Study on inactivation mechanisms of Listeria grayi affected by pulse magnetic field via morphological structure, Ca²⁺ transmembrane transport and proteomic analysis

Abstract

Summary The inactivation mechanism of PMF on Listeria grayi (L. grayi) was investigated through the analysis of biological effects as well as the monitoring of morphology, membrane permeability and intracellular proteins of cells. Under the optimal inactivation conditions of PMF (2.5 T and 25 pulses), the analysis of transmission electron microscopy (TEM) and laser scanning confocal microscopy (LSCM) showed that PMF‐treated cells membranes were damaged, resulting in the increase in intracellular Ca2+ fluorescence intensities. A significant (P < 0.01) negative correlation between intracellular Ca2+ fluorescence intensities and the amount of colonies was found. Proteomic analysis showed that the mode‐of‐action of cells outer membrane, the stability of intracellular proteins and the metabolism‐related proteins might be affected by PMF. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that PMF treatment could affect the nitrogen, organic and energy metabolisms of L. grayi, inducing the death of cells finally.

Simulation study of cell transmembrane potential and electroporation induced by time-varying magnetic fields

“…TMFs, including PMFs and oscillating magnetic fields (OMFs), are an emerging non-thermal technique in the food processing industry [1,2,3], which can maximize the preservation of food appearance, flavour, texture, and nutritional quality, and improve the freezing process and quality of fresh ground beef [4], chicken breast [5], blueberries [6], cucumber [7], etc. In terms of bactericidal effect, PMF can be used to inhibit and destroy microorganisms such as Escherichia coli [8,9,10], yeast [11], and Staphylococcus aureus [12].…”

“…Since L. Towhidi et al [15] discovered that the PMF could induce cellular membrane damage and increase its permeability, plenty of empirical studies were commenced to unveil the mechanism of PMF-induced magnetoporation [3,14,16,17,18,19,20], and explore its possibility of applying it to medical practice and food processing. The mechanism of PMFinduced increase in the cellular membrane permeability has been always speculated to be directly related to electroporation (EP) [20,21,22].…”

Simulation study of Cell Transmembrane Potential and Electroporation Induced by Time-Varying Magnetic Fields

“…TMFs, including PMFs and oscillating magnetic fields (OMFs), are an emerging non-thermal technique in the food processing industry [1, 2, 3], which can maximize the preservation of food appearance, flavour, texture, and nutritional quality, and improve the freezing process and quality of fresh ground beef [4], chicken breast [5], blueberries [6], cucumber [7], etc. In terms of bactericidal effect, PMF can be used to inhibit and destroy microorganisms such as Escherichia coli [8, 9, 10], yeast [11], and Staphylococcus aureus [12].…”

“…Since L. Towhidi et al . [15] discovered that the PMF could induce cellular membrane damage and increase its permeability, plenty of empirical studies were commenced to unveil the mechanism of PMF-induced magnetoporation [3, 14, 16, 17, 18, 19, 20], and explore its possibility of applying it to medical practice and food processing. The mechanism of PMF-induced increase in the cellular membrane permeability has been always speculated to be directly related to electroporation (EP) [20, 21, 22].…”

Inactivation mechanisms of electron beam irradiation on Listeria innocua through the integrity of cell membrane, genomic DNA and protein structures

“…Sterilisation is one of the most effective food preservation methods for extending the shelf life of food products (Li & Farid, ). Traditional thermal sterilisation technology significantly reduces microbial populations but trigger potential damage to flavour, nutrients and vitamins (Wu et al ., ). With the development of non‐thermal technologies, ionising radiation has been regarded as an effective bactericidal technology that aims to achieve both microbiological safety and minimum loss of food nutrition and quality characteristics.…”