The survival of eight undesired (spoilage/pathogenic) food related bacteria (Citrobacter freundii PSS60,
Enterobacter spp. PSS11, Escherichia coli PSS2, Klebsiella oxytoca PSS82, Serratia grimesii PSS72, Pseudomonas
putida PSS21, Stenotrophomonas maltophilia PSS52 and Listeria monocytogenes ATCC 19114T) was investigated
in mineral nutrient solution (MNS) during the crop cycle of radishes (Raphanus sativus L.) cultivated in hydroponics
in a greenhouse. MNSs were microbiologically analyzed weekly by plate count. The evolution of the
pure cultures was also evaluated in sterile MNS in test tubes. The inoculated trials contained an initial total
mesophilic count (TMC) ranging between 6.69 and 7.78 Log CFU/mL, while non-sterile and sterile control
trials showed levels of 4.39 and 0.97 Log CFU/mL, respectively. In general, all inoculated trials showed similar
levels of TMC in MNS during the experimentation, even though the levels of the inoculated bacteria decreased.
The presence of the inoculums was ascertained by randomly amplified polymorphic DNA (RAPD) analysis applied
on the isolates collected at 7-day intervals. At harvest, MNSs were also analyzed by denaturing gradient
gel electrophoresis (DGGE). The last analysis, except P. putida PSS21 in the corresponding trial, did not detect
the other bacteria, but confirmed that pseudomonads were present in un-inoculated MNSs. Despite the high
counts detected (6.44 and 7.24 CFU/g), only C. freundii PSS60, Enterobacter spp. PSS11 and K. oxytoca PSS82
were detected in radishes in a living form, suggesting their internalization