Escherichia Lab Report

AIM – The aim of the experiment is to determine the relative effectiveness of several anti-microbial substances on developing pathogens. (E. coli)

The titer of recombinant phage was determined with the number of plaques on the E.coli K plates and the titer of total phage progeny was determined with the number of plaque on the E.coli B plates.

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

On August 19th, 2015 this experiment was performed, by 6 separate lab groups.The experiment began by measuring 1 Ml of E. coli into a pipette and pump, then placing the bacteria into a culture medium. The E. coli and medium were then swirled together for a period of 15 minutes, until completely mixed. This mixture was then poured into a petri dish and allowed to solidify for 45 minutes. After the 45 minute solidification time, 5 small paper disks were inserted into the dish. 4 of the disk contained treatments of antibiotic and 1 was left untreated. The

coli bacteria affects bacterial growth and gene expression in several environmental conditions. To begin, two micro test tubes were labeled; one with +pGLO and one with -pGLO. 250 µl of transformation solution was added to each microtube, with use of a sterile pipette. Afterwards, the pipette was placed in a bleach solution and the microtubes were placed into the foam rack and onto crushed ice. Next, a colony of bacteria was removed from the starter plate with a sterile loop and thoroughly mixed within the +pGLO microtube. This step was repeated with a second sterile loop and the -pGLO microtube. After their use, all loops were placed in the bleach solution for decontamination and the microtubes were returned to the foam rack and ice.

After the trials were completed, a 1:9 bleach to water solution was poured on top of the prepared agar plates. This safety precaution was used to kill the bacteria in preparation of disposal of the agar plates. After the bleach solution was applied to the agar plates, the solution stayed on the agar plates for approximately 5 minutes. The bacteria on the agar plates turned a yellow color after the five minutes and were disposed of. Each safety precaution implemented in this experiment was to ensure the safety of the experimenter, and other

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)

E. coli or Escherichia coli is a prokaryotic cell found the in lower digestive track of mammals and other warm blooded animals. E. coli is an easy bacteria to work with as it doubles quickly and is relatively easy to grow, millions of cells can be grown in several hours. E. coli is an ideal bacteria in the lab because it does not require its temperature to be too hot, too cold, or too precise. A general warm temperature is perfect for this bacteria. E. coli is also easy to care for it does not need a specific type of nutrient, in a lab setting it can be feed any agar, making the bacteria over all cheaper to care for. Strains of E. coli can also operate in aerobic or anaerobic environments.

CDCgov: Escherichia coli (E. coli) [Internet]. Centers for Disease Control and Prevention; c2014-2015 [cited 2015-11-08]. Available from

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

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.

The purpose of the two experiments was to determine the fundamental effects that temperature has on the growth and survival of bacteria. During the first experiment five different bacterial broth cultures of Escherichia coli, Pseudomonas fluorescens, Enterococcus faecalis, Bacillus subtilis and Bacillus stearothermophilus were individually incubated at temperatures of 5, 25, 37, 45 and 55°C for one week in an aim to distinguish the effect temperature has on growth and survival of the five different species. After one week they were observed for distinguishable changes by the turbidity showing an indication of bacterial growth, or the clarity an indication of no survival.

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 fresh pipette was used to transfer 0.5ml of broth culture of E. coli, to be inoculated, into a tube of molten agar previously boiled to drive off oxygen. The tube was then rolled to distribute the bacteria and allowed time for the agar to harden. The tube was incubated at 37oC for 48 hours. The procedure was repeated for broth cultures of the bacterium Clostridium sporogenes and B. Subtilis.

Live Lactobacillus casei Shirota strain, cultured and tested in our laboratory, is added to the tank. The temperature of the tank is then reduced until the contents are at 37°C (body temperature). The solution is allowed to ferment in the tank for 6-9 days or until the numbers of Lactobacillus casei bacteria reach their ideal concentration.