Evaluating polymers interplay to investigate lignocellulose 1 recalcitrance

3D fluorescence maps on raw and hot-water pretreated CWR were performed using a JASCO FP8300 spectrofluorometer (Japan). The 3D maps were acquired with excitation wavelengths scanning from 300 to 550 nm, with a wavelength increment of 2 nm, emission wavelengths scanning from 350 to 600 nm, with wavelength increment of 0.2 nm. The sensitivity was set to 598 500 V. The 3D maps were analyzed with Jasco SpectraManager software.

and Yi is the initial content (raw CWR).

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B-Impact on the phenolic compounds 154          Table 4. LFD and LFAD was determined thanks to a conversion factor 248 of 0.57 nm per cellulose chain, and were schematically represented in Figure 3 (55, 56). 4.4 at 20 min to 3.8 after a HWP 40 min (Table 1). This acidification was negatively correlated 260 (R 2 = -0.89) with the increasing loss of amorphous cellulose from about 13-17% with the HWP 261 20 min to 36-38% with the HWP 40 min for M9 and M7, respectively.

262
HWP also induced changes in the ultrastructure of the cellulose by slightly increasing the LFD.   (Table 5). The HWP has modified the ultrastructure of the cellulose but also its interactions with 305 hemicelluloses/lignins making the microfibrils more accessible to water molecules. These  Simons' staining has shown that the HWP increased the relative amount and the expansion of  In complement, the relaxation times of the different CWR were analysed at a relative humidity 373 of 80% (w/w) in order to obtain more information on the effect of the HWP on the water 374 redistribution and the porosity (Fig. 6). An increase in the number of populations with higher

380
The first region of relaxation time from 4 to 30 ms (Fig. 6) corresponds to "small" pore sizes

458
Considering lignin organisation is a more relevant way to assess its impact on recalcitrance 459 than its content alone.

532
The consolidated severity factor (CSF) of these pretreatments was calculated according to For the global biochemical and physico-chemical analysis, the CWR were ground with an ultra 540 centrifugal mill (ZM200, Retsch, Germany) to an average granulometry of 1 mm.

542
The monomeric sugars content were quantified by HPAEC-PAD after a two-step H2SO4 543 hydrolysis as described previously (93).  Approximately 80 mg of each CWR were rehydrated to 24-26% (w/w) with ultra-pure water.

617
All the analyses were carried out as biological triplicates. The chemical shifts, half width and area of peak of samples were determined using a least-627 squares fitting method with the Peakfit ® software (Systat Software Inc., USA).

671
The aliquots were heated at 100 °C for 2 min, and then centrifuged at 12,000 g for 5 min. The  The initial reaction rate was calculated as the tangent to the hydrolysis curve, converted sugars 681 (g.L -1 ) plotted against reaction time (hours), at the initial time and was expressed in g.L -1 .h -1 .