Pretty in pink? The microbiome on historic buildings

The increased salt concentration forms an ecological niche for halophilic (salt-loving) microorganisms. Many of these microorganisms contain carotenoids that cause pink discolouration and thus additional aesthetic damage.

Two historical buildings, the Virgil Chapel and the Mauerbach Charterhouse, which show salt-related damage, serve as empirical models. In the project, microclimatic parameters are monitored and the microbial community is analysed with the aim of evaluating a newly designed treatment to reduce the salt concentration.

In addition, salt-loving bacteria will be studied in vitro to understand the changes in the microbial community in response to artificially elevated salt concentrations. Novel metagenomics and transcriptomics approaches will be applied in a combination of next- and third-generation sequencing methods to study the genome and gene activity of these bacteria. 
The realisation of this project requires a coordinated, interdisciplinary consortium of experts from the fields of microbiology, molecular biology, bioinformatics and conservation-restoration.

The results of the project create the basis for the long-term restoration of salt-contaminated, historical cultural monuments. A better understanding of microbial succession under salt stress and the metabolic processes that play a role in this will help to counteract the damage to our historical artefacts and make a significant contribution to the development and application of effective conservation measures.