Inactivation Mechanism of Low-Energy X-Ray on Salmonella
The problem of food safety and public health caused by bacterial infection has always been a hot issue of social concern,so it is of great significance and application value to explore a safe and efficient food sterilization technology.X-ray irradiation,a new non-thermal sterilization technology with high penetrability that is safety controllable,has a high linear energy transfer(LET)value and relative biological effect(BRE).However,the mechanism for its inactivation effect on foodborne pathogenic bacteria such as Gram-negative bacteria is rarely reported,which greatly limits its application and development in the field of food microbial safety.In this study,the inactivation effect and mechanism of low-energy X-ray on Salmonella,a common foodborne Gram-negative pathogen,were investigated by transcriptomics in an effort to provide a theoretical basis for the application of low-energy X-ray in food safety control.The influence of X-ray irradiation at doses of 0,0.1,0.2,0.3,0.4,0.5 and 0.6 kGy on the survival and sublethal effect of Salmonella was analyzed using plate counting method,the effect of X-ray irradiation on bacterial ultrastructure using scanning electron microscopy(SEM)and transmission electron microscopy(TEM)was examined,and the mechanism of Salmonella inactivation by low-energy X-ray was elucidated by transcriptomic analysis.Results showed that the sub-lethal rate of Salmonella was the highest(99.44％)when exposed to 0.5 kGy of X-rays.Low energy X-ray destroyed the bacterial cell wall and membrane.The transcriptome sequencing results showed that among the 292 differentially expressed genes(DEGs)identified,214 were up-regulated and 78 were down-regulated.DEGs analysis showed that low energy X-ray irradiation could cause DNA damage and regulate oxidative stress response,amino acid synthesis,energy metabolism,virulence,and transmembrane transport in bacterial cells.These findings suggested that low-energy X-ray irradiation has the potential to inhibit bacterial growth and metabolism of cells and thereby reduce the risk of bacterial infection.
国家科技期刊平台
NSTL
万方数据
维普
