Lecture 17: Enzyme-Mediated Biochemical Activities of Bacteria: Physiological Testing III

I. Lab 16 results

A. Staphylococcus and Streptococcus spp.

1. Coagulase- enzyme the effectively ________________________ ___________________.

-Staphylococcus aureus - ________________________
-Staphylococcus epidermidis - ________________________

2. Taxos P- is a disk that contains _______________________

-Streptococcus pneumoniae - ______________________
-Streptococcus mitis - ______________________

3. Taxos A- a disk that contains ________________________

-Streptococcus pyogenes - _______________________
-Staphylococcus aureus and other, less pathogenic Streptococcus spp.(e.g. Streptococcus agalactiae) - _________________________

B .Gram-negative bacilli
Kligler’s Iron Agar (KIA)

1. differentiates bacteria based on their ability to ferment ______________ ______________________.

-The KIA test is often used to identify ______________________ _______________________(e.g. Shigella), which are often more ___________________________________ in the GIT.

2. Gas produced as a product of fermentation will form ____________

_________________ or completely _________________________ ______________________________________ of the tube.

- ____________________________ and ____________________ _____________ produce gas.

3. The production of H₂S results in a _________________________.

*If the black precipitate obscures the medium color, it is _______________ __________________________________________________.

2. The Nitrate Test: determines an organism’s ability to reduce _______ ________________________________________ using the enzyme nitratase. 

Procedure:

*Note-there are ___________________________ for an organism to be positive for nitrate reduction and only _____________________________ to be negative.

Expected Results:

II. Unknowns

A. Take one unknown Gram-negative and one Gram-positive. Both the Gram-negative and the Gram-positive should have the _______________________ ______________________.
B. Be certain to _________________________________ all tubes/plates/slides so as not to confuse the Gram-negative and Gram-positive.
C. Perform a ________________________________ of both unknowns and streak for isolation. It is very important to get an isolated colony!
D. Be certain that you also receive a clue for both the Gram-negative and Gram-positive. These clues will assist you in writing your hypotheses which are __________________ (along with your references) ______________ _______________________________________. Please see the description of this assignment in the lab notebook.

Rachel Watson, M.S.
AG 5010
766-3524
Cell: 307-314-9636
rwatson@uwyo.edu