Biochemical identification of bacteriocins from Enterococcus faecalis 710C

• Author / Creator

  Liu, Xiaoji

• Enterococcus faecalis 710C is a lactic acid bacterium that produces two bacterocins, ent7A and ent7B. Both ent7A and ent7B have strong activity against gram-positive food pathogens including Listeria spp., Clostridium spp., vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA). Mass spectrometry analyses revealed that both ent7A (5201 Da) and ent7B (5207 Da) have formylated N-terminal methionine. The amino acid sequences, structural gene sequences of ent7 from nucleotide position 1-275 and immunity gene were determined. Circular dichroism data suggest that in aqueous solution ent7A and ent7B have 20 to 25% alpha-helical region. Addition of membrane-mimicking reagent (trifluoroethanol) did not significantly enhance the alpha-helical content in ent7A and ent7B. Chiral analysis by gas chromatography- mass spectrometry showed that the amino acid residues elucidated in ent7A and ent7B were all in L-configuration.

• Subjects / Keywords

  • Antimicrobial peptide
  • Bacteriocins
  • Mass-spectrometry
  • Food safety
  • Lactic acid bacteria

• Graduation date

  Spring 2010

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3JD80

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.