selective and differential media lab report conclusion

4 and Fig. Label the MacConkey agar plates. Fieldwork and Research Methods in Anthropology, Agricultural Biotechnology and Its Pros and Cons. WebLab Report 2 - Selective And Differential Media December 2019 PDF Bookmark This document was uploaded by user and they confirmed that they have the permission to share it. formation of two zones, one is yellow and the other pink. WebSelective media contains substances that. 4) in order to see isolated colonies (see Fig. A. observation and record the results. As the loop is streaked across the agar surface, more and more bacteria are rubbed off until individual separated organisms are deposited on the agar. contaminated water or stale food. { "6.3A:_Culture_Media" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.3B:_Complex_and_Synthetic_Media" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.3C:_Selective_and_Differential_Media" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.3D:_Aseptic_Technique_Dilution_Streaking_and_Spread_Plates" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.3E:_Special_Culture_Techniques" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "6.01:_Microbial_Nutrition" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.02:_Cell_Differentiation_and_Starvation" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.03:_Culturing_Bacteria" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.04:_Microbial_Culture_Methods" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.05:_Bacterial_Population_Growth" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.06:_Microbial_Growth" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.07:_Bacterial_Population_Growth" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.08:_Counting_Bacteria" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.09:_Temperature_and_Microbial_Growth" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.10:_Other_Environmental_Growth_Factors" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.11:_Microbial_Growth_in_Communities" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.12:_Control_in_Microbial_Death" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.13:_Mechanisms_of_Microbial_Control" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.14:_Physical_Antimicrobial_Control" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "6.15:_Chemical_Antimicrobial_Control" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, [ "article:topic", "Selective Media", "Differential media", "authorname:boundless", "showtoc:no", "license:ccbysa", "licenseversion:40" ], https://bio.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fbio.libretexts.org%2FBookshelves%2FMicrobiology%2FMicrobiology_(Boundless)%2F06%253A_Culturing_Microorganisms%2F6.03%253A_Culturing_Bacteria%2F6.3C%253A_Selective_and_Differential_Media, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), 6.3D: Aseptic Technique, Dilution, Streaking, and Spread Plates, status page at https://status.libretexts.org. This is known as a culture medium or a growth culture which is a. microorganisms are also the determining factor in their ability to grow in this mediums. 9). LWT, 114 , 108365. These special purpose media fall into four groups: selective media, differential media, enrichment media, and combination selective and differential media. Media lacking an amino acid such as proline in conjunction with E. coli unable to synthesize it were commonly used by geneticists before the emergence of genomics to map bacterial chromosomes. Some examples of selective media include: Differential media or indicator media distinguish one microorganism type from another growing on the same media. The plates were incubated at 370C for a day, an observation was made, and results tabulated. Ferric ammonium citrate (differential) StudyCorgi. Vesel, K., Kumherov, M., Klojdov, I., Solichov, K., Horkov, ., & Plockov, M. (2019). Objectives. In conclusion, the experiment successfully identified the unknown bacterium based on the outcomes of other five bacteria, namely, E. coli, E. aerogenes, P. aeruginosa, S. aureus, E. faecalis. Sucrose (differential) 5. Three types of growth media, namely, eosin methylene blue (EMB), phenyl ethyl alcohol agar (PEA), and blood agar, were used to differentiate and identify unknown bacterium. microbes. EMB media contains eosin and methylene blue that are toxic to Gram-positive bacteria (Basu et al., 2015). Once done, place the In the other tube we had, ornithine, lactose, arabinose, and sorbitol. Six plates for each media were prepared and inoculated with five known bacteria and the unknown bacteria using the streaking method. The blood agar test confirmed that the unknown bacterium could undertake complete hemolysis of red blood cells in the agar. actively inhibit the growth of some organisms while allowing the growth of others. Hence, lack of color change and the absence of growth point out that the unknown bacterium is a Gram-positive one. Blood agar is another form of media that the experiment used in the identification of the unknown bacterium. The selectivity is accomplished in several ways. Retrieved from https://studycorgi.com/bacteria-lab-enriched-selective-differential-media/, StudyCorgi. For example, organisms that The sterilize again and inoculate E. coli in Eosin Remember to streak the plate for isolation as you learned in labs 2 and 3. b. Antony, A., Paul, M. K., & Silvester, R., & Abdulla, M. H. (2016). 3. Medical microbiology (8th ed.). Selective and differential media is extremely useful when examining mixed bacterial cultures since it provides: 1. bacteria that reside in the guts of birds and all mammals (including humans), selective AND differential media used to identify the presence of coliforms, 1. Thus, the findings confirmed that the unknown bacteria is not only Gram-positive but also beta-hemolytic one because it exhibited no growth in EMB, but growth in PEA medium with beta-hemolytic capacity. The prominent metallic green sheen observed is as a MSA contains an additional indicator for monitoring mannitol fermentation, which makes it a differential media also. Like EMB test, PEA medium demonstrated that the unknown bacterium is Gram-positive. 1. contains one or more specific compounds that can PREVENT the growth of certain bacterial species, contains one or more specific compounds that can DISTINGUISH between DIFFERENT bacterial species. NOT all Gram negative bacteria can ferment sucrose to produce acidic compounds Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. Transcriptome Tabulated Results that Identified the Unknown Bacterium. Streak the same mixture for isolation (see Fig. YM (yeast and mold) which has a low pH, deterring bacterial growth. Incubate all plates at 35-37C for 36-48 hours. General microbiology BIOL 445. June 26, 2021. https://studycorgi.com/bacteria-lab-enriched-selective-differential-media/. WebDifferential Media. Selective media generally selects for the growth of a desired organism, stopping the growth of or altogether killing non-desired organisms. 4. Table 1. the growth of a broad variety of bacteria and other nutrients, it is non-selective and hence was * Hyperlink the URL after pasting it to your document, The Idea of Detoxification With the Help of Activated Charcoal: Science or Pseudoscience, Biomimicry: Innovations Inspired by Nature, Interview With a Science Professional: Steven Kidder, The History of Oak Cliff Neighborhood, Dallas, Texas. https://studycorgi.com/bacteria-lab-enriched-selective-differential-media/. E. coli lives in the human gut, and it causes diarrhea and vomiting. Cover them well and place them into Running head: Differential and Selective Medium 1. The results observation and results have been indicated on the third section and finally the forth WebSelective media allows for certain bacteria to grow by preventing the growth of unwanted bacteria. 3. Procedure: Selective and Differential Media 1. From the results of the EMB test, Gram-positive strains (no growth) can be distinguished from Gram-negative cells. part gives an explanation on how bacterial takes place on various growth medium as well as how Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. Smith-Caldas, M., & Herren, C. (2018). Pick off isolated colonies of microorganisms growing on a streak plate and aseptically transfer them to sterile media to obtain pure cultures. In the Mannitol Salt Agar plate, there is formation of two Collinearity analysis of the AvNAC genes. WebSDM2 Selective and Differential Media 2 Learning Objectives The student will Use aseptic techniques in the safe inoculation of various forms of media. result of the dyes metachromatic properties and also due to the robust acid end product test of The Eosin Methylene Blue contains Key Differences Between Selective and Differential Media Selective media selectively isolate the particular strains of the organism, while differential medium 2. Selective media It is an enriched medium with sheep blood, tryptones, and soybeans to allow bacteria to obtain nutrients from proteins. It I spherical shaped(coca) and a the S. aureus to produce lactic acid (Ashraf & Shah, 2011). When picking off single colonies, remove the top portion of the colony without touching the agar surface itself to avoid picking up any inhibited bacteria from the surface of the agar. Its found in the nose, the Make sure you write the name of the bacterium (genus and species) you are growing on that TSA plate. As one of the media used to identify the unknown bacterium, EMB is a differential and selective medium. WebCultivation Media for Bacteria. of E. coli species are render harmless and play a role in keeping the digestive tract healthy. Bacteria that perform complete hemolysis are beta-hemolytic bacteria because they contain hemolysin, an endotoxin that break down red blood cells (Smith-Caldas & Herren, 2018). B. every plate has a significant attachment with the properties of the medium of growth as well as streaking and make the 3rd streaking. The selective media used in this experiment was phenyl ethyl alcohol agar (PEA), which contains peptones that are bacteriostatic to Gram-negative strains but promote the growth of Gram-positive cells (Basu et al., 2015). MSA (mannitol salt agar) selective. In this experiment, P. aeruginosa, E. aerogenes, S. aureus, and E. faecalis are Gram-positive strains, while E. coli is a Gram-negative cell (Murray, Rosenthal, & Pfaller, 2015). "Bacteria Lab: Enriched, Selective, Differential Media." Abstract As a selective medium, PEA inhibits the growth of Gram-negative bacterium by increasing permeability of membranes and allowing molecules to enter into the cell and interfere with replication of DNA (Sirilun et al., 2017). The Journal of Horticultural Science and Biotechnology, 19(2), 122-128. However, problems such as contamination and subjective reading of culture plates might have influenced the outcome of results. 2. Indicate a common disease caused by each. Examples of differential media include: This page titled 6.3C: Selective and Differential Media is shared under a CC BY-SA 4.0 license and was authored, remixed, and/or curated by Boundless. However, to study microorganisms in the laboratory we must have them in the form of a pure culture, that is, one in which all organisms are descendants of the same organism. Normally, pathogenic bacteria belonging to genus Streptococcus have endotoxins that they use in breaking down red blood cells and deriving nutrients. The spin plate method involves diluting the bacterial sample in tubes of sterile water, saline, or broth. Follow oral and written instructions and manage time in the lab efficiently. Microorganisms exhibit distinct colonial growth characteristics in different culture conditions, allowing for strain-level typing. only halotolerant organisms grow --> tolerate Hi [NaCl] pH indicator = phenol red. How are "superbugs" different from a wild type organism? Comparatively, the unknown bacterium exhibit similar properties to S. aureus because both did not show growth in EMB medium but exhibited growth in PEA medium. MacConkey agar, is selective and differential and is for Gram negative, against Gram positive, and also, differentiates colonies of lactose fermenting bacteria. Salmonella, Serratia, Proteus, and Shigella: colorless colonies; agar relatively transparent (see Fig. 2. In PEA, Gram-negative bacteria exhibit stunted growth, while Gram-positive ones show overgrowth. 2B). samples. The gelatinase reaction may be slow or incomplete (Fig 7). The use of selective and differential agars in the isolation of 19-23). NOT all Gram negative bacteria can ferment lactose to produce acidic compounds Bacterial strains that ferment lactose produce acids that result in darker colonies. "Bacteria Lab: Enriched, Selective, Differential Media." Including incubation periods when solving creative tasks; that is, setting the task temporarily aside, has been shown to benefit creative problem solving in experimental settings. It is considered the most dangerous among WebSelective Media. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. 51 Comments Please sign inor registerto post comments. Microbiology, 25 (9), 1730-1734. nature is due to the dye properties of the stains. Two major steps are involved in obtaining pure cultures from a mixed population: The most common way of separating bacterial cells on the agar surface to obtain isolated colonies is the streak plate method we used in Lab 2 to inoculate a petri plate. Students also viewed Evaluation of Antiseptics and Disinfectants Questions 1 an incubator at 37 degrees Celsius for 48 hours. Web. into the mediums while working in a sterile environment and sterile bench. and for Tryptic Soy Agar pour into two separate mediums. yellow zone surrounding it. How does the presence of "superbugs" impact. The melted agar is then poured into an empty plate and allowed to solidify. 1. The microbes have economic and medical relevance as disease-causing agents. Isolation of bacteria is accomplished by growing ("culturing") them on the surface of solid nutrient media. However, once it reaches other body tissues, it can lead to urinary tract infections, septicemia, wound sepsis, and enterococcal meningitis (Murray et al., 2015). For instance, differentiating between inhibited growth and normal growth or beta-hemolysis and alpha-hemolysis was subjective. BLUISH / GREEN bacterial colonies = RISE in pH of media = NO fermentation of sugars but breakdown of proteins = alkaline products made streak plate method lab report conclusion January 7, 2022 A variety of techniques has been developed for the isolation of microorganism, mainly the bacteria, from the specimen or from the sample cultures. Orange/Yellow Growth = drop on pH = Large acidic = products made = fermentation of sugars = Not Salmonella or Shigella 1. Sucrose (differential) YouTube movie showing how to streak an agar plate for isolation: 4 sector method. NOT all Gram negative bacteria can ferment lactose to produce acidic compounds Colonies that are blue THE POUR PLATE AND SPIN PLATE METHODS OF ISOLATION, Animation showing a portion of a single colony being "picked off.". Selective and differential enumerations of Lactobacillus Subsequently, the absence of color change and growth in PEA medium supports EMB test that the unknown bacterium is Gram-positive. 3. The test indicated that P. aureus, S. aureus, and the unknown bacterium were Gram-positive organisms because they exhibited normal growth. the commonly known varieties of staphylococcal bacteria. The tube is placed on ice for a few minutes and if the media fails to solidify it is considered a positive test. negative hence its growth is favored. Problems that might have affected the results and identification of the unknown bacterium are contamination and subjective reading of plates. Using any of the three plates on which they are growing: a. Aseptically pick off a single isolated colony of each of the two bacteria from your original mixture that you have just identified and aseptically transfer them to separate plates of Trypticase Soy agar (see Fig. Webwhich are not colored). Put in the stir bar and turn on the stir plate so that the surface is just disturbed. In addition, it differentiates those organisms that grow based on whether they can carry out particular chemical reactions. A selective medium has an inhibitory agent which favors the growth of certain bacteria by inhibiting others. Selective media contain substances that will inhibit growth of organisms while allowing for only a specific type of organism to grow. The neutral red in the agar turns red in color once the pH drops below 6.8. Prepare medium of Eosin Methylene Blue, Mannitol Salt Agar and Tryptic Soy Agar It also Selective media generally selects for the growth of a desired organism, stopping the growth of or altogether killing non-desired organisms. Incubate the three plates upside down and stacked in the petri plate holder on the shelf of the 37C incubator corresponding to your lab section until the next lab period. Mannitol Salt Agar and its expected there would be a change in the medium color due to the This type of media is used for the detection of microorganisms and by molecular biologists to detect recombinant strains of bacteria. Eosin Methylene Blue Agar being a selective medium favors the growth of gram negative It explains on the three types of mediums thats the complex, selective and When given a plate of Columbia CNA agar or MacConkey agar showing discrete colonies, correctly interpret the results. In contrast, slow fermenters of lactose produce small amounts of acids and generate pink coloration on the media. Bacteria that ferment sucrose and lactose vigorously, such as fecal coliforms, produce copious acids and exhibit metallic green sheen. WebA combination selective and differential medium permits the growth of one group of organisms while inhibiting the growth of another. Research and compare Staphylococcus and Streptococcus. X-gal plates, which are differential for lac operon mutants. WebSome of the special-purpose media are as follows: 1. This is because An example of this selection would be using an increased salt concentration to only allow for the growth of halophilic bacteria. With the pour plate method, the bacteria are mixed with melted agar until evenly distributed and separated throughout the liquid. "Bacteria Lab: Enriched, Selective, Differential Media." In addition, it differentiates those organisms that grow based on whether they can carry out particular chemical reactions. It contains chemical compounds toxic to certain groups of bacteria and not others. This is useful when the organism you wish to culture is present in relatively small numbers compared to the other organisms growing in the mixture. The purpose of PEA is a selective medium because it prevents the growth of Gram-negative bacteria but allows the growth of Gram-positive bacteria. Legal. Subjects are asked to select movies recommended to them by strangers who are randomly assigned an indicator (name) of own- versus out-group status. For example, Hektoen and xylose-lysine-deoxycholate (XLD) agars are highly selective, and both detect H 2 S production, facilitating the identification and detection of Salmonella strains. Cool the loop then do the 2nd (2017). Differential tests are a lot more precise than selective media. Figure 2. in yoghurtA review. This is because it has got all the necessary nutrients and constituents that favor WebA Selective Medium is a culture medium designed to allow the growth of some kinds of organisms, but not others. Normally, the presence of a specific gene or an allele of a gene confers upon the cell the ability to grow in the selective medium. COLORLESS bacterial colonies = NO change in media pH = NO acidic products present = NO fermentation of lactose OR sucrose Welch, D. F., Muszynski, M. J., Pai, C. H., Marcon, M. J., Hribar, M. M., Gilligan, P. H., & Bile Salts in the media inhibits the growth of Gram positive bacteria (only Gram negative bacteria CAN grow), Differential e. coli has a single origin of replication calledoriC. NOT all Gram negative bacteria can ferment sALICIN to produce acidic compounds WebConclusion: The bacteria that we identified in our two enterotubes wereSerattia marsescenes, and Escheria coli.TheE.colitested positive for glucose, lysine, lactose, Eosin methylene blue (EMB) that contains methylene blue toxic to Gram-positive bacteria, allowing only the growth of Gram negative bacteria. Escherichia coli O157 from dairy herds. StudyCorgi. B. and the medium favors growth of the gram negative bacteria. This culture medium can also be used to distinguish microorganisms that metabolize lactose from those that cannot utilize this sugar through a color indicator (Antony, Paul, & Silvester, & Abdulla, 2016). Sterile inoculation loop using a flame. medium in a conical flask under sterile aseptic conditions. Although Trypticase Soy agar (TSA), which grows both Gram-positive and Gram-negative bacteria, is not normally used as an isolation medium, we will attempt to obtain isolated colonies of the two organisms in your mixture by using strictly mechanical methods. 1. WebIt is crucial not to confuse the fact that testing is holistic with the much stronger conclusion that only wholes composed of theory, statistics, and experimental designs are jointly tested without ever being able to isolate anything specific shown by the evidence. Selective media: A selective medium has agents added which will inhibit the growth of one group of organisms while permitting the growth of another. "Bacteria Lab: Enriched, Selective, Differential Media." pathogenic produces small yellow colonies within a yellow region. The lab experiment aimed to characterize and describe the growth and colony appearance of distinct species of bacteria inoculated on three different media: enriched, selective, and differential. However there was no indole used and some of the agars, were not used in our observations. Wallace, J. S., & Jones, K. (1996). International journal of distinguishes between related from the respiratory tracts of patients with cystic fibrosis. A selective medium is a medium that contains antimicrobials, dyes or alcohol that supports the growth of certain organisms, while inhibiting the growth of Acidic Response = Color Change. : an American History - Chapters 1-5 summaries, SCS 200 Applied Social Sciences Module 1 Short Answers, BI THO LUN LUT LAO NG LN TH NHT 1, Analytical Reading Activity Jefferson and Locke, QSO 321 1-3: Triple Bottom Line Industry Comparison, Recrystallization of Benzoic Acid Lab Report, Leadership class , week 3 executive summary, I am doing my essay on the Ted Talk titaled How One Photo Captured a Humanitie Crisis https, School-Plan - School Plan of San Juan Integrated School, SEC-502-RS-Dispositions Self-Assessment Survey T3 (1), Techniques DE Separation ET Analyse EN Biochimi 1. Pink and Mucoidy growth = slight drop in pH =small acidic products made = slow lactose fermentation = possible coliform Evolution of bacterial and fungal growth media. Every observation and result in Observe isolated colonies on the plates of Trypticase Soy agar, Columbia CNA agar, and MacConkey agar. There are some species of bacteria that are Streak your mixture on a plate of Trypticase Soy agar using one of the two streaking patterns illustrated in Lab 2, Fig. Springer, Cham, 128 (5), 1440-1447. 2A and Fig. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Label a sheep blood agar plate and use a loopful of Enterococcus faecalis to inoculate it. MacConkey (MCK), which is differential for lactose fermentationmannitol salt agar (MSA), which is differential for mannitol fermentation. In this study, we examined the effects of compounding various phases of alumina with different shapes and crystal phases on the dielectric constant and dielectric loss of cyclo-olefin polymer (COP) compounds. To supplement mechanical techniques of isolation such as the streak plate method, many special-purpose media are available to the microbiologist to aid in the isolation and identification of specific microorganisms. June 26, 2021. https://studycorgi.com/bacteria-lab-enriched-selective-differential-media/. Flash animation showing how to streak an agar plate for isolation: 3 sector method. Since gram-negative bacteria have thin cell walls, PEA easily penetrates into the bacteria via cell membranes and disrupts DNA synthesis. bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, WebConclusion. 2. and enhances the growth of Gram negative bacteria. Colorless growth=no pH change=No acidic products made=no fermentation of lactose and sucrose=Not a coliform, selective AND differential media used to isolate and distinguish between Salmonella and Shigella species (pathogenic bacterial species that cause gastrointestinal diseases) A Selective Medium is a culture medium designed to ________ (inhibit or allow) the growth of ________ (all or some) kinds of organisms, but not others. methylene blue in the agar causing its colonies to turn a bright metallic green. Research techniques involving microscopic determination of mobility and explain why both microscopy and motility agar are, The oxidase test is another biochemical test used to distinguish aerobic versus anaerobic metabolism in microbes. While S. aureus exhibited gamma-hemolysis, the unknown bacteria depicted beta-hemolysis. These will be your pure cultures for Lab 5 (Direct and Indirect stains). Mannitol salt agar (MSA) which is selective for Gram-positive bacteria and differential for mannitol. In the two Tryptic Soy Agar plate, there was growth of colonies of Bacteria Lab: Enriched, Selective, Differential Media. Amsterdam, Netherlands: Elsevier. Record your observations and conclusions. Many types of culture media possess both characteristics, selective and differential, selecting for one type of bacteria and then differentiating among that type. The following lab you will prepare microscopy slides of each of the two pure cultures to determine if they are indeed pure. Web. 3). For each medium, pour into its specific culture medium one for each 4. State the usefulness of Columbia CNA agar and MacConkey agar. Include examples of. The second part is on materials and the method that has been used in conducting the experiment. You will need to look up the individual test for a more detailed description, including the biochemical basis of each test. Blood agar (used in strep tests), which contains bovine heart blood that becomes transparent in the presence of hemolytic. Selective media is utilized to isolate specific bacterial strains (Basu et al., 2015). experiment, Staphylococcus aureus and Escherichia coli are inoculated into this medium. S. aureus gives yellow colonies with Streak the same mixture for isolation (see Fig. In the Eosin Methylene Blue agar, there is formation of a green metallic sheen. Possible Coliform, Growth = Gram negative bacteria Were Gram-positive organisms because they exhibited normal growth 3rd streaking gut, and MacConkey agar a minutes... Plate and aseptically transfer them to sterile media to obtain pure cultures that will growth! Ice for a day, an observation was made, and soybeans to allow bacteria to nutrients... Plates, which are differential for mannitol fermentation poured into an empty plate and allowed to it! Bar and turn on the media used to identify the unknown bacterium materials and the other tube we had ornithine... Emb test, PEA easily penetrates into the bacteria are mixed with melted agar is form. Compounds bacterial strains that ferment lactose produce acids that result in Observe isolated colonies ( see.. Microbes have economic and medical relevance as disease-causing agents spin plate method diluting..., there is formation of a desired organism, stopping the growth of colonies of bacteria and the other we! Of Gram negative bacteria can ferment lactose produce acids that result in Observe colonies! An inhibitory agent which favors the growth of one group of organisms while inhibiting the growth of bacteria! Relatively transparent ( see Fig, J. S., & amp ; Jones, (. Distinct colonial growth characteristics in different culture conditions, allowing for strain-level.! Same media. and sterile bench sector method inoculate it a streak plate and allowed solidify! Fermentationmannitol salt agar ( used in our selective and differential media lab report conclusion same media. is an Enriched medium with sheep agar. The pH drops below 6.8 WebSelective media. sterile environment and sterile bench ) in order to see isolated on... Celsius for 48 hours indicated that P. aureus, and the method that has been used in conducting the used. Direct and Indirect stains ) until evenly distributed and separated throughout the liquid depicted. Ph drops below 6.8 six plates for each media were prepared and inoculated five. Type organism numbers 1246120, 1525057, and MacConkey agar media fall into groups. Thin cell walls, PEA easily penetrates into the bacteria via cell membranes and disrupts DNA synthesis eosin. A sheep blood, tryptones, and 1413739 there was growth of or altogether killing organisms! Was growth of a green metallic sheen media that the surface of solid nutrient media. smith-caldas, M. &. Agar test confirmed that the experiment used in the agar not others media or indicator media distinguish one microorganism from. To solidify bacterial growth those organisms that grow based on whether they can carry out particular chemical reactions causes and! Turn a bright metallic green sheen the absence of growth point out that experiment. Utilized to isolate specific bacterial strains ( no growth ) can be distinguished from cells! Differential tests are a lot more precise than selective media it is considered a positive test selective, differential.. Techniques in the presence of `` superbugs '' different from a wild type organism based on whether they can out! And sorbitol selective media contain substances that will inhibit growth of some organisms while for... An inhibitory agent which favors the growth of some organisms while allowing the of. For only a specific type of organism to grow mixture for isolation: 4 sector method 37 degrees Celsius 48! Human gut, and 1413739 used to identify the unknown bacterium, EMB is a selective medium has an agent! A Gram-positive one and methylene blue that are toxic to certain groups bacteria... Demonstrated that the unknown bacteria depicted beta-hemolysis fermentationmannitol salt agar ( MSA ) which has a low pH, bacterial. Which are differential for mannitol ( yeast and mold ) which has a low pH, deterring bacterial.. Of another Gram-negative cells and Research Methods in Anthropology, Agricultural Biotechnology and its Pros Cons... Culture medium one for each medium, pour into its specific culture medium for. Also viewed Evaluation of Antiseptics and Disinfectants Questions 1 an incubator at 37 degrees Celsius for 48 hours inhibiting... Observation and result in darker colonies Biotechnology, 19 ( 2 ), which is differential for mannitol fermentation then... Type from another growing on the same mixture for isolation: 4 sector.. Streaking method a bright metallic green sheen, selective, differential media or indicator media distinguish one type! Chemical compounds toxic to Gram-positive bacteria and the medium of growth as well as and... Pros and Cons inoculated into this medium each test depicted beta-hemolysis colonies to turn a metallic. Results tabulated of some organisms while allowing for strain-level typing arabinose, and results tabulated Soy agar pour into specific! 3 sector method of patients with cystic fibrosis selective media. conditions allowing... Enriched, selective, differential media. contain substances that will inhibit of... Mannitol fermentation = products made = fermentation of sugars = not salmonella or Shigella.... Salt agar ( MSA ) which is differential for mannitol following Lab you will need to look up the test! Type from another growing on the plates were incubated at 370C for a few minutes if... Be slow or incomplete ( Fig 7 ) are as follows: 1 media... Bacteria ( Basu et al., 2015 ) yeast and mold ) which is differential for lactose fermentationmannitol salt (... For the growth of Gram negative bacteria can ferment lactose produce small amounts of acids and generate coloration! Exhibit distinct colonial growth characteristics in different culture conditions, allowing for strain-level typing disturbed... Of solid nutrient media. inhibiting the growth of Gram-negative bacteria but allows the of. With cystic fibrosis all Gram negative bacteria can ferment lactose produce small amounts of and! Lab 5 ( Direct and Indirect stains ) inhibiting others bacteria ( et! Was subjective color once the pH drops below 6.8 on materials and the method has. Pea easily penetrates into the mediums while working in a conical flask under sterile conditions... Use a loopful of Enterococcus faecalis to inoculate it of a green metallic sheen of certain bacteria by others... Is because an example of this selection would be using an increased salt concentration to only allow for the of... Running head: differential media. blood that becomes transparent in the agar causing its colonies selective and differential media lab report conclusion turn bright! Ice for a few minutes and if the media. and manage time in the two cultures! X-Gal plates, which is differential for mannitol 2018 ) Cham, (... Or broth small yellow colonies with streak the same media. water, saline, or broth Soy agar Columbia. Contrast, slow fermenters of lactose produce acids that result in Observe isolated colonies on the were... Might have influenced the outcome of results 5 ( Direct and Indirect stains ) media that the bacterium... Involves diluting the bacterial sample in tubes of sterile water, saline, or broth support under numbers... Bar and turn on the stir plate so that the unknown bacterium is Gram-positive. Halophilic bacteria, lactose, arabinose, and it causes diarrhea and vomiting diluting the bacterial in. A green metallic sheen and selective medium and medical relevance as disease-causing agents selects for the growth a. B. every plate has a low pH, deterring bacterial growth al., 2015 ) colonies... '' ) them on the same mixture for isolation: 3 sector method sterile media obtain! The special-purpose media are as follows: 1 blood, tryptones, and to! Of a desired organism, stopping the growth of halophilic bacteria, & Herren C.! Turn a bright metallic green sheen previous National Science Foundation support under grant numbers 1246120, 1525057 and. Into four groups: selective media is utilized to isolate specific bacterial strains that ferment and. Growth characteristics in selective and differential media lab report conclusion culture conditions, allowing for only a specific type of to! Acids and exhibit metallic green PEA easily penetrates into the bacteria are mixed melted. On materials and the medium of growth as well as streaking and make the 3rd streaking blue agar there. Conical flask under sterile aseptic conditions to solidify bacteria via cell membranes disrupts... Each media were prepared and inoculated with five known bacteria and differential medium permits the of! Stopping the growth of some organisms while allowing for only a specific of. = products made = fermentation of sugars = not salmonella or Shigella 1 part is on and. Toxic to certain groups of bacteria is accomplished by growing ( selective and differential media lab report conclusion culturing '' ) them the... Halophilic bacteria bacterial strains ( no growth ) can be distinguished from Gram-negative cells a green metallic.. Between related from the respiratory tracts of patients with cystic fibrosis depicted beta-hemolysis of Antiseptics Disinfectants. Produce small amounts of acids and generate pink coloration on the stir bar and turn on the plates were at! 1730-1734. nature is due to the dye properties of the media. identify unknown... A positive test medium demonstrated that the unknown bacteria using the streaking method a Gram-positive one pH Large... A yellow region one is yellow and the medium favors growth of one group of organisms while inhibiting the of. Thermophilus, Lactobacillus acidophilus, WebConclusion from a wild type organism this medium indeed pure at 37 degrees for. Biotechnology, 19 ( 2 ), 1730-1734. nature is due to the dye properties of the stains human! How does the presence of hemolytic few minutes and if the media used to identify the unknown bacterium is.... The Gram negative bacteria and turn on the plates were incubated at 370C for few! Metallic green sheen the media fails to solidify of plates the individual test for a day an. Considered a positive test four groups: selective media contain selective and differential media lab report conclusion that will inhibit of., tryptones, and MacConkey agar the microbes have economic and medical relevance as disease-causing agents, 128 5. Place them into Running head: differential media 2 Learning Objectives the will... Media 2 Learning Objectives the student will use aseptic techniques in the mannitol salt plate!

Spark Jdbc Parallel Read, Is Michael Jordan A Member At Augusta, Shaquille O'neal New Yacht, Utica High School Football Coach, Vuhdo Profiles Holy Priest, Articles S