Danielle NaserProfessor Jennifer GrahamNovember 5,2014Lab 5Phenol-Red Carbohydrate Fermentation BrothsIntroduction-The main purpose for this lab experiment was to distinguish the ability of microorganisms to degrade and ferment carbohydrates with the production of acid and gas. This experiment also helped to understand the differences between cellular respiration and fermentation. Fermentation is a metabolic process performed by almost all types of bacteria. This will result in the production of ATP, the ultimate energy source of the organism. This will happen either in the presence of absence of atmospheric oxygen. The carbohydrate test is used for the fermentation of lactose, sucrose, and ...view middle of the document...
4 Phenol-Red Mannitol
4 Phenol-Red Sucrose
4 Phenol-Red Dextrose
Procedure-(The material and methods used for this lab can be found in Cappuccino, J.G., N. Sherman.2014. Microbiology: a laboratory manual. 10th Ed. Pearson Education, inc.) The organisms used in this lab were Escherichia Coli, Micrococcus Luteus, Salmonella thyphimurium and lastly Staphylococcus Aureus.Results-Acid production: Changes the medium into yellow color-organism ferments the given carbohydrate and produce organic acids there by reducing the ph of the medium into acidic.Acid and Gas production: Changes the medium into yellow color-organism ferments the given Carbohydrate and produce organic acids and gas. Gas production can be detected by the presence of small bubbles in the inverted Durham tubes.Absence of fermentation: The broth retains the red color. The organism cannot utilize the carbohydrate but the organism continues to grow in the medium using other energy sources in the medium.
E-coli- Yellow change color (+) with gas
E.coli- Yellow change color with gas (+)
E.coli- Yellow color change
S. Aureus-Yellow change color (+)
S.Aureus- yellow color change
S.aureus- Yellow color change
M.Luteus- Yellow change color (+) with gas
M.Luteus-Yellow change color (+) and gas
M.Luteus- No Change (-)