Beta-Glucosidase for Biofuel Application
CSIR-NIIST had isolated a filamentous fungus from decaying wood in 2005, which was identified as Aspergillus niger
and designated isolate no. NII 08121. The fungus produced a BGL which was active at 0.5M glucose and had a glucose inhibition constant (Ki) of 0.2M. The technology developed is a solid state fermentation process for the production of NII 08121 BGL.
Beta-Glucosidase (BGL) is a key ingredient in the enzyme blends used for biomass hydrolysis for bioethanol production. It is the rate-limiting enzyme in the cellulase complex. Cellulases for hydrolysis of biomass are typically sourced from fungi like Trichoderma reesei whose cellulases lack sufficient quantities of this important enzyme. Commercial preparations of cellulase contain BGL from heterogeneous sources. Aspergilli are used as sources of BGL. Globally, there are only a few suppliers of BGL for biomass hydrolysis. BGL in these preparations are inhibited by high concentrations of glucose.