Unknown Lab Report
April 9, 2012
Identifying an Unknown Bacteria
Knowing the identity of a microorganism is extremely beneficial. Knowing what you are dealing with can allow one to knowing the causative agent of a disease and how it can be treated. The purpose of this lab was to identify an unknown microorganism by using various differential tests. These experiments separated and differentiated bacteria based upon specific characteristics. The experiments included identifying shape and motility, gram staining, endospores, oxygen, glucose, lactose, mannitol, VP, MR, citrate, nitrate, catalase, and oxidase. If I perform theses experiments correctly and accurately then I will be able to identify my unknown bacteria. Materials/Methods
The different tests performed on the bacteria were all done in order to determine the identity if an unknown bacteria. Identifying the shape of a bacteria allows one to not only determine how a bacteria looks physically, but can also be applicable in naming a bacteria. Motility is if a bacteria is mobile or immobile. Motility is determined to find if one’s bacteria is alive or not; if bacteria is moving then that means it is alive and if the bacteria is not moving that indicates the bacteria is dead. Gram staining indicates if there is peptidoglycan in the cell walls of the bacteria or not. In gram staining the reagents use where crystal violet for the primary stain, Gram’s iodine for the mordant, 95% ethyl alcohol for the decolorizing agent, and safranin for the counter stain. If a bacteria contains peptidoglycan in their cell walls then that bacteria is considered to be gram positive and will turn purple. If the cell does not contain peptidoglycan in their cell walls then the bacteria is gram negative and will turn purple. “Endospores are formed by a few genera of gram positive bacteria. Endospores are specialized for survival in unfavorable...
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