Also re-posting earlier post about anti-viral studies and 405nm blue light.
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similar articles about anti-fungal properties of same 405nm blue light
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5512304/What is not widely known, however, is whether aBLT can also be used to kill fungal species. We recently showed that the eukaryotic dimorphic yeast,Candida albicans, could be eradicated (∼6-log10of killing) by 70 J/cm2of 415 nm light under conditions in which human keratinocytes were hardly affectedOur findings are reinforced by the studies of other groups. It was documented by other laboratories that aBL successfully inactivatedC. albicansplanktonic cells and biofilms. In a study carried out by Gupta et al., 4.52-log10inactivation ofC. albicansin suspension was observed when 332.1 J/cm2aBL at 405 nm had been delivered.2Rosa et al. reported that 2.3-log10inactivation ofC. albicansin biofilms was observed after being exposed to 45.16 J/cm2aBL at 455 nm.3In addition toC. albicans, aBLT has also demonstrated its efficacy against other fungal species, including dermatophytes, yeasts, and molds. For example, Moorhead et al. investigated the use of aBL for inhibiting the growth ofTrichophyton rubrum,Trichophyton Mentagrophytes, andAspergillus niger.4On agar plates, the growth of the microconidia ofT. rubrumandT. mentagrophyteswas completely inhibited after an exposure of 504 J/cm2aBL at 405 nm.A. nigerconidia showed greater resistance, and colony growth developed after aBL exposure. In suspension, an exposure of 360 J/cm2resulted in complete inactivation ofT. rubrummicroconidia, whereasA. nigershowed greater resistance. After an exposure of 1440 J/cm2, however,A. nigerhyphae were completely inactivated, while only a 3-log10reduction in a conidial suspension (initially 5-log10CFU) was achieved.
In another study, 405-nm light was successfully applied for the inactivation ofSaccharomyces cerevisiaeand dormant or germinating conidia ofA.niger.5To achieve 5-log10CFU/mL reduction in a fungal suspension, the required aBL exposure was 288 J/cm2forS. cerevisiae, but a much higher value of 2.3 kJ/cm2was required for dormant conidia ofA. niger. Upon germination, the susceptibility ofA. nigerconidia to aBL significantly increased. The study also revealed that aBL inactivation of fungi involved an oxygen-dependent mechanism, as previously described in bacteria, and as is consistent with a photodynamic effect occurring.
Another application of aBL being explored is to treat postharvest spoilage in agricultural crops. It was found that aBL (410–540 nm) suppressed the growth of the blue mold (Penicillium italicum), green mold (Penicillium digitatum), gray mold (Botrytis cinerea), and stem end rot (Phomopsis citri), and significantly reduced postharvest spoilage. In addition, aBL was found to reduce the cell wall digestive enzyme activity ofP.digitatum, and could also induce octanal production in citrus fruits, which is lethal to molds. aBL also increased the scoparone concentration and ethylene production in citrus fruits, which mediate resistance to mold infection.
In conclusion, it can be seen that contrary to some beliefs, fungal cells are indeed killed by the action of blue light alone, and this effect may have both medical and agricultural applications.
https://www.nature.com/articles/s41598-017-05000-0
Recent data indicate that high-intensity blue light effectively removes bacteria from surfaces, but its efficacy against fungi has not been fully tested. Here we test a wide range of fungi that are pathogenic to humans and demonstrate that blue light is effective against some, but not all, fungal species.
https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=2101&context=usdaarsfacpub
Significance and Impact of Study: Light from two arrays of different blue LEDs significantly reduced
bacterial (Leuconostoc mesenteroides, Bacillus atrophaeus and Pseudomonas aeruginosa) viabilities. Significant in vitro viability loss was observed for the filamentous fungi, Penicillium digitatum and Fusarium graminearum when exposed to pure blue light only plus a photosensitizer. F. graminearum viability
was significantly reduced by blue light alone. Results suggest that (i) the amount of significant loss in
bacterial viability observed for blue light that is pure or with traces of other wavelengths is genus
dependent and (ii) depending on fungal genera, pure blue light is fungicidal with or without a photosensitizer
https://sfamjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/lam.12330
Significance and Impact of the Study: Grey mould (Botrytis cinerea) is a very successful necrotroph, causing serious losses in more than 200 crop hosts. This study investigated the antifungal effect of 405-nm
light on this pathogen. Our results suggest that the excitation of endogenous porphyrins and subsequent accumulation of singlet oxygen contribute to the 405-nm light-mediated photoinactivation of
grey mould. The development of symptoms in detached tomato leaves inoculated with B. cinerea spores
was significantly inhibited by irradiation with 405-nm light, indicating that this wavelength of light has
a potential use in controlling plant diseases caused by B. cinerea.
https://www.researchgate.net/publication/263892858_405_nm_light_technology_for_the_inactivation_of_pathogens_and_its_potential_role_for_environmental_disinfection_and_infection_control
Findings A large body of scientific evidence is now available that provides underpinning knowledge of the 405 nm light-induced photodynamic inactivation process involved in the destruction of a wide range of prokaryotic and eukaryotic microbial species, including resistant forms such as bacterial and fungal spores. For practical application, a high-intensity narrow-spectrum light environmental disinfection system (HINS-light EDS) has been developed and tested in hospital isolation rooms. The trial results have demonstrated that this 405 nm light system can provide continuous disinfection of air and exposed surfaces in occupied areas of the hospital, thereby substantially enhancing standard cleaning and infection control procedures. Conclusion Violet–blue light, particularly 405 nm light, has significant antimicrobial properties against a wide range of bacterial and fungal pathogens and, although germicidal efficacy is lower than UV light, this limitation is offset by its facility for safe, continuous use in occupied environments. Promising results on disinfection efficacy have been obtained in hospital trials but the full impact of this technology on reduction of healthcare-associated infection has yet to be determined.
DYOR and all that......
