Lignocellulose is a complex substrate which requires a variety of enzymes, acting in synergy, for its complete
hydrolysis. These synergistic interactions between different enzymes have been investigated in order to design
optimal combinations and ratios of enzymes for different lignocellulosic substrates that have been subjected to
different pretreatments. This reviewexamines the enzymes required to degrade various components of lignocellulose
and the impact of pretreatments on the lignocellulose components and the enzymes required for degradation.
Many factors affect the enzymes and the optimisation of the hydrolysis process, such as enzyme ratios,
substrate loadings, enzymeloadings, inhibitors, adsorption and surfactants. Consideration is also given to the calculation
of degrees of synergy and yield. A model is further proposed for the optimisation of enzyme combinations
based on a selection of individual or commercial enzyme mixtures. The main area for further study is the
effect of and interaction between different hemicellulases on complex substrates.