Caroline Kyi PhD candidate Centre for Cultural Materials Conservation and ARC Centre of Excellence for Free Radical Chem

1. Alternative approaches in the treatment of biodeterioration of cultural materials, using the free-radical nitric oxide (NO) Caroline Kyi PhD candidate Centre for Cultural Materials Conservation and ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Melbourne

2. Centre for Cultural Materials Conservation Micro Organisms Macro Organisms

3. Centre for Cultural Materials Conservation ECOLOGICAL FACTORS Primary colonisers Bacteria Fungi Bryophytes Micro-degradation Symbiotic relationships Pioneer stage Lichens Higher plants Increase in biomass and metabolic activity Mature stage Increased biodiversity Biodeterioration Macro-degradation time 3: Altered material: degradation SUBSTRATE BIORECEPTIVITY 2: Added material: intervention, atmosphere 1: Original material: organic/inorganic

4. Centre for Cultural Materials Conservation General approaches in the treatment of biodeterioration Preventative: Influenced by the material being treated and its environment. Reducing biodeteriorgens Climate control Direct methods: Requires development of specific intervention criteria Physical Chemical Bioremediation Biocide being brushed onto the back of a canvas (top) and sprayed onto a stone monument (bottom) Caneva, et al, (eds) PLANT BIOLOGY FOR CULTURAL HERITAGE: BIODETERIORATION, 2008 The J. Paul Getty Trust, Los Angeles.

5. Centre for Cultural Materials Conservation An alternative treatment approach utilizing nitric oxide (NO) Background Free radical molecule of research interest Produced by natural and anthropogenic activities Therapeutic agent Atmospheric pollutant (NOx) Possesses antimicrobial properties Lewis structure of nitric oxide molecule showing paired (-) and unpaired () electrons

6. Centre for Cultural Materials Conservation Nitric oxide has previously been shown to induce biofilm dispersal Inhibition of the successful establishment of communities of micro-organisms by disrupting biofilm formation

7. Centre for Cultural Materials Conservation Centre for Cultural Materials Conservation 7

8. Centre for Cultural Materials Conservation Retrieval of a representative community Nutrient dependant Slow growers Polymicrobial cultures/biofilms Nitrate reducers? Establishment of cultural materials broth (CMO)

9. Centre for Cultural Materials Conservation Imaging of nitric oxide in association with bacterial cells

10. Centre for Cultural Materials Conservation Introduced nitric oxide: Selection of a nitric oxide donor Diazeniumdiolate DETA-NO Half life 24 hours at 22-25°C Minimal cytotoxic effects of by-products Adverse effects of compound on materials? 1-[N(2-Aminoethyl)-N-(2-ammoniethyl)amino]dizen-1-ium-1,2-diolate (DETA/NO)

11. Centre for Cultural Materials Conservation Evidence of inhibition of growth and poor formation of biofilms Synergistic relationship with antibiotics and biocides Considerations Compare effect of introduced and bioremedial forms of NO Examine donor effect using probe Effect on materials Introduced nitric oxide: Preliminary results

12. Centre for Cultural Materials Conservation • Experimental • Further and comparative testing of DETA/NO • Improved and increased application of probe • Investigations involving cultural materials • Determination of composition cultural material organisms stock broth 2012 onwards