Do you really want your change back?

Essay by rcdav5College, UndergraduateB+, April 2014

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Davey 1

Sarah Davey

Catherine Ennis


Intro to Microbiology

Are you sure you really want your change back?

Abstract: The purpose of this experiment was to swab for an unknown bacteria. Then to use knowledge about different techniques and Medias learned about in Microbiology lab and lecture to determine the identity of the unknown bacteria. This was done by swabbing and then growing the culture on a nutrient agar plate, isolating for one bacteria, Gram staining to find morphology and gram status, taking a biochemical catalase test, Eosin Methylene Blue, Simmons Citrate, and Triple Sugar Iron Test all to select and differentiate the type of bacteria that had been isolated. Through the results of the tests applied the bacteria was determined to be Micrococcus luteus.

Introduction: Aseptic technique was used to obtain the unknown bacteria, a sterile swab and gloves were used. Aseptic technique was used to avoid unwanted contaminants (Nicholson) The lab professor instructed the class to search the campus for a public used fomite.

The sterile swab was saturated with distilled water then used to take a sample of bacteria from the return change drawer of a soda machine. The swab was immediately used to inoculate a Nutrient Agar plate; a general-purpose nutrient medium used for the cultivation of microbes and put in an incubator for 24 hours at 37 degrees Celsius. (Ennis, C 2013). Nutrient Agar is frequently used for isolation and purification of cultures (Nutrient Agar Plate). It consists of heat-stable digestive products of proteins (called peptones) and beef extract. (Nutrient Agar Plate) Both of these provide amino acids, minerals, and other nutrients are used by a wide variety of bacteria for optimal growth (Nutrient Agar Plate) After the bacteria was grown, an isolation streak was performed on another nutrient agar plate the following...