Characterization of a novel sugar transporter involved in sugarcane bagasse degradation in .

BACKGROUND

is a saprophytic fungus implicated in the degradation of polysaccharides present in the cell wall of plants. has been recognized as the most important industrial fungus that secretes and produces cellulase enzymes that are employed in the production of second generation bioethanol. A few of the molecular mechanisms involved in the process of biomass deconstruction by ; in particular, the effect of sugar transporters and induction of xylanases and cellulases expression are yet to be known.

RESULTS

In our study, we characterized a novel sugar transporter, which was previously identified by our group through in silico analysis of RNA-seq data. The novel 69957-sugar transport system () is capable of transporting xylose, mannose, and cellobiose using a 69957-sugar transport system in . The deletion of in affected the fungal growth and biomass accumulation, and the sugar uptake in the presence of mannose, cellobiose, and xylose. Molecular docking studies revealed that shows reduced protein-ligand binding energy for interactions towards disaccharides in comparison with monosaccharides. Furthermore, the deletion of affected the gene expression of cellobiohydrolases ( and ), β-glucosidases ( and ), and xylanases ( and ) in the cultures of parental and mutant strains in the presence of cellobiose and sugarcane bagasse (SCB).

CONCLUSION

The transporter of can transport cellobiose, xylose, and mannose, and can affect the expression of a few genes encoding enzymes, such as cellulases and xylanases, in the presence of SCB. We showed for the first time that a filamentous fungus () contains a potential mannose transporter that may be involved in the degradation of cellulose.