Peer-Reviewed Journal Details
Mandatory Fields
Hickey, RM;Ross, RP;Hill, C
2004
March
Applied and Environmental Microbiology
Controlled autolysis and enzyme release in a recombinant lactococcal strain expressing the metalloendopeptidase enterolysin A
Validated
WOS: 28 ()
Optional Fields
ESCHERICHIA-COLI LACTIS GENE CHEESE LYSIS
70
1744
1748
This study concerns the exploitation of the lytic enzyme enterolysin A (EntL), produced by Enterococcus faecalis strain DPC5280, to elicit the controlled autolysis of starter lactococci. EntL, a cell wall metalloendopeptidase secreted by some E. faecalis strains, can kill a wide range of gram-positive bacteria, including lactococci. The controlled expression of entL, which encodes EntL, was achieved using a nisin-inducible expression system in a lactococcal host. Zymographic analysis of EntL activity demonstrated that active enzyme is produced by the recombinant lactococcal host. Indeed, expression of EntL resulted in almost complete autolysis of the host strain 2 h after induction with nisin. Model cheese experiments using a starter strain in addition to the inducible enterolysin-producing strain showed a 27-fold increase in activity with respect to the release of lactate dehydrogenase in the strain overexpressing EntL, demonstrating the potential of EntL production in large-scale cheese production systems. Indeed, the observation that a wide range of lactic bacteria are sensitive to EntL suggests that EntL-induced autolysis has potential applications with a variety of lactic acid bacteria and could be a basis for probiotic delivery systems.
WASHINGTON
0099-2240
10.1128/AEM.70.3.1744-1748.2004
Grant Details