Pigeot-Remy S.,CNRS Research on Catalysis and Environment in Lyon |
Pigeot-Remy S.,Ahlstrom |
Pigeot-Remy S.,CNRS Laboratory for Microbiology, Adaptation & Pathogenesis |
Real P.,CNRS Research on Catalysis and Environment in Lyon |
And 7 more authors.
Applied Catalysis B: Environmental | Year: 2013
The effects of UV-A and UV-C radiation on fungal spores were investigated before and after their germination in photocatalytic and non-photocatalytic air filters commonly used in heating, ventilating, and air conditioning (HVAC) systems.Immediately after the coating of spores on filters, exposure to both types of UV radiation induced the appearance of an inactivation threshold for long durations of exposure probably resulting from the presence of Aspergillus niger spores inside the activated charcoal layer. The use of a thin photocatalytic filter without activated charcoal demonstrated a better disinfection efficiency with total inactivation of the spores, due to an optimal contact between spores and TiO2 coating.The effects of UV radiation were then assessed on spore germination for both types of filters. The inactivation of spores in illuminated photocatalytic filters resulted in an irreversible inhibition of the fungal germination under UV-A or UV-C radiation. In contrast, fungal spores were able to germinate in non-photocatalytic filters despite previous exposure to both types of UV radiation. The monitoring of ergosterol amounts, the major sterol of fungal membranes, corroborated these results.Finally, UV-A or UV-C radiation exposure of filters after spore germination had a lesser disinfection efficiency than experiments whereby spores had just been applied onto the filters, due to the absence of contact between the biological pollutants and the photocatalyst coating.Our results thus demonstrated the interest to use photocatalytic filters ensuring optimal contact between pollutants and TiO2 coating to lead to a total inactivation of fungal spores in filters of HVAC systems. © 2013 Elsevier B.V.
Vacher S.,CONIDIA |
Hernandez C.,CONIDIA |
Bartschi C.,CNRS Laboratory for Microbiology, Adaptation & Pathogenesis |
Poussereau N.,CNRS Laboratory for Microbiology, Adaptation & Pathogenesis
Building and Environment | Year: 2010
Biocide-free and biocide-treated plasterboards as well as aluminum plate as a reference material normally considered as being insensitive to mould growth have been used as substrate to check the influence of different common wall coverings, i.e. paints and wall papers, on fungal growth. The results described in this paper show that any non-biodegradable material (such as aluminum) can become a substrate to fungal infestation once painted or wall paper applied, depending on the type of paint or wall paper used. Moreover, a biodegradable material treated with a biocide (biocide-treated plasterboard) offers partial resistance to fungal growth at a biodegradable surface covering. The main conclusion of this study is that composition of the surface covering applied on building materials is as important as the substrate itself when considering the bioreceptivity of this material to potential fungal infestation. Accordingly, any discussion on the ability of a given building material to resist or not to fungal infestation must refer to the exact composition of the surface covering (paint, varnish, wall paper, etc). This has not often been the case in many of the previous studies published on the topic. © 2009 Elsevier Ltd. All rights reserved.
Cherrad S.,Bayer AG |
Girard V.,Bayer AG |
Dieryckx C.,Bayer AG |
Goncalves I.R.,Bayer AG |
And 7 more authors.
Metallomics | Year: 2012
Although essential in many cellular processes, metals become toxic when they are present in excess and constitute a global environmental hazard. To overcome this stress, fungi have evolved several mechanisms at both intracellular and extracellular levels. In particular, fungi are well known for their ability to secrete a large panel of proteins. However, their role in the adaptation of fungi to metal toxicity has not yet been investigated. To address this question, here, the fungus Botrytis cinerea was challenged to copper, zinc, nickel or cadmium stress and secreted proteins were collected and separated by 2D-PAGE. One hundred and sixteen spots whose volume varied under at least one tested condition were observed on 2D gels. Densitometric analyses revealed that the secretome signature in response to cadmium was significantly different from those obtained with the other metals. Fifty-five of these 116 spots were associated with unique proteins and functional classification revealed that the production of oxidoreductases and cell-wall degrading enzymes was modified in response to metals. Promoter analysis disclosed that PacC/Rim101 sites were statistically over-represented in the upstream sequences of the 31 genes corresponding to the varying unique spots suggesting a possible link between pH regulation and metal response in B. cinerea. © 2012 The Royal Society of Chemistry.