Identification of bacteria within Unknown Culture #21 In this experiment, an unknown culture of two different types of bacteria was assigned to each person, a number of tests were performed to isolate and identify these bacterial cells. Based on knowledge from the previous experiments completed in lab, a basic understanding of each type of bacteria was used to create a flow chart that would aid the process of identifying the unknown bacteria within the culture. A gram stain that is performed initially will narrow down the types of tests certain bacteria will and will not respond to. In addition to the gram stain, some of the tests that were used include, a catalase test, an Eosin methylene blue (EMB) agar test, a bile esculin test, and a 6.5% sodium chloride (NaCl) test. If the catalase enzyme is present in the organism being tested then when in the presence of hydrogen peroxide (H2O2), the enzyme will convert the solution to water and oxygen, this can be observed bubbling of the organism when hydrogen peroxide is added to the test tube. EMB agar is both a selective and differential media; it is selective for gram-negative cells, in that when a gram-positive culture is plated there will be no colonies after incubation because the eosin and methylene dyes prevent the growth of gram-positive organisms, the …show more content…
After 5 days the plates were removed from the cold room and the gram-negative test for Colony A on the EMB agar showed pink fisheye colonies which lead to the conclusion that the gram-negative organism within Unknown #21 was Enterobacter aerogenes. Had the pigmentation been metallic green, the organism would have been identified as Escherichia coli, and had there been no pigmentation at all a Triple Sugar Iron agar (TSI) test among other tests would have been
Staphylococcus epidermis produces the enzyme catalase. In the PEA Agar, a catalase test was performed which showed that the organism produced catalase. Staphylococcus epidermis is not a mannitol fermenter. Mannitol fermenting organisms grow on the Mannitol Salt Agar. The unknown organism is not a mannitol fermenter because it did not grow on the Mannitol Salt Agar.
Transformation in bacteria usually takes place when a bacterial cell accepts strange DNA and integrates to its own DNA. The transformation normally takes place within plasmids, which are tiny circular DNA molecules that have been separate from its own chromosome. The copies of the same plasmid range from 10 to 200 copies within a cell. These copies of plasmids may multiply when the chromosome replicate or multiply independently. One plasmid has a range of 1,000 to 200,000 base pairs.
The tube was placed back in incubation for 96 more hours to observe any more positives. 2.10 Catalase Test A trypticase soy agar plate was used and after incubation, four drops of 3% Hydrogen Peroxide was added to the plate to flow over the bacterial growth. A presence of bubbling was observed. 2.11 Starch Hydrolysis
Materials and Methods To start with, the unknown bacteria # 710 broth had to be successfully isolated on an EMB and MAC agar plate. Using aseptic technique by sterilizing the wire loop with Bunsen Burner between inoculations and flaming the opening of the test tubes before inserting in the loop with the bacteria. The streaking technique used was to isolate the colonies on the agar plates. In addition, the streak plates had to be incubated in a upturned position for 24 hours in a hot temperature incubator at 37 degree Celsius. Bacteria need a favorable condition to grow in.
Staphylococcus epidermidis is the organism that was identified based on the tests that I had conducted. The tests that I used to identify this organism were the coagulase test and the catalase test. My bacterium was beta hemolytic as well. First, a gram stain had to be done to determine whether the organism was a gram positive organism or a gram negative organism. This determined which set of tests that had to be done.
Being able to identify unknown microbes from systematic testing is what makes the field of microbiology so important, especially in infectious disease control. Using the testing procedure laid out by the microbiology field we are able to identify unknown bacteria present in our everyday lives, and along the way learn a lot about their characteristics that separate them from other types of bacteria. Being able to do this is vital in order for us to understand why microbes are present in certain places, how they are able to grow and what restricts their growth, that way they can be combatted if necessary. These techniques for determining unknowns are also important for isolating and testing infectious disease microbes in order to prevent spreading. Another important aspect of being able to identify unknown microbes is the
The Melibiose (MEL), Arabinose ARA, nitrate reduction, and catalase tests were all positive, and the oxidase test was
Tn 4351 was originally isolated from bacteroides fragilis [30] . The transposon was successfully introduced into Cytophaga succinicans, Flavobacterium meningosepticum, Flexibacter canadiansis, Flexibacter strain SFI and Sporocytophaga myxococcoides by conjugation [25]. Tn 4351carries two antibiotic resistance gene. One of the codes for resistance to erythromycin and clindamycin which is expressed in bactroides but not in E.Coli. The other gene codes for resistance in tetracycline and is expressed in aerobically grpwn E. coli, but not in anaerobically grpwn E. coli or in bacteroides.
On April 6, 2016 at approximately 11:45am, a local police station got a call about a hostage situation at a local pharmacy. When police and medical examiners got to each crime scene, they learned that all of the hostages were given drugs and had overdosed on them. Some of the pills, in powder form, were found near the victims. One of the victims was stable enough to tell the investigators that the power on the floor were the drugs they were forced to take. The medical examiner found out each hostage was given either unknown A or unknown B.
Abstract: The purpose of this experiment was to identify given Unknown White Compound by conducting various test and learning how to use lab techniques. Tests that are used during this experiment were a flame test, ion test, pH test, and conductivity test. The results drawn from these tests confirmed the identity of the Unknown White Compound to be sodium acetate (NaC2H3O2) because there were no presence of ions and sodium has a strong persistent orange color. The compound then will be synthesized with the compounds Na2CO3 and HC2H3O2 to find percent yield.
The samples of water would need to be cultured on a buffed charcoal yeast medium. The cultures are keep for a minimum of 14 days before the lab can confirm a negative result. I believe that the Legionella bacteria is the reason why 70 workers in the same building became ill around the same time. Proper water treatment standard in the building my have prevented so many workers become ill and avoided the reported death of one
Aseptic technique was initiated at the beginning of this experiment by cleaning the work surface with disinfected wipes. Personal protectives equipment was also worn. The material utilized in this experiment was: S. epidermidis culture broth, sterile cotton swab, streak plate, forceps in 70% alcohol, a lit tea light, and the three antibiotic disks (novobiocin, gentamicin, penicillin). The first step, I divided a plate into three quadrants and labelled them with the different antibiotic names. Using the lit tea light, like a bursen burner, I flamed the mouth of the S. epidermidis culture.
After experiment on microscope under oil immersion, I learned that my Unknown is gram positive. Under the lens, the bacteria appears in purple color. Its morphology is cocci arranged in cluster. However, during decolorizing process, I put too much alcohol to the crystal violet-iodine complex making the color overly removed. That led to the result of my gram positive has slightly redish
Joshua Miller 12/18/17 Fermentation Lab report Introduction The term fermentation refers to the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat (wikipedia). Sugars are converted to ethyl alcohol when fermentation happens. In this experiment we determined if yeast cells undergo fermentation when placed in a closed flask with no oxygen. Glucose and yeast are mixed together in a closed flask and allowed to incubate for about one hour.
The media used in this experiment was Trypticase nitrate broth. The reagents used (A and B) were sulfanilic acid and alpha-naphthylamine (respectively). Using aseptic technique, the bacterium (16A and 16B) were inoculated into labeled broth test tubes. The tubes were incubated for 48 hours at 37 degrees Celsius. When the incubation was complete 5 drops of reagent A and 5 drops of reagent B were added to each of the broths.