## 2 Materials and Methods
### Analytical Methods  
Before chemical analyses, all the materials underwent grinding on a Cyclotec 1093 mill (Foss Analytics, Hilleroed, Denmark) endowed with a 1-mm sieve to make their granulocyte uniform. The determination of the crude lipids was carried out gravimetrically after extracting the solid culture samples and the relative incubation controls (3.0 g) in the Buchi B-811 automated Soxhlet apparatus (Uster, Switzerland) with petroleum ether (boiling range 313-333 K) for 6 h, as described by [PERSON] et al. [18]. Neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) were determined on defatted samples in a Fibertec System M 1020 Tecator (Foss Analytics, Hilleroed, Denmark) using the method of [PERSON] et al. [19]. Hemicellulose was calculated as NDF-ADF and cellulose as ADF-ADL [20], while the ash content in ADL was subtracted from ADL to calculate Klason lignin. Total phenols were determined both on the liquid derived from the hydraulic pressing of solid-state cultures and the resulting residual solid. In the latter case, the material underwent extraction for 4 h at 323 K with a water:methanol mixture, at a volume fraction of 0.50, using a solid:liquid ratio of 0.1 g cm\({}^{-3}\), before being analyzed with the procedure of [PERSON] and [PERSON] [21], using catechol as the standard. The determination of reducing sugars relied on a 3,5-dinitrosalicylic acid reagent [22]. The elemental analyzer for solids Vario MacroCube of Elementar Gmbh (Langelselbold, Germany) enabled the determination of the percentage contents in carbon, hydrogen, nitrogen and sulfur and the calibration of the measurements relied on sulfonamide, used as the standard. The ash content was determined after the ignition of samples in a muffle furnace at 823 K for 8 h. The calculation of the organic matter losses (OML, %) relied on the variations in the ash content recorded in the solid phase cultures (\(x_{scsc}\)) compared to the respective incubation controls (\(x_{ic}\)) according to Equation (1), suggested by [PERSON] et al. [23]  
\[\text{OML }(\%)=100-\left[\frac{x_{ic}\times(100-x_{scsc})}{x_{scsc}\times(100-x_{ ic})}\times 100\right] \tag{1}\]  
The degree of colonization in solid-state cultures was inferred from both visual inspections and indirectly through a fungal-specific marker represented by D, a fungal wall polymers component. In particular, acid hydrolysis and deacetylation of the colonized material relied on the procedure described by [PERSON] et al. [24], except for the extract's neutralization step, which used solid sodium carbonate. d-glucosamine was spectrophotometrically determined at 530 nm, as reported elsewhere [25]. The same approach was applied to incubation controls to assess the possible presence of d-glucosamine in solid substrates. Soluble protein was determined in the crude extracts derived from the hydraulic pressing of both solid-state cultures and respective incubation controls by the dye-binding method, using bovine serum albumin as the standard [26]. Soluble protein contents in incubation controls were subtracted from those found in the respective solid-state cultures.