This statement if for the MU PREP program to further elaborate on my laboratory experiences.
My very first laboratory experience was with Dr. Rolf Joerger at the University of Delaware’s Townsend Hall food microbiology laboratory through the Nation Science Foundation - EPSCoR Progrram, there I also helped out some other principle investigators around the department occasionally as need. I came in, in the midst of ongoing research pertaining to the acid tolerance resistance of salmonella serovors associated with food borne illness and contamination in the food industry.
We investigated a conservative portion of salmonella’s chromosome that possessed similar homology with E.coli’s chromosome that entailed a genomic region referred to as the
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At which we conduct research inspecting the microbial loads of fresh produce items (Lettuce heads, and tomatoes) from different areas of demographics within Tallahassee. Using statistical analysis of the total plate counts, we confirmed that there was no significant contamination difference between locations. This occurred during the Fall 14’ Spring 15’ academic semester, I was also TA and help with labs classes and various odds and ends. And minutely, I independently worked on cellular cultures of Agaricus bisporus mycelium in vitro curtsey of …show more content…
The first obstacle being the actual generation of the L.m. biofilms. With ample amounts of literature review and assistance we managed to merge multiple facets of different articles to develop a protocol that produced biofilms. Afterwards, the problem of quantifying the formation of biofilm plagued my project. I was using Crystal-Violet and colorimetric assays in attempt to quantify the biofilms but, unfortunately this reagent imparted too much error in our results due to undifferentiating between viable and non-viable cells. I then proposed we use a flurometric assay that would further confirm the viability and activity of biofilm. Using his prior experiences with flurometric techniques Dr. Rolf suggested we use the reagent resazurin. To summarize the protocol the starter cells were incubated overnight then diluted into microtiter plates where they were left to adhere to well wall at specified times depending on sample, next inoculated microtiter plates underwent a series of washes with PBS buffer to remove free living cells and unattached cells, followed by air drying and staining with resazurin, lastly measurements were taken at 30 minute increments for a total of two hours at the corresponding wavelengths to quantify activity of resazurin, this was performed at 48hr, 72hr , 96hr, various culturing time
The first day an unknown sample was assigned to each group of students. The first test applied was a gram stain to test for gram positive or gram-negative bacteria. The morphology of the two types of bacteria was viewed under the microscope and recorded. Then the sample was put on agar plates using the quadrant streak method for isolation. There were three agar plates; one was incubated at room temperature, the second at 30 degrees Celsius, and the third at 37 degrees Celsius. By placing each plate at a different temperature optimal growth temperature can be predicted for both species of bacteria.
In this lab project, the microbiology students were given 2 unknown bacteria in a mixed broth each broth being numbered. The goal of this project is to determine the species of bacteria in the broth. They had to separate and isolate the bacteria from the mixed broth and ran numerous tests to identify the unknown bacteria. The significance of identifying an unknown bacteria is in a clinical setting. Determining the exact bacteria in order to prescribe the right treatment for the patient. This project is significant for a microbiology students because it gives necessary skills to them for future careers relating to clinical and research work.
Cu (aq) + 2NO3 (aq) + 2Na+ (aq) + 2OH- (aq) → Cu(OH)2 (s) + 2Na+ (aq) + 2NO3(aq)
The results of this experiment are shown in the compiled student data in Table 1 below.
The first step to the unknown is selecting an actual organism. The best way to select a culture is based on a high-quality distribution. Equally important, shaking up the broth tube facilitates in the distribution. Upon selection, a gram check for purity is performed. Step by step instructions for this procedure can be found in Benson’s, Microbiological Applications p. 99. Furthermore, an aseptic technique must be performed for this test and the entire tests following the unknown. The purpose of this test is to differentiate between gram positive and gram-negative bacteria. The key indicator of gram-positive bacteria is a purple stain and a pink stain for gram-negative bacteria. A slide is viewed with a microscope under oil immersion. Equally
The purpose of this project was to identify unknown bacteria species from a mixed culture. The two unknown species were initially plated onto Tryptic Soy Agar (TSA), Eosin Methylene Blue (EMB), Mannitol Salt Agar (MSA), and blood agar plates to distinguish between the two different bacteria using colony size, color, shape, and growth characteristics. By identifying and inoculating the differing types of colonies, the two unknown bacteria were purified and able to be tested
Many say that history repeats itself, and throughout history, the spread of food-borne diseases has been constantly threatening humans. Salmonella, a disease which attacks numerous people a year, has returned, infected, and put people under panic of what they are eating. According to Foodborne Diseases, it is stated that “Salmonella comprises a large and diverse group of Gram-negative rods. Salmonellae are ubiquitous and have been recovered from some insects and nearly all vertebrate species, especially humans, livestock, and companion animals” (Gray and Fedorka-Cray 55). Because of the flexibility and the ability to reproduce rapidly, this infamous disease still remains as one of the most common threats in our society as well as an unconquerable problem that humans face these days.
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test.
The question that was proposed for investigation was: Can the theoretical, actual, and percent yields be determined accurately (Lab Guide pg. 83)?
Multiplication of attached organisms leads to confluent growth and biofilm formation. Adherent bacteria synthesise extracellular polymers.
Biofilms are defined as complex aggregates of microorganisms which are interlinked and secrete extracellular slime, which forms the matrix for the films. The extracellular slime is chiefly made up of polysaccharides. Biofilms are usually irreversibly attached to a surface, in that once a biofilm is attached to a surface, it is quite difficult to remove. Mineral salt crystals, clay, silt particles, etc. are also sometimes present within the biofilm matrix (depending upon the surroundings). The majority of biofilms found in the environment are either phytoplanktonic or bacterial (Donlan, Sept 2002).
Salmonella enterica typhi (typhoid fever causing bacteria) are parasites with no other known living environment outside of humans (Pike, 2014). Typhoid has the ability to cause large outbreaks and the Centers for Disease Control and Prevention (CDC) has classified Salmonella species with other food safety threats as high priority potential bioterrorism agents (Baggier, Burwen, Haber, & Ball, 2004). Salmonella enterica typhi is one of three species of the Salmonella genus. Typhoid gets its name from Typhos, which means smoke, or to cloud, or vapor. It was thought to be transmitted through a “cloud of sickness called miasma” (Pike, 2014). When someone recovers from typhoid fever, about 3-5% become carriers o...
Biofilms are formed by a six step process. First is a reversible process, when an organic monolayer(made of polysaccharides or glycoproteins) absorbs to the surface, altering the chemical and physical properties of the surface. This makes the surface more conditioned and increase the chance that planktonic bacteria will attach. Secondly, also a reversible step, is when the free-floating or planktonic bacteria encounter the conditioned surface, and some attachment of the bacteria may occur. The third step is when the bacteria is left attached too long, then an irreversible attachment occurs. F...
The duration of the experiment should be increased as the thermal death times of B. subtilis at 60, 70 and 80°C were unable to be determined within 110 minutes. The duration can be increased to 180 minutes so as to better investigate its thermal death times. If the presence of bacterial growth was still observed after 180 minutes of exposure, it can be assumed that B. subtilis is able to survive well in that temperature. An exposure time of one day can be carried out to confirm this assumption.
During my time as a student I have been able to develop the way I learn and interact with others to a degree that has also helped me to mature into a better person. I have come to believe that this maturity will help me to develop into a better thinker as well, one that has the patience to listen and take consideration of what others have to say. I consider the act of learning a two way avenue that has to be taken seriously. It is one that involves the teacher, and the protégé. It has been, and will continue to be, my absolute goal as a student to become a diligent protégé and acquire all of learning my teachers have set in front of me. The way each of them have helped me to think about how my actions, and the way I choose to study my lessons and develop as a student, has made a tremendous impact on my life. This impact is one that I will carry into the future as I myself advance in my professional studies.