The Application Of New Antibacterial Agents On Mussels' Microorganism Control

To seek for new antibacterial agents, studying on their bacteriostatic effect and the application in aquatic products preservation, this paper researched the bacteriostatic effect of CP251 and CP252, compared with DTPA, meanwhile applied them in the mussels'preservation.Firstly the optimum method of MIDI Sherlock system was ensured. Then using this method combined with traditional physiological and biochemical tests was used to identify the dominanting bacteria in mussels. Later, Staphyloccocus aureus, Pseudomonas aeruginosa and Bacillus subtilis were chosed to to detect the bacteriostatic effect of CP251 and CP252, also compared with DTPA. At last a MTT experiment was needed to detect whether the new antibacterial angents were safe.The results of MIDI Sherlock system indicated that the dominanting bacteria in mussels mainly were Bacillus and Vibrio, and when the harvesting controlled at 10~0mg to 120mg and using the TSBA medium, the similarity index of the MIDI system is far bigger than 0.5, which was recommended by this system, reached to 0.802~0.805. The result of bacteriostatic experiment demonstrated that the effect of DTPA and CP251 on Staphyloccocus aureus and Pseudomonas aeruginosa is obviously better than CP252. When the concentration of CP251 is 450ppm and 10~0ppm, it could essentially inhibite the growth of Staphyloccocus aureus and Pseudomonas aeruginosa. When to Bacillus subtilis, the effect of DTPA is far beyond of CP251 and CP252. The concentration of bacterium droped from 4.5×10~7 cfu/mL to 1.4×10~3 cfu/mL at DTPA 1500ppm; while the CP251 and CP252 showed their inhibitory effect only at 3000ppm. Doing MTT experiment on these three antibacterial agents showed that the average relative inhibitory rates are: DTPA 6.75%, CP251 3.05%, CP252 7.90%, this demonstrated that these three antibacterial agents are safe at cell level. Applied to mussel preservation, the results showed that the effect of DTPA is the best, it cutted down the total viable count from 9.4×10~4 cfu/mL to 2.9×10~4 cfu/mL; the CP251 decreased it to 4.8×10~4 cfu/mL while the CP252 performed the worst.