Gram positive organisms are susceptible to antibiotics such as penicillin (Introduction to Penicillins, 2012). This is because, gram positive bacteria have a thick layer of peptidoglycan, a sugar and peptide coating that gives a cell its shape and helps it stay intact (Wiley, 2004). The original antibiotic, penicillin, and the likes are used to treat infections caused by bacteria that are gram positive. Based on the scope of the experiment and the materials needed, a budget estimate of $1,000.00 would be needed to buy reagents and materials for this experiment.
Differential media allows for the differentiation between two similar micro-organisms through how the bacteria may handle certain compounds found in the media or the different reactions that may take place when the bacteria is exposed to the medium (3). Selective media on the other hand allow only certain microbes to grow. This is due to the plate containing a limited amount of nutrients, compounds and chemicals that will deter the growth of certain bacteria (3). Dyes, antimicrobial substances, salts, certain growth inhibitors and, antibiotics are also found on this type of medium (3). The differential and selective media mentioned in this lab are as follows:
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.
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
After the results from the three experiments, it has been concluded that Vial B contains the living organisms. This is because in each of the experiments, a characteristic of life was tested. Vial B tested positive and proved that it contained the living organisms.
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.
Introduction Our world is composed of many bacteria’s’ that can either help or destroy us. Therefore, its’s imperative to learn and study them. The purpose of the lab was to put into action the methods that have been learned in the laboratory to determine our unknown bacteria. Bacteria’s can have different features, shapes, and or arrangements that help microbiologist determined their role in our life (whether they are good or bad for humans).
As seen in figure 1 with the pictures of E.Coli in 24 and 48 hrs, there was an increase in diameter for each of the antibiotics except for Penicillin and Tetracycline. The picture of the B.Cereus petri dish after 48 hrs was not taken, however it is shown in the petri dish after 24 hrs that each antibiotic disk formed a zone of inhibition. There was no zone of inhibition around the control disk, meaning the zones of inhibition could be attributed to the antibiotics. The data from Table 2 are the measurements for each sample. Each sample had an increase in diameter except for Penicillin which stayed at 5mm for both bacteria and Tetracycline remaining at 19mm in the B.Cereus sample.
The morphology of the bacteria is a rod shape. Through this experiment, it can be concluded that the bacteria is a Gram negative species. The selective and differential plates were left to incubate and after viewing the results, there was no growth on either of the plates. On the MAC plate, there is a bit of discoloration of the phenol red pH indicator. Though there was a bit of discoloration, it is not a strong enough indication that the bacteria reacted with the agar because there was no growth.
Selective medium involves medium with environmental conditions that specifically grows some microbes while inhibiting others. Differential medium is used to identify and differentiate (as the title says) closely related microbes based on growth responses and physical indicators. It is imperative to use laboratory positive and negative controls in identifying the unknown because it confirms and compares the results of the unknown’s response to the definite guide. While performing the procedures in this report, students had to keep the bacterial and biological species concepts in context. The bacterial species concept is the identification and naming of microbes based on relating physical and physiological features of the unknown to the fitting taxa.
This test was conducted utilizing aseptic technique. I first properly labeled the test tube and aseptically inoculated an MR-VP broth tube with unknown bacteria number 5 using a sterile inoculating loop. After 4 days of incubation, I added 4 drops of methyl red ph indicator to the tube. The contents of the test tube turned yellow in color. This indicates a negative test result because unknown bacteria 5 utilized the butanediol pathway instead of the mixed acid fermentation pathway.
The importance of this experiment stems from E. Coli’s factors. E. Coli is known to be a predominant coliform and they cannot endure living in non-enteric conditions (Megraw and Farkas 1993). Since this bacteria can form diseases in the body, it is critical to distinguish
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.
The purpose of this lab was to test the effect of pollution on algae growth. Through a series of experiments that lasted a month, four of the six hypotheses were proven to be correct or partially correct. The first hypothesis stated that if 0.5 mL of salt was added to algae, then the algae would grow slower than the positive control. This was proven correct, as shown by the difference of the data from the positive control and the container with 0.5 mL of salt in it.
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.
