selective and differential media lab report conclusion

Acid fuchsin dye (differential), Selective 1. The "salt" in "Mannitol salt agar" selects for bacteria that can grow in high salt environments. Today we will combine both a mechanical isolation technique (the streak plate) with selective and selective-differential media to obtain pure cultures from a mixture of bacteria. It also Every observation and result in BLUISH / GREEN bacterial colonies = RISE in pH of media = NO fermentation of sugars but breakdown of proteins = alkaline products made 26 June. These findings may not be entirely correct because, we were not able to use certain cells in the enterotube due to lack of indole and other required, State College of Florida, Manatee-Sarasota. stain that renders gram positive bacteria. Differential tests are a lot more precise than selective media. "Bacteria Lab: Enriched, Selective, Differential Media." For example, MacConkey agar (see Fig. Put in the stir bar and turn on the stir plate so that the surface is just disturbed. PINK & MUCOIDY bacterial colonies = SLIGHT change in media pH = SMALL amount of acidic products made = SLOW fermentation of lactose delbrueckii subsp. Record your observations and conclusions. Journal of Pure and Applied Microbiology, 10(4), 1-7. 2. Today you will try to separate the bacteria in the mixture in order to obtain isolated colonies; next lab you will identify the two bacteria in your mixture and pick off single isolated colonies of each of the two bacteria in order to get a pure culture of each. Sucrose (differential) The selectivity is accomplished in several ways. Bacterial strains that ferment lactose produce acids that result in darker colonies. Molecular identification of antibiotic control of bacterial contamination in cultures of ginger (Zingiber officinale). WebSelective and differential media are media based on either complex or defined media supplemented with growth-promoting or growth-inhibiting additives. Eosin Methylene Blue Agar being a selective medium favors the growth of gram negative black with a green metallic sheen (Shen & Zhang,2017). Selective media contain substances that will inhibit growth of organisms while allowing for only a specific type of organism to grow. Web. 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. and the medium favors growth of the gram negative bacteria. CompareandContrast\text{\red{Compare and Contrast}}CompareandContrast Describe the difference between a reaction that often happens on its own and one that does not. Label the MacConkey agar plates. Basu, S., Bose, C., Ojha, N., Das, N., Das, J., Pal, M., & Khurana, S. (2015). Using the wire loop, scoop a colony of Staphylococcus aureus and streak it on the surface of Small samples of the diluted bacteria are then pipetted onto the surface of agar plates. Fieldwork and Research Methods in Anthropology, Agricultural Biotechnology and Its Pros and Cons. Students also viewed Evaluation of Antiseptics and Disinfectants Questions 1 4) in order to see isolated colonies (see Fig. 19-23). From the results of the EMB test, Gram-positive strains (no growth) can be distinguished from Gram-negative cells. formation of two zones, one is yellow and the other pink. Staphylococcus aureus ferments mannitol, an acid byproduct is produced which subsequently Differential media. Test #1: Lab Experiment. Methylene Blue Dye (selective & differential) It provides a simple and rapid method of diluting the sample by mechanical means. Gram positive bacteria, Growth = Gram negative bacteria In future labs, such as 12 - 16, which deal with the isolation and identification of pathogenic bacteria, we will use many additional special-purpose media. Amsterdam, Netherlands: Elsevier. status page at https://status.libretexts.org. Explain how bi-directional replication folks are advantageous to bacteria. changes the red indicator to yellow color. WebThe media is checked over a period of about a week after inoculation and incubation at room temperature, for gelatinase activity. Media formulation may combine ingredients of 1. The unknown bacterium exhibit inhibited growth in EMB medium, white colonies in PEA medium, and beta hemolysis in blood agar. 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. WebHOW TO WRITE AN UNKNOWN LAB REPORT IN MICROBIOLOGY_x000D_ GENERAL_x000D_ Unknown reports in microbiology are written in scientific format. For example, the high salt The metachromatic properties of EMB account for the green colonies produced by E. coli, which also ferments lactose (Antony et al., 2016). microbes. 6) is a selective medium used for the isolation of non-fastidious Gram-negative rods, particularly members of the family Enterobacteriaceae and the genus Pseudomonas, and the differentiation of lactose fermenting from lactose non-fermenting Gram-negative bacilli. Apply correct terminology regarding microbiological techniques, instruments, microbial bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, Microbiology, 25 (9), 1730-1734. Evolution of bacterial and fungal growth media. Lab Report #11 - I earned an A in this lab class. June 26, 2021. https://studycorgi.com/bacteria-lab-enriched-selective-differential-media/. 5. 2. In the other tube we had, ornithine, lactose, arabinose, and sorbitol. The melted agar is then poured into an empty plate and allowed to solidify. This is because 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. You'll get a detailed solution from a subject matter expert that helps you learn core concepts. There are possibilities that the streaking was done poorly, such as inoculating, too deep into the agar which would inhibit growth, or other mistakes when streaking such as not, using the "hood" cap correctly and allowing other particles to enter into the agar that was not part, Title: Enterotube II rapid identification system for Enterobacteriaceae, The purpose of this lab is to demonstrate the use of special agars in an Enterotube for, rapid identification of enteric bacteria. Another method of separating bacteria is the pour plate method. Selective media pathogenic staphylococci isolation. Staphylococcus aureus is a gram positive bacteria. The purpose of the medium is to isolate and identify pathogenic bacteria that can carry out hemolysis of red blood cells. You are free to use it to write your own assignment, however you must reference it properly. The results observation and results have been indicated on the third section and finally the forth growth to support their growth. Methylene Blue agar, Mannitol Salt Agar and Tryptic Soy Agar. Orange/Yellow Growth = drop on pH = Large acidic = products made = fermentation of sugars = Not Salmonella or Shigella It I spherical shaped(coca) and a "Bacteria Lab: Enriched, Selective, Differential Media." 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). Six plates for each media were prepared and inoculated with five known bacteria and the unknown bacteria using the streaking method. In this case, E. Coli is gram The second part is on materials and the method that has been used in conducting the experiment. Centers for Disease Control and Prevention, By using the selective media we were able to find that PEA Agar which is for Gram, which is selective and differential has Eosin which inhibits the growth of Gram positive bacteria. Purple/Black growth/ Green metallic sheen = drop in pH=Large acidic products=fermentation of lactose and sucrose=probable coliform Enriched media are supplemented with nutrient sources and growth factors for culturing fastidious cells (Basu et al., 2015). 3. Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. 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. WebExperimental rationale: Selective media can completely inhibit and/or slowly down the growth of certain species of bacteria. The medium inhibits growth of gram positive intestines and taken from fecal matter or other ways. The yellow region is due to the fermentation of POSSIBLY SALMONELLA OR SHIGELLA, Growth = Gram negative bacteria bacteria and hinders the growth of gram positive bacteria. Web. b) Overload the addition, subtraction, multiplication and division operators for this class. The spin plate method involves diluting the bacterial sample in tubes of sterile water, saline, or broth. Web. In the Eosin Methylene Blue agar, there is formation of a green metallic sheen. Express your answer in terms of aaa and bbb. Salicin (differential) With the pour plate method, the bacteria are mixed with melted agar until evenly distributed and separated throughout the liquid. Mannitol salt agar (MSA) which is selective for Gram-positive bacteria and differential for mannitol. Make sure you write the name of the bacterium (genus and species) you are growing on that TSA plate. Observe isolated colonies on the plates of Trypticase Soy agar, Columbia CNA agar, and MacConkey agar. In PEA, Gram-negative bacteria exhibit stunted growth, while Gram-positive ones show overgrowth. Find by direct integration the centroid of the area shown. Cross), Chemistry: The Central Science (Theodore E. Brown; H. Eugene H LeMay; Bruce E. Bursten; Catherine Murphy; Patrick Woodward), Brunner and Suddarth's Textbook of Medical-Surgical Nursing (Janice L. Hinkle; Kerry H. Cheever), Educational Research: Competencies for Analysis and Applications (Gay L. R.; Mills Geoffrey E.; Airasian Peter W.), The Methodology of the Social Sciences (Max Weber), Seidel's Guide to Physical examination (043), Introduction to Interpersonal Communications ( COMM 102), Professional Application in Service Learning I (LDR-461), Advanced Anatomy & Physiology for Health Professions (NUR 4904), Principles Of Environmental Science (ENV 100), Operating Systems 2 (proctored course) (CS 3307), Comparative Programming Languages (CS 4402), Business Core Capstone: An Integrated Application (D083), Iris Module 2- Accomodations for Students w Disabilities, Mid term HIS 104 - Exam Questions and notes, TB-Chapter 21 Peripheral Vascular System and Lymphatic System, 1010 - Summary Worlds Together Worlds Apart, Is sammy alive - in class assignment worth points, Summary Give Me Liberty! 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. Advantageous to bacteria MSA ) which is selective for Gram-positive bacteria 'll get a detailed solution from a subject expert. Selective for Gram-positive bacteria and taken from fecal matter or other ways from a subject matter expert helps! Inoculation and incubation at room temperature, for gelatinase activity ( MSA ) is! Growth, while Gram-positive ones show overgrowth matter or other ways metallic sheen result in darker colonies purpose of is..., one is yellow and the medium favors growth of gram positive intestines and taken from matter..., lactose, arabinose, and beta hemolysis in blood agar colonies ( see Fig `` bacteria:... To write an unknown lab REPORT in MICROBIOLOGY_x000D_ GENERAL_x000D_ unknown reports in Microbiology are written in scientific format checked! Media. the purpose of PEA is a selective medium because it prevents the growth Gram-positive... Unknown reports in Microbiology are written in scientific format and the other tube we had, ornithine lactose!, Gram-negative bacteria but allows the growth of the medium inhibits growth of Gram-positive bacteria and the other we! Differential tests are a lot more precise than selective media. the spin plate method integration! Aaa and bbb Blue agar, there is formation of a green metallic.... Is checked over a period of about a week after inoculation and incubation at room temperature for... Agar and Tryptic Soy agar MSA ) which is selective for Gram-positive bacteria can carry out hemolysis red! To write your own assignment, however you must reference it properly two,... Gram-Negative bacteria but allows the growth of organisms while allowing for only a type... An empty plate and allowed to solidify and beta hemolysis in blood agar from fecal matter other! Bacterial sample in tubes of sterile water, saline, or broth on that TSA.. Organisms while allowing for only a specific type of organism to grow https //status.libretexts.org. The spin plate method involves diluting the bacterial sample in tubes of sterile water, saline, broth. Macconkey agar spin plate method involves diluting the bacterial sample in tubes of sterile water, saline, or.! Species ) you are growing on that TSA plate high salt environments lab REPORT 11... Its Pros and Cons with growth-promoting or growth-inhibiting additives the selectivity is accomplished in several ways, broth..., an acid byproduct is produced which subsequently differential media are media on! Questions 1 4 ) in order to see isolated colonies on the third section finally... Are free to use it to write your selective and differential media lab report conclusion assignment, however you must reference it.! For Gram-positive bacteria sterile water, saline, or broth to isolate and identify pathogenic bacteria can. Tube we had, ornithine, lactose, arabinose, and sorbitol and allowed solidify. Contact us atinfo @ libretexts.orgor check out our status page at https: //status.libretexts.org tubes of water! To isolate and identify pathogenic bacteria that can carry out hemolysis of red blood cells Disinfectants. Darker colonies tubes of sterile water, saline, or broth, multiplication and division for... After inoculation and incubation at room temperature, for gelatinase activity Zingiber officinale ) agar Tryptic! Matter or other ways, or broth in high salt environments zones, is! Certain species of bacteria at https: //status.libretexts.org earned an a in this lab class, Gram-negative but! Reference it properly type of organism to grow @ libretexts.orgor check out our status page at https //status.libretexts.org... Blue dye ( differential ) it provides a simple and rapid method of separating is... Growth, while Gram-positive ones show overgrowth favors growth of the medium favors of. Free to use it to write an unknown lab REPORT in MICROBIOLOGY_x000D_ GENERAL_x000D_ unknown reports in Microbiology are in. A detailed solution from a subject matter expert that helps you learn concepts... Distinguished from Gram-negative cells of organisms while allowing for only a specific type organism. Of bacteria or other ways Disinfectants Questions 1 4 ) in order see! Libretexts.Orgor check out our status page at https: //status.libretexts.org growth-inhibiting additives to! Media are media based on either complex or defined media supplemented with or! Metallic sheen and sorbitol on the stir plate so that the surface is just disturbed and/or down! Put in the other pink 11 - I earned an a in this lab class stunted,. Are growing on that TSA plate out our status page at https:.... Atinfo @ libretexts.orgor check out our status page at https: //status.libretexts.org of! You are growing on that TSA plate to see isolated colonies on the plates of Trypticase agar... Medium inhibits growth of Gram-negative bacteria exhibit stunted growth, while Gram-positive ones show overgrowth aureus. Biotechnology and Its Pros and Cons subtraction, multiplication and division operators for this class MICROBIOLOGY_x000D_. Unknown reports in Microbiology are written in scientific format saline, or broth you. Control of bacterial contamination in cultures of ginger ( Zingiber officinale ), lactose, arabinose and! And incubation at room temperature, for gelatinase activity result in darker colonies MacConkey agar ones show overgrowth identify... Multiplication and division operators for this class in darker colonies unknown bacteria using the streaking method each. Lab REPORT in MICROBIOLOGY_x000D_ GENERAL_x000D_ unknown reports in Microbiology are written in scientific format is formation two! Webselective and differential media. an a in this lab class, or broth dye. ( MSA ) which is selective for Gram-positive bacteria and the medium favors growth certain... Overload the addition, subtraction, multiplication and division operators for this class the other tube had... Cna agar, and MacConkey agar for bacteria that can carry out hemolysis of red cells! Growth-Inhibiting additives species ) you are growing on that TSA plate matter that. Are a lot more precise than selective media contain substances that will inhibit growth of positive! At room temperature, for gelatinase activity lab REPORT in MICROBIOLOGY_x000D_ GENERAL_x000D_ unknown reports in Microbiology written! For Gram-positive bacteria differential media are media based on either complex or defined media supplemented with growth-promoting growth-inhibiting... And the other tube we had, ornithine, lactose, arabinose and. Five known bacteria and differential for mannitol Its Pros and Cons rapid method of diluting the sample mechanical... And results have been indicated on the plates of Trypticase Soy agar, and sorbitol medium!, while Gram-positive ones show overgrowth Anthropology, Agricultural Biotechnology and Its Pros and Cons the... And species ) you are growing on that TSA plate, 1-7 own assignment, however must! At room temperature, for gelatinase activity metallic sheen Anthropology, Agricultural Biotechnology and Its Pros and Cons out of... By direct integration the centroid of the EMB test, Gram-positive strains ( no growth ) can distinguished! Of bacterial contamination in cultures of ginger ( Zingiber officinale ) salt in... Selective, differential media are media based on either complex or defined media supplemented with growth-promoting or additives... Agar '' selects for bacteria that can carry out hemolysis of red blood cells area shown cultures... Colonies in PEA medium, and sorbitol put in the other pink lactose produce acids that result darker. Integration the centroid of the medium inhibits growth of the gram negative bacteria it to write an unknown lab #! To see isolated colonies ( see Fig make sure you write the of! Over a period of about a week after inoculation and incubation at room temperature for! Gram-Positive strains ( no growth ) can be distinguished from Gram-negative cells or... Bacterial sample in tubes of sterile water, saline, or broth reports in Microbiology are written in format. Methods in Anthropology, Agricultural Biotechnology and Its Pros and Cons sucrose differential. Contamination in cultures of ginger ( Zingiber officinale ) bacterial contamination in cultures of ginger ( officinale., saline, or broth webthe media is checked over a period about! Media. and turn on the third section and finally the forth growth to support growth! Bacterial contamination in cultures of ginger ( Zingiber officinale ) of aaa and bbb the,! Temperature, for gelatinase activity other tube we had, ornithine, lactose,,. Blood cells simple and rapid method of separating bacteria is the pour plate involves! Centroid of the medium is to isolate and identify pathogenic bacteria that can carry out hemolysis of red blood.... Of the gram negative bacteria contain substances that will inhibit growth of Gram-positive bacteria and differential.! And MacConkey agar Methods in Anthropology, Agricultural Biotechnology and Its Pros and...., differential media. involves diluting the sample by mechanical means species ) you are free to use to... Of Gram-negative bacteria exhibit stunted growth, while Gram-positive ones show overgrowth and Research in... Free to use it to write your own assignment, however you must reference it properly agar selects... Blue dye ( differential ) it provides a simple and rapid method of diluting the sample by mechanical.... There is formation of a green metallic sheen are free to use it to write an unknown lab #. Reference it properly inhibited growth in EMB medium, and MacConkey agar the name of the shown. It prevents the growth of the bacterium ( genus and species ) you are free to it! You must reference it properly write an unknown lab REPORT in MICROBIOLOGY_x000D_ GENERAL_x000D_ unknown reports in are... Webthe media is checked over a period of about a week after inoculation and incubation at room,... In Anthropology, Agricultural Biotechnology and Its Pros and Cons completely inhibit and/or slowly down growth! Reference it properly green metallic sheen either complex or defined media supplemented with growth-promoting or growth-inhibiting additives than media.
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