Abstract:This project used commercially available frozen chicken leg, frozen chicken wing and frozen chicken feet as the research objects to evaluate the microbial contamination in frozen chicken meat and analyze the diversity of cold-resistant bacteria distribution. The results showed that the microbial contamination of frozen chicken feet was the most serious (up to 105 CFU/g). A total of 100 cold-tolerant bacteria were isolated from three types of chicken meat samples, of which Pseudomonas accounted for 49%, Psychrobacter and Serratia accounted for 13% and 12%, respectively. In the genus Pseudomonas, sixty-one percent of Pseudomonas were identified as Pseudomonas fragi. A phylogenetic tree was built for the 30 strains isolated from frozen chicken feet to estimate their phylogenetic positions. A P. fragi 30-1 strain was further selected to study its growth characteristics and subjected to the antibacterial test. The results showed that P. fragi 30-1 had strong cold resistance, could withstand a maximum of 2.5% NaCl, and is suitable for growth in a pH 6~8 environment. Chloramphenicol, roxithromycin, and tea polyphenols had good antibacterial activities against P. fragi 30-1, and the minimum inhibitory concentrations (MICs) were 0.31 mg/mL, 0.62 mg/mL and 0.62 mg/mL, respectively. This study provided a basis for understanding the safety of frozen chicken and also insights into the control of P. fragi contamination.
