A culture in which only one strain or clone is present. A dichotomous key was mapped out and used during this process. These tests were both negative, which confirmed that culture 2 was Bacillus subtilis. A Catalase test was the performed for clearification. What is a pure culture? As shown in figure 1 above, indicated with a yellow line, each antibiotic tested on unknown microbe 7 turned… Unknown bacteria determined to be Alcaligenes faecalis because of its morphological, physiological and metabolic properties. The results of the Gram stain determined which biochemical test to use in order to identify the microorganisms. This deduction was reached with several bits of evidence.
Gram stains were then performed on these 2 quality controlled bacteria in order to distinguish them apart. Environmental and Industrial Use of Bacillus Subtilis. Some other commercial applications of B. This vial contained two unknown bacteria, one Gram negative and one Gram positive, that required identification. Pseudomonas aeruginosa is a Gram negative bacterium that is commonly found in soil and ground water. The gram stain procedure was performed as directed in the lab manual 1.
These microorganisms can have remarkable abilities such that we cannot fathom. The methods that have been learned thus far for identifying bacteria have been applied to this unknown. Firstly, all of the Gram negative unknown possibilities were rods. I began my quest by conducting a Gram stain on my bacteria. The conversion of the originally red slant and butt of the agar to yellow indicates that 876 Words 4 Pages The purpose of the following study is to determine where the two unknown bacteria acquired in Microbiology lab should be classified in regards to temperature, pH level, and osmoregularity. Lastly casein test was performed, test showed positive result for the break down of casein. Infection primarily occurs from these reservoirs.
Both of these tests concurred with the expected results of B. Gram + bacteria produce bubbles. With the gram stain test, it was difficult to determine if the bacteria was Gram positive rods or Gram positive coccus. The gram positive bacteria was subjected to the following test; First the gram + bacteria was tested on catalase test. Through out the semester in the laboratory, we are able to encounter some of the few microorganisms that we as humans have come into contact with. The results of each test were analyzed by the….
After observation, a sample was taken from the isolated colony on the streak plate and another streak plate was done with that, trying to further isolate the colonies. After 2 days, the growth was examine as to the morphology , color and colony. Identification of bacteria is important because they are not only useful but potentially dangerous as well. However, the researcher felt it was important to perform a battery of tests in order to confidently conclude that the Gram positive unknown was indeed B. We were given a chart with all these Agars and also a flowchart where we were to record the results. Seeing that no negative Gram stains were observed, a different approach was taken.
We just turned in our write-ups and lab journals for our unknowns. Catalase is an enzyme that will take hydrogen peroxide and break it down to water and oxygen. This bacterium is also known by the names hay bacillus or grass bacillus 1. Louis Community College at Meramec, 2011. It is possible to identify a mixed culture by running experiments on the unknown bacteria and taking what we already know and applying it to the results. The methyl Red test was used to show which bacterium would be able to produce a mixture of acids that would ferment glucose.
The plate had contamination, which prevented further testing from happening. It will challenge knowledge and skill in performing laboratory techniques, ability to critically evaluate the information obtained from these techniques, and ability to effectively communicate the information. For the first colony that was isolated from the unknown tube, the gram stain test determined that the bacteria were Gram negative rods. Since one of the colonies from unknown 102 was determined to be a Gram negative rod bacillus , a urea test was performed and the organism was inoculated into a urea tube. The Urea test also had a negative result, which confirmed that the unknown 1 is Escherichia coli.
The slide was viewed on an oil immersion 100x. Introduction The purpose to this lab was to isolate and identify two unknown bacteria from a mixed culture provided to us. These particular reactions helped me to narrow down my choices as to what genus and species of bacteria this could be. It is the period where the individual bacteria are maturing and not yet able to. After incubation at 37°C for 48 hours, isolated colonies were observed and differentiated by their distinct morphologies: both round and whitish, though some colonies were smooth, translucent, convex, and mucoid, while the others were rougher and more opaque. Three choices fit this profile. The reasons range from the 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.