The Effect of Purified Curcumin in Varying Concentrations as an Antibacterial Agent Against the Growth of Escherichia coli

In performing this experiment, the aim was to decide the effect of varying concentrations of purified curcumin, in 0.2 grams, 0.5 g, and 0.8 g increments, based around the 0.5 g recommended daily serving, on the growth, or lack thereof, of Escherichia coli. The results can be used to create easy, organic antibacterial medicines, solutions, and remedies.

To obtain the results, a Vernier Colorimeter was used at a wavelength of 430 nanometers to record the absorbance rates of the solutions, and then the 12 tubes of inoculated solution to the 12 tubes “clean” broth solution were compared over two days to find the difference in absorbance. Three test tubes were allocated for each concentration of curcumin, as well as three tubes with no applied treatment. The higher the absorbance rate, the more bacteria was grown in the solution.

An Analysis of Variance (ANOVA) was used to interpret the results of the experiment. The alpha value to determine significance was 0.05, and the p-value yielded by the tests was 0.074917 on the first day of data collection and 0.063311 on the second day, leading to believe the presence of curcumin does not have a statistically significant effect on inhibiting E. coli growth. However, through analysis of the trends of the data, it was determined that the daily recommended serving of curcumin (0.5 g) is most effective over a short period of time, and more curcumin (0.8 g) is more effective over longer periods of time. Retesting for consistent results is always a good idea for the future.

Research Conducted By:

Zachary Hoisington
Sterling Heights High School

Joseph Maleszyk
Cousino High School