Electroactivity of Shewanella putrefaciens induced by shrimp matrix: Catalyst for spoilage acceleration

The bacterium Shewanella is commonly found in fishery products along the whole cold chain transportation system and poses a significant threat to public health and the global economy due to its propensity for contaminating food and causing spoilage. In this research, four specific spoilage organisms (SSO) (Shewanella spp.) isolated from various refrigerated aquatic products were found to exhibit electrochemical properties. When modifying the conventional microbial fuel cells with shrimp meat extract as the donor-acceptor, an interesting result was found in the current output of the "shrimp battery", where it exhibits a significant activation effect and the accumulation of total volatile basic nitrogen, Trimethylamine N-oxide and bioamines. The transcriptomic analysis reveals that the extracellular electron transport pathway of Shewanella putrefaciens-329 in aquatic environments underwent a transfer from Mtr cluster to cbb₃-type, with its metabolic focus transitioning toward the accumulation of amines, sulfides, and biofilms. Our findings demonstrate that the electrochemical characteristics of Shewanella in aquatic environments play a crucial role in accelerating low-temperature spoilage of aquatic products, thereby offering a novel target for mitigating the detrimental loss of aquatic products caused by Shewanella.