Applications of Genomics, Metabolomics, Fourier Transform Infrared in the Evaluation of Spoilage Targets of <i>Shewanella putrefaciens</i> from Spoiled Bigeye Tuna

Abstract

<i>Shewanella putrefaciens</i> is a typical spoiler that is commonly found in seafood and has high spoilage potential. However, the spoilage mechanism against <i>Shewanella putrefaciens</i> at the gene and metabolism levels has not been well elucidated. This work determined the spoilage targets on <i>Shewanella putrefaciens</i> XY07 from spoiled bigeye tuna by genome sequencing, metabolomics, and Fourier transform infrared (FTIR) analysis. <i>Shewanella putrefaciens</i> XY07 contained some genes on spoilage regulating of <i>cys</i> genes, <i>his</i> genes, <i>spe</i> genes and <i>rpoS</i> gene involved in sulfur metabolism, histidine metabolism, arginine and proline degradation, and biofilm formation at the genome level, respectively. Some spoilage genes like <i>speC, cysM, trxB</i> genes were identified. In addition, ABC transporters, arginine and proline metabolism; beta-alanine metabolism; glycine, serine, and threonine metabolism; histidine metabolism; sulfur metabolism; and lipid metabolism were identified as important pathways related to aquatic food during spoilage, which indicated the functions of amino acid degradation in <i>S. putrefaciens</i> XY 07 by metabolomics analysis. The metabolites of l-ornithine, 5-aminopentanoate, and 4-aminobutyraldehyde could be further metabolized to spermidine and spermine, producing a spoilage odor, and were involved in arginine and proline metabolism serving as key spoilage regulating metabolisms. Therefore, <i>Shewanella putrefaciens</i> XY07 was applied to genomics, metabolomics analysis, and FTIR to provide comprehensive insight into the investigation of spoilage targets.