Micrococcus Luteus Bacteria

9. After the 48 hour time period the inhibition of the Escherichia coli bacteria around the disinfectant disks was measured. A ruler was used to measure the clearing from the edge of the disk to the perimeter of the clearing. Irregularities in the clearing were not included in the area of clearing.

This experiment illustrates the importance of handwashing and proves that hand washing is worth it. Since our hands are constantly coming into contact with ourselves and others, touching surfaces, grabbing objects, being sneezed into, etc., keeping our hands clean is one of the most effective, yet simple way we can take to avoid getting sick and spreading germs to others. Many diseases and conditions are spread by not washing hands with soap and clean, running warm water. “The human skin is a host to anywhere between 10,000-10,000,000 bacteria per square centimeter and since health care providers come into contact with pathogenic bacteria by being engaged in patient care, hand washing can reduce the risk of spreading diseases (page 3).” The objective of the experiment is to test the effectiveness of hand washing and demonstrate normal flora. This report presents the procedures and materials for the experiment, the experiment's results, and an analysis of those results.

AIM – The aim of the experiment is to determine the relative effectiveness of several anti-microbial substances on developing pathogens. (E. coli)

Micrococcus luteus was first isolated and discovered in 1929 by Alexander Fleming. Is a gram positive bacteria that is commonly found on human skin, water, soil and dust. Since it is an obligate aerobe and thrives in the presence of oxygen, it is also found in the human respiratory tract. It takes the shape of cocci and is often clumped irregularly, in tetrads, or groups of four. It is also non-motile and does not form endospores. Although it has a specific optimal temperature range of about 37 to 45 degrees Celsius, it is halophilic. Micrococcus luteus is also catalase positive, meaning that it produces an enzyme that protects it from any harmful oxygen metabolism by-products (Bergey, 1923).

The aim of this investigation was to find out which antiseptics were most effective at preventing the growth of bacteria.

5.) Inoculate the plate with a lawn coverage streak and place 1 bacitracin antibiotic disk in the

The purpose of this lab was to identify the species of an organism from a given TSB broth culture. Each student was given an unknown sample, and each sample had an assigned ‘sample number’ for post-lab verification by the professor. My sample number was #18. A list of possible organisms was given before any tests were run and a chart with the accepted test results for each organism was given as well. To correctly identify the organism, multiple biochemical tests were performed until enough test results were collected to single out the correct organism from the given list. Also given at the beginning of the lab was each samples results for the VP test (negative for

Hand Sanitiser is a liquid substance that was invented to enable humans to wash their hands without the use of soap or water. Hand Sanitiser was invented by a student nurse, Lupe Hernandez, she thought the idea of alcohol and gel together could clean hands in a situation where there was no access to soap or water. This ‘idea’ was produced in Bakersfield, California 1966. It’s a faster technique to achieve clean hands in a short period of time. Hand Sanitiser kills a variety of pathogens that regular soap may leave behind.

The pre-disinfection of the lab bench showed colonies of bacteria and mold, however, post-disinfection showed neither bacteria nor mold. Because of the smooth surface of the lab bench, when we cleaned the area with disinfectant, the microorganisms were wiped out completely. This not only showed the effectiveness of disinfection on smooth surfaces, but it also demonstrated that the disinfection of lab bench is important task of the lab procedure. The disinfection of lab bench can reduce the risk of potential contamination during the lab when handling microorganisms. Disinfection of the area which is another way to practice aseptic technique will prevent contamination of the samples by other microorganisms, and it will also prevent any microorganisms to leave out from the lab

Being able to control bacterial growth is something that is important in our everyday lives. As shown in the previous labs, bacteria can grow and create colonies extremely quickly especially in the right environments. By acknowledging this, it is then important to get an understanding of how bacterial growth can be controlled by humans. To control microorganisms it means to inhibit their growth (static) and or kill them (cidal) (Kenneth Todar, 2015); therefore since focusing on bacteria the terms bactericidal and bacteriostatic are both extremely important for this lab. One broad method we will use to control bacterial growth is heat. The amount of heat needed to control bacterial growth is different for different species of bacteria (Kenneth Todar, 2015). Bacteria can also respond differently depending if moist heating method such as an autoclave with steam is used, or a dry heating method such as inoculating a loop over a fire is used (Kenneth Todar, 2015). UV works by damaging the cells DNA, without proper DNA, the cells will die and the object

Alcohol is a chemical that is used as an antiseptic and a disinfectant. Alcohol works by denaturing proteins, that start cell metabolism, by messing with metabolism. Alcohol is used in one of my mouthwashes as an antiseptic. This was an important ingredient in my experiment because this was going to tell me if alcohol mattered. Crest the mouthwash that had no alcohol in it did not show the same results as Listerine. Listerine showed excellent results when it came to preventing oral bacteria and Crest wasn’t able to prevent as much

Another purpose of this experiment is to stress the importance of knowing the identity of a microorganism. Knowing the species of microorganism present in a sample provides a

The purpose of the two experiments was to determine the fundamental effects that temperature has on the growth and survival of bacteria. During the first experiment five different bacterial broth cultures of Escherichia coli, Pseudomonas fluorescens, Enterococcus faecalis, Bacillus subtilis and Bacillus stearothermophilus were individually incubated at temperatures of 5, 25, 37, 45 and 55°C for one week in an aim to distinguish the effect temperature has on growth and survival of the five different species. After one week they were observed for distinguishable changes by the turbidity showing an indication of bacterial growth, or the clarity an indication of no survival.

Bacteria, which is the plural form of bacterium, is a large group of unicellular organisms. They are prokaryotes, which means that they do not have a nucleus and other various organelles. They are the smallest living cells, and these cells are both beneficial and detrimental to the human body. However, antiseptics are applied to the epidermis (usually hands) of organisms to decrease the chance of receiving an illness. Antiseptics, such as rubbing alcohol or hand sanitizers destroy bacteria by changing the pH level of the environment that the bacteria remain in. The change of the pH level makes it difficult for the bacteria to survive in the environment it invades. In this lab, we are trying to figure out the effectiveness of these particular antiseptics: Bath and Body Works “Ocean” (A), Germ X (B), Bath and Body Works “I Love Geeks” (C) and no antiseptic (D). The effectiveness of this sanitizers is based on whether they can inhibit bacteria or not.

Microbial growth can be affected by different environmental factors such as temperature, osmotic pressure, oxygen concentration and pH. Six experiments were carried out in this report testing for microbial growth against different environmental factors. Good aseptic techniques were used to prevent contamination, resulting in a uniform set of results that are in line with the literature.