Introduction: Through the conduction of numerous experiments, the identity of two bacterial isolates was determined. The tested specimen was an unknown sample of a mixed culture of two different species of bacteria. The first step that was taken was obtaining a pure culture of each species of bacteria by isolating one species from the other. Once isolation was complete, the isolated cultures were tested using procedures and tests that had been performed during previous lab sessions. 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 previous experimentation.
Another purpose of this experiment is to stress the importance of knowing the identity of a microorganism. Knowing the species of microorganism present in a sample provides a stepping stone in determining the right path of patient treatment and/or environmental disinfection.
Isolation/Experimental Plan: The isolation of the two bacterial species was done by initially performing a T-streak using aseptic technique on a tryptic soy agar (TSA) plate. After incubation of the
An unknown bacterium was handed out by Dr. Honer. The appropriate tests were prepared and applied. The first procedure that was done was the gram stain. Under a microscope, if the gram stain is purple, the bacterium is gram positive, if the stain is red, it is gram negative. The next test was the fermentation tests for glucose, sucrose and
The purpose of this lab was to identify an unknown bacteria culture using differential tests. The identification of the unknown culture was accomplished by identifying the bacteria based on its specific metabolic characteristics and morphology. It is suggested that culture 11 is a sample of Enterobacter aerogenes.
A mixed culture of two unknown bacteria was provided by the instructor. The methods used for
The purpose of this study project was to carefully isolate and identify two unknown bacteria from a mixed culture. The ability to properly evaluate biochemical test results is also necessary for the identification to be successful. The goal was to apply all of the methods and techniques that have been learned in the microbiology laboratory course for the proper identification of unknown bacteria. A certain amount of bacteria that were used throughout the course were possible bacteria that could be found in a mixed culture. The bacteria that were identified in the mixed culture were Staphylococcus Aureus and Kocuria Rhizophila.
In a laboratory setting, it often becomes necessary to identify an unknown organism. In this experiment, researchers classified an unidentified bacterium based on its physical structure, colony morphology, optimal conditions and metabolic properties. A Gram stain using crystal violet, iodine, and safranin and a simple stain using methylene blue characterized the organism’s cell wall. Cultural behavior was classified by inoculating the organism onto nutrient agar and incubating it at 37° C for 48 hours, and observing its behavior, as well as using SIM medium to test for motility. Optimal growth temperature was
The purpose of this lab was to identify two unknown bacteria cultures using various differential tests. The identification of these unknown cultures was accomplished by separating and differentiating possible
This experiment was conducted to find the genus and species of an unknown bacteria prescribed by the lab teacher, which was unknown bacteria GA3 in my case. Identification of unknown bacteria techniques are used on an every day basis to figure out what type of bacteria it is and to find the best method of how to treat a patient with this bacteria (1). All five “I’s” of Microbiology were used in the testing for the unknown culture. Inoculation was used several times to put the unknown culture into agar plates or into biochemical test tubes. After Inoculation of these tubes or plates, they always were placed into the incubator for further growth and development. Isolation was used to make sure we got the correct bacteria we were testing for. After each further isolation, we gram stained the culture and inspected the culture under a microscope to further help in the identification process of the unknown bacteria. Multiple tests were done on the unknown culture to make sure we were confident in what kind of bacteria the unknown was.
There are many reasons for knowing the identity of microorganisms. The reasons range from knowing the causative agent of a disease in a patient, so as to know how it can be treated, to knowing the correct microorganism to be used for making certain foods or antibiotics. This study was done by applying all of the methods that have been learned so far in the microbiology laboratory class for the identification of unknown bacteria. The identification process can be completed with a series of deferential stains and biochemical tests. Creating a dichotomous key helps to limit the amount of biochemical tests done on an unknown organism and by observation
The main idea of this experiment was to correctly identify the unknown bacteria, #3. Identification of unknown bacteria yields multiple benefits in many different areas in the research of microorganisms. In this experiment I performed many different test dealing with things such as the presence of enzymes, fermentation abilities and different chemical reactions. Observations made from the tests were then compared to a gram negative unknown chart in order to identify the bacteria. Based off of my results and the chart, I concluded the bacteria #3 was the bacteria Escherichia coli. E. coli is most commonly found in the intestines of warm blooded organisms. Most E. coli strands are non pathogenic however, there are strands
As the flowchart shows, a series of tests were conducted to identify the unknown bacterium #65. Microscopic observation of the gram stain indicated a gram-positive coccus bacterium. S. epidermidis was used as the gram-positive control while E. coli was used as the gram-negative control. This observation led to the elimination of all gram negative and rod-shaped genera: Enterobacter, Citrobacter, Klebsiella, Escherichia, Pseudomonas, Serratia, Alcaligenes, Neisseria, Proteus, Salmonella, Shigella, Erwinia, Veillonella, Flavobacterium, Bacillus, Arthrobacter, Lactobacillus, Listeria and Kurthia (2). By performing the catalase test, it was determined that the bacterium was catalase negative and it did not produce bubbles. M. luteus and E. faecalis were used as positive and negative controls, respectively.
The purpose of this study was to identify the unknown bacterium using biochemical tests and various methods that had been learned from previous the microbiology laboratory class. Identifying the unknown bacterium was determined by separating and differentiating possible
In the world of microbiology it is vitally important to be able to discern the identities of microorganisms. Not only is it important in a lab setting but as well as in healthcare in general. Properly identify what strain of bacteria a person has will aid in the proper medicine and dose given. Throughout the semester we have learned about different types of bacteria and certain test that can clearly identify them. The purpose of this lab report is to identify a Gram-positive or Gram-negative bacterium. Using all the knowledge of procedures and lab techniques identify the unknown and discuss all the tests you performed.
The bases of this experiment was to discover the identify of the unknown from three possible specimens: Klebsiella pneumonia, Escherichia coli, and Enterobacter aerogenes. Utilizaing the T streak technique, the bacteria was isolated into pure colonies for further study. The Gram Stain method was used to identity the morhphology of the bacteria such as the shape and whether the bacteria was Gram positive or Gram negative. Biochemical test were also used to help identify the unknown bacteria. The biochemical test used was the Triple Sugar Iron Agar, Sulfur Indole Motility test, Methyl Red test, Voges-Proskauer test, Citrate test, Urease test, and the Gelatin test. After observing the morphology of the bacteria using the Gram Stain method and utilizing all the possible biochemical test, the bacteria was identified to be Enterobacter aerogenes.
A highly conserved gene will be used to identify a prokaryotic species isolated from the body. Fundamental lab techniques will be also explored and utilized, such as amplifying using PCR, cloning, and transforming the gene into a host cell. DNA electrophoresis and specific substrate plating will serve as analysis check points. The final product will be sequenced and compared to similar species to observe phylogenetic relationships.
Introduction: Through the conduction of numerous experiments, the identity of two bacterial isolates was determined. The tested specimen was an unknown sample of a mixed culture of two different species of bacteria. The first step that was taken was obtaining a pure culture of each species of bacteria by isolating one species from the other. Once isolation was complete, the isolated cultures were tested using procedures that had been performed during previous lab sessions. A gram stain was performed on the two isolates. The isolate which had tested gram negative was then tested for the presence of cytochrome C and lactose fermentation. For the gram positive isolate, cell shape was determined and a catalase test was performed.