fermentation | Definition, Process, & Facts - Encyclopedia ...

fermentation, chemical process by which molecules such as glucose are broken down anaerobically. More broadly, fermentation is the foaming that occurs ... fermentation TableofContents fermentation IntroductionAnaerobicbreakdownofmoleculesIndustrialfermentation FastFacts RelatedContent Media Videos Images More MoreArticlesOnThisTopic Contributors ArticleHistory Home Science Biology LifeCycle,Processes&Properties fermentation chemicalreaction Actions Cite verifiedCite Whileeveryefforthasbeenmadetofollowcitationstylerules,theremaybesomediscrepancies. Pleaserefertotheappropriatestylemanualorothersourcesifyouhaveanyquestions. SelectCitationStyle MLA APA ChicagoManualofStyle CopyCitation Share Share Sharetosocialmedia Facebook Twitter URL https://www.britannica.com/science/fermentation GiveFeedback ExternalWebsites Feedback Corrections?Updates?Omissions?Letusknowifyouhavesuggestionstoimprovethisarticle(requireslogin). FeedbackType Selectatype(Required) FactualCorrection Spelling/GrammarCorrection LinkCorrection AdditionalInformation Other YourFeedback SubmitFeedback Thankyouforyourfeedback Oureditorswillreviewwhatyou’vesubmittedanddeterminewhethertorevisethearticle. JoinBritannica'sPublishingPartnerProgramandourcommunityofexpertstogainaglobalaudienceforyourwork! ExternalWebsites KhanAcademy-FermentationandAnaerobicRespiration FoodandAgricultureOrganisationoftheUnitedNations-FermentedFoods:AnAncientTradition BritannicaWebsites ArticlesfromBritannicaEncyclopediasforelementaryandhighschoolstudents. fermentation-Children'sEncyclopedia(Ages8-11) fermentation-StudentEncyclopedia(Ages11andup) Print print Print Pleaseselectwhichsectionsyouwouldliketoprint: TableOfContents Cite verifiedCite Whileeveryefforthasbeenmadetofollowcitationstylerules,theremaybesomediscrepancies. Pleaserefertotheappropriatestylemanualorothersourcesifyouhaveanyquestions. SelectCitationStyle MLA APA ChicagoManualofStyle CopyCitation Share Share Sharetosocialmedia Facebook Twitter URL https://www.britannica.com/science/fermentation Feedback ExternalWebsites Feedback Corrections?Updates?Omissions?Letusknowifyouhavesuggestionstoimprovethisarticle(requireslogin). FeedbackType Selectatype(Required) FactualCorrection Spelling/GrammarCorrection LinkCorrection AdditionalInformation Other YourFeedback SubmitFeedback Thankyouforyourfeedback Oureditorswillreviewwhatyou’vesubmittedanddeterminewhethertorevisethearticle. JoinBritannica'sPublishingPartnerProgramandourcommunityofexpertstogainaglobalaudienceforyourwork! ExternalWebsites KhanAcademy-FermentationandAnaerobicRespiration FoodandAgricultureOrganisationoftheUnitedNations-FermentedFoods:AnAncientTradition BritannicaWebsites ArticlesfromBritannicaEncyclopediasforelementaryandhighschoolstudents. fermentation-Children'sEncyclopedia(Ages8-11) fermentation-StudentEncyclopedia(Ages11andup) By TheEditorsofEncyclopaediaBritannica • EditHistory TableofContents plantproducingcornethanol Seeallmedia KeyPeople: LouisPasteur HansvonEuler-Chelpin SirArthurHarden EduardBuchner ...(Showmore) RelatedTopics: bottlefermentation industrialfermentation tankfermentation bottomfermentation malolacticfermentation ...(Showmore) Seeallrelatedcontent→ fermentation,chemicalprocessbywhichmoleculessuchasglucosearebrokendownanaerobically.Morebroadly,fermentationisthefoamingthatoccursduringthemanufactureofwineandbeer,aprocessatleast10,000yearsold.Thefrothingresultsfromtheevolutionofcarbondioxidegas,thoughthiswasnotrecognizeduntilthe17thcentury.FrenchchemistandmicrobiologistLouisPasteurinthe19thcenturyusedthetermfermentationinanarrowsensetodescribethechangesbroughtaboutbyyeastsandothermicroorganismsgrowingintheabsenceofair(anaerobically);healsorecognizedthatethylalcoholandcarbondioxidearenottheonlyproductsoffermentation.AnaerobicbreakdownofmoleculesInthe1920sitwasdiscoveredthat,intheabsenceofair,extractsofmusclecatalyzetheformationoflactatefromglucoseandthatthesameintermediatecompoundsformedinthefermentationofgrainareproducedbymuscle.Animportantgeneralizationthusemerged:thatfermentationreactionsarenotpeculiartotheactionofyeastbutalsooccurinmanyotherinstancesofglucoseutilization. BritannicaQuiz TypesofChemicalReactions Canyouidentifywhichtypeofchemicalreactionisshown?Testyourknowledgewiththisquiz! Glycolysis,thebreakdownofsugar,wasoriginallydefinedabout1930asthemetabolismofsugarintolactate.Itcanbefurtherdefinedasthatformoffermentation,characteristicofcellsingeneral,inwhichthesix-carbonsugarglucoseisbrokendownintotwomoleculesofthethree-carbonorganicacid,pyruvicacid(thenonionizedformofpyruvate),coupledwiththetransferofchemicalenergytothesynthesisofadenosinetriphosphate(ATP).Thepyruvatemaythenbeoxidized,inthepresenceofoxygen,throughthetricarboxylicacidcycle,orintheabsenceofoxygen,bereducedtolacticacid,alcohol,orotherproducts.ThesequencefromglucosetopyruvateisoftencalledtheEmbden–Meyerhofpathway,namedaftertwoGermanbiochemistswhointhelate1920sand’30spostulatedandanalyzedexperimentallythecriticalstepsinthatseriesofreactions.glycolysisThegenerationofpyruvatethroughtheprocessofglycolysisisthefirststepinfermentation.EncyclopædiaBritannica,Inc.Thetermfermentationnowdenotestheenzyme-catalyzed,energy-yieldingpathwayincellsinvolvingtheanaerobicbreakdownofmoleculessuchasglucose.Inmostcellstheenzymesoccurinthesolubleportionofthecytoplasm.ThereactionsleadingtotheformationofATPandpyruvatethusarecommontosugartransformationinmuscle,yeasts,somebacteria,andplants.IndustrialfermentationIndustrialfermentationprocessesbeginwithsuitablemicroorganismsandspecifiedconditions,suchascarefuladjustmentofnutrientconcentration.Theproductsareofmanytypes:alcohol,glycerol,andcarbondioxidefromyeastfermentationofvarioussugars;butylalcohol,acetone,lacticacid,monosodiumglutamate,andaceticacidfromvariousbacteria;andcitricacid,gluconicacid,andsmallamountsofantibiotics,vitaminB12,andriboflavin(vitaminB2)frommoldfermentation.Ethylalcoholproducedviathefermentationofstarchorsugarisanimportantsourceofliquidbiofuel.TheEditorsofEncyclopaediaBritannicaThisarticlewasmostrecentlyrevisedandupdatedbyAdamAugustyn.