Our group investigated the question of whether there are any household substances that have antimicrobial properties. For the purpose of this lab, we will consider a substance to have antimicrobial properties if it produces a measurable zone of inhibition within an E. coli culture. A zone of inhibition is the area around an antibiotic disc that contains no bacterial growth. Turmeric was tested because curcumin, the compound that gives turmeric its bright yellow pigment, has well-known antimicrobial properties (ACS). We also tested cinnamon because of its wide range of medicinal uses, including antimicrobial properties (Rao and Gan). Finally, we tested chili powder because capsaicin, the active component of chili peppers, has multiple pharmacological
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As shown in Table 1, the cinnamon (Disk 3) had a zone of inhibition of 4 mm. This suggests that cinnamon has less antimicrobial properties than penicillin. The turmeric (Disk 4) did not show a measurable zone of inhibition, showing that it does not have antimicrobial properties. A measurable zone of inhibition shows that a substance has antimicrobial properties because if E. coli bacteria could not grow around a disk containing the substance, but grew around all the other parts of the agar plate, the substance on the disk likely caused the bacteria to die. In the case of cinnamon, one reason it may have stopped bacterial growth is due to cinnamon bark oil and the bioactive phytochemicals cinnamaldehyde and eugenol, which significantly decrease biofilm formation of E. coli bacteria (Kim et al.) As shown in Figure 1, this effect of cinnamon is supported by a 4 mm zone of inhibition around the disk containing the cinnamon solution. Although cinnamon is shown to have antimicrobial properties, it is not as effective of an antibiotic as our positive control, the known antibiotic …show more content…
Additionally, the cinnamon and turmeric mixtures used were not measured out precisely, so the percentages of the substances in the water are not precise. There was also a source of error seen in the penicillin, which was not supposed to have antibiotic properties against E. coli. Rather, penicillin was originally meant as a negative control, but in the experiment with commercial antibiotics and in our household substance experiment, it killed the E. coli bacteria. This may have been due to contamination by other bacteria within the E. coli, though the exact reason is unknown. Because of the commercial antibiotic experiment, our group mistakenly thought penicillin had antibiotic properties which would always kill E. coli bacteria, and therefore used it as our positive
As shown in Table 1, the cinnamon (Disk 3) had a zone of inhibition of 4 mm. This suggests that cinnamon has less antimicrobial properties than penicillin. The turmeric (Disk 4) did not show a measurable zone of inhibition, showing that it does not have antimicrobial properties. A measurable zone of inhibition shows that a substance has antimicrobial properties because if E. coli bacteria could not grow around a disk containing the substance, but grew around all the other parts of the agar plate, the substance on the disk likely caused the bacteria to die. In the case of cinnamon, one reason it may have stopped bacterial growth is due to cinnamon bark oil and the bioactive phytochemicals cinnamaldehyde and eugenol, which significantly decrease biofilm formation of E. coli bacteria (Kim et al.) As shown in Figure 1, this effect of cinnamon is supported by a 4 mm zone of inhibition around the disk containing the cinnamon solution. Although cinnamon is shown to have antimicrobial properties, it is not as effective of an antibiotic as our positive control, the known antibiotic …show more content…
Additionally, the cinnamon and turmeric mixtures used were not measured out precisely, so the percentages of the substances in the water are not precise. There was also a source of error seen in the penicillin, which was not supposed to have antibiotic properties against E. coli. Rather, penicillin was originally meant as a negative control, but in the experiment with commercial antibiotics and in our household substance experiment, it killed the E. coli bacteria. This may have been due to contamination by other bacteria within the E. coli, though the exact reason is unknown. Because of the commercial antibiotic experiment, our group mistakenly thought penicillin had antibiotic properties which would always kill E. coli bacteria, and therefore used it as our positive