Remember to streak the plate for isolation as you learned in labs 2 and 3. b. Web(N.B. 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 Bacterial growth need a medium of the formation the observed growth and color. A selective medium is a medium that contains antimicrobials, dyes or alcohol that supports the growth of certain organisms, while inhibiting the growth of You'll get a detailed solution from a subject matter expert that helps you learn core concepts. Eosin Methylene Blue Agar being a selective medium favors the growth of gram negative * 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/. Lactobacillus delbrueckii subsp. inoculated plates in an incubator at a temperature of 37 degrees Celsius for 48 hours. There are hundreds of selective and differential media, but a few of the more common ones as well as those used for general purposes are described below: Differential media is used to differentiate bacteria with morphological and biochemical similarities. The unknown bacterium exhibit inhibited growth in EMB medium, white colonies in PEA medium, and beta hemolysis in blood agar. phenol red indicator and is 7% made up of Nalco (Wallace & Jones, 1996). various bacterial strains and microorganisms respond to growth in mediums with varying Sodium thiosulfate (sulfur source) contaminated water or stale food. Bacteria that cannot ferment sucrose or lactose tend to show white colonies, for they do not cause any changes in the media. Research and compare Staphylococcus and Streptococcus. Bacteria that cannot metabolize the peptone proteins cannot grow. The microbes have economic and medical relevance as disease-causing agents. For example, if a microorganism is resistant to a certain antibiotic, such as ampicillin or tetracycline, then that antibiotic can be added to the medium in order to prevent other cells, which do not possess the resistance, from growing. Cover them well and place them into CompareandContrast\text{\red{Compare and Contrast}}CompareandContrast Describe the difference between a reaction that often happens on its own and one that does not. Science - Volume 379 Issue 6628, 13 January 2023 - Free download as PDF File (.pdf), Text File (.txt) or read online for free. actively inhibit the growth of some organisms while allowing the growth of others. It further explains on the two types of sample organisms that the Aureus StudyCorgi, 26 June 2021, studycorgi.com/bacteria-lab-enriched-selective-differential-media/. PINK & MUCOIDY bacterial colonies = SLIGHT change in media pH = SMALL amount of acidic products made = SLOW fermentation of lactose The authors find that subjects, on average, prefer movies recommended by own-group members. If you use an assignment from StudyCorgi website, it should be referenced accordingly. After incubation, the area at the beginning of the streak pattern will show confluent growth while the area near the end of the pattern should show discrete colonies (see Fig. In Food Microbiology Laboratory for the Food Science Legal. https://studycorgi.com/bacteria-lab-enriched-selective-differential-media Blue/Green without black precipitate = increase in pH=Protein breakdown=no sugar fermentation = no black precipitate = no sulfur reduction (1315) Therefore, boronic acid networks often exhibit self-healing properties, (1618) are injectable, (19,20) and have stimuli-responsive behavior. Salicin (differential) fermentation. Wallace, J. S., & Jones, K. (1996). Like EMB test, PEA medium demonstrated that the unknown bacterium is Gram-positive. "Bacteria Lab: Enriched, Selective, Differential Media." Methylene Blue Agar plate and the other plate of Tryptic Soy Agar plate. Thad StudyCorgi. Indicate a common disease caused by each. WebCultivation Media for Bacteria. However there was no indole used and some of the agars, were not used in our observations. 1. LWT, 114 , 108365. Differential media, unlike selective media, does not kill organisms. A. Depending on the extent of breakdown, bacteria can give beta, alpha, and gamma outcomes, which show complete, partial, and absent hemolysis. Orange/Yellow Growth = drop on pH = Large acidic = products made = fermentation of sugars = Not Salmonella or Shigella Figure 1: General procedure to make media. Amsterdam, Netherlands: Elsevier. The purpose of the medium is to isolate and identify pathogenic bacteria that can carry out hemolysis of red blood cells. References Find by direct integration the centroid of the area shown. Six plates for each media were prepared and inoculated with five known bacteria and the unknown bacteria using the streaking method. The introduction WebSelective and differential media are media based on either complex or defined media supplemented with growth-promoting or growth-inhibiting additives. 4 and Fig. COLORLESS bacterial colonies = NO change in media pH = NO acidic products present = NO fermentation of lactose OR sucrose It also Selective media contains certain ingredients which can inhibit the growth of unwanted organisms, promote the growth of target organisms or both. The Eosin Methylene Blue contains POSSIBLY SALMONELLA OR SHIGELLA, Growth = Gram negative bacteria Blue Agar and Mannitol Salt Agar and Tryptic Soy Agar used for the control. Normally, pathogenic bacteria belonging to genus Streptococcus have endotoxins that they use in breaking down red blood cells and deriving nutrients. The Journal of Horticultural Science and Biotechnology, 19(2), 122-128. WebThe media is checked over a period of about a week after inoculation and incubation at room temperature, for gelatinase activity. Ashraf, R., & Shah, N. P. (2011). Legal. Figure 2. high [NaCl] of 7.5%. The results observation and results have been indicated on the third section and finally the forth 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) For instance, differentiating between inhibited growth and normal growth or beta-hemolysis and alpha-hemolysis was subjective. These special purpose media fall into four groups: selective media, differential media, enrichment media, and combination selective and differential media. the growth of a broad variety of bacteria and other nutrients, it is non-selective and hence was The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. Streak your mixture on a plate of Trypticase Soy agar using one of the two streaking patterns illustrated in Lab 2, Fig. Student (pp. 2A and Fig. Colonies that are blue and for Tryptic Soy Agar pour into two separate mediums. As the pH drops, the neutral red is absorbed by the bacteria, causing the colonies to appear bright pink to red. 5. While S. aureus exhibited gamma-hemolysis, the unknown bacteria depicted beta-hemolysis. In PEA, Gram-negative bacteria exhibit stunted growth, while Gram-positive ones show overgrowth. 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. the properties of the two microbes used in the experiment. Biochemical Tests for Staphylococcus Organisms (2017). The selectivity is accomplished in several ways. a) Create a constructor that prevents a 0 denominator in a fraction, reduces or simplifies 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. The aim of this experiment is to illustrate the uses of selective 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. Mannitol salt agar (MSA) which is selective for Gram-positive bacteria and differential for mannitol. NOT all Gram negative bacteria can ferment lactose to produce acidic compounds intestines and taken from fecal matter or other ways. conducive for their growth. WebSDM2 Selective and Differential Media 2 Learning Objectives The student will Use aseptic techniques in the safe inoculation of various forms of media. 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. 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. B. 4. 1. contains one or more specific compounds that can PREVENT the growth of certain bacterial species. Selective and differential medium for recovery of Pseudomonas cepacia BLUISH / GREEN colony color = RISE in pH of media = NO fermentation of sugars but breakdown of proteins = alkaline products made NOT all Gram negative bacteria can reduce sulfur, Growth = Gram negative bacteria These will be your pure cultures for Lab 5 (Direct and Indirect stains). However, its difference occurs in the degree of hemolysis as S. aureus exhibited gamma-hemolysis, while the unknown bacterium depicted beta-hemolysis. Salmonella & Shigella CANNOT breakdown lactose, sucrose or salicin sugars It was confirmed that the smaller the particle size, the higher the effect on the dielectric loss. Label the MacConkey agar plates. Sterile inoculation loop using a flame. Collinearity analysis of the AvNAC genes. 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. Microbiology, 25 (9), 1730-1734. Dr. Gary Kaiser (COMMUNITY COLLEGE OF BALTIMORE COUNTY, CATONSVILLE CAMPUS). Since EMB medium inhibits the growth of Gram-positive bacteria, it provided the basis for the identification of the unknown 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). 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. First, the mixture must be diluted until the various individual microorganisms become separated far enough apart on an agar surface that after incubation they form visible colonies isolated from the colonies of other microorganisms. WebDifferential/selective media contain chemicals whose reactions with the metabolites of the microbes result in a change in appearance of the media or the colonies themselves, thus NOT all Gram negative bacteria can ferment sALICIN to produce acidic compounds skin, groin, armpit and other areas. black with a green metallic sheen (Shen & Zhang,2017). Our provided with Many such media will be used in future labs to aid in the identification of microorganisms. and the medium favors growth of the gram negative bacteria. Medical microbiology (8th ed.). 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. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Flash animation showing how to streak an agar plate for isolation: 3 sector method. Using a differential test helps identify an unknown organism because they are either positive or negative for the specific test. Selective media: A selective medium has agents added which will inhibit the growth of one group of organisms while permitting the growth of another. samples of Staphylococcus aureus and Escherichia Coli. The products of chemical reactions after incubation give characteristic colony morphologies (Basu et al., 2015). Bacteria that ferment sucrose and lactose vigorously, such as fecal coliforms, produce copious acids and exhibit metallic green sheen. Since gram-negative bacteria have thin cell walls, PEA easily penetrates into the bacteria via cell membranes and disrupts DNA synthesis. "Bacteria Lab: Enriched, Selective, Differential Media." It is an enriched medium with sheep blood, tryptones, and soybeans to allow bacteria to obtain nutrients from proteins. 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. As one of the media used to identify the unknown bacterium, EMB is a differential and selective medium. Often, however, one bacterium overgrows another in a mixture and by the time you spread out the more abundantant organism enough to get isolated colonies, the one in smaller numbers is no longer on the loop so you may not see single colonies of each on the TSA next time. 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. and enhances the growth of Gram negative bacteria. e. coli has a single origin of replication calledoriC. In the other tube we had, ornithine, lactose, arabinose, and sorbitol. Escherichia coli O157 from dairy herds. The purpose of EMB as a selective medium is to allow the growth of Gram-negative bacteria but inhibits the growth of Gram-positive ones. 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.). Isolation of bacteria is accomplished by growing ("culturing") them on the surface of solid nutrient media. The "salt" in "Mannitol salt agar" selects for bacteria that can grow in high salt environments. Selective media medium in a conical flask under sterile aseptic conditions. For each medium, pour into its specific culture medium one for each This will guide your streaking. Some of these strains P. aeruginosa and E. aerogenes are opportunistic pathogens that cause pulmonary, gastrointestinal, and urinary tract infections as well as sepsis, particularly in hospitalized patients (Murray et al., 2015). pathogenic staphylococci isolation. Methylene Blue agar, Mannitol Salt Agar and Tryptic Soy Agar. E. faecalis is usually a nonpathogenic intestinal microorganism. Many types of culture media possess both characteristics, selective and differential, selecting for one type of bacteria and then differentiating among that type. B. The neutral red in the agar turns red in color once the pH drops below 6.8. There is also lactose fermentation that took place that Table 1. This paper was written and submitted to our database by a student to assist your with your own studies. Lab report Selective Differential mediums, Copyright 2023 StudeerSnel B.V., Keizersgracht 424, 1016 GC Amsterdam, KVK: 56829787, BTW: NL852321363B01, Principles of Environmental Science (William P. Cunningham; Mary Ann Cunningham), Civilization and its Discontents (Sigmund Freud), Campbell Biology (Jane B. Reece; Lisa A. Urry; Michael L. Cain; Steven A. Wasserman; Peter V. Minorsky), Give Me Liberty! Poor/No growth = Inhibited by Bile Salts = Gram Positive components. Subjects are asked to select movies recommended to them by strangers who are randomly assigned an indicator (name) of own- versus out-group status. X-gal plates, which are differential for lac operon mutants. Using the wire loop, scoop a colony of Staphylococcus aureus and streak it on the surface of Jain, Aravindaram, and Pal (2016) recognize contamination of cultures as a major challenge that microbiologists experience when culturing, isolating, and identifying unknown bacteria. 4 and Fig. 1. WebLab Procedure. Shen, C., & Zhang, Y. Lab Report #11 - I earned an A in this lab class. The chemistry behind this test is that PEA increases the permeability of membranes of Gram-negative bacteria and allows an influx of various molecules into the bacteria, resulting in the inhibition of DNA replication. formation of two zones, one is yellow and the other pink. Selective media generally selects for the growth of a desired organism, stopping the growth of or altogether killing non-desired organisms. Sirilun, S., Chaiyasut, C., Sivamaruthi1, B. S., Peerajan, S., Kumar, N., & Kesika, P. (2017). After incubation, discrete bacterial colonies can then be found growing both on the agar and in the agar. from the respiratory tracts of patients with cystic fibrosis. The chemistry behind this test is that Gram-negative bacteria ferment lactose and sucrose to produce acids, which react with eosin and methylene blue dyes to produce dark purple or metallic green colors. Web. bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, 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. EMB media contains eosin and methylene blue that are toxic to Gram-positive bacteria (Basu et al., 2015). Eosin Y and Methylene Blue dyes inhibit the growth of Gram positive bacteria (only Gram negative bacteria will grow well), Differential 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. 8). 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. 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. Research the oxidase test and describe how it is performed. 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. Pick off isolated colonies of microorganisms growing on a streak plate and aseptically transfer them to sterile media to obtain pure cultures. 19-23). Selective and differential enumerations of Lactobacillus Then make When given a plate of Columbia CNA agar or MacConkey agar showing discrete colonies, correctly interpret the results. For example, organisms that You will find more specific procedures for each biochemical test on the WebHOW TO WRITE AN UNKNOWN LAB REPORT IN MICROBIOLOGY_x000D_ GENERAL_x000D_ Unknown reports in microbiology are written in scientific format. changes the red indicator to yellow color. ORANGE / YELLOW bacterial colonies = DROP in pH of media = LARGE amounts of acidic products made = fermentation of the sugars in the media MSA (mannitol salt agar) selective. Ferric ammonium citrate (differential) Blood agar is another form of media that the experiment used in the identification of the unknown bacterium. Lactose (differential) 5) on a plate of MacConkey agar (selective for Gram-negative bacteria and differential for certain members of the bacterial family Enterobacteriaceae). However, problems such as contamination and subjective reading of culture plates might have influenced the outcome of results. 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. in yoghurtA review. Morphologically, enterococci and streptococci have spherical shapes. Growth = Not inhibited by Bile Salts - Gtam Negative Put in the stir bar and turn on the stir plate so that the surface is just disturbed. Small samples of the diluted bacteria are then pipetted onto the surface of agar plates. The acid being acidic in nature turens On the bottom of each of the three petri plate you are using today, divide the plate into thirds with your wax marker and label as shown below. On MANNITOL Salt Agar, Aureus which is 3). Bacteria Lab: Enriched, Selective, Differential Media. Therefore, the unknown bacterium was identified based on its ability to degrade red blood cells. The ability of the unknown bacterium to undertake complete lysis of red blood cells in the media depicts it as a beta-hemolytic bacterium. the commonly known varieties of staphylococcal bacteria. Enrichment media: An enrichment medium contains additives that enhance the growth of certain organisms. 4. 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. Defined media supplemented with growth-promoting or growth-inhibiting additives phenol red indicator and 7! Kill organisms or stale Food, pour into two separate mediums S., & amp ; Shah, P.. Microorganisms growing on a plate of Tryptic Soy agar pour into its specific culture medium for! Form of media that the unknown bacterium database by a student to your... # 11 - I earned an a in this Lab class about a after. Unknown bacterium depicted beta-hemolysis after inoculation and incubation at room temperature, for gelatinase.... Enrichment media: an enrichment medium contains additives that enhance the growth certain... Changes in the agar place that Table 1 the degree of hemolysis as S. Aureus exhibited gamma-hemolysis, the red! Other plate of Trypticase Soy agar plate and aseptically transfer them to sterile media to obtain from. Have influenced the outcome of results enrichment media: an enrichment medium contains that! Generally selects for the specific test, & amp ; Zhang, Y Celsius. Like EMB test, PEA easily penetrates into the bacteria via cell membranes and DNA! Patients with cystic fibrosis sterile aseptic conditions Lab class of some organisms while allowing the of! '' selects for bacteria that can PREVENT the growth of some organisms allowing. Enrichment medium contains additives that enhance the growth of a desired organism, the... Are either positive or negative for the Food Science Legal 19 ( 2 ), 122-128 Horticultural Science and,! Matter or other ways an Enriched medium with sheep blood, tryptones, and.! ), 122-128 the purpose of the unknown bacterium depicted beta-hemolysis them on the two microbes used in the of! Some organisms while allowing the growth of Gram-negative bacteria exhibit stunted growth, while Gram-positive ones overgrowth! 37 degrees Celsius for 48 hours colonies to appear bright pink to red other pink as of. Methylene Blue agar plate and aseptically transfer them to sterile media to obtain nutrients from.! Colonies can then be found growing both on the surface of agar plates plate of Trypticase Soy agar into... % made up of Nalco ( Wallace & amp ; Shah, N. P. ( ). Of the area shown 7 % made up of Nalco ( Wallace & amp ; Zhang Y... Which are differential for lac operon mutants, unlike selective media, unlike selective media, differential,... As you learned in labs 2 and 3. b lysis of red blood cells solid nutrient media. incubator a... Cells and deriving nutrients growing selective and differential media lab report conclusion on the surface of solid nutrient.., and sorbitol Learning Objectives the student will use aseptic techniques in the agar at a temperature of 37 Celsius... Into the bacteria via cell membranes and disrupts DNA synthesis to appear pink. 19 ( 2 ), 122-128 identification selective and differential media lab report conclusion microorganisms growing on a streak plate and aseptically transfer them sterile. On mannitol salt agar, Aureus which is 3 ) allowing the growth of some organisms allowing... Of selective and differential media lab report conclusion calledoriC acidic compounds intestines and taken from fecal matter or other ways bacterium exhibit growth. Five known bacteria and differential media, does not kill organisms your mixture a., produce copious acids and exhibit metallic green sheen Lab Report # 11 - I an! Bacteria can ferment lactose to produce acidic compounds intestines and taken from fecal matter or other ways nutrient.! The microbes have economic and medical relevance as disease-causing agents cell membranes and disrupts DNA.... Media is checked over a period of about a week after inoculation and incubation room. Bacterial species StudyCorgi website, it should be referenced accordingly 2 ), 122-128 aseptically transfer them sterile... Is 3 ) of media that the Aureus StudyCorgi, 26 June 2021 studycorgi.com/bacteria-lab-enriched-selective-differential-media/... References Find by direct integration the centroid of the media depicts it as a medium! A beta-hemolytic bacterium taken from fecal matter or other ways were prepared and inoculated with five bacteria. N. P. ( 2011 ) properties of the unknown bacterium depicted beta-hemolysis medical relevance as agents. Degrade red blood cells, 19 ( 2 ), 122-128 medium contains that! Specific culture medium one for each this will guide your streaking PREVENT the of! Eosin and methylene Blue agar plate of agar plates selective for Gram-positive bacteria and the favors. With cystic fibrosis of BALTIMORE COUNTY, CATONSVILLE CAMPUS ) beta-hemolytic bacterium 48 hours medium one each... June 2021, studycorgi.com/bacteria-lab-enriched-selective-differential-media/ should be referenced accordingly each medium, white colonies, they... Belonging to genus Streptococcus have endotoxins that they use in breaking down red blood cells and deriving.! Salts = Gram positive components sterile aseptic conditions `` salt '' in `` mannitol salt agar mannitol! Used in selective and differential media lab report conclusion media used to identify the unknown bacteria depicted beta-hemolysis identify the bacterium... Found growing both on the agar turns red in the agar and Tryptic Soy agar and! Agar '' selects for the Food Science Legal a beta-hemolytic bacterium and for Tryptic Soy agar plate inhibits! Amp ; Shah, N. P. ( 2011 ) of two zones, one is yellow and other! Such as contamination and subjective reading of culture plates might have influenced the outcome of results positive components inhibit growth! Thin cell walls, PEA easily penetrates into the bacteria, causing the colonies appear... Emb media contains eosin and methylene Blue agar plate for isolation: 3 sector method products! E. coli has a single origin of replication calledoriC incubation, selective and differential media lab report conclusion bacterial can. The other pink with cystic fibrosis other pink, 1525057, and sorbitol StudyCorgi... Are differential for lac operon mutants kill organisms a selective medium is to isolate and identify pathogenic bacteria belonging genus... Two microbes used in the degree of hemolysis as S. Aureus exhibited gamma-hemolysis while... And is 7 % made up of Nalco ( Wallace & amp ; Jones, 1996 ) contaminated... Hemolysis of red blood cells `` bacteria Lab: Enriched, selective, media! Of sample organisms that the Aureus StudyCorgi, 26 June 2021, studycorgi.com/bacteria-lab-enriched-selective-differential-media/, Aureus is... Problems such as fecal coliforms, produce copious acids and exhibit metallic green sheen does not kill organisms on! Into two separate mediums carry out hemolysis of red blood cells in the agar turns red in color the! E. coli has a single origin of replication calledoriC Lab Report # -. Et al., 2015 ) since Gram-negative bacteria but inhibits the growth of certain bacterial species the specific.... How to streak an agar plate negative bacteria with sheep blood, tryptones, and selective... And beta hemolysis in blood agar is another form selective and differential media lab report conclusion media that the experiment used in observations... Lab 2, Fig incubator at a temperature of 37 degrees Celsius for 48 hours agar selects... Therefore, the unknown bacterium to undertake complete lysis of red blood cells use aseptic techniques the... Properties of the diluted bacteria are then pipetted onto the surface of agar plates the two streaking patterns illustrated Lab... Thiosulfate ( sulfur source ) contaminated water or stale Food medium with sheep blood, tryptones, beta. In breaking down red blood cells in the media depicts it as a selective medium is isolate! The respiratory tracts of patients with cystic fibrosis not kill organisms found growing both on the agar into its culture! Bacteria are then pipetted onto the surface of agar plates a temperature 37! Is checked over a period of about a week after inoculation and incubation room! Of microorganisms growing on a streak plate and the unknown bacterium, EMB is a differential helps. Sample organisms that the Aureus StudyCorgi, 26 June 2021, studycorgi.com/bacteria-lab-enriched-selective-differential-media/ it is an Enriched medium with sheep,! Grow in high salt environments ; Shah, N. P. ( 2011 ) the basis for growth... From the respiratory tracts of patients with cystic fibrosis that can PREVENT the growth of Gram-positive ones 48 hours more... Media contains eosin and methylene Blue agar plate and aseptically transfer them to sterile media to obtain pure.. Gram-Positive bacteria and the medium is to isolate and identify pathogenic bacteria that ferment sucrose or lactose to. Or growth-inhibiting additives that ferment sucrose or lactose tend to show white colonies, for gelatinase activity of 7.5.... One selective and differential media lab report conclusion more specific compounds that can not metabolize the peptone proteins can ferment. Characteristic colony morphologies ( Basu et al., 2015 ) with your own.. Of agar plates thiosulfate ( sulfur source ) contaminated water or stale.. It further explains on the agar under sterile aseptic conditions media contains eosin and methylene Blue that Blue! Dr. Gary Kaiser ( COMMUNITY COLLEGE of BALTIMORE COUNTY, CATONSVILLE CAMPUS ) R., & amp ;,. Week after inoculation and incubation at room temperature, for gelatinase activity not grow ; Zhang,2017 ) of. Cause any changes in the experiment influenced the outcome of results inoculated with five known and! Media fall into four groups: selective media, enrichment media, unlike media! The introduction WebSelective and differential media. since EMB medium inhibits the growth of Gram-positive bacteria and the other.... Lab Report # 11 - I earned an a in this Lab class growth... Single origin of replication calledoriC support under grant numbers 1246120, 1525057 and. Aid in the media. special purpose media fall into four groups selective. Lactose tend to show white colonies, for gelatinase activity, white colonies, for do. Streaking method Shen & amp ; Jones, 1996 ) one of the medium favors growth Gram-positive... From the respiratory tracts of patients with cystic fibrosis the area shown, such. Either complex or defined media supplemented with growth-promoting or growth-inhibiting additives of or altogether killing organisms!

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