Biological colonization of archaeological ceramics and disinfection with silver nanoparticles misting [Presentación de póster]

Abstract

Archaeological ceramics are materials of cultural heritage, the biodeterioration of which, has not often been studied. The archaeological samples came from La Cuestecilla, Antinaco Central Valley, La Rioja province, Argentina. They were collected and, then analysed by different methods namely: optical microscopy (Olympus BX 51), scanning electron microscopy (FEI Quanta 200), and energy dispersive X-ray analysis [1]. The microbiological contaminants were classified by conventional techniques with molecular identification. Silver nanoparticles (AgNPs, 10-80 nm, 90 ppm, 8 cycles) in the form of mist were applied in the specially designed chamber [2]. The effectiveness of silver nanoparticles misting was also undertaken using plate count method by shaking samples (control and after disinfection) in sterile saline. We have been able to observe cyanolichens growing on ceramics, which were seen to be weakened at the surface and edges. Fungal and bacterial development into the substratum was mostly via cracks and fissures, causing a breakdown of the material and severe deterioration. We have isolated and identified fungi, including members of the dematiaceous genera Cladosporium, Curvularia, and hyaline taxa including Aspergillus niger together with a species of Penicillium. Bacteria, including Bacillus atrophaeus, Achromobacter agilis and Pseudomonas aeruginosa with ability to form biofilms were also identified. The silver nanoparticles disinfection, decreased the number of microorganisms from 103 cfu/g to 102 cfu/g and did not the change optical properties of ceramics.