Microbiology Essay

Esherichia coli also known as E. coli is a bacterium that lives in your gut. (1). it was founded by Theodore von Esherich in 1888. There are many people that can get the bacteria. Also there are thousands of strands of E.coli. Six E. coli O157 outbreaks were identified during 2007. Four of the outbreaks involved foodborne transmission. (Eshericha Coli). Six Minnesota cases and one Wisconsin case with the same or closely-related PFGE subtype of E. coli O157:H7, and an additional Minnesota case of Shiga-toxin producing E. coli that was not culture-confirmed, attended the Minnesota State Fair in August. All but one of the cases showed cattle or visited the cattle

Osmosis is described in one of three ways when comparing more than one solution. The cell’s external and internal environment helps determine tonicity, which is defined as how the cell reacts to its environment. When the cell’s environment is equal in osmolarity to itself and there is no change, it is considered an isotonic solution. When the environment has a higher osmolarity, shrinkage occurs and it is considered a hypertonic solution. When the environment has a lower osmolarity, swellings occurs and it is considered hypotonic.

However, everybody who has contact with the patient or the environment is entitled to relevant information that will enable them to reduce the risks of transmission to

|EMB Agar | |Distinguishes bacteria that ferment |Dark blue colonies with|E. coli and P. |

The concentration of dissolved substances is greater in the extracellular fluid than in the cytoplasm. Hypertonic Solution Concentration of dissolved substances (solute) Concentration of water (solvent) What happens to an animal cells? Inside the cell Less Greater Outside the cell Greater Less Membrane

In this lab, the organism that we have been working with is the bacterium, Serratia marcescens. S. marcescens is a member of the Enterobacteriaceae family, and tends to grow in damp environments. S. marcescens is an ideal bacterium to work with in the lab because it reproduces quicker than other bacterium. This bacterium produces a special pigment called prodigiosin, which is red in color. The prodigiosin pigment is intensified when S. marcescens is grown at higher densities. During our experiment, temperature, pH, salinity concentration and oxygen requirements were tested on S. marcescens to measure their optimal growth and prodigiosin production.

Osmosis is the passive movement of water from an area of low solute concentration to an area of high solute concentration, normally across a membrane which prevents the movement of solvent. This is a process by which materials may move into, out of, or within cells. Osmosis doesn’t depend on energy provided by living organisms but is affected by the properties of the cell membrane. The rate of osmosis is dependent on such factors as temperature, pressure, molecular properties such as size and mass, and the concentration gradient. In osmosis, the relationship between a solute’s concentration outside of cell and inside of a cell is described in terms of the tonicity of the solution outside of the cell. A cell is in a hypotonic solution when the solute is more concentrated inside the cell and therefore water moves into the cell. In this solution the cell swells as water enters, this may continue until it ruptures or hemolyzes. In the reverse condition, the cell is in a hypertonic solution

Microorganisms are both beneficial and harmful. These microorganisms are important to humans because they play a role in the ecology of life, by decomposing wastes, both natural and man-made, such as creating nitrogen fertilizer at the root zones of certain crops. Other several pathogens that can cause serious harm, even immediate death due to the diseases or disease causing products they produce. Overall, microorganisms play an important role in life.

Abstract: Microorganism need to live in ideal conditions so they can grow. This experiment was performed to determine if there was a greater number of microorganisms in Winthrop lake than Winthrop wetlands. We determined this hypothesis because the lake was bigger. We also made the hypothesis that the pH level of the lake was going to be higher than the wetlands. We tested out the hypothesis by going out to Winthrop lake and wetlands and collecting samples of water. Back in the lab, we examined the samples under a microscope and recorded all the organisms we could find on Excel. Also, we tested the pH levels of the

As shown in the figure above, it is evident that V.natriegens grew faster when the Brain Heart Infusion (BHI) broth contained 250mM NaCl. The # of bacterial cells at each time point was measured following the equation given in the “How to generate a bacterial growth curve” supplemental material posted on D2L. (2) The data was then recorded in the table listed above. A growth curve graph was constructed using the data above which illustrated the differences between each of the different BHI mixtures. The graph was then used to determine the generation time of V.natriegens for each different environmental condition. In order to calculate the generation time (g) the mean growth rate (k) must be calculated. The formula to do this is posted in the supplemental material “How to generate a bacterial growth curve” on D2L. The k value calculated for each condition goes as follows:

Hospital acquired infections are one of the most common complications of care in the hospital setting. Hospital acquired infections are infections that patients acquired during the stay in the hospital. These infections can cause an increase number of days the patients stay in the hospital. Hospital acquired infections makes the patients worse or even causes death. “In the USA alone, hospital acquired infections cause about 1.7 million infections and 99,000 deaths per year”(secondary).

In osmosis, the flow of the water from or to a cell depends on whether the cell is immersed in a solution that is isotonic, hypotonic, or hypertonic to the solution. If the cell is isotonic to a solution, this means that the solute concentration of a cell and its environment is the same and therefore there will be no movement of water. If the solute concentration is lower than that of the cell, then water will flow into the cell, causing it to expand. If the solute concentration is lower than that of the cell then water will flow out of the cell, causing it to shrink.

2. Introduction: Each student was given unknown bacteria and was instructed to perform a variety of experimental tests that would help to identify their bacteria. During the process of identification, the unknown bacteria was added to many different testing medias using aseptic technique. They are as follows: lactose fermentation on eosin methylene blue (EMB), TSI (Triple Sugar Iron agar), Phenol red sucrose, the SIM test, H2S by SIM, IMViC (indole, motility, voges-proskauer, and citrate), Urease (urea broth), PDase (Phenylalanine Deaminase), Lysine Decarboxylase, and Ornithine Decarboxylase. Colonial morphology on EMB was used to

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.

The law proves that natural selection is necessary for evolution to occur ("SparkNotes: population genetics," 2014). The conditions set up by the Hardy-Weinberg Law allow for variability (the existence of different alleles) and inheritance, but they eliminate natural selection ("SparkNotes: population genetics," 2014). The fact that no evolution occurs in a population meeting these conditions proves that evolution can only occur through natural selection ("SparkNotes: population genetics," 2014). The Hardy-Weinberg Law allows us to estimate the effect of selection pressures