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identifying unknown bacteria


            
            
             Identification of two unknown bacterial cultures through various laboratory techniques including selective and differential media, enriched media and other culture media to determine metabolic needs of the organisms. .
             .
             Materials:.
             Unknown Cultures (#127 & #128).
             BHIA Slants .
             MacConkey Agar Plates.
             Blood Agar Plates.
             TSI Slants.
             MR-VP Slants.
             Mannitol Salt Agar Plates.
             Urea Broth Tubes.
             Catalase Test (Hydrogen Peroxide).
             Methods:.
             Using aseptic transfer techniques inoculate the BHIA slants with the unknowns and then inoculate the MacConkey plates with the unknowns (one unknown for each slant and plate. After inoculating the agar plate streak each for isolation in case unknown culture is contaminated. Incubate all cultures for 48 hours. Observe cultures after incubation. Unknown #127 grew on the MacConkey but did not ferment lactose. The next step is to inoculate a TSI slant and inoculate a Urea Broth tube and let them incubate for 48 hours. Unknown #128 showed no growth on MacConkey so a catalase test needed to be performed which gave a negative result. The next step is to inoculate a blood agar plate and a Mannitol Salt Agar plate. Incubate the cultures for 48 hours and observe results.
             Results:.
             Data Table of Results .
             Media or Test Used Unknown # 127 Unknown # 128.
             .
             MacConkey Agar Growth with no fermentation No Growth.
             Catalase Test Not applicable Negative.
             Blood Agar Not applicable Beta Hemolysis.
             Mannitol Salt Not applicable No growth.
             TSI Slants Glucose-acid/gas, lactose (-), sucrose (+) and H2S (+) Not applicable.
             Urea Broth Positive Not applicable.
             Conclusion: .
             Unknown # 127 is the organism Proteus Vulgaris. This is concluded from the information gathered from the cultures and tests. There was growth on the MacConkey, which would indicate a gram-negative rod since MacConkey is a selective media that encourages gram-negative growth. MacConkey is also differential for lactose fermentation, but there was no fermentation reaction.


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