Inhibition Of Antibacterial Substance By Bacillus Atrophaeus 297 Against Susceptibility Of Quorum Sensing Signal Molecule DKPs

Quorum sensing(QS)is a phenomenon in which the number of bacteria reaches a certain density and then uses their own secreted signal molecules to exchange information.And quorum sensing is involved in the regulation of food corruption.Previous studies have shown that Escherichia coli,Staphylococcus aureus,Salmonella,Shigella,and Listeria monocytogenes can secrete DKPs signaling molecules without researching exogenous signaling molecules.In view of this,in this research,the effects of exogenous signal DKPs on the spoilage of spoilage bacteria and spores were studied by the growth,adhesion,biofilm formation ability,protease activity,migration ability and extracellular polysaccharide content of spoilage bacteria.The effect of bacteriocin on the rosive ability of quorum sensing signal molecule DKPs.Finally,the mixed suspension of 5 spoilage bacteria,the signal molecule DKPs and the Bacillus atrophus 297 bacteriostatic substance(CP 297-AE)were sprayed on the orange at the same time,and the CP 297-AE was determined by measuring the microbial indicators and physical and chemical indicators of the orange,affects the orange spoilage caused by the signal molecule DKPs.The results obtained from the research are as follows:By analyzing the spoilage ability of the signal molecule DKPs and spore bacteriostatic culture,it was found that the addition of exogenous signal molecules promoted the growth of five spoilage bacteria,compared with the simultaneous addition of the signal molecule CP 297-CFE.The addition of 297-CFE inhibited the promotion of the growth of spoilage bacteria by the signal molecule DKPs.Compared with the spoilage bacteria with added signal molecules,the biofilms of spoilage bacteria cultured with DKPs and CP297-CFE were slower.For example,when Escherichia coli was cultured at 36 h,At the same time,the amount of biofilm added to the signal molecule and CP 297-CFE was only 74% of the culture of the added signal molecule.Compared with the spoilage bacteria added with signal molecules,the adhesion ability of spoilage bacteria cultured with DKPs and CP 297-CFE was significantly weakened.For example,when Shigella was cultured to 48 h,The adhesion of the signal molecules and the simultaneous application of the signal molecules and CP 297-CFE on the tube wall were 8.62 CFU and 7.48 CFU.Compared with the spoilage bacteria to which the signal molecule was added,the protease activity of spoilage bacteria cultured with DKPs and CP 297-CFE was significantly weakened.Compared with the spoilage bacteria added with signal molecules,the ability of the bacterium with DKPs and CP 297-CFE to be cultured is significantly weakened.For example,when the Shigella was cultured to the 36 th hour,the signal molecules and the simultaneous application of the signal molecules and the diffusion radii of the CP 297-CFE Shigella were(90 ± 0.1)mm and(43.6 ± 0.1)mm.Compared with the spoilage bacteria added with signal molecules,thecontent of extracellular polysaccharides of spoilage bacteria cultured with DKPs and CP 297-CFE was significantly reduced.The results showed that the addition of CP 297-CFE significantly reduced the growth of DKPs against spoilage bacteria,adhesion,biofilm formation,protease activity,migration ability and extracellular polysaccharide content.The spoilage bacteria liquid,signal molecule and spore bacteriocin were applied to the orange.The microbial index and physical and chemical indicators of the orange were determined to study the effect of bacteriocin on the orange spoilage caused by the signal molecule DKPs.Studies have shown that sprinkling spoilage bacteria on oranges can accelerate the decay of oranges compared to oranges preserved in sterile water;simultaneous spraying of spoilage bacteria and signaling molecules is stored compared to oranges stored with spoilage bacteria.The oranges are more corrupt,indicating that the signaling molecules can accelerate the growth of spoilage bacteria induced by food groups,increase their ability to corrupt and accelerate food corruption.After the application of bacteriocin,the signal molecule has a significant effect on the promotion of food spoilage,so bacteriocin has a significant inhibitory effect on the erosion of orange caused by the signal molecule DKPs.In summary,the exogenous signal molecule DKPs has a significant effect on the spoilage ability of spoilage bacteria,while the spore bacteriocin has a significant inhibitory effect on the susceptibility of the signal molecule DKPs.