Quantification of bacteriocin gene expression in Carnobacterium maltaromaticum ATCC PTA-5313

• Author / Creator

  Balutis, Andrea M

• Carnobacterium maltaromaticum ATCC PTA-5313, which produces bacteriocins carnocyclin A, piscicolin 126 and carnobacteriocin BM1, has been approved for use on meat products to control the growth of Listeria monocytogenes. This combination of bacteriocins is very effective as a biopreservative. It was unclear which of the three bacteriocins is responsible for the antimicrobial effect on meat. The aim of this research was to develop a novel method for detection of bacteriocin gene expression and to use this method to determine the expression of bacteriocin genes when C. maltaromaticum was inoculated onto a ready-to-eat meat product. A novel method to detect bacteriocin gene expression in vitro and on a low sodium ready-to-eat meat product was developed using a modified RNA extraction protocol and quantitative polymerase chain reaction. When C. maltaromaticum ATCC PTA-5313 was grown in broth in the presence of lactate and acetate preservatives, there was no change in gene expression during growth. When C. maltaromaticum ATCC PTA-5313 was inoculated onto ham and stored for 28 days at 4C, the structural genes for all three bacteriocins were expressed. During storage, gene expression decreased relative to a culture grown in broth at the same temperature. Gene expression was monitored every 4 to 7 days up to 56 days of storage on vacuum packaged low sodium ham formulated with or without preservatives and inoculated with C. maltaromaticum ATCC PTA-5313 and a 5-strain cocktail of L. monocytogenes. There was an increase in expression of the piscicolin 126 and carnobacteriocin BM1 genes during the stationary phase of growth of the cultures on ham formulated with preservatives. Overall, bacteriocin gene expression from C. maltaromaticum ATCC PTA-5313 is decreased over storage time when inoculated on vacuum packaged ham, and the presence of preservatives results in higher expression levels during stationary phase than that of C. maltaromaticum ATCC PTA-5313 on ham without preservatives.

• Subjects / Keywords

  • Ready-to-eat
  • Bacteriocins
  • QPCR
  • Gene-expression

• Graduation date

  Fall 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3M902B4S

• 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.