Characterization of the heterotrophic bacteria from a minimally processed vegetables plant

Abstract

The knowledge on the microorganisms present in an industrial process is crucial to delineate the beststrategy for their effective control. The aims of the present work were to isolate, identify and characterize(in terms of production of proteases, gelatinases and siderophores, quorum-sensing inhibition andbiofilm formation) the resident heterotrophic bacteria present in a minimally processed vegetables(MPV) plant where sodium hypochlorite was used for decontamination. A total of 47 isolates were obtained with 49% belonging to the Pseudomonas genera. Twenty different bacterial species were identifiedand the conveyor belt in the high care area was found to be a significant source of contamination. Most ofthe isolates were capable of producing virulence related molecules and all isolates were able to formbiofilm. Pseudomonas was the genera with the highest biofilm formation ability, being the predominantmicroflora along the process chain. Even if no relevant foodborne pathogen was isolated, the resultsclearly propose that improvements in decontamination during processing are required to effectivelycontrol microbial presence in the final product.