89D-28 |
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H. LEE, J. J. Churey, and R. W. Worobo. Food Science & Technology, Cornell Univ., New York State Agricultural Experiment Station, 630 W. North St., Geneva, NY 14456-0462 Higher percentages of bacterial isolates from different varieties of honey showed antimicrobial activity against several different food spoilage and pathogenic microorganisms compared to bacterial strains isolated from other food sources. The antimicrobial activity was determined to be proteinaceous in nature, similar to that of bacteriocins. These antimicrobial peptides could be an alternative method to reduce the incidence of foodborne illness and spoilage because of their potent antimicrobial activity. The objective of this study was to purify and characterize the antimicrobial peptides produced by a bacterium isolated from honey that exhibited antimicrobial activity against common food spoilage and foodborne pathogens. A bacterial isolate from honey showing high levels of antibacterial and antifungal activity was selected and the antibacterial peptide was partially purified by ammonium sulfate precipitation followed by Octyl sepharose CL-4B. A single active peptide was purified using RP-HPLC with a C18 column. The purified peptide was subjected to MS spectrometry, N-terminal sequencing and amino acid analysis. The antifungal peptide produced by the same bacterial isolate was purified by a series of C18 and silica Sep-Pak columns using the 65% ammonium sulfate precipitant. The antibacterial peptide exhibited activity only against Gram-positive bacteria. The molecular weight of the peptide was 3138.4 Da, as determined by MS spectrometry. The amino acid sequence of the peptide was deduced by N-terminal sequencing as well as amino acid analysis and did not show any homology to any known sequences of antimicrobial peptides contained within the NCBI Blast databases. The proteinaceous antifungal compound showed activity against a broad spectrum of molds including Byssochlamys fulva, Aspergillus niger and Geotrichum candidum. Its size was estimated approximately 8 kDa by SDS-PAGE and gel overlay. The novel antimicrobial peptides could be highly applicable to food and beverage products to reduce the incidence of foodborne illness and spoilage.
Session 89D, Food Microbiology: Antimicrobial effects on foodborne microorganisms
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |