Comparing The Cellular Morphology Of Table 2

During the purification section of this lab, the LB/amp/ara agar plate was examined for well-isolated green colonies and the LB/amp plate was observed for white colonies with space between each other. These colonies were circled on the outside of the plates using a marker. Next, two 15 milliliter culture tubes containing 2 milliliters of nutrient growth media were obtained and labeled “+” and “-“. Using a new inoculation tube, the circled colonies from each plate were scooped out and immersed in their respective culture tubes. Once the bacteria was mixed into the solution, the tubes were sealed and placed horizontally into the 32⁰ incubator for 24 hours.

Over a two week period, eight prepared types of test media were provided to identify the assigned unknown mixed cultures. Not all of these tests were performed on every culture, as some were used only for gram positive or gram negative bacteria. The tests performed and what constituted a positive or negative test are as

The next step of the project included preparing a Gram stain to discover the cell shape, arrangement, and if the bacteria is gram positive or

For this experiment, I utilized unknown number three which I later identified as Staphylococcus epidermis. I concluded that the unknown organism was Staphylococcus epidermis based on numerous tests performed in the laboratory which I will discuss in detail throughout this paper. One of the first tests performed was the Gram Stain. The Gram Stain

Before plating the strains on agar plates, dilutions of the three strains of cells were prepared with LB broth.

The purpose of this project was to identify the identities of two unknown bacteria in a mixed broth culture by using several separation methods. To separate the organisms, a four-way streak plate technique was used to isolate the two unknown bacteria into separate visible colonies. Then after each colony were clearly isolated; the two unknowns were processed through Gram staining test to determine the Gram stain and morphology. After Gram staining, a carbohydrate test was performed on each unknown to determine if it had glucose, sucrose, or lactose fermentation. The results of the sugar test help determining which biochemical test should be performed next. The Gram positive organism was tested through a carbohydrate fermentation test, then further tested to confirm its identity through an indole and catalase test. The Gram negative organism was tested through carbohydrate fermentation test, then further tested to confirmed its identity through an indole, and TSIA test. After running four biochemical tests, the results conclude that the Gram positive unknown was Staphylococcus aureus. S. aureus was identified based on the fermentation results of the glucose test, negative indole test, and a positive catalase production. S. aureus is a Gram positive circular shaped bacterium that is very common in the U.S and is normally found in the nose, respiratory tract, and on the skin. This bacterium is usually the most common cause of infections after injury or surgery.

Preliminary studies help identify Genus species of bacteria. Two different preliminary study pathways must be used since two different pathogens were found in the sample. A dilution and a quadrant streak are the ideal methods to separate pure cultures of bacteria. MacConkey Agar and CAN (MAC) is a selective media that is used for the cultivation of gram negative bacteria. (PEA) is a selective media that is used

Name this Procedure  Identify the two types of bacteria present by shape and gram stain. In a gram stain what is the primary stain?

The streak plate method is a rapid qualitative isolation method. The techniques commonly used for isolation of discrete colonies initially require that the number of organisms in the inoculums be reduced. It is essentially a dilution technique that involves spreading a loopful of

From last week’s test, we achieved pure cultural characteristics from the two slants we made. The growth we saw on the agar slant that contained the yellow specimen was a soft, smooth, yellow growth. The growth we saw on the beige specimen was a thin, even, beige growth. Both cultural characteristics were achieved in the appropriate categories. The categories we were looking for contained abundance of growth, pigmentation, optical characteristics, and consistency. Today we will be preparing two bacterial smears from each specimen and Gram staining them. The reason we are conducting this test is to differentiate between two principle groups, gram positive and gram negative and to further know if a pure culture from both organisms was achieved. This is important for classification and differentiation of microorganisms. The Gram stain reaction will help us tell the difference of the chemical composition of bacterial cell walls. The Gram stain procedure uses four different reagents such as crystal violet, gram’s iodine, ethyl alcohol, and safranin. Before the Gram stain is performed we must make two bacterial smears of the two specimens. We placed one loop of distilled water on a clean slide aseptically. He transferred the specimen from the agar slant that contained the yellow growth and placed it on the slide with the water and gently mixed it together in a circular motion approximately the size of a nickel. He let the smear air dry for one minute and gently heat

5 The test microscope slide was composed of a drop of B. subtilis solution placed on the left as the Gram-positive control, a drop of a solution with unknown in the middle, and a drop of E. coli solution on the right as a Gram-negative control. The slide was allowed to dry and the samples were heat fixed with a Bunsen burner. The samples were then stained with first crystal violet for one minute. After the rinsing the stain, the mordant, Gram’s iodine, was added for one minute and rinsed. A 95% ethyl alcohol/acetone solution was then applied and rinsed to de-stain the samples. Finally, Saffranin was added as the counterstain for one minute and then rinsed. Bright field microscopy, using 1000X magnification and oil immersion, was conducted to visualize first the controls, and if those results were accurate, the unknown. The three samples were observed for stain color to determine Gram classification, as well as shape and arrangement to further classify the

This laboratory experiment’s objective was to take a pure culture and isolate it from a mixed culture. The other part of the objective was to ascertain what species of bacteria that the pure culture was. The hypothesis made stated that so long as lab protocol was followed, the unidentified culture would be positively recognized/identified. An isolated pure colony of the unknown culture was obtained using the quadrant streak plate method. Afterward, the culture was Gram stained, and the results showed that it was Gram positive. Motility tests were done on the unknown using a filter paper bridge on a petri dish that contained TTC with agar. The unknown was revealed to not be motile, which meant that it did not possess flagella. The last test done was to learn the metabolic capabilities of the unknown bacteria. There were tests done for citrate utilization, the mixed fermentation pathway, catalase presence, carbohydrate fermentation in mannitol, lactose and glucose, urease production and the butanediol fermentation pathway in order to better identify the unknown bacteria. The results from each of the metabolic tests in conjunction with the motility and Gram staining tests were ultimately compared to results from database containing many different kinds of results from various bacteria. The unknown from the mixed culture was identified as Staphylococcus

Staphylococcus, Enterococcus and Streptococcus is considered as a leading cause of many diseases. They are considered different due to their morphology. The Staphylococci and Streptococci acquires a round, spherical cell shape. On the other hand, the arrangement of cells is considered different for both the organisms. For instance, Staphylococcus aureus is a gram-positive, cluster-forming cocci and a nonsporeforming facultative anaerobe which is found in grape like structures. Enterococcus is also gram-positive cocci with short chains and are considered to be facultative anaerobes. They can grow at a temperature range of 10-45 degrees Celsius. Enterococcus is acknowledged as the leading cause of the nosocomial infections. The golden

The colonies were smooth, translucent, and had a white brownish color. The Gram stain resulted in Gram positive cocci. After the Gram stain was completed, the bacteria were streaked on a Mannitol-Salt Agar plate and a Catalase test was performed. After these test were completed a Phenol Red Dextrose Fermentation tube was inoculated, and a SIM Tube inoculated.

Each mixed culture that was tested had one gram positive and one gram negative bacterial species. The possible species of bacteria that could have been isolated from the mixtures included the following: Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Salmonella enterica, and Pseudomonas aeruginosa. The identities of the unknown species were determined through comparing the experimental data against data acquired from earlier experimentation.