Bioinspired living coating system for wood protection

The bioinspired living coating system offers an innovative, sustainable approach to wood protection, relying on natural substances with minimal environmental impact and low maintenance requirements. While promising as an alternative to conventional coatings, key aspects remain poorly understood. Although Aureobasidium pullulans (A. pullulans) has been identified as the optimal fungal species, it is essential to further validate that this fungus meets crucial criteria for effective protection. Additionally, the impacts of natural weathering on substrate properties, bioreceptivity, microbial colonization rates, and the survival of fungal cells within the coating under varied conditions require further investigation. This thesis aims to 1) explore A. pullulans' resilience in biofilm formation across different wood substrates and environmental conditions, 2) assess the performance of wood treated with this biofilm-based coating, and 3) examine fungal cell survival throughout its service life. The evaluation of fungal colonisation on wood surfaces exposed to diverse climate conditions and a range of coated and non-coated biobased façade materials revealed that specific species, notably A. pullulans, emerged as predominant primary colonisers on weathered wood surfaces, regardless of geographical location, cardinal direction, and surface treatment. The adaptability and capacity to thrive in a relatively broad range of ecological conditions make this fungal strain suitable as a protective layer for building materials. The assessment of fungal colonisation on wood surfaces coated with Biofinish following a 9-month exposure period revealed that the majority of the detected species belonged to the genera Aureobasidium, specifically A. pullulans. These results indicate the survival and effective antagonistic action of A. pullulans, the living and active ingredient of the coating, against other wooddecaying fungi. The performance of Scots pine (Pinus sylvestris L.) wood treated with Biofinish was evaluated against uncoated reference wood following a 12-month natural weathering trial. Biofinish exhibited superior performance across all examined aspects compared to the uncoated reference. The entirely bio-based composition of the Biofinish coating enhances its sustainability and compatibility with natural environments, rendering it an appealing alternative to contemporary wood surface protection solutions. The results from this thesis will facilitate the control and optimisation of fungal biofilm and contribute to the development of novel bioinspired protection coatings based on optimised fungal biofilm working in synergy and not against nature.