Reduction in Enzyme Dose Requirement Through Use of Enzymatic PreConditioning

Realization of a commercially relevant biochemical route cellulosic biorefinery process depends upon several main cost factors; namely capital charge, feedstock price, enzyme hydrolysis and fermentation (most often, in that order of importance).  The most competitive producers will deploy advanced enzymes into advanced hydrolysis designs in order to minimize the enzyme load needed to reach the desired sugar yields within the necessary process times.  For several years, Novozymes has developed a special step prior to enzyme hydrolysis called PreConditioning.  In this simple unit operation, stable pH and temperature combined with the right amount of time significantly improves process stability, hydrolysis kinetics and/or cellulose conversion when applied to NREL unwashed dilute acid pretreated corn stover. 

In this presentation, inclusion of enzymes into this step, a so-called “Enzymatic PreConditioning”, will be discussed.  Using this technique, reductions in commercially relevant Cellic CTec3 doses were reduced by more than 1.5x.  Impacts on cellulose conversion, process robustness and process design at large scale will be shown, in addition to experiences identifying the right enzyme activities to give the effect for a variety of different feedstocks and pretreatments.