Rapid diagnosis of microbial growth and biocide treatments on stone materials by bioluminescent low-light imaging technique

Abstract

Chemical treatments to prevent and control microbial growth are considered as one of the effective means for artworks preservation including stone materials. Several characteristics and related techniques should be taken into account in selecting an "adequate" chemical treatment —selection and use of biocides, their effects, toxicity, modes of applications, and risk of environmental pollutions. This chapter describes the bioluminescent low-light imaging technique, which is based on determination of ATP content, for rapid diagnosis of microbial growth and for optimizing the biocides selection to monitor their effects after short and long intervals in conservation of stones and monuments. Four stone specimens that differ in rock crystalline structures and porosity were tested. Four test strains were used in the study, including E. coli Pseudomonas fluorescens, Achromobacter sp., and Bacillus subtilis. Quantitative determinations of viable microbial counts, after addition of biocide solution on stone specimens tested, were carried out by bioluminescent low-light imaging technique and ATP assay. The chapter discusses the results and peculiarities of this technique. A linear relationship between bioluminescent signals and dilution of pure culture of bacterial cells adopted as standard was observed. The routinely utilization of the bioluminescent low-light imaging technique is important in the study of recovery and monitoring on stone materials related to cultural heritage, especially when biocide treatments are required.