Lab Report On Microbial Unknowns Essay

31 October 2011 Identification and observations of Citrobacter Freundii Introduction Citrobacter Freundii is a species of bacteria that can be potentially harmful to humans. It is known to cause meningitis by protruding into the brain and replicating itself (1). The Citrobacter species has also been found as a cause of some urinary tract infections, diarrhea, and even gastrointestinal diseases and symptoms (3). C. Freundii can be located in a wide variety of soils and water (3). Lastly, it is also the cause of many nosocomial infections due to its presence in water (1).

UNKNOW BACTERIA LAB REPORT UNKNOWN 36 Introduction The purpose of this lab was to identify two unknown bacteria from a mixed culture. The reason for identification of unknown bacteria was to help students recognize different bacteria through different biochemical tests and characteristics. This is important in the medical field because identification of unknown

Lahela Correa 12/08/2009 Microbiology 140 Matthew Tuthill Unknown Lab Report Introduction There are many reasons for knowing the identity of microorganisms. The reasons range from knowing the causative agent of a disease in a patient, so as to know how it can be treated, to knowing the correct microorganism to be used for making certain foods or antibiotics. This study was done by applying all of the methods that I have been learned so far in the microbiology laboratory class for the identification of an unknown bacterium.

Materials/Procedure: The following tests according to the lab manual were performed: gram stain, fermentation tubes, methyl red, vogues proskauer, sulfur, indole, motility and growing it up on MacConkey agar. The gram stain was performed incorrectly the first time. This is because the decolorizer was not on the bacterium slide for long enough, giving a false outcome.

Then the following differential tests were performed: Gram Stain Test: Two smears of the unknown bacterium #5 were inoculated while the second smear was used for a back up. The unknown bacterium dried for at least forty minutes. After the smears dried, the slides were heat fixed two times to ensure the stability of the organism. The slide was placed on top of the staining rack then over the small sink.

| Gram Negative Unknown | Biology 3444-006 | | Lena Wallace | 11/7/2011 | | Abstract: The purpose of this lab was to identify an unknown bacteria culture using differential tests. The identification of the unknown culture was accomplished by identifying the bacteria based on its specific metabolic characteristics and morphology. It is suggested that culture 11 is a sample of Enterobacter aerogenes.

In the world of microbiology it is vitally important to be able to discern the identities of microorganisms. Not only is it important in a lab setting but as well as in healthcare in general. Properly identify what strain of bacteria a person has will aid in the proper medicine and dose given. Throughout the semester we have learned about different types of bacteria and certain test that can clearly identify them. The purpose of this lab report is to identify a Gram-positive or Gram-negative bacterium. Using all the knowledge of procedures and lab techniques identify the unknown and discuss all the tests you performed.

Abstract This experiment is about bacterial growth. We will demonstrate a bacterial growth curve using a closed system. Bacterial growth usually takes up to 12-24 hours to get an accurate result so we will be monitoring this growth between two classes. We also used different methods to determine bacterial growth as well as a few different calculations. One way of receiving data is by using a spectrophotometer where we will record the absorption at a given time to create the bacterial growth curve. We also used the plate count method after performing a serial dilution to calculate the actual cell density at different times given. By using this method we can count the population number of the same given and see the maximum cell density

1. Title: The Process of Determining the Unknown Bacteria #9 Rachel Judecki July 5, 2011 2. Introduction: Each student was given unknown bacteria and was instructed to perform a variety of experimental tests that would help to identify their bacteria. During the process of identification, the unknown bacteria was added to many different testing medias using aseptic technique. They are as follows: lactose fermentation on eosin methylene blue (EMB), TSI (Triple Sugar Iron agar), Phenol red sucrose, the SIM test, H2S by SIM, IMViC (indole, motility, voges-proskauer, and citrate), Urease (urea broth), PDase (Phenylalanine Deaminase), Lysine Decarboxylase, and Ornithine Decarboxylase. Colonial morphology on EMB was used to

1. What does the blood agar select for? |bacteria, or |enterococci | | | | |greenish/gray hue | | | | | |around | | |EMB Agar | |Distinguishes bacteria that ferment |Dark blue colonies with|E. coli and P. |

In the medical field which I am going into, it is very important to be able to identify bacteria. By identifying bacteria, we can prevent, diagnose its presence and determine what is the appropiate treatment to treate the diseased caused by them. For example, if a patient is complaining of a sore throat we can take a sample of the throat to determnne what bacteria if any is causing the pain. Once the bacteria has been identified the patient can be prescribed the appropiate antibiotic. Another reason why is so important to identify bacteria and to know its characteristics, is for pharmaceutical companies to come up with medication and to decided the type of vaccines that can be used to counter it.

The purpose of the gram stain test is to see if an organism is gram negative or gram positive based on it’s color and shape. Using an inoculating loop and inserting it into the incinerator for 10 seconds, it was sterilized. A small drop of water was then applied onto a clean glass slide by using the now sterile inoculating loop. The loop was used to spread the organism back and forth on the slide until a good portion of the glass is covered. The organism and water were left to dry completely before heat fixing the glass slide. After heat fixing, over a sink crystal violet was applied to the glass slide for one minute. It was then rinsed with water and iodine was applied for one minute. The slide was then rinsed with water and 95% ethanol was

In this lab experiment, students had to create a growth curve for E. coli. The E. coli growth curve would illustrate the progression of the population of E. coli a set time period. In this case, the growth curve depicted the population of E. coli over a 12-hour period. The growth curve for E. coli was created from the absorbance levels, the optical density(OD), recorded from the spectrophotometer.

Each mixed culture that was tested had one gram positive and one gram negative bacterial species. The possible species of bacteria that could have been isolated from the mixtures included the following: Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Salmonella enterica, and Pseudomonas aeruginosa. The identities of the unknown species were determined through comparing the experimental data against data acquired from earlier experimentation.

seconds and re-examine the slide. Note Shape and colour and any other observations. Results and Observations: It was evident by visual examination that the alcohol was de-colouring or a least partially de-colouring the bacteria. The sample appeared a dark pink or close to violet by the naked eye; a