The Phase-Dependent Regulation of Lux-Type Genes on the Spoilage Characteristics of .

, a specific spoilage microorganism, has a strong capacity to destroy food protein and lead to spoilage. The aim of this study was to evaluate the phase-dependent regulation of lux-type genes on the spoilage characteristics of H4. The auto-inducer synthase gene and a regulatory gene of the quorum sensing systems in H4 were knocked out to construct the mutant phenotypes. On this basis, the research found that the and genes had a strong positive influence on not only flagella-dependent swimming ability and biofilm formation but also the production of putrescine and cadaverine. The gene could downregulate putrescine production. The maximum accumulation of putrescine in wild type, Δ, Δ and Δ were detected at 24 h, reaching up to 695.23 mg/L, 683.02 mg/L, 776.30 mg/L and 724.12 mg/L, respectively. However, the and genes have a potential positive impact on the production of cadaverine. The maximum concentration of cadaverine produced by wild type, Δ, Δ and Δ were 252.7 mg/L, 194.5 mg/L, 175.1 mg/L and 154.2 mg/L at 72 h. Moreover, the self-organizing map analysis revealed the phase-dependent effects of two genes on spoilage properties. The gene played a major role in the lag phase, while the gene mainly acted in the exponential and stationary phases. Therefore, the paper provides valuable insights into the spoilage mechanisms of H4.