Quiz 3

fluid thioglycollate

determine oxygen requirements of bacteria

fluid thioglycollate reducing medium

any medium containing a reducing agent which removes oxygen from the media

reducing agent

removes oxygen from the media

fluid thioglycollate broth recipe

yeast extract, sodium thioglycollate, cysteine, resazurin, agar

general growth

what is yeast extract in fluid thioglycollate

reducing agents

what is sodium thioglycollate and cysteine in fluid thioglycollate

redox reactions

reactions of sodium thioglycollate and cysteine have in fluid thioglycollate

resazurin

indicate whether oxygen is present or not in fluid thioglycollate

pink

color resazurin turns when oxygen is present

colorless

color resazurin turns when oxygen is not present

agar in fluid thioglycollate

slows does the diffusion of oxygen

strict aerobe

requires oxygen

strict anaerobe

requires no oxygen

facultative anaerobe

utilizes oxygen but can also grow without oxygen

aerotolerant anaerobe

does not use oxygen but can grow in the presence of oxygen

microaerophile

requires small amounts of oxygen

SIM

sulfur reduction, indole, motility

SIM recipe

pancreatic digest of casein, ferrous ammonium sulfate, sodium thiosulfate, agar

cysteine and tryptophan

pancreatic digest of casein

protein

what is casein

amino acids

what are cysteine and tryptophan

H2S

ferrous ammonium sulfate detects

reducible sulfur

what is sodium thiosulfate

motility

what is agar used for in the SIM test

motility SIM

determine if bacteria are capable of motility, low % of agar promotes movement, movement can be visualized away from stab line

sulfur reduction SIM

determine if bacteria are capable of H2S production

hydrogen sulfide

what is H2S

cysteine desulfurase and thiosulfate reductase

sulfur reduction enzymes

cysteine

substrate in cysteine desulfurase

H2S, NH3, pyruvate

products of cysteine desulfurase

what is H2S

byproduct that allows us to determine if bacteria produces cysteine desulfurase and thiosulfate reductase; therefore, the bacteria is able to reduce sugar

pyruvate function

fermentation and cellular respiration

sodium thiosulfate

substrate in thiosulfate reductase

anaerobic respiration in electron transport chain

where does thiosulfate reductase take place

why does H2S get detected in the media

ferrous ammonium sulfate interacts with the H2S causing black precipitate

H2S

product of thiosulfate reductase

endoenzyme

what type of enzyme are cysteine desulfurase, thiosulfate reductase, and tryptophanase

indole

determine if bacteria can produce indole from tryptophan

tryptopahase

breaks down tryptophan into indole, NH3, and pyruvate

kovacs reagent

added to the SIM to detect indole and change the color of the media

tryptophan

substrate for indole

indole, NH3, pyruvate

products from tryptophanase

red/pink

color for positive result for indole

triple sugar iron

to aide in the identification of gram-negative rods

slant TSI

aerobic

butt TSI

anaerobic

TSI agar recipe

beef extract, yeast extract, peptones, lactose, sucrose, glucose, ferrous ammonium sulfate, sodium thiosulfate, phenol red

general growth factors TSI

beef extract, yeast extract, peptones

peptones TSI

amino acids

cysteine from peptones TSI

reduce sulfur

color of general growth factors TSI

red/pink; alkaline

color of sugars TSI

yellow; acidic

what do the sugars do TSI

test if the bacteria use glucose

glucose

sugar bacteria will use first TSI

when can the bacteria use lactose and sucrose TSI

can only use if the bacteria carries enzymes that will break down those sugars

ferrous ammonium sulfate

H2S indicator

black precipitate

what does ferrous ammonium sulfate and sugar make TSI

sodium thiosulfate

source of reducible sulfur

phenol red

pH indicator

yellow

phenol red acidic (A) color

red/pink

phenol red alkaline (K) color

A/A TSI result and interpretation

bacteria ferments glucose and lactose and/or sucrose

A/A, H2S TSI result and interpretation

bacteria ferments glucose and lactose and/or sucrose, makes thiosulfate reductase, butt more acidic due to fermentation (no oxygen)

K/A TSI results and interpretation

bacteria ferments glucose and performs peptone catabolism; if it used all sugars then it would all be yellow

K/A, H2S TSI result and interpretation

bacteria ferments glucose, peptone catabolism, and produces hydrogen sulfide

K/K TSI result and interpretation

bacteria goes through peptone catabolism

capsule stain

to differentiate capsule producing organisms

capsule

sticky, gel-like layer surrounding the cell

polysaccharides and/or polypeptides

what is the capsule composed of

no

do all bacteria have a capsule

neutral

what charge does the capsule have

capsule advantages

avoid phagocytosis and attach to surfaces or other cells

virulence factor

molecules that can help the organism thrive and cause disease

yes

is the capsule considered a virulence factor

negative stain

what stain is the capsule stain similar to

acidic stain

what stain is used for the capsule stain

negative

acidic stain charge

why does the capsule not stain

it has a neutral charge

basic stain

what stain stains the cell but not the capusle

positive

basic stain charge

why do we not heat-fix during a capsule stain

the capsule is sensitive to heat

endospore stain

differentiate bacteria that form endospores from non spore formers

Clostridium and Bacillus

organisms that form endospores

endospore function

survival of adverse conditions

adverse conditions

lack of nutrients, lack of water, temperature, pH

sporulation

formation of an endospore

germination

formation of a vegetative cell from an endospore

vegetative cell

metabolically cell that can go through cell division

mother cell

endospore completely in the cell, is stained two different colors

free endospore

will have different coats protecting the DNA inside

keratin

helps endospore be resistant to chemicals

central endospore

endospore located in the middle of the cell

terminal endospore

endospore located at the end of the cell

subterminal endospore

endospore is located between the end and middle of the cell

malachite green

endospore primary stain

what is malachite green

water soluble, basic stain, positive charge

what does malachite green do in an endospore stain

stain vegetative cells, mother cell, and endospore

water

endospore decolorizer

what does water do in an endospore stain

decolorizes vegetative cell along with the vegetative part of the mother cell

safranin

endospore counterstain