September17.2013 P.4 Environmental Sources Of Bacteria Purpose: We did this lab to find out exactly which conditions would help to grow a bacterium the best. Materials: • Agar • Petri dish • Cotton • Incubator • Tape • Bacteria Procedure: 1. Mark bottom of Petri dish 2. Split petri dish into 4 sections and label the sections 3. Pour hot agar into dish 4.
With a rod (spreader) that was dip in ethanol and then place under the busen burner in order to neutralize it; we spread the bacteria on every surface area of the petri dish. We wanted approximately 10 minutes for the bacteria to dry off, before applying the antibiotics. The three antibiotics were place in the center of the quadrants and a control was also place in the fourth quadrants carefully. Once this was done we close the petri dish and sealed it with parafilm for more protection for the environment of the bacteria. The two petri dish that contained E. coli and S. Marscensen were placed upside down and allowed the growth of the bacteria to interact with the antibiotics for a week.
What kinds of clinical specimens may yield a mixed flora in bacterial cultures? Oral, Skin, or GI specimens 5. When more than one colony type appears in pure culture, what are the most likely sources of extraneous contamination? Individual colonies can be picked up on the inoculating loop, or straight wire and inoculated in to the fresh agar or brother media References Cowan, M. K. (2012). MICROBIOLOGY: A SYSTEMS APPROACH, THIRD EDITION.
Review Sheet Week 8 Exercise 21.5 Questions 1. Morphology and culturing. Pneumococci are Gram-positive, oval to lancet- shaped cocci that usually occur in pairs or short chains Morphology refers to an organism's structure, form and appearance. Gram stains allow for better viewing of bacterial cell structure 2. Alpha hemolysis 3.
1-2-09 Glowing Bacteria Genes are pieces of DNA which hold the instructions for making proteins. The protein will then give an organism a particular trait. Genetic transformation means changes caused by genes, and requires the insertion of a gene into an organism, in order to change the trait. this technique is used by in many areas of biotechnology. Agriculturally, plants can be genetically transformed to be resistant to pesticides, spoilage, and frost.
The differential tests used to identify the unknown cultures were oxidase, catalase, lactose and sucrose fermentation, nitrate reduction, gelatin hydrolysis, starch hydrolysis, manitol salt, MR-VP, citrate, indole, urease, DNase, and coagulase. The tests performed on the unknown bacteria cultures were all used to determine the identity of the bacteria. Each of the tests performed provided some key information about the bacteria in question and how it functions. All of the tests were performed on every culture, however, as some of the tests were used only for gram (+) or gram (-) bacteria, while others were even more specific and identified only for cocci bacteria. The tests performed and what constitutes a positive and negative test are as follows.
02 April 15, 2014 #7 Enterobacteriaceae, Escherichia coli Staphylococcaceae, Staphylococcus epidermidis ABSTRACT The objective of the Unknown Report is to identify two unknown bacterium based on a series of tests learned in the microbiology laboratory. The tests performed on organism A were Fluid Thioglycollate, Gram Stain, MR/VP, SIM, Simon Citrate, and LB plate. The results for organism A were Facultative Anaerobe for aerotolerance, Gram negative, MR positive and VP negative, the SIM test results were positive for Indole productivity and growth radiating but negative for sulfur production, Simon Citrate negative, and there was no red growth on the LB plate. These tests lead to the discovery of the bacterium Escherichia coli which
2. A simple stain of unknown bacteria was performed to determine that it is a Gram negative culture and morphological characteristics are of short/medium single and paired rods. 3. Inoculate two LB agars, using aseptic technique for all inoculations, with one labeled 25 degrees and the other at 37 degrees. Incubated for 24Hrs, recovered, and checked for optimal temperature for growth of unknown; which was the LB agar at 37 degrees.
Abstract Isolation plays a key part in the identification of unknown microorganisms. To be able to successfully identify an unknown microorganism, it is necessary to have single, isolated colonies as references for the tests. Throughout this report, we will be examining the differences in unknown bacteria types, whether it is Gram Positive or Gram negative and will be looking at ways to distinguish the difference between the various unknown bacteria samples that are going to be used. The ultimate aim of this experiment is to correctly identify the different types of unknown microorganisms provided to us and differentiate their types. To do this, we will be using 8 different widely know techniques, including the use of streak plate, gram
Chapter 18 Worksheet 1: Microbiology http://sci.waikato.ac.nz/farm/content/microbiology.html#types_of_bacteria Go to the link above and read the following sections: Cow’s guts and microbes, Discovery of Rumen Microbes, Why do cows need microorganisms? How many microbes live in the rumen? and What types of bacteria are in the rumen?. 1. The study of microscopic living organisms is termed microbiology.