CULTURE & CULTURE MEDIA

Culture and culture media

studying microorganisms relies on the microbe's ability to grow in/on culture medium and survive outside hosts

cultures

growth of microorganisms in special media used to provide nutrition to the microbes(culture medium)

culture medium

liquid, semi-solid, solid preparation used to observe growth, to transport and to store culture

culture medium made up of _?

agar

types of cultures

pure, mixed, stock

pure culture

one genus, usually made from mixed culture

mixed culture

more than one species

stock culture

for academic, industrial use

Classification of culture medium

According to consistency, composition, to how medium is dispensed, to use

Classification of Culture medium(according to consistency)

liquid, semi-solid, solid medium

Liquid medium

Thioglycollate, BHI, TSB

Thioglycollate

Liquid media used for anaerobic bacteria, test for Oxygen requirement

BHI

Brain Heart Infusion Agar

Brain Heart Infusion Agar

for cultivating a wide variety of organism (bacteria, yeast, fungi etc)

TSB

Tryptic Soybroth

Tryptic Soybroth

liquid enrichment medium, used in qualitative enrichment, and for microorganisms that live in aerobic conditions

semi-solid medium agar percentage

0.5 to 1%

Semi-solid medium

Sulfide Indole Motility (SIM) medium

SIM medium

tests organims' reaction to sulfur reduction, indole production, motility

Solid Medium Agar Concentration

2-3%

Solid medium

TSI, Mac Conkey, Chocolate agar

TSI

Triple Sugar Iron

According to composition(classification of culture medium

Synthetic/Defined Medium, Non-synthetic/Complex, Tissue culture

synthetic or defined media

Exact composition is known; for research

Non-synthetic (complex) media

Contains chemically undefined components(peptones, yeast & meat extracts)
ex. nutrient broth, TSB, Mac Conkey Agar

tissue culture

used to isolate obligate intracellular bacteria(Chlamydia, Rickttsia)
ex. W 128, HELA 229 cells, Mc Coy cells

According to how medium is dispensed(classification of culture medium)

plated medium, tube medium(butt, slant, slant with butt)

According to Use(classification of Culture media)

simple media, enrichment media, enriched media, differential media, selective media, special media

simple media

used routinely to grow and isolate microbes without added supplements

Simple media examples

TSB, Nutrient Agar(NA), broth

Enrichment media

encourages growth of certain desired microbe

Enrichment media example

alkaline peptone water, selenite F, BCYE, TMA

BCYE

Buffered charcoal yeast extract

TMA

thayer martin agar

Enriched media

with added supplements (commonly sheep's blood) necessary for growth of organism, solid type media

Enriched Media

BAP, CAP, CAP with horse blood

BAP

blood agar plate - red bcs of sheep's blood

CAP

Chocolate Agar Plate - darker in color bcs of blood heated

CAP with horse blood

prepared with horse blood

Differential media

allows growth of several types of microbes and displays visible differences among those microbes
-differentiates different bacteria from one another

differential media example

MacConkey, BAP, EMB, HE

EMB

Eosin Methylene Blue

HE

hektoen agar

selective media

with inhibitory substance or antibiotic that stop other organisms while promoting desired organism

selective media example

HE agar, mac conkey, bismuth sulfide agar, XLD, MSA

XLD

Xylose Lysine Deoxycholate

MSA(Mannitol Salt Agar)

with 7.5 salt

Gentamicin sugar

streptococci

Bacitracin Chocolate Agar

Haemophilus

BAP with Ampicillin

Aeromonas

PEA

gram + cocci

Columbia CNA agar with blood

gram + bacteria

GN Broth (Gram Negative Broth)

salmonella spp. & shigella spp

TMA(Thayer Martin Agar)

n. gonorrheae

Special medium

isolate specific type of bacteria
ex. LJ and TCBS

inhibitory substances(Crystal/gentian violet)

basic fuchsin, bile salt

inhibitory substances(Potassium tellurite)

sodium azide

Alcohol(inhibitory subs)

chloral hydrate

LJ medium

Lowenstein-Jensen
Selective
Isolation of Mycobacteria

TCBS

thiosulfate citrate bile salt sucrose

ways to facilitate anaerobic cultivation

- use special culture medium with thioglycollate & cysteine
- boil culture medium to remove Oxygen
- use anaerobic chamber system with vacuum pump & nitrogen gas to remove oxygen
- use gas pak jay
- use plastic bag/pouch with calcium carbonate & catalyst for small volume

bacterial growth curve

lag, log, stationary, death

generation

doubling of a cell population

generation time

the time it takes for a population to double

Lag phase

no cell division & no abrupt cell population increase occurs while bacteria adapt to their new environment

log phase

The period of exponential growth and division of bacterial population.
-period when biochemical testing and are sensitive to antimicrobial agents
(logarithmic)

stationary phase

period of equilibrium; microbial deaths balance production of new cells
-metabollic activities slow down with limited nutrients
-dead debris accumulate

death phase

cessation of bacterial growth
-cell death exceeds number of living organisms

reproduction of bacteria

transverse binary fission

transverse binary fission

Most common asexual reproductive process whereby single cell divides into two daughter cells after developing a transverse cell wall

Do all bacteria have the same regeneration time?

no