低温贮藏对冷鲜鸡腐败菌菌群变化的影响

Effect of Storage Temperature on Changes in Spoilage Bacterial Community in Chilled Chicken

摘要:

利用传统平板培养和变性梯度凝胶电泳（DGGE）指纹图谱相结合的方法，对冷鲜鸡低温贮藏期间的腐败菌菌群变化进行了分析。传统培养结果显示，冷鲜鸡的初始菌群主要为肠道菌、乳酸菌和葡萄球菌；4 ℃贮藏条件时微生物生长速度高于0 ℃和-1.5 ℃；贮藏6 d后，4 ℃贮藏样品的优势菌群为假单胞菌，0 ℃和-1.5 ℃贮藏下样品的优势菌群为葡萄球菌。通过变性梯度凝胶电泳法直接对冷鲜鸡中的菌群变化进行了分析，发现不动杆菌、伯克霍尔德氏菌、假单胞菌、肠杆菌，腐生葡萄球菌及乳球菌是样品中的主要污染菌；4 ℃贮藏时，假单胞菌条带逐渐变亮，0 ℃和-1.5 ℃条件下菌群的条带亮度变化不明显。本研究发现贮藏温度对样品中菌群多样性的变化影响较大，冰点温度下贮藏更利于冷鲜鸡中嗜冷菌的控制和产品的保鲜。

Abstract:

The traditional plate culture and polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) methods were used to monitor changes in the bacterial community causing spoilage of chicken at different storage temperatures. The traditional culture results showed that initial flora in chilled chicken samples consisted mainly of intestinal bacteria, lactic acid bacteria, and Staphylococcus sp.; the growth rate of microorganisms was higher in samples stored at 4 ℃ than those stored at 0 ℃ and -1.5 ℃. After six days of storage, Pseudomonas sp. was predominant in samples stored at 4 ℃, while Staphylococcus sp. was predominant in samples stored at 0 ℃ and -1.5 ℃. PCR-DGGE results showed that Acinetobacter sp., Burkholderia sp., Pseudomonas sp., Enterobacter sp., Staphylococcus saprophyticus, and Lactococcus sp. constituted major contaminants. When the sample was stored at 4 ℃, the band representing Pseudomonas sp. gradually became brighter and there was no significant change in band brightness for samples stored at 0 ℃ and -1.5 ℃. The results of this study show that storage temperature has a significant effect on bacterial diversity. Additionally, freezing temperature provides better control of psychrophiles and is more favorable for preservation of chicken products.