An unknown lab report in microbiology typically involves identifying an unknown bacterial strain through a series of tests and observations. This process can be organized into a flowchart to help students understand and follow the steps involved.
The first step in identifying an unknown bacterial strain is to obtain a pure culture of the bacteria. This can be done by streaking a sample onto a petri dish and allowing it to grow until individual colonies are visible. It is important to ensure that the culture is pure, as this will make it easier to accurately identify the bacteria later on.
Once the pure culture has been obtained, the next step is to perform a series of physical and chemical tests on the bacteria to gather information about its characteristics. These tests may include observing the shape and size of the bacteria, determining its optimal temperature and pH range, and testing for the presence of certain enzymes or metabolic pathways.
Based on the results of these tests, the bacteria can be narrowed down to a particular group or family. For example, if the bacteria are gram-negative and rod-shaped, it is likely that they belong to the family Enterobacteriaceae.
At this point, it may be necessary to perform additional tests to further narrow down the identification. For example, the bacteria may be tested for the presence of specific enzymes or metabolic pathways that are characteristic of certain species within the family.
Once all of the necessary tests have been completed, the results should be compiled and used to identify the unknown bacterial strain as accurately as possible. This may involve consulting reference materials or consulting with a microbiologist to confirm the identification.
Overall, the process of identifying an unknown bacterial strain in a microbiology lab report involves a series of tests and observations that are organized and analyzed in a logical manner. By following a flowchart and gathering as much information as possible about the bacteria's characteristics, it is possible to accurately identify the unknown strain and understand its behavior and potential implications.
(Sample) Unknown Lab Report
The endospore staining identified the presence of endospores in the bacteria. EMB Streak for isolation. This was necessary for our group because, rather than looking up the results through a source in retrospect, saving time , the strains our particular group have may be different than a text book definition. This was to allow the gram positive and gram negative to be spread out, creating separate colonies. This test for bacteria that produce thoisulfate reductase H2S shown by the appearance of black in the tube.
This test showed positive which gave me P. Lab Procedure We have included the basic procedure for doing many common biochemical tests below. Hemolysis - Blood Agar Intended Use Blood agar is used to support the growth of fastidious organisms and to determine the type of hemolysis destruction of red blood cell walls an organism produces. Workers of the FDA must be able to identify microbial contaminants that lead to food spoilage and make consumers sick. It is suggested that culture 11 is a sample of Enterobacter aerogenes. Acid-fast cells, due to the mycolic acid, bind with the primary stain much more easily and resist decolorization much more effectively.
The only one of three possibilities to contain endospores was B. It can also be found in beer and dairy products. This project provided the opportunity for us to use our knowledge of differential tests toward identifying unknown bacteria. Beta hemolysis is indicative of S. Figure 10- Single colony of Known unknown on NA plate At this point, I went in a different direction on the flow chart from the unknown Gram positive. The first step taken was to use an inoculating loop streak and dry heat on a nutrient agar plate to get the bacteria to grow. The differential tests Unknown Report On Microbiology And The Epidemiology Of An Organism Kelsey Nolte Microbiology Otero Junior College Mr.
This was done to ensure a pure and fresh sample of the unknown for the next week. This study was completed from the knowledge and methods we have obtained throughout the course and laboratory assignments of microorganism identification. Enterococcus mundtii mannitol pos. The purpose of these procedures is to discovery the identity of an unknown microbe by observing its reactions to a barrage of chemical and physical tests. Unlike with my unknown Gram positive, the results for this test came back with a very strong profile for E. A gram stain was taken from a sample of the bacteria growing on the nutrient agar. On day two, the plate was examined to show some green and white colonies of bacteria growth.
This experiment was done by applying methods in order to identify an unknown bacterium. Based on those results, I concluded that my Gram-positive isolate was catalase positive, and was therefore either Staphylococcus or Micrococcus. From the resulting heterogeneous The cell morphology, as can be seen in Figure 2, is clustered cocci. The MSA test which is primarily used on gram positive bacteria, provided a negative result for P. This means that peptone was deaminated, which left alkaline end products no gas end products.
Once the two bacteria were incubated, grown, and isolated they were each individually streaked on a Trypticase Soy Agar plate to isolate individual colonies to be studied, tested and identified. Being able to determine the identities of microorganisms is a very important task that can help people in many different settings. Coagulase Add a loop-full or 0. The outbreak can be traced back to a single meat packing plant in Illinois 6. After narrowing down my search to the oral cavity and GI tract sample plates, I needed to ensure that I had pure cultures of a Gram negative and a Gram positive. Group B Streptococcus agalactiae No Staphylococcus saprophyticus Optochin Sensitivity Yes Streptococcus pneumoniae 5 No Streptococcus mitis Identification flow charts Family Enterobacteriaceae Lactose Positive ID Flowchart Family Enterobacteriaceae Lactose Fermentation Citrobacter diversus Citrobacter freundii Enterobacter aerogenes Enterobacter cloacae Enterobacter amnigenus Enterobacter intermedius Erwinia carotovora Erwinia chrysanthemi Escherichia coli Klebsiella oxytoca Klebsiella pneumoniae See Lactose Negative Flowchart for Enterobacteriaceae subsp. Chose a well isolated colony.
Results Test Gram Stain Purpose To determine the Gram reaction of the organism and identify the morphology Oxidase Test To determine the presence of cytochrome c Methyl Red Test To determine if the organism ferments glucose through mixed acid fermentation VogesTo determine if Proskauer Test the organism performs 2,3butanediol fermentation MacConkey Test To determine if the organism ferments lactose into acid end products Reagents Crystal Violet, Iodine, Alcohol, Safranin Observations Pink Rods Oxidase Reagent No color change Methyl Red reagent No color change Reagent a and Ethanol Reagent b Potassium Hydroxide and Water Lactose, Bile Salts, Crystal Violet, Neutral Red No color change Pink growth on media Result Gram Negative, bacteria Oxidase test negative no cytochrome c Negative Methyl Red test no mixed acid fermentation Negative VogesProskauer test no acetoin production through 2,3butanediol fermentation Positive MacConkey Test Lactose fermentation Discussion After performing all of my test, the results from each test was gathered and interpreted. Unknown C was determined to be a Gram- negative rod. The problematic issues from 123 was that the Gram positive would not grow and with the due date fastly approaching, the instructor supplied tube alternate 8. The oral cavity is well suited for bacterial growth, as it provides host bacteria with a regular source of nutrients and water, all while maintaining a moderate temperature. Is bacterium can live in aerobic and anaerobic conditions. After the Gram reaction was determined on Bacteria 1 and Bacteria 2, different biochemical tests were done according to the dichotomous keys provided in the lab manual. Three new NA plates were from the original mixed cultures were done in the same fashion of pulling through all lines.
The Simmons citrate confirmed the indole results. The purpose of this study was to identify the unknown bacteria by applying all the methods that have been learned so far in the microbiology laboratory class. They can also grow well in a nitrogen environment and is halophilic. On 29 May 2017, the first procedure to be done was to streak the unknown out on a nutrient agar plate. My sample came back with a 99% match to S.
After incubating the TSA plate for 24-48 hours the bacterium grew and their characteristics were recorded. Also knowledge of different bacteria helped others make antibiotics used today. This bacterium can become resistant to many antibiotics such as methicillin, cephalosporins and erythromycin which make it much more difficult to treat. To verify my results of a Gram negative Bacillus rod, the steps were repeated in re-growing the bacteria. The Urea test was implemented to name the unknown.
When cooking meat, use a thermometer to make sure the recommended temperature has been reached to ensure bacteria no longer existed in the food 1. Avila, Maria et al. The purpose for this study is for the microorganism to be identified. See probable results table below. Place a novobiocin disk lightly onto the surface. They are easily killed by boiling the water they may be living in or using a basic sterilization process 4. The quadrant streak helped spread out the bacteria and made it easier for the two different bacteria to make colonies that could be differentiated by the naked eye.