It was observed in our experiment that fibre cutting is the predominant action in the enzymatic hydrolysis of lignin-free wood fibres, i.e. bleached kraft pulp fibres, and lignin-less wood fibres, i.e. unbleached organosolv pulp fibres. Enzymatic action was concentrated on specific regions and fibres were quickly cut through, generating shorter segments. This cutting action not only increases the overall specific surface area of the substrate but creates new lumen openings on the fibres, dramatically increasing the available surface area for enzymes. Accelerated hydrolysis rates in the subsequent process confirmed this speculation.

Localized morphological changes on the fibre wall, referred to as “dislocation” or “slip plane”, have also been observed in the pulp and paper process. It has been suggested that “dislocation” or “slip plane” is due to changes in cellulose microfibril orientation caused by wind action in trees, wood/chip cutting, chemical treatment in pulping processes and physical action in pulp refining and pulp transport processes. It is apparent that the localized morphological change benefits the enzymatic hydrolysis of the fibre substrate. If we can utilize these localized morphological changes in developing novel pretreatment technologies, the efficiency of enzymatic hydrolysis can be expected to improve.