Comparison of enzymatic hydrolysis in a worldwide round robin assay

Abstract

Within the IEA activity on Pretreatment of Lignocellulosic Materials, a number of laboratories performed enzymatic hydrolyses of a standard cellulose and pretreated spruce and aspen wood under strictly standardized conditions. The reproducibility of the time dependence of hydrolysis was examined by incubating Sigmacell 50 (20 g/litre) with a standard cellulase (Celluclast, Trichoderma sp.), 200 FPU/litre, at pH 4·8, 50°C. The liberated glucose was determined by HPLC or by the glucose oxidase method after 6, 24, 48 and 72 h. The individual deviation from the mean values of 11 laboratories was in the range 5–10%. In the enzyme-dependent hydrolysis, Sigmacell 50 was incubated with increasing amounts of Celluclast (5–100 FPU/g, 24 h). Based on the liberated glucose, the maximum digestibility of Sigmacell 50 calculated by 11 laboratories was 64·3±3·7% (mean±standard deviation). Similar reproducibility was obtained with pretreated aspen and spruce wood. This inter-laboratory comparison indicates that both tests, the time-dependent and the enzyme-dependent hydrolysis methods, are reproducible tools to evaluate the enzymatic hydrolysability of lignocellulosics for technical applications.