The Influence of Microwave Sterilization on the Ultrastructure, Permeability of Cell Membrane and Expression of Proteins of Bacillus Cereus

Abstract

Bacillus cereus was isolated from ready-to-serve brine goose, identified by 16S rRNA gene sequencing analysis and treated with a commercial microwave sterilization condition (a power of 1,800 W at 85°C for 5 min). The influence of microwaves on the morphology, the permeability of membrane and the expression of total bacterial proteins was observed. Microwave induced the clean of bacterial nuclear chromatin, increased the permeability and disrupted the integrity of membrane. Twenty-three proteins including 18 expressed down-regulated proteins and 5 expressed up-regulated proteins were identified by HPLC-MS/MS in the samples treated with microwave. The frequencies of proteins changed after microwaves treatment were labeled as 39.13% (synthesis and metabolism of amino acid or proteins), 21.74% (carbohydrate metabolism), 8.70% (anti-oxidant and acetyl Co-A synthesis), and 4.35% (the catalyst of catabolism of bacterial acetoin, ethanol metabolism, glyoxylate pathway, butyrate synthesis and detoxification activity), respectively. This study indicates that microwaves result in the inactivation of Bacillus cereus by cleaning nuclear chromatin, disrupting cell membrane and disordering the expression of proteins.

Effects of microwave and water bath heating on the interactions between myofibrillar protein from beef and ketone flavour compounds

“…During thermal processing, the structure of beef myofibrillar protein is linked to flavour compounds, directly affecting the perception of flavours, which is particularly important for consumers in demanding high‐quality food products (Wang & Arntfield, ). Microwaving is a popular thermal process for meat due to its high heating efficiency, low energy consumption, food safety and convenience (Cao et al ., ). Microwave heating can influence the structural properties of beef myofibrillar protein as certain amino acids are very sensitive to temperature and electromagnetic field (Cai et al ., ).…”

Proteomic response and molecular regulatory mechanisms of Bacillus cereus spores under ultrasound treatment

“…Unfortunately, spore-forming bacteria are ubiquitous and can be commonly found in foods, water, environment even in the soil. Bacillus cereus ( B. cereus ) are Gram-positive, rod-shaped, aerobic spore-forming bacteria and responsible for food spoilage of various foods [4] . B. cereus greatly impact on food safety and quality due to their spoilage-causing capabilities and disease-causing potential [5] .…”

“…B. cereus greatly impact on food safety and quality due to their spoilage-causing capabilities and disease-causing potential [5] . The production of heat labile enter toxins begins once the B. cereus grow which is associated with food-borne illnesses: nausea and vomiting; abdominal cramps and diarrhea [4] . B. cereus can survive in a wide range of temperatures, pH values, water activities, even in industrial pasteurization.…”

Microwave- and heat-based decontamination of N95 filtering facepiece respirators: a systematic review

“…For example, not all institutions have access to large UV lamps, and chemical disinfection may cause significant damage to FFRs or leave hazardous residues [ 19 , 20 ]. Microwaves and heat are known to inactivate viruses and bacteria [ [21] , [22] , [23] , [24] , [25] ], including coronaviruses [ 26 , 27 ], and can be accessible and affordable [ 28 ]; however, heat and humidity may impact the electrostatic charges that confer the high filtration efficiency of the polypropylene filter in N95 FFRs [ [29] , [30] , [31] ].…”