Introduction The purpose of this experiment was to apply the knowledge gained from this semester of microbiology. A single, unknown bacterium was provided on a nutrient agar plate. Several microbiological tests were performed using sterile techniques that were learned to determine the identity of the unknown. Tests Conducted The first step to identify the unknown was to isolate the bacteria that was provided. This was done using a streak method on a nutrient agar plate. After one week the bacteria grew, appearing to be small and circular, with a cream-colored pigment. The first test performed was the gram stain. This was done to determine if the bacteria was gram positive or gram negative. After completing the stain and observing the slide through a compound microscope it appeared that the unknown bacteria was purple and rod shaped. At this time it was known the bacteria was a gram positive bacillus. The gram stain was followed with a mixture and then with a simple …show more content…
Test results and the Bergey’s Manual were used to help identify the unknown bacteria. B. Subtilis is a rod shaped, gram positive, spore forming bacteria that are naturally found in soil and vegetation. B. Subtilis is also located in the gastrointestinal tract and on the skin of humans. It is very rare for B. Subtilis to colonize on or in the human body. B. subtilis is not considered pathogenic or toxic and is not a disease-causing agent. B. Subtilis spends most of its time inactive and in spore form. B. Subtilis has been used in the production of antibiotics and probiotics. B. Subtilis is also used in the production of cleaning detergents, chemicals and is currently being used as a fungicide for plant seeds. The proton binding properties of this bacterium play a role in the degradation of radioactive waste and has become the model agent in laboratories because of its easy genetic