Antiseptic Effect of Pseudomonas Bacteriophages PrH-181 on Large Yellow Croaker Meat

In order to control the spoilage of raw large yellow croaker fillets caused by Pseudomonas. The antibacterial ability of the Pseudomonas bacteriophage PrH-181 against the spoilage of large yellow croaker under aerobic refrigeration at 4℃ was studied. After treating the fish juice with different titer of 10² to 10⁸ pfu/mL, incubating for 14 h at 30℃, the results of OD_{620 nm}showed the bacteriophage PrH-181 exhibited significant(P<0.05) antibacterial activity, when its titer was greater than 10³ pfu/mL.From the change of colony numbers, pH and TVB-N concentration which characterize the extent of spoilage, as for the control, there were 10⁶ cfu/g Pseudomonas, which was the critical value as symbolic of spoilage beginning, in the fourth day, and the minimun pH occurred in the second day, and the TVB-N concentration exceeded the critical value 30 mg/100 g on the fourth day. As for 10⁴ pfu/mL and 10⁶ pfu/mL phage-treated group, the time for the critical value of colony numbers occurred on the 10th and 12th day, and minimum pH occurred on the 8th and 12th day, TVB-N concentration was up to the critical value on the 12th and 14th day. So, it could be inferred that the preservation effect of bacteriophage PrH-181 on the large yellow croaker was obvious, and the higher the titer was, the better the preservation effect would be.