Study On Formation And Control Technology Of Pseudomonas Aeruginosa Biofilm

Pseudomonas aeruginosa is an important food-borne pathogenic bacteria,which is increasing food pollution,and the detection rate in packaged drinking water is increasing year by year.It is easy to cause respiratory tract infections,urinary tract infections,sepsis,etc.,which seriously affects humans Safety of life.The main reason for Pseudomonas aeruginosa to cause food contamination is the formation of biofilms.Therefore,it is of great practical significance to study the formation rules and removal mechanisms of biofilms.This paper mainly studies the formation of Pseudomonas aeruginosa biofilm,the influence of quorum sensing system on the formation of biofilm,and the removal effect and mechanism of electrolyzed water.The main conclusions are as follows:1.The formation of Pseudomonas aeruginosa biofilm was investigated,and the following results were obtained: Crystal violet staining,silver staining,and scanning electron microscopy were used to observe the biofilms cultured for 24 h,72 h,and 120 h.Significant biofilm formation;plate counting method and determination of extracellular polymer were used to quantitatively analyze biofilms cultured for 24 h,48 h,72 h,96 h,120 h and 144 h to determine the law of biofilm formation.Through qualitative and quantitative experimental analysis of the biofilm,the results show that Pseudomonas aeruginosa is in the logarithmic phase when cultured for 24 h to 72 h,and enters the stable phase at 120 h,forming a mature biofilm,the concentration of extracellular polymer and There were significant differences in the number of colonies(P<0.05).2.A preliminary study on the influence of the quorum sensing system in regulating the formation of Pseudomonas aeruginosa biofilm,and the following results were obtained:Observe by measuring the biofilm,bacterial suspension concentration and2-heptyl-3-hydroxy-4-quinolone signal molecule It was found that with the increase of the concentration of the bacterial suspension,the concentration of signal molecules gradually increased,and the number of biofilms showed a rapid upward trend.When the concentration of signal molecules decreased,the formation of biofilms was slow and stabilized;after 9 hours of cultivation,the signal molecules The concentration reaches the maximum value,and the concentration of the bacterial suspension reaches the maximum value after 12 hours of culture.It is speculated that the concentration of signal molecules will not be secreted indefinitely.Pseudomonas aeruginosa will regulate the synthesis of signal molecules through various means to better control the signal molecule.Biological function to adapt to changes in the external environment.From the above results,it can be seen that the quorum sensing system has a regulatory effect on the formation of biofilms.3.The removal effect of electrolyzed water on the biofilm of Pseudomonas aeruginosa was investigated,and the removal mechanism was explored.The main results were as follows: Observed by scanning electron microscope,the structure of the biofilm was destroyed,and the morphology of the bacteria was also affected to varying degrees.Damage;the sterilization rates in the biofilm of each experimental group were 92.2%,33.1%,85%,and 94.4%.From the above results,it can be seen that the four groups of experiments have a certain bactericidal effect on the bacteria in the biofilm.It is considered that the acid electrolyzed water sheet It can be used in combination with alkali-acid electrolyzed water as an effective method to remove biofilm.Through the determination of extracellular polymeric substances,extracellular proteins,extracellular polysaccharides and extracellular DNA were reduced to varying degrees.The removal rates of extracellular polymeric substances were 66.6%,74.7%and 69.8% in the acidic electrolyzed water treatment group;the removal rates of extracellular polymeric substances were 28%,21.5%,and 36.5% in the alkaline electrolyzed water treatment group;the removal rates of extracellular polymeric substances were 64%,73%,and 62.3% in the acid-alkali electrolysis water treatment group;in the alkali-acid electrolysis water treatment group,the removal rate of extracellular polymeric substances was 70.8%,77.7%,and 70.5%.There were significant differences in the removal rate of extracellular polymeric substances in each experimental group(P<0.05).From the above results,it can be seen that with the increase in the removal rate of extracellular polymeric substances in each experimental group,the sterilization rate in the biofilm is on the rise,and the structure of the biofilm is less obvious.It can be seen that the removal mechanism of the electrolytic water on the biofilm is by destroying the extracellular.The polymer exposes the bacteria,better combines with the fungicide,achieves the purpose of sterilization,and has a good cleaning effect.