Sakacin G is the main responsible bacteriocin for the anti-listerial activity of meat-borne Lactobacillus curvatus ACU-1

ALVAREZ OE; MINAHK C; MECHOUD MA; CASTRO MP; CAYRÉ ME; SAAVEDRA L

ANNALS OF MICROBIOLOGY

INST MICROBIOLOGIA

Lugar: Milan; Año: 2017 vol. 67 p. 615 - 621

1590-4261

The presentstudy was conducted to quantify the expression of the sakacins produced byLactobacillus curvatus ACU-1, a strain isolated from artisanal dry fermentedsausages of Argentina. Polymerase chain reaction (PCR) screening indicated thepresence of sakacin G, P, and Q genes in L. curvatus ACU-1. Purification and activityassays determined that anti-Listeria activity was mainly associated to sakacinG, as mass spectrometry analysis revealed a single peak of 3832.60 Da. Furthercharacterization by quantitative PCR demonstrated that L. curvatus ACU-1transcription of the sakacin G structural gene was three orders of magnitude higherthan the others. Interestingly, L. curvatus ACU-1 had skgA1/skgA2 as well assppQ genes encoded in a plasmid, while the sppA gene that encodes for sakacin Pwas present in the bacterial chromosome. These results point out that sakacin Gis the main peptide responsible for the anti-listerial activity of L. curvatusACU-1, with little or no contribution of sakacin P and sakacin Q. The highlevel of expression of sakacin G demonstrated in the present work would facilitateits potential use in food preservation, improving the food quality, safety, andshelf life. In addition, the sakacin G promoter may serve as an interestingtool for the expression of other bacteriocins at higher levels.