Antibiotic resistance is a rapidly growing problem affecting every one of us, both in terms of health care and socioeconomics. Alternatives desperately need to be found. This research focuses on bacteriocins, which are very small proteins that are producedby bacteria when they are under threat, perhaps from other microorganisms competing for resources. These bacteriocins kill certain species of other bacteria very effectively and efficiently. It is hoped this line of research could lead to the development of therapeutic bacteriocins, which could eventually become a replacement for current antibiotics. We looked at the spectrum of killing of bacteriocins produced by Streptococcus pneumoniae, the most common cause of pneumonia. We also looked at different methods of potentially increasing the production of bacteriocins by artificially creating a threat.To do this, we adopted a commonly used experiment to see which bacterial species could kill which others, called an overlay assay. To simulate threat, we added an antibiotic and another chemical. The results showed that S. pneumoniae had a larger spectrum of killing than originally thought and the methods we used did not increase production of bacteriocins.