Evaluation of Structural Changes and Molecular Mechanism Induced by High Hydrostatic Pressure in .

The contamination of infant milk and powder with poses a risk to human health and frequently caused recalls of affected products. This study aims to explore the inactivation mechanism of induced by high hydrostatic pressure (HHP), which, unlike conventional heat treatment, is a nonthermal technique for pasteurization and sterilization of dairy food without deleterious effects. The mortality of under minimum reaction conditions (50 MPa) was 1.42%, which was increased to 33.12% under significant reaction conditions (400 MPa). Scanning electron microscopy (SEM) and fluorescent staining results showed that 400 MPa led to a loss of physical integrity of cell membranes as manifested by more intracellular leakage of nucleic acid, intracellular protein and K. Real-time quantitative PCR (RT-qPCR) analysis presents a downregulation of three functional genes (, and ), which were involved in cell membrane formation, indicating a lower level of glycerol utilization, outer membrane protein assembly, and environmental tolerance. In addition, the exposure of to HHP modified oxidative stress, as reflected by the high activity of catalase and super oxide dismutase. The HHP treatment lowered down the gene expression of flagellar proteins (, and ) and inhibited biofilm formation. These results determined the association of genotype to phenotype in induced by HHP, which was used for the control of food-borne pathogens.