Inactivation of Bacteria Using Bioactive Nanoparticles and Alternating Magnetic Fields

Design and Application of Near Infrared LED and Solenoid Magnetic Field Instrument to Inactivate Pathogenic Bacteria

PURPOSE

This study aims to evaluate the efficiency of infrared LEDs with a magnetic solenoid field in lowering the quantity of gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria, as well as the best exposure period and energy dose for inactivating these bacteria.

METHOD

Research has been performed on a photodynamic therapy technique called photodynamic inactivation (PDI), which combines infrared LED light with a wavelength range of 951-952 nm and a solenoid magnetic field with a strength of 0-6 mT. The two, taken together, can potentially harm the target structure biologically. Infrared LED light and an AC-generated solenoid magnetic field are both applied to bacteria to measure the reduction in viability. Three different treatments infrared LED, solenoid magnetic field, and an amalgam of infrared LED and solenoid magnetic field, were used in this study. A factorial statistical ANOVA analysis was utilized in this investigation.

RESULTS

The maximum bacterial production was produced by irradiating a surface for 60 min at a dosage of 0.593 J/cm², according to the data. The combined use of infrared LEDs and a magnetic field solenoid resulted in the highest percentage of fatalities for Staphylococcus aureus, which was 94.43 s. The highest percentage of inactivation for Escherichia coli occurred in the combination treatment of infrared LEDs and a magnetic field solenoid, namely, 72.47 ± 5.06%. In contrast, S. aureus occurred in the combined treatment of infrared LEDs and a magnetic field solenoid, 94.43 ± 6.63 percent.

CONCLUSION

Staphylococcus aureus and Escherichia coli germs are inactivated using infrared illumination and the best solenoid magnetic fields. This is evidenced by the rise in the proportion of bacteria that died in treatment group III, which used a magnetic solenoid field and infrared LEDs to deliver a dosage of 0.593 J/cm² over 60 min. According to the research findings, the magnetic field of the solenoid and the infrared LED field significantly impact the gram-positive bacteria S. aureus and the gram-negative bacteria E. coli.

A review of potential antibacterial activities of nisin against Listeria monocytogenes: the combined use of nisin shows more advantages than single use

Listeria monocytogenes is a foodborne pathogen causing serious public health problems. Nisin is a natural antimicrobial agent produced by Lactococcus lactis and widely used in the food industry. However, the anti-L. monocytogenes efficiency of nisin might be decreased due to natural or acquired resistance of L. monocytogenes to nisin, or complexity of the food environment. The limitation of nisin as a bacteriostatic agent in food could be improved using a combination of methods. In this review, the physiochemical characteristics, species, bioengineered mutants, and antimicrobial mechanism of nisin are reviewed. Strategies of nisin combined with other antibacterial methods, including physical, chemical, and natural substances, and nanotechnology to enhance antibacterial effect are highlighted and discussed. Additionally, the antibacterial efficiency of nisin applied in real meat, dairy, and aquatic products is evaluated and analyzed. Among the various binding treatments, the combination with natural substances is more effective than the combination with physical and chemical methods. However, the combination of nisin and nanotechnology has more potential in terms of the impact on food quality.