E. Coli : The Bacteria Of Interest Is Essential For Survival Of The Bacterium

2621 Words Apr 16th, 2015 11 Pages
Plasmids are extra chromosomal DNA within some bacteria that exist as circular structures. Although they are not essential for survival of the bacterium, they often do confer many environment advantages such as antibiotic resistance. One bacteria of interest is E. coli, a gram-negative organism that is part of normal human gut flora. Some strains of E. coli are pathologic to humans, however some strains are beneficial. For example, one strain produces vitamin K, an essential nutrient. In this experiment, E. coli was introduced to two plasmids: pUC18 and lux. Plasmid pUC18 contains a gene that codes for the enzyme beta-lactamase which renders ampicillin and some other antibiotics inactive. Plasmid lux found in V. fischeri contains an operon that codes for luciferase, an enzyme that is involved in a light creating reaction. Within this experiment CaCl2 was used to increase E. coli’s ability to take up plasmids. Once E. coli was able to take up pUC18 and become resistant to ampicillin lux was used to identify E. coli through its light-emitting reaction. The results of this experiment failed to show that E. coli with the ampicillin resistant plasmid could grow in the presence of ampicillin. However, this was most likely due to several sources of error such as inaccuracy, contamination, and possible killed bacteria. Numerous experiments as well as the literature have proven substantially that transformation does exist and specifically that E.coli can develop resistance to…

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