It aids in the differentiation of species from the genera Corynebacterium, Clostridium, Bacillus, Bacteroides, Fusobacterium and members of Enterococcus . Gelatin hydrolysis test is used to detect the ability of an organism to produce gelatinase (proteolytic enzyme) that liquefy gelatin. This process takes place in two sequential reactions. In the first reaction, gelatinase degrade gelatin to polypeptides. Then, the polypeptides are further converted into amino acids.
The formation of a dye-iodine complex will occur in the cytoplasm. Then, it was flooded with ethanol and washed immediately. It is where the process of decolorization occurs. It should not be prolonged as it can over decolorized and immediate washing would sometimes cause under decolorized smear and. Finally safranins were flooded on slide for 30 seconds and rinse it with tap water and the slide must be dried using a blotting paper before viewing and examine in the
In the Oxidative fermentation tube the media was a differential media that helps determine whether specific bacteria can oxidize or ferment to metabolize glucose. Citrate test checks to see which bacteria could citrate as the only source of carbon. A positive test shows that an alkaline environment ia created and that the pH level rose. The color of the media changed from green to blue if its positive. The Bile Esculin agar test has its medium as selective and differential.
A sufficient amount of this solution was poured into two petri dishes labelled “LB -pGLO” and “LB”. Into two dishes labelled “LB/amp -pGLO” and “LB/amp +pGLO”, the agar broth with ampicillin was poured in. Arabinose C sugar was then added to the broth and was poured into one dish labelled “LB/amp/ara +pGLO”(Fig. 1). They were left overnight to harden.
Then an estimated (by trial and error) 1-3 grams of hydrated copper sulfate was added to a crucible with the lid on top. The total mass of the hydrated copper sulfate was recorded by subtracting the total mass of the crucible, lid, and sample from the mass of the crucible and lid (described in table 1.3). By attaching the wire triangle to the ring, the crucible was able to sit securely while having the bunsen burner underneath. Lighting the burner once again, each substance was heated for several minutes until estimated that the compound had changed color. Once a prevalent color change had been observed at approximately 4 minutes (blue green color) the crucible was set on the counter using the tongs to cool for approximately 5 minutes.
Potato Dextrose Agar 1. 39.0 g of potato dextrose agar powder was dissolved in a litre of sterile distilled water on the hot plate. 2. pH of the solution was adjusted to 5.6 ± 0.2 by adding NaOH or HCl and was immediately transferred into the Schott bottle to be autoclaved at 121 ° C for 15 minutes 3. Prepared medium was stored in 4° C chiller Plate Count Agar or Total Plate Count 1. 22.5 g of plate count agar powder was dissolved in a litre of sterile distilled water on the hot plate 2. pH of the solution was adjusted to 7.0 ± 0.2 by adding NaOH or HCl and was immediately transferred into the Schott bottle to be autoclaved at 121 ° C for 15 minutes 3.
The bacteria were heat-killed, and these respective components were extracted and the composition resulted in being similar to that of DNA. They also treated the bacteria with multiple enzymes, such as trypsin, chymotrypsin, ribonuclease and deoxyribonucleodepolymerase, where it was found that only the deoxyribonucleodepolymerase inhibited the formation of smooth Pneumococcus colonies. [Downie. A. W. (1972)] Thus, they confirmed that DNA was the transformation principle in Griffith's experiments. The Avery and MacLeod experiment was replicated in the laboratories at the University of the Witwatersrand.
MATERIALS AND METHODS Bacterial strains and culture conditions Two S. aureus strains were used in the present study; S. aureus 8325-4 (SigB-) and SH1000 representing a SigB+.strain. Overnight cultures were grown in Luria Broth (LB) at 37°Cwith shaking at 150 rpm. Exposure to antibiotics was carried out as detailed below. Antibiotics Ciprofloxacin were purchased from Sigma-Aldrich CO. 10 mg/ml stock solution of antibiotic were prepared freshly with 0.1N HCl and stored at -20°C. During the experiment we diluted with sterile water 1:10 and 1:100 depending on the different drug concentration.
Disrupting cellular structure is required to release the proteins from the cell. Purification of proteins begins with homogenizing the tissues, then subsequent fractionation and purification of cellular constituents. In this experiment, the source of protein was sprouting seeds. They were homogenized using a sodium phosphate buffer, pH 7, in a blender. After filtration, it was centrifuged.
Anti-bacterial agents kill or inhibit bacterial growth. My conductive research consisted of making agar, growing bacteria that I received from the inside of a human’s mouth and using different toothpastes to see which brands work better. Introducing bacteria What is bacteria Bacteria is a member of a large group of unicellular microorganisms which
After cutting a block of the fungus, we placed it on the petri dished in the section that was appropriately marked for that specific strain. After the four sections were placed, the lid was placed on the petri dish, and then the dish was with tape to keep close, and wrapped in aluminum foil and placed into the correct bin to sit. After two weeks the petri dishes were ready to be observed. We used a toothpick to scrap lightly the top of the agar in the petri dishes, ensuring we were collecting from one of the dividing lines. With the spores on our toothpicks, we then smeared them onto a slide that was provided to us.
After receiving an unknown mixture, the sample was streaked for isolation onto TSA, blood agar, and MacConkey plates. Each plate serves as a first step to identify the unknowns. The TSA (tryptic soy agar) can be used to do a gram stain, which differentiates gram-negatives from gram-positives, based on the structural make up of the cell wall (Carson, 2015). The blood agar plate is used to test for hemolytic activity, which is useful for distinguishing gram-positives. A MacConkey plate is selective by inhibiting the growth of gram-positives and differential due to the fermentation of lactose by certain gram-negative species.
This is due to the fact that n order for the E coli. bacteria to gain either of the traits the plasmid had to be present in the first place, because the GFP gene is inside the plasmid. If arabinose is not in the media in which the bacteria was growing on then the GFP gene could not turn on, thus the bacteria can not glow. This is why the LB/amp/ara plate was the only one to express both traits(antibiotic resistance and glowing). The second part to our hypothesis was that using HIC,GFP would be purified and the final tube would express GFP under an ultra violet light.
This procedure occurred in the presence a Bunsen burner. The inoculation needle were placed within the open flame 15-20 second in order to sterilize the needle and prevent contamination. The needle was allowed to cool 5-10 second before inoculation. Using aseptic transfer technique the needle was used to gather up some of the colonies on the plate, making sure not to touch anything else with the needle. The test tube was uncapped and the lips of the test tube was passed through the open flame three times.