Introduction
The purpose of this experiment is to appreciate the identification process and recognize its importance in various settings such as clinical, research and industrial. The identification of unknown microbes may be critical when developing an effective treatment method. For example, when an individual is ill and the physician must treat them, they must first identify the microbe infecting the patient in order to efficiently prescribe the correct treatment. Without following scientific processes to identify the microbe physicians are left with a less effective, trial-and-error treatment plan1. This will cause the prescribed method of treatment to only be ‘guess’ conduct1. Another reason for the requirement of identification process
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“The analysis of food for the presence of both pathogenic and spoilage bacteria is a standard practice for ensuring food safety and quality.2” One method used in order to detect these types of microbes is called the conventional method. It is a very inexpensive, and sensitive method that can give numeric and quality data on the amount and nature of the microorganisms existing in the food sample. Although this method is very inexpensive it does require several days before being able to see the colonies. Not only is it a time sensitive procedure but it is also labor intensive consisting of, “culture medium preparation, inoculation of plates and colony counting.2” Though this is a beneficial method, it is very time sensitive. Additional prompt methods are needed in the food industry in order for constructiveness. In exercise 14, the identification process of the unknown microbes, four different techniques were used in order to identify the unknown microbes. The first crucial step in the procedure was finding pure culture. The microbes must produce separate colonies in order to use them in the next step known as gram staining. The gram stain procedure classified whether the microbes were gram positive or gram negative. The microbes developed unique …show more content…
The purpose to identify the two microbes by using numerous different techniques was accomplished. Not only were the microbes identified but the appreciation for the identification process has grown. The crucial role identification process plays in society is more apparent and fundamental than it appears. Identifying bacteria can be crucial with the well-being of humans and their consumption. Not only their well-being but identifying bacteria is a type of preventative measure to stop death or illnesses before the bacteria spreads. After gram staining it appeared that both microbes were purple therefore both gram negative. These results gave off the illusion that both unknown bacteria were able to retain the primary stain. This was an error due to over staining that occurred in the process of gram staining specifically with microbe B. Luckily, the two were distinguishable after the Lactose test results were presented. This is because lactose tests for the production of acid and gas. The results for microbe A were negative meaning acid production did not occur with this unknown microbe and therefore had to be B. sub. On the other hand, microbe B resulted in the assembly of both gas and acid production. Thanks to this result it was apparent that the unknown microbe B could not be gram positive. Gram negative organisms do not produce bubbles when tested with Lactose broth. This gave the indication that
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. Materials and Methods/Results Upon receiving the Microorganism (M.O.) #16, I prepared a slide by cleaning and drying it. Then, using a bottle of water I placed a sterile drop of water on the slide and used an inoculating loop, flame sterilized, I took a small sample of the unknown growth in my agar slant and smeared it onto the slide in a dime sized circle and then heat fixed it for ten minutes.
Each test that was used in the lab for the unknown bacteria had been performed on many different bacteria and shown that each test has different results depending on the bacteria given. The first test, the Gram stain, confirmed that the unknown bacterium was a gram negative bacilli. After performing the remainder of the tests and comparing them to the twelve negative bacteria that it could be out of it was basically a process of elimination. Basically looking at all the results and seeing which tests separated positive verses negative results the most. After reviewing all of the tests the first test that stuck out besides the gram stain was the lactose fermentation, followed by the citrate utilization test and then by the indole test. The lactose fermentation test eliminated seven of the 12 bacteria. From the five bacteria left the citrate utilization test eliminated who more of the bacteria, and last the indole test eliminated two of the three bacteria left leaving only one bacterium left. After comparing the results to the results of the 12 tests and separating which tests were positive and negative for each it was obvious that the bacteria had to be Shigella
After 5 days of growth each slant was tested using the gram staining technique to confirm the complete isolation of the bacteria. Both isolations were completely successful. Then each sample of bacteria was subjected to a series of tests for identification.
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.
The purpose of this study is to identify an unknown bacterium from a mixed culture, by conducting different biochemical tests. Bacteria are an integral part of our ecosystem. They can be found anywhere and identifying them becomes crucial to understanding their characteristics and their effects on other living things, especially humans. Biochemical testing helps us identify the microorganism present with great accuracy. The tests used in this experiment are rudimentary but are fundamental starting points for tests used in medical labs and helps students attain a better understanding of how tests are conducted in a real lab setting. The first step in this process is to use gram-staining technique to narrow down the unknown bacteria into one of the two big domains; gram-negative and gram-positive. Once the gram type is identified, biochemical tests are conducted to narrow down the specific bacterial species. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
After the end of the experiment the unknown 10 sample was Staphylococcus epidermidis. Came to this conclusion by first beginning with a Gram Stain test. By doing this test it would be easier to determine which route to take on the man made flow chart. Gram positive and gram negative bacteria have a set of different tests to help determine the unknown bacterium. Based on the different tests that were conducted in lab during the semester it was determined that the blood agar, MSA, and catalase test are used for gram positive bacteria while Macconkey, EMB, TSI, and citrate tests are used for gram negative bacteria. The results of the gram stain test were cocci and purple. This indicated that the unknown bacteria were gram positive. The gram stain test eliminated Escherichia coli, Klebsiella pneumonia, Salmonella enterica, and Yersinia enterocolitica as choices because these bacteria are gram negative. Next a Blood Agar plate was used because in order to do a MSA or a Catalase test there needs to be a colony of the bacteria. The result of the Blood Agar plate was nonhemolytic. This indicated that there was no lysis of red blood cells. By looking at the plate there was no change in the medium. Next an MSA test was done and the results showed that there was growth but no color change. This illustrates that the unkown bacteria could tolerate high salt concentration but not ferment mannitol. The MSA plate eliminated Streptococcus pneumonia and Streptococcus pyogenes as choices since the bacteria can’t grow in high salt concentration. Staphylococcus aureus could be eliminated because not only did the unknown bacteria grow but also it didn’t change color to yellow. Lastly a Catalase test was done by taking a colony from the Blood Agar plate...
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
The purpose of this laboratory is to learn about cultural, morphological, and biochemical characteristics that are used in identifying bacterial isolates. Besides identifying the unknown culture, students also gain an understanding of the process of identification and the techniques and theory behind the process. Experiments such as gram stain, negative stain, endospore and other important tests in identifying unknown bacteria are performed. Various chemical tests were done and the results were carefully determined to identify the unknown bacteria. First session of lab started of by the selection of an unknown bacterium then inoculations of 2 tryptic soy gar (TSA) slants, 1 nutrient broth (TSB), 1 nutrient gelatin deep, 1 motility
The eighteenth exercise of the laboratory manual titled Unknown Identification and Bergey’s Manual is an experiment to identify an unknown bacterium. In this exercise, a student must randomly choose a numbered bacterium available to the class. The keys in Appendix H, located on the last pages of the book, are the major helpful tools in this exercise because it provides completed steps of tests that needs to be performed in order to distinguish certain bacteria. This means that in this exercise, various types of tests and techniques must be performed to identify the chosen unknown bacterium. The unknown bacterium that I selected was number thirty-nine in which I discovered as the Bacillus megaterium after conducting several tests.
I was given unknown organism #14, in order to find out what organism I had, I had to perform several different biochemical tests to identify it. Starting with the Gram stain test, which is performed to differentiate Gram-positive and Gram-negative cells. After staining, when observed through the microscope Gram-positive cells are a purple color with thick peptidoglycan cell walls. Gram-negative cells are a pinkish/red color with thinner cell walls. (handout G. s.) My organism was observed to be pinkish rod shaped meaning it is Gram-negative bacteria.
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
During this investigation to identify the unknown bacterium, seven different biochemical tests were performed. All biochemical tests were performed according to the Eastfield Microbiology Lab Manual. As with...
Food borne illnesses are caused by consuming contaminated foods or beverages. There are many different disease-causing microbes, or pathogens. In addition, poisonous chemicals, or other harmful substances can cause food borne illnesses if they are present in food. More than two hundred and fifty different food borne illnesses have been described; almost all of these illnesses are infections. They are caused by a variety of bacteria, viruses, and parasites that can be food borne. (Center 1)
A SWOT analysis of the food control system in Bahrain revealed that certain strengths and weaknesses are inherent in the system. In addition to the weaknesses and the strengths, there are threats that would negatively affect the system if not prevented or brought under control. Nevertheless, the there are opportunities available for responding to the threats, making the Bahrain food control systems more efficient and effective. It is therefore important that some or all of these strengths, opportunities, threats, and weaknesses are reviewed. Conspicuous among the weaknesses is the fact that limited resources are available for the agencies and the personnel employed in the Bahrain food control system. Related to lack of resources is the lack of skills and competencies in applying modern techniques, more so in microbiological and chemical analysis. The second weakness of the Bahrain food control system is that most of the laws and regulations on food safety and control are not based on risk- or science-based analysis. In other words, the laws could be outdated and irrelevant in comparison with the latest mechanisms by which pathogens and other contaminants affect foodstuffs (Nestle, 2007). Furthermore, Bahrain lacks the technical expertise or competent enough personnel who could assess the effectiveness and the applicability of their food control laws.
Food is a product that is rich with nutrient and can be contaminated with exposed to major source such as water, air, dust, sewage, insects and rodent (Oi Nee and Norrakiah, 2011). As a food handler they need to handle the changes in preparation techniques and food production because the fact remains whereby food is the source for microorganism which can cause illness (Oi Nee and Norrakiah, 2011).