ABSTRACT
The major barrier to the development and cost reduction of biochemical cellulosic ethanol, and the implementation of related biorefineries, is the recalcitrance of the cell wall to the enzymatic attack. In particular, the compact structure of crystalline cellulose and its embedding in a matrix of lignin and hemicelluloses impede enzymatic access. Therefore, in order to reduce complexity and costs of the exploitation of cellulose feedstock, improved biochemical systems to access and hydrolyze cellulose have to be developed, yields in the fermentation steps have to be improved, and biomass pretreatment conditions have to be optimized. The objective is to bridge the current cost gap between cellulosic ethanol and corn ethanol, which is estimated to be between $0.7 and $1.5 per gallon.
