6. Wash, dry and observe under oil immersion lens. Differential stains render one type of microbe one colour and other types of microbes another colour. In the Gram stain, Gram positive organisms retain the primary dye complex (crystal violet-iodine) whereas Gram negative cells loose the primary dye complex during the challenge rinse. Most differential stains have a challenge step that follows staining with a primary dye.
To conduct the oxidase test I first obtained an oxidase strip. I laid the oxidase strip on a paper towel. I withdrew a sample from my culture using and my inoculating loop and rubbed it on the strip. I waited for about 30 seconds and observed the strip turn purple. The Eosin Methylene Blue Agar (EMB) is used for isolation of fecal coli form.
These include anaerobic conditions (such as rotting carcasses or canned food), warmth, and mild alkalinity. The photo shows the bacillus shape of the bacterium C. botulinum. After germination, clostridial spores release neurotoxins. There are 7 antigenic types of neurotoxins, classified as A through G. Typically, different neurotoxin types affect different species. Only a few nanograms of these toxins can cause severe illness.
INTRODUCTION: Acids Acids are any chemical compound that, when dissolved in h2o (water) gives a solution with the pH below 7.0. Acids are sour, they also destroy chemical properties of bases. Acids conduct an electrical current through them. Common Acids Acetic acid is found in vinegar. Vinegar is used for cooking things, treating jellyfish stings and pickling.
Microbiology lab : task 1 Western Governors University Microbiology lab : task 1 The Methyl Red Test is used to identify bacteria according to their pattern of glucose metabolism. Phosphate buffers, glucose, and peptone make up the Methyl Red broth. Bacteria that produce mixed acids decrease the Ph of the broth. Non-acid end product producing bacteria do not decrease the Ph. Methyl Red turns red for a PH that is lower than 4.4 and it turns orange for a Ph between 4.4 and 6.0.
This kind of Staphylococcus aureus is called “MRSA”, referred to methicillin-resistant S. aureus. This bacteria are multi-resistant to beta-lactam antibiotics, meaning that they are resistant to different kinds of antibiotics, such as penicillin, methicillin, dicloxacillin and cephalosporin. As the process goes, that normal Staphylococcus aureus are being killed by penicillin antibiotic, and the ones that are resistant survived and keep on reproducing, Staphylococcus aureus bacteria that is penicillin resistant spread in the community and its amount kept on increasing. This made natural selection to occur, which the bacteria that are antibiotic resistance are suitable ones and they survived in
Title: Water Potential and Osmosis Aim: To determine the solute potential of plant cells Discussion: The aim of this lab was to determine and observe how six different solutions of varying sucrose concentration affected the epidermis of an onion in terms of the solute potential. Onions are made up of 89% water and 8% to 9% soluble sugars, the rest is minerals, fats, proteins, and sulphur compounds. The solute potential (ψs) is the reduction in the water potential of the solution in the cell due the presence of particles dissolved in the solution. The presence of solutes in water causes the solute potential to decrease and it reduces the free energy of water. This is so because water molecules will tend to bind to the solutes rather than moving freely and away from the solution.
| Practical Report | | | | Practical Report Introduction This specific experiment will demonstrate both the efficiency and the disinfecting capabilities of the various disinfectants used and if the experiment is followed correctly the results deemed should be noted that if the substance possess a chemical substances that inhibits the growth of the bacterial culture placed onto the agar (E.Coli) that inhibition zones will be created and we can tabulate and record the observation thus walking away with an understanding of the efficiency of the tested disinfectants used and their success rate. What is known about E.Coli is that it is normally found in food it is a Gram negative, rod shaped bacterium that can help the body break down and assists the body in digestion of food (Dowshen, 2009).Although certain strains of the E.Coli are pathogenic to humans such as the serotype O157:H7, this specific strain of E.Coli is known to cause food poising and can escalate and become life threatening (Nordqvist, 2011). Domestos is chlorine based bleaching agent (Directa, 2009) and is a common household cleaning substance that is used. Handy Andy is a common and popular general house hold cleaner. Dettol is trusted antiseptic and disinfectant and is widely used to fight unwanted bacteria (Thompson D. M.) It has a distinct and characteristic phenolic odour.
Thus, the pink purple colour of potassium permanganate will be reduced into manganese ions. When the glucose acts as the reducing agent, this means the manganate(VII)ions will act as the oxidising agent. Thus, it will accept electrons and undergo reducing process that lead to the formation of the colourless solution. The equation for this reducing reaction is : MnO4- + 8H+ + 5e - ͢ Mn2+ + 4H2O In the experiment, sulphuric acid is added together with glucose and pottasium permanganate. This is because sulphuric acid acts as the catalyst to the reaction inside the solution.
Beetroot appears as a dark red/ purple colour and this is caused by the betalain pigment, which is contained within the vacuole of beetroot cells. In order for the betalain to leave the cell it needs to pass through 2 different membranes; the membrane bounding the vacuole and the membrane enclosing the cell. In this investigation I want to find out the effect that temperature has on the movement of pigment through beetroot cell membranes. By heating beetroot slices at different temperatures I hope to find out how this heat effects the cell membrane, and I will measure this by testing the absorbance of the beetroot pigment from a sample pot. I will apply this heat by placing the beetroot slices in a water bath that has been heated precisely to a certain temperature.