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'''''Pediococcus''''' (often referred to by brewers as "Pedio") are Gram-positive lactic acid bacteria (LAB) used in the production of Belgian style beers where additional acidity is desirable. They are native to plant material and fruits <ref name="ucdavis">[http://wineserver.ucdavis.edu/industry/enology/winemicro/winebacteria/pediococcus_damnosus.html Viticulture & Enology. UC Davis website. Pedioccous damnosus. Retreived Retrieved 07/28/2015.]</ref>, and often found in [[Spontaneous_Fermentation|spontaneously fermented ]] beer as the primary source of lactic acid production (with ''P. damnosus'' being the only species identified in lambic[[Lambic]]) <ref>[http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095384 The Microbial Diversity of Traditional Spontaneously Fermented Lambic Beer. Freek Spitaels, Anneleen D. Wieme, Maarten Janssens, Maarten Aerts, Heide-Marie Daniel, Anita Van Landschoot, Luc De Vuyst, Peter Vandamme. April 18, 2014.]</ref><ref>[[Scientific_Publications#Lambic_and_Spontaneous_Fermentation|Multiple Scientific publications linked on MTF.]]</ref>. It is also seen as a major source of beer contamination in commercial breweries due to its ability to adapt to and survive in beer. The ability to grow in beer is strain dependent rather than species dependent, however , genetic differences indicate that ''P. damnosus'' and ''P. claussenii'' are better adapted to surviving in beer than ''P. pentosaceus'' <ref name="Snauwaert">[http://www.biomedcentral.com/content/pdf/s12864-015-1438-z.pdf Comparative genome analysis of Pediococcus damnosus LMG 28219, a strain well-adapted to the beer environment. Isabel Snauwaert, Pieter Stragier, Luc De Vuyst and Peter Vandamme. 2015.]</ref>. Like many bacteria, Pediococci pediococci have the ability to [https://en.wikipedia.org/wiki/Horizontal_gene_transfer transfer genes horizontally] without reproduction <ref name="Snauwaert"></ref>. They are generally considered to be facultative anaerobes, which means they grow anaerobically but can also grow in the presence of oxygen <ref>[http://textbookofbacteriology.net/lactics.html Lactic Acid Bacteria. Todar's Online Texbook of Bacteriology. Kenneth Todar, PhD. Pg 1. Retrieved 08/09/2015.]</ref>. Some species/strains (including individual strains of ''P. damnosus'') can have their growth and acid production inhibited by oxygen <ref name="NAKAGAWA">[https://www.jstage.jst.go.jp/article/jgam1955/5/3/5_3_95/_article TAXONOMIC STUDIES ON THE GENUS PEDIOCOCCUS. ATSUSHI NAKAGAWA, KAKUO KITAHARA. 1959.]</ref>, while some will have better growth and produce more acid in the presence of oxygen (microaerophilic) <ref>[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC357257/ THE NUTRITION AND PHYSIOLOGY OF THE GENUS PEDIOCOCCUS. Erling M. Jensen and Harry W. Seeley. 1954.]</ref><ref>[http://www.microbialcellfactories.com/content/8/1/3#B5 Pediocins: The bacteriocins of Pediococcipediococci. Sources, production, properties and applications. Maria Papagianni and Sofia Anastasiadou. 2009.]</ref>. Strains found in beer are hop tolerant <ref>[http://www.biomedcentral.com/1471-2164/16/267 Comparative genome analysis of Pediococcus damnosus LMG 28219, a strain well-adapted to the beer environment. Isabel Snauwaert, Pieter Stragier, Luc De Vuyst and Peter Vandamme. April 2015.]</ref>. Due to their continued metabolism of longer chain polysaccharides, acid production will increase with storage time. ''Pediococcus'' can form a [[pellicle]].

''Pediococcus'' may also cause “ropiness” (also called a "sick beer") due to the production of exopolysaccharideswhen exposed to a fresh sugar source. "Ropy" or "sick" beer is more viscous and, in extreme circumstances, can form strands. Sickness effects mostly the mouthfeel and appearance of the beer, and may have no influence on the flavor. It is considered a temporary flaw in sour beer. Some brewers, including Vinnie Cilurzo from Russian River Brewing and some Belgian lambic producers, claim that after the ropiness goes away (generally in 3-6 months <ref name="ropy_time"></ref>) it produces a deeper acidity and mouthfeel, and is viewed as a positive process in the production of sour beer <ref>[http://www.xxlbrewing.com/hb/sour_beer/img_09.html 2007 Cilurzo, Vinnie. AHA Sour Beer presentation by Vinnie Cilurzo. 2007.]</ref>. For other brewers, ropy beer is seen as a nuisance due to the beer needing to be aged for a longer period of time, especially when it occurs shortly after bottling. ''Pediococcus'' species can also produce diacetyl with extended storage time<ref name="Garcia-Garcia" />. ''[[Brettanomyces]] '' can break down exopolysaccharides and diacetyl produced by ''Pediococcus'' and the two are often used together.

See ''[[Lactobacillus]]'', ''[[Brettanomyces]]'', ''[[Saccharomyces]]'', and [[Mixed Cultures]], [[Kveik#Commercial_Availability|Kveik]], and [[Nonconventional Yeasts and Bacteria]] charts for other commercially available cultures.  ==Introduction of Characteristics and Taxonomy==''Pediococcus'' can either improve or detract from fermented food products, including beer, wine, and cider. They play an important role in the fermentation of some meats and cheeses. They tend to be the primary souring microorganism in the production of [[Lambic|Belgian lambic]]. Some species have also been isolated from plants, fruit, and fermenting plant material. In wine, ''P. parvulus'' is the most common species found, and in beer ''P. damnosus'' is the most common. ''P. pentosaceus'' tends to be more hop sensitive than ''P. damnosus'' <ref name="Wade_2018">[https://onlinelibrary.wiley.com/doi/full/10.1111/ajgw.12366 Role of Pediococcus in winemaking. M.E. Wade, M.T. Strickland, J.P. Osborn, C.G. Edwards. 2018. DOI: https://doi.org/10.1111/ajgw.12366.]</ref>.  Currently, there are 11 recognized species of ''Pediococcus''. They are ''P. acidilactici'', ''P. argentinicus'', ''P. cellicola'', ''P. claussenii'', ''P. damnosus'', ''P. ethanolidurans'', ''P. inopinatus'', ''P. parvulus'', ''P. pentosaceus'' (subspecies ''pentosaceus'' and ''intermedius''), ''P. siamensis'', and ''P. stilesii''. ''P. cerevisiae'' was reclassified into either ''P. damnosus'' or ''P. pentosaceus''. Other species of ''Pediococcus'' have also been reclassified to other genera in the last couple of decades. ''P. dextrinicus'' is now classified as ''Lactobacillus dextrinicus'', ''P. urinae-equi'' is now classified as ''Aerococcus urinae‐equi'', and ''P. halophilis'' is now classified as ''Tetragenococcus halophilis'' <ref name="Wade_2018" />. Pediococci are described as coccoidal (spherical) or ovoid (egg-shaped) in shape. They are Gram-positive, non-motile (not capable of moving on their own), and non-spore forming. They are obligate homofermentive and typically do not produce CO₂, ethanol, or acetic acid, although there are a few exceptions to this in the literature. They do not produce [https://en.wikipedia.org/wiki/Catalase catalase] (except for some ''P. pentocaseus'' strains which were reported to have pseudo-catalase activity by Simpson and Taguchi 1995) or [https://en.wikipedia.org/wiki/Oxidase oxidase] enzymes. Because of the way that ''Pedioccous'' cells divide, they often appear stuck together in pairs or clumps. They are the only lactic acid bacteria found in wine and beer to do this, so they are easily identifiable at the genus level under a microscope based on their tendency to clump together. When grown on agar that is supplemented with 100 mg/L of pimaricin, the colonies are white-grey with a diameter of about 1 mm. Ropy strains have a high elasticity, and when touched with a needle, long threads can be drawn and sometimes the colonies completely stick to the needle. See [https://onlinelibrary.wiley.com/doi/full/10.1111/ajgw.12366 table 2 from Wade et al. (2018)] for more species identification indicators and what carbohydrates different species can ferment <ref name="Wade_2018" /><ref name="Oevelen_1979">[https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-37-0034 D. Van Oevelen & H. Verachtert (1979) Slime Production by Brewery Strains of Pediococcus Cerevisiae, Journal of the American Society of Brewing Chemists, 37:1, 34-37, DOI: 10.1094/ASBCJ-37-0034.]</ref>. See also:* [https://wol-prod-cdn.literatumonline.com/cms/attachment/fcb6edb6-00be-4757-822c-be0a341a4191/ajgw12366-fig-0001-m.jpg Microscopy image of ''Pediococcus''.]

| [[Bootleg Biology]]/[[Spot Yeast]] || Sour Weapon P (''Pediococcus pentosaceus '' Blend) || ''P. pentosaceus '' blend || Perfect for acidifying unhopped wort quickly for kettle or “quick” sours. At 98F, it’s capable of achieving a pH of 3.3 within 18 hours. At 84F, it can reach a pH of 3.5 within 24 hours. With more time, a terminal ph pH of 3.1 may be reached. ''P. pentosaceus'' can also be used for long-term sours. It is capable of growing and producing lactic acid in worts with IBUs as high as 30, though it is recommended for unhopped worts as IBUs over 10 may prevent significant quick souring. At ~30 IBU, souring occurs in 2-3 months <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1302981419730069/?comment_id=1870460696315469&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Justin Amaral and Per Karlsson on Bootleg biology Sour Weapon hop tolerance. milk The Funk Facebook group. 11/2/2017.]</ref>. This culture may produce antimicrobials called bacteriocins or pediocins. These can inhibit and kill similar species of bacteria like Lactobacillus and other Pediococcus species in mixed-culture fermentations. Read Bootleg Biology's [https://www.facebook.com/BootlegBiology/photos/a.148869931970401.1073741829.124634287727299/465185997005458/?type=1&theater Facebook post] regarding bacteriocins for more info. No signs of ropiness (exopolysaccharides) have occurred in testing <ref>[http://bootlegbiology.com/product/sour-weapon-pediococcus-pentosaceus-blend/ Bootleg Biology website. Retrieved 05/06/2016.]</ref>. It is still unknown how hops will affect souring in a long term scenario. Bootleg Biology is still researching long term effects and awaiting peoples feedback as of 5/23/2016.

| [[East Coast Yeast]] || ECY33 || ''P. parvulus'' || Isolated from lambic which was refermented with grapes, this strain of ''Pediococcus'' produces lactic acid, diacetyl, and may cause ropiness in beer. Always add ''Brettanomyces'' where ''Pediococcus'' is used <ref name="ecy_website">[http://www.eastcoastyeast.com/wild-stuff.html "Wild Yeast / Brettanomyces / Lactic Bacteria". East Coast Yeast website. Retrieved 04/27/2018.]</ref>. |-| [[Escarpment Laboratories]] || Pediococcus Blend || Two ''Pediococcus'' strains (''P. damnosus'' and ''P. pentosaceus'') || This blend of 2 hop-resistant Pediococcus strains (P. damnosus and P. pentosaceus) is intended for use in long-term souring. Neither strain has been observed to produce exopolysaccharides (EPS). We recommend 15 IBU or less in the first generation.|-| [[Inland Island Brewing & Consulting|Inland Island Yeast Laboratories]] || INISBC-998 || ''P. damnosus '' || Gram positive cocci that produces lactic acid. Also produces diacetyl and several proteins that may cause a "rope" to form in the beer. Rope will disappear with time. Oxygen and hop sensitive. 75-90°F Temperature Range. '''No longer available.'''|-| [[Mainiacal Yeast]] (CLOSED) || MYPP1 || ''P. pentocaceus'' || Isolated from a growing marijuana plant. No production of diacetyl or EPS, with a clean acidity. Ferment at 70-100°F <ref name="Amaral_Mainiacal">Private correspondence with Justin Amaral by Dan Pixley. 01/24/2018.</ref>. Commercial pitches only.|-| [[Mainiacal Yeast]] (CLOSED) || MYPD1 || ''P. damnosus'' || Isolated from a bottle of belgian lambic. Produces diacetyl and EPS, so use in conjunction with ''Brettanomyces''. Ferment at 70-90°F <ref name="Amaral_Mainiacal" />. Commercial pitches only.|-| [[Omega Yeast Labs]] || OYL-606 || ''P. damnosus'' || This modestly hop tolerant Pedio strain produces a clean lactic tang over time. The strain can produce diacetyl so it is often paired with one or more Brett strains (to consume the diacetyl). While more hop tolerant than the Lacto Blend (OYL-605), IBUs over 5-10 IBU may inhibit souring. Souring time can vary depending on IBU level <ref>[https://omegayeast.com/yeast/bacterial-cultures/pediococcus Pediococcus OYL-606. Omega Yeast Labs website. Retrieved 06/11/2019.]</ref>. EPS production is unknown and has not been observed or reported <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2719576444737219/?comment_id=2719963548031842&comment_tracking=%7B%22tn%22%3A%22R%22%7D Adi Hastings. Milk The Funk Facebook group on OYL Pediococcus EPS production. 06/11/2019.]</ref>. Commercial pitches only.|-| [[Propagate Lab]] || MIP-920 || ''P. damnosus'' || Will sour a finished beer over time to a pH of 3.5 - 3.1. It works well at room temperature and is hop tolerant. It may produce ropiness <ref>[http://www.propagatelab.com/mip-920pediodamn Propagate Labs website. MIP-920. Retrieved 06/20/2020.]</ref>.

| [[RVA Yeast Labs]] || RVA 601 || ''P. damnosus '' || Lactic acid bacteria used in souring Belgian-style beers such as gueze and Lambic. Acid production increases with storage. Temperature range is 60-95º F95°F.

| [[White Labs]] || WLP661 || ''P. damnosus '' || High diacetyl (a.k.a. butter) producer and slow growing. Fermentation temp: 70-85°F (21-29.4° C). Attenuation: 65%. Cell count: 50-80 million cells/mL <ref name="WL_cellcounts">Private correspondence with White Labs Customer Service and Dan Pixley. 10/29/2015.</ref>. Homebrew vials contain 35 mL of slurry, and ~1.75-2.8 billion cells per vial <ref name="priess_pitches">[https://www.facebook.com/groups/MilkTheFunk/permalink/1170980479596831/?comment_id=1171066879588191&reply_comment_id=1171595552868657&total_comments=6&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation with Richard Priess regarding WL and Wyeast homebrew pitches. 10/30/2015.]</ref>.

| [[Wyeast]] || 5733 || ''P. damnosus '' (previously listed as ''P. cerevisiae'') || May cause “ropiness” and produce low levels of diacetyl with extended storage time. Temp range: 60-95° F (15-35° C). Cell count: 1.0 x 10⁸ (100 million) cells/mL <ref>[https://drive.google.com/folderview?id=0B8CshC9nxYHdZmE4MmoyLXA2WVk&usp=sharing Wyeast Specifications 2015 Retail Products. 2015.]</ref>. Homebrew packs contain 100-125 mL of slurry, and ~10-12.5 billion cells <ref name="priess_pitches"></ref>.

====[[Bootleg Biology]] on Sour WeaponP====This product, which is a blend of ''Pediococcus pentosaceus'', can be used for a kettle souring process or a mixed fermentation process. Jeff reported good growth results using 2 grams of calcium carbonate (chalk; CaCO3) per liter of wort for starters of Sour Weapon <ref name="mello_starter">[https://www.facebook.com/groups/MilkTheFunk/permalink/1369904163037794/?comment_id=1370329352995275&reply_comment_id=1370751796286364&comment_tracking=%7B%22tn%22%3A%22R5%22%7D Conversation on MTF with Jeff Mello regarding starters for Pediococcus. 08/08/2016.]</ref>. This same formula might benefit other ''Pediococcus'' starters as well. The CaCO3 serves as a buffering agent that keeps the starter pH from getting too low too fast, and is similar to the concept of buffered growth media for ''Lactobacillus'' (see [[Lactobacillus#Samuel_Aeschlimann.27s_Starter_Procedures|''Lactobacillus'' Starter]]).

[[File:Pedio sugarsEMP Pathway.JPGjpg|thumb|300200px|Pedio fermentables <ref>Wine Microbiology. Practical Applications and Procedures. Kenneth C. Fugelsang, Charles G. Edwards.</ref>]] About 90% of sugar metabolized by ''Pediococcus'' produces lactic acid. It does so by homolactic fermentation (same EMP pathway as [[Lactobacillus#Types_of_Metabolismright|''Lactobacillus'' homolactic fermentation]]), although some species/strains can convert glycerol to lactic acid, acetic acid, acetoin, and CO2 under aerobic conditions (''P. damnosus'' is not in this category) <ref>[https://booksonlinelibrary.googlewiley.com/books?id=1b1CAgAAQBAJ&pg=RA2-PA1&lpg=RA2-PA1&dq=pediococcus+damnosus+homolactic&source=bl&ots=myI2alVB78&sig=cG-yWB4GuABQFEtqD2CAyKmU0TE&hl=en&sa=X&ved=0CEAQ6AEwBGoVChMI66C5593-xgIVCVKICh3Pcg7c#v=onepage&q=pediococcus%20damnosus%20homolactic&f=false Encyclopedia of Food Microbiology. Pediococcus. Carl Adoi/full/10. Batt. Academic Press, Sep 28, 1999 .]<1111/ref>ajgw. ''P. damnosus'' can ferment glucose12366 Homofermentative Embden–Meyerhof–Parnas (EMP) pathway for the production of lactic acid, sucroseacetoin, diacetyl and galactose. Some strains of ''P. damnosus'' can ferment maltose 2,3‐butanediol and sucrose <ref name="ucdavis"></ref>acetic acid production from citrate metabolism. The disaccharide trehalose is the preferred carbon source for Pediococci <ref name="Geissler"></ref>Image by Wade et al (2018).]]]

===Growth and Environment===About 90% of sugar metabolized by ''P. damnosusPediococcus'' is sensitive to temperature produces both L- and pHD-lactic acid <ref name="Wade_2018" />. It is unable does so by homolactic fermentation producing primarily lactic acid (same EMP pathway as [[Lactobacillus#Types_of_Metabolism|''Lactobacillus'' homolactic fermentation]]), although some species/strains can convert glycerol to grow at a pH of 8 or higher or at 35°C. The optimal growth occurs at 22°C lactic acid, acetic acid, acetoin, and 5.5 pH. CO2 under aerobic conditions (''P. damnosus'' is sensitive to environments that contain NaCl, and will not grow with concentrations of 4% NaCl in this category) <ref name>[https://books.google.com/books?id=1b1CAgAAQBAJ&pg=RA2-PA1&lpg=RA2-PA1&dq=pediococcus+damnosus+homolactic&source=bl&ots=myI2alVB78&sig=cG-yWB4GuABQFEtqD2CAyKmU0TE&hl=en&sa=X&ved=0CEAQ6AEwBGoVChMI66C5593-xgIVCVKICh3Pcg7c#v=onepage&q=pediococcus%20damnosus%20homolactic&f="ucdavis">false Encyclopedia of Food Microbiology. Pediococcus. Carl A. Batt. Academic Press, Sep 28, 1999 .]</ref>. Most Some strains of ''P. clausseniipentosaceus'' can grow in beerferment five-chain sugars such as xylose to produce acetic acid and lactic acid. About half of the Some strains tested of ''P. damnosushalophilus'' (now reclassified as ''Tetragenococcus halophilis'' ) can grow in beerconvert citric acid into acetic acid and oxaloacetate (oxaloacetate is then further reduced to acetic acid and diacetyl, and none the diacetyl is further reduced to very few strains of ''Pacetoin, and 2,3-butanediol) by producing citrate lyase enzyme. This generally occurs at a slower rate than malolactic fermentation and depends on pH and temperature. acidilactici However, all species in the '', Pediococcus''Pgenus are considered obligatory homofermentative because of the pathways that they use <ref>[http://aem.asm.org/content/81/20/7233.full A Genomic View of Lactobacilli and pediococci Demonstrates that Phylogeny Matches Ecology and Physiology. parvulus'' Jinshui Zheng, Lifang Ruan, Ming Sun and ''PMichael Gänzle. 2015.]</ref><ref name="Wade_2018" /><ref>[https://aem.asm.org/content/53/6/1257.short Citrate Metabolism by Pediococcus halophilus. pentosaceus'' have been found to grow in finished beer Chiyuki Kanbe, Kinji Uchida. 1987.]</ref>.

One study showed that optimal growth was observed in [http://www.neogen.com/Acumedia/pdf/ProdInfo/7406_PI.pdf MRS media] after ~84 hours with an initial pH of 6.7, ===Diacetyl and a final pH of 4.14, which occurred naturally from fermentation. The addition of bacteriological peptone, MnSO4, and Tween 80 also increased activity. Maximum cell densities of Acetoin===''P. damnosus'' are around 4.3 billion cells/mL in MRS media starting at a pH can produce high amounts of 5.5 diacetyl and acetoin during lactic acid production <ref>[httpshttp://wwwonlinelibrary.facebookwiley.com/groupsdoi/MilkTheFunk10.1046/permalinkj.1365-2672.2000.00956.x/1347683325259878/?comment_id=1349386438422900&reply_comment_id=1350340544994156&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Richard Preiss on MTF regarding Pediococcus cell densitypdf Identification of pediococci by ribotyping. R. Satokari, T. Mattila-Sandholm and M.L. Suihko. 07/19/2016Journal of Applied Microbiology 2000, 88, 260–265.]</ref><ref>[http://wwwmmbr.ncbiasm.nlm.nih.govorg/content/77/pubmed2/11851822 Growth optimization 157.full The Microbiology of Pediococcus damnosus NCFB 1832 Malting and the influence of pH Brewing. Nicholas A. Bokulicha, and nutrients on the production of pediocin PD-1Charles W. Nel HA, Bauer R, Vandamme EJ, Dicks LMBamforth. 2001 June 2013.]</ref>, but this is only in optimal conditions. Maximum cell density varies based on Diacetyl is the conditions of the propagation with pH 'buttery' aroma and flavor found in beer (generally not favorable) and nutrient demands being two of the main limiting factors <ref>[https:/in wine (favorable in amounts between 1-4 mg/wwwL).reddit.com/r/Homebrewing/comments/3qp7b7/advanced_brewers_round_table_neva_parker_white/cwh7iqq Neva Parker While other microbes found in beer and wine fermentation (namely ''Saccharomyces cerevisiae'') can also produce diacetyl, Reddit thread. 10/29/2015.]''Pediococcus'' and other lactic acid bacteria are known to be able to produce much higher amounts <ref name="Wade_2018" /ref>.

Although more experiments are probably neededIn lactic acid bacteria, agitation is believed to diacetyl can be an important factor for any species the byproduct of both homofermentative metabolism of sugars as well as the metabolism of microbe (yeast citric acid, and bacteria)it is a way for the cells to regenerate NADP⁺. Gentle stirring on a stir plate or orbital shakerIn either of these two pathways, or frequent gentle manual agitation leads extra pyruvate is turned into alpha-acetolactate which then undergoes an oxidative decarboxylation reaction to produce diacetyl. Diacetyl is often reduced by yeast to faster growth acetoin and /or 2,3-butanediol, which have a higher number threshold and less of organisms. Agitation keeps an impact on the microbes in solutionfinished beer/wine <ref name="Wade_2018" />. It also maximizes In mixed fermentation sour beer, the microbesbreakdown of diacetyl into acetoin and 2,3-butanediol is often thought to be carried out by ''Brettanomyces'' access in a similar way to nutrients and disperses waste evenly''Saccharomyces'' species, but this has not been investigated that we are aware of. In It has been reported that diacetyl reduction is faster at a non-agitated starterlower pH of around 3.5, which is a typical pH range for sour beer and might be one of the microbes are limited contributing factors to the diffusion rate a lack of anecdotal reports of nutrients, leading to a slower and more stressful growth diacetyl in sour beer <ref>[https://wwwonlinelibrary.facebookwiley.com/groupsdoi/MilkTheFunkfull/permalink10.1002/1168024059892473/?comment_id=1174865305875015&reply_comment_id=1176092372418975&total_comments=1&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation jib.381 Michel, M., Meier‐Dörnberg, T., Jacob, F., Methner, F. ‐J., Wagner, R. S., and Hutzler, M. (2016) Review: Pure non‐Saccharomyces starter cultures for beer fermentation with Bryan of Sui Generis Blog about starters a focus on secondary metabolites and agitationpractical applications. J. Inst. Brew., 122: 569– 587. doi: 10. 111002/09/2015jib.381.]</ref><ref name="krogerus_2013">[https://www.researchgate. Although ''Pediococcus'' are generally considered facultative anaerobes and oxygen usually does not negatively affect their growthnet/publication/259331290_125th_Anniversary_Review_Diacetyl_and_its_control_during_brewery_fermentation Krogerus, some strains may show less growth in the presence of oxygen K. and are considered anaerophilicGibson, meaning that the presence of oxygen inhibits their growth B.R. (2013), 125th Anniversary Review: Diacetyl and therefore their acid production) but they can still grow in the presence of O2its control during brewery fermentation. J. Inst. Brew., 119: 86-97. https://doi.org/10.1002/jib.84. The presence of CO2 has a positive effect on acid production <ref name="NAKAGAWA">]</ref> . Therefore, it is generally best practice to seal the starter with an airlock.

====Starter Information====General starter information for commercial Several variables the affect diacetyl and acetoin production have been identified. First of all, some strains of ''Pediococcus'' cultures is limitedspecies produce diacetyl, and others do not. In addition During malolactic fermentation (conversion of citric acid to lactic acid), the various [[Pediococcus#Manufacturer_Tips|starter suggestions by various labs]] regarding their individual culturestemperature at which MLF is conducted can influence whether or not diacetyl is produced. For example, Jeff Mello two studies reported that more diacetyl and acetoin were produced during the MLF in wine at 18°C compared at 25°C. The effect of Bootleg Biology reported good growth results when using temperature is not well understood, but it has been hypothesized that it could be that at lower temperature yeast is less active and thus cannot break the diacetyl down to acetoin and 2 grams of calcium carbonate ,3-butanediol (chalk; CaCO3extended time exposed to active yeast or on lees can reduce diacetyl in wine and probably also beer) per liter of wort for starters of Sour Weapon . If SO₂ is used, it can bind to diacetyl in a form that cannot be tasted, although the SO<ref name="mello_starter"sub>2</refsub>can become unbound and release the diacetyl again. This same formula might benefit other ''Pediococcus'' starters as wellAn increase in citric acid can also lead to more diacetyl under semi-aerobic conditions but not anaerobic conditions. The CaCO3 serves as a buffering agent that keeps the starter pH from getting too low too fast, and is similar to the concept presence of glucose has also been associated with higher levels of buffered growth media for ''Lactobacillus'' (see [[Lactobacillus#Samuel_Aeschlimann.27s_Starter_Procedures|''Lactobacillus'' Starter]])diacetyl production in wine <ref name="Wade_2018" />.

Some strains of ''P. damnosus'' (and other bacteria) can cause a beer (or wine) to go "ropy", also known as "sick" by [[lambic]] brewers (or more specifically as "the fat sickness, "; “la maladie de la graisse” in French <ref>[https://beerbybart.com/2011/04/03/true-lambic-jean-van-roy-cantillon-sick-beer/ True Lambic: Sick beers and the magic of Cantillon. Beer By Bart blog. Gail Ann Williams. 04/03/2011. Retrieved 04/23/2016.]</ref>). Reportedly, ropiness in beer that also has ''Brettanomyces'' (which is traditionally credited with breaking down the ropiness after a period of rest) usually lasts anywhere from 1 week to 3 months, although fewer reports claim that it has lasted as long as 7 months (see reference for different experiences of brewers) <ref name="ropy_time">[https://www.facebook.com/groups/MilkTheFunk/permalink/1132030550158491/ Poll on Milk The Funk regarding how long ropy beer has been observed. 08/20/2015.]</ref>. This "Some species of ''Pediococcus'' and other lactic acid bacteria have been reported to also be able to break down ropiness" is actually caused by production of exopolysaccharides (EPS) in the form of β-glucans (beta glucans)<ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1670311836330357/?comment_id=1670331339661740&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Matt Humbard and Joe Idoni. Milk The Funk Facebook group. A small amount of β-glucan is adequate enough to affect the visible 04/29/2017.]</ref>. The viscosity of ropy beer or wine. The gene known as "dps" has been identified with reported to be higher at the bottom of wooden barrels than near the production top, either due to sedimentation or perhaps more growth of β-glucan/EPS in ''P. damnosusPediococcus'', near the bottom of wooden barrels due to yeast autolysis and the gene "gtf" in ''P. claussenii'' /or less exposure to oxygen <ref name="SnauwaertOevelen_1979"></ref>. Not all Despite the popularity of this talking point about ''Pediococcus'' in brewing, a lot of strains of ''P. damnosusPediococcus''used in brewing don' express the genet seem to produce ropiness, and only ones that do will cause a especially strains sourced from beer to go ropyyeast labs. Although it is not needed to survive in beerFor example, EPS production is probably has importance in biofilm production Richard Preiss of [[Escarpment Laboratories]] reported only seeing ropiness from ''Pediococcus'' sourced from [[lambic]] <ref>[httphttps://catwww.inistfacebook.frcom/groups/MilkTheFunk/permalink/2859721020722760/?aModelecomment_id=afficheN2859868767374652&cpsidtcomment_tracking=23890699 Ethanol tolerance of lactic acid bacteria, including relevance of the exopolysaccharide gene gtf. Pittet V, Morrow K, Ziola B%7B%22tn%22%3A%22R%22%7D Richard Preiss. 2011.]</ref>, and Milk The Funk Facebook group thread on the frequency of ''Pediococci'' that are ropy have been found to be more acid, alcohol, and SO2 tolerant than other ''PediococciPediococcus''caused ropiness. 08/20/2019. The thickness of the ropiness is increased with the presence of malic acid <ref name="ESP">]</ref>.

One study showed [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-37-0034 Oevelen and Verachtert (1979)] demonstrated that ''Brettanommyces bruxllensis'' reduces the production viscosity of ropiness produced by ''Pediococcus'', but that at least one strain of ''Saccharomyces cerevisiae'' does not <ref name="Oevelen_1979" />. The scientists tested two strains of ''B. bruxellensis'', and when either one of βthese strains were co-glucan coincided pitched with the end of the growth phase a strain of ''PediococcusP. damnosus'' (formerly called ''P. While small amounts of β-glucan were produced during growthcerevisiae''), after 2 days at two weeks there was the same level of growth, β-glucan production increased viscosity as growth slowedwhen the ''P. β-glucan production stopped damnosus'' strain was pitched by itself, but at 4 weeks the viscosity was greatly reduced (although the viscosity was still higher than when growth stoppedthere was no ''Pediococcus'' present). This study showed that βWhen they co-glucan production is linked to pitched a strain of ''Saccharomyces cerevisiae'' with the ''PediococcousPediococcus'' growth, producing more towards the end viscosity remained high at 4 weeks, demonstrating that this strain of ''S. cerervisiae'' was not able to reduce the viscosity of the ropiness (it is not known if this strain of growth''S. cerevisiae'' was diastatic or not). This would explain why beer containing The scientists also attempted to stagger the pitch of ''PediococcusBrettanomyces'' often goes ropy shortly , pitching it two weeks after naturally carbonating in the bottle''Pediococcus''. This study found that other variables were not factors resulted in the production very low growth of β-glucan, such differing levels of alcohol (although alcohol interacts with the β-glucan ''Brettanomyces'' and no reduction in a way viscosity due to that limited growth. The limited growth was attributed to the low pH that makes the ''Brettanomyces'' yeast was exposed to at inoculation time. The ''Brettanomyces'' was able to reduce the viscosity seem thicker)when the scientists add another 10 g/L of glucose, and buffered the pH to 4. The study researchers also found that the lack of agitation increased the β-glucan production (wine makers will often agitate or aerate when ropy wine media was exposed to cure the wine from ropiness). A higher initial pH encourages higher growth (5.5+)air, which increases β-glucan productionit immediately disappeared. A lower initial pH (3.5)However, decreases growth and β-glucan production. A higher concentration of glucose increased growth and β-glucan production. Glucose exposing ropy beer to air is needed not an acceptable method for β-glucan dealing with ropiness due to oxidation and acetic acid production. While fructose alone in sour beer when it is mostly insufficient, a combination of glucose and fructose was slightly more efficient than glucose alone exposed to oxygen <ref name="ESPOevelen_1979"></ref>. The exact enzymatic activity for how ''Brettanomyces'' (or other microorganisms) break down EPS from ''Pediococcus'' is not well characterized, but it could be due to alpha-glucosidase activity in those yeasts (see [[Brettanomyces#Carbohydrate_Metabolism_and_Fermentation_Temperature|''Brettanomyces'' metabolism]] and [[Pediococcus#Carbohydrate_Metabolism|Carbohydrate Metabolism]] above).

It has been observed that This "ropiness" is caused by production of exopolysaccharides (EPS) in the form of β-glucans (beta glucans) by some strains ''LactobacillusPediococcus'' and some other lactic acid bacteria species can produce . Ropiness also contains 4-15% proteins and nucleic acid in the form of RNA <ref name="Oevelen_1979" />. The β-glucans are made up of beta 1, 3 linkages and beta 1, 2 branches composed of single units <ref name="Wade_2018" />. A small amount (20-30 mg/L <ref name="Wade_2018" />) of β-glucan is adequate enough to affect the visible viscosity of beer or wine. The gene known as "dps" has been identified with the production of β-glucan/EPS (in ''Lactococcus lactisP. damnosus'', and the gene "gtf" in ''P. claussenii'' <ref name="Snauwaert"></ref>. Not all strains of ''Lactobacillus delbrueckiiP. damnosus''express the gene, and only ones that do will cause a beer to go ropy. Although it is not needed to survive in beer, EPS production is probably has importance in biofilm production <ref>[http://cat.inist.fr/?aModele=afficheN&cpsidt=23890699 Ethanol tolerance of lactic acid bacteria, including relevance of the exopolysaccharide gene gtf. Pittet V, Morrow K, Ziola B. 2011.]</ref>, and pediococci that are ropy have been found to be more acid, alcohol, and SO2 tolerant than other pediococci. The thickness of the ropiness is increased with the presence of malic acid <ref name="ESP"></ref>. While strains of ''P. damnosus''and 'Lactobacillus casei'P. parvulus'' are the ''Pediococcus'' species most associated with ropiness, and some strains of ''Lactobacillus helveticusP. pentosaceus'') have also been found to produce EPS <ref name="ESPWade_2018"></ref>.

[[File:EPSOne study showed that the production of β-glucan coincided with the end of the growth phase of ''Pediococcus''. While small amounts of β-glucan were produced during growth, after 2 days of growth, β-glucan production increased as growth slowed. β-glucan production stopped when growth stopped. This study showed that β-glucan production is linked to ''Pediococcous'' growth, producing more towards the end of growth. This study found that other variables were not factors in the production of β-glucan, such as differing levels of alcohol (although alcohol interacts with the β-glucan in a way that makes the viscosity seem thicker). The study also found that the lack of agitation increased the β-glucan production (wine makers will often agitate or aerate ropy wine to cure the wine from ropiness). A higher initial pH encourages higher growth (5.5+), which increases β-glucan production. A lower initial pH (3.5), decreases growth and β-glucan production. A higher concentration of glucose increased growth and β-glucan production. Glucose is needed for β-glucan production.gif|thumb|300|Exopolysaccharide pathway While fructose alone is mostly insufficient to produce ropiness, a combination of glucose and fructose was slightly more efficient than glucose alone <ref name="ESP"></ref>. The introduction of malic acid, glucose, fructose, and/or nitrogen from things like fruit that is added to sour beer or even sugar added for natural carbonation can trigger ''Pediococcus'' growth and EPS production. Temperature and nitrogen levels also affect how much EPS is produced. One study found that at 12°C both growth and EPS production was much slower than at 25°C. After 29 days in agar media, the EPS in the 12°C samples tended to reach or slightly exceed the levels in the 25°C samples, which developed equivilant levels of EPS (or slightly less) within 7-13 days. Nitrogen levels also play a significant role, according to this study, particularly at lower fermentation temperatures. At 12°C, nitrogen was more important for the formation of EPS than glucose (although glucose was found to be the most important factor in EPS development overall, which is in agreement with the previously cited study). At 25°C nitrogen levels played a significant role in producing EPS, however less so than glucose levels. In general though, higher availability of nitrogen complimented higher levels of glucose to produce more EPS (and faster/higher cell growth) <ref>[httphttps://www.sciencedirect.com/science/article/pii/S0740002004000668 Glucose S0168160503000606 Exopolysaccharide production by Pediococcus damnosus 2.6 in a semidefined medium under different growth conditions. Maite Dueñas, Arantza Munduate, Aidé Perea, Ana Irastorza. 2003.]</ref>. Stress in the environment such as ethanol and SO₂ has also been shown to induce EPS production, and a lack of available glucose has been associated with eliminating the production of EPS (e.g. malolactic fermentation kinetics by ''Pediococcus'' in wine tends not to produce EPS, perhaps due to the lack of glucose in the environment) <ref name="Wade_2018" />. The presence of beta-glucans from barley have been observed to extend both the growth and the viability of ''Lactobacillus'' species in probiotics, indicating that ropiness might be a stress response <ref>[http://www.mdpi.com/1422-0067/15/2/3025/htm Barley β-Glucans-Containing Food Enhances Probiotic Performances of Beneficial Bacteria. Mattia P. Arena, Graziano Caggianiello, Daniela Fiocco, Pasquale Russo, Michele Torelli, Giuseppe Spano, and Vittorio Capozzi. 2014.]</ref><ref>[http://www.mdpi.com/1422-0067/13/5/6026/htm Beta-Glucans Improve Growth, Viability and Colonization of Probiotic Microorganisms. Pasquale Russo, Paloma López, Vittorio Capozzi, Pilar Fernández de Palencia, María Teresa Dueñas, Giuseppe Spano, and Daniela Fiocco. 2012.]</ref>. One study looked at this effect in beta-glucans produced by ''Pediococcus parvulus'' and found that ''L. plantarum'' had a longer viability in a fermented medium with no additional food source when that medium was first fermented with ''P. parvulus'' and EPS was produced. The ''L. plantarum'' strain that was tested did not ferment the beta-glucans. This suggests that there is an interspecies simbiotic relationship between lactic acid bacteria that produce EPS and those that don't, and when EPS is produced (beta-glucans are present) the bacteria survive longer. The study also observed that more EPS was produced in an oat based wort and a rice based wort, while no EPS was produced in a barley based wort, suggesting that different food sources influence whether or not EPS is produced <ref>[http://www.mdpi.com/1422-0067/18/7/1588/htm In Situ β-Glucan Fortification of Cereal-Based Matrices by Pediococcus parvulus. Adrián Pérez-Ramos, María Luz Mohedano, Paloma López, Giuseppe Spano, Daniela Fiocco, Pasquale Russo, and Vittorio Capozzi. 2017.]</ref>. Pittet et al. (2011) found that the presence of the EPS genes in lactic acid bacteria did not correspond with the ability to survive beer-level ethanol levels or higher, which led to the hypothesis that perhaps EPS provides LAB a way to assist in the formation of [[Quality_Assurance#Biofilms|biofilm]], although this has yet to be demonstrated scientifically <ref>[https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-2011-0124-01 Ethanol Tolerance of Lactic Acid Bacteria, Including Relevance of the Exopolysaccharide Gene Gtf. Vanessa Pittet and Kendra Morrow and Barry Ziola. 2011. DOI: https://doi.org/10.1094/ASBCJ-2011-0124-01.]</ref>. Along these same lines, [https://www.academia.edu/27927065/Lysozyme_resistance_of_the_ropy_strain_Pediococcus_parvulus_IOEB_8801_is_correlated_with_beta_glucan_accumulation_around_the_cell Coulon et al. (2012)] reported that an EPS producing strain of ''Pediococcus parvulus'' was more resistant to the antimicrobial enzyme [https://en.wikipedia.org/wiki/Lysozyme lysozyme], which is often added to wine to kill lactic acid bacteria. The beta-glucan EPS formed a "coat" around the cells of the bacteria, thus protecting it from the lysozyme enzyme. When a beta-glucanase enzyme was added to break down the EPS produced by the bacteria, the beta-glucan "coat" disappeared from the cell walls and the lysozyme was once again effective at killing this strain of ''Pediococcus'' <ref>[https://www.academia.edu/27927065/Lysozyme_resistance_of_the_ropy_strain_Pediococcus_parvulus_IOEB_8801_is_correlated_with_beta_glucan_accumulation_around_the_cell Coulon, Joana et al. “Lysozyme Resistance of the Ropy Strain Pediococcus Parvulus IOEB 8801 Is Correlated with Beta-Glucan Accumulation around the Cell.” International Journal of Food Microbiology 159.1 (2012): 25–29. Web.]</ref>. It has been observed that ''Lactobacillus'' species can produce EPS (''Lactococcus lactis'', ''Lactobacillus delbrueckii'', ''Lactobacillus casei'', and ''Lactobacillus helveticus'') <ref name="ESP"></ref>. Some ''Oenococcus oeni'' strains can also produce EPS <ref>[https://pubmed.ncbi.nlm.nih.gov/19659698/ Ciezack G, Hazo L, Chambat G, Heyraud A, Lonvaud-Funel A, Dols-Lafargue M. Evidence for exopolysaccharide production by Oenococcus oeni strains isolated from non-ropy wines. J Appl Microbiol. 2010 Feb;108(2):499-509. doi: 10.1111/j.1365-2672.2009.04449.x. Epub 2009 Jun 30. PMID: 19659698.</ref>. Some species of yeast can also produce EPS, including ''Candida'', ''Cryptococcus'', ''Debaryomyces'', ''Lipomyces'', ''Pichia'' <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2465980936763439/ Zach Taggart. Milk the Funk Facebook group post on EPS from yeast. 01/16/2019.]</ref>, ''Pseudozyma'', ''Rhodotorula'' and ''Sporobolomyces'' <ref name="Gientka_2015">[https://www.researchgate.net/publication/283498621_Exopolysaccharides_from_yeast_insight_into_optimal_conditions_for_biosynthesis_chemical_composition_and_functional_properties_-_review?fbclid=IwAR1X6Y0rnquoF6SD-eH9m6EWpLIefgZJFUJK51NJYBooJWngxEVS2aR3PKE Exopolysaccharides from yeast: insight into optimal conditions for biosynthesis, chemical composition and functional properties - review. Iwona Gientka, Stanisław Błażejak, Stanisław Błażejak, Lidia Stasiak, Lidia Stasiak, Anna Chlebowska-Śmigiel, Anna Chlebowska-Śmigiel. 2015.]</ref>. ====Videos====* [https://www.facebook.com/groups/MilkTheFunk/permalink/4547361381958707/ Highly viscous ropy beer video posted in MTF by Roi Funk Krispen.]* [https://www.facebook.com/groups/MilkTheFunk/permalink/3478055812222608/ Post on MTF by Brandon Jones showing initial ropiness of a beer, and then after aging the ropiness out for 8 weeks.]* [https://www.facebook.com/groups/MilkTheFunk/permalink/1813022388725967/ Other videos on MTF of ropy beer.] ===Bacteriocins===Some strains of ''Pediococcus pentocaseus'' have been found to produce bacteriocins, which are toxins that are produced by the cells that inhibit the growth of other types of bacteria. For example, Bootleg Biology's "Sour Weapon" culture produces antimicrobials called bacteriocins or pediocins (see Bootleg Biology's [https://www.facebook.com/BootlegBiology/photos/a.148869931970401.1073741829.124634287727299/465185997005458/?type=1&theater Facebook post] regarding bacteriocins for more info). These can inhibit and kill similar species of bacteria like ''Lactobacillus'' and other ''Pediococcus damnosus IOEB8801'' species in mixed-culture fermentations. Bacteriocin production can be higher when ''Pediococcus pentocaseus'' is co-fermented with other bacteria than when it is fermented on its own <ref>[https://www.frontiersin.org/articles/10.3389/fmicb.2018.02952/abstract Enhanced Bacteriocin Production by Pediococcus pentosaceus 147 in Co-Culture with Lactobacillus plantarum LE27 on Cheese Whey Broth. Carolina Gutiérrez-Cortés, Héctor Suarez, Gustavo Buitrago, Luis A. Nero and Svetoslav D. Todorov. 2018. DOI: 10.3389/fmicb.2018.02952.]</ref>. A strain of ''Pediococcus pentocaseus'' was found to produce a "class II" enteriocin that inhibits the growth of ''E. coli'' and ''Staphylococcus aureus'' <ref>[https://www.sciencedirect.com/science/article/pii/S0882401017314559 Antibacterial activity of Lactobacillus plantarum isolated from Tibetan yaks. Emilie WallingLei Wang, Hui Zhang, Mujeeb Ur Rehman, Khalid Mehmood, Marguerite DolsXiong Jiang, Mujahid Iqbal, Xiaole Tong, Xing Gao, Jiakui Li. 2017.]</ref>. ''P. damnosus'' also produces an antimicrobial compound called pediocin PD-Lafargue1, Aline Lonvaudwhich can inhibit several bacteria spp including ''O. oeni'' <ref>[http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2672.2001.01486.x/full Growth optimization of Pediococcus damnosus NCFB 1832 and the influence of pH and nutrients on the production of pediocin PD-Funel1. H.A. Nel1, R. Bauer, E.J. Vandamme and L.M.T. Dicks. Food Microbiology Volume 22Jan 2002.]</ref><ref>[http://www.ncbi.nlm.nih.gov/pubmed/15878403 Purification, Issue partial amino acid sequence and mode of action of pediocin PD-1, January a bacteriocin produced by Pediococcus damnosus NCFB 1832. Bauer R, Chikindas ML, Dicks LM. May 2005, Pages 71–78.]</ref>.  See also:* [[Lactobacillus#Bacteriocins|''Lactobacillus'' bacteriocins]].  ===Malolactic Fermentation===See the [[Cider#Microbes|Cider]] page. ===Biogenic Amines===Biogenic amines are produced by all living things and are present in many fermented beverages. High dosages can lead to health issues such as vomiting, headache, asthma, hypotension, and cardiac palpitation. Thus, biogenic amines have been studied intensely <ref name="Wade_2018" />. For more information on biogenic amines in beer in general, see [http://suigenerisbrewing.com/index.php/2019/01/22/biogenic-amines/ "Fact or Fiction – Biogenic Amines in Beer" by Dr. Bryan Heit].

===Other Metabolites===Some strains of lactic acid bacteria, including ''P. damnosusPediococcus'' , can produce high amounts of diacetyl during lactic acid production metabolize amino acids into biogenic amines, and potentially also degrade them <ref>[httphttps://onlinelibrarywatermark.wileysilverchair.com/doi/10.1046/j.13650362-028x-2672.2000.0095660_7_831.x/pdf Identification of pediococci Tyramine Formation by ribotypingPediococcus spp. Rduring Beer Fermentation. SatokariMARIA IZQUlERDO-PULIDO, T. MattilaJOSEP-MIQUEL CARCELLER-ROSA, ABEL MARINE-Sandholm FONT, and M.L. SuihkoCARMEN VIDAL-CAROU. Journal of Applied Microbiology 2000, 88, 260–2651996.]</ref><ref>[httphttps://mmbrwww.asmresearchgate.org/content/77net/2publication/157.full The Microbiology 240429641_Effect_of_tyrosin_on_tyramin_formation_during_beer_fermentation Effect of Malting and Brewingtyrosin on tyramin formation during beer fermentation. Nicholas A. BokulichaMaria Izquierdo-Pulido, and Charles WM. BamforthCarmen Vidal-Carou. June 20132000.]</ref>. ''PThe number of strains capable of producing biogenic amines appears to be very low. damnosus'' also produces an antimicrobial compound called pediocin PD-1, which can inhibit several bacteria spp including ''O. oeni'' <ref> [httphttps://onlinelibrarylink.wileyspringer.com/doi/10.1046/j.1365-2672pdf%2F10.2001.01486.x/full Growth optimization of Pediococcus damnosus NCFB 1832 1007%2FBF01105812 Weiller and the influence Radler (1976)] found that only one out 28 strains of pH and nutrients on the production of pediocin PD-1''P. Hcerevisiae'' (later reclassified to ''P.A. Nel1, R. Bauer, E.J. Vandamme damnosus'' and L''P.M.T. Dickspentosaceus'') produced biogenic amines. Jan 2002.]</ref><ref>[httphttps://www.ncbi.nlm.nih.gov/pubmed/15878403 Purification, partial amino acid sequence and mode 973463 Strickland et al. (2016)] found that out of action multiple species of pediocin PD-1, a bacteriocin produced by Pediococcus damnosus NCFB 1832. Bauer R, Chikindas ML, Dicks LM. May 2005.]</ref>. ''P. clausseniiPediococcus'' tends to produce a smaller amount , only one strain of acetic acid than lactic acid in about a 1:3 ratio. ''P. damnosusinopinatus'' tends to produce produced biogenic amines, and it only lactic acid and no acetic acid <ref name="Geissler">produced 3.3 mg/L of histamine. [httphttps://www.sciencedirect.com/science/article/pii/S0168160515301033 Metabolic strategies S0168160511002893 García‐Ruiz et al. (2011)] reported that 9 out of 85 strains of beer spoilage lactic acid bacteria in beer''P. Andreas Jparvulus'' and ''P. Geisslerpentosaceus'' were able to degrade some biogenic amines (histamine, tyrosine, and putrescine) in culture media, Jürgen Behrbut were unable to do so in wine, Kristina von Kampindicating that any degradation of biogenic amines in wine that might occur is not likely due to lactic acid bacteria, Rudi F. Vogel. 2015.]but due to some other cause <ref name="Wade_2018" /ref>.

===Mixed Culture Influence===:Izquierdo-Pulido et al. (1995) found that out of 35 samples of Spanish lagers contaminated with ''Pediococcus'Editor's note: special thanks , 21 of them had final tyramine levels between 5-10 mg/l, 6 of them had no detected tyramine, and 8 of them had high levels around 25 mg/l, with higher levels being correlated to Richard Preiss higher cell counts of ''Pediococcus''. higher levels of tyramine were associated with higher cell counts of the tyramine-producing strains during smaller bench test fermentations as well. There was no correlation between the presence of wild yeast and tyramine production. Filtration and pasteurization after fermentation had no effect on the levels of tyramine in the final beers <ref>[[Escarpment Laboratorieshttps://watermark.silverchair.com/0362-028x-59_2_175.pdf Biogenic Amine Changes Related to Lactic Acid Bacteria During Brewing. MARIAI ZQUIERDO-PULIDO, JUDIT FONT-FABREGAS, JOSEP-MIQUEL CARCELLER-ROSA, ABEL MARINE-FONT, and CARMENVIDAL-CAROU. 1995.]] for helping to interpret the science referenced this section</ref>.''

De Roos et al (2024) found the ''P. damnosus'', as well as some other bacteria, have been shown to alter the expression in two samples of genes in most, but not all, ''Saccharomyces cerevisiae'' strains (and other ''Saccharomyces'' species and even perhaps [[Brettanomyces]]), in a way that changes how they ferment sugars, and essentially forms a symbiotic environment with lambic had the yeastgenetic capability to produce histamine. Normally ''Saccharomyces'' will only ferment glucose when glucose is present and ignores other sugars such as maltose and maltotriose until the glucose is gone. Biologically speaking, when the presence The total biogenic amine content of glucose in the yeast's environment shuts down the yeast's ability to ferment any other types of sugar besides glucose, this is called "glucose repression" lambic was at levels below that which has been deemed safe by European regulatory bodies <ref name="cross-kingdom">[http://weitzlab.seas.harvard.edu/files/weitzlab/files/2014_cell_jarosz.pdf Cross-Kingdom Chemical Communication Drives a Heritable, Mutually Beneficial Prion-Based Transformation of Metabolism. 2014. Daniel F. Jarosz, Jessica C.S. Brown, Gordon A. Walker, Manoshi S. Datta, W. Lloyd Ung, Alex K. Lancaster, Assaf Rotem, Amelia Chang, Gregory A. Newby,David A. Weitz, Linda F. Bisson, and Susan Lindquist. Cell. 2014 Aug 28;158(5):1083-93.]</ref>. ''Saccharomyces'' and ''Brettanomyces bruxellensis'' (it is currently not known if other ''Brettanomyces'' species other than ''B. bruxellensis'' have this ability) have a gene called "GAF+" that when expressed actually allows it to bypass this "glucose repressionRoosa_2024" and ferment the other sugars simultaneously. Normally this gene is not expressed except by a very small number of cells <ref>[http://www.cell.com/cell/abstract/S0092-8674(14)00974-X An Evolutionarily Conserved Prion-like Element Converts Wild Fungi from Metabolic Specialists to Generalists. Daniel F. Jarosz, Alex K. Lancaster, Jessica C.S. Brown, Susan Lindquist. Cell. Volume 158, Issue 5, p1072–1082, 28 August 2014]</ref>.

When ''PSee also:* [[Spontaneous_Fermentation#Biogenic_Amines|Biogenic amines in spontaneously fermented beer. damnosus'' lives together with ]]* [[Brettanomyces#Biogenic_Amines|Biogenic amine production by ''SaccharomycesBrettanomyces'', a chemical is produced by ''P. damnosus'' that essentially "turns on" the GAF+ gene ]]* [[Wine#Biogenic_Amines|Biogenic amines in ''Saccharomyces''wine.]]* [http://www. Not only does ''Saccharomyces'' then have the ability to ferment other sugars at the same time as glucose, but it produces less alcoholhorscategoriebrewing. Viability over time is also increased in ''Saccharomyces'' cells that express this gene versus those that don'tcom/2019/01/spontaneous-fermentation-and-biogenic. In wild html "Spontaneous fermentation and biogenic amines" by Dr. Dave Janssen; review of grapes, the wild GAF+ ''Saccharomyces'' strains thrived over the other types of fungi several studies that were found on looked at the wild grapes. This led the researchers levels of the referenced study to speculate that the GAF+ gene may play a role biogenic amines in preventing other fungi from thriving. It is thought that this benefits both microorganisms, which are often found together in the wild during fermentation of fruit; the bacteria isn't killed by higher alcohol levelsdifferent beers and their production, and the yeast has a broader food sourcetheir potential flavor contribution. Furthermore, once a ''Saccharomyces'' cell expresses the gene, it will continue to pass this gene expression onto its offspring]* [http://suigenerisbrewing. In winemaking, this is the cause of arrested wine fermentations due to the lower amount of alcohol producedcom/index. For example in the referenced study, the GAFphp/2019/01/22/biogenic- ''Saccharomyces'' cells fermented grape must into a 12% ABV wine, and the GAF+ ''Saccharomyces'' cells fermented the same wine must into an 8% ABV wine <ref name=amines/ "cross-kingdomFact or Fiction – Biogenic Amines in Beer"></ref>by Dr. However, the implications Bryan Heit; an analysis of this biogenic amines in sour spontaneously fermented beer brewing are much different and have yet associated health concerns.]** [https://www.facebook.com/groups/MilkTheFunk/permalink/2570617069633158/?comment_id=2570641549630710&reply_comment_id=2570664762961722&comment_tracking=%7B%22tn%22%3A%22R8%22%7D Follow up from Dr. Heit on MTF on "allergic-like" reactions to be explored scientificallybiogenic amines.]

Of all the ===Other Metabolites===''LactobacillusP. claussenii'' species that have been studied for this behavior (tends to produce a smaller amount of acetic acid than lactic acid in about a 1:3 ratio. ''LP. brevisdamnosus''tends to produce only lactic acid and no acetic acid <ref name="Geissler">[http://www.sciencedirect.com/science/article/pii/S0168160515301033 Metabolic strategies of beer spoilage lactic acid bacteria in beer. Andreas J. Geissler, Jürgen Behr, Kristina von Kamp, ''LRudi F. Vogel. 2015. hilgardii'']</ref>, ''Lalthough some strains have been found to produce small amounts of acetic acid of around 100-300 ppm. This level is slightly below and above flavor thresholds in lager beer (but could be additive with other organisms) <ref>[http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.2010.tb00393. plantarum''x/abstract Isolation, Identification, and ''LCharacterisation of Beer-Spoilage Lactic Acid Bacteria from Microbrewed Beer from Victoria, Australia. kunkeei'') Garry Menz, Christian Andrighetto, Angiolella Lombardi, Viviana Corich, Peter Aldred, only ''LFrank Vriesekoop. 2010. kunkeei'' was shown to induce ]</ref>, but significantly less than the GAF+ genetotal acetic acid often found in gueuze (around 700-2200 ppm <ref>[http://www.horscategoriebrewing.com/2016/07/duivelsbier-of-halle.html Jansen, Dave. Some species Hors Category Blog. "Duivelsbier of Halle". 07/30/2016. Retrieved 01/31/2018.]</ref>) and Flanders reds (300-2300 ppm <ref>[http://www.sciencedirect.com/science/article/pii/S0168160515301896 Microbial diversity and metabolite composition of bacteria from the genres ''Staphylococcus''Belgian red-brown acidic ales. Isabel Snauwaert, ''Micrococcus''Sanne P. Roels, ''Bacillus''Filip Van Nieuwerburg, ''Listeria''Anita Van Landschoot, ''Paenibacillus''Luc De Vuyst, Peter Vandamme. 2015.]</ref>). ''GluconobacterPediococcus'', also carries the decarboxylase enzyme (PAD) which converts hydroxycinnamic acid (ferulic acid) into phenols (4-vinyl guaiacol) <ref name="lentz_2018">[http://www.mdpi.com/2311-5637/4/1/20/html#B13-fermentation-04-00020 The Impact of Simple Phenolic Compounds on Beer Aroma and Flavor. Michael Lentz. 2018. doi: 10.3390/fermentation4010020.]</ref>. While ''SinorhizobiumPediococcus''has been linked to the creation of acrolein via the metabolism of glycerol, evidence supports that this is very rare in ''EscherichiaPediococcus''species. In wine, acrolein reacts with anthocyanins and other phenols to produce an intense bitterness. Acrolein production in wine has been linked to some strains of ''SerriatiaLactobacillus'', and all . Some strains of ''Pediococcus'' species tested also influenced have been found to metabolize gylcerol in beer and wine under aerobic and semi-aerobic environments, but the GAF+ gene metabolism of glycerol in ''Saccharomyces'' the presence of oxygen results in the production of lactic acid, acetic acid, diacetyl, and 2,3-butanediol, and not acrolein <ref name="cross-kingdomWade_2018"></ref>.