Gram-Positive Bacteria

Bacillus, Coccus, and spirillum are the three main kinds of bacteria. Bacillus are rod shaped. Cocci are spherical shaped. Finally spirillum are spiral shaped.

Bacteria can exist almost everywhere, some are harmless, and some are harmful. There are thousands of different types of bacteria and they fall

I identified Citrobacter freundii, the gram negative rod, by running a series of tests. I began with the Phenol Red Lactose tests, which tests if the organism contains various enzymes that determine if it can ferment lactose. The broth turned yellow after it was incubated, indicating that the lactose was fermented to acid, and there was also gas present in the Durham tube. Since the Phenol Red Lactose Test was positive, I then ran the Phenol Red Sucrose test, which tests if the bacteria contain different enzymes that determine if sucrose can be fermented. After incubation, the broth was yellow, indicating that sugar was fermented to acid, and there was also gas present in the Durham tube. Next, I ran the Sulfide Production, Indole Formation, Motility test, but I was only testing for Hydrogen Sulfide Production to differentiate between the organisms Citrobacter freundii and Enterobacter aerogenes. This test detects if the organisms can metabolize sulfur into hydrogen sulfide, which is revealed by the formation of ferrous sulfide that causes blackening around the growth. The test also reveals if the organism can break tryptophan into indole or migrate away from initial stab area. After incubation, the agar slant was completely black, indicating that the organism produces hydrogen sulfide and is motile proving that it was Citrobacter

Bacteria is a single celled organism, bacteria have evolved to thrive in almost any environment and can be found in almost any substance/surface and also in the human body, only 1% of bacteria is actually harmful.

The main idea of this experiment was to correctly identify the unknown bacteria, #3. Identification of unknown bacteria yields multiple benefits in many different areas in the research of microorganisms. In this experiment I performed many different test dealing with things such as the presence of enzymes, fermentation abilities and different chemical reactions. Observations made from the tests were then compared to a gram negative unknown chart in order to identify the bacteria. Based off of my results and the chart, I concluded the bacteria #3 was the bacteria Escherichia coli. E. coli is most commonly found in the intestines of warm blooded organisms. Most E. coli strands are non pathogenic however, there are strands

The Gram-positive cell wall is composed of peptidoglycans, a thick layer of protein-sugar complexes taking up 60-90% of their cell wall. Peptidoglycan is composed of two glucose derivatives, N-acetylmuramic acid and N-acetylglucosamine alternated and cross-linked by tetrapeptides that is composed of L-alanine, D-glutamine, L-lysine

Gram negative and gram positive bacteria differ from each other in many ways especially in the composition and size of their cell walls. Unlike Gram-positive bacteria, Gram-negative bacteria have a thin peptidoglycan layer surround by an outer membrane. This outer membrane contains many proteins one of them being lipopolysaccharides (LPS), which contributes to the bacteria’s negative charge. One part of this protein is a lipid, called Lipid A, which is considered an endotoxin because this lipid triggers an immune response stimulating fever

For the Gram stain, I used a microscope slide, wash bottle of water, clothespin, and the reagents crystal violet, Gram’s iodine, ethyl alcohol, and safranin to observe whether the organism was Gram negative or positve. The method was placing and heat fixing a loopful of the unknown organism on the slide. The organisms were then stained with crystal violet for a minute, rinsed off, flooded with iodine for a minute, rinsed off, decolorized with alcohol for 30 seconds, and then finally stained with the counter-stain, safranin, for a minute. I streaked the unknown onto a TSA plate and incubated at 35 C. With a pure colony, we performed a second gram stain procedure and inoculated it into a TSA slant. I used BCP Lactose broth and a loop to perform a BCP Lactose test. The broth was inoculated with a loopful of the unknown and incubated

Name one endogenous source of contamination and discuss the modes of transmission from the source to the new host.

　　I did a Fermentation Test where I inoculated 1 tube of phenol red sucrose, 1 tube of phenol red glucose, and 1 tube of phenol red lactose. A positive result for fermentation would be a change of the color (original color is a red color to a yellow color) of the sucrose, lactose and glucose as well as if gas was produced, gas bubble present within the Durman tube inside the test tube.

(ss) E-coli is a good bacteria short for Escherichia coli. It was mentioned before as bad but can only cause disease when the numbers of bacteria are too large or spreads out of the intestinal tract. (2,5) E-coli is found in our intestines and helps us digest food. (5,2) Another helpful bacteria is lactococcus lactis. These bacterium's group in pairs or short chains. Lactococcus lactis produces lactic acid vital to the dairy industry. This bacterium is used heavily in the production of buttermilk and cheese. Almost all forms of cheese are made with a strain of this bacterium. (7) Bacteria is somewhat blamed for being bad but really some bacteria are quite helpful. They make cheese and help our bodies.

The morphology of Klebsiella pneumoniae is a bacillus shaped bacterium, which means it looks like a rod. This bacterium is also a non-motile and Gram-negative. This means that wherever the bacterium was inoculated into an agar, it only grew in that spot and did not grow outwards. Being gram-negative means that the bacterium has a thin layer of peptidoglycan and stains red during the Gram-staining process. Klebsiella pneumoniae is an encapsulated bacterium, where the capsule

Lee and Bishop (2016) have stated, microbes are microscopic, living single-celled organisms such as bacteria, fungi and virus which is non-living. The structure of bacteria that causes disease are the fimbriae, flagella and toxins. The cell wall provides structural support and the cell membrane supports the functions that occur in the subcellular structure of higher organisms. Bacteria are also known as pathogens which cause diseases in plants, insects, animals and humans. Flagella are the long tail-like structures that enable the bacteria to swim or move and it also help the bacteria to migrate to its site of infection and survive. Toxins are very harmful which are responsible for the symptoms and complication of the disease. One of the chronic disease caused by bacteria is tuberculosis (TB). A favourable environment such as time, temperature and oxygen are important to facilitate the bacterial growth.

Bacteria are single-cell microorganisms that cannot be seen by the naked human eye. Bacteria are in many different classifications. Anaerobic bacteria, also known as anaerobes, are bacteria that do not survive with the assistance of oxygen. Generally, in humans they live in the gastrointestinal tract, but are also found in other places outside the body, such as, in soil and water, in foods, and in animals. Some anaerobes are beneficial to humans, although many others can cause sicknesses, such as appendicitis, diverticulitis, and gingivitis. Qualities that are included in anaerobic bacterial infection are nasty smelling pus, abscesses, and the endangering of tissue. An example of an anaerobic bacteria is bacteroides genus, which is both beneficial and harmful to humans. Secondly, is anthrax, a disease caused by bacillus anthracis (bacterium). In most cases, this is a deadly disease that puts both humans and animals lives at stake. With the large amount of financial, and motivational support scientists have present day, researchers have developed an effective vaccine to prevent this disease. Although not all cases of this have been cured and or prevented by this vaccination, many cases have profoundly responded and ended in a much more positive outcome. Coccus is a bacteria that is shaped like an oval or sphere. Cocci are the plural for cocccus, while a single coccus bacterium is referred to as a monococcus. While some can benefit from life, by maintain balance within

Gram-negative and Gram-positive bacteria can be distinguished by conducting biochemical tests. Its growth can be examined on selected mediums containing metabolic inhibitors such as antibiotics. The medias utilized in this project are: media containing the antibiotic vancomycin, Eosin Methylene Blue-lactose (EMB-lactose) agar, and Phenylethyl alcohol (PEA) agar (Holbrook and Leicht 2017). Vancomycin is most effective at inhibiting the growth of Gram-positive cocci (Rotschafer et al. 2005). EMB-lactose agar inhibits the growth of many Gram-positive bacteria and the lactose component of the medium allows for lactose-fermenting bacteria to cause color changes within the medium (Reynolds 2011). The presence of lactose fermenters in the EMB-lactose agar will cause a color change in the resulting colonies based on the strength of their acidity. A metallic green colony indicates that that active fermenters are present. A pink colony indicates that weak fermenters are present. If a bacterial species does not ferment lactose, it will appear white or colorless (Holbrook and Leicht 2017). PEA agar is a selective medium that inhibits the growth of most Gram-negative bacteria species. It does so by interrupting the lipids within the Gram-negative cell membrane, which will affect its permeability to certain molecules. This could result in the intake of materials that are supposed to be blocked and the release of potassium from within the cell, which is necessary for DNA synthesis (Lal and