鲐鱼和大黄鱼冷藏期间体表细菌群落组成和代谢功能的比较分析

为研究鲐鱼和大黄鱼冷藏期间体表细菌群落和代谢功能的差异，采用Illumina MiSeq测序技术和PICRUSt工具对鲐鱼和大黄鱼冷藏期间体表细菌群落和代谢功能进行比较分析。结果表明：鲐鱼体表细菌群落的丰富度随冷藏时间的延长而增加，多样性却下降；大黄鱼体表细菌群落的丰富度和多样性变化均不显著。嗜冷杆菌属（Psychrobacter）和希瓦氏菌属（Shewanella）分别是鲐鱼和大黄鱼体表的优势菌，且其相对丰度分别与鲐鱼（r＝0.709，P＜0.001）和大黄鱼（r＝0.600，P＝0.008）挥发性盐基氮含量显著正相关；因此，它们可能分别是鲐鱼和大黄鱼体表的特定腐败菌。鲐鱼体表细菌的蛋氨酸、酪氨酸和组氨酸等参与氨基酸代谢的相关基因的相对丰度显著高于同一冷藏时期的大黄鱼（P＜0.05），这在一定程度上从细菌代谢水平解释了鲐鱼比大黄鱼更易腐败的原因。研究结果可为不同水产品采取针对性的贮藏保鲜策略提供参考。

Comparative Analysis of Compositions and Metabolic Functions of Bacterial Communities on the Surface of Mackerel and Large Yellow Croaker during Refrigerated Storage

The aims of this study were to compare the compositions and metabolic functions of the bacterial communities on mackerel and large yellow croaker during refrigerated storage by Illumina MiSeq sequencing and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt). The results showed that the richness of bacteria on mackerel surface was increased while the bacterial diversity was decreased during prolonged storage; however, no significant change was observed for large yellow croaker. Psychrobacter and Shewanella were the dominant bacteria on mackerel and large yellow croaker, respectively, and their relative abundance was positively correlated with total volatile basic nitrogen (TVB-N) contents (r = 0.709, P < 0.001 for mackerel; r = 0.600, P = 0.008 for large yellow croaker), respectively. This may suggest that Psychrobacter is the specific spoilage organism (SSO) on mackerel, while Shewanella is the SSO on large yellow croaker. The relative abundance of genes related to the metabolism of amino acids such as methionine, tyrosine and histidine on mackerel was higher than that on large yellow croaker at the same storage period (P < 0.05). This may partially explain why mackerel is more perishable than large yellow croaker based on the metabolic levels of the bacterial communities. This study provides a basis for adopting targeted strategy to the preservation of different aquatic products.