The aim of this study is evaluating the protein degradation capacity of specific spoilage organisms (SSOs) and in fish flesh during chilled storage and revealing the underlying genes by whole-genome sequencing (WGS). Biochemical and physical tests were performed on fish flesh inoculated with and individually, including textural properties, myofibrillar fragmentation index, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles, free amino acid composition, total volatile basic nitrogen (TVB-N), trichloroacetic acid (TCA) soluble peptides, and muscle microstructure. Results showed that and exhibited a strong capacity for decomposing the fish protein, and the deterioration of fish flesh texture was primarily attributed to . The genes from SSOs associated with the production of proteases were identified by whole genome sequencing and serine protease may be the primary enzyme secreted by SSOs involved in the degradation of fish protein. Therefore, the present study has shed light on the mechanisms of protein degradation induced by SSOs, thereby offering valuable insights for the development of effective quality control strategies.

中文翻译：

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深入了解鱼源性破坏者嗜冷假单胞菌和腐败希瓦氏菌引起的鱼类蛋白质降解：从全基因组测序到质量变化

本研究的目的是评估冷藏期间特定腐败生物（SSO）和鱼肉的蛋白质降解能力，并通过全基因组测序（WGS）揭示潜在基因。对接种的鱼肉和单独接种的鱼肉进行生化和物理测试，包括质构特性、肌原纤维断裂指数、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）谱、游离氨基酸组成、总挥发性碱性氮（TVB-N） 、三氯乙酸 (TCA) 可溶性肽和肌肉微观结构。结果表明， 和 具有很强的分解鱼蛋白的能力，鱼肉质地恶化的主要原因是 。通过全基因组测序鉴定了SSOs中与蛋白酶产生相关的基因，丝氨酸蛋白酶可能是SSOs分泌的参与鱼类蛋白质降解的主要酶。因此，本研究揭示了 SSO 诱导的蛋白质降解机制，从而为制定有效的质量控制策略提供了宝贵的见解。