Characterization of the heterotrophic bacteria from a minimally processed vegetables plant

- Twenty different species were isolated and Pseudomonas spp. were predominant.
- The isolated bacteria were able to produce virulence factors and form biofilm.
- The conveyor belt was identified as a critical point for increased cell adhesion.
- Some isolated microorganisms are possibly pathogenic or can cause food spoilage.
- The surfaces sanitization with Tego 2000® is effective for bacterial inhibition.

The knowledge on the microorganisms present in an industrial process is crucial to delineate the best strategy 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 and biofilm 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 identified and the conveyor belt in the high care area was found to be a significant source of contamination. Most of the isolates were capable of producing virulence related molecules and all isolates were able to form biofilm. Pseudomonas was the genera with the highest biofilm formation ability, being the predominant microflora along the process chain. Even if no relevant foodborne pathogen was isolated, the results clearly propose that improvements in decontamination during processing are required to effectively control microbial presence in the final product.