Inactivation of Bacillus cereus by Na-chlorophyllin-based photosensitization on the surface of packaging

• Published in: Journal of applied microbiology 2010-11, Vol.109 (5), p.1540-1548
• Main Authors: Luksiene, Z, Buchovec, I, Paskeviciute, E
• Format: Article
• Language: English
• Subjects: Anti-Infective Agents - pharmacology; Bacillus cereus; Bacillus cereus - drug effects; Bacillus cereus - radiation effects; Biological and medical sciences; Chlorophyllides - pharmacology; Decontamination - methods; decontamination technology; Food Handling - methods; Fundamental and applied biological sciences. Psychology; Light; Microbial Viability; Microbiology; Na-chlorophyllin; photosensitivity disorders; photosensitization; Product Packaging; surface
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2010.04780.x

This study was focused on the possibility to inactivate food-borne pathogen Bacillus cereus by Na-chlorophyllin (Na-Chl)-based photosensitization in vitro and after attachment to the surface of packaging material. Bacillus cereus in vitro or attached to the packaging was incubated with Na-Chl (7·5 x 10⁻⁸ to 7·5 x 10⁻⁵ mol l⁻¹) for 2-60 min in phosphate buffer saline. Photosensitization was performed by illuminating cells under a light with a λ of 400 nm and an energy density of 20 mW cm⁻². The illumination time varied 0-5 min and subsequently the total energy dose was 0-6 J cm⁻². The results show that B. cereus vegetative cells in vitro or attached to the surface of packaging after incubation with 7·5 x 10⁻⁷ mol l⁻¹ Na-Chl and following illumination were inactivated by 7 log. The photoinactivation of B. cereus spores in vitro by 4 log required higher (7·5 x 10⁻⁶ mol l⁻¹) Na-Chl concentration. Decontamination of packaging material from attached spores by photosensitization reached 5 log at 7·5 x 10⁻⁵ mol l⁻¹ Na-Chl concentration. Comparative analysis of different packaging decontamination treatments indicates that washing with water can diminish pathogen population on the surface by