In the context of biofuels and chemical production of petroleum substitutes from renewable carbon, bioconversion of lignocellulose biomasses is currently a major challenge. The limited knowledge of liquefaction and saccharification mechanisms stands as the main factor which penalizes bio-refinery progress. The objective of the present work was to increase the substrate concentration during hydrolysis in controlling transfer limitations by a specific strategy of substrate feeding. This concept was studied at laboratory scale and transposed into pilot scale. In-situ and ex-situ rheometry, morpho-granulometry and biochemical measurements were used to investigate transfer limitations. In a preliminary step (lab scale), rheological behaviour was modelled and a critical concentration (Ccrit ) inducing a sharp increase of viscosity was identified for Whatman paper (WP, 35 gdm.L-1) and paper pulp (PP, 31 gdm.L-1). Analysing hydrolysis experiments leads to assume an optimal feed rate Q* linked to this critical concentration. In a first step, cumulative feeding strategies (up to 10%w/w) were conducted for WP and PP in 2L reactor with different ratios Q/Q*. A cumulative feeding substrate strategy allows to considerably reduce the transfer limitations linked to high concentrations and to control the glucose production kinetics. In the second step, the enzymatic hydrolysis (up to 20%w/w) was investigated in a 20L reactor coupled with an extruder (substrate feeding). This transposition will be discussed regarding the biochemical kinetics and physical limitations.< Leer menos