Production of γ-decalactoned by the yeast Yarrowia lipolytica using different ricinoleic acid sources: comparison of different start-up strategies

THEMATICd SYPOSIUM : S 1 :IndustrialdanddFooddMicrobiologydanddBiotechnology

POSTERd PRESENTATIONSd: P 1 – P 71

Productiond ofd

γ-decalactonedbydthedyeastdYarrowiadlipolytica

usingddifferentdricinoleicdaciddsources:dcomparisondofddifferent

start-updstrategies

Gomes,dN.,dAguedo,dM.,dTeixeira,dJ.danddBelo,dI.d IBB-InstitutedfordBiotechnologydanddBioengineering,dCentredfordBiologicaldEngineering,dUni-versidadeddodMinho,dBraga nelmagomes@deb.uminho.pt γ-Decalatonedisdadpeach-likedaromadcompounddwelldknowndindseveraldfood andd beverages,d reasond whyd thed foodd industryd hasd ad highd interestd ind its biotechnologicaldproduction.dOnedofdthedbetterdknowndapplicationsdisdthedbio-transformationdofdricinoleicdacidd(RA)dintodγ-decalactone,dcatalyseddbydyeasts withd GRASd status,d sinced ind thisd cased ad naturald labeld isd conferredd tod the

aroma1_{,d whichd isd important,d consideringd thed increasingd health-d andd}

nutri-tion-consciousdlifestyles2_.d

RAd isd ad hydroxylatedd C18d fattyd acidd thatd ind itsd esterifiedd formd isd thed major

constituentdofdcastordoil,dmakingditdandabundantdcompound1_{.dIndthedpresent}

work,dthedyeastdstraindYarrowiadlipolytica W29danddRAdsourcesdofdcastordoil anddmethyldricinoleatedweredused.d

Twodmethodologiesdhavedbeendtesteddfordthedinoculationdofdthedbiotransfor-mationd mediumd withd eachd substrate,d includingd ord notd thed commond cell washingdstep.dThedhigherdglobaldhydrophobicitydofdcellsdindnon-washeddcells essays,d improvedd thed overalld process.d Castord oild seemedd tod bed ad mored

ap-propriated substrate,d leadingd tod highdγ-decalatoned concentrationsd (≈ 2 g/L),

butdthedproductivitydwasdsmalld(10-14 mg/L/h).dWorkdisdnowdfocuseddondthe productivitydimprovement,dbydbetterdunderstandingdthedalldprocess,dincluding thedroledofdextracellulardenzymes,dsuchdasdlipasesdanddproteases.d

Thednoveldstart-updmethoddallowsdadmoredefficientdprocessdsinceditdremoves thed laborious/slowd stepd ofd washingd cellsd andd higherd productd concentrations aredachieved. 1.dSchrader,dJ.detdal. (2004)dBiotechnol.dLett. 26:463-472. 2.dKrings,dU.danddBerger,dR. G.d(1998)dAppl.dMicrobiol.dBiotechnol.d49:1-8.

Thedconcentrationdofdglucosedanddfructosedinfluencesdthe

productiondofdvolatiledphenolsdbydwinedlacticdaciddbacteria

Silva,dI.,dCampos,dF.,dHogg,dT.danddCouto,dJ.A. CentroddedBiotecnologiadedQuímicadFina,dEscoladSuperiorddedBiotecnologia,dPorto isfranco@esb.ucp.pt Volatiledphenolsdhavedcharacteristicdaromasdwhich,dabovedadcertaindthreshold, havedadnegativedeffectdondthedoveralldaromadofdwine1_{.dDekkera/Brettanomyces} aredrecognizeddasdthedmaindproducerdorganisms,dalthoughdcertaindstrainsdof LacticdAciddBacteriad(LAB)daredalsodcapabledofdproducingdvolatiledphenols2, 3_.dIn thisdwork,dwedstudieddthedinfluencedofdglucosedondthedabilitydofdLABdtodproduce volatiledphenolsdindculturedmediumdsupplementeddwithdp-coumaricdacid.dThe capacityd ofd Lactobacillusd collinoides ESB99d andd L.d plantarum NCFB1752d to

produced4-ethylphenold(4EP)dwasdfounddtodbedhigherdatd3dandd5dgL-1

ofdglu-cosedthandatd20dgL-1

.dThedresultsdsuggestdthatdthedvinylphenoldreductasedac-tivityd isd enhancedd ind thed presenced ofd lowd concentrationsd ofd glucose,d which

maydbedassociateddwithdthedcellsdnecessitydtodregeneratedNAD+_,dpresumably

thed co-enzymed involvedd ind thed reductiond ofd 4-vinylphenold (4VP)d tod 4EP. Whendfructosedwasdaddeddtodthedmedium,dthedreductiondstepdofd4VPdwasdre-strained,dthusdfavouringdthedoutcomedofd4VPdoverd4EP.dThisdeffectdmightdbe relateddwithdthedreductiondofdfructosedintodmannitoldwhichdisdaccompanieddby

thedregenerationdofdNAD+_{.dItdwasdalsodfounddthatdaerobiosis,dindcomparisondto}

anaerobiosis,d notablyd favoursd thed productiond ofd 4VP,d suggestingd thatd O2is

usedd asd electrond acceptord allowingd thed regenerationd ofd NAD+_{.d Thisd study}

showsdthatdthedratiod4VP/4EPdisdconsiderablydaffecteddbydcertaindwinedfactors whichdcoulddbedrelateddtodthedintracellulardNAD+_{/NADHdbalance.} 1.dFugelsang,dK.d(1997)dWinedMicrobiology.dThedChapmand&dHalldEnologydLibrary,dNewdYork,dUSA. 2.dChatonnet,dP.detdal. (1995)dAmericandJournaldofdEnologydanddViticultured46:463-468. 3.dCouto,dJ.detdal. (2006)dAmericandJournaldofdEnologydanddViticulture 57:166-171. 48 R E F E R E N C E S1 /P34 R E F E R E N C E S1 /P33