UNIT 2: CULTURE MEDIA, INOCULATION, AND INCUBATION TECHNIQUES

increase in cell number through binary fission

cell simply spilts into two cells producing two identical cells

time required for a cell to divide, and its population to double

cells form an initial outgrowth that enlarges its size until it approaches that of a parent cell, and then it separates

fungi that undergoes budding

microbes that grow and multiply or on a culture medium

a group of descendants of an original cell

aka axenic; contains a single microbial species

physical requirments for growth

cold loving

sensitive (dies) to temperatures over 20 C

optimum growth at 15C or below

optimum growth at 20 to 30 degrees celcius

a bacteria that is both a psycrophiles and psychrotrophs

bacteria that causes food poisoning

bacteria that still reproduce in low temperature

main difference in psychrophiles and psychrotrophs

optimum growth at 25 to 40 degrees

most common type of infectious microbes and is clinically significant due to its ability to cause disease

TRUE OR FALSE: listeria will die at a temperature of 25 to 40 degrees celcius

moderate temperature loving

heat loving

optimum growth at 50 to 60 degrees celcius

grow at 80 degrees celcius or higher

living near volcano and hot spring

grow at very low ph (0.1 to 5.4)

bacteria that is an acidophiles

resist growth of microbes in vagina; produce lactic acid

TRUE OR FALSE: some microbes are hostile n acidic environment

grow at pH 5.4 to 8.5

clinically significant because it matches the pH range of humans

grow at high pH (7 to 12)

example of a bacteria that is alkaliphiles

grows in GIT(colon) of humans becuase of its basic nature

TRUE OR FALSE: fungi can thrive in acidic and high salt concentration environment

"extreme halophiles" that require very high salt concentration that ranges from 20 to 30%

do not require high salt concentration for growth

they do not die and tolerate 2-15% salt concentration

chemical requirements for growth

other chemical requirments for growth

organisms which derive energy from organic carbon sources

may need to consume other living organism to live

organisms which use inorganic energy sources to synthesize organic compounds (no enzymes)

primary carbon source is carbon dioxide

make up 14% of the dry cell weight

sources are proteins, ammonium, nitrogen gas, nitrates

used to form proteins and some vitamins

sources are proteins, hydrogen sulfide, sulfates

used to form DNA, RNA, ATP, and phospholipids

sources inorganic phosphate salts, buffers

growth requirement for aerobic microorganisms

require oxygen to live (without it it dies)
eg: mycobacterium tuberculosis

can use oxygen, but can growin its absence; they have detoxify enzymes
eg: escherichia coli

can't use oxygen, and are harmed by the presence of toxic forms of oxygen. does not have detoxify enzymes
eg: clostridium tetani

can't use oxygen, but can grow in its absence
tolerates presenc of oxygen
have detoxify enzymes
eg: streptococcus pneumoniae

require oxygen at low concentrations
hav detoxify enzymes
eg: helicobacter pylori

oxygen in anaerobes

oxygen in aerobes

enzymes required to neutralize fom of o2

convertes superoxide to oxygen and hydorgen peroxide

chemical equation of reaction of superoxide dismutase

converts hydrogen peroxide to water an doxygen

chemical reaction of catalase

breaks down hydrogen peroxide

chemical reaction of peroxidase

CO2 loving

require increases concentration of CO2 and lower evels of O2

bacterial growth curve

no increase in number of living bacterial cells ( microbes are adjusting)

exponntial increase in number of living bacterial cells

no, of cells dividing is greater than no. of cells dying

plateau in number of living bacterial cells; rate of cell division and death roughly equal (exhaustion of resources)

exponential decrease in number of living bacterial cells

no of cell sdying is greater than no. of cells dividing

TRUE OR FALSE: some microbes are better at rapidly dividing cells

substances containing nutrientss in which cells or microbes can be grown

characteristics of culture media

act of introducing microbes or suspension of microbes into a culture medium

microbial cells added to a medium in order to start a culture

nutrient material that contains a solidifying agent

allows for isolation and examination of colonies
difficult to transport and store
microbes are on the surface

inoculating needle is used to stab the solid medium
used for microbes that prefer reduced O2
cannot observed morphology in the culture media

tube of solid medium at an angle for higher surface area
for easy storage and transportation
microbes are on the surface

carbohydrates; unbranched polysaccharide obtained from the cell walls of some species of red algae

species of red algae that agar is obtained

melts at above 95 degrees celcius; once melted does not solidify until it reaches 40 degrees

nutrient material tha tlacks a solidifying agents

liquid medium in a tube, bottle, or flask
applicable if high concentration of bacteria is desired

nutrient material that contain less than or euqal to 1% solidifying agent

has multiple effect
types of culture media used for general purposes

non fastidious culture media

example of all purpose media

allows growth of desired microbes while suppressing the growth of unwanted microbes

culture media that has added antibiotic

example of selective media

media used in neiserria gonnorhea
used non sterile specimen

media used if certain that a sample contain only neisseria gonorrhea
uses sterile specimen (pure culture)

a chocolate agar plate with antibiotics

antbiotics that thayer martin agar contains

kills gram positive bacteria

kills gram negative bcteria except neisseria

kills fungi

grow gram negative bacteria and inhibits growth of gram positive bacteria

used for fungi growth so i tdiscourage dgrowth of bacteria
has a pH of 5.6

used for differnetiating between bacteri aby using an identification marker for specfic type of microbes

example of differential media

used for different s. aureus/ s. epidermidis species

color of s. aureus in mannitol sugar agar

color s. epidermidis in mannitol salt agar

othe rform if thayer-martin agar

inhibits growth of proteus species

contains thayer-martin agar and trimethroprim

gram negative lactose fermenting and non-lactose fermenting

has hemolytic properties for streptococcus

types of hemoltyic properties of microbes

green; a partial hemoylsis

clear; complete hemolysis

no visible reaction; no hemolysis

example of bacteria that has partial hemolysis

bacteria that has complete hemolysis

bacteria that ha sno hemolysis

favors growth of a particular microorganism over others b providing essential nutrients

example of enrichment media

contains hemolysed blood

bacterias grown in chocolate agar

contains horse serum, beef extract, dextrose, peptones

bacterias grown in loeffler's medium

bacterias grown in brain heart infusion agar

contains caseine peptone, potato infusion, glycerol

bacteria gron in bordet gengou agar

assess effect of concentration of substances

preprared from pure chemical substances of know (specific quantity) composition and concentration

example of chemically defined agar

exact components are difficult to eliminate because of complex ingedients

example of complex media

microorganism requiring special culture techniques

mycobacterium leprae

treponema palidum

obligate parasites (ricketssia/ chlamydia)

influenza virus

mycoplasma

a method of isolating a culture by spreading microbes over the surface

a method of inoculating a solid nutrient medium by mixing bacteria in the melted medium and pouring the medium into a petri dish to solidify

a plate count method in which inoculum is spread over the surface of a soli dculture medium

selectively grow campylobacter jejum

culture of mycobacterium tuberculosis