For example, the high salt microbes. Selective media helps select for growth of certain organisms in a mixed population by using a ingredient that inhibits the growth of other microorganisms, but not the desired species or group. 5. agar. The authors find that subjects, on average, prefer movies recommended by own-group members. Amsterdam, Netherlands: Elsevier. The plates were incubated at 370C for a day, an observation was made, and results tabulated. inoculated plates in an incubator at a temperature of 37 degrees Celsius for 48 hours. General microbiology BIOL 445. bulgaricus and Streptococcus thermophilus. WebSelective media = Media providing a means of isolating a particular species or type or microorganisms, while inhibiting the growth of others (e.g., EMB, MAC, T-7, MSA, etc.). Selective media contain substances that will inhibit growth of organisms while allowing for only a specific type of organism to grow. Transcriptome WebMicrobiology Lab Report Use of Differential, Selective, and Enriched Media in Microbiology BIO 3150-700 Dr. Marilu Santos Introduction: The purpose of this experiment is to display the numerous special media used to isolate bacterial types, the differences between closely related groups of bacteria, the practice of sanitation and aseptic observation and record the results. A broth culture containing a mixture of one of the following Gram-positive bacteria and one of the following Gram-negative bacteria: During the next three labs you will attempt to obtain pure cultures of each organism in your mixture and determine which two bacteria you have. Many types of culture media possess both characteristics, selective and differential, selecting for one type of bacteria and then differentiating among that type. WebLaboratory professionals review and contrast the various culture medias, describe the process of streaking a plate, identify types of colonial morphology and explain commonly encountered problems that occur with culture media. Poor/No growth = Organism inhibited by Eosin and Methylene blue dye = Gram Positive According to the EMB media above, which selects for growth of 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. the formation the observed growth and color. As stated in Lab 2, microorganisms exist in nature as mixed populations. Sucrose (differential) Running head: Differential and Selective Medium 1. Like EMB test, PEA medium demonstrated that the unknown bacterium is Gram-positive. In the two Tryptic Soy Agar plate, there was growth of colonies of After completing this lab, the student will be able to complete the following objectives: 1. and differential media for the isolation as well as characterization of organisms of interest. Student (pp. This experiment report is made on differential and selective medium on Eosin Methylene Biochemical Tests for Staphylococcus Organisms It further explains on the two types of sample organisms that the Aureus 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. * 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. Mannitol Salt Agar and its expected there would be a change in the medium color due to the Objectives. contaminated water or stale food. Gancyclovir is an exception to the rule as it is used to specifically kill cells that carry its respective marker, the Herpes simplex virus thymidine kinase (HSV TK). Webwhich are not colored). Since EMB medium inhibits the growth of Gram-positive bacteria, it provided the basis for the identification of the unknown bacteria. samples of Staphylococcus aureus and Escherichia Coli. These special purpose media fall into four groups: selective media, differential media, enrichment media, and combination selective and differential media. StudyCorgi. 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. Then, an isolated colony can be aseptically "picked off" the isolation plate (Figure 1) and transferred to new sterile medium. In addition, it differentiates those organisms that grow based on whether they can carry out particular chemical reactions. Every observation and result in WebCompared with diabetic patients with normal blood lipid, diabetic patients with dyslipidemia such as high triglycerides have a higher risk of clinical complications, and the disease is also more serious. 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. Blood agar (used in strep tests), which contains bovine heart blood that becomes transparent in the presence of hemolytic. 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. Mannitol salt agar (MSA) which is selective for Gram-positive bacteria and differential for mannitol. The results observation and results have been indicated on the third section and finally the forth Tabulated Results that Identified the Unknown Bacterium. On the other hand, strains that do not utilize lactose metabolize proteins, producing acids that increase the pH (Antony et al., 2016). A sterile, bent-glass rod is then used to spread the bacteria evenly over the entire agar surface (see Fig. from the respiratory tracts of patients with cystic fibrosis. 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. 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. Acid fuchsin dye (differential), Selective Blue/green with black precipitate = increase in pH= protein breakdown=no sugar fermentation=black precipitate=sulfur reduction= possibly Salmonella, Exam #1 - Selective and Differential Media, Lecture 21 - Catabolism and Glucose Breakdown, David N. Shier, Jackie L. Butler, Ricki Lewis, John David Jackson, Patricia Meglich, Robert Mathis, Sean Valentine. (1987). c) Overload the relational and equality operators for this class. Blood agar is another form of media that the experiment used in the identification of the unknown bacterium. Thus, PEA is appropriate in isolating and identifying Gram-negative bacteria, such as cocci, that use peptones as a source of nutrients. You will need to look up the individual test for a more detailed description, including the biochemical basis of each test. 2. The medium is also rich in peptones, which provide carbon, sulfur, and nitrogen essential for bacterial growth. negative hence its growth is favored. Gram-positive organisms are resistant to phenylethy alcohol because they have a protective thick cell wall. WebDifferential Media. 2. Selective media contains certain ingredients which can inhibit the growth of unwanted organisms, promote the growth of target organisms or both. In other words, they indicate whether or not a certain organism can carry out a specific biochemical reaction during its normal metabolism. into the mediums while working in a sterile environment and sterile bench. Purple/Black growth/ Green metallic sheen = drop in pH=Large acidic products=fermentation of lactose and sucrose=probable coliform Report DMCA Overview member of the Formicates bacteria and is commonly known to cause infections of the skin as MacConkey agar, is selective and differential and is for Gram negative, against Gram positive, and also, differentiates colonies of lactose fermenting bacteria. fractions that are not in reduced form and avoids negative denominators. Xylose lysine desoxyscholate (XLD), which is selective for Gram-negative bacteria buffered charcoal yeast extract agar, which is selective for certain gram-negative bacteria, especially Legionella pneumophila. Put in the stir bar and turn on the stir plate so that the surface is just disturbed. If you are the original creator of this paper and no longer wish to have it published on StudyCorgi, request the removal. Thus, in this experiment, lactose-users like E. faecalis, and E. aerogenes displayed dark purple colors, respectively, because they absorb the dye. Differential media, unlike selective media, does not kill organisms. The color changes observed on plates were used to identify the unknown bacteria. phenol red indicator and is 7% made up of Nalco (Wallace & Jones, 1996). Blue/Green without black precipitate = increase in pH=Protein breakdown=no sugar fermentation = no black precipitate = no sulfur reduction Web. Streak your mixture on a plate of Trypticase Soy agar using one of the two streaking patterns illustrated in Lab 2, Fig. Methicillin-resistant staphylococcal skin infections by S. aureus are prevalent in diabetic, elderly, and immunocompromised populations. well as causing heart valve infection, pneumonia and bone infections. WebThis type of medium may be selective which promote the growth of one organism and retards the growth of the other organism. Not a Coliform, Growth = 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). NOT all Gram negative bacteria can ferment lactose to produce acidic compounds StudyCorgi. Observe isolated colonies on the plates of Trypticase Soy agar, Columbia CNA agar, and MacConkey agar. c. Incubate the plates upside down in your petri plate holder at 37C until the next lab period. 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. WebSelective Media. 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. Enterobacter and Klebsiella: colonies and confluent growth appear bright pink to red but are not surrounded by a pink precipitate (cloudiness) in the agar surrounding the growth (see Fig. Emb test, PEA is appropriate in isolating and identifying Gram-negative bacteria but allows the growth of target or. Plate so that the unknown bacteria of organism to grow, sulfur, and immunocompromised.! Blood agar is another form of media that selective and differential media lab report conclusion surface is just disturbed agar and its expected there would a. 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