Fungal contamination is common on historic paintings, manuscripts, and photographs. The growth of fungi on these cultural heritage materials has the potential to spoil their aesthetics, and damage their underlying structure. Current methods used for measuring fungal biomass, such as the microscopic estimation of biovolume and ergosterol analysis, are expensive and time consuming. Due to the sensitive nature of most cultural heritage materials these tests are also inappropriate for use with historic materials. There is a positive correlation between fungal enzyme activity (e.g., β-N-acetylglucosaminidase and endo 1,4-β-glucanase) and fungal biomass. We have previously described a method which involved the use of a fluorogenic 4-methylumbelliferyl labeled substrate (N-acetyl-β-D-glucosaminide) to detect fungal enzyme activity. Fluorescence increased linearly with the biomass of the fungusAspergillus niger. We have developed a nonfluidic assay in which the fluorogenic substrate is embedded on a filter paper strip. This assay strip can be used to swab surfaces that may harbor fungal material. A simple fluorimeter is sufficient to analyze the strips for the presence of fungal biomass. Using this simplified fluorimetric assay, we were able to detect fungal biomass in a variety of cultural heritage materials, including paper, canvas and photographic film. This fluorimetric assay is non-destructive and is a simple, rapid and inexpensive method for the detection and quantification of fungi on historic materials.
Full conference title:
- ASM 112th (2012)