Carton sterilization by u.v.-C excimer laser light: recovery of Bacillus subtilis spores on vegetable extracts and food simulation matrices Carton sterilization by u.v.-C excimer laser light: recovery of Bacillus subtilis spores on vegetable extracts and food simulation matrices
Abstract
Aims: To determine the recovery of Bacillus subtilis spores loaded onto preformed cartons and irradiated with u.v.-excimer laser (248 nm) light.
Methods and Results: Bacillus subtilis spores irradiated with u.v.-excimer laser light retained phase brightness, but were blocked at various stages of germination. In the presence of germinant, the majority of spores began to lose phase brightness but only after an extended lag period (ca 90 min). After 6 h ca 9% of the spores had elongated but failed to form new cells, approx. 12% had undergone partial phase darkening (grey spores), 15% remained phase bright whilst the remainder had turned fully phase dark but failed to elongate. No enhanced recovery of u.v.-treated spores (with intact or permeabilized coats) occurred in media containing hen egg white lysozyme or vegetable extracts (celery, carrot, swede or turnip). However, recovery did occur when irradiated spores were incubated for 26 d, semiaerobically, within cartons containing nutrient broth or milk.
Conclusions: The germination ability of B. subtilis spores is altered following u.v.-excimer laser treatment. Recovery of treated spores was found in liquid systems but not on agar plates supplemented with vegetable extracts or lysozyme.
Significance and Impact of the Study: The potential recovery of u.v.-excimer laser-treated spores in a range of carton-packed food systems requires further investigation.
- Articles
- A completely laser-based production method for fibre Bragg grating devices
- A study of angular dependence in the ablation rate of polymers by nanosecond pulses
- Advanced laser micromachining processes for MEMS and optical applications
- Advanced laser tools for display device production on super large substrates
- Applications of laser ablation to microengineering
- CAD/CAM software for an industrial laser manufacturing tool
- Characterization of the effects of different lasers on the tensile strength of fibers during laser writing of fiber Bragg gratings
- Development of an industrial femtosecond laser micromachining system
- Developments in laser micro-machining techniques
- Fabrication of axisymmetric ceramic microparts using pulsed laser ablation
- Femtosecond laser micromachining: Current status and applications
- Industrial applications of pulsed lasers to materials microprocessing
- Laser micromachining for manufacturing MEMS devices
- Laser micromachining in 3D and large area applications.
- Laser micromachining of high-density optical structures on large substrates
- Laser micromachining of optical materials with a 157-nm fluorine laser
- Laser micromachining techniques for industrial MEMS applications
- Laser micromachining: new developments and applications
- Laser micromachining: new techniques and developments for display applications (Proceedings Paper)
- Microhole drilling using reshaped pulsed Gaussian laser beams
- New developments and applications in the production of 3D microstructures by laser micromachining
- New techniques for laser micromachining MEMS devices
- Pulsed laser ablation for volume micro-optical arrays on large area substrates
- Pulsed laser ablation of polymers for display applications
- Pulsed laser processing of shallow micro-optical structures
- Recent applications of pulsed lasers in advanced materials processing
- UV laser micromachining of silicon, indium phosphide and lithium niobate for telecommunications applications
- Carton sterilization by u.v.-C excimer laser light: recovery of Bacillus subtilis spores on vegetable extracts and food simulation matrices
- Diamond photodetector response to deep UV excimer laser excitation
- Direct manufacture of miniature bio-particle electro-manipulator devices using excimer laser mask projection techniques
- Excimer laser microfabrication and micromachining
- Excimer laser micromachining of polymers using half-tone masks: mask design and process optimization.
- Excimer laser micromachining system for the production of bioparticle electromanipulation devices
- Excimer laser micromachining: a 15-year perspective
- Excimer laser patterning of thick and thin films for high density packaging
- Excimer laser projector for microelectronics applications
- Fabrication techniques and their application to produce novel micromachined structures and devices using excimer laser projection
- High resolution micromachining using short wavelength and shortpulse lasers
- High-resolution 157-nm imaging for lithography and micromachining applications
- High-resolution 157-nm laser micromachining of polymers
- High-resolution microlithography using a 193-nm excimer laser source
- Inactivation of Bacillus subtilis spores on aluminum and polyethylene preformed cartons by UV-excimer laser irradiation
- Inactivation of Bacillus subtilis spores on packaging surfaces by u.v. excimer laser irradiation
- Laser-assisted manufacture for performance-optimized dielectrically loaded GPS antennas for mobile telephones
- Laser microprojection for micromechanical device fabrication
- Manufacture of a conformal multilayer rf antenna substrate using excimer mask imaging technology and a 6-axis robot
- Manufacture of miniature bioparticle electromanipulators by excimer laser ablation
- Microstructuring by excimer laser
- Modelling of solid-state and excimer laser processes for 3D micromachining.
- Multilevel diffractive optical element manufacture by excimer laser ablation and halftone masks
- Novel applications of excimer lasers for fabricating biomedical and sensor products
- Practical study of the effects of exposure conditions on the quality of fiber Bragg gratings written with excimer and argon-ion lasers
- Production of novel 3D microstructures using excimer laser mask projection techniques
