Unknown Lab Report

1996 Words8 Pages
Unknown Lab Report: Enterobacter cloacae Jessica Sainvil Professor Cupido Bio 253L1 Thu 9:30-12:30 Due Date: 12/6/12 Unknown#103 Introduction The bacterium Enterobacter cloacae isolated from the given #103 was a Gram-negative Rod. The purpose of this lab was to isolate and identify the genus and species of an unknown bacterium. It is important to identify an unknown microorganism because knowing how the bacteria work and how it is structured means knowing how it can affect humans. Unknown bacteria may also be used clinically many pharmaceutical drugs are based on products made by organisms (Katzung, B.G.2004). In order to identify the unknown organism a series of tests were performed. The tests used were glucose, sucrose, lactose fermentation; Urease, motility, MR-VP, citrate, oxidase, and indole these tests were used to identify the genus of the unknown and a McConkey agar plate was used to differentiate and confirm the species of the unknown. This report will explain and give more in depth reasons why certain tests were done and the results yielded from them. Materials & Methods On the first day after receiving the unknown microorganism a streak plate was aseptically done as shown in exercise 2 of the lad manual (Kleyn 9). The streak plate technique is done to isolate a colony formed by a single cell from a mixture containing millions of cells. The streak plate technique was also used to obtain pure cultures of the bacteria using a trypticase soy agar (TSA) plate and was incubated at 37 ̊ for 48 hours. Secondly a Gram stain was performed as directed from exercise 6in the lab manual (Kleyn 37) and was found to be Gram negative Rods. The Gram stain is important to do because it reveals the morphology of the organism and the arrangement of the cells; if an organism appears purple under a microscope then it is said to be Gram positive, and if it

More about Unknown Lab Report

Open Document