基于PCR-DGGE分析云南牛干巴的细菌群落结构

Analysis of Bacterial Community Structure of Yunnan Dry-Cured Beef by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophorsis

以黄牛后腿肉为原料,采用传统工艺加工云南牛干巴,分别在腌制前、腌制中期、腌制后期、成熟1个月、成熟2个月与成熟3个月6个加工阶段取样,应用聚合酶链式反应-变性梯度凝胶电泳(polymerase chain reaction-denaturing gradient gel electrophorsis,PCR-DGGE)技术分析不同加工阶段牛干巴的细菌群落结构及多样性差异。结果表明:牛干巴具有较为丰富的细菌多样性,同时存在明显的优势种群结构变化。腌制阶段的细菌种类最为丰富;腌制前与腌制后的样品中细菌群落结构差异明显,同一阶段细菌群落结构组成类似;存在于牛干巴加工过程中的细菌主要为葡萄球菌属(Staphylococcus)、嗜冷杆菌(Psychrobacter)及明串珠菌属(Leuconostoc)等,其中肠膜明串珠菌葡聚糖亚种(L.mesenteroides subsp.dextranicum)是优势菌种;此外,牛干巴加工过程中还存在着不可培养(unculturable bacterium)的菌群。

Yunnan dry-cured beef was processed from beef hindquarter using the traditional method. Six samples were collected before curing, during the mid- and late-curing stages, and after one, two and three months of fermentation and ripening, respectively and then the bacterial community structure and diversity in dry-cured beef at different processing stages were analyzed using polymerase chain reaction-denaturing gradient gel electrophorsis （PCR-DGGE）. The results showed that dry-cured beef was relatively rich in bacterial diversity, and the dominant bacterial populations in it were highly diverse. The highest bacterial diversity was found during the curing process of meat; there was a significant difference in the bacterial community structure between cured and uncured meat. The bacterial community structure remained similar at the same stage of processing. The bacterial community mainly consisted of Staphylococcus, Psychrobacter and Leuconostoc, with the predominance of L.mesenteroides subsp. dextranicum, along with unculturable bacteria, during the processing of dry-cured beef.