(671f) A Survey of Wood-Degrading Fungi for Biological Pretreatment of Lignocellulose

The diversity of wood-degrading fungi suggests a wealth of potential for lignocellulose conversion for biofuels.  Previous studies have considered wood-degrading fungi for various biotechnology applications, including direct biological pretreatment.  Fungi previously considered, however, have often been model organisms that have been well studied for reasons unrelated to bioconversion.  This study aimed to broaden the pool of fungi considered for bioconversion beyond these model organisms.  Aspen blocks were exposed to forty field isolates of wood-degrading fungi, including several unidentified species, for two or four weeks.  Top performing isolates were selected for a refined time series study on aspen.  A representative hardwood (aspen), softwood (pine), and grass (corn stalk), were also used to determine the potential improvement in saccharification potential of the top performing fungi.  A selective white-rot isolate, Scytinostroma sp., provided the greatest improvement in aspen saccharification, achieving a glucan to glucose conversion yield of up to 56.3%, a 3.8 fold increase over the control.  Follow-up with three isolates of Scytinostroma sp. showed that all provide comparable saccharification improvement on both pine and aspen.  These findings suggest that consideration of a broader range of fungal isolates may prove fruitful in finding fungi that are well suited for bioconversion.