CHARACTERIZATION OF PHAGE-LIKE PYOCINS FROM Pseudomonas SF4C

FERNANDEZ, M; GODINO, A; MORALES, G.M.; PRINCIPE, A; FISCHER, S

Mar del Plata

Encuentro; 51 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2015

Bacteriocins are protein produced by bacteria that can kill closely related species. P. fluorescens SF4c is a plantgrowth promoting bacterium that synthesizes bacteriocins (phage-like pyocins), which inhibit the growth of thephytopathogenic strain Xanthomonas axonopodis pv vesicatoria Xcv Bv5-4a. The aim of this work was to characterize the pyocins secreted by the strain SF4c. The complete cluster of pyocins was identified in the genome of the strain SF4c, finding structural genes of the pyocins R and F, as well as, regulatory and lytic genes. The structure of the bacteriocin and its mechanism of action on the sensitive strain X. axonopodis pv vesicatoria Xcv Bv5-4a was studied by atomic force microscopy (AFM). The pyocins presented a structure similar to the bacteriophage tails and they were attached to the surface of the cell to exert their antimicrobial action. The action of the pyocins on the cell was evidenced by a diminution of their volume, observed as a decrease in the height of cell Xcv Bv5-4a in the AFM image. These results suggest that the mechanism of action of these pyocins involve the damage of the membrane of susceptive cells, probably by formation of pores. The characterization of this class of antimicrobial compounds is relevant because of their potential application as biocontrol agent