geosmin and 2-Methylisoborneol in Source Waters, "Applied and Environmental Microbiology", Volume 73, July 2007.
  2. ^ [1], "Watson, W. and Juttner, F. 2019. IWA Publishing 2019. Taste and Odour in Source and Drinking Water: Causes, Controls, and Consequences".
  3. ^ Juttner, F. and Watson, S. (2007). "Biochemical and Ecological Control of Geosmin and 2-Methylisoborneol in Source Waters". Applied and Environmental Microbiology. 73: 4395–4406.CS1 maint: multiple names: authors list (link)
  4. ^ Izaguirre and Taylor (2004). "A Guide to Geosmin and MIB-producing Cyanobacteria in the United States". Water Science and Technology. 49 (9): 19–24.
  5. ^ Lloyd, Steven W; Grimm, Casey C (1999). "Analysis of 2-Methylisoborneol and Geosmin in Catfish by Microwave Distillation−Solid-Phase Microextraction". Journal of Agricultural and Food Chemistry. 47: 164–169. doi:10.1021/jf980419x.
  6. ^ Guttman, Lior; van Rijn, Jaap (15 January 2012). "Isolation of Bacteria Capable of Growth with 2-Methylisoborneol and Geosmin as the Sole Carbon and Energy Sources". Applied and Environmental Microbiology. 78 (2): 363–370. doi:10.1128/AEM.06333-11.