Advertisement Upgrade to remove ads

What does the TSI test stand for?

Triple Sugar Iron

What is TSI composed of?

0.1% Glucose + 1.0% Lactose + 1.0% Sucrose + Phenol Red + Sodium Thiosulfate + Ferrous Ammonium Sulfate

What kinds of tests is the TSI test a mixture of?

Carbohydrate fermentation tests (involving sugars and phenol red) and the S in SIM test (testing for liberation of thiosulfate)

Liberation of Thiosulfate in the area of the TSI (as seen in the SIM test) produces what?

H2S

When doing the carbohydrate fermentation of the slant, what possible results would you have if you have both a yellow slant and a yellow butt. What does this mean was NOT produced?

either 1) lactose was fermented, 2) sucrose was fermented, 3) lactose & sucrose were fermented, or 4) lactose & sucrose & glucose were fermented; indicates that the fermentation of ONLY glucose was not present.

During the carbohydrate fermentation, what color(s) indicate that only glucose was fermented? What is this due to?

yellow butt and red slant; because by fermenting only 1/10th of a percent of glucose (all that was in there), enough acid isn't produced to turn all of phenol from red to yellow

What is another reason that the butt of the slant is being stabbed? What will you expect to see and why?

to test for gas production; because there is no durham tube to catch the gas, if CO2 is released, you will have "Agar Disruption"

How do we determine if hydrogen sulfide (H2S) gas reacted with Ferrous Ammonium Sulfate?

produce ferrous sulfide is produced which is a black ppt

yellow slant + black butt =

more than just glucose fermented and ferrous sulfide was produced

red slant + yellow butt =

H2S production and no gas production

yellow slant/butt + agar disruption =

no H2S formation, gas production with more than just glucose fermented

yellow slant + yellow butt =

gas production, no H2S, both slant and butt are acid but more than just glucose fermented.

Which types of bacteria will we be inoculating with during the TSI experiment?

1 slant with E. coli and 1 slant with Proteus

What is it that gives milk its white color?

Casein protein

When doing the casein test, with what and how will the streak plate be inoculated?

line drawn down middle of back; one side labeled bacillus and one side labeled E. coli; streak once with each on their respective sides

During tho experiment, release of CO2 gas proves what?

fermentation of sugars

Some bacteria can breakdown casein protein by use of what enzyme?

proteases

The breakdown of casein is also known as what?

proteolysis

What will a positive Casein Hydrolysis test look like?

zone of proteolysis around the streak that is clear-ish

How was the agar plate made? What is specifically important and why?

Used plate count agar, mixed up, then add 10% of skim milk; % of skim milk is important: enough to be milky cloudy, but can't have so much that it dilutes agar and keeps it from setting up (Balances amount is about 10%)

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set