Abstract:

Much evidence showed that quorum sensing (QS) is involved in food spoilage. Inhibition of QS has the potential
to provide a new targeted preservation procedure. A screening model based on the spoilage potential and characteristics
of specific spoilage organisms in chilled pork was set up. Several biochemical and physiological tests were applied to
exclude undesired strains. Eighty-six strains with siderophere-producing capability were isolated from 116 strains picked
up from Pseudomonas CFC-selective medium with chromeazurol S (CAS) agar assay. Twenty-one strains able to produce
decarboxylase were isolated from 66 strains picked up from double-layer violet red bile dextrose agar (VRBDA) plate with
decarboxylase detection vial assay. Furthermore, the capability of these isolates (86 siderohere+ and 21 decarboxylase+
isolates) to produce N-acyl homoserine lactones (AHLs) was evaluated with a biosensor strain (Agrobacterium
tumefaciens). It was found that 51 siderosphere+ strains and 19 decarboxylase+ strains could produce AHLs. Eleven
of these isolates were identified based on 16S rDNA, including seven Pseudomonas sp. strains able to produce
siderophere and AHLs and four Enterobacteriaceae stains able to produce decarboxylase and AHLs. These strains will
be useful for the further studies on target preservation

Key words: chilled pork, Pseudomonas, Enterobacteriaceae, N-acyl homoserine lactones, siderophere, decarboxylase