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==Production==
[[Brettanomyces]], [[Lactobacillus]], and [[Pediococcus]] can produce forms of Tetrahydropyridines''Tetrahydropyridine''. In Brettanomyces, 2-acetyl-3,4,5,6-tetrahydropyridine (ATHP) can be metabolized THP is produced by metabolizing the amino acid acids L-Lysine and D-Lysine, along with and ethanol with oxygen having . Oxygen has a stimulatory effect in it's production, although little else is known about it's production in Brettanomyces <ref>[http://www.brettanomycesproject.com/dissertation/introduction/ Yakobson, Chad. The Brettanomyces Project; Introduction. Retrieved 3/10/2015.]</ref><ref>[http://pubs.acs.org/doi/abs/10.1021/jf071243e The Role of Lysine Amino Nitrogen in the Biosynthesis of Mousy Off-Flavor Compounds by Dekkera anomala. Paul R. Grbin, Markus Herderich, Andrew Markides, Terry H. Lee, and Paul A. Henschke. J. Agric. Food Chem., 2007.]</ref>. The level of THP production varies widely between species and strains of ''Brett'', with some strains not producing it at all and some producing very high amounts above taste threshold. Additionally, THP production in the presence of higher glucose and fructose levels, which explains why THP may be seen more often in stuck wine fermentations than wine that has finished fermenting <ref>[http://www.ncbi.nlm.nih.gov/pubmed/18194246 Growth and volatile compound production by Brettanomyces/Dekkera bruxellensis in red wine. Romano A, Perello MC, de Revel G, Lonvaud-Funel A. J Appl Microbiol. 2008 Jun.</ref>. ATHP is further metabolized into 2-ethyltetrahydropyridine (ETHP/ETPY) by Brettanomyces, although not much is known about this metabolic process either <ref>[http://ucce.ucdavis.edu/files/repositoryfiles/Joseph_5_Aromatic_Diverswity_of_Brettanomyces-82350.ppt Joseph, C.M. Lucy. ''Aromatic Diversity of Brettanomyces''. U.C. Davis. Retrieved 3/10/2015.]</ref>. The presence of the "mousy off-flavor" caused by THP appears to be temporary in beer. Although not much is known about the degradation or metabolic break down of THP, it tends to age out of beer after 2-3 months.
Heterofermentative [[Lactobacillus]] spp. can also produce ATHP and ETHP from Lysine and ethanol <ref>Sparrows, Jeff. ''Wild Brews''. Brewers Publications. 2005. Pg. 112.</ref><ref>[https://books.google.com/books?id=tFjsAuo5WocC&pg=PA348&lpg=PA348&dq=lactobacillus+Tetrahydropyridine&source=bl&ots=QUVyoFtIwK&sig=h1cdjB0r1pIRX2Bms8wVA0UiLk4&hl=en&sa=X&ei=4DX_VPz5CsH6oQSAzoGgBA&ved=0CEwQ6AEwCQ#v=onepage&q=lactobacillus%20Tetrahydropyridine&f=false Lahtinen, Ouwehand, Salminen, von Wright. Lactic Acid Bacteria: Microbiological and Functional Aspects, Fourth Edition. Pg 348.]</ref><ref>[http://ajevonline.org/content/37/2/127.short Heresztyn, Tamila. Formation of Substituted Tetrahydropyridines by Species of Brettanomyces and Lactobacillus Isolated from Mousy Wines.]</ref>.