1a. Glucose fermented. 2a. Sulfur reduced. 3a. Lactose fermented…………………………………………Citrobacter freundii 3b. Lactose not fermented 4a. Sucrose fermented…………………………………….Proteus vulgaris 4b. Sucrose not fermented………………………………Proteus mirabilis 2b. Sulfur not reduced. 5a. Lactose fermented. 6a. Sucrose fermented. 7a. Ornithine decarboxylase present……Enterobacter aerogenes 7b. Ornithine decarboxylase not present…….Klebsiella pneumonia 6b. Sucrose not fermented……………………………….Escherichia coli 5b. Lactose not fermented…………………………………….Serratia marcescens
1b. Glucose not fermented 8a. Glucose oxidized…………………………….........…………Pseudomonas aeruginosa 8b. Glucose not oxidized…………………………………………......Alcaligenes faecalis
Test Question being asked Observations Interpretations
Gram Statin Is the unknown gram …show more content…
This test is designed to tell whether or not an organism can ferment glucose, reduce sulfur, and produce gas. The semi-solid, slant TSI test starts out as a burnt orange color and also contains phenol red, which is a pH indicator. When glucose is fermented, the solution becomes acidic, causing the TSI tube to turn orange. If the organism is unable to ferment glucose, the amino acids that are present in the TSI tube are fermented, causing the tube to turn pink. If sulfur can be reduced by the organism, the butt of the tube will have black precipitate in it. Sulfur is reduced when iron is oxidized in a TSI tube. If bubbles are present in the tube than the organism is a gas producer. The TSI test of my unknown resulted in a yellow slant and a yellow butt with black precipitate. Bubbles were not present in the tube. These results mean that my unknown can ferment glucose and possibly another sugar, as well as reduce sulfur. With these results, I concluded that my unknown was one of three organisms: Citrobacter freundii, Proteus vulgaris, or Proteus