Bacteria can be classified as gram positive or negative (difference in call wall). Gram positive bacteria have a thick cell wall of peptidoglycan (“polymer of disaccharides cross-linked by shorts chains of amino acids”), and stains purple after the staining procedure under a microscope (Todar, Kenneth,
Amir Ahemedin Ms.Buckley Genetics 11/06/15 Transformation of E.coli Lab Purpose The purpose of this lab is to genetically engineer the E.coli strain by introducing two genes, the green fluorescent protein gene (GFP) and the ampicillin resistant gene (AMP). Then observe whether or not the E.Coli strain would take up these genes and become fluorescent. Background Information In this lab, bacterial transformation was one of the three processes that occurred when genetic material is introduced to a bacterial cell. Bacterial transformation is important because it allows for the cloning and movement of DNA between strains. This transformation usually occurs within plasmids, which are closed circular molecules made up of double stranded DNA.
After a gram stain was done unknown #257 was identified as a gram positive organism because when observed under the microscope the organism appeared purple with cocci in clusters. The organism was also catalase positive which means that it produced enzyme catalase and bubbled when hydrogen peroxide was added to it. Three test were conducted based on the result of the gram staining procedure. Blood agar with a Novobiocin disk was chosen as well as DNase (DNA) and Mannitol Salts (MSA) agar. The Blood agar is a bright red, opaque plate and the streaking or the inoculation technique was a modified streaking for isolation with a heavy quadrant one.
The six bacteria used in this lab were, Citrobacter freundii, Bacillus subtillis, Enterobacter aerogenes, Staphylococcus epidermis, Enterococcus durans, and Escherichia coli. Citrobacter freundii is a Gram-negative rod shape bacteria. The MSA plate will grow Citrobacter freundii, Bacillus subtillis, Enterobacter aerogenes and will have a yellow color change while Staphylococcus epidermis will not grow nor have a color change to yellow. The MacConkey agar will have growth with Escherichia coli, Enterococcus durans, but not Staphylococcus epidermis and Bacillus subtilis since it is a Gram-positive. Only Escherichia coli and Enterococcus durans will be the species fermenting.
Bacteria taking up foreign DNA is known as transformation. Transformation implies uptake in bacterial, yeast or plant cell DNA while transfection is the term used in reference of mammalian uptake. Chemical transformation, electroporation or particle bombardment is the typical method of construct into a host cell. Conjugation: The easiest illustration is to consider this as a version of bacterial sex. In conjugation the two bacterial cells connect, and the male donates a piece of DNA to the female.
A plaque assay is a modification of a bacteriophage assay and is used to estimate the titer (concentration of a solution) of a phage stock. A plaque assay contains a virus combined with bacterial cells on the surface of an agar plate. The agar plate inhibits the spread of viral progeny to neighboring bacterial cells which results in plaque formation (lysis of bacterial cell). The purpose of this lab was to perform a bacteriophage assay and to calculate the original stock titer of the phage stock using the known set of dilutions and direct plaque count. The hypothesis for this experiment was that plaques will form on all the agar plates within a range count of 30 to 300.
Lastly is the evolution of MRSA (Methicillin-resistant Staphylococcus aureus). MRSA is a bacterium that is responsible for various infections in humans that are difficult to treat due to its development of a resistance to common antibiotics. MRSA is very common in hospitals, prisons, and nursing homes. Biological Diversity
Gram Stain Test The Gram Stain test was first performed to differentiate the bacteria based on the thickness of the peptidoglycan layer in its cell wall. The unknown bacteria appeared purple and round, therefore indicating a gram-positive cocci bacterium. The purple color was observed because S. agalactiae had a thicker layer of peptidoglycan in its cell wall, therefore it allowed for the cell wall to not be stripped away after the addition of ethyl alcohol, but rather enabled for the peptidoglycan to form pores (Madani, 2003). The pores then trapped the crystal violet-iodine complex, which produced the purple color of the bacteria cells that were observed under the light microscope. Catalase Test To further identify the gram positive unknown bacteria, the Catalase test was conducted in order to differentiate the gram-positive species into the Staphylococcus species (catalase-producers) or the Streptococcus species (catalase
ESI–MS m/z 297 [M+Na]+ in positive ion mode and 273 [M-H] in negative ion mode for molecular formula C15H14O5; 274. Compound 2 Commonly known as phlorizin. IUPAC name is 1-[2,4-dihydroxy-6-[(2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydropyran-2-yl]oxy-phenyl]-3-(4-hydroxyphenyl)propan-1-one was obtained as white to offwhite needle shaped crystals mp 1670C. The UV/Visible spectrum of the compound showed λmax at 226
Synthesis, molecular modeling and bio-evaluation of cycloalkyl fused 2-aminopyrimidines as antitubercular & antidiabetic agents 1. Introduction: o The target name and type: The target in this paper is the mycobacterial di-hydro folate reductase, alpha-glocosidase and glycogen phosphorylase The type of the targets is enzymes. o Diseases that associated with the target: The diseases that associated with the target are diabetes and tuberculosis. o Biological activity of the compounds: Minimum inhibitory concentration (MIC): Susceptibility of the organisms which is isolated from the clinical specimens is determined with diffusion tests, and this test has some limitations. At the time of prolonged infection such as bacterial endocarditis or when