冷藏条件下养殖大黄鱼Shewanella baltica介导的生物胺形成消长分子机制研究

Being the major causes of aquatic product such as large yellow croaker deterioration during storage, processing and circulation, spoilage bacteria and the biogenic amine they produced have been the research focus of current aquatic product storage and preservation field. It has been reported that the specific spoilage organism causing large yellow croaker deterioration is Shewanella baltica, whose spoilage activity is positively correlated with biogenic amine content significantly, and the spoilage process is regulated by bacterial quorum sensing (QS) system. Therefore, based on our previous results, this study will establish the dynamic variation rule and prediction model of biogenic amine content in cultured large yellow croaker refrigeration, explore the mechanism of biogenic amine generation and accumulation in terms of Shewanella spp. amino acid metabolic pathways, reveal the relationship between nitrogen metabolism enzyme modification, QS signaling molecules and biogenic amine generation, and finally clarify the metabolic network and molecular regulation mechanisms between Shewanella spp., biogenic amine and signaling molecules. This study focuses on the key common scientific questions of aquatic product corruption, which will further enrich the academic theory of aquatic product storage and preservation, and has important scientific significance in improving cultured fish processing quality and edible safety.

腐败菌及其产生的外源性生物胺是大黄鱼等水产品在贮藏、加工和流通过程中品质劣变的重要原因，成为目前水产食品贮藏与保鲜领域的研究热点。研究表明，引起养殖大黄鱼品质下降的特定腐败菌是希瓦氏菌（Shewanella baltica, S. baltica），其致腐性与生物胺含量具有显著的正相关，且整个腐败过程受到群体感应（Quorum sensing, QS）信号分子的调控。鉴于此，结合前期研究基础，本研究通过有效建立养殖大黄鱼冷藏条件下生物胺动态变化规律及预测模型，从希瓦氏菌介导的氨基酸代谢途径角度深入探究生物胺形成与积累的机制，揭示氮代谢酶蛋白修饰以及QS信号分子与生物胺形成的关联，最终阐明腐败希瓦氏菌-生物胺-信号分子之间的代谢网络与分子调控机制。本研究针对水产品腐败共性关键基础科学问题展开，有助于进一步丰富水产食品贮藏与保鲜学术理论，对提高养殖鱼类加工品质和食用安全性均具有重要的科学意义。

腐败菌及其产生的外源性生物胺是大黄鱼等水产品在贮藏、加工和流通过程中品质劣变的重要原因，成为目前水产食品贮藏与保鲜领域的研究热点。研究表明，引起养殖大黄鱼品质下降的特定腐败菌是希瓦氏菌（Shewanella baltica, S. baltica），其致腐性与生物胺含量具有显著的正相关，且整个腐败过程受到群体感应（Quorum sensing, QS）信号分子的调控。鉴于此，结合前期研究基础，本研究通过有效建立养殖大黄鱼冷藏条件下生物胺动态变化规律，建立了以腐胺和尸胺为指标的大黄鱼新鲜度预测模型；通过构建生物胺代谢相关基因缺失株，阐明了生物胺代谢关键基因potE和speF对生物胺形成与积累的调控作用；通过构建乙酰转移酶（KAT）及去乙酰化酶（KDAC）缺失株，探明了赖氨酸氨酸乙酰化修饰在S. baltica的生物胺形成中的调控作用；通过构建群体感应受体蛋白缺失株，揭示了群体感应系统DKP-LuxR对生物胺形成的调控作用。本研究针对水产品腐败共性关键基础科学问题展开，有助于进一步丰富水产食品贮藏与保鲜学术理论，对提高养殖鱼类加工品质和食用安全性均具有重要的科学意义。