Preliminary investigations into the action of nitric oxide in the control of biodeterioration

Abstract

Environmental control is the preferred and often the most appropriate response in the prevention of biodeterioration of cultural materials. For immoveable heritage or objects housed under conditions where temperature and humidity favour the processes of biodecay, however, chemical-based biocide treatments are often required. Unfortunately, the potential for treatment damage, and the significant adverse environmental and personal health implications of using chemical biocides are a major consideration in their use. Therefore investigation into, and development of, less invasive and less toxic treatment methodologies are sought (Young et al. 2008). The observed antimicrobial properties of the free radical molecule nitric oxide (NO•) have led to the application of nitric oxide donor compounds in the control of biofilm formation on medical implants, and as antifoulants in the marine biofouling and coating industries (Barraud et al. 2006; Nablo, Rothrock & Schoenfisch 2004). In researching alternative methods for the treatment of biodeterioration in conservation, preliminary investigations into the suitability of nitric oxide-based treatments were undertaken. The NO• used in this study originates from two sources: a direct source in the form of a nitric oxide releasing compound, the nitric oxide donor DETA/NO•; and an indirect source in which NO• is produced from the reduction of nitrate by nitrate reducing bacteria. Test populations for this study included Pseudomonas aeruginosa PAO1, a known nitrate reducer, and a mixed population representative of microorganisms from various samples of cultural material.