Two-stage fungal biopulping for improved enzymatic hydrolysis of wood

Abstract

A novel two-stage, whole organism fungal biopulping method was examined for increasing the yield of enzymatic hydrolysis of wood into soluble glucose. Liriodendron tulipifera wood chips (1g) were exposed to liquid culture suspensions of white rot (Ceriporiopsis subvermispora) or brown rot (Postia placenta) fungi and incubated at 28°C, either alone in single-stage 30 day (one fungal species applied) or two-stage 60 day (both fungal species applied in alternative succession) treatments. Fungi grew in all treatments, but did not significantly decrease the percent carbohydrate content of the wood. Two-stage treatments differed significantly in mass loss depending on order of exposure, suggesting additive or inhibitory fungal interactions occurred. Treatments consisting of C. subvermispora followed by P. placenta exhibited 6 ± 0.5% mass loss and increased the yield of enzymatic hydrolysis by 67-119%. This significant hydrolysis improvement suggests that fungal biopulping technologies could support commercial lignocellulosic ethanol production efforts if further developed.