Lab 28: Production of Hydrogen Sulfide

Question 1

this test determines

Answer 1

the ability of microorganisms to ferment cysteine to the end product hydrogen sulfide

Question 2

what is TSI

Answer 2

triple sugar iron agar which contains cysteine and an iron salt that reacts with H2S to form a black precipitate. also contains glucose, sucrose, lactose and phenol red. contains beef and yeasts extracts

Question 3

if one of more carbohydrates is fermented then

Answer 3

phenol red changes the media from red to yellow

Question 4

production of H2S is useful for differentiating

Answer 4

Enterobacteriaceae

Question 5

results:
red slant=
yellow slant=
bubbles or tears=
butt of tube black=

Answer 5

red slant=neg
yellow slant= pos
bubbles or tears=CO2
butt of tube black=H2S