July 20, 2009
Microbiology
Dr. Metera
Lab Report 3: Labs 7 and 8- Metabolism and Biochemical Tests
Abstract This experiment focused on metabolism and biochemical tests. The goal of performing these tests was to differentiate microbes from one another and to compare how metabolic and biochemical processes differ from species to species. The tests performed include: the Fermentation of Sugars Test (sucrose, glucose, and lactose), the Urease Test, the Fermentation of Lactose Test, the Sulfide Indole Mobility (SIM) Test, the Nitrate Reduction Test, the Protein Hydrolysis Test, the Catalase Test, and the Cytochrome Oxidase Test. The microbes that were tested during this lab were: Escherichia coli, Bacillus cereus, the unknown, Proteus vulgaris, Staphylococcus epidermis, Enterobacter aerogenes, the control, and Pseudomonas fluorescens. The microbes tested during these various tests were looking for which would: reduce sulfur/produce sulfate, produce indole, or possess motility, reduce nitrate, and contain protease, catalase and oxidaase. Introduction The purpose of these labs was to observe various metabolic processes by determining the pH of certain bacteria, determining if the bacteria was urease positive or negative, determining which bacteria ferment which sugar(s) during fermentation, and determining if bacteria are lactose fermenters and non-lactose fermenters. Metabolic processes can also be observed by determining if bacteria reduce sulfur/produce sulfate, produce indole, or possess motility, determining which bacteria are able to reduce nitrate, determining if bacteria contain protease, determining if bacteria contain catalase, and determining if bacteria contain oxidase. The tests performed to determine these metabolic processes include: the Fermentation of Sugars Test (sucrose, glucose, and lactose), the Urease Test, the Fermentation of Lactose Test, the Sulfide Indole Mobility (SIM) Test, the