Caffeine and Its Effect on Bacteria Growth

Caffeine has raised many health concerns over the past decade. Studies have been performed to observe the effects of caffeine. A previous experiment found that caffeine has an antibacterial effect on Escherichia coli (E. coli). This raises questions about the effect caffeine may have on other species of bacteria. To answer this question we took three species of bacteria (E. coli, Proteus mirabilis, and Caulobacter crescentus), cultured them, and added different quantities of caffeine to a portion of the bacteria samples (the experimental group). We also had control groups which contained bacteria without caffeine. Using a spectrophotometer we measured the growth rates of each bacteria sample over an 18 hour period. Our results showed that the caffeine had an antibacterial effect on all three species of bacteria, with C. crescentus being affected the most. These results show that caffeine can have an antibacterial effect which may be beneficial in regards to our health.