12/08/2009
Microbiology 140
Matthew Tuthill
Unknown Lab Report
Introduction
There are many reasons for knowing the identity of microorganisms. The reasons range from knowing the causative agent of a disease in a patient, so as to know how it can be treated, to knowing the correct microorganism to be used for making certain foods or antibiotics. This study was done by applying all of the methods that I have been learned so far in the microbiology laboratory class for the identification of an unknown bacterium.
The purpose of this lab was to identify two unknown bacteria cultures using various differential tests. The identification of these unknown cultures was accomplished by separating and differentiating possible …show more content…
Production of this compound will cause a reaction to occur with ferrous sulfate and will result in the production of a black precipitate. Thus, the culture is positive for H2S production if a black precipitate is seen and negative if one is not observed. The yielding results after incubation was (A/A) for gram (-) bacteria and (K/K) for gram (+) bacteria, there were no black precipitate present in either tubes.
Flow chart
Unknown 126
Gram Stain (G+ Coccus)
Catalase (positive)
Positive Negative
Staph. aureus Strep. pyogenes
Staph. epidermidis Strep. aglactea
Staph. saprophyticus Enterococcus faecalis
Micrococcus roseus Strep. pneumonia
BAP
Gamma Other
Staph. Saprophyticus Staph. Aureus
Micrococcus roseus Staph. Epidermidis
TSI (k/k)
Negative Positive
Micrococcus roseus Staph. Saprphyticus
Urease (Negative) / Bacitracin (S)
Micrococcus roseus
Unknown 126- Micrococcus roseus
Conclusion:
With multiple differential and biochemical test runned on the unknown 126 I was able to single out the bacteria which lead to Micrococcus roseus. After running the test and observing the results I believe