oxygen requirements Flashcards
what is the thioglycollate broth composed of ?
small amounts of agar, redox indicator, and sodium thioglycollate.
why is there only small amounts of agar in the thioglycollate broth?
to limit diffusion
what does a redox indicator do?
reveals oxygen rich areas, shows as pink
what does the sodium thioglycollate do in thioglycollate broths?
reduces O2 to H2O
what are the two types of thioglycollate broths we will see in lab?
facultative anaerobes and areobes
facultative anaerobes
prefer to live in O2 enviorments but can live without it.
(moslty growth on top but a few throughout)
obligate/ strict anaerobes
Dont use O2 and CANNOT live in it
(all growth towards the bottom)
aerobes
require oxygen for metabolism
(growth all on top)
aerotolerant
Dont use O2 in metabolism and CAN be in its presence
(growth is evenly distributed)
microaerophiles
2-10% O2
what are the examples of monosaccharides?
glucose, galactose, mannose
what are the examples of Disaccharides?
sucrose, lactose, maltose
what is the polysaccharide?
starch
what does phenol red broth tubes use as an indicator?
red pH indicator
when using the phenol red broth tubes, what is the test looking for? what color does the broth turn?
acid production, yellow coloration
what tube is used to test the carbohydrates? what does it do?
durham tube, detects CO2 production
in the TSI agar slants, what percent of acid production in glucose, lacotse and sucrose is there?
glucose: 0.1%
lactose and sucrose: 1%
what is another name for the triple sugar iron slants?
kligler slants
if glucose is used only the _____ of the tube will turn _______?
butt, yellow
T/F in TSI slants, If lactose and/or sucrose is used then both the butt and the slants will turn yellow?
T
how do you know if there is CO2 production in the triple sugar iron slants?
if there are cracks or lifting of the agar
what does the iron do in the TSI slants?
gives the organism the ability to express thiosulfate reductase
what is thiosulfate reductase used in?
used in sulfer reduction
in the TSI, what is produced from thiosulfate?
H2S
In TSI, whats helps produce the black precipitate?
ferrous ammonium sulfate
when using a starch there are many glucose units that are too large to get through the membrane, what enzyme is used to break it down? where is it secreted?
amylase, secreted outside (exoenzyme)
when using the starch plates, after you pour the iodine how long do you incubate for?
1 minute
When using starch plates, after the iodine is poured off, what does it mean when the plate is brown all over? what does it mean when there is a zone of clearing around the bacteria?
brown all over = has starch
zone of clearing= no starch
What is motility, and what percent agar is used?
the use of semisold agar, (0.8% agar)
When testing motility how does the 2,3,5 triphenyltetrazolium (TTC) work?
its colorless, but as the organism grows the dye will be incorperated in the bacteria and reduced to a red insoluable pigment.
What is the process of 2,3,5 triphenyltetrazolium (TTC) working in the motility test called?
formazan
when testing motility, what is added to see the results?
2,3,5 triphenyltetrazolium (TTC)
what are examples of facultative anaerobes
fermentation and anaerobic respiration
if you inoculated a semi solid agar that contained triphenyltetrazolium chloride, how would the tube look after incubation with a nonmotile bacterium?
the tube would have a small amount of growth around the inoculated needle insertion with a red insoluble pigment.
