The field of Microbiology allows scientists to identify microscopic organisms and their importance in the world. The purpose of this paper is to present differential media as well as common experiments along with utilization of the microscope to identify the unknown organism 52. One of essential technique for the laboratory identification or the unknown organism is the use of aseptic technique. Aseptic technique allows the transfer of organisms from one medium to another without contamination of the culture as well as the surrounding environment (1). This is an essential technique to master because contamination of the initial culture medium or the subsequent media can alter results. In order to identify the unknown organism 52 inoculation …show more content…
Positive control organisms provide expected results for a known organism while the negative control organisms provide no results for the selected experiment. The following sections discuss different materials and methods used to isolate and identify the unknown organism 52. Section II – Material and Methods Unknown 52 was initially grown in a Tryptic Soy Agar (TSA) plate, which is an undefined medium where the exact composition of the nutrient was not known. TSA plate was incubated for 24 hours at 35 oC which showed isolated colonies that were small, white, flat smooth margins, round, shiny colonies on the medium (1). Microscopic Examination Unknown 52 was observed under oil immersion using the bright-field light microscope 1000x magnification after conducting Gram stain technique. Escherichia coli (Gram negative rods) pre-prepared slide was the negative control while the Staphylococcus epidermidis (Gram positive cocci) pre-prepared slide provided the positive control in order to deduce the results of unknown 52. Unknown 52 exhibited purple color cocci which was consistent with S. epidermidis organism. It can be concluded that unknown 52 was a Gram positive cocci. The purpose of Gram stain technique was to identify the present or absence of thick peptidoglycan layer outside the cell (1). Gram positive organisms contain a thick peptidoglycan layer while Gram negative organism contains a thin
There are many reasons for identifying an unknown bacterium. The reasons range from medical purposes, such as determining if the unknown could cause ailments in living things or knowing what microorganisms are needed to make antibiotics. The experiment was done by applying methods in order to identify an unknown bacterium.
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.
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 I have been learned so far in the microbiology laboratory class for the identification of an unknown bacterium.
Many tests were completed on the unknown such as gram staining and inspection under microscopes to find whether the bacterium is gram positive or gram negative. Chemical resistance tests were also performed to see if certain chemicals affected the unknown growth or if it didn’t affect the bacteria at all. Each biochemical test
Table 3 shows Gram stain results that indicated C. Freundii as a gram negative bacterium in rod shapes scattered in singles and some in pairs. Each gram stain produced the same results. The Bartholomew and Mittwer method of endospore staining indicated that C. Freundii tested negative for endospore formation. Table 4 shows the biochemical test results of the unknown and the official test results for comparison.
A Dichotomous Key was studied to identify bacteria and their relationships. Some of the organisms at the end of the Dichotomous Key had viable characteristics that separate them from different groups, and those that did not students learned how to further classify them. A Dichotomous Key is used to narrow down the search for the unknown organism tested. It is organized by phenotypic characteristics of organisms and conducts a systematic way of identifying the other unknowns. In the lab students were given a tube labeled with a number. Instructions were given to conduct a Gram stain to begin the search followed by the use of a Dichotomous Key and photos as resources to carry out the search. Instructions read to isolate and identify the unknown bacterium with both differential and selective tests to positively identify the given unknown organism. Differential tests used specifically for this unknown microorganism was BEA (Bile Esculin Agar), which interpreted results by the hydrolysis of esculin when the media is blackened around
This is important in the medical field because identification of unknown bacteria can help treat a patient by knowing the contributing source of a disease. Also knowledge of different bacteria helped others make antibiotics used today. This lab was completed by using the methods learned thus far in identification of bacteria.
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
This experiment was given to us to utilized previous knowledge learned throughout the semester to identify a gram negative unknown bacterium. We had to first learn the difference between a gram negative and a gram positive organism. We started off with doing gram stains to determine whether it was positive or negative. Based on the gram stains, a gram positive stains purple and a gram negative stains pink. A gram positive stains purple because the cell walls is made of a thick peptidoglycan layer and doesn’t
21. The -DNA/LB plate had an even lawn of bacteria and looked off-white while the +DNA/LB/AMP plate had no bacterial growth.
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
Since microorganisms are not visible to the eye, the essential tool in microbiology is the microscope. One of the first to use a microscope to observe microorganisms was Robert Hooke, the English biologist who observed algae and fungi in the 1660s. In the 1670s, “Anton van Leeuwenhoek, a Dutch merchant, constructed a number of simple microscopes and observed details of numerous forms of protozoa, fungi, and bacteria” (Introduction to Microscopes, n.d.). During the 1700s, microscopes were used to further explore on the microbial world, and by the late 1800s, the light microscope had been developed. “The electron microscope was developed in the 1940s, thus
The purpose of this study is to identify four unknown organisms. The unknown organisms have been assigned randomly to six-research groups by Professor Hoffman. Each research group was provided two eukaryotes and two prokaryotes. The unknown organisms will fall into the following classifications: bacteria, algae, fungi, or protozoans. All living organisms are organized into one of three domains of life, Bacteria, Archaea, and Eukarya.
A great deal of cultural tests and physiological procedures were performed on the unknown before the conclusion of P. aeruginosa was made. The first test preformed was Gram’s staining which involves the use of crystal violet, Gram’s Iodine, Ethyl Alcohol, and Safranin. Gram staining is known as a differentiating stain, since it can determine the presence or absence of peptidoglycan in the cell wall. The unknown bacteria were Gram stain negative. After that the motility of the cell was tested using a hanging drop slide. The slide was examined, but the results were inconclusive due to the inability to make a clear distinction between motility and Brownian motion. This test was not
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