Biology 258-05
November 26, 2012
Unknown #19
Enterbacteriaceae Enterobacter aerogenes
ABSTRACT
The objective of this report was to identify an unknown microorganism through several differential media tests. Over the course of a couple weeks, ten tests were performed. First, a gram stain was performed, indicating the bacterium was gram negative. An aerotolerance test determined that the bacterium was a facultative anaerobe. Next, a negative result in the methyl red test indicated that no mixed acid fermentation occurred. The DNase test was performed and yielded a positive result. The SIM test provided two outcomes, that the bacterium did not reduce sulfur nor produce indole from tryptophan. Afterwards, the bacterium was determined to be positive for lysine decarboxylation and citrate. The purple broth and triple sugar iron tests both indicated gas production. The purple broth test was positive for fermentation, and the triple sugar iron test indicated that the bacterium fermented glucose and sucrose. Finally, the bacterium was urease negative.
Based on the results of the tests performed, the microorganism was identified as Enterbacteriaceae Enterobacter aerogenes.
INTRODUCTION Microbiology is a specialized area of biology that places an emphasis on microorganisms. Several microorganisms are included in this subject, such as bacteria, fungi, algae and protozoa. The most important fact that should come out of microbiology is the “profound influence” that microorganisms have on the aspects of earth (Cowan, 2012).
The objective of this project was to identify an unknown bacterium through several differential tests. Identifying an organism can be very beneficial in the field of medicine. Knowing what an organism is can indicate its pathology and treatment. These tests are designed to find out about an organism’s metabolism and other various characteristics. For this project, ten
References: Cowan, Marjorie Kelly. Microbiology: A Systems Approach. 3rd ed. Miami: McGraw Hill, 2012. 2-24. Print. "Enterobacter aerogenes." Antimicrobial Copper. Internation Copper Association, n.d. Web. 21 Nov 2012. Michaels, Joel. "Enterobacter aerogenes Characteristics." eHow Health. Demand Media, Inc.. Web. 22 Nov 2012.