E. Coli Bacteria Lab Report

An endospore is a dormant of a bacterial cell. It is a non-reproductive structure that ensures survival of a bacterium through stressful environmental conditions. Unknown #76, using aseptic technique, was inoculated to a nutrient sporulation medium (NSM) plate. This concerns a selective medium that increases the initiation of endospore production. A spore-former would have green-pigmented endospore cells when looked at under the microscope. From the growth on the NSM, I smeared it aseptically to a wet slide. Slide was then left to be air-dried for about 10 minutes. It was important to heat fix the slide using a micro incinerator. The succeeding steps had to be taken with caution because the primary stain, malachite green, is toxic. Under the hood, the slide was covered with a properly cut size of paper towel. The slide was then stained and left to steam with malachite green. It was continuously followed up by applications of the stain so it may remain moist for 10 minutes. The slide was then rinsed and safranin was again used as a counterstain. Using oil immersion objective lens of the microscope, unknown #76 had only reddish-pink cells without any signs of spore formation. Thus the given unknown is a non-spore former. Bacillus subtilis was used for positive control and Escherichia coli for negative control for endospore

Tn 4351 was originally isolated from bacteroides fragilis [30] . The transposon was successfully introduced into Cytophaga succinicans, Flavobacterium meningosepticum, Flexibacter canadiansis, Flexibacter strain SFI and Sporocytophaga myxococcoides by conjugation [25]. Tn 4351carries two antibiotic resistance gene. One of the codes for resistance to erythromycin and clindamycin which is expressed in bactroides but not in E.Coli. The other gene codes for resistance in tetracycline and is expressed in aerobically grpwn E. coli, but not in anaerobically grpwn E. coli or in bacteroides. The transposon of Tn4351 was originally detected in E. coli which carried an unstable chimeric plasmid, pSS-2. The mobilization of pSS-2 from onestrain of E. coli

A mutation is a heritable change that is passed from the mother cell to progeny cells. Mutations may lead to good, bad or neutral phenotypic changes in the organism. They may occur spontaneously as in random DNA replicative errors or may be induced by mutagenic chemicals or radiation. Besides mutations, another way that bacteria achieve gene diversity is through the three known mechanisms for intercellular gene transfer. They are transformation, a genetic process which free DNA is incorporated into a recipient cell, transduction, a process which bacterial virus transfers DNA to another cell, and conjugation, a form of horizontal gene transfer which requires cell-to-cell contact.

A milk-based, litmus broth tube is incubated and observed after 48 hours. Observations include lactose fermentation without gas as well as with gas, the reduction of litmus, casein protein coagulation and casein and protein hydrolysis. These characteristics were all determined based on the color of the solution and the production of a curd, the curds density and the production of a gas. To determine the density of the curd, the tube was slightly turned to see rather or not it was mobile or concentrated towards the bottom.

Genetic engineering is changing the DNA code to express different traits. A plasmid is a circular piece of DNA that contains important genetic information. Recombinant DNA is the product after inserting your desired genes. The genes we hoped to insert in the pGLO lab were the GFP gene and the ampicillin resistance gene. GFP was needed so that we would tell if the ampicillin resistance gene had been properly placed when the bacteria glowed under a UV light. The purpose of this lab was to perform a procedure known as genetic transformation which allowed us to genetically engineer E. Coli to be ampicillin resistance.

Introduction: Transforming a gene or genetic information from one organism into another with the hopes that if done successfully the organism with the new DNA will be given new traits is a method known as genetic transformation (Rafter). Genetic transformation is used quite frequently in today’s world, form medicine to agriculture.

Bethany Brookshire, the author of the article “New gene resists our last-ditch drug” found in the Society for Science & the Public, invoked fear and urgency in teen readers fascinated with biology and health. Throughout her article, Brookshire establishes that doctors, farmers, and everyday citizens should be cautious in the use of antibiotics and use methods to limit the spread of harmful bacteria worldwide. She gains her readers’ attention and trust by quoting information from several scientists in different fields and from different parts of the world. Although her syntax was rigid and overly simplified, Brookshire connect to the teen readers ******

In the laboratory, identification of an unknown bacterium is often necessary. In the lab, a random sample consisting of three different bacteria was selected. The sample contained one gram-positive, one gram-negative paracolon, and one gram-negative coliform. The purpose of the experiment is to identify each of the three species that the mixture contained. After receiving an unknown mixture, the sample was streaked for isolation onto TSA, blood agar, and MacConkey plates. Each plate serves as a first step to identify the unknowns. The TSA (tryptic soy agar) can be used to do a gram stain, which differentiates gram-negatives from gram-positives, based on the structural make up of the cell wall (Carson, 2015). The blood agar plate is used to test for hemolytic activity, which is useful for distinguishing gram-positives. A MacConkey plate is selective by inhibiting the growth of gram-positives and differential due to the fermentation of lactose by certain gram-negative species.

How do Green Bacteria overcome the low light conditions at which they are often found?

Colistin is an antibiotic that works best against Gram-negative bacteria. It works by binding to LPSs (lipopolysaccrides) and phospholipids in the outer cell membrane of the bacteria. This, in turn, disrupts the outer cell membrane by displacing cations and leaking the intracellular contents, combining it with outer cellular contents, causing the bacteria to be unable to differentiate the bacteria’s intra and outer cellular contents from one another. This ultimately leads to the bacteria’s death.

The putrid smell of Escherichia coli is one that is immediately identifiable to the few lucky individuals who recognize its scent. It is also an aroma with which I became intimately sensitive to as I shuttled petri dishes of the bacterium in and out of an incubator. While my classmates shied away from the task of handling the pungent bacteria used in our recombinant DNA experiments, I took to the task eagerly, anything that would take me one step closer to my goal of researching. I had the opportunity to learn about lab techniques and cutting edge biology concepts the summer before my junior year, in an extracurricular biotechnology class at Northwestern University’s Center for Talent Development. The class, a three week crash course in the

Biochemical tests are the tests used for the identification of bacterial species based on the differences in the biochemical activities of different bacteria. Bacterial physiology differs from one species to the other. These differences in carbohydrate metabolism, protein metabolism, fat metabolism, production of certain enzymes and ability to utilize a particular compound help them to be identified by the biochemical tests. Gram’s stain was originally devised by histologist Hans Christian Gram in 1884. Gram-positive bacteria stain purple, while Gram-negative bacteria stain pink when subjected to Gram staining. Approximately 60-90% of the Gram-positive bacterial cell wall is made up of peptidoglycan and interwoven teichoic acid, while only

This paper will specialize on a specific type of bacterial foodborne illness caused by the bacteria Escherichia Coli. E. coli was discovered by Theodore von Escherich in 1885. E.coli is a natural found bacteria that lies throughout the intestinal tract of warm blooded animals and comes in many forms only one of which is deadly. This form is E. coli 0157:H7 which can be caused by direct exposure to fecal matter to kill this rouge E.coli the contaminated material must be cooked at 160 degrees Fahrenheit or higher. In the United States every year 73,000 people are afflicted with this rouge E.coli in which an average of 61 people die. One other form of E.coli that can be detrimental to your health is the Shiga producing E.coli 026 (STEC 026)

The term fermentation refers to the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat (wikipedia). Sugars are converted to ethyl alcohol when fermentation happens. In this experiment we determined if yeast cells undergo fermentation when placed in a closed flask with no oxygen. Glucose and yeast are mixed together in a closed flask and allowed to incubate for about one hour. Then, tests are performed to determine if the products of aerobic and anaerobic respiration are present in the flasks.The citric acid cycle consists of a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins into carbon dioxide and chemical energy in the form of ATP (Biology). The tests detect the presence of carbon dioxide and ethanol. Carbon dioxide should be present irrespective of the type of respiration taking place, but ethanol is present only if fermentation has occurred. Another factor that can indicate whether fermentation occurred or cellular respiration occurred is the amount of glucose utilized during incubation.Fermentation uses more glucose because the process of fermentation is much less efficient than cellular respiration in terms of energy production per molecule of glucose used. The open flask (control) and the closed

Prokaryotic organisms normally have a cytoplasmic membrane, cell wall, and sometimes a capsule. Bacterial cells are most commonly either coccus or bacillus in shape. The cell wall is either Gram positive or Gram negative. When the cell is Gram negative, the cell has an extra layer of lipopolysaccharides. The Gram positive has a thick layer of peptidoglycan. Bacteria usually have capsules, but archaea rarely have one. Inside the prokaryote is cytoplasm and a nucleoid. The nucleus is not enclosed inside of a membrane in prokaryotes. The cell may have appendages to adhere to certain surfaces or for motility. The prokaryotic cell is smaller than the eukaryotic cell and has different qualities that make the cell less complex than a eukaryotic cell.