Recognition of the type of a strain isolated from a patient may be of great importance in epidemiological studies related to the source and the spread of the infection in the community. Nitrate reaction occurs only under anaerobic conditions Fig 8. The reason for identification of unknown bacteria was to help students recognize different bacteria through different biochemical tests and characteristics. Listeria monocytogenes in foods: incidences and possible control measures. The test depends on the ability of certain bacteria to produce indophenol blue from the oxidation of dimethyl-p-phenylenediamine and α-naphthol. Gelatin causes the media to thicken, especially at cooler below 28 oC temperatures.
The strain O157:H7 releases a toxin into the body cavities that initiates an illness in mammals 2. We talked about cell morphology earlier but it is true that bacterial cells are often colorless and therefore you wouldn't be able to see anything under the microscope. The differential ingredient is esculin. A gram stain was done originally and found red rods identifying the bacteria as gram negative. Characteristically, this type of hemolysis is seen as a distinct greening of the agar in the hemolytic zone, and thus this group of Streptococci has also been referred to as the viridans group. This review highlights some common molecular techniques, their advantages and those that have been applied to pathogens isolated from ducks and their related sources. This will reduce the pH of the media.
Therefore, different methods of staining exist to be able not only to see but also to differentiate bacteria. Duck meats and eggs have also been implicated in a number of outbreaks. The science of classification is called taxonomy and deals with the separation of living organisms into interrelated groups. A lab report should not be. Eucaryotic cells can move by means of different locomotor organelles such as cilia, flagella, or pseudopods. More precise techniques are used in some cases but some bacteria remain a mystery. Hanging drop wet preparation can be used to study the motility of bacteria.
Identifying the Bacterium If you have an unknown bacteria and you want to identify it, you'll typically perform a gram stain and then observe the colony appearance and the individual features. Antibiotic resistance, Bacteria, Coagulase 1261 Words 5 Pages Lab Report Microbiology Introduction Bacteria can be found almost anywhere. The inoculation of the culture is made on the agar surface by back and forth streaking with the inoculation loop over the solid agar surface. After depletion of the limited glucose, organisms able to do so will begin to utilize the lactose or sucrose. Iodine turns blue, purple, or black the colour depends on the concentration of the iodine used in the presence of starch. A clearing around the bacterial growth shows that the organism has hydrolyzed starch. If gas bubbles appear, the culture.
The nutrient agar was then incubated at 37°C for 48 hours. This serum, containing antibody against that bacteria is called the antiserum of that bacteria. Bacillus subtilis is positive for starch hydrolysis pictured below on the left. You test this in a cystine trypticase agar tube with phenol red as an indicator. This bacteria can catalyze in many environments which makes it very common and found almost everywhere such as soil, water, humans, plants, sewage and hospitals.
The matrix table can also be used to view the properties of these organisms and to compare their properties. This is a test commonly used when trying to identify Gram-negative enteric bacteria, all of which are glucose fermenters but only some of which produce gas. The gelatin hydrolysis tests for an organism's ability to break down the protein gelatin which is derived from collagen. First, the bacteria mix inside the Unknown 109 tube was streaked across a nutrient agar plate using the quadrant streak technique. The observed results may not be completely identical to the expected results.
The sample on the right below is catalase positive. Catalase has one of the highest turnover numbers of all enzymes such that one molecule of catalase can convert millions of molecules of hydrogen peroxide to water and oxygen in a second. The varying characteristics of bacteria play a crucial function in their identification Hogan, 2010. There are also two intermediate bacterial groups. The acid base indicator Phenol red is incorporated for detecting carbohydrate fermentation that is indicated by the change in colour of the medium from orange red to yellow in the presence of acids.
San Francisco: Pearson Benjamin Cummings, 2007. However, they are laborious, relatively slow and less efficient Keramas et al. If your bacteria grows it is either an anaerobe or a facultative anaerobe. Chemical formula, Chemical formulas, Chemistry 1455 Words 4 Pages 140 Matthew Tuthill Unknown Lab Report Introduction There are many reasons for knowing the identity of microorganisms. Campylobacter in poultry: incidences and possible control measures.