Cover Page

An investigation on the exposure of UV ray on the rate of growth of bacteria


UV rays were tested on bacteria samples, Escherichia coli  and Bacillus subtilis, which were mostly found in our everyday environment.Both were exposed to UV for different duration to observe how it affected the rate of growth after its has been incubated to grow.We knew that UV rays kill bacteria, but knowing how it affected the growth is not known to a lot of people.We cultured E.coli and B.subtilis colonies and made sure that they were alive. We chose a colony that was healthy and mixed them with nutrient broth. Following that, we spread the two different bacteria with a L spreader on to their respective petri dishes. We exposed 3 petri dishes of each kind to UV ray for 4 timing, 15 min, 30 min, 45 min and 60 min.We collected results which shows that B.subtilis was weaker than E.coli as B.subtilis had lesser colonies compared to E.coli after being exposed for 45 minutes. But both bacteria could not survive after being exposed to UV ray for 60 minutes. This has an implication for medical experiment

No comments:

Post a Comment