Study on identification and basic characteristics of the pressure-resistant bacteria isolated in Nanjing water-boiled salted duck

The pressure-resistant bacteria in Nanjing water-boiled salted duck, and evaluate the spoilage capability, the tolerance to NaCl and growth at different temperatures of the pressure-resistant bacteria were determined. The breast of the duck was treated by 400MPa (20℃, 10min) and stored at 25℃, and the total number of colonies was used to tell the shelf-life. We used culture-dependent method to isolate the pressureresistant bacteria, which were identified by colony morphology, Gram stain, bacterial morphology and Vitek Ⅱsystem. What's more, the spoilage capability and the growth at different NaCl concentrations and different temperatures were studied. The results showed that high pressure 400MPa (20℃, 10min) treatment con effectively inhibit the bacteria in the breast and prolong its shelf life. The pressure-resistant bacteria included Staphylococcus warneri, Staphylococcus epidermidis, Enterococcus faecalis and Bacillus cereus. Among them, Bacillus cereus had potential spoilage capability, and Enterococcus faecalis had acid production capacity.These pressure-resistant bacteria could grow well at 7% NaCl concentration, and showed the strongest ability to grow at 35℃.