Unraveling disparate roles of organisms, from plants to bacteria, and viruses on built cultural heritage.

The different organisms, ranging from plants to bacteria, and viruses that dwell on built cultural heritage can be passive or active participants in conservation processes. For the active participants, particular attention is generally given to organisms that play a positive role in bioprotection, bioprecipitation, bioconsolidation, bioremediation, biocleaning, and biological control and to those involved in providing ecosystem services, such as reducing temperature, pollution, and noise in urban areas. The organisms can also evolve or mutate in response to changes, becoming tolerant and resistant to biocidal treatments or acquiring certain capacities, such as water repellency or resistance to ultraviolet radiation.

Long-amplicon MinION-based sequencing study in a salt-contaminated twelfth century granite-built chapel.

The irregular damp dark staining on the stonework of a salt-contaminated twelfth century granite-built chapel is thought to be related to a non-homogeneous distribution of salts and microbial communities. To enhance understanding of the role of microorganisms in the presence of salt and damp stains, we determined the salt content and identified the microbial ecosystem in several paving slabs and inner wall slabs (untreated and previously bio-desalinated) and in the exterior surrounding soil. Soluble salt analysis and culture-dependent approaches combined with archaeal and bacterial 16S rRNA and fungal ITS fragment as well as with the functional genes nirK, dsr, and soxB long-amplicon MinION-based sequencing were performed.

Dry biocleaning of artwork: an innovative methodology for Cultural Heritage recovery?

An innovative methodology is proposed, based on applied biotechnology to the recovery of altered stonework: the "", which envisages the use of dehydrated microbial cells without the use of free water or gel-based matrices. This methodology can be particularly useful for the recovery of highly-ornamented stoneworks, which cannot be treated using the conventional cleaning techniques. The experimental plan included initial laboratory tests on Carrara marble samples, inoculated with dehydrated Saccharomyces cerevisiae yeast cells, followed by on-site tests performed on "" (), a travertine monumental complex in Rome (Italy), on altered highly ornamented areas of about 1,000 cm.

Onsite advanced biocleaning system for historical wall paintings using new agar-gauze bacteria gel.

Aims: This study reports the results of the application of a new agar-gauze biogel system activated with viable bacterial cells to altered wall paintings.

Methods And Results: Biocleaning using agar biogel and agar-gauze biogel systems was performed onsite by direct application to altered wall painting surfaces (25-1000 cm ). The treatments were performed for the restoration of two original Italian sites: (i) at the Vatican Museums, Cristo che salva Pietro dalle acque-La Navicella, a wall painting by Giovanni Lanfranco (1627-1628) and (ii) at Pisa Cathedral Cupola, Incarnato, a wall painting by Orazio Riminaldi (1593-1630) and his brother Girolamo Riminaldi.

Hi-tech restoration by two-steps biocleaning process of Triumph of Death fresco at the Camposanto Monumental Cemetery (Pisa, Italy).

Aims: In this work, the 'hi-tech' complex biocleaning and restoration of the 14th-century fresco Triumph of Death (5·6 × 15·0 m) at the Camposanto Monumental Cemetery (Pisa, Italy) is reported. Since 2000, the restoration based on the biological cleaning of noble medieval frescoes, has been successfully utilized in this site.

Methods And Results: The novelty of this study is the two-steps biocleaning process using Pseudomonas stutzeri A29 viable cells, previously applied for recovering other valuable frescoes.