The correlation between surfactant concentration and increase in cellulose conversion showed that the effect leveled off at concentrations above approximately 0.025 g (g DM)−1.
An explanation as to why the leveling off and optimum concentration were equal for different substrates may be that all possible binding sites on lignin are occupied by surfactant when it reaches a certain concentration, irrespective of the ability of
the substrate to unspecifically bind enzymes.
Thus, there may be a number of potential sites on the lignocellulose that may either
adsorb enzyme or surfactant. When these sites are all associated with surfactant, further addition will not increase hydrolysis.