To identify an unknown bacteria, there are many tested that have to be performed. By keeping record of each test it is relatively easy to compare it to the outcome of other organisms in order to better determine which bacteria you have. When performing these tests and recording them I have realized that you may not always get the same results from your unknown as your organism you think it may be. That is why eighteen different tests are performed so that you can compare your results with the table of possible unknowns. My unknown bacterium after performing the tests and comparing the charts is identified as Bacillus cereus. Bacillus cereus is a bacterium that grows best around 30-37°C. B. cereus cannot grow in high acidic, below pH of 4.5, or high alkaline environments of a pH above 9.3. You are likely to find this organism in the soil. This bacterium is able to form spores and therefore can withstand very harsh environments. This bacterium is commonly associated with food borne illnesses. To cause illness a large number (approximately 1 million bacteria per gram of food) of bacteria must be consumed. This occurs when food is left out and the temperature of the food then ranges from about 4°C to 60 °C. This range is known as the Temperature Danger Zone. This is most likely to happen on buffets at parties, barbeques and picnics.
There are two illnesses that are associated with B. cereus. These two types are emetic and diarrheal. The emetic illnesses cause vomiting. This illness is caused by a head and acd stable toxin produced by the bacteria B. cereus in the food before it is consumed. The emetic type is usually associated with foods that have starch in them such as rice, potatoes, cheese, and pasta. This illness occurs within a time frame of 1-6 hours after the contaminated food has been eaten. Symptoms of this type of illness are nausea, vomiting, and abdominal cramps. The diarrheal illness occurs when a less stable toxin is releases when B. cereus cells...
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