Background:
Considering that the costs of cellulases and hemicellulases contribute substantially to the price of bioethanol, new studies to understand and improve cellulase efficiency and productivity are of paramount importance. Aspergillus niger has been shown to produce a wide spectrum of polysaccharide-hydrolytic enzymes. In order to understand how to improve enzymatic cocktails that can hydrolyze pre-treated sugarcane bagasse, we used a genomics approach to investigate which genes and pathways are transcriptionally modulated during growth of A. niger on steam-exploded sugarcane bagasse (SEB).
Results:
Here, we report the main cellulase- end hemicellulase-encoding genes with increased expression during growth on SEB. We also examined if the mRNA accumulation of several SEB-induced genes encoding putative transporters was induced by xylose and dependent on glucose. We identified 18 (58 % of A. niger predicted cellulases) and 21 (58 % of A. niger predicted hemicellulases) cellulases- and hemicellulases-encoding genes, respectively, that were highly expressed during growth on SEB.
Conclusions:
Degradation of sugarcane bagasse requires production of many different enzymes, which are regulated by the type and complexity of the available substrate. Our work opens new possibilities for understanding sugarcane biomass saccharification by A. niger hydrolases and for the construction of more efficient enzymatic cocktails for second generation bioethanol.Source:
http://www.biotechnologyforbiofuels.com/rss/