Production of mycelial biomass by the Amazonian edible mushroom Pleurotus albidus

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Industrial

Microbiology

Production

of

mycelial

biomass

by

the

Amazonian

edible

mushroom

Pleurotus

albidus

Larissa

de

Souza

Kirsch,

Ana

Júlia

Porto

de

Macedo,

Maria

Francisca

Simas

Teixeira

CultureCollectionDPUA(ParasitologyDepartmentofAmazonasUniversity)/FederalUniversityofAmazonas,Manaus,Amazonas, Brazil

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t

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o

Received10April2015 Accepted9November2015 Availableonline21April2016 AssociateEditor:GiseleMonteirode Souza Keywords: Pleurotusalbidus Submergedfermentation Mycelialbiomass Factorialdesign

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Ediblemushroomspeciesareconsideredasanadequatesourceoffoodinahealthydiet duetohighcontentofprotein,fiber,vitamins,andavarietyofminerals.The representa-tivesofPleurotusgenusarecharacterizedbydistinctgastronomic,nutritional,andmedicinal propertiesamongtheediblemushroomscommercializedworldwide.Inthepresentstudy, thegrowthofmycelialbiomassofPleurotusalbiduscultivatedinsubmergedfermentation wasevaluated.Saccharose,fructose,andmaltosewerethethreemaincarbonsourcesfor mycelialbiomassformationwithcorrespondingyieldsof7.28gL−1,7.07gL−1,and6.99gL−1. Inorganicnitrogensourcesdidnotstimulategrowthandtheoptimalyieldwassignificantly higherwithyeastextract(7.98gL−1).Thefactorialdesignusedtoevaluatetheinfluenceof saccharoseandyeastextractconcentration,agitationspeed,andinitialpHindicatedthatall variablessignificantlyinfluencedtheproductionofbiomass,especiallytheconcentration ofsaccharose.Thegreateramountofsaccharoseresultedintheproductionofsignificantly morebiomass.Thehighestmycelialbiomassproduction(9.81gL−1)wasreachedinthe mediumformulatedwith30.0gL−1saccharose,2.5gL−1yeastextract,pH7.0,andaspeed ofagitationat180rpm.Furthermore,P.albidusmanifesteddifferentaspectsof morphol-ogyandphysiologyunderthegrowthconditionsemployed.Mediacompositionaffected mycelialbiomassproductionindicatingthatthediversificationofcarbonsourcespromoted itsimprovementandcanbeusedasfoodorsupplement.

©2016SociedadeBrasileiradeMicrobiologia.PublishedbyElsevierEditoraLtda.Thisis anopenaccessarticleundertheCCBY-NC-NDlicense(http://creativecommons.org/

licenses/by-nc-nd/4.0/).

Introduction

Pleurotus albidus (Berk.) is a speciesthat occurs in Mexico, Argentina, and Brazil. It is glabrous, white to cream col-oredandpresentsinfundibuliformandcircularpileus,deeply

∗ _{Correspondingauthor.}

E-mail:mteixeira@ufam.edu.br(M.F.S.Teixeira).

decurrentlamella,stipeflutedupwardthroughlamellarbases, taperingdownward,usuallycurved-ascendant,dullwhiteand occasionallywithhairsatthebase.1–3_{ThePleurotusspecies,}

commonlyknownasoystermushrooms,havegastronomic, nutritional, and medicinal propertiesand are growninthe temperateandtropicalrainforests.Nowadays,seventyspecies

http://dx.doi.org/10.1016/j.bjm.2016.04.007

1517-8382/©2016SociedadeBrasileiradeMicrobiologia.PublishedbyElsevierEditoraLtda.ThisisanopenaccessarticleundertheCC BY-NC-NDlicense(http://creativecommons.org/licenses/by-nc-nd/4.0/).

ofthis genusare reported, but onlyfew ofthemare com-mercialized,includingP.ostreatus,P.florida,P.sajor-caju,and

P.eryngii.4

Ithaslongbeenknownthatmushroomsdevelopbiomass throughdegradingcelluloseandligninbytheactionofspecific enzymes under optimal conditions.5,6 _{They can be}

culti-vated at large scale using techniques of solid state and submergedcultures.Bothmethodsuseagroindustrialwaste, althoughinsubmergedfermentation,theconditionsare mon-itoredwithgreater precisionwhencomparedtosolid state fermentation.7,8

Submerged fermentation isa viable alternative for effi-cientPleurotusbiomassproduction.Thisprocesshasanumber ofadvantages,suchasa bettercontrolofphysicochemical parameters,aswellasthepotentialforhighbiomass produc-tioninacompactspace,shortergrowthtime,andindependent ofseasonality.9,10

InsubmergedfermentationofPleurotus,nofruitingbody production occurs, and the mycelial biomass develops in two forms: filamentous and pellet. Pellets are character-ized by mycelia development into spherical aggregates, which are a branched and partially intertwined network of hyphae.11,12 _{The filamentous form consists of hyphae}

homogenouslyspreadintheculturemediumwhichismore viscousthanthat ofthe pelletform.Themycelialbiomass produced by submerged fermentation can be used as an inoculum source for mushroom production in semi-solid fermentations,1infoodadditives,andforextractionof antimi-crobialcompounds,flavorings,polysaccharides,antioxidants, etc.10

Aimedatthe improvementofPleurotuscultivation tech-nology, the present study investigated the influence of physicochemicalparametersofsyntheticmediaonmycelial biomassproductionbyP.albidusinsubmergedfermentation.

Material

and

methods

Fungus

P.albidusDPUA1692wasobtainedfromFederalUniversityof AmazonasDPUACultureCollection,Brazil.Allstockcultures were maintained on a potato dextrose agar (PDA) supple-mentedwith0.5%(w/v)yeastextract(YE)(HiMedia,Mumbai, India)slant,subculturedandincubatedat25◦Cforeightdays inthedarkandthenstoredat4◦C.13

Effectofinoculumvolumeonmycelialbiomassproduction

An aqueous homogenate of mycelium, previously sub-cultured on PDA+YE, was prepared using 50mL of sterilized distilled water (per dish) in a blender. Dif-ferent volumes (0.5, 1.0, 2.0, 4.0, and 6.0mL) of the mycelial homogenate were added into Erlenmeyer flasks (125mL) containing 50mL of standard medium (SM): KH2PO4 (1.0gL−1), MgSO4·7H2O (0.5gL−1), peptone

(10.0gL−1), and glucose (20.0gL−1) at pH 6.0. The flasks were incubated for five days at 25◦C, under aerobic conditions at 150rpm, and tests were carried out in triplicate.14

Effectofcarbonandnitrogensourcesonmycelialbiomass

production

Following nutrients were analyzed: glucose,fructose, malt-ose,saccharose,andlactose,ascarbonsources;andpeptone, yeastextract,tryptone,sodiumnitrate andammonium sul-fate,asnitrogensources.TheglucoseandpeptoneintheSM werereplacedseparatelyaccordingtothecarbonandnitrogen sourcesmentioned.Theaqueoushomogenateofmycelium (6.0mL)wasaddedtotheflasks,andsubmergedfermentation wasperformedasmentionedabove.

Determinationofdrycellmass

Attheendoffermentation,biomasswascollectedbyvacuum filtration,washedthreetimeswithdistilledwater,anddried at70◦Cfordry-weightquantification.15

Determinationoftotalcarbohydrates

Thetotalcarbohydrateconcentrationwasdetermined colori-metricallybythephenol-sulfuricacidmethodaccordingtothe protocoldescribedbyDuboisetal.16

Conversionfactorofsubstratetobiomass,yieldand

productivity

Theconversionfactorofsubstratetobiomassandtheyield and productivity were calculated according to Confortin etal.17

The conversion factor of substrate to biomass was expressedingramsofmycelialbiomassproducedpergram ofsubstrateconsumed(gg−1):

Y(X/S)=X_Sf−Xi

i−Sf

(1) whereXfandXiarefinalandinitialbiomassconcentration,

respectively,andSiandSfareinitialandfinalsugar

concen-tration,respectively.

Theyieldwasexpressedingramsofmycelialbiomass pro-ducedpergram ofsubstrate initiallypresentintheculture medium(gg−1):

Y(r/S)=Xf_S−Xi i

(2) Theproductivity in biomasswas expressedin gramsof mycelialbiomassproducedpertime(gL−1h−1)17_:

PX= Xf−_t Xi (3)

wheretistheincubationtime.

Factorialdesignandstatisticalanalysis

A24 _{factorialdesignwasusedtoevaluatesaccharose}

con-centration,yeastextractconcentration,agitationspeed,and initialpH(independentvariables)onmycelialbiomass pro-duction (dependent variable).18 _{In previous experiments,}

saccharoseand yeastextractwere selectedasthebest car-bon and nitrogen sources, respectively. SM was used with saccharoseandyeastextractatdifferentexperimental con-centrations. Submerged fermentation was conducted, and thebiomassquantifiedasdescribedpreviously.Allstatistical analyseswereperformedviaStatistic8.0software.

All results of the submerged fermentation experiments weresubjectedtovarianceanalysis(one-wayANOVA),andthe valueswerecomparedbyTukey’stestatp≤0.05.

Morphologyofthemycelialbiomass

Themorphologyofthemycelialbiomassproducedunderthe factorialdesignwas evaluated usingthe software Analysis FIVEOlympusand astereomicroscope(OlympusSZ61,Ltd., Tokyo,Japan).Thesampleswerefixedwithasolution com-posedof13mLof40%(v/v)formaldehyde,5mLofaceticacid, and200mLof50%(v/v)ethanol.19

Results

and

discussion

Effectofinoculumsize

Mycelialbiomassproductionvariedsignificantlydepending ontheinoculumsize(Fig.1).Thevolumeof6.0mLinduced higherbiomassproduction(5.00gL−1).Therefore,thisvolume wasusedforfurtherexperiments.

IninvestigationsonP.tuber-regium14_{andGrifolafrondosa,}20

theinoculumsizewithacellsuspensionvolumerangingfrom 0.5to12.0mL,or2to6%,hadahigherpositiveinfluenceon mycelialgrowthincomparisontothemediumvolumein sub-mergedfermentation.

Effectofcarbonandnitrogensources

AllcarbonsourcestestedpromotedP.albidusgrowth(Table1). However, saccharose (7.28gL−1), fructose (7.07gL−1), and maltose(6.99gL−1)were thecarbon sourcesthatpromoted the most considerable growth. Although the mushroom manifestedthe highestmycelialbiomassproductioninthe

e d c b a 0 1 2 3 4 5 6 7 8 6.0 4.0 2.0 1.0 0.5 M y celial biom ass (g .L –1 ) Inoculum volume (mL)

Fig.1–EffectofdifferentinoculumsizeonP.albidus

mycelialbiomassproduction.Meansfollowedbythesame letter(s)arenotsignificantlydifferent,asestablishedby Tukey’stest(p≤0.05).

treatmentwithsaccharose,theconsumptionofthissugar dur-ing the fermentationprocess wastwicelower than thatof fructose.Thisresultmighthavebeencausedbythenatureof thecarbonsource,becausesaccharoseisadisaccharidewhich isnecessaryforinvertaseexcretion,andafterdecomposition intoglucoseandfructose,itcanbeabsorbedbythefungus.27

Monosaccharides, suchasfructoseand glucose,are car-bon sources that stimulate Pleurotus growth in submerged fermentation.21,22 _{However, the preference for saccharose}

as a carbon source has also been reported for Antro-dia cinnamomea,23 _{Cordyceps militaris,}24 _{C. sinensis,}15 _{and C.}

jiangxiensis.25_{Consideringcostsandeaseofproduction,}

sac-charosecanbeconsideredamoresuitablesubstratecompared toothersyntheticsourcesavailableonthemarket.

In our study, saccharose was more efficiently con-verted into biomass (1.15gg−1) with a higher productivity (0.061gL−1h−1), whereas biomass and productivity were 0.86gg−1and0.059gL−1h−1,respectively,forfructose.These

Table1–Mycelialbiomass,conversionfactorofsubstratetobiomass(YX/S),yield(Yr/S)andproductivity(PX)ofP.albidus

underdifferentcarbonandnitrogensources.

Sources Mycelialbiomass(gL−1) YX/S(gg−1) Yr/S(gg−1) PX(gL−1h−1) FinalpH

Carbon Saccharose 7.28a _1.15a _0.36a _0.061a _5.19a Fructose 7.07a _0.86b _0.35a _0.059a _5.05b Lactose 6.23c _0.65d _0.31c _0.052c _5.21a Maltose 6.99a _0.79c _0.35a _0.058a _5.00b Glucose(basal) 6.56b _0.43e _0.33b _0.055b _5.06b Nitrogen Yeastextract 7.98a _0.42a _0.40a _0.066a _5.45a Tryptone 7.19b _0.39b _0.36b _0.060b _4.70c Ammoniumsulfate 1.39d _0.24c _0.07d _0.012d _3.33d Sodiumnitrate 0.79e _0.11d _0.04e _0.007e _4.62c Peptone(basal) 6.56c _0.43a _0.33c _0.055c _5.06b

valueswerehigherthanthosereportedforPleurotussajor-caju

(0.82gg−1and0.085gL−1h−1)inaliquidmediumcontaining aninitialconcentrationof10gL−1glucoseand0.59gg−1and 0.041gL−1h−1for10gL−1saccharose.17

Theaddition of sodium nitrate and ammonium sulfate in the culture media did not favor mycelial biomass pro-duction. Themaximum values of biomassformation were 0.79and1.39gL−1,respectively(Table1).Thesefindingsare inaccordance withthose obtained forC. militaris24 _{and G.}

frondosa.20_{Overall,itseemsthatinorganicnitrogendoesnot}

promotegrowthofseveralfungispecies,incontrasttoorganic sources.24,26

Deacon27 _{describes that as a result of ammonia}

metabolism,H+_{ionsarereleased,andthepHofthemedium}

isreduced,inhibitingthegrowthofsomemushroomspecies. This was alsoobserved when, atthe end of fermentation process,thepHofculturemediainwhichammoniumsulfate andsodiumnitratewereutilizedwasbelow4.6(Table1).

OurresultsindicatedthatYE(7.98gL−1)wasthenitrogen sourcethatstimulatedmostpronouncedlymycelialbiomass production,whichwasduetopresenceofseveralother nutri-ents,includingcarbonsources,growthfactors,andvitamins presentinYE.ThebiomassofP.albiduswashigherinthe cul-turemediumcontainingYE,andthevaluesobtainedforyield andproductivity were 0.40gg−1 and0.066gL−1h−1, respec-tively,whichweresignificantlyhigherwhencomparedwith theothernitrogensourcesevaluated.However,nostatistical differences(p≤0.05)were observedbetween the valuesfor yeastextractandcontrolconcerningthevaluesofthe con-versionfactorofsubstratetobiomass.

Thepresenceoftryptone(7.19gL−1)andpeptone(6.56gL1₎

inculturemediaalsofavoredbiomassproductionwith val-ues thatwere statisticallydifferent (p≤0.05) from those of theinorganic sourcesofnitrogen.Various organic nitrogen sourceshavebeenreportedassuitableformushroomsgrowth, includingmeatpeptone,polypeptone,yeastextract,and soy-beanconcentrates.20,23,28

Factorialdesign

Thevariablesandtheresultsobtainedfromtherunsofthe24

fullfactorialdesignarelistedinTable2.Themycelialbiomass productionrangedfrom3.92gL−1to9.81gL−1representedby runs3and12,respectively.

Thecontrastvalueswerecalculatedforeachofthe vari-ablesandtheirinteractionsfromtheexperimentsoffactorial design(Table3).Allvariableshadasubstantialinfluenceon mycelialbiomassproduction,and,intermsoftheirimpact, theycan be classified inthe following decreasing order of significance:saccharoseconcentration,agitationspeed,yeast extractconcentration,andpH.Forthefirstthreevariablesthe effectwaspositive,whichindicatedthattheincreaseofthis lowerleveltothehigherlevelfavoredbiomassproductionof

P.albidusinthefermentationprocess.ThepHwasalso signif-icantforthisresponse;however,thenegativeeffectshowed thatthereductionoftheinitialpHpromotedmorefavorable conditionsforproductionofmycelialbiomass.The interac-tionsofpHandagitationspeed,andsaccharoseconcentration andagitationspeedonthehigherlevel,alsofavoredP.albidus

growth.

Table2–Resultsofthefullfactorialdesign24_for

mycelialbiomassproductionbyP.albidus.

Runs Sca _YEcb _{pH As}c _{Mycelialbiomass(gL}−1₎

1 10.0 2.5 5.0 120 4.52 2 10.0 2.5 5.0 180 5.47 3 10.0 2.5 7.0 120 3.92 4 10.0 2.5 7.0 180 5.37 5 10.0 10.0 5.0 120 6.70 6 10.0 10.0 5.0 180 5.72 7 10.0 10.0 7.0 120 5.21 8 10.0 10.0 7.0 180 5.11 9 30.0 2.5 5.0 120 6.87 10 30.0 2.5 5.0 180 6.49 11 30.0 2.5 7.0 120 5.24 12 30.0 2.5 7.0 180 9.81 13 30.0 10.0 5.0 120 7.53 14 30.0 10.0 5.0 180 9.26 15 30.0 10.0 7.0 120 6.59 16 30.0 10.0 7.0 180 9.56 17d _{20 5.0 6.0 150 7.47} 18d _{20 5.0 6.0 150 7.34} 19d _{20 5.0 6.0 150 7.41} a _{Sc,saccharoseconcentration(gL}−1_). b _{YEc,yeastextractconcentration(gL}−1_). c _{As,agitationspeed(rpm).}

d _{Centralpoints.}

Thehighestbiomassproductionwas9.81gL−1,as deter-minedinrunnumber12withtheculturemediumformulated withsaccharose(30.0gL−1), yeastextract(2.5gL−1), pH7.0, and an agitation speed of 180rpm. An R-square value of 0.9341wasobtainedforthebiomass,indicatingthatthemodel explainedapproximately93%ofthevariabilitydata.

Park et al.11 _{evaluated the influence of different}

phys-icochemical parameters on the growth and production of polysaccharides by submerged fermentation in another mushroomspecies(C.militaris).Theirresultsindicatedthat

Table3–Contrastvaluescalculatedaccordingtofactorial designofP.albidusmycelialbiomassproduction.

Variables Contrasts

(1)Saccharoseconcentration 120.75±1.06+

(2)Yeastextractconcentration 49.90±1.06+

(3)pH −11.00±1.06+ (4)Agitationspeed 63.75±1.06+ Interaction1-2 6.64±1.06 Interaction1-3 24.03±1.06+ Interaction1-4 47.25±1.06+ Interaction2-3 −23.34±1.06+ Interaction2-4 −18.50±1.06+ Interaction3-4 47.26±1.06+ Interaction1-2-3 −5.90±1.06+ Interaction1-2-4 24.93±1.06+ Interaction1-3-4 30.14±1.06+ Interaction2-3-4 −20.93±1.06+

+ _{Statisticallysignificantvaluesata95%confidencelevel.}

Thestandarderrorsareestimatedfromthereplicaterunsatthe centralpoint.Theerrorisdescriptivearoundofthecontrast esti-mate,aftersymbol±.

Fig.2–Pelletmorphologyunderdifferentcultureconditions.(A)Run11,(B)Run5,(C)Run8,(D)Run9,(E)Run12and(F) Run14ofthefactorialdesign.

amongthecarbonsourcestested,saccharosealsoexerteda favorableeffectonmycelialgrowth.Thegrowthwas propor-tionaltotheincreaseoftheinitialconcentrationofthiscarbon source,rangingfrom 10gL−1to60gL−1 andexpressingthe maximumgrowthinthemediumcontaining60gL−1of sac-charose.

AccordingtoTangetal.,5_{theagitatedculturemedium}

pro-motedproperhomogenizationofcomponents,increasedthe oxygenation,andimprovedthemassandheattransfer.These conditionshad apositiveinfluenceon mushroommycelial growthbysubmergedfermentation.Nevertheless,extremely highagitationspeedsmay alsocause shearforcesthatcan damagethehyphae,causingchangesinthemycelium, vari-ationsingrowthrate,andinterferewithproductformation. Theagitationspeedof180rpminP.albiduscultureswasthat themostsuitableforthemycelialgrowthincomparisontothe othersspeedstested.Theseresultsdifferfromthoseobtained byKimetal.29_{whoevaluatedtheeffectofagitationspeedand}

aerationonthemycelialgrowthofGanodermaresinarum.The authorsreportedthatwhenagitationspeedincreasedfrom50 to250rpm,biomassproductionwasreducedbyapproximately 30%(from12.7gL−1to8.9gL−1).

TheuseofYEasanitrogensourceintheculturemedium toevaluatebiomassproductionbyG.frondosawasreported.20

Theauthorsevidencedthatthebiomassincreasedasthe con-centrationofthenitrogensourcewaselevatedintheculture medium;andtheyeastextractconcentrationof6gL−1was optimalforbiomassproduction.Anumber ofstudies have indicatedthatmushrooms,whengrownundertheconditions ofsubmergedfermentation,havepreferencefororganic nitro-gensources,suchasyeastextractandpeptoneratherthan fortheinorganic ones.30,31 _{Gbolagade etal.}32 _reportedthat

thispreferencemaybeexplainedbythecomplex combina-tionofaminoacidsandcarbohydratespresentintheseorganic compounds,resultingintheenhancedfungalgrowth.

FermentationmediumpHisanextremelyimportant vari-ableinthegrowthoffungi,asitaffectsthefunctionofthe

cellmembrane,thestructure,andcellularmorphology,aswell astheprocessesofuptakeofvariousnutrientsandproduct biosynthesis.27,33_{Inthisresearch,theresultsindicatedthat,in}

general,theuseoflowerinitialpHinculturemediumfavored

P.albidusgrowth.Attheendofthefermentationprocess,the pHremainedconstantintheculturemediawheretheinitial pHwas5.0.However,whenthefungusstarteditsgrowthat initialpH7.0,therewasareductiontopH5.0.Accordingto Papagianni,33_{culturemediumcompositionmayaffectthe}

ini-tialculturemediumpHcausingfluctuationsinthepHrange duringfungalgrowth.

Morphologicalobservationsofmyceliuminsubmerged

fermentation

Znidarsic and Pavko34 _{and Kim et al.}29 _{reported that the}

characteristicsofthemyceliumproducedbysubmerged fer-mentationareinfluencedbycultureconditions,suchasthe compositionandinitialpHofthefermentationmedium,the ageandsizeofinoculum,aerationrate,andagitationspeed.

Theformationofpelletswithdifferentsizesand morphol-ogywereobservedinallfermentationconditions.Thesepellet characteristicsweremoreevidentaftervariationinthe agi-tationspeed,followingthealterationsintheinitialpHofthe culturemedium.Whentheprocesswasperformedat120rpm, thepelletswerelargeandfewinnumbers,whereasat180rpm, theybecamesmallerinsizeandlargerinquantity.The varia-tioninthesizeofpelletsunderdifferentagitationconditions wasalsoreportedbyotherauthors.29_{Theyobservedthe}

pres-enceoflargepelletswhenGanodermaresinaceumwassubjected toanagitationspeedof50rpm,whereasundermore vigor-ousagitation(300rpm),pelletsbecamesmallattheendofthe fermentationprocess.

At120rpmandpH7.0,growthofelongatedandprotruding hyphae onthe surfaceofthepelletswasobserved(Fig.2a). Under fermentationconditionsofpH5.0,theextensionsof thesehyphaeexhibitedmorereducedlengthorwereabsent

(Fig.2bandd).InastudyperformedbyHwangetal.,35_the

authorsverifiedthatPhellinusbaumiigrowninaliquidmedium producedpellets withastarfish-like appearanceata more acidic pH. However, when the pH of the culture medium rangedfromneutraltoalkaline,pelletsbecamemorecompact, andnofreemyceliumwasavailable.

Inculturesperformedatahigheragitationspeed(180rpm), exceptforrunno.6,pelletswerepresent,and,ingeneral, elon-gatedhyphaewereobservedonthesurface.AtpH7.0(Fig.2c ande),hyphaearoundthepelletsweremorenumerousthan atpH5.0(Fig.2f).

Similar resultswere alsoobtained byParket al.,11 _who

reported that the pellets of C. militaris formed during the fermentationperiodincreasedinsizeindependentlyofthe agitation speed. Nonetheless, when the fermentation was conducted under low agitation speed (50rpm), the pellets becamelarge andfluffy, whereas atahighagitation speed (300rpm),theouterhairyregionsofthepelletswereremoved and,consequently,becamesmallerandchangedtoacircular shape.

Duringthe fermentationprocess,P. albidusbiomasswas observed to adhere strongly to the inside walls of the Erlenmeyer flasksin all growth conditions evaluated. This phenomenonwasalsoobservedinpreviousinvestigationson submergedfermentationofGanodermalucidum,inwhichthe authorsreportedbiomassadherenceduetothe polysaccha-ridesproduction.36

Whenestablishingarelationshipbetweentheproduction andbiomassmorphologyofP.albidus,highermycelialbiomass productionwasfoundwhenthepelletsweresmallinsizewith shorthyphae.

Conclusion

Theresultsobtainedinthisstudyelucidatedsomeimportant aspectsofthemorphologyandphysiologyofP.albidus.These findingscanbeconsideredpioneeringfortheproductionof mycelialbiomassofthismushroombysubmerged fermen-tation.Thecomponentsoftheculturemedia,includingthe concentrationandtypeofcarbonandnitrogensources,initial pH,inoculumvolume,andagitationspeedaremainfactors thatsignificantlyaffectbiomassproduction.The experimen-tal design was an effective tool for evaluating the culture factorsthatmostinfluencedthegrowthandmorphologyof themushroombiomass.Thisinformationmaybeusefulfor theproductionofP.albidusmycelialbiomassforhuman con-sumption.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

Acknowledgements

Theauthorsacknowledgethetechnicalandfinancialsupport grantedbytheCultureCollectionDPUAandCoordenac¸ãode Aperfeic¸oamentodePessoaldeNívelSuperior(Capes)/Brazil.

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