Microbiology coursework

Abstract The first part of the practical involved streaking cultures using different strains of Bacillus subtilis which were then incubated at 37°C. Spore germination was also observed in three strains of B. subtilis by patching them out on agar and incubating at 37°C. Also, two strains of B. subtilis, cultured overnight, were tested for heat resistant spores by conducting serial dilutions of both. Finally an overnight culture of B. subtilis was tested for sensitivity to various chemotherapeutic agents by conducting an agar disc diffusion test and incubating for a week at 37°C. The second part involved analysis of human flora in which samples were taken from the nose and throat and cultured on Vogel-Johnson and blood agar respectively and then incubated at 37°C for a week. The two plate cultures of B. subtilis streaked previously were observed for isolated colonies. The three strains of B. subtilis incubated previously were tested for proper spore germination. Also the viable count was determined for the serially diluted cultures of B. subtilis and the inhibitory zones around each of the antibiotic discs from the previous session were measured. In the third part, the nose and throat cultures were examined for their appearance and Gram staining was carried out for specific identification of the bacteria. The cultures were then re-streaked on nutrient, blood and

  • Word count: 3297
  • Level: University Degree
  • Subject: Biological Sciences
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The aim is to compare brewing techniques in school and industry.

Yeast/Brewing beer. Aim. The aim is to compare brewing techniques in school/industry. Introduction. Brewing. The brewing process begins with the malt being lightly crushed into a coarse powder called grist. The grist is transferred to a vessel called a mash tun where it is mixed or mashed with hot water. This dissolves the starch and allows the enzymes in the malt to convert the starch to sugars. The temperature and time of mashing are critical in determining the quality and characteristics of the final beer. When this process is complete, the mash is transferred to a vessel called a lauter tun where the sugary liquid or wort is separated from the grain residue. The wort from the lauter tun is transferred to a wort kettle where the wort is boiled and the hops are added. Hops are added at the start of the boil to provide bitterness and may also be added near the end of the boil to add aroma and flavour. Boiling sterilises the wort, removes unpleasant aromas and flavours and makes material, which would cause the wort to become cloudy, clump together or "flocculate". The wort is transferred to a vessel called a whirlpool, which uses a high speed swirling or vortex effect to remove the unwanted solids. The wort is sent from the whirlpool via a wort cooler or paraflow to a fermentation vessel. As the wort leaves the paraflow, yeast is added, as well as oxygen to allow the

  • Word count: 1294
  • Level: University Degree
  • Subject: Biological Sciences
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Relate the rates of evaporation of three liquids to the degree of intermolecular bonding within the liquid.

Intermolecular Forces Lab Purpose: The purpose of this lab is to relate the rates of evaporation of three liquids to the degree of intermolecular bonding within the liquid. Method and Materials: Refer to sheet. Observations: Substance T Initial T Final ?T Evap. Rate Methanol 21.4 6.3 5.1 fast Ethanol 23.5 4.7 8.8 medium Acetone 25.4 7.9 7.5 fast Water 23.8 6.9 6.9 slow Isopropyl Alcohol 26 7.5 8.5 medium Glycerine 24.3 20.3 4 slow Analysis: Vapor pressure is the pressure of a liquid that evaporates into a gas. If the molecules were in a closed container, the vapor pressure could be measured by the force of the molecules acting on the boundaries. When the molecules have more energy in them, they would release it with greater kinetic movement resulting in a greater impact when colliding into the boundaries. Thus, this would increase their vapor pressure. Similarly, when molecules evaporate into an open space at a fast rate, they have higher vapor pressure because they have more energy. This is because they've absorbed the most heat from their surroundings so they have the greatest kinetic energy, and require more space to move and release their energy. The energy in them makes the molecules strong enough to break the intermolecular forces they have with other molecules to escape into the air. As molecules absorb heat from their

  • Word count: 1837
  • Level: University Degree
  • Subject: Biological Sciences
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The Building Blocks of Biology

Assignment1 The Building Blocks of Biology Virtual Lab Report Assignment1: Identify two different types of organisms that you have seen interacting, such as bees and flowers. I will also accept experiments based on an organism interacting with its environment, such as that described in your text -- flies and meat. You can investigate the effect of any environmental factor on an organism, these might include light, sound, air quality, food preference, or nutrient quantity or quality. In your Virtual Lab Report, you should include the observation that led you to a hypothesis. Then you should describe the experiment you would do to test your hypothesis. Be sure to include controls, and describe the variables that would remain constant and the one that you want to test. (Remember, you can only test one variable at a time.) Include the type of data you would collect. The next section would be your expected results. Then you need to state what your conclusion would be depending on those results. Finally, do you accept or reject your hypothesis? Introduction: During summer last year, I had a rash, more like pimples only on my right cheek. I thought it was because of the heat. Although this was the first time I ever had such kind of skin problem, I didn't pay much attention. An aunt told me that it could be because of the pillow and not the heat. To my surprise, after basking

  • Word count: 623
  • Level: University Degree
  • Subject: Biological Sciences
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With reference to membrane proteins, discuss the important role of water in defining the shape and function of biomolecules.

Title: With reference to membrane proteins, discuss the important role of water in defining the shape and function of biomolecules. Water plays an important role in defining biomolecules shape and function because it possesses some unique properties. Among these properties the ability to form hydrogen bond and hydrophobic effect contribute most to the shape and function determination of biomolecules. Water is a polar molecule. The hydrogen atoms take on a slight positive charge and the oxygen atom takes on a slight negative charge due to unequal sharing of electrons. A hydrogen bond is an interaction between a covalently bonded hydrogen atom on a donor group and a pair of nonbonded electrons on an acceptor group. Water itself also form H-bond between the adjacent water molecules in order to add stability. Molecules with groups capable of forming H-bond and readily dissolves in water are called hydrophilic. Due to the polar nature and the ability to form hydrogen bond make water a very versatile solvent. This is very important role of waters in biomolecules since most of the chemical reactions that occur in organism require material dissolved in water. The high H-bonding capacity allow it to act a non-electrolytes and dissolve polar compound such as glucose in the body. Water can also act as electrolytes due to the high capacity of hydration shells and high dielectric

  • Word count: 903
  • Level: University Degree
  • Subject: Biological Sciences
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Cellular Respiration - Fermentation of Corn and Malt Extracts

Cellular Respiration - Fermentation of Corn and Malt Extracts Kevin Osemene Abstract The fermentation rates of two extracts, which are ideal for fermentation, were evaluated. Six pairs of test tubes were setup (3 for malt, 3 for corn syrup) in a proper fermentation setup and the carbon dioxide amount was recorded on a 5 minute basis for 30 minutes. It was found that the greater yeast concentration yielded the greater carbon dioxide readings. The control tubes had no yeast in the tubes and yielded no carbon dioxide results. Since yeast is a single-celled fungi that specializes in converting the glucose into the three components (ATP, carbon dioxide, ethanol), it is the main factor behind the results we see. The corn syrup is concentrated with sucrose and fructose and they come together to form glucose. Maltose is a chain of double glucose molecules and that probably explains the results being twice as high than that of corn syrup. Introduction During photosynthesis, plants obtain the light energy and use it to make monosaccharide sugar glucose. This glucose is transformed into sucrose and then taken to other parts of the plant cell. The energy that glucose stores cannot be accessed readily by the cell. The process of cellular respiration transfers the energy stored in glucose bonds to bonds in ATP (adenosine triphosphate) so that it can be used more easily by the cell. As

  • Word count: 1217
  • Level: University Degree
  • Subject: Biological Sciences
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Tuberculosis pathogenesis

Types , Pathogenesis & Clinical Picture of Tuberculosis TYPES • Primary infection • Reactivation TB PRIMARY INFECTION (usually in children) • It is response to first exposure to M. tuberculosis. • Usually pulmonary infection - at periphery of mid zone of lung (sub-pleura) • TB bacilli are engulfed by macrophages - those survive multiply in macrophages ? carried to hilar lymph nodes • Dissemination to other organs through blood stream can occur Cell mediated immunity & Hypersensitivity • Develop 2-6 weeks after infection. • Macrophages containing TB bacilli present to competent T-lymphocytes? lymphokines ? attract monocytes and transform them to activated macrophages ? surround the infected area ? slow down bacterial multiplicaiton. ° Leads to granuloma formation Tubercle (microscopic granuloma) formation at subpleural area Consists of : • Many epithelioid cells (activated macrophages) • Multinucleated giant cells (formed by fusion of macrophages) • Surrounded by lymphocytes ° Known as Ghon focus. REACTIVATION TUBERCULOSIS . Occur due to reactivation of an old focus in elderly due to: • Malnutrition • Diabetes mellitus • Alcoholism • Immunosuppression (AIDS) 2. Inhalation or ingestion of new bacilli CLINICAL FEATURES Pulmonary TB • Low grade fever (evening rise of temp) • Night sweats • Fatigue •

  • Word count: 210
  • Level: University Degree
  • Subject: Biological Sciences
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Identifying microorganisms using differential staining techniques

IDENTIFYING MICROORGANISM'S USING DIFFERENTIAL STAINING TECHNIQUES Introduction: The purpose of this lab is to experience preparing slides and drawing cells that involve the process of differential staining. In this lab we will be using five different microorganisms. In experiment 4 we will use Staphylococcus epidermidis and Escherichia coli. Staphylococcus epidermidis is a gram-positive cocci shaped bacteria that is known to be one of the leading causes of infections, particularly the foreign body infections (Bukhari, 2004). On the other hand, Escherichia coli is a gram-negative rod shaped bacteria that is known to produce and grow in the intestines of animals and humans often from the ingestion of foods or water (Todar, 2008). In experiment 5 we will use Mycobacterium phlei. M. phlei is a gram-positive cocci shaped bacteria that is of the genus Mycobaterium (SteadyHealth.com, 2004). This type of bacteria is one of the hardest to destroy because of the mycolic acids that cover the cell bodies (SteadyHealth.com, 2004). Also, this bacteria is often the cause of human infections but people infected often respond well to anti-mycobacterial therapy (SteadyHealth.com, 2004). In experiment 6 we will use Bacillus megaterium and Clostridium sporogenes. Bacillus megaterium is a gram-positive rod shaped bacteria that produces spores. This type of bacteria is one of the largest

  • Word count: 2026
  • Level: University Degree
  • Subject: Biological Sciences
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Bacterial leaching - The process involved and discusses the advantages and disadvantages of this method of extracting metals from low grade ore.

Abstract The use of bacterial leaching became a reality for the mining industry in the 1950's initially in copper mining and later in gold mining. This report looks at the process involved and discusses the advantages and disadvantages of this method of extracting metals from low grade ore. EXTRACTING COPPER In 1752, at the Rio Tinto mines, it was first noted that blue-green streams of liquid running from the excavated rock left a brown film on the iron implements. This film was pure copper. In 1947 it was discovered that this was caused by micro-organisms (Merson,J. 1992). Thiobacillus ferro-oxidans and Thiobacillus thio-oxidans thrive by oxidising Fe2+ ions and S2- ions. By spraying the low-grade ore left by traditional mining methods with an acidic leaching solution containing these bacteria results in the conversion of the insoluble sulphide materials into a solution containing CU2+, Fe2+,, Fe3+ and SO42- ions S2- ions are present in copper and the oxidisation of these by bacteria releases the metal ions into a solution. Extraction of copper by this method is known as bacterial leaching and produces a solution of copper sulphate which is diluted and impure (Chemical Storylines). Solvent extraction techniques are used to recover the copper ions from the solution by a process of ligand exchange solvent extraction. (Article 2) The ligand, dissolved in an

  • Word count: 1067
  • Level: University Degree
  • Subject: Biological Sciences
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Urinary Tract Infections: The Pathogenic Traits of Proteus mirabilis.

Urinary Tract Infections: The Pathogenic Traits of Proteus mirabilis Sarah Padley ABSTRACT Three pathogenic traits of Proteus mirabilis were looked at. P. mirabilis differentiates from a swimmer state to a swarmer state when in the urinary tract to enable it to migrate up the urinary tract. Chemotaxis enables the cells to determine which direction the kidney is. This investigation found that amino acids gave no chemotactic response, but that certain chemicals did. HCl, KOH and FeSO4 acted as chemorepellants, with glucose and pH7 being chemoattractants. INTRODUCTION Urinary tract infections are common and diverse. Most infections are not serious and are short-lived. Proteus mirabilis is a common soil organism that can cause urinary stones, acute pyelonephritis or cystitis when it infects the urinary tract (1, 2). P. mirabilis has many unique pathogenic traits, but I shall only investigate a few of them. Traits investigated include cell morphology (because it is unique), chemotactic response to amino acids and chemicals (to see how motility is affected), and attachment to eukaryotic cells (to mimic how it might attach in the urinary tract). METHOD . Proteus mirabilis identification Urine samples were spread onto CLED agar plates (prevents swarming of Proteus) and blood agar plates (identifies hemolytic strains) and incubated overnight at 37oC. Characteristic Proteus

  • Word count: 2107
  • Level: University Degree
  • Subject: Biological Sciences
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