CHED 1328 |
| Environmental incompatibility and toxic effects of a majority of biocides used traditionally in the coatings industry have recently caused great concern. A gradual but definite shift to less harsh and more environmentally friendly alternatives is necessary. However, elimination of sufficient amounts of toxic, in-can preservatives coupled with transition to water-based systems leads to more serious problem of “spoilage,” or uncontrolled microbial invasion of these systems because of their intrinsic material properties. A novel approach to this problem is designer polypeptides which demonstrate antimicrobial activities and resist microbial adaptations to changes in the immediate environment. High-throughput, combinatorial chemistry studies in literature have shown hexameric oligopeptides to act as potent antimicrobial agents similar to other peptide families with considerably longer chains. Trifluoroacetic acid and hydrochloric acid salts of hexapeptides Ac-RRWWRF-NH2 and Ac-FRWWHR-NH2 were employed in this study. Antimicrobial potency of these peptides against the bacteria Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were explored. Minimum inhibitory concentration (MIC) and minimum bacteriocidal concentration (MBC) tests were conducted, in which carefully defined samples of bacteria combined with nutrient solution are treated with an increasing concentration of peptide suspended in water to determine the least amount of each peptide necessary for inhibition or elimination of bacterial activity. These results will be compared to those reported in literature. Concentration gradient as used allows for both qualitative and quantitative evaluation of diffusion properties of antimicrobial hexapeptides within systems explored. In addition, as a faster, affirmative alternative to standard microbiological techniques, high-throughput screening techniques were employed to scan for and observe trends in bacterial growth and activity as indicated by varying levels of pyroverdin fluorescence on 96-well microtiter plates. Effective concentrations of both peptides will be used simultaneously in equal molar ratios to identify synergistic effects in systems of interest. |
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Undergraduate Research Poster Session: Medicinal
2:00 PM-4:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |