Abstract The transformation principle suggests that bacteria use DNA as their genetic material and are able to exchange their genetic material via a process of transformation. Griffith had theorised the concept of the transformation principle using two strains of bacteria and studied their ability to recombine. Avery and MacLeod followed his studies and suggested DNA was sensitive to DNase, and that the enzyme would destroy the bacteria's ability to exchange genetic material and transform into a new strain. This was then tested in the labs at Wits by second year students where they studied the transformation of ampicillin sensitive E. coli to ampicillin resistant E. coli. The results obtained there were similar to those of Avery and MacLeod,
Inducing Prodigiosin Transposon mutagenesis in Serratia Marcescens Introduction Serratia Marcescens is an opportunistic pathogen, mainly of healthcare facilities but can also be found in many diverse environments. Serratia is a gram negative bacteria which can give it innate resistance to certain antibiotics, especially those that target peptidoglycan cell wall synthesis, due to its outer membrane. In an environment with different microorganisms competing for food Serratia holds a component that gives it another selective advantage. The bacteria contains a red pigment called prodigiosin, that has antibacterial, antifungal, and even antiprotozoal activity. The pigment is produced due to quorum sensing of bacteria, when an appropriate level of N-hex anoyl-L-homoserine lactone (HHL),
However, the isotonic beaker with no NaCl solution did not cause the plant to remain at the same weight, but instead allowed it to take in a bit more water than the hypotonic solution. 5. State your conclusions about the influence of solute concentration on the direction of osmosis. In conclusion, osmosis is highly sensitive to various solutions. Thus, any amount of solute within the water will affect the flow of osmosis and the mass of any plant.
The most common treatment for these infections, caused by Staphylococcus aureus is the antibiotics. There are many kinds of antibiotics using in the modern days, but the first kind of antibiotic being introduced for treating Staphylococcus aureus was Penicillin in 1943. This kind of antibiotic stops the formation of peptidoglycan cross-linkages that makes the bacterial cell well stronger. This eventually makes the cell wall formation and degradation become imbalanced, consequently lead to the cell to die. Other kinds of antibiotic were quick introduced for treating Staphylococcus as well.
These, probably biased, trails showed all the same: no adverse effects associated with rhBMP-2. In the end it appeared that there were ten to fifty times higher risk of adverse events associated with rhBMP-2. (2) The risk of another InFUSEtm-debacle, the cost-effectiveness, stability issues and shelf-life of just 12-24 months. Made the route to the medical market very hard for new comparable uses of proteins in bone substitution. A FDA-approval for this kind of product is hard to get these days after these medical errors (2, 6,
In the past, there had been some speculations that dinoflagellates, which have permanently condensed chromosomes, continuously synthesize DNA throughout the cell cycle (Karentz 1983). Recent evidence, especially from studies using single cell DNA measurements, do not support this hypothesis and indicate a clearly defined S phase (e.g. Bhaud et al. 1991). Interestingly, of all phytoplankton species studied to date, only the dinoflagellate Gyrodinium uncatenum displays a cell cycle with a very long G2 phase (Cetta and Anderson 1990).
Aim of this investigation is to find out how much of an effect there is on enzyme activity and reaction time as pH values change. In this practical, the enzyme that will be used for experimentation purposes is catalase. This molecule is usually found in animal and potato cells, and a substantial amount can be found in any potato extract. The substrate that will be catalyzed is hydrogen peroxide (H2O2,), a common but toxic end product of our metabolism, and highly dangerous if accumulated in the body and not decomposed. It can damage cells if it is not removed.
2.3. Mechanistic studies: Heme binding studies Chloroquine and other quinoline derivatives are believed to show their antimalarial activity by inhibition of hemozoin formation within the parasite food vacuole . Hemozoin was originally considered to be formed by the polymerization of heme , but it has now been demonstrated that it is a crystalline cyclic dimer of ferriprotoporphyrin IX . It is widely accepted that CQ accumulates in the plasmodium food vacuole and binds to some form of parasite heme/hematin, and inhibits hematin polymerization [52-55]. This is a non-enzymatic process in which hematin monomer (heme) released from parasite hemoglobin digestion is converted into hemozoin, also known as malaria pigment.
In the article “Darwin Under the Microscope: Witnessing Evolution in Microbes” the author Carl Zimmer describes the transformation of the study of experimental evolution from the times of Darwin to the experiments that are still ongoing today, as well as how microbes have allowed researchers to observe natural selection and evolution within the lab. When Charles Darwin wrote his famous book The Origin of Species, he believed that natural selection would take too long to be studied within a lifetime. However, that has now changed with the use of microbes. The first research done on microbe evolution happened surprisingly during Darwin’s lifetime by a scientist named William Dallinger. He realized that microbes would be easier to use when trying to study evolution than using plants or animals because of their fast reproduction rate and how small they are in comparison to other possible test subjects.
In this experiment, scientists, Emily Yau and Mona Howell, conducted an experiment that tested how acidity and radiation affects germination of radish seeds. We had hypothesized the seeds that microwave for 5, 10, and some of the 15 second seeds will grow. The radish seeds in the 1 and 2 teaspoons will sprout. We should accept our hypothesis because in the most part, it was correct. Although most of our data supports our hypothesis, some of our data contradicts our hypothesis.
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.
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
Major unknown #202 was given out by the instructor, and the unknown bacterium was streaked out on a Trypticase Soy Agar tube and plate to inoculating the bacterium and incubating. After incubated and grown the morphology was observed and several Gram stains were performed to determinate if the bacterium were gram positive or negative, and the morphology of the bacterium. The Gram Stain of my major unknown #202 was determinate to be Gram negative bacilli, and was double checked by the Gram check slide. Also I noticed that my bacterium was a facultative anaerobe and according to my results of endospore test, my bacterium has not endospores. So according to the list of possible major unknowns provided by the instructor, I narrow my bacterium thru
The normal flora will compete with the foreign bacteria for nutrients and space and has the ability to push out or starve the invader as said in class. In the article, Skin Microbes Help Clear Infection by Anna Azvolinsky, she talks about an experiment conducted by Stanley Spinola of Indiana University whose goal was to analyze the type of ecology found on the human skin and observe the effects it has regarding the skin 's