诺邓火腿加工过程中细菌群落的动态变化

Bacterial Dynamics During the Processing of Nuodeng Dry-cured Ham

为研究诺邓火腿内部细菌的群落组成及动态变化,本文利用高通量测序技术对诺邓火腿腌制期、风干期、发酵期和成熟期4个加工阶段的细菌16S rRNA V3-V4区进行扩增和测序,并对其群落结构多样性及其与火腿理化性质的关联性进行分析。结果表明,腌制期诺邓火腿细菌多样性最高;厚壁菌门、变形菌门、放线菌门、拟杆菌门等细菌为发酵过程中优势菌群;葡萄球菌属、嗜冷杆菌属及假单胞菌属等在4个加工阶段均有分布;整个加工过程中丰度占比最高的为葡萄球菌属。含水量对腌制期细菌群落影响最大,成熟期含水量下降至33.4%左右;含盐量对风干期和发酵期样本影响最明显,在这两个时期丰度占比最高的葡萄球菌属与含盐量显著正相关,成熟期含盐量增加至约6.7%;酸碱度及游离氨基酸含量与成熟期样本关联度最大,这个时期的酸碱度为6.05左右,游离氨基酸达1.86%。通过以上研究将为理解诺邓火腿特殊品质的微生物影响机制,开发能够改善肉制品品质、提高发酵效率的发酵剂提供参考。

To study the community composition and dynamics of bacteria in Nuodeng dry-cured ham,16S rRNA gene V 3-V 4 region of interior bacteria of the ham during the curing,drying,fermentation,and maturation stages were amplified and sequenced via high-throughput sequencing technology.The diversity of bacterial community and its correlation with the physicochemical properties of ham have been analyzed.The results showed that there was the highest bacterial diversity in the ham at the curing stage.Firmicutes,Proteobacteria,Actinobacteria,Bacteroidetes and other bacteria were the dominant bacteria in the whole fermentation process.Staphylococcus,Psychrobacter,Pseudomonas and other bacteria were distributed in the four processing stages.The highest abundance in the entire processing was Staphylococcus.Moisture content had the greatest impact on the bacterial community during the curing stage,and the moisture content in the maturation stage dropped to about 33.4%.The salt content had the most obvious effect on the samples of the drying and fermentation stages in which Staphylococcus and the salt content was significantly positively correlated,and the salt content in the maturation stages increased to about 6.7%.The pH and free amino acid content were the most correlated with the samples of the maturation stages.The pH in this stage was about 6.05,and the free amino acid content reached to 1.86%.This research provided reference data for the study of microbial influence on the characteristic properties of Nuodeng ham and the development of starter culture that can improve the quality and fermentation efficiency of fermented meat products.