Combating Algae Blooms

Microcystis aeruginosa is a common freshwater cyanobacterium that can form toxic algal blooms that harm other species and the environment. This project studied the effects of the antimicrobial peptide Cecropin A on the growth of M. aeruginosa to assess Cecropin A’s effectiveness as a tool to combat algal blooms and limit their environmental impacts. In this study, different concentrations of Cecropin A were tested on M. aeruginosa, the growth of which was then measured using a plate count. Each concentration of Cecropin A tested resulted in a significant decrease in M. aeruginosa growth compared to the control group, indicating the effectiveness of this peptide at inhibiting M. aeruginosa. Because Cecropin A is a peptide, bacteria can be genetically engineered to produce it for anti-algal applications. This study also analyzed the effects of Cecropin A on the non-pathogenic E. coli K12 in order to study development of antibiotic resistance in this bacterium and determine its feasibility for anti-algal applications such as producing or distributing Cecropin A. The effects of Cecropin A were tested on successive generations to determine if this strain of bacterium can build up a resistance to Cecropin A that would make it a suitable candidate to produce large quantities of this peptide. The results over three 24-hour periods of exposure to Cecropin A seem to indicate a development of resistance to Cecropin A by E. coli K12, suggesting that this bacterium may be suitable for production and/or distribution of Cecropin A for anti-bloom control efforts.