UV-Induced Mutations as Drivers of Fungal Adaptation to Complex Biomass

UV-CELIUM is a research project aimed at generating new scientific knowledge on how ultraviolet light (UVA, UVB and UVC), applied in a controlled manner using multi-wavelength UV-LED systems, can induce physiological, genomic and structural adaptations in edible filamentous fungi, as well as chemically transform agro-industrial by-products to facilitate their colonisation and convert them into high added-value biomaterials. The proposal responds to the priorities of the State Plan in bioeconomy, sustainability, circularity and the production of advanced biomaterials. The project is based on the hypothesis that sublethal and modulated UV exposures act as targeted stimuli capable of (i) remodelling the metabolism and growth patterns of edible fungi, favouring the formation of cohesive mycelial networks in recalcitrant agro-industrial by-products, and (ii) modify the phenolic composition, lignocellulosic structure and microbial load of agro-industrial waste, reducing its inhibition and increasing its bioaccessibility. Furthermore, it is proposed that (iii) the strategic combination of UV-preconditioned fungi and similarly photo-modified matrices will generate synergistic effects that will result in faster and more homogeneous colonisation and in mycelial materials with superior mechanical and viscoelastic properties to those obtained through independent treatments. The methodology is structured into three complementary work packages. WP1 studies fungal responses to UVA/B/C under controlled conditions, characterising growth, metabolic stress (purines), biomass composition (ergosterol), mycelial architecture and initial rheological properties. WP2 evaluates how UV radiation alters the phenolic composition, microstructure, photo-reactivity and microbial ecology of representative agro-industrial waste (almond shells, brewer spent grains, coffee grounds). WP3 integrates both blocks to determine whether double UV preconditioning (fungi + substrates) improves colonisation efficiency in solid-state fermentation and the quality of the resulting biomaterial, characterised by rheology, multiscale structural analysis and performance metrics. The project combines advanced techniques (programmable UV-LED, HPLC-UV, LC-MS/MS, SEM, FTIR, rheometry, 16S RNA/ITS microbiome analysis, genomics/transcriptomics) with a robust statistical approach based on response surface designs and multivariate analysis. The research will be carried out by a team with extensive experience in UV technology, food safety, mycology and biomaterials, with international advisory support in fungal genomics (ISPA-CNR, Italy) and sustainable and safe bioprocesses (TUDublin, Ireland). The expected results will provide new mechanisms for UV-induced fungal adaptation, photochemical principles applicable to the detoxification of agro- industrial waste, and scientific criteria for the design of mycelial biomaterials from complex matrices. UV-CELIUM will lay the foundations for future applications in sustainable packaging, bioproducts, functional ingredients, and circular economy platforms based on clean, low-energy fermentation.