Escherichia Coli, or E. Coli, is a bacterium commonly found in the stomachs of warm-blooded organisms, animal feces, and hot springs. Most strains of this bacterium are not harmful to humans. In fact, it does many beneficial jobs in our system, including producing vitamin K2, digesting food, and preventing the proliferation of harmful bacteria in our gut. O157:H7 is the only type of E. Coli that harms humans, often causing food poisoning, and can be life-threatening. Structure: E. Coli is a rod-shaped bacterium with adhesive fimbriae. It has only one chromosomal DNA and one plasmid. Some strains are able to accept and transfer plasmids to and from other bacteria, allowing E. Coli to survive in stressful environments. Living conditions: This bacterium prefers to live in higher temperatures rather than colder temperatures and thrives at a temperature of around 40 degrees Celsius. . E. Coli can live with or without oxygen and, under optimal conditions, can reproduce in as little as 20 minutes. It grows best at a pH level of 7 and adapts well to our system thanks to its varied and abundant nutrients. Culture Procedure: The way we grew the bacteria was with agar, which is a polymer made up of subunits of the sugar galactose. This is used instead of gelatin because it is quite stronger and bacteria won't eat it. It is prepared by pouring the substance into boiling distilled water and letting it cool. We made sure everything was hygienic and poured the agar into our plates before letting it cool. (Nordqvist, 2011, Medical News Today) (Laurie Usinger, 2012, Bio-Rad Laboratories) Growth stages of bacteria: Antimicrobial: Listerine Total Care was placed in four different plates with E. Coli. The active ingredient in the center of the sheet confirmed our hypothesis as the 100% concentration killed many more bacteria than the other concentrations. However, the 50% and 25% concentrations showed the opposite of what our hypothesis predicted. This doesn't mean that our hypothesis was wrong, but rather that we made human errors along the way. Some errors may have been the cleanliness of our equipment. If the previous group left antimicrobial residues on the items we used, the bacteria were probably affected. We may also have improperly spread the bacteria across the plates, giving some sides a higher concentration of bacteria than others. This would also have skewed our results. Some things we could do to improve this experiment are to boil each piece of equipment before using it and to find a more efficient and equitable way to distribute the bacteria on the plates. Bibliography: