Bacterial Conjugation Lab Report

What was expected that the strains of E. coli that did not have a resistance to ampicillin would not grow. The transformed strain also changed to a blue color when the X-gal was present in plate. The transformed cells also grew because they were free of the ampicillin because they possessed the amp gene that they used as an shield against the ampicillin antibiotic. The transformed cell who turned blue did so because the gene converted the sugar to a blue color but also contained the amp gene to ensure that they grew even when the ampicillin was present. The growth of the colonies on the plates

(Biology Dept.). 0.1 ml of E.coli K or 0.1ml of E.coli B was added to the 10 fold dilution. Using soft agar technique, the growth media mixture with E.coli was plated and incubated.

Citrobacter Freundii is a species of bacteria that can be potentially harmful to humans. It is known to cause meningitis by protruding into the brain and replicating itself (1). The Citrobacter species has also been found as a cause of some urinary tract infections, diarrhea, and even gastrointestinal diseases and symptoms (3). C. Freundii can be located in a wide variety of soils and water (3). Lastly, it is also the cause of many nosocomial infections due to its presence in water (1).

70µL of competent E.coli are added to both test tubes; pUC18 and Lux (Alberte et al., 2012). Both test tubes are then tapped and placed back into the ice bath for 15 minutes. While waiting, another test tube is obtained, filled with 35µL of competent cells and labeled NP for no plasmid. A water bath is preheated to 37 degrees Celsius and all three labeled test tubes are inserted into the bath for five minutes (Alberte et al., 2012). Using a sterile pipet 300µL of nutrient broth are inserted into both the control and Lux test tubes and 150µL are inserted to the no plasmid test tube to increase bacterial growth. All three test tubes are then incubated at 37 degrees for 45 minutes. Six agar plates are obtained and labeled to correspond each test tube, three of the plates contain ampicillin. A pipet is used to remove 130µl from each test tube containing a plasmid and insert it into the corresponding agar plate. For this, a cell spreader is first

The purpose of the bacterial unknown independent study experiment completed throughout the course of this lab was to determine the identity of an unknown bacterial species. The unknown bacteria sample was chosen from numerous samples provided by the instructor. The starting unknown sample, unknown #15 was a mixed bacterial culture and a broad approach taken to identify the sample. Various biochemical tests were completed to identify the bacterial species along with the use of databases such as Gideon and Bergey’s to compare the test results of known bacteria to the results of the unknown sample. Information was gathered from the other sources and databases and phenotypic testing completed and the results compared to the database results. Aseptic

E. coli is a bacterium capable of being transmitted from one person to another. To ensure that the bacteria used in this experiment were not transmitted to other places, items, or organisms, several safety protocols were followed.

Escherichia coli, or E. coli, is a common bacterium that can be found in diverse environments all over the planet, including the gastrointestinal tracts of animals and humans. Many of these strains of E. Coli are essential mechanisms in the digestive tract, while others are pathogens that can cause complications in urinary and intestinal tracts. (Payne & Sparks) In research, E. Coli is commonly used as a model organism, meaning they are widely studied by scientists for a variety of purposes due to their experimental advantages. E. Coli is comparatively simple, and there are many advantages to studying these prokaryotic cells in the fields of biochemistry and molecular biology. E. Coli has this simplicity and is relatively easy to propagate in a lab environment. Their genome has been completely sequenced and many things we know about DNA, protein synthesis, and gene linkage have been derived from studies regarding this particular organism. (Cooper)

In the first part of the experiment, we plated donor bacteria, which was chloramphenicol resistant, on a Nal plate. Because no donor bacteria would grow on a Nal plate, this was a way of ensuring that the sample of donor E. Coli bacteria was pure.

This experiment is about bacterial growth. We will demonstrate a bacterial growth curve using a closed system. Bacterial growth usually takes up to 12-24 hours to get an accurate result so we will be monitoring this growth between two classes. We also used different methods to determine bacterial growth as well as a few different calculations. One way of receiving data is by using a spectrophotometer where we will record the absorption at a given time to create the bacterial growth curve. We also used the plate count method after performing a serial dilution to calculate the actual cell density at different times given. By using this method we can count the population number of the same given and see the maximum cell density

100 μl of 10-5 and 10-6 dilutions of donor cells were each plated onto MacConkey (MAC) agar plates without streptomycin. 100 μl of 10-5 dilution of donor cells and 10-5 and 10-6 recipient were also plated onto MAC plates with streptomycin. 100 μl of 10-4 and 10-5 dilutions of the conjugation mixture cells were plated onto MAC agar with streptomycin. All seven plates were inverted and placed in a 37˚C incubator for about 24 hours. The bacterial colonies on each plate were counted the next day (colony counts seen in Table I).

In this lab experiment, students had to create a growth curve for E. coli. The E. coli growth curve would illustrate the progression of the population of E. coli a set time period. In this case, the growth curve depicted the population of E. coli over a 12-hour period. The growth curve for E. coli was created from the absorbance levels, the optical density(OD), recorded from the spectrophotometer.

In this laboratory experiment, we was introduce to an introduction to streaking and spreading of bacteria in agar plates such that single cells can be isolated from one another, each cell can reproduces to form a visible colony composed of genetically identical clones. Streaking and spreading bacteria is to obtain individual colonies is usually the first step in genetic manipulation of microorganisms.

Life on this planet began with microorganisms. Through millions of years microorganisms have found ways to successfully adapt and survive. These adaptations have created a wide biodiversity, allowing them to basically populate in all places. Why are these microbes so important? Because they shape the history of our world. Some microbes can be deathly to humans while some others are favorable, for example, bacteria that lives in the gut of both humans and animals and helps during the process of digestion (Alfred Brown & Heidi Smith, 2006). Understanding these interactions help scientists to find ways to protect humans from potential deathly pathogens. In order to observe microbes, microscope proficiency and microorganisms’ identification are crucial skills in a microbiology lab. During this laboratory session, samples of environmental and human organisms were inoculated into two different rich media and incubated to their according temperature. After this, appropriate use and calibration of the microscope was performed. Lastly, morphology and size of different species of bacteria, algae, fungi and protozoan were recorded.

This experiment was performed to test the hypothesis if LB nutrient broth, +pGLO and -pGLO Ampicillin, and Arabinose was placed in the E. coli plates, then there will be a significant growth in the newly transformed bacteria and it will possess the ability to glow under UV light. The measurements were recorded from the bent glass tube in each glass test tube. The transformation protocol tested for the newly possessed traits in E.coli bacteria. Throughout the experiment there were many probable reasons for failure. If the pipettes and sterile loop were not thrown out in between each use, a cross contamination could cause a miscalculation in the experiment causing the data results to fail. The hypothesis that was tested was validated due to the positive results with each experiment stating that newly transformed organisms due in fact pass on traits.

A sterile pipette was used to add 0.1ml of E. coli culture to the pH 3.0 tube. This was then repeated for the tubes at pH 7.0 and pH 9.The tubes were then incubated at 37oC for 48 hours. This was then repeated for saline culture of Saccharomyces cerevisiae but incubated for 72 hours at 25oC.