The corC Gene Influences Bacterial Sensitivity to Two-Peptide Bacteriocin Plantaricin EF

Student Name: 
Alice Gevorgyan
UCD Department: 
Food Science and Technology
UCD Mentor: 
Maria Marco

Plantaricin EF is an antimicrobial peptide produced by Lactobacillus plantarum to eliminate competition for food and resources. The exact mechanisms through which Plantaricin EF (plnEF) causes cell death are not known, but research in this lab (manuscript pending) has suggested that plnEF binds to magnesium channels on a cell’s surface to cause membrane leakage and cell death. The objective of the current study was to provide evidence that corC, encoding a putative magnesium efflux pump, serves as the molecular receptor for plnEF. In order to determine if there was a connection between the corC gene and plnEF susceptibility, two strains of L. plantarum and nine strains of L. pentosus, all of which are very closely related to the plnEF producer L. plantarum strain 8826, were isolated and used for DNA extractions. The corC genes from these isolates were sequenced and their sensitivities to plantaricin were measured using 96-well microtiter plate assays. By combining the data from the sequencing and the sensitivity assay, it was found that sequence divergence of the corC gene was associated with altered sensitivities to plnEF. This research can help clarify the mechanisms through which plnEF acts and fill in some of the immense gaps in knowledge that exist in the understanding of bacteriocins. Eventually, this research can help other researchers turn bacteriocins into a new class of antibiotics and aid in the incorporation of plantaricin into the food industry to provide safer, cleaner food.