TheCeralphaMethod:α-Amylasetestkitissuitableforthespecificmeasurementandanalysisofα-amylaseincerealgrainsandfermentationbroths(fungalandbacterial).
Analysisoffeedenzymes.
McCleary,B.V.(2001).“EnzymesinFarmAnimalNutrition”,(M.BedfordandG.Partridge,Eds.),CABInternational,pp.85-107.
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Enzymesareaddedtoanimalfeedtoincreaseitsdigestibility,toremoveanti-nutritionalfactors,toimprovetheavail
ABIlityofcomponents,andforenvironmentreasons(CampbellandBedford,1992;Walsh
etal.,1993).Awide-varietyofcarbohydrase,protease,phytaseandlipaseenzymesfinduseinanimalfeeds.Inmonogastricdiets,enzymeactivitymustbesufficientlyhightoallowfortherelativelyshorttransittime.Also,theenzymeemployedmustbeabletoresistunfavourableconditionsthatmaybeexperiencedinfeedpreparation(e.g.extrusionandpelleting)andthatexistinthegastrointestinaltract.Measurementoftracelevelsofenzymesinanimalfeedmixturesisdifficult.Independentoftheenzymestudied,manyoftheproblemsexperiencedaresimilar;namely,lowlevelsofactivity,extractionproblemsinactivationduringfeedpreparation,non-specificbindingtootherfeedcomponentsandinhibitionbyspecificfeed-derivedinhibitors,e.g.specificxylanaseinhibitorsinwheatflour(Debyser
etal.,1999).
Measurementofcerealα-Amylase:Anewassayprocedure.
McCleary,B.V.&Sheehan,H.(1987).JournalofCerealScience,6(3),237-251.
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Anewprocedurefortheassayofcerealα-amylasehasbeendeveloped.Thesubstrateisadefinedmaltosaccharidewithanα-linkednitrophenylgroupatthereducingendofthechain,andachemicalblockinggroupatthenon-reducingend.Thesubstrateiscompletelyresistanttoattackbyβ-amylase,glucoamylaseandα-glucosidaseandthusformsthebasisofahighlyspecificassayforα-amylase.Thereactionmixtureiscomposedofthesubstrateplusexcessquantitiesofα-glucosidaseandglucoamylase.Nitrophenyl-maltosaccharidesreleasedonactionofα-amylaseareinstantaneouslycleavedtoglucoseplusfreep-nitrophenolbytheglucoamylaseandα-glucosidase,suchthattherateofreleaseofp-nitrophenoldirectlycorrelateswithα-amylaseactivity.TheassayprocedureshowsanexcellentcorrelationwiththeFarrand,theFallingNumberandthePhadebasα-amylaseassayprocedures.
Anewprocedureforthemeasurementoffungalandbacterialα-amylase.
Sheehan,H.&McCleary,B.V.(1988).BiotechnologyTechnniques,2(4),289-292.
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Aprocedureforthemeasurementoffungalandbacterialα-amylaseincrudeculturefiltratesandcommercialenzymepreparationsisdescribed.Theprocedureemploysend-blocked(non-reducingend)p-nitrophenylmaltoheptaosideinthepresenceofamyloglucosidaseandα-glucosidase,andisabsolutelyspecificforα-amylase.Theassayprocedureissimple,reliableandaccurate.
Measurementofα-AmylaseinCereal,FoodandFermentationProducts.
McCleary,B.V.&Sturgeon,R.(2002).CerealFoodsWorld,47,299-310.
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InGeneral,thedevelopmentofmethodsformeasuringα-amylaseispioneeredintheclinicalchemistryfieldandthentranslatedtootherindustries,suchasthecerealsandfermentationindustries.Inmanyinstances,thistransferoftechnologyhasbeendifficultorimposs
IBLetoachieveduetothepresenceofinterferingenzymesorsugarsandtodifferencesinthepropertiesoftheenzymesbeinganalysed.Thisarticledescribesmanyofthecommonlyusedmethodsformeasuringα-amylaseinthecereals,food,andfermentationindustriesanddiscussessomeoftheadvantagesandlimitationsofeach.
Measurementofα-amylaseactivityinwhitewheatflour,milledmalt,andmicrobialenzymepreparations,usingtheceralphaassay:Collaborativestudy.
McCleary,B.V.,McNally,M.,Monaghan,D.&Mugford,D.C.(2002).JournalofAOACInternational,85(5),1096-1102.
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Thisstudywasconductedtoevaluatethemethodperformanceofarapidprocedureforthemeasurementofα-amylaseactivityinfloursandmicrobialenzymepreparations.Samplesweremilled(ifnecessary)topassa0.5mmsieveandthenextractedwithabuffer/saltsolution,andtheextractswereclarifiedanddiluted.Aliquotsofdilutedextract(containingα-amylase)wereincubatedwithsubstratemixtureunderdefinedconditionsofpH,temperature,andtime.Thesubstrateusedwasnonreducingend-blocked
p-nitrophenylmaltoheptaoside(BPNPG7)inthepresenceofexcessquantitiesof
Thermostableα-glucosidase.TheblockinggroupinBPNPG7preventshydrolysisofthissubstrateby
exo-actingenzymessuchasamyloglucosidase,α-glucosidase,andβ-amylase.Whenthesubstrateiscleavedbyendo-actingα-amylase,thenitrophenyloligosaccharideisimmediatelyandcompletelyhydrolyzedto
p-nitrophenolandfreeglucosebytheexcessquantitiesofα-glucosidasepresentinthesubstratemixture.Thereactionisterminated,andthephenolatecolordevelopedbytheadditionofanalkalinesolutionismeasuredat400nm.AmylaseactivityisexpressedintermsofCeralphaunits;1unitisdefinedastheamountofenzymerequiredtorelease1µmol
p-nitrophenyl(inthepresenceofexcessquantitiesofα-glucosidase)in1minat40°C.Inthepresentstudy,15laboratoriesanalyzed16samplesasblindduplicates.Theanalyzedsampleswerewhitewheatflour,whitewheatflourtowhichfungalα-amylasehadbeenadded,milledmalt,andfungalandbacterialenzymepreparations.Repeatabilityrelativestandarddeviationsrangedfrom1.4to14.4%,andreproducibilityrelativestandarddeviationsrangedfrom5.0to16.7%.
Relationshipbetweenlevelsofdiastaticpowerenzymesandwortsugarproductionfromdifferentbarleycultivarsduringthecommercialmashingprocessofbrewing.
Hu,S.,Yu,J.,Dong,J.,Evans,D.E.,Liu,J.,Huang,S.,Huang,S.,FanW.,Yin,H.&Li,M.(2014).Starch‐Stärke,66(7-8),615-623.
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Thefermentablecarbohydratecompositionofworthasadirectinfluenceonyeastfermentationefficiencyandresultantbeerquality.Inthisstudy,therelationshipbetweendiastaticpowerenzymes(DPE)andtheirwortsugarsproductsduringthecourseofsmall-scale,emulatedcommercialmashingwasinvestigated.Maltsderivedfrom13barleycultivarsweremashedandassayedatfivetimepointsduringmashingforthelevelsofDPEandfermentablesugars.ComparisonsofthepatternsofDPEactivityandwortsugarproductionshowedthattheactivitylevelsofβ-amylaseandlimitdextrinase(LD)duringmashingwerevariablebetweenthe13cultivars,incomparisontothelevelofα-amylaseandresultantcompositionofwortsugars.Moreover,comparisonofpeakDPEactivitiesindicatedthatα-amylasecorrelatedpositivelyandsignificantlywithLD,whilenoobviouscorrelationwasfoundbetweenβ-amylaseandeitherα-amylaseorLD,indicatingthatactivitypatternofα-amylaseandLDwascloselyrelatedduringmashing.Multiplelinearregressionmodels,basedonlevelsoftheDPEasvarioustimepointsduringmashing,thermostabilityofβ-amylaseandmaltKolbachindex,wereabletoexplain42.9%,91.9%,94%,and73.2%ofwortmaltotriose,maltose,glucose,andfermentablesugarcomposition,respectively.Acombinationoftheseinsightsintothedynamicsofstarchhydrolysisduringmashingwillassistbrewersinmaltcultivarselectionandtheadjustmentofmashingconditionssoasoptimizethesugarcontentfortheefficientproductionofhighqualitybeer.
Influenceofgerminationtimeandtemperatureonthepropertiesofryemaltandryemaltbasedworts.
Hübner,F.,Schehl,B.D.,Gebruers,K.,Courtin,C.M.,Delcour,J.A.&Arendt,E.K.(2010).JournalofCerealScience,52(1),72-79.
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TheeffectsofgerminationtimeandtemperatureonthequalityofryemaltandwortsderivedthereofwereinvestigatedusingResponseSurfaceMethodology.Amylolyticandproteolyticenzymeactivitieswereincreasedbylonggerminationperiods,whileβ-glucanaseactivitywasnotinfluenced.TotalandSolubleNitrogencontentwerealsonotsignificantlyaffectedbythevariationsingerminationconditions.FreeAminoNitrogen(FAN)wasfoundinhigheramountsinwortspreparedfromryemaltswithlonggerminationtimes.Extractcontentswerehigherinryemaltthaninthecontrolbarleymaltandcouldbeincreasedbyafavourablegerminationregime,whilenosuchimpactonwortfermentabilitywasfound.Highwortviscositiescouldbesignificantlyreducedbyalonggerminationperiodatlowtemperatures,butwerestillunacceptablyhigh.Thesameconditionsfavouredthedevelopmentofendoxylanaseactivity.Arabinoxylan(AX)accumulatedduringthegerminationprocessandtheirextractabilityincreased.TheresultssuggestthatlongergerminationperiodsresultedinanincreasednumberofAXmoleculeswithlowermolecularmass.Optimalryemaltqualitieswithinthelimitsofthisstudywerefoundforagerminationtimeof144hat10°C,whichresultedinanacceptableFANcontentandthelowestmeasuredviscosity.
Starchdegradationinbuttercupsquash(Cucurbitamaxima).
Irving,D.E.,Shingleton,G.J.&Hurst,P.L.(1999).JournaloftheAmericanSocietyforHorticulturalScience,124(6),587-590.
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Extractableactivitiesofα-amylase,β-amylase,andstarchphosphorylasewereinvestigatedinordertounderstandthemechanismofstarchdegradationinbuttercupsquash(CucurbitamaximaDuchesneexLam.`Delica")withtheultimategoalofimprovingtheconversionofstarchintosweetsugars.Duringrapidstarchsynthesis(0to30daysafterflowering),extractableactivitiesofα-amylaseandβ-amylasewerelow,butthoseofstarchphosphorylaseincreased.Afterharvest,duringripeningat12°C,orinfruitleftinthefield,activitiesofα-amylaseandβ-amylaseincreased.Starchcontained20%to25%amylosesoonafterstarchsynthesiswasinitiatedanduntil49daysafterharvestirrespectiveofwhetherthecropremainedinthefieldorinstorageat12°C.Maltoseconcentrationswerelowpriortoharvest,butlevelsincreasedduringfruitripening.Datasuggeststarchbreakdownishydrolyticinbuttercupsquash,withα-amylasebeingtheprimaryenzymeresponsibleforinitiatingstarchbreakdown.
OptimizingredsorghummaltqualitywhenBacillussubtilisisusedduringsteepingtocontrolmouldgrowth.
Tawaba,J.C.B.,Béra,F.&Thonart,P.(2012).JournaloftheInstituteofBrewing,118(3),295-304.
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PreviousworkhasshownthatBacillussubtilis-S499-basedbiocontroltreatmentsappliedwithoutaerationatthesteepingstageofredsorghummaltingoffergoodmouldreduction,butyieldmaltswithlowlevelsofkeyhydrolyticenzymes.Thusweattemptedtoraisetheselevelsbyaeratingthesteepingliquor,varyingthesteepingtime(from8to40 h)andtemperature(from25to35°C),andcombiningabiocontroltreatmentwithpriorsteepingin0.2%NaOH.AerationprovedparticularlyimportantwheneverB.subtiliscellswerepresentinthesteepliquor.Theoptimaltemperaturesforα-andβ-amylasewere30and25°C,respectively.Byincreasingthesteepingtime,itwaspossibletoimprovetheα-amylaseactivity,buttheβ-amylaseactivitypeakedsharplybetween16and20 h,dependingonthesteepingmedium.Agoodcompromisewassteepinginabiocontrolmediumfor14–16 hat30°C.Combinationsteepingtreatments(0.2%NaOHfor8 hfollowedbybiocontrolfor8 h)yieldedmaltsofaqualityapproachingthataffordedbydilutealkalinetreatment.
Effectofdryingtemperatureandtimeonalpha-amylase,beta-amylase,limitdextrinaseactivitiesanddimethylsulphidelevelofteff(Eragrostistef)malt.
Gebremariam,M.M.,Zarnkow,M.&Becker,T.(2013).FoodandBioprocessTechnology,6(12),3462-3472.
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Teffisagluten-freecerealwithattractivenutritionalprofile.Thisresearchwasaimedtostudytheinfluenceofkilningontheenzymeactivitiesanddimethylsulphide(DMS)levelofDZ-Cr-387teffvarietyandsuggestakilningconditionthatyieldsteffmaltwithlowDMSwithnoorlittledamageonitsenzymeactivities.Themaltsweredriedusingisothermalconditionsat30,40,50,60and70°Cfor40hwithsamplingincertaintimeinterval.Tosetupkilningprogram,twotemperatureregimens18hat30°C + 1hat60°C + 3or5hat65°C(R1)and18hat30°C + 1hat60°C + 3or5hat80°C(R2)wereselected.Resultsfromisothermalkilningindicatedthatenzymeactivities,DMSandmoisturecontentswereaffected(P < 0.05)by=""time=""and=""temperature.=""the=""values=""of=""α-amylase,=""β-amylase,=""limit=""dextrinase=""activities=""and=""dms=""content=""while=""using=""the=""first=""regimen=""(r1)=""with=""3=""h=""curing=""at=""65°c=""were=""68=""u/g,=""440=""u/g,=""1,072=""u/kg=""and=""3.3=""mg/kg,=""respectively.=""whereas=""in=""the=""second=""regimen=""with=""3=""h=""curing=""at=""80°c,=""the=""values=""were=""42=""u/g,=""406=""u/g,=""736=""u/kg=""and=""2.15=""mg/kg,=""respectively.=""prolonged=""curing=""in=""both=""kilning=""regimens=""caused=""an=""adverse=""effect=""on=""the=""amylolytic=""enzyme=""activities.=""r1=""with=""shorter=""curing=""time=""is=""considered=""to=""be=""the=""best=""condition=""in=""preserving=""enzymes.=""the=""enzyme=""activities=""and=""dms=""level=""show=""that=""teff=""can=""be=""an=""alternative=""raw=""material=""for=""production=""of=""gluten-free=""malt.=""> 0.05)>
EngineeringofvesicletraffickingimprovesheterologousproteinsecretioninSaccharomycescerevisiae.
Hou,J.,Tyo,K.,Liu,Z.,Petranovic,D.&Nielsen,J.(2012).MetabolicEngineering,14(2),120-127.
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TheyeastSaccharomycescerevisiaeisawidelyusedplatformfortheproductionofheterologousproteinsofmedicalorindustrialinterest.However,heterologousproteinproductivityisoftenrestrictedduetothelimitationsofthehoststrain.Intheproteinsecretorypathway,theproteintraffickingbetweendifferentorganellesiscatalyzedbythesolubleNSF(N-ethylmaleimide-sensitivefactor)receptor(SNARE)complexandregulatedbytheSec1/Munc18(SM)proteins.Inthisstudy,wereportthatover-expressionoftheSMproteinencodinggenesSEC1andSLY1,improvestheproteinsecretioninS.cerevisiae.EngineeringSec1p,theSMproteinthatisinvolvedinvesicletraffickingfromGolgitocellmembrane,improvesthesecretionofheterologousproteinshumaninsulinprecursorandα-amylase,andalsothesecretionofanendogenousproteininvertase.EnhancingSly1p,theSMproteinregulatingthevesiclefusionfromendoplasmicreticulum(ER)toGolgi,increasesα-amylaseproductiononly.OurstudydemonstratesthatstrengtheningtheproteintraffickinginER-to-GolgiandGolgi-to-plasmamembraneprocessisanovelsecretoryengineeringstrategyforimprovingheterologousproteinproductioninS.cerevisiae.
Imbalanceofheterologousproteinfoldinganddisulfidebondformationratesyieldsrunawayoxidativestress.
Tyo,K.E.,Liu,Z.,Petranovic,D.&Nielsen,J.(2012).
BMCBIOLOGy,10(1),16.
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Background:Theproteinsecretorypathwaymustprocessawideassortmentofnativeproteinsforeukaryoticcellstofunction.Aswell,recombinantproteinsecretionisusedextensivelytoproducemanybiologicsandindustrialenzymes.Therefore,secretorypathwaydysfunctioncanbehighlydetrimentaltothecellandcandrasticallyinhibitproducttitersinbiochemicalproduction.Becausethesecretorypathwayisahighly-integrated,multi-organellesystem,dysfunctioncanhappenatmanylevelsanddissectingtherootcausecanbechallenging.Inthisstudy,weapplyasystemsbiologyapproachtoanalyzesecretorypathwaydysfunctionsresultingfromheterologousproductionofasmallprotein(insulinprecursor)oralargerprotein(α-amylase).
Results:HAC1-dependentandindependentdysfunctionsandcellularresponseswereapparentacrossmultipledatasets.Inparticular,processesinvolving(a)degradationofprotein/recyclingaminoacids,(b)overalltranscription/translationrepression,and(c)oxidativestresswerebroadlyassociatedwithsecretorystress.
Conclusions:Apparentrunawayoxidativestressduetor
ADIcalproductionobservedhereandelsewherecanbeexplainedbyafutilecycleofdisulfideformationandbreakingthatconsumesreducedglutathioneandproducesreactiveoxygenspecies.Thefutilecycleisdominatingwhenproteinfoldingratesarelowrelativetodisulfidebondformationrates.Whilenotstrictlyconclusivewiththepresentdata,thisinsightdoesprovideamolecularinterpretationtoan,untilnow,largelyempiricalunderstandingofoptimizingheterologousproteinsecretion.Thismolecularinsighthasdirectimplicationsonengineeringabroadrangeofrecombinantproteinsforsecretionandprovidespotentialhypothesesfortherootcausesofseveralsecretory-associateddiseases.
EvaluationofexopolysaccharideproducingWeissellacibariaMG1strainfortheproductionofsourdoughfromvariousflours.
Wolter,A.,Hager,A.S.,Zannini,E.,Galle,S.,Gänzle,M.G.,Waters,D.M.&Arendt,E.K.(2014).FoodMicrobiology,37,44-50.
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Thisstudydeterminedexopolysaccharide(EPS)productionbyWeissellacibariaMG1insourdoughspreparedfromgluten-freeflours(buckwheat,oat,quinoaandteff),aswellaswheatflour.Sourdoughs(SD)werefermentedwithoutsucrose,orbyreplacing10%flourwithsucrosetosupportEPSproduction.TheamountofEPSdependedonthesubstrate:highamountsofEPScorrespondingtolowamountsofoligosaccharideswerefoundinbuckwheat(4.2gEPS/kgSD)andquinoasourdoughs(3.2gEPS/kgSD);incontrast,noEPSbutpanose-seriesoligosaccharides(PSO)weredetectedinwheatsourdoughs.Organicacidproduction,carbohydratesandrheologicalchangesduringfermentationwerecomparedtotheEPSnegativecontrolwithoutaddedsucrose.Correspondingtothehighermineralcontentoftheflours,sourdoughsfromquinoa,teffandbuckwheathadhigherbufferingcapacitythanwheat.Fermentablecarbohydratesinbuckwheat,teffandquinoaflourspromotedW.cibariagrowth;indicatingwhyW.cibariafailedtogrowinoatsourdoughs.Endogenousproteolyticactivitywashighestinquinoaflour;α-amylaseactivitywashighestinwheatandteffflours.ProteindegradationduringfermentationwasmostextensiveinquinoaandteffSDreducingproteinpeaks18-29,30-41and43–55kDaextensively.Rheologicalanalysesrevealeddecreaseddoughstrength(AF)afterfermentation,especiallyinsucrose-supplementedbuckwheatsourdoughscorrelatingwithamountsofEPS.HighEPSproductioncorrelatedwithhighprotein,fermentablesugars(glucose,maltose,fructose),andmineralcontentsinquinoaflour.Inconclusion,W.cibariaMG1isasuitablestartercultureforsourdoughfermentationofbuckwheat,quinoaandteffflour.
Anevaluationofexogenousenzymeswithamylolyticactivityfordairycows.
Klingerman,C.M.,Hu,W.,McDonell,E.E.,DerBedrosian,M.C.&KungJr,L.(2009).Journalofdairyscience,92(3),1050-1059.
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Anexperimental(7B)andacommercial(AMA)formulationofenzymes,bothprimarilywithα-amylaseactivity,wereevaluatedforactivityatvariouspHvalues,stabilityinruminalfluid,thepotentialtoimproveinvitroruminalfermentations,andthepotentialtoimproveproductionperformanceoflactatingcows.Whenincubated(40°C)inbufferwithapHbetween5.4and6.0,7Bhadabout10to25timesgreateramylaseactivitythanAMA,andenzymeactivityinthisrangeincreasedby100%for7B,whereasactivitydecreasedbyabout26%forAMA.Bothformulationsmaintainedenzymeactivitywhentheywereincubatedininvitroruminalfermentationsfor24h.After6hofruminalinvitrofermentation,additionsof7Bresultedinlinearincreasesinapparenttotalvolatilefattyacidproductionforflintanddentcornbuthadnoeffectonflourycorn.Inalactationtrial,28Holsteincows(68±31dinmilk,46.9±9.1kgofmilk/d)werefedatotalmixedration(TMR)supplementedwithnothing(CON),alowdoseof7B[7BL,0.88mL/kgofTMRdrymatter(DM)],ahighdoseof7B(7BH,4.4mL/kgofTMRDM),orAMA(0.4g/kgofTMRDM).Theexperimentwasconductedasa4x4Latinsquaredesignwith21-dperiods.Cowsfed7BL,7BH,andAMAatesimilaramountsofDM,andcowsfedthelatter2dietsconsumedmoreDMthandidcowsfedCON.Cowsfed7BLproducedmoremilkthancowsfedCONand7BH,butproducedsimilaramountstocowsfedAMA.Theproductionof3.5%fat-correctedmilkwasgreaterfromcowsfed7BLandAMAcomparedwithcowsfedCON.Thepercentagesofmilkfatandmilkproteinwereunaffectedbytreatment.Total-tractdigestionofDMandorganicmatterweregreaterforcowsfed7BLcomparedwiththosefedCON.Theadditionofexogenousamylaseenzymestothedietsoflactatingdairycowshasthepotentialtoimproveanimalproductivity.