Future prospects of biocleaning application in textile conservation

Abstract

Studies of sustainable preservation methods are an important element of ongoing research into minimising the environmental impact of conservation treatment. Of these methods, the cleaning of antique surfaces using selected microbial cultures is attracting attention in the field of heritage conservation. Due to the highly specific nature of the action of these microorganisms, which is similar to enzymatic cleaning, it is generally assumed that individual cultures can remove dirt without endangering the complex structures of textiles. The emphasis is placed on the use of nonpathogenic microbial cultures that have proven to be effective in the cleaning of other historical materials, and which are active in a neutral environment and show relevant metabolic activity. The aims of this work were to study the application of Pseudomonas putida to clean iron gall ink staining and the feasibility of using a selected bacterial strain to clean historic textiles. A relevant procedure for the application of this method to the controlled biocleaning of textiles was also developed. The use of water-based gel systems as a matrix for microorganisms seems to be optimal in terms of providing suitable living conditions for the bacteria and maintaining controlled contact with the surface of the object while simultaneously ensuring efficiency. Tests were carried out on appropriately prepared model samples consisting of cotton and silk. The changes emerging on the surface were evaluated using optical microscopy, and the rate of cleaning was assessed using FTIR and colorimetric methods. In addition, FTIR spectroscopy was employed for microbial control after biocleaning. The research demonstrates the feasibility of cleaning iron gall ink from textiles with viable microbial cells. The selected microorganism was able to reduce undesired discolouration from iron gall ink on model textiles. The results indicate that P. putida has a profound impact on silk samples, and prove that microbial cleaning can achieve a high level of efficiency in the removal of concentrated dirt.