MCB6424 PROBIOTICS EXAM 1- QUESTIONS
WITH CORRECT ANSWERS 2025
Bulgarianvyogurtvcontainedvwhichvspecies?v-vCORRECTvANSWERv-
lactobacillusvbulgaricusvandvstreptococcusvthermophilus
Tissierv-v1899v-vCORRECTvANSWERv-
identifiedvbifidobacteriavandvpromotedvtherapeuticvusevforvtreatingvinfantvdiarrhea.
Metchnikoffv-v1907v-vCORRECTvANSWERv-
Proposedvthatvthevacidvproducingvbacteriavinvfermentedvmilkvproductsvcouldvpreventv"fouling"vinvthevlarge
vintestinevandvleadvtovavlongervlife.vHevsuggestedvthatvthevbacteriav(lactobacillusvandvstrep)vinvyogurtvsuppr
essvthevbadvfermentationvinvintestinalvfloravandvconsumptionvofvyogurtvplaysvavrolevinvmaintainingvhealth.
1930sv-vMinoruvShirotav-vCORRECTvANSWERv-developedvavfermentedvmilkvproductvcalledvYakult
1935v-vstartedvmarketingvyakultvasvavprobioticvyogurt-
likevproductvmadevbyvfermentingvavmixturevofvskimmedvmilkvwithvavstrainvofvLactobacillusvcaseivshirota.
1965v-vLillyvandvStillwellv-vCORRECTvANSWERv-probioticsvtermvcoinedv-
v"substancesvsecretedvbyvonevmicroorganismvthatvstimulatevthevgrowthvofvanother"
CurrentvDefinitionvofvProbiotics:v-vCORRECTvANSWERv-
"Livevmicroorganisms,vwhichvwhenvadministeredvinvadequatevamountsvconfervavhealthvbenefitvonvthevhost
"
Whovcoinedvthevcurrentvdefinitionvofvprobiotics?v-vCORRECTvANSWERv-
Definedvinv2002vbyvFoodvandvAgriculturalvOrganizationvofvthevUnitedvNationsvandvWHO
Guidelinesvforvavproductvtovbevcalledv"probiotic"v-vCORRECTvANSWERv-publishedvbyvFAO/WHOvinv2002
strainedvbevdesignedvindividually
speciatedvappropriatelyv-vgoodvmolecularvtoolsvtovidentifyvwhatvisvpresentvinvthatvproductv-
vdifferentvstrainsvofvavspeciesvofvLactobacillusvcaseivwillvnotvallvhavevthevsameveffectvonvthevhostv
,retainvavviablevcountvatvthevendvofvtheirvshelfvlifevinvthevdesignatedvproductvformulationvthatvconfersvavpro
venvclinicalvend-point
True/FalsevThevprobioticvdefinitionvrequiresvthatvthevefficacyvandvsafetyvofvprobioticsvbevverifiedv-
vCORRECTvANSWERv-True
assessmentvofvthisvconstitutesvanvimportantvpartvofvtheirvcharacterizationvforvhumanvusev-
vifvtheyvmakevavclaimvthatvsomethingvwillvreducevavheadache,vtheyvMUSTvhavevclinicalvtrialsvthatvbackvupvth
atvclaimv(andvnotvcausevothervsideveffects)
Strainsvmustvgovthroughvrigorousvclinicalvtrialsv-vitvtakesvyears.vWhatvarevthevphasesvofvtesting?v-
vCORRECTvANSWERv-phasev1v-vanimalvtesting
phasev2v-vdoublevblindvhumanvtrialsv
Thenvit'svavprobioticvfoodv(labeling,vetc.)
phasev3v-veffectivenessv-vonlyvnecessaryvifvyou'revtryingvtovusevforvdiseasevprevention
Mostvcommonvgeneravofvprobioticvorganismsv-vCORRECTvANSWERv-
Lactobacillus,vStreptococcus,vBifidobacterium
lessvcommonv-vEnterococcus,vBacillus,vSaccharomyces,vPropionibacterium
GeneralvSelectionvCriteriavforvProbioticsv-vCORRECTvANSWERv-Non-pathogenicvandvnon-toxicv
Ablevtovsurvivevthevpassagevthroughvthevdigestivevsystem
Ablevtovattachvtovthevintestinalvepitheliavandvcolonize
Ablevtovmaintainvgoodvviability
Ablevtovutilizevthevnutrientsvandvsubstratesvinvavnormalvdiet
Capablevofvexertingvavbeneficialveffectvonvthevhost
LacticvAcidvBacteria:vGeneralvDescriptionv-vCORRECTvANSWERv-Domain:vBacteria
Phylum:vFirmicutes
Class:vBacilli
, Order:vLactobacillalesv
Gram-positive
Non-sporevformer
Non-respiringvcoccivorvbacilliv
Strictlyvfermentativevwithvlacticvacidvasvthevmajorvend-product
Fastidiousv(needvmanyvnutrientsvtovgrow)
Acidvtolerant
Aerococcusv-vCORRECTvANSWERv-meatvcuringvbrines
Carnobacteriumv-vCORRECTvANSWERv-
previouslyvgroupvDvstreptococci;vintestinal;vopportunisticvpathogen;vpossiblevprobiotic
Lactobacillusv-vCORRECTvANSWERv-widespreadvintestinalvandvextraintestinalvorganisms;vfoodvfermenter
Lactococcusv-vCORRECTvANSWERv-
PreviouslyvgroupvNv(lactic)vstreptococci;vstartervculturesvforvmostvcheeses
Leuconostocv-vCORRECTvANSWERv-meatvpreservationvandvspoilage;vsugarvspoilage
Oenococcusv-vCORRECTvANSWERv-malolacticvfermentationvofvwine
Pediococcusv-vCORRECTvANSWERv-Traditionalvgenusvinvolvedvinvmeatvfermentation;vbeervspoilage
Streptococcusv-vCORRECTvANSWERv-
MainlyvpathogensvexceptvforvS.vthermophilusvthatvisvusedvinvcheesevandvyogurtvmaking
Tetragenococcusv-vCORRECTvANSWERv-previouslyvPediococcus;vusedvinvproductionvofvsoyvsauce
WITH CORRECT ANSWERS 2025
Bulgarianvyogurtvcontainedvwhichvspecies?v-vCORRECTvANSWERv-
lactobacillusvbulgaricusvandvstreptococcusvthermophilus
Tissierv-v1899v-vCORRECTvANSWERv-
identifiedvbifidobacteriavandvpromotedvtherapeuticvusevforvtreatingvinfantvdiarrhea.
Metchnikoffv-v1907v-vCORRECTvANSWERv-
Proposedvthatvthevacidvproducingvbacteriavinvfermentedvmilkvproductsvcouldvpreventv"fouling"vinvthevlarge
vintestinevandvleadvtovavlongervlife.vHevsuggestedvthatvthevbacteriav(lactobacillusvandvstrep)vinvyogurtvsuppr
essvthevbadvfermentationvinvintestinalvfloravandvconsumptionvofvyogurtvplaysvavrolevinvmaintainingvhealth.
1930sv-vMinoruvShirotav-vCORRECTvANSWERv-developedvavfermentedvmilkvproductvcalledvYakult
1935v-vstartedvmarketingvyakultvasvavprobioticvyogurt-
likevproductvmadevbyvfermentingvavmixturevofvskimmedvmilkvwithvavstrainvofvLactobacillusvcaseivshirota.
1965v-vLillyvandvStillwellv-vCORRECTvANSWERv-probioticsvtermvcoinedv-
v"substancesvsecretedvbyvonevmicroorganismvthatvstimulatevthevgrowthvofvanother"
CurrentvDefinitionvofvProbiotics:v-vCORRECTvANSWERv-
"Livevmicroorganisms,vwhichvwhenvadministeredvinvadequatevamountsvconfervavhealthvbenefitvonvthevhost
"
Whovcoinedvthevcurrentvdefinitionvofvprobiotics?v-vCORRECTvANSWERv-
Definedvinv2002vbyvFoodvandvAgriculturalvOrganizationvofvthevUnitedvNationsvandvWHO
Guidelinesvforvavproductvtovbevcalledv"probiotic"v-vCORRECTvANSWERv-publishedvbyvFAO/WHOvinv2002
strainedvbevdesignedvindividually
speciatedvappropriatelyv-vgoodvmolecularvtoolsvtovidentifyvwhatvisvpresentvinvthatvproductv-
vdifferentvstrainsvofvavspeciesvofvLactobacillusvcaseivwillvnotvallvhavevthevsameveffectvonvthevhostv
,retainvavviablevcountvatvthevendvofvtheirvshelfvlifevinvthevdesignatedvproductvformulationvthatvconfersvavpro
venvclinicalvend-point
True/FalsevThevprobioticvdefinitionvrequiresvthatvthevefficacyvandvsafetyvofvprobioticsvbevverifiedv-
vCORRECTvANSWERv-True
assessmentvofvthisvconstitutesvanvimportantvpartvofvtheirvcharacterizationvforvhumanvusev-
vifvtheyvmakevavclaimvthatvsomethingvwillvreducevavheadache,vtheyvMUSTvhavevclinicalvtrialsvthatvbackvupvth
atvclaimv(andvnotvcausevothervsideveffects)
Strainsvmustvgovthroughvrigorousvclinicalvtrialsv-vitvtakesvyears.vWhatvarevthevphasesvofvtesting?v-
vCORRECTvANSWERv-phasev1v-vanimalvtesting
phasev2v-vdoublevblindvhumanvtrialsv
Thenvit'svavprobioticvfoodv(labeling,vetc.)
phasev3v-veffectivenessv-vonlyvnecessaryvifvyou'revtryingvtovusevforvdiseasevprevention
Mostvcommonvgeneravofvprobioticvorganismsv-vCORRECTvANSWERv-
Lactobacillus,vStreptococcus,vBifidobacterium
lessvcommonv-vEnterococcus,vBacillus,vSaccharomyces,vPropionibacterium
GeneralvSelectionvCriteriavforvProbioticsv-vCORRECTvANSWERv-Non-pathogenicvandvnon-toxicv
Ablevtovsurvivevthevpassagevthroughvthevdigestivevsystem
Ablevtovattachvtovthevintestinalvepitheliavandvcolonize
Ablevtovmaintainvgoodvviability
Ablevtovutilizevthevnutrientsvandvsubstratesvinvavnormalvdiet
Capablevofvexertingvavbeneficialveffectvonvthevhost
LacticvAcidvBacteria:vGeneralvDescriptionv-vCORRECTvANSWERv-Domain:vBacteria
Phylum:vFirmicutes
Class:vBacilli
, Order:vLactobacillalesv
Gram-positive
Non-sporevformer
Non-respiringvcoccivorvbacilliv
Strictlyvfermentativevwithvlacticvacidvasvthevmajorvend-product
Fastidiousv(needvmanyvnutrientsvtovgrow)
Acidvtolerant
Aerococcusv-vCORRECTvANSWERv-meatvcuringvbrines
Carnobacteriumv-vCORRECTvANSWERv-
previouslyvgroupvDvstreptococci;vintestinal;vopportunisticvpathogen;vpossiblevprobiotic
Lactobacillusv-vCORRECTvANSWERv-widespreadvintestinalvandvextraintestinalvorganisms;vfoodvfermenter
Lactococcusv-vCORRECTvANSWERv-
PreviouslyvgroupvNv(lactic)vstreptococci;vstartervculturesvforvmostvcheeses
Leuconostocv-vCORRECTvANSWERv-meatvpreservationvandvspoilage;vsugarvspoilage
Oenococcusv-vCORRECTvANSWERv-malolacticvfermentationvofvwine
Pediococcusv-vCORRECTvANSWERv-Traditionalvgenusvinvolvedvinvmeatvfermentation;vbeervspoilage
Streptococcusv-vCORRECTvANSWERv-
MainlyvpathogensvexceptvforvS.vthermophilusvthatvisvusedvinvcheesevandvyogurtvmaking
Tetragenococcusv-vCORRECTvANSWERv-previouslyvPediococcus;vusedvinvproductionvofvsoyvsauce
