College of Food Science & Technology, Shanghai Ocean University, Shanghai, China; National Experimental Teaching Demonstration Center for Food Science and Engineering, Shanghai Ocean University, Shanghai, China.
College of Food Science & Technology, Shanghai Ocean University, Shanghai, China; Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai Ocean University, Shanghai, China; National Experimental Teaching Demonstration Center for Food Science and Engineering, Shanghai Ocean University, Shanghai, China; Shanghai Engineering Research Center of Aquatic Product Processing & Preservation, Shanghai Ocean University, Shanghai, China.
Food Res Int. 2022 Jul;157:111466. doi: 10.1016/j.foodres.2022.111466. Epub 2022 Jun 6.
Shewanella putrefaciens is an important spoilage bacteria in seafood and its ability to form biofilms in food processing environments increases the chances of food spoilage. Exploring the regulatory factors associated with biofilm formation and spoilage activity in S. putrefaciens is of great significance for extending the shelf life of seafood. In this work, the regulatory function of HD-GYP domain protein K2227_17660 in spoilage microorganism S. putrefaciens YZ08 was studied. The deletion mutant Δ17660 was developed to explore the effects of K2227_17660 in c-di-GMP content regulation, motility, biofilm formation, extracellular protease activity, and spoilage potential by phenotypic and transcriptional comparison with wild-type (WT) strain. Deletion of K2227_17660 significantly increased c-di-GMP content, biofilm biomass, the production of extracellular polysaccharide, trimethylamine (TMA), and putrescine compared with WT strains, and also affected membrane fatty acid composition. Furthermore, RT-qPCR results revealed the expression levels of genes associated with biofilm biomass, spoilage and unsaturated fatty acids (UFAs) synthesis changed in a manner consistent with the phenotypes. Our results indicated that K2227_17660 possesses phosphodiesterase (PDE) activity that controls the biofilm biomass and spoilage potential of S. putrefaciens. This study provided a basis for a correlation between c-di-GMP and food spoilage in S. putrefaciens, providing new insights into the control of food quality and safety.
腐败希瓦氏菌是海鲜中的一种重要腐败菌，其在食品加工环境中形成生物膜的能力增加了食物腐败的机会。探索与腐败希瓦氏菌生物膜形成和腐败活性相关的调节因子对于延长海鲜的保质期具有重要意义。在这项工作中，研究了 HD-GYP 结构域蛋白 K2227_17660 在腐败微生物 S. putrefaciens YZ08 中的调节功能。通过与野生型（WT）菌株的表型和转录比较，开发了缺失突变体Δ17660，以探索 K2227_17660 在 c-di-GMP 含量调节、运动性、生物膜形成、胞外蛋白酶活性和腐败潜力方面的作用。与 WT 菌株相比，K2227_17660 的缺失显著增加了 c-di-GMP 含量、生物膜生物量、胞外多糖、三甲胺（TMA）和腐胺的产生，并影响了膜脂肪酸组成。此外，RT-qPCR 结果显示，与生物膜生物量、腐败和不饱和脂肪酸（UFAs）合成相关的基因表达水平的变化与表型一致。我们的结果表明，K2227_17660 具有磷酸二酯酶（PDE）活性，可控制腐败希瓦氏菌的生物膜生物量和腐败潜力。这项研究为腐败希瓦氏菌中 c-di-GMP 与食物腐败之间的相关性提供了依据，为控制食物质量和安全提供了新的见解。
