Surface and submerged fermentation

This PPt deals about types of fermentations such as surface and submerged fermentations principle, methods, applications, advantages and disadvantages

1. SURFACE AND SUBMERGED
FERMENTATION
K.Sudha Rameshwari, M.Sc., M.Phil., PGDBI., D.Litt.
V.V.Vanniaperumal College for women,
Virudhunagar

2. FERMENTATION
•Fermentationisthetechniqueofbiologicalconversionof
complexsubstratesintosimplecompoundsbyvarious
microorganismssuchasbacteriaandfungi.
•Fermentationreferstothemetabolicprocessbywhich
organicmolecules(normallyglucose)areconvertedinto
acids,gases,oralcoholintheabsenceofoxygenorany
electrontransportchain.
•Fermentationpathwaysregeneratethecoenzyme
nicotinamideadeninedinucleotide(NAD
+
),whichisusedin
glycolysistoreleaseenergyintheformofadenosine
triphosphate(ATP).
•Fermentationonlyyieldsanetof2ATPperglucose
molecule(throughglycolysis),whileaerobicrespiration
yieldsasmanyas32moleculesofATPperglucosemolecule
withtheaidoftheelectrontransportchain.

3. Function of Fermentation
•Inthecourseofthismetabolicbreakdown,theyalso
releaseseveraladditionalcompoundsapartfromthe
usualproductsoffermentation,suchascarbondioxide
andalcohol.Theseadditionalcompoundsarecalled
secondarymetabolites.
•Secondarymetabolitesrangefromseveralantibiotics
topeptides,enzymesandgrowthfactors.
•ThemainfunctionoffermentationistoconvertNADH
backintothecoenzymeNAD
+
sothatitcanbeused
againforglycolysis.
•Duringfermentation,anorganicelectronacceptor
(suchaspyruvateoracetaldehyde)reactswithNADH
toformNAD
+
,generatingproductssuchascarbon
dioxideandethanol(ethanolfermentation)orlactate
(lacticacidfermentation)intheprocess.

4. •Fermentationsystemsmaybe
•liquid,alsoknownassubmerged
•solidstate,alsoknownassurface.
•ThedevelopmentoftechniquessuchasSolid
StateFermentation(SSF)andSubmerged
Fermentation(SmF)hasleadtoindustrial-
levelproductionofbioactivecompounds.
•Mostfermentorsusedinindustryareofthe
submergedtype,becausethesubmerged
fermentorsavesspaceandismoreamenable
toengineeringcontrolanddesign.

5. Submerged Liquid Fermentations
•Submergedliquidfermentationsaretraditionallyused
fortheproductionofmicrobiallyderivedenzymes.
•Submergedfermentationinvolvessubmersionofthe
microorganisminanaqueoussolutioncontainingall
thenutrientsneededforgrowth.
•Fermentationtakesplaceinlargevessels(fermenter)
withvolumesofupto1,000cubicmeters.
•Thefermentationmediasterilizesnutrientsbasedon
renewablerawmaterialslikemaize,sugarsandsoya.
•Mostindustrialenzymesaresecretedby
microorganismsintothefermentationmediuminorder
tobreakdownthecarbonandnitrogensources.
•Batch-fedandcontinuousfermentationprocessesare
common

7. •Submergedfermentationisamethodof
manufacturingbiomoleculesinwhich
enzymesandotherreactivecompounds
aresubmergedinaliquidsuchasalcohol,oil
oranutrientbroth.
•SubmergedFermentation(SmF)/Liquid
Fermentation(LF)SmFutilizesfree-flowing
liquidsubstrates,suchasmolassesandbroths.
•Theprocessisusedforavarietyofpurposes,
mostlyinindustrialmanufacturing.

8. Principle of Submerged Fermentation
•Submergedfermentationinvolvesthegrowthofthe
microorganismasasuspensioninaliquidmediumin
whichvariousnutrientsareeitherdissolvedor
suspendedasparticulatesolidsinmanycommercial
media.
•Submergedfermentationisaprocessinvolvingthe
developmentofmicroorganismsinaliquidbroth.
•Thisliquidbrothcontainsnutrientsanditresultsin
theproductionofindustrialenzymes,antibioticsor
otherproducts.
•Theprocessinvolvestakingaspecificmicroorganism
suchasfungiandplacingitinasmallclosedflask
containingtherichnutrientbroth.

9. Principle of Submerged Fermentation
•Ahighvolumeofoxygenisalsorequiredfor
theprocess.Theproductionofenzymes
thenoccurswhenthemicroorganisms
interactwiththenutrientsonthebroth
resultinginthembeingbrokendown.
•Thebioactivecompoundsaresecretedinto
thefermentationbroth.

10. Methods of Carrying Out Submerged
Fermentation
•Inthebatch-fedprocess,sterilisednutrientsare
addedtothefermenterduringthegrowthofthe
biomass.
•Inthecontinuousprocess,sterilisedliquid
nutrientsarefedintothefermenteratthesame
flowrateasthefermentationbrothleavingthe
system.
•Inordertomaintainasuccessfulfermentation,
certainParametersliketemperature,pH,oxygen
consumptionandcarbondioxideformationare
measuredandcontrolled.

11. •Nextinharvestingenzymesfromthefermentation
mediumonemustremoveinsolubleproducts,e.g.
microbialcells.
•Thisisnormallydonebycentrifugation.
•Asmostindustrialenzymesareextracellular(secreted
bycellsintotheexternalenvironment),theyremainin
thefermentedbrothafterthebiomasshasbeen
removed.
•Theenzymesintheremainingbrotharethen
concentratedbyevaporation,membranefiltrationor
crystallizationdependingontheirintendedapplication.
•Ifpureenzymepreparationsarerequired,theyare
usuallyisolatedbygelorionexchange
chromatography.

12. •Several types of submerged type of
fermentors are known and they may be
grouped in several ways:
shape or configuration,
whether aerated or anaerobic and
whether they are batch or continuous.
•The most commonly used type of fermentor is
the Aerated Stirred Tank Batch Fermentor.

13. Applications of Submerged
Fermentation
•SmFis primarily used in the
extraction of secondary metabolites
that need to be used in liquid form.
•Submerged liquid fermentations are
traditionally used for the production
of microbially derived enzymes.

14. Advantagesof Submerged
Fermentation
•Submergedfermentationtechnologyhasthe
advantagesofshortperiod,lowcostandhighyield.
•Purificationofproductsiseasier.
•Inliquidculturethecontrolofthefermentationis
simplerandconsequentlysignificantreductionsin
fermentationtimescanbeachieved.
•Inthesameway,theuseofsubmergedculturecan
benefittheproductionofmanysecondarymetabolites
anddecreaseproductioncostsbyreducing
thelabourinvolvedinsolid-statemethods.

15. Limitationsof Submerged
Fermentation[SmF]
•Inrecentyears,manyresearchershave
demonstratedthatSSFhasalargeimpacton
productivity,leadingtohigheryieldsand
improvedproductcharacteristicscompared
toSmF
•Lowvolumetricproductivity
•Relativelylowerconcentrationoftheproducts
•Moreeffluentgeneration
•Complexfermentationequipments

16. Surface Fermentation
•Inthesurfacetechniques,themicroorganismsare
cultivatedonthesurfaceofaliquidorsolid
substrate.
•Thesetechniquesareverycomplicatedandrarely
usedinindustry.
•A.nigerformsamyceliumlayerontheliquid
surfaceofthealuminumorstainlesssteeltrays.
•Thesetraysarestackedinfermentationrooms
suppliedwithfilteredairwhichservesbothto
supplyoxygenandtocontrolthetemperatureof
fermentation.
•Surfacefermentationiseasytocontrolandto
implement.

17. Surface Fermentation
•Itneedsnoaerationoragitationofthefermentation
broth,soitneedsnoinstrumentationforaerationand
agitation.
•Theseparationofcitricacidfromthemyceliumis
easybecausethemicroorganismisnotdispersinginto
themedium.
•Onlythetemperatureandhumidityofthe
fermentationchamberneedcontrolling.
•Withsurfacefermentation,thefermentationbrothis
concentratedduetoahighevaporationrateduring
fermentation.
•Thus,expensesandlossesduringrecoveryand
purificationarelow.

18. •Theoldestandarelativelysimplemethodfor
productionofcomplexflavourextractsisthe
fermentationofflavourrawmaterialsbybacteria
andmoulds(aspergillus,mucor)onsolidnutrient
media.
•Themediaisplacedinsimplethermostaticboxes
onbaking-traylikeplatestowhichthemicro-
organismsareinoculated.
•ThistechniquewhichhasoriginatedinJapanfor
theproductionofKoijiseasoningsisstillused
todayfortheproductionofsoysaucemadefrom
rough-groundcerealsandsoybeanswhichare
inoculatedwithspecialmoulds.

19. •Afterincubatingthenutrientmediaforseveral
days,itisfinallyextractedwithwatertoisolate
thefermentedproductscontainedinthemedia.
•FormanyyearstheKoijitechniquewasalsothe
preferredmethodfortheproductionofenzymes
whicharesecretedbybacteriaandmouldsinto
theextracellularenvironment(thenutrient
media).
•Anotherexampleforatraditionalsurface
fermentationprocessisvinegarproductionby
aceticacidbacteriagrownonthesurfaceofwood
chips.

20. Disadvantages ofsurface fermentation
Buildinginvestmentcostsarehigh.
Personnelexpensesarehighindeveloped
industrialcountrieswithextremelyhigh
wages.
Fermentationtimeislongandtherefore
productivityislow.

21. Submerged fermentation is favored over
surface fermentation
•Lower total investment costs;
•Improved process control;
•Reduced fermentation time;
•Reduced floor space requirements;
•Lower labour costs;
•Simpler operations; and
•Easier maintenance of aseptic conditions on
an industrial scale.

22. Submerged fermentation has some disadvantages
compared to surface fermentation
•expenses for equipment are higher;
•consumption of electrical energy is higher;
•the process is very sensitive to short
interruptions
or
•breakdowns in aeration and vulnerable to
infections, which result not only in losses
of yield, but also in a total breakdown of
respective batches

23. REFERENCES
•http://ecoursesonline.iasri.res.in/mod/page/view.php?id=5
150
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1952): Chemist, biotechnologist, and statesman. Journal of
chemical education, 71(3), 209.
•Chojnacka, K. (2006). Fermentation products. Chemical
engineering and chemical process technology, 12.
•Ganguly, Subha. Chemical aspects of fermentation
technology in food processing industries. Research Journal
of Chemical and Environmental Sciences1.1 (2013): 42-43.
•https://microbenotes.com/submerged-fermentation/
•https://www.barnardhealth.us/flavouring-substances/
surface-fermentation.html