Assessing the Bioreceptivity of Biobased Cladding Materials

Materials exposed to the outdoors are prone to various deterioration processes. Architectural

coatings are designed to protect surfaces against environmental and biotic degradation and

to provide a decorative layer. The objective of this work was to examine the early colonisers on a

diverse set of coated and non-coated biobased façade materials. A set of 33 wood-based cladding

materials were exposed to four cardinal directions and monitored in outdoor conditions. The surfaces

were sampled using a wet swab and plated on DG-18 agar, which prevents the growth of bacteria

and limits the growth of fast-growing fungi. Pure cultures were then isolated and identified through

PCR amplification and Sanger sequencing of specific DNA regions/genes. The response of cladding

materials to weathering and fungal infestation was assessed. The proposed techniques enabled the

identification of features that promote/inhibit fungal colonisation and revealed the preference of

certain fungi for specific materials. Both the material type and the climate condition at the exposure

site influence fungal colonisation. This study is a starting point for more exhaustive assays that aim

to develop a novel coating system based on controlled and optimized fungal biofilm formation, and

is proposed as a nature-inspired alternative for the protection of architectonic surfaces.