低温是保障水产品质量安全的重要方法，但仍有部分耐冷菌能适应低温环境，继续生长繁殖并最终导致水产品腐败变质。项目以水产品中典型的耐冷腐败微生物腐败希瓦氏菌（Shewanella putrefaciens）为研究对象，从细胞膜脂肪酸代谢角度解析其适冷机制。通过比较不同温度下腐败希瓦氏菌细胞膜微观结构、流动性、脂肪酸组分的变化，分析S. putrefaciens能够适应低温的细胞膜脂肪酸代谢的功能特异性，结合细胞蛋白质组差异表达，解析温度敏感因子和脂肪酸代谢途径；通过研究低温下S. putrefaciens去饱和酶关键基因的转录量以及转录因子含量变化，揭示“温度-不饱和脂肪酸产物-关键酶-调控因子”之间的关系，探讨S. putrefaciens在适冷过程中的分子调控机制。研究不仅将揭示S. putrefaciens的适冷机制，还将为抑制冷链中该菌生长、保障水产品低温流通中的质量安全提供理论依据。

Low temperature is widely applied to maintain the quality and safety of aquatic products, however, some kinds of psychrotrophs which are able to survive and grow at low temperature can cause spoilage of aquatic products during storage and transportation. Shewanella putrefaciens will be studied in this program, as it is one of the typical spoilage psychrotrophs in aquatic products. Through the modern technologies, the microstructure, fluidity and the compositions of fatty acids of the cell membrane will be determined to confirm the specific function of fatty acids metabolism of S. putrefaciens when it accommodates to low temperatures. We also ascertain the temperature sensing factors and the fatty acids pathway based on the differential expression of the proteomes and the previous study mentioned above. The relationship between temperature, unsaturated fatty acids, key enzymes and regulatory factors will be also analyzed by determining the transcription level of fatty acid desaturases genes and the contents of their transcription factors. The investigation about the molecular regulatory mechanisms of S. putrefaciens in cold-adaptive process is not only of importance to reveal the cold-adaptive mechanisms of S. putrefaciens, but also of great help to improve the effectiveness of cold chain transportation on the inhibition of the growth of S. putrefaciens and maintain the freshness and safety of the aquatic products.