*The molar ratio of xylose and arabinose units is reported in brackets.
**The molar ratio of xylose units and acetyl groups is reported in brackets.
The composition is presented as percentage of total dry weight (DW) of substrate. The sugars are given as anhydro sugars. Phenolic acid esters were measured after mild alkali extraction; the sum of phenolic acid esters and ethers was measured after severe alkali extraction . The composition of the H58 fractions was adapted from Costa et al..