Introduction
Escherichia coli or more commonly known as E. Coli is a gram negative, facultative anaerobic bacterium that is commonly found in the lower intestine. There are many different strains of E. Coli, with strains that are created in a laboratory setting that are used as a standard for testing other strains of e.coli.1 These special strains possess an inherent tetracycline resistance from the insertion of a “marker” 2’ upstream or downstream from a targeted gene. These tetracycline marked strains possess the same genome as wild type strains, and thus through conjugation can transfer a tetracycline resistance. The particular strain used in this experiment was the wild-type CV1437 non-pathogenic E.Coli that has an innate resistance to …show more content…
E.Coli has a circular DNA, with genes in the DNA encoding specific proteins that contribute to the form and function of the cell. These proteins are planned by using the base-pair blueprint from the DNA, where it is then transferred from the nucleus to the ribosomes to be translated and chained together with amino acid sequences.4 E. Coli is the most widely studied prokaryotic organism in part due to the rate at which E.Coli. can grow, and also due to the fact that it has the ability to transfer DNA through bacterial conjugation and transduction which is used in these experiments.5 Conjugation is the transferring of DNA from cell to cell with direct contact. During conjugation, the DNA in a circular form from one bacterial cell is replicated and transferred to the bacterial cell that has made direct contact with the original cell. One strand of the DNA is transferred to the recipient cell and the other strand stays with the donor cell. Transduction, unlike conjugation, does not require direct contact between cells. Transduction occurs through the lytic cycle which is induced by UV light and produces phage particles that are released to the recipient cell or through the lysogenic cycle.2 Another important aspect of E.Coli is that the organism possesses flagella, appendages that extend from the cell wall allowing the cell to move through …show more content…
Kanamycin acts by binding to the active site of the small s-ribosomal subunit, an important functioning part of the organelle. Kanamycin inhibits the synthesis of the protein by causing an increased amount of mistranslation. The other antibiotics used in the experiment are Tetracycle and Streptomycin, both which act in different methods than Kanamycin. An important factor in the experiment, and the genesis of our discovery, was the UV mutations in the bacterial genome. UV light is an extremely high-energy particle, and extended exposure to concentrated amounts of this light can cause an error in base pair reading by RNA polymerase due to thymine dimers. These thymine dimers cause the normally linear reading polymerase to perceive the DNA as a bubble; either passing it entirely, or just coding the complementary strand incorrectly. The longer the exposure to UV light, the more inconsistencies in the genome.3 The basis for this experiment is to use UV mutation long enough to cause a Kanamycin resistance, by causing changes in several genes of interest, and producing a non-motile strain by mutations in several flagellar gene clusters. By using intervals of UV light, you can generate a UV killing curve, a model that allows you to select the amount of bacterial
Escherichia coli or more commonly known as E. Coli is a gram negative, facultative anaerobic bacterium that is commonly found in the lower intestine. There are many different strains of E. Coli, with strains that are created in a laboratory setting that are used as a standard for testing other strains of e.coli.1 These special strains possess an inherent tetracycline resistance from the insertion of a “marker” 2’ upstream or downstream from a targeted gene. These tetracycline marked strains possess the same genome as wild type strains, and thus through conjugation can transfer a tetracycline resistance. The particular strain used in this experiment was the wild-type CV1437 non-pathogenic E.Coli that has an innate resistance to …show more content…
E.Coli has a circular DNA, with genes in the DNA encoding specific proteins that contribute to the form and function of the cell. These proteins are planned by using the base-pair blueprint from the DNA, where it is then transferred from the nucleus to the ribosomes to be translated and chained together with amino acid sequences.4 E. Coli is the most widely studied prokaryotic organism in part due to the rate at which E.Coli. can grow, and also due to the fact that it has the ability to transfer DNA through bacterial conjugation and transduction which is used in these experiments.5 Conjugation is the transferring of DNA from cell to cell with direct contact. During conjugation, the DNA in a circular form from one bacterial cell is replicated and transferred to the bacterial cell that has made direct contact with the original cell. One strand of the DNA is transferred to the recipient cell and the other strand stays with the donor cell. Transduction, unlike conjugation, does not require direct contact between cells. Transduction occurs through the lytic cycle which is induced by UV light and produces phage particles that are released to the recipient cell or through the lysogenic cycle.2 Another important aspect of E.Coli is that the organism possesses flagella, appendages that extend from the cell wall allowing the cell to move through …show more content…
Kanamycin acts by binding to the active site of the small s-ribosomal subunit, an important functioning part of the organelle. Kanamycin inhibits the synthesis of the protein by causing an increased amount of mistranslation. The other antibiotics used in the experiment are Tetracycle and Streptomycin, both which act in different methods than Kanamycin. An important factor in the experiment, and the genesis of our discovery, was the UV mutations in the bacterial genome. UV light is an extremely high-energy particle, and extended exposure to concentrated amounts of this light can cause an error in base pair reading by RNA polymerase due to thymine dimers. These thymine dimers cause the normally linear reading polymerase to perceive the DNA as a bubble; either passing it entirely, or just coding the complementary strand incorrectly. The longer the exposure to UV light, the more inconsistencies in the genome.3 The basis for this experiment is to use UV mutation long enough to cause a Kanamycin resistance, by causing changes in several genes of interest, and producing a non-motile strain by mutations in several flagellar gene clusters. By using intervals of UV light, you can generate a UV killing curve, a model that allows you to select the amount of bacterial