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

MECHOUD M; ALVAREZ O; CAYRÉ E; CASTRO M; MINAHK C; SAAVEDRA L

ANNALS OF MICROBIOLOGY

INST MICROBIOLOGIA

Lugar: Milan; Año: 2017

1590-4261

The present study was conducted to quantify the expression of thesakacins produced by Lactobacillus curvatus ACU-1, a strainisolated from artisanal dry fermented sausages of Argentina.Polymerase chain reaction (PCR) screening indicated the presence ofsakacin G, P, and Q genes in L. curvatus ACU-1. Purification andactivity assays determined that anti-Listeria activity was mainlyassociated to sakacin G, as mass spectrometry analysis revealed asingle peak of 3832.60 Da. Further characterization by quantitativePCR demonstrated that L. curvatus ACU-1 transcription of thesakacin G structural gene was three orders of magnitude higher thanthe others. Interestingly, L. curvatus ACU-1 had skgA1/skgA2 aswell as sppQ genes encoded in a plasmid, while the sppA gene thatencodes for sakacin P was present in the bacterial chromosome.These results point out that sakacin G is the main peptideresponsible for the anti-listerial activity of L. curvatus ACU-1, withlittle or no contribution of sakacin P and sakacin Q. The high levelof expression of sakacin G demonstrated in the present work wouldfacilitate its potential use in food preservation, improving the foodquality, safety, and shelf life. In addition, the sakacin G promotermay serve as an interesting tool for the expression of otherbacteriocins at higher levels.