Running head: RESISTANCE OF E. COLI TO 1

THE RESISTANCE OF ESCHERICHIA COLI TO ANIMALIS

Alexander I. Miskimon

Topics in Biology

Joshua Cannon

Summer Ventures in Science and Mathematics

The University of North Carolina at Charlotte

Running head: RESISTANCE OF E. COLI TO PROBIOTICS 1

Abstract:

Probiotics are known to aid in digestion by breaking down complex sugars and thus decreasing the time needed for nutrients to be absorbed from food. However, certain probiotics, like Bifidobacterium animalis, also known as Bifidus animalis, inhibit the growth of beneficial intestinal flora already present in the gut. This leads to health problems like K deficiency, stemming from a lack of E. coli found in the ; the die if exposed to the large concentrations of acetic acid produced by the . If E. coli could be conditioned to resist Bifidobacterium animalis, expensive supplements would not be needed, and large amounts of products, like yogurt containing the probiotic, could be consumed without fear of damaging beneficial intestinal bacteria. This experiment conditioned a strain of

E. coli to be able to withstand acetic acid by allowing it to grow in environments with increasing amounts of the acid until it could resist a solution with 10% acetic acid. At the conclusion of the experiment, the E. coli’s ability to resist acetic acid twice the concentration of household vinegar proved that the new strain could survive much better in union with Bifidobacterium animalis in the gut; the digestion benefits of probiotics could be maintained along with vitamin production by E. coli. Therefore, the experiment was successful in producing a culture of E. coli that could coexist with Bifidobacterium animalis.