Analysis Of The Carbohydrate Fermentation Test

The Carbohydrate Fermentation Test measured the ability of the bacteria to ferment glucose and mannitol carbohydrate and produce gas. Majority of microorganisms obtain energy from either aerobic or anaerobic respiration, or through fermentation. The different types of fermentation pathways used by bacteria can aid in differentiating them among groups or species of bacteria because each pathway depends on the complement of enzymes available for the cell (Department of Biological Sciences, 2015). The identification of the bacteria can be determined through the characteristic end products of each fermentation pathway. The Carbohydrate Fermentation Test was conducted in a two phenol red broth tubes that contained a fermentation broth that provided all the necessary nutrients for most microorganisms to grow, a phenol red pH indicator that changed colors at an acidic pH, and a specific …show more content…
The Bile Esculin test was performed on a Bile Esculin Agar slant by inoculating the slant in a zig-zag pattern and was stabbed using an inoculating needle. The slant was then incubated at 37°C for 48 hours. After incubation, the slant was taken out and observed for any change. The Bile Esculin Agar used in the test was used as a selective and differential medium. The bile that was in the medium was selective for streptococci and enterococci and inhibited the growth of Gram-positive staphylococci (Atlas & Snyder, 2015). The test differentiated between Streptococcus bovis group and Enterococcus from other streptococci based on the bacteria’s ability to hydrolyze esculin in the presence of bile. When esculin is hydrolyzed the byproduct reacts with ferric citrate and forms a dark precipitate on the medium (Atlas & Snyder, 2015). A Bile Esculin-positive result is if the media darkens around the bacteria and a negative result is if there is no darkening of the