不同储藏温度下猪皮表面细菌多样性研究

Study on bacterial diversity of pig skin surface under different storage temperatures

【目的】探究不同储藏温度下猪皮表面细菌多样性,为猪皮品质控制提供依据。【方法】将猪皮分别在4、25、37℃储藏温度下放置7 d,提取猪皮表面细菌DNA并进行高通量测序,通过多样性指数、韦恩(Venn)图、主坐标分析法(principal coordinate analysis,PCoA)、菌落组成以及热图等分析不同储藏温度下猪皮表面细菌的差异性。【结果】相同储藏时间内,不同储藏温度下猪皮表面细菌物种既有重叠也有特异性;37℃猪皮表面细菌多样性指数与4、25℃均存在显著性差异,而4、25℃之间仅丰富度估计量(Chao)指数和丰富度观测量(Sobs)指数存在显著性差异;37℃猪皮表面细菌物种数及特有物种数大于4、25℃;4、25和37℃猪皮表面细菌样本距离较远;不同储藏温度下猪皮表面细菌中嗜冷杆菌属相对丰度均较高;4℃优势菌为嗜冷杆菌属(73.2%),25℃优势菌为嗜冷杆菌属(39.5%),37℃优势菌为假单胞菌属(23.8%)和漫游球菌属(23.7%)。【结论】不同储藏温度对猪皮表面细菌群落结构和多样性影响较大,37℃猪皮表面细菌物种多样性最高。不同储藏温度下猪皮表面优势菌不同,需要采取针对性措施抑制嗜冷杆菌属以延缓猪皮产品劣变,以延长猪皮货架期。

【Objective】This study aims to explore the bacterial diversity on the surface of pig skin under different storage temperatures and provide basis for the quality control of pigskin.【Methods】The pig skin was stored at 4,25 and 37℃for 7 days.The bacterial DNA on the surface of the pig skin was extracted and sequenced with high-throughput.The diversity index,Venn diagram,principal component analysis(PCoA),colony composition,heat map and other indicators were used to analyze the diffe-rences of the pig skin surface bacteria under the different storage temperatures.【Results】The results showed that the bacterial species on pig skin surface under different storage temperatures had both overlapping and specificity during the same storage time.The bacterial diversity index of pig skin surface at 37℃was significantly different from that at 4 and 25℃,while only the Chao index and sobs index were significantly different between 4 and 25℃.The Venn diagram of three groups of samples showed that the number of bacterial species and endemic species on the surface of pig skin at 37℃was greater than that of pig skin samples at 4 and 25℃.By analyzing PCoA index,it was found that the distance between bacteria samples on the surface of pig skin at 4,25 and 37℃was far,indicating that there were differences in colony results.relative abundance of Psychrophilic bacteria on the surface of pig skin was high at different storage temperatures.The dominant bacteria at 4,25℃were Psychrophilicus(73.2%)and Psychrophilicus(39.5%),which at 37℃were Pseudomonas(23.8%)and Rhodococcus(23.7%).【Conclusion】Different storage temperatures have a great impact on the bacterial community structure and diversity on the surface of pig skin,and the bacterial species diversity on the surface of pig skin at 37℃is the highest.The dominant bacteria on the surface of pigskin are different under different storage temperatures.At the same time,targeted measures should be taken to inhibit psychrophilic bacteria in order to delay the deterioration of pigskin products and prolong the shelf life of pigskin.