Microbial communities affecting albumen photography heritage: a methodological survey

Abstract

This study is one of the few investigations which analyze albumen prints, perhaps the most important photographic heritage of the late 19(th) and early 20(th) centuries. The chemical composition of photographic samples was assessed using Fourier-transform infrared spectroscopy and X-ray fluorescence. These two non-invasive techniques revealed the complex nature of albumen prints, which are composed of a mixture of proteins, cellulose and salts. Microbial sampling was performed using cellulose nitrate membranes which also permitted the trapped microflora to be observed with a scanning electron microscope. Microbial analysis was performed using the combination of culture-dependent (cultivation in different media, including one 3% NaCl) and culture-independent (bacterial and fungal cloning and sequencing) approaches. The isolated microorganisms were screened for their lipolytic, proteolytic, cellulolytic, catalase and peroxidase activities. The combination of the culture-dependent and -independent techniques together with enzymatic assays revealed a substantial microbial diversity with several deteriogen microorganisms from the genera Bacillus, Kocuria, Streptomyces and Geobacillus and the fungal strains Acrostalagmus luteoalbus, Bjerkandera adusta, Pleurotus pulmonarius and Trichothecium roseum.

Figure 1. Gyula photograph.

(a) The albumen surface is 9.7 × 13.9 cm; the size of the complete photograph including the cardboard is 10.8 × 16.2 cm. The microbial sampling sites are marked with two red circles. The sites F0–F4 were subjected to FTIR analysis, while the letters XA–XC indicate the sites where XRF measurements were performed. (b,c) Stereo microscope images with a magnification of 40× (site F4) and 20× (area near to site F4) respectively. (d,e) SEM photographs showing the fungal hyphae and spores recovered by a cellulose nitrate membrane. The photograph was supplied by the Slovak National Archive and is used with permission.

Figure 2. Antiquarian photograph.

(a) The albumen surface measures 10.1 × 13.9 cm; the size of complete photograph including the cardboard is 10.9 × 16.6 cm. Numbers 1–6 indicate the sites where FTIR measurements were taken, while sites A–C were subjected to XRF examination. (b) A 20× stereo microscope image of site 6 (c,d) SEM photographs of site 2 where the presence of fungal hyphae and possible mineral structures is evident.

Figure 3. ATR-FTIR spectra of the two albumen prints, Gyula and antiquarian.

Figure 4. Comparison of μ-FTIR spectra between control site (F0) and the foxing site F4 of the Gyula print.

Figure 5. Microbial communities detected in photographic samples.

Bacterial (a) and eukaryotic (b) diversity on photographic materials detected using the DGGE and clone library approach. P1: Gyula photo from Slovak National Archive; PF1: album paper frame of Gyula photo; PA2: antiquarian photograph.

Figure 6. Percentage of hydrolytic abilities of isolated microflora.

Distribution of hydrolytic activities of microorganisms isolated from different samples. P1: Gyula photo from Slovak National Archive; PF1: album paper frame of Gyula photo; PA2: photograph from antiquarian.