WEL COME

Submitted To : Dr, Lakshmipathi Department of Microbiology College of Sericulture Chintamani,

Submitted By :

Deepak T. N I Bsc ( agri ) ALC 3015 College of

Sericulture Chintamani .

Topic Topic : CULTURE : CULTURE MEDIA MEDIA

Bacteria have to be grown (cultured) Bacteria have to be grown (cultured) for them to be identified.for them to be identified.

By appropriate procedures they have By appropriate procedures they have to be grown separately (isolated) on to be grown separately (isolated) on culture media and obtained as pure culture media and obtained as pure for study.for study.

HistoryHistory The original media used by Louis The original media used by Louis

Pasteur – urine or meat brothPasteur – urine or meat brothLiquid medium – diffuse growthLiquid medium – diffuse growthSolid medium – discrete coloniesSolid medium – discrete colonies..

ColonyColony – macroscopically visible – macroscopically visible collection of millions of bacteria collection of millions of bacteria originating from a single originating from a single bacterial cell.bacterial cell.

Cooked cut potato by Robert Cooked cut potato by Robert Koch – earliest solid mediumKoch – earliest solid medium

Gelatin – not satisfactoryGelatin – not satisfactory- liquefy at 24- liquefy at 24ooCC

AgarAgarFrau HesseFrau HesseUsed for preparing solid mediumUsed for preparing solid mediumObtained from seaweeds.Obtained from seaweeds.No nutritive valueNo nutritive valueNot affected by the growth of the Not affected by the growth of the

bacteria.bacteria.Melts at 98Melts at 98ooC & sets at 42C & sets at 42ooCC2% agar is employed in solid medium 2% agar is employed in solid medium

Types of culture mediaTypes of culture media

I.I. Based on their consistency Based on their consistency a) solid mediuma) solid mediumb) liquid mediumb) liquid mediumc) semi solid mediumc) semi solid medium

II.II. Based on the constituents/ Based on the constituents/ ingredientsingredientsa) simple mediuma) simple mediumb) complex mediumb) complex mediumc) synthetic or defined mediumc) synthetic or defined mediumd) Special mediad) Special media

Special mediaSpecial mediaEnriched mediaEnriched mediaEnrichment mediaEnrichment mediaSelective mediaSelective mediaIndicator mediaIndicator mediaDifferential mediaDifferential mediaSugar mediaSugar mediaTransport mediaTransport media

III.III.Based on Oxygen Based on Oxygen requirementrequirement- Aerobic media- Aerobic media- Anaerobic media- Anaerobic media

Solid media Solid media – contains 2% agar– contains 2% agarColony morphology, pigmentation, Colony morphology, pigmentation,

hemolysis can be appreciated.hemolysis can be appreciated.Eg: Nutrient agar, Blood agarEg: Nutrient agar, Blood agar

Liquid media Liquid media – – no agar. no agar. For inoculum preparation, Blood For inoculum preparation, Blood

culture, for the isolation of pathogens culture, for the isolation of pathogens from a mixture.from a mixture.

Eg: Nutrient brothEg: Nutrient broth

Semi solid medium Semi solid medium – 0.5% agar. – 0.5% agar. Eg: Motility mediumEg: Motility medium

Complex mediaComplex mediaMedia other than basal media.Media other than basal media.They have added ingredients.They have added ingredients.Provide special nutrients Provide special nutrients

Synthetic or defined mediaSynthetic or defined mediaMedia prepared from pure Media prepared from pure chemical substances and its chemical substances and its exact composition is knownexact composition is known

Eg: peptone water – 1% Eg: peptone water – 1% peptone + 0.5% NaCl in waterpeptone + 0.5% NaCl in water

Enriched mediaEnriched media

Substances like blood, serum, egg Substances like blood, serum, egg are added to the basal medium.are added to the basal medium.

Used to grow bacteria that are Used to grow bacteria that are exacting in their nutritional needs.exacting in their nutritional needs.

Eg: Blood agar, Chocolate agarEg: Blood agar, Chocolate agar

Blood agar Chocolate agar

Selective mediaSelective mediaThe inhibitory substance is added to a The inhibitory substance is added to a

solid media.solid media.Eg:Eg:Mac Conkey’s medium Mac Conkey’s medium for gram for gram

negative bacterianegative bacteriaTCBS TCBS – for V.cholerae– for V.choleraeLJ medium LJ medium – M.tuberculosis– M.tuberculosisWilson and Blair medium Wilson and Blair medium – S.typhi– S.typhiPotassium tellurite medium Potassium tellurite medium – –

Diphtheria bacilliDiphtheria bacilli

TCBSMac Conkey’s medium

Potassium Tellurite media LJ media

Indicator mediaIndicator mediaThese media contain an indicator These media contain an indicator

which changes its colour when a which changes its colour when a bacterium grows in them.bacterium grows in them.

Eg: Eg: Blood agarBlood agarMac Conkey’s mediumMac Conkey’s mediumChristensen’s urease mediumChristensen’s urease medium

Urease mediumUrease medium

Differential mediaDifferential mediaA media which has substances A media which has substances

incorporated in it enabling it to incorporated in it enabling it to distinguish between bacteria.distinguish between bacteria.

Eg: Mac Conkey’s mediumEg: Mac Conkey’s mediumPPeptoneeptoneLLactoseactoseAAgargarNNeutral redeutral redTTaurocholate aurocholate

Distinguish between lactose Distinguish between lactose fermenters & non lactose fermenters.fermenters & non lactose fermenters.

Lactose fermenters – Lactose fermenters – PinkPink colonies coloniesNon lactose fermenters – colourless Non lactose fermenters – colourless

coloniescolonies

Sugar mediaSugar media Media containing any fermentable Media containing any fermentable

substance.substance.Eg: glucose, arabinose, lactose, Eg: glucose, arabinose, lactose,

starch etc.starch etc.Media consists of 1% of the sugar in Media consists of 1% of the sugar in

peptone water.peptone water.Contain a small tube (Durham’s Contain a small tube (Durham’s

tube) for the detection of gas by the tube) for the detection of gas by the

bacteriabacteria..

Transport mediaTransport mediaMedia used for transporting Media used for transporting

the samples.the samples.Delicate organisms may not Delicate organisms may not

survive the time taken for survive the time taken for transporting the specimen transporting the specimen without a transport media.without a transport media.

Eg: Eg: Stuart’s medium Stuart’s medium – non – non nutrient soft agar gel nutrient soft agar gel containing a reducing agentcontaining a reducing agent

Buffered glycerol saline Buffered glycerol saline – – enteric bacilli enteric bacilli

Anaerobic mediaAnaerobic mediaThese media are used to grow These media are used to grow

anaerobic organisms.anaerobic organisms.Eg: Robertson’s cooked meat Eg: Robertson’s cooked meat

medium, Thioglycolate mediummedium, Thioglycolate medium..

THANK YOU