Several laboratory experiments were carried out to determine the species of an unknown culture. During staining, the bacteria was determined to be Gram negative after performing differential Gram staining. The bacteria turned purple. When viewing the bacteria, they were rod shaped and were largely individual rather than in groups. It was determined using deep thioglycolate agar, the unknown culture was inoculated using a prick technique, and the bacteria was determined to be facultative. The bacteria was also inoculated into glucose-phenol red fermentation broth and lactose-phenol red fermentation broth. Both tubes started out red and turned yellow if acid is present. So when the bacteria ferments, it produces an acid and the phenol red turns yellow. There is also a small inverted tube placed inside the tube which indicates whether gas has been produced. Both glucose and lactose tubes turned yellow and produced gas bubbles. The bacteria was also tested to see if it could catabolize the amino acid tryptophan. To determine whether the bacteria can catabolize tryptophan, a tube of broth was inoculated with the unknown and cultured, and then Kovac's reagent was added to the tube. The tube containing the unknown turned red, which is a positive indicator that the unknown is capable of catabolizing tryptophan. Two additional broth tubes were inoculated and cultured to determine whether the unknown organism can ferment glucose by a mixed acid pathway or by the butylene glycol pathway. In one tube, methyl red reagent was added and in the other, Barritt's reagent B was added to the tube, then Barritt's reagent A was added second. The first test is the methyl red test and looks for acid production middle of paper ......e it would be better to use to find virulent strains of E coli in Europe than others probes .Works citedGiammanaco, A., Maggio, M., Giammanaco, G., Morelli, R., Minelli, F., Scheutz, F., et al. (1996). Characteristics of Escherichia coli strains belonging to the enteropathogenic serogroups of E. coli isolated in Italy from children suffering from diarrhea. Journal of Clinical Microbiology, 689-694. Johnson, J., Murray, A., Kuskowski, M., Schubert, S., Prere, M.-F., Picard, B. et al. (2005). Distribution and characteristics of the clonal group of Escherichia coli A. Emerging infectious diseases, 141-145.Microbiology in images. (2013). Retrieved December 3, 2013, from http://www.microbiologyinpictures.com/escherichia%20coli.htmlSilva, R., Toledo, R., & Trabulsi, L. (1980). Biochemical and cultural characteristics of invasive Escherichia coli. Journal of Clinical Microbiology, 441-444.